2024-03-28T08:50:36Zhttp://nur.nu.edu.kz/oai/requestoai:nur.nu.edu.kz:123456789/1762018-08-15T03:49:32Zcom_123456789_178com_123456789_86com_123456789_67col_123456789_179
Байтелиева, Жанар
2015-06-08T04:14:53Z
2015-06-08T04:14:53Z
2014-05-09
http://nur.nu.edu.kz/handle/123456789/176
Мақаланың зерттеу мақсатына қазақ халқының жылқы өсіру мәдениеті және оның тілдегі көрінісі жатады. Сондай-ақ, мақалада қазақ халқының жылқы өсіру мәдениетінің тарихы ғалымдардың деректеріне сүйене отырып талданады, салыстыру әдістерімен анықталады. Мақала мазмұны этнокультуралогиялық мәселелерді шешуді қамтиды.
tr
at yetiştirme kültürü
etnokültürel
kazak kültürü
türk tarihi
ат өсіру мәдениет
этномәдениеттану
қазақ мәдениеті
түрік тарихы
KAZAKLARDAKİ AT YETİŞTİRME KÜLTÜRÜ
Article
oai:nur.nu.edu.kz:123456789/1802018-08-15T03:49:32Zcom_123456789_178com_123456789_86com_123456789_67col_123456789_179
Байтелиева, Жанар
2015-06-08T06:00:55Z
2015-06-08T06:00:55Z
2009
http://nur.nu.edu.kz/handle/123456789/180
Мақалада түркі тілдеріндегі жылқы малына қатысты фразеологиялық тіркестердің лексика-семантикалық мәні қарастырылады. Атап айтқанда, қазақ, қырғыз, түрік тілдерінде кездесетін жылқыға қатысты фразеологиялық тіркестердің түрлі мағыналары талданады.
other
фразеологизмдер
жылқы малы
лексика-семантикалық мағынасы
диалектілік фразеологизмдер
этнолингвистика
ұлттық таным
салт-дәстүр
Түркі тілдеріндегі жылқы малына қатысты фразеологиялық тіркестердің лексика-семантикалық мәні
Article
oai:nur.nu.edu.kz:123456789/1812018-08-15T03:49:32Zcom_123456789_178com_123456789_86com_123456789_67col_123456789_179
Байтелиева, Жанар
2015-06-08T06:06:35Z
2015-06-08T06:06:35Z
2013-05
http://nur.nu.edu.kz/handle/123456789/181
Мақалада тілді оқытудың әдіс-тәсілдері сөз болады. Соның ішінде соңғы уақытта жиі айтылып жүрген функционалды грамматиканың практикадағы қолданысы туралы айтылады.
other
құрылымдық грамматика
функционалды грамматика
өріс категориясы
функционалды-семантикалық өріс
Тіл үйретуде пікір айтудың тілдік құралдарын меңгерту әдістері
Article
oai:nur.nu.edu.kz:123456789/1822018-08-15T03:49:31Zcom_123456789_178com_123456789_86com_123456789_67col_123456789_179
Байтелиева, Жанар
2015-06-08T06:11:53Z
2015-06-08T06:11:53Z
2008
http://nur.nu.edu.kz/handle/123456789/182
Бұл мақалада «жылқы» ұғымының мәдени, тарихи, этнографиялық, тілдік т.б. тұрғыдан зерттелу жайы айтылады. Осы аспектілердегі төрт түлік атауларын қарастырған әдебиеттерге шолу жасалып, ондағы зерттеу әдістері сөз болады.
other
құрылымдық грамматика
жылқы ұғымы
этнолингвистика
этнография
мәдениет
этнос тарихы
ғылыми әдебиеттер
Жылқы ұғымының мәдени, тарихи, этнографиялық, тілдік т.б. тұрғыдан зерттелу жайы
Article
oai:nur.nu.edu.kz:123456789/1832018-08-15T03:49:31Zcom_123456789_178com_123456789_86com_123456789_67col_123456789_179
Байтелиева, Жанар
2015-06-08T06:27:42Z
2015-06-08T06:27:42Z
2010-04
http://nur.nu.edu.kz/handle/123456789/183
Бұл мақалада имитатив теориясының қазақ тіл білімінде қолданылып жүрген терминдері туралы айтылады. Осы салада қолданылатын терминдерге сипаттама беріліп, мағыналары туралы түсінік беріледі, ғалымдардың пікірлеріне талдау жасалады.
other
лингвистикалық терминдер
имитатив теориясы
арнаулы лексика
қазақ тіл білімі
ИМИТАТИВ ТЕОРИЯСЫНЫҢ ТЕРМИНДЕРІ ЖАЙЫНДА
Article
oai:nur.nu.edu.kz:123456789/2022018-08-15T03:49:31Zcom_123456789_178com_123456789_86com_123456789_67col_123456789_179
Байтелиева, Жанар
2015-06-19T08:07:09Z
2015-06-19T08:07:09Z
2014-11-07
http://nur.nu.edu.kz/handle/123456789/202
Мақалада мақал-мәтелдерді этнолингвистикалық тұрғыдан зерттеудің маңыздылығы қарастырылады. Сондай-ақ, осы мәселенің Ә.Қайдар еңбектерінде зерттелуіне басымдық беріледі
other
мақал-мәтелдер
этнолингвистика
ұлттық таным
салт-дәстүр
этнос тарихы
Мақал-мәтелдерді этнолингвистикалық тұрғыдан зерттеудің маңыздылығы
Article
oai:nur.nu.edu.kz:123456789/2032018-08-15T03:49:31Zcom_123456789_178com_123456789_86com_123456789_67col_123456789_179
Байтелиева, Жанар
2015-06-19T08:14:59Z
2015-06-19T08:14:59Z
2015-03-27
http://nur.nu.edu.kz/handle/123456789/203
Бұл баяндамада тілдік білімді бағалау жүйелерінің қалыптасуы мен даму барысы сөз болады. Бүгінгі көптілді әлемде бірнеше тілдерді меңгеру заман талабы болып отырғандықтан үйренген екінші, үшінші тілді бағалаудың да өзектілігі туындап отыр. Осыған орай тілдік білімді бағалайтын халықаралық танымал тестілердің қалыптасу, даму бағытын сөз етеміз және осы жүйелерді қарастыру арқылы өз тәжірибемізді арттыру мақсатын көздейміз.
other
тілдік білім
тілдік білімді бағалау
бағалау жүйелері
тест
екінші тіл
сөйлесім әрекеттері
тілдік деңгей
коммуникативтік құзірет
халықаралық жүйелер
Тілдік білімді бағалау жүйелерінің мәселелері
Article
oai:nur.nu.edu.kz:123456789/2042018-08-15T03:50:24Zcom_123456789_178com_123456789_86com_123456789_67col_123456789_179
Байтелиева, Жанар
2015-06-19T08:19:13Z
2015-06-19T08:19:13Z
2011-12
http://nur.nu.edu.kz/handle/123456789/204
Мақала мазмұны қазақ және түрік тіл білімінде лингвистикалық терминдердің зерттелуін қамтиды. Екі тіл білімінің даму барысы тарихпен байланыстырыла отырып сөз болады.
other
лингвистикалық терминдер
арнаулы лексика
қазақ тіл білімі
түрік тіл білімі
лингвистикалық терминдер сөздігі
Лингвистикалық қазақ және түрік терминдерінің зерттелуі
Article
oai:nur.nu.edu.kz:123456789/2052018-08-15T03:49:31Zcom_123456789_178com_123456789_86com_123456789_67col_123456789_179
Байтелиева, Жанар
2015-06-19T08:24:12Z
2015-06-19T08:24:12Z
2011-09
http://nur.nu.edu.kz/handle/123456789/205
Мақалада қазақ тіліндегі жылқыға қатысты атаулардың пайда болуына әсер еткен уәждемелер айталады. Сонымен тілдік уәжділіктің ерекшеліктері туралы да айтылады.
other
жылқы атаулары
тілдік уәжділік
сөз уәжділігі
морфологиялық уәжділік
семантикалық уәжділік
фонетикалық уәжділік
Жылқыға қатысты атаулардағы тілдік уәжділік
Article
oai:nur.nu.edu.kz:123456789/2062018-08-15T03:49:31Zcom_123456789_178com_123456789_86com_123456789_67col_123456789_179
Байтелиева, Жанар
2015-06-19T08:29:32Z
2015-06-19T08:29:32Z
2011-09
http://nur.nu.edu.kz/handle/123456789/206
Мақалада жылқы малының түр-түсіне байланысты атаулардың тарихи әдебиеттерден бастап бүгінгі күнгі әдебиеттерде қалай беріліп жатқандығы айтылады.
other
түр-түс атаулары
түр-түстің тілдегі көрінісі
жылқы малы
уәжділік
Жылқы малының түр-түсіне байланысты уәжділік
Article
oai:nur.nu.edu.kz:123456789/2072018-08-15T03:49:31Zcom_123456789_178com_123456789_86com_123456789_67col_123456789_179
Байтелиева, Жанар
2015-06-19T08:33:35Z
2015-06-19T08:33:35Z
2014
http://nur.nu.edu.kz/handle/123456789/207
Мақала мазмұны қазақ тіл біліміндегі фразеологиялық тіркестерді тақырыптық-мағыналық топтарға бөлудің теориялық негіздерін қарастырады. Сонымен қатар тақырыптық-мағыналық топтарға бөлудегі әрбір ғалымның ұстанған принциптерінің ерекшеліктерін талдап көрсетеді.
Қазақ тіл білімінде фразеологиялық тіркестер түрлі аспектіде зерттелініп келеді. Соның ішінде этнолингвистикалық сипатын зерттеуде фразеологиялық тіркестерді тақырыптық-мағыналық топтарға бөліп қарастыру маңызды рөл атқарады. Сондықтан мақалада осы тілдік бірліктерді топтастырудың теориялық жағын қарастырған еңбектерге шолу жасалды. Сонымен қатар қазақ тіл білімінде фразеологиялық тіркестерді зерттеген ғалымдардың ғылыми еңбектеріндегі тақырыптық-мағыналық топтарға бөлуде ұстанған принциптері де сөз болды. Мақаладағы негізі ойлар тілді ұлт танымымен тығыз байланыста қарастыруды көздейді. Себебі фразеологиялық тіркестерді тақырыптық-мағыналық жағынан топтастыру, ең алдымен, олардың тілдік қолданыс аясын анықтайды, халықтың тілжасамдық ұзақ процесін, оның мәдени, рухани, әлеуметтік-экономикалық тұрмыс-тіршілігінің белгілі бір шамада елеулі деген аспектілерін көрсетеді.
other
фразеологиялық тіркестер
тақырыптық-мағыналық топтар
уәждеме
экстралингвистикалық факторлар
Жылқы малына қатысты атаулардың этимологиялық негіздері
Article
oai:nur.nu.edu.kz:123456789/2122018-01-29T21:01:30Zcom_123456789_100com_123456789_67col_123456789_211
2015-06-19T09:46:05Z
2015-06-19T09:46:05Z
2015
http://nur.nu.edu.kz/handle/123456789/212
other
АЛЖИР
Қасірет қақпасы
ГУЛАГ
Алаш
"АЛЖИР" - дің әйгілі есімдері"
Presentation
oai:nur.nu.edu.kz:123456789/2132018-08-15T03:49:32Zcom_123456789_100com_123456789_67col_123456789_211
Shamatov, Duishon
2015-06-19T09:52:07Z
2015-06-19T09:52:07Z
2015
http://nur.nu.edu.kz/handle/123456789/213
Poem of Kyz-Jibek a manuscript of 101 pages hand-written by a Kazakh political prisoner of KARLAG in Karaganda during the Stalin's period.
other
Kyz-Jibek
Poem of Kyz-Jibek
KARLAG
Küzöbay Kuranov
Ashimkhan Zhampeisov
Қыз Жібек
Return of Kyz-Jibek to glorify friendship and love
Presentation
oai:nur.nu.edu.kz:123456789/2402021-02-05T10:25:48Zcom_123456789_100com_123456789_67col_123456789_925
Sarinzhipov (Саринжипов), Aslan (Аслан)
2015-07-02T05:13:57Z
2015-07-02T05:13:57Z
2013
http://nur.nu.edu.kz/handle/123456789/240
Kazakhstan's higher education system is based on the Soviet governance structure, limited academic freedom and no autonomy from the state. In such a system faculties are contract employees delivering predesigned courses with no incentive to bring new ideas and methods. But employers and the general public are concerned with the mismatch between market demand and curricula of universities. Qualitative research based on two case studies collected evidence on the opportunities for faculty to influence academic affairs of the two most prominent research universities in Kazakhstan. The study gave a detailed picture of state controls, hierarchical structures and limited role of faculty at the higher education institutions under investigation. The national universities of Kazakhstan were also compared with the University of West Florida, a public research university of similar size which is based on academic freedom, shared governance and faculty authority over academic matters. Conceptual framework for the analysis is based on the theory that university governance differs from other organizations in its involvement of faculty in decision making on academic affairs. The power is shared with faculty because of their recognized knowledge and authority in teaching and research in their particular professional fields. ^ The study identified that the national universities in Kazakhstan are established regulated and run like government organizations with a hierarchical structure. The existing centralized and stricter controlled environment results in frustrated and demotivated faculty who are not able to produce good quality teaching and research. Universities are required to produce similar academic programs and courses and offer a limited number of majors approved by the inter-ministerial committee. Structures of degree programs are set according to State Standards and contain certain share of mandatory courses which are provided by the Ministry. The universities are managed by the rectors who have wide powers especially in hiring and promotion of faculty as well as on other academic matters. ^ The research identified a number of shortcomings and mismatches with international theory and international best practice. If national universities are to develop they have to be allowed to compete and have freedom to innovate. The national universities need the governing boards to be introduced. Increasing faculty participation will be central to promoting key values of higher education such as academic freedom, autonomy and transparency. Empowering faculty will contribute to their greater responsibility and engagement in developing higher education institutions and their core functions of teaching, research and community service.
en
education
Higher Education Administration
Opportunities for faculty to influence academic matters at Kazakh National University and Eurasian National University
Thesis of the employee
oai:nur.nu.edu.kz:123456789/3212018-08-15T03:49:35Zcom_123456789_104com_123456789_67col_123456789_320
Bulanin, D.
2015-09-07T09:35:23Z
2015-09-07T09:35:23Z
2015
http://nur.nu.edu.kz/handle/123456789/321
The cancer stem cell theory suggests that tumors grow like normal tissues of the body, with stem cells at the starting point of an organized system that produces new cells to make a tissue grow. According to this idea, tumors contain:
Cancer stem cells that divide and feed tumour growth. These cells can self-renew (copy themselves) extensively, and also produce more mature cells called transit amplifying cells-...
en
colorectal cancer
anatomy of colon
stages of colorectal cancer
anatomy of the intestine
Intestinal crypt organization
enterocytes
goblet cells
panneth cells
cancer treatment
Research Subject Categories::MEDICINE
Cancer stem cells in colorectal cancer
Presentation
oai:nur.nu.edu.kz:123456789/3222018-08-15T03:49:33Zcom_123456789_104com_123456789_67col_123456789_320
Trenozhnikova, Lyudmila
Azizan, Azliyati
2015-09-09T06:25:18Z
2015-09-09T06:25:18Z
2015-04-17
http://nur.nu.edu.kz/handle/123456789/322
Bacteria in the order Actinomycetales account for 45% of the bioactive microbial metabolites discovered. These organisms have played a central role in the development of the modern pharmaceutical industry. The search for novel antibiotics for use in medicine – important aspect of soil microbial diversity.
en
antibiotics
resistance
antimicrobial drugs
bacteria
micromonospora
streptomyces
Research Subject Categories::MEDICINE
natural products
Extremophiles from unique ecosystems of Kazakhstan as potential producers of novel antibiotics
Presentation
oai:nur.nu.edu.kz:123456789/3232018-08-15T03:49:33Zcom_123456789_104com_123456789_67col_123456789_320
Pignatelli, M.
2015-09-09T06:39:24Z
2015-09-09T06:39:24Z
2015
http://nur.nu.edu.kz/handle/123456789/323
Role of Pathology and Pathologists in Precision Medicine: Customisation of Healthcare,
Targeting drugs for each unique genetic profile.
Key requirements:
- Molecular diagnostics
- Drug development programme
- High quality Pathology including good tissue
sample history
en
pathology
precision medicine
pathological anatomy
cellular pathology
Robin Warren
modern medicine
discovery of helicobacter pylori
morphological observation
pathological grade and prognosis
colon cancer
prostate cancer
lung cancer
ovarian cancer
bladder cancer
Research Subject Categories::MEDICINE
molecular diagnostics
drug development programme
The new face of pathology in precision medicine
Presentation
oai:nur.nu.edu.kz:123456789/3242018-08-15T03:49:32Zcom_123456789_104com_123456789_67col_123456789_320
Frossard, Philippe
2015-09-09T06:51:54Z
2015-09-09T06:51:54Z
2015-03-13
http://nur.nu.edu.kz/handle/123456789/324
Why does global cardiovascular health matter?
Pakistan Risk Of Myocardial Infarction Study. This project aims at identifying the genetic, biomarker and lifestyle determinants of acute myocardial infarction in the Pakistani population.--
en
CVD’s in South Asians
Pakistan-based studies
genetic
biomarker and lifestyle investigations
cardiovascular health
cardiovascular disease
CVD mortality
cerebrovascular events
Pakistan
anthropometry
consanguinity
gene disease
genetic factors
Intermediate biological pathways
Unraveling the molecular mechanisms of CVD’s: the PROMIS model
Presentation
oai:nur.nu.edu.kz:123456789/3252018-08-15T03:49:32Zcom_123456789_104com_123456789_67col_123456789_320
Askarova, Sholpan
2015-09-09T08:52:18Z
2015-09-09T08:52:18Z
2015
http://nur.nu.edu.kz/handle/123456789/325
Alzheimer’s disease is the most common form of dementia in the elderly, which accounts up to 80 % of all cases.
•Clinical manifestation of the disease includes cognitive impairments such as attention deficit, spatial disorientation, speech disorders, and progressive loss of memory.
•In the late stage of Alzheimer's, people generally lose the ability to communicate coherently, experience a decline in physical abilities and require total assistance with personal care.
•Those with Alzheimer's live an average of eight years after their symptoms become noticeable to others, but survival can range from four to 20 years, depending on age and other health conditions.--
en
Alzheimer’s disease
pathophysiology of AD
Amyloid Cascade Hypothesis
amyloidogenic processing
Dysfunction of Cerebral Endothelium in Alzheimer's disease
Presentation
oai:nur.nu.edu.kz:123456789/3352018-08-15T03:50:24Zcom_123456789_100com_123456789_67col_123456789_334
Sagintayeva, A.
Bridges, David
McLaughlin, Colleen
Mehisto, Peeter
Drummond, Mary Jane
Ayubayeva, Nazipa
Kishkentayeva, Marina
Kulakhmetova, Anel
Sadvakassova, Meruyert
Gasskov, Vladimir
Ganimurat, Nurzhan
Canning, Mary
Finney, Joni
Jones, Dennis
McGuinness, Aims
Harvey, Darcie
Bilyalov, Darkhan
Sagyndykova, Zhanna
2015-09-14T05:25:23Z
2015-09-14T05:25:23Z
2014
978-601-7417-35-2
http://nur.nu.edu.kz/handle/123456789/335
The final report on the first phase (2013) of the “Development of the strategic directions for education reform in Kazakh- stan for 2015-2020” project was implemented by the Graduate School of Education at Nazarbayev University on behalf of the Ministry of Education and Science of the Republic of Kazakhstan. The purpose of this research is to conduct a diagnosis of the education system of the Republic of Kazakhstan in order to identify the strengths and weaknesses of the educational system and the subsequent identification of areas for further modernization at each level.
en
education reform in Kazakhstan
educational system
Higher education
education
diagnostic report
DEVELOPMENT OF STRATEGIC DIRECTIONS FOR EDUCATION REFORMS IN KAZAKHSTAN FOR 2015 – 2020
Other
oai:nur.nu.edu.kz:123456789/3362018-08-15T03:49:32Zcom_123456789_100com_123456789_67col_123456789_334
Сагинтаева, Аида
Бриджес, Дэвид
МакЛафлин, Коллин
Мехисто, Питер
Драммонд, Мери-Джейн
Аюбаева, Назипа
Кишкентаева, Марина
Кулахметова, Анель
Садвакасова, Меруерт
Гаськов, Владимир
Ганимурат, Нуржан
Кэннинг, Мэри
Фини, Джонни
Джонс, Дэннис
МакГиннес, Эймс
Харви, Дарси
Билялов, Дархан
Сагындыкова, Жанна
2015-09-14T05:39:58Z
2015-09-14T05:39:58Z
2014
978-601-7417-35-2
http://nur.nu.edu.kz/handle/123456789/336
Итоговый отчет по первому этапу проекта (2013 г.) «Разработка стратегических направлений реформирования образования Республики Казахстан на 2015-2020гг.» был реализован Высшей школой образования Назарбаев Университета по поручению Министерства образования и науки Республики Казахстан. Целью данной научной работы является проведение диагностики системы образования Республики Казахстан с целью выявления сильных и слабых сторон образовательной системы и последующее определение направлений для дальнейшей модернизации на каждом из уровней.
other
диагностика системы образования РК
диагностический отчет
разработка стратегических направлений
образование
дошкольное образование
национальные стандарты
трехъязычное образование
высшее образование и наука
Назарбаев Университет
РАЗРАБОТКА СТРАТЕГИЧЕСКИХ НАПРАВЛЕНИЙ РЕФОРМИРОВАНИЯ ОБРАЗОВАНИЯ РЕСПУБЛИКИ КАЗАХСТАН на 2015 – 2020 гг.
Other
oai:nur.nu.edu.kz:123456789/3372018-08-15T03:49:33Zcom_123456789_100com_123456789_67col_123456789_334
Сағынтаева, Аида
Бриджес, Дэвид
Кэннинг, Мэри
2015-09-14T06:27:37Z
2015-09-14T06:27:37Z
2014
978-601-7417-36-9
http://nur.nu.edu.kz/handle/123456789/337
«Қазақстан Республикасының 2015-2020 жылдарға арналған білім беру жүйесін реформалаудағы стратегиялық бағыттарды әзірлеу» жобасының бірінші кезең бойынша (2013 ж.) қорытынды есебі Қазақстан Республикасы Білім және ғылым министрлігінің тапсырысы бойынша Назарбаев Университеті Жоғары білім беру мектебімен іске асырылды. Аталмыш ғылыми жұмыстың негізгі мақсаты - білім беру жүйесінің мықты және осал тұстарын анықтау, сонымен қатар кейіннен білім беру саласының барлық деңгейлерін модернизациялау үшін Қазақстан Республикасы білім беру жүйесінің диагностикасын өткізу.
other
білім беру жүйесін реформалау
ДИАГНОСТИКАЛЫҚ ЕСЕП
Жоғары білім беру мектебі
жоғары білім
ҚАЗАҚСТАН РЕСПУБЛИКАСЫНДА 2015–2020 жж. БІЛІМ БЕРУДІ РЕФОРМАЛАУДЫҢ СТРАТЕГИЯЛЫҚ БАҒЫТТАРЫН ЖҮЗЕГЕ АСЫРУ
Other
oai:nur.nu.edu.kz:123456789/3382018-08-15T03:49:33Zcom_123456789_104com_123456789_67col_123456789_320
Jasani, Bharat
2015-09-25T09:19:01Z
2015-09-25T09:19:01Z
2015-09
http://nur.nu.edu.kz/handle/123456789/338
Reflections on the past:
Previous home and institution
Path to a clinical academic career in pathology
Role of a pathologist in diagnostic medicine
Cancer biomarking:
Role in diagnostic pathology
Quality assurance
Conclusion & Discussion
en
diagnostic medicine
medicine
cancer biomarking
cancer
diagnostic pathology
pathology
Research Subject Categories::MEDICINE
The Role of Pathologist in Quality Assurance of Cancer Biomarking
Presentation
oai:nur.nu.edu.kz:123456789/3392018-08-15T03:49:33Zcom_123456789_104com_123456789_67col_123456789_320
McLoone, Pauline
2015-09-25T09:34:24Z
2015-09-25T09:34:24Z
2015
http://nur.nu.edu.kz/handle/123456789/339
•Introduction
•Antimicrobial properties of honey in relation to skin disease
•Immunomodulatory properties of honey
•Anti-carcinogenic properties of honey
•Evidence for the efficacy of honey in the treatment of skin disease
en
honey
disorders of the skin
antimicrobial properties of honey
skin disease
immunomodulatory properties of honey
anti-carcinogenic properties of honey
eczema
psoriasis
skin cancers
staphylococcus
Research Subject Categories::MEDICINE
Honey: a therapeutic agent for disorders of the skin
Presentation
oai:nur.nu.edu.kz:123456789/3402018-08-15T03:49:32Zcom_123456789_100com_123456789_67col_123456789_334
Niyozov, Sarfaroz
Shamatov, Duishon
2015-10-13T04:19:46Z
2015-10-13T04:19:46Z
2006
http://nur.nu.edu.kz/handle/123456789/340
The paper discusses the effects of the collapse of the Soviet Union on teachers'
life and work in Badakhshan and Osh provinces of Tajikistan and Kyrgyzstan.
Challenging some of the assumptions of the Soviet studies about the interaction
between teaching and other sources of moneymaking by teachers, the paper illus
trates continuities and changes in the pre -Soviet, Soviet and post-Soviet times in
terms of role, nature, forms, and ethics of trading and commercial activities in the
life of the teachers in the two countries. The paper draws from the two ethnographic
case studies carried out in Tajikistan and Kyrgyzstan between 1999 and
2005. The drastic actual changes in the status and work of the teachers in post
Soviet Central Asia has presented teachers with tough choices. One of such
choices was whether to become involved in trading and commerce. Teachers'
experience of trading and commercialisation has been contradictory: necessary,
possible, rewarding; yet challenging and often disgusting and contrary to the very
morality of the teaching profession. The teachers' life and work serves as
windows to the larger issues that have both local and global ramifications. The
challenges teachers face in the paper speak to basic issues of human experience:
dignity,j ustice, hope, equity, care and humanity. The paper's major argument is
that while teachers are increasingly gaining from their involvement in trading, it
is the societies that are losing, both by loss of the best teachers and by the
implications of trading and commercial activities on the education systems in
Kyrgyzstan and Tajikistan. The policy makers must make decisions about how
teachers could be provided with conditions that enable them to focus on the major
priority of their work for the benefit of the future generations of Central Asia.
en
teaching
rading
Central Asia
corruption
post-Soviet education
Research Subject Categories::SOCIAL SCIENCES::Social sciences::Education
Trading or teaching: dilemmas of everyday life economy in Central Asia
Article
oai:nur.nu.edu.kz:123456789/3412018-08-15T03:49:32Zcom_123456789_100com_123456789_67col_123456789_334
Shamatov, Duishon
2015-10-13T05:06:03Z
2015-10-13T05:06:03Z
2012
1056–4934 (print)/1944–7086 (online)
http://nur.nu.edu.kz/handle/123456789/341
In Kyrgyzstan, the breakup of the USSR raised many issues related to
equity and fairness in education, one of which is the distribution of public
funds to support scholarship admissions to higher education institutions.
After 1992, public institutions could begin to charge tuition fees, but as
a legacy of the USSR, Kyrgyzstan continues providing “budget-funded
places” (public scholarships) for higher education study. In recent years,
the number of these scholarships has been shrinking, resulting in increased
competition for budget-funded places, and unfortunately, their distribution
has been unfair and discriminatory against students from remote regions
and poorer families. To address these issues, the merit-based National
Scholarship Test (NST) was introduced in 2002 to identify the most deserving
youth, irrespective of where they live and their backgrounds.
Moreover, as a crucial part of the test implementation, quota categories
have been introduced to ensure the proportional representation of youth
from various geographic backgrounds at institutions of higher education.
In the years since its introduction the NST has achieved both successes
and setbacks. Generally considered a huge step forward, the NST has
been able to impact equity in education on a broad scale. However, challenges
still remain.
en
European education
Kyrgyz education in the Soviet era
Kyrgyz education
Soviet Union
national scholarship
post-Soviet Kyrgyzstan
national scholarship testing
the impact of standardized testing
Research Subject Categories::SOCIAL SCIENCES::Social sciences::Education
The impact of standardized testing on university entrance issues in Kyrgyzstan
Article
oai:nur.nu.edu.kz:123456789/3422018-08-15T03:49:33Zcom_123456789_100com_123456789_67col_123456789_334
Ashraf, Dilshad
Khaki, Jan-e-Alam
Shamatov, Duishon
Tajik, Mir Afzal
Vazir, Nilofar
2015-10-13T05:43:04Z
2015-10-13T05:43:04Z
2005
http://nur.nu.edu.kz/handle/123456789/342
Teacher education in developing countries faces great challenges attributable to economic
constraints, including shrinking resources, the low status of teachers—exacerbated
by declining incentives—and an entirely theoretical approach in teacher training
programs. These challenges are further intensified by variations in the trainees’
cultural, regional, and religious backgrounds and by the lack of collaboration between
different education sectors. In this context, the Aga Khan University Institute for Educational
Development (AKU-IED) in Karachi, Pakistan, is attempting to provide
contextually appropriate, effective teacher education programs for Pakistan and other
developing countries. This article draws on the authors’ personal experiences in the
teacher education programs at AKU-IED and on studies that examine the impact of
these programs on participants. Several studies show that teacher education transforms
teachers’ beliefs and practices if accomplished through more effective approaches.
The article discusses how teacher education programs are conceptualized
and implemented in the multicultural context of AKU-IED, where the course participants
come from various developing countries and diverse backgrounds.
en
professional development of teachers
reconceptualization of teaching and learning
positive interdependence
Aga Khan University Institute for Educational Development
reflective practice
Research Subject Categories::SOCIAL SCIENCES::Social sciences::Education
Reconceptualization of teacher education experiences from the context of a multicultural developing country
Article
oai:nur.nu.edu.kz:123456789/4042018-08-15T03:49:35Zcom_123456789_104com_123456789_67col_123456789_320
Ali, Syed
2015-10-15T08:58:49Z
2015-10-15T08:58:49Z
2015
http://nur.nu.edu.kz/handle/123456789/404
en
Research Subject Categories::MEDICINE
epidemiology
genome
pathogenesis
treatment
HCV replicon
HCV inhibitors from bench to bedside
Presentation
oai:nur.nu.edu.kz:123456789/8012018-08-15T03:49:45Zcom_123456789_528com_123456789_95com_123456789_67col_123456789_530
Pelizzo, Riccardo
Nwokora, Zim
2015-11-24T04:03:33Z
2015-11-24T04:03:33Z
2015
Riccardo Pelizzo and Zim Nwokora. "The political consequences of party system change" Politics and Policy 43.4 (2015): 453-473. DOI: 10.1111/polp.12124
http://nur.nu.edu.kz/handle/123456789/801
This article engages one of the important gaps in the literature on party system effects: the consequences of party system change. We discuss how existing empirical approaches to party system change do not actually capture the changeability of patterns of party competition, which is the most direct understanding of the term “party system.” We propose a measure that does exactly this: the index of fluidity. Applying this measure to countries in South East Asia, we show that party system change is associated with harmful effects,including lower foreign direct investment and deterioration of the rule of law.
en
party systems
political systems
comparative politics
measuring party system change
Index of fluidity
party system effects
Interparty competition
cross-national studies
party system stability
Instability
public policy
foreign investment
rule of law
Research Subject Categories::SOCIAL SCIENCES::Social sciences::Political science
The political consequences of party system change
Article
oai:nur.nu.edu.kz:123456789/8022018-08-15T03:49:45Zcom_123456789_528com_123456789_95com_123456789_67col_123456789_530
Pelizzo, Riccardo
Nwokora, Zim
Kinyondo, Abel
2015-11-24T04:28:11Z
2015-11-24T04:28:11Z
2015
Riccardo Pelizzo, Abel Kinyondo, and Zim Nwokora. "The costs of party system change: the case of Tanzania" African Politics and Policy 1.3 (2015): 1-11.
http://nur.nu.edu.kz/handle/123456789/802
Pelizzo, Kinyondo and Nwokora argue that party system changes and increases in party system changeability have generally been associated with a worsening democratic quality.
en
parties
party systems
democracy
Tanzania
Research Subject Categories::SOCIAL SCIENCES::Social sciences::Political science
The costs of party system change: the case of Tanzania
Article
oai:nur.nu.edu.kz:123456789/8032018-08-15T03:49:45Zcom_123456789_528com_123456789_95com_123456789_67col_123456789_530
Pelizzo, Riccardo
Omer, Baris
2015-11-24T05:45:30Z
2015-11-24T05:45:30Z
2015
Riccardo Pelizzo and Omer F. Baris. "Governance, business environment, and foreign direct investments" African Politics and Policy 1.2 (2015): 1-23.
http://nur.nu.edu.kz/handle/123456789/803
In this paper we investigate the relationship between the quality of governance, the business environment and foreign direct investments. Looking at 49 countries in Africa, we present evidence supporting the claim that the quality of governance does affect the stability of policies and the quality of the business environment. However, our data analysis also reveals that neither the quality of governance nor the quality of the business environment have any impact, at least in Sub-Saharan Africa on the level of FDI.
en
quality of governance
the business environment
governance
Governance, business environment and foreign direct investments
Article
oai:nur.nu.edu.kz:123456789/8042018-08-15T03:49:45Zcom_123456789_528com_123456789_95com_123456789_67col_123456789_530
Pelizzo, Riccardo
Kinyondo, Abel
2015-11-24T05:58:24Z
2015-11-24T05:58:24Z
2015
Riccardo Pelizzo and Abel Kinyondo. "Tourism and employment: the case of Togo" African Politics and Policy 1.1 (2015): 18-29.
http://nur.nu.edu.kz/handle/123456789/804
This paper sets to investigate whether and to what extent the development of tourism sector in Togo is associated with and possibly responsible for economic growth, employment creation and generation of wealth in the country. Results from this paper shows that the development of tourism in Togo has created both business and employment opportunities and that the expansion of the workforce in this sector has been associated with, and to some extent it has been responsible for, a decline in the unemployment rate in the country. In light of these findings, we recommend that the Togolese government should ensure that the tourism sector is strategically built in such a way that it forms an integral part of all of its development plans and that more serious efforts are invested in marketing the sector which is currently largely underutilized.
en
tourism sector
employment
tourism
Tourism and employment: the case of Togo
Article
oai:nur.nu.edu.kz:123456789/8052018-08-15T03:49:45Zcom_123456789_528com_123456789_95com_123456789_67col_123456789_531
Pelizzo, Riccardo
2015-11-24T09:35:43Z
2015-11-24T09:35:43Z
2013-11
Riccardo Pelizzo. Government accountability and legislative oversight. , 2013.
http://nur.nu.edu.kz/handle/123456789/805
This handbook summarizes the findings and implications of recent research on
legislative oversight in countries with presidential forms of government. It also
updates and revises good practice in parliamentary systems. The full research
findings and their implications can be found in Riccardo Pelizzo and Frederick
Stapenhurst Government Accountability and Legislative Oversight.
en
corruption
legislative oversight
government accountability
Government accountability and legislative oversight
Book
oai:nur.nu.edu.kz:123456789/8072021-02-05T10:25:49Zcom_123456789_527com_123456789_95com_123456789_67col_123456789_806
Pelizzo, Riccardo
2015-11-24T09:46:22Z
2015-11-24T09:46:22Z
2008-01
Riccardo Pelizzo. Cartel parties and cartel party systems. VDM Verlag, 2008.
http://nur.nu.edu.kz/handle/123456789/807
The transformation of Western European Party Systems was associated with the emergence of a new model of party organization: the cartel party.The cartel party differs from previous party models because it is increasingly less an agent of society, has interests on its own, depends on state subsidies and struggles to preserve the conditions under whihc it prospers by distorting electoral competition. Through such a distortion the cartel of parties resembles the behavior of oligopolistic firms. The purpose of this book is to investigate whether and to what extent patterns of inter-party competition resemble the functioning of oligopolistic markets.The results of our comparative analysis reveal that there is a growing gap between voters' demands and party system's political supply. In addition to arguing the implications of these findings for the theory of responsible party government, this books shows that the growing gap between voters' demands and party systems' supply creates the condition for the rise of the parties of the New Extreme Right
en
party systems
Cartel parties
Cartel parties and cartel party systems
Thesis of the employee
oai:nur.nu.edu.kz:123456789/8082018-08-15T03:49:45Zcom_123456789_527com_123456789_95com_123456789_67col_123456789_800
Pelizzo, Riccardo
Stapenhurst, Rick
2015-11-24T09:55:43Z
2015-11-24T09:55:43Z
2008
http://nur.nu.edu.kz/handle/123456789/808
This chapter discusses the difference between codes of ethics and codes of conduct, their role, their function and their distribution. The chapter also pays some attention to what makes codes of conduct most effective.
en
codes of ethics
codes of conduct
legislative ethics
Legislative ethics and codes of conduct
Book
oai:nur.nu.edu.kz:123456789/8092018-08-15T03:49:45Zcom_123456789_527com_123456789_95com_123456789_67col_123456789_800
Pelizzo, Riccardo
2015-11-24T10:02:40Z
2015-11-24T10:02:40Z
2006
Riccardo Pelizzo. "Political parties" The role of parliament n curbing corruption. Ed. F. Stapenhurst, N. Johnston and R. Pelizzo. washington dc: world bank, 2006. 173-182.
http://nur.nu.edu.kz/handle/123456789/809
Building on the work by Huntington (1968) and Panebianco (1983) this chapters discusses the relationship between corruption and the inadequate institutionalization of political parties.
en
corruption
inadequate institutionalization
political parties
Research Subject Categories::SOCIAL SCIENCES::Social sciences::Political science
Political parties
Book chapter
oai:nur.nu.edu.kz:123456789/8102018-08-15T03:49:36Zcom_123456789_527com_123456789_95com_123456789_67col_123456789_799
Pelizzo, Riccardo
Kinyondo, Abel
2015-11-25T10:19:29Z
2015-11-25T10:19:29Z
2014
Rccardo Pelizzo and Abel Kinyondo. 2014. "Public Accounts Committees in Eastern Africa. A comparative analysis"
http://nur.nu.edu.kz/handle/123456789/810
Properly functioning Public Accounts Committees (PACs) are essential for promoting good governance, preventing misallocation of resources and curbing corruption. The purpose of the present paper is to analyze the organization, powers and the performance of East Africa’s PACs so as to understand what they do, what makes them work well and what could make them work better. The analysis reveals that the Tanzania’s PAC is the most active in the region because while it has fewer resources at its disposal than its Eastern African counterparts, it makes a more efficient use of the available resources as indicated by the fact that the Tanzanian Pac was able to carry out more oversight activities than the other PACs operating in the region in spite of having fewer resources. This evidence sustains the claim that legislators’ political will is the single most important determinant of effective oversight. On the basis of the evidence presented in the paper, we formulate two policy recommendations: that in order to secure a more
effective PAC performance, international organizations should pay greater attention to ensuring that legislators have the will to be effective overseers and that the Tanzania’s PAC needs to be more adequately staffed and resourced.
en
public accounts committees
East Africa
Tanzania
Public accounts committees in Eastern Africa: a comparative analysis
Article
oai:nur.nu.edu.kz:123456789/8112018-08-15T03:49:39Zcom_123456789_528com_123456789_95com_123456789_67col_123456789_530
Pelizzo, Riccardo
Bandyopadhyay, Sruti
2015-11-25T10:29:06Z
2015-11-25T10:29:06Z
2013
Riccardo Pelizzo and Sruti Bandyopadhyay. 2013. "Organization, mandate, performance: PACs in the Asian region"
http://nur.nu.edu.kz/handle/123456789/811
The paper is divided in four parts. Part One provides some information concerning the size, the partisan affiliation of the Chairpersons, the representation of opposition parties and the size of the support staff of the Asian PACs. Part two discusses the way in which PACs are set up, the dispositions under which they operate and the scope of their mandate. Part Three discusses the amount of activities carried out by PACs in the Asian region, while in the final part we draw some conclusions.
en
PAC
mandate
performance
organization
Organization, mandate, performance: PACs in the Asian region
Article
oai:nur.nu.edu.kz:123456789/8122018-08-15T03:49:43Zcom_123456789_527com_123456789_95com_123456789_67col_123456789_799
Pelizzo, Riccardo
2015-11-25T10:35:09Z
2015-11-25T10:35:09Z
2013
Riccardo Pelizzo. 2013. "Public Accounts Committees in the Pacific Region" public account, legislative oversight, governance
http://nur.nu.edu.kz/handle/123456789/812
the paper analyzes the organization, the powers, the functioning and the performance of Public Account Committees in the Pacific region. In doing so the paper highlights some of the factors have contributed to making PACs from the Pacific island states work effectively
en
performance of Public Account Committees in the Pacific region
public account committees
Pacific Region
Public accounts committees in the Pacific region
Article
oai:nur.nu.edu.kz:123456789/8132018-08-15T03:49:43Zcom_123456789_528com_123456789_95com_123456789_67col_123456789_530
Pelizzo, Riccardo
Kindra, Gurprit
2015-11-25T10:40:05Z
2015-11-25T10:40:05Z
2012
Riccardo Pelizzo and Gurprit Kindra. 2012. "Party System Fragmentation and PAC Performance: the Case of India"
http://nur.nu.edu.kz/handle/123456789/813
While the political consequences of party system fragmentation have extensively been discussed in the literature, little to no attention has been paid to whether the fragmentation of the party system affects the performance of public accounts committees. The purpose of this paper is to fill this gap by investigating the relationship between the fragmentation of the Indian party system on the one hand and the performance of the Indian public account committee. The evidence presented in the paper sustains the claim that such relationship is curvilinear which means that rising levels of fragmentation are beneficial to PAC performance up to a certain point, while they prevent its effective performance when they exceed a critical value.
en
Indian party
party systems
parties
Party system fragmentation
Research Subject Categories::SOCIAL SCIENCES::Social sciences::Political science
Party system fragmentation and PAC performance: the Case of India
Article
oai:nur.nu.edu.kz:123456789/8142018-08-15T03:49:43Zcom_123456789_528com_123456789_95com_123456789_67col_123456789_530
Pelizzo, Riccardo
2015-11-25T10:44:45Z
2015-11-25T10:44:45Z
2012-01
Riccardo Pelizzo. 2012. "A new index of legislative oversight"
http://nur.nu.edu.kz/handle/123456789/814
The purpose of this paper is to present a new index of legislative oversight. Building on the work by Stapenhurst (2011), who argued that a proper index of legislative oversight capacity should reflect not only legislatures’ internal oversight capacity but also the impact of contextual factors, we devise and propose a modified version of the Stapenhurst. The results of the empirical analyses presented in the paper sustain the claim that when properly operationalized and measured, legislative oversight capacity is a good predictor of legislative oversight effectiveness and other policy relevant results.
en
index of legislative oversight
Research Subject Categories::SOCIAL SCIENCES::Social sciences::Political science
A new index of legislative oversight
Article
oai:nur.nu.edu.kz:123456789/8162018-08-15T03:49:43Zcom_123456789_528com_123456789_95com_123456789_67col_123456789_815
Pelizzo, Riccardo
2015-11-25T10:49:29Z
2015-11-25T10:49:29Z
2015-04
Riccardo Pelizzo. "Measures of Corruption" GSPP. Astana, Kazakhstan. Apr. 2015
http://nur.nu.edu.kz/handle/123456789/816
The presentation provides an overview of the measures of corruption that can be used to track corruption across countries and over time.
en
measures of corruption
corruption
comparative politics
Research Subject Categories::SOCIAL SCIENCES::Social sciences::Political science
Measures of corruption
Presentation
oai:nur.nu.edu.kz:123456789/8172018-08-15T03:49:45Zcom_123456789_528com_123456789_95com_123456789_67col_123456789_815
Pelizzo, Riccardo
2015-11-25T11:00:49Z
2015-11-25T11:00:49Z
2013-12
riccardo pelizzo. "PACs and their functional equivalents in South East Asia." Dec. 2013.
http://nur.nu.edu.kz/handle/123456789/817
In this presentation, we present the preliinary results of an analysis of the tools and the committees in charge of performing budgetary and financial oversight in south East Asian countries
en
south East Asian countries
budgetary
PACs and their functional equivalents in South East Asia.
Article
oai:nur.nu.edu.kz:123456789/8182018-08-15T03:49:45Zcom_123456789_528com_123456789_95com_123456789_67col_123456789_815
Pelizzo, Riccardo
2015-11-25T11:16:05Z
2015-11-25T11:16:05Z
2013-11
Riccardo Pelizzo. "PACs, Presidential Systems, and Good Governance" NAPAC. Abuja, Nigeria. Nov. 2013.
http://nur.nu.edu.kz/handle/123456789/818
en
presidential systems
Research Subject Categories::SOCIAL SCIENCES::Social sciences::Political science
PACs, Presidential Systems, and Good Governance
Presentation
oai:nur.nu.edu.kz:123456789/8332018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_821
Duysebaev, B.
Abramov, A.
Berstenev, S.
Ryspanov, N.
Sokolov, A.Y.
Shkolnik, V.
Umirov, N.
Bakenov, Zhumabay
2015-12-02T07:36:18Z
2015-12-02T07:36:18Z
2014
Duysebaev B., Abramov A., Berstenev S., Ryspanov N., Sokolov A.Y., Shkolnik V., Umirov N., Bakenov Z., 2014, Investigation of using sulfur-containing gases in low-temperature fuel cell at sulfuric acid production site, Eurasian Chemico-Technological Journal 16
http://nur.nu.edu.kz/handle/123456789/833
The possibility and effectiveness of using sulfur dioxide and hydrogen sulfide as the fuel in lowtemperature
fuel cells at the sulfuric acid production site has been investigated. A fuel cell has been designed
and constructed using palladium as a catalyst, which enables conversion of the energy of oxidation of sulfur
dioxide and hydrogen sulfide to the electric energy. The experimental data showed that the use of hydrogen
sulfide and sulfur dioxide as a fuel allows achieving the power of 1.0 and 0.5 mW, respectively. The
comparative studies with the use of hydrogen in the same fuel cell resulted in the power of about 2.0 mW,
i.e. the use of hydrogen sulfide delivers a performance comparable with that of the hydrogen. The processes
of oxidizing of the sulfur containing gases are used in our company in production of sulfuric acid. Oxidation
of these gases conducted using the conventional technological processes. The use of these processes to
produce energy as a byproduct could be an attractive way to reduce the energy consumption of the whole
process. Considering the relatively high power obtained in this work for the sulfur containing gases fed fuel
cells, the substitution of conventional oxidation of sulfur containing gases in this technological chain by the
fuel cell oxidation, and by-producing the electric energy, could be very profitable for the energy efficiency
enhancement of the main production process. In the future work, the design and development of fuel cell
catalysts and membranes to enhance the performances of sulfur containing fuel cells will be significant.
en
hydrogen sulfide
sulfur dioxide
technological processes
energy consumption
fuel cell oxidation
electric energy
Investigation of using sulfur-containing gases in low-temperature fuel cell at sulfuric acid production site
Article
oai:nur.nu.edu.kz:123456789/8292018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Zarea, Stefan
Rojas-Solorzano, L.
2015-12-02T04:43:39Z
2015-12-02T04:43:39Z
1997-06-22
http://nur.nu.edu.kz/handle/123456789/829
The main objective of this paper is to present the results of the experimental investigation of a Zarea-type torsional velocity-meter. For this, a torsional meter was designed, built and tested in the laboratory. The current meter consists of an axial rotor with blades fixed to a shaft which is in turn fixed to a rigid hub. The force of the water flow produces a torque which deforms the shaft. The current meter has been statically calibrated, thereby establishing the variational curve of the torsion angle as a function of the applied torque. A laboratory facility has been constructed in which tests were run for water speeds of up 3m/s. The torque measurements were taken by using strain gauges. The methodology and the equipment used for the experimental evaluation are shown. Additionally illustrated are the calibration curves, the analysis of obtained results, some advantages and disadvantages, and the range of application of the torsional current-meter are all discussed.
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics::Mechanical manufacturing engineering
torsional current-meter
mechanical engineering
Torsional current - meter for channels
Article
oai:nur.nu.edu.kz:123456789/8302021-02-05T10:25:51Zcom_123456789_79com_123456789_67col_123456789_822
Rojas-Solorzano, L.
2015-12-02T05:24:16Z
2015-12-02T05:24:16Z
1997-05-10
http://nur.nu.edu.kz/handle/123456789/830
The receptivity and stability of steady non-separated and unsteady separated boundary layers in a two-dimensional airfoil cascade flow is investigated by Direct Numerical Simulation of the time-dependent Navier-stokes and continuity equations. The study includes the effects caused by the introduction of free-steam time-harmonic disturbances. The calculation of the transport, generation and dissipation of Fluctuating Kinetic Energy is introduced as a non-classical technique in the analysis
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
fluid mechanics
Boundary layer receptivity and resonance caused by tuned disturbances within cascade flows
Thesis of the employee
oai:nur.nu.edu.kz:123456789/8312018-08-15T03:49:44Zcom_123456789_79com_123456789_67col_123456789_826
Rojas-Solorzano, L.
2015-12-02T05:57:07Z
2015-12-02T05:57:07Z
1998
http://nur.nu.edu.kz/handle/123456789/831
The generation and early evolution of boundary layer transitional instabilities, named Tollmien-Schlichting (T-S) waves, in airfoil cascade flows are studied. The energy exchange between the mean flow and the flow instabilities is computed by performing Direct Numerical Simulation of the fluid flow governing equations and by calculating the fluctuating kinetic energy (FKE) budget within the separated boundary layer. The driving role of the FKE production in the wavelength modulation process associated to the receptivity phenomenon, i.e., the generation of T-S waves, is demonstrated. The FKE production largely hastens the wavelength modulation around the inflection point of the mean velocity profile across the boundary layer. Above the inflection point, the fluctuating pressure field favors the energy transport and provides the energy necessary to convect the instabilities out of the boundary layer. The evolution of the T-S waves depicts an asymmetric distribution of the production term in the transverse direction, i.e., in the lower half of the boundary layer the mean flow provides energy to the instabilities while the opposite occurs in the upper half
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Tollmien-Schlichting waves
Oscillatory momentum transport in cascade transitional boundary layer flows
Article
oai:nur.nu.edu.kz:123456789/8322018-08-15T03:49:43Zcom_123456789_79com_123456789_67col_123456789_826
Rojas-Solorzano, L.
2015-12-02T06:26:02Z
2015-12-02T06:26:02Z
1998-06-21
Luis R. Rojas-Solorzano, 1998, Effects of external disturbances on the momentum transport in cascade transitional boundary layer flows, http://nur.nu.edu.kz/handle/123456789/832
http://nur.nu.edu.kz/handle/123456789/832
The effects on the boundary layer receptivity in airfoil cascade flow caused by superposed disturbances are studied using an energetic approach. The separated terms in the Fluctuating Kinetic Energy (FKE) budget are calculated. Monotonic time-harmonic disturbances are superposed to the inflow stream using forcing frequencies close to and far from the natural frequency of fluctuation found within the unsteady (supercritical) basic flow. For supercritical regimes, the receptivity is evaluated around the boundary layer separation point, where Tollmien-Schlichting (T-S) waves are naturally generated. For subcritical regimes, the receptivity is explored all over the suction-side of the airfoil since separation does not occur. Within subcritical flows, the superposed perturbation is seen to trigger the generation of T-S-like waves downstream the minimum pressure point only when the forcing frequency is close to n. Within supercritical flows, when the forcing frequency matches n, the FKE budget reflects the energetic interaction between the perturbation and the already existent boundary layer T-S waves
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Fluctuating Kinetic Energy
Effects of external disturbances on the momentum transport in cascade transitional boundary layer flows
Article
oai:nur.nu.edu.kz:123456789/8372018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_821
Zhang, Yongguang
Zhao, Yan
Bakenov, Zhumabay
2015-12-02T08:47:32Z
2015-12-02T08:47:32Z
2014
Zhang Yongguang., Zhao Yan., Bakenov Zhumabay., 2014, A novel lithium/sulfur battery based on sulfur/graphene nanosheet composite cathode and gel polymer electrolyte, Nanoscale Research Letters, doi:10.1186/1556-276X-9-137
http://nur.nu.edu.kz/handle/123456789/837
A novel sulfur/graphene nanosheet (S/GNS) composite was prepared via a simple ball milling of sulfur with
commercial multi-layer graphene nanosheet, followed by a heat treatment. High-resolution transmission and
scanning electronic microscopy observations showed the formation of irregularly interlaced nanosheet-like structure
consisting of graphene with uniform sulfur coating on its surface. The electrochemical properties of the resulting
composite cathode were investigated in a lithium cell with a gel polymer electrolyte (GPE) prepared by trapping
1 mol dm−3 solution of lithium bistrifluoromethanesulfonamide in tetraethylene glycol dimethyl ether in a polymer
matrix composed of poly(vinylidene fluoride-co-hexafluoropropylene)/poly(methylmethacrylate)/silicon dioxide
(PVDF-HFP/PMMA/SiO2). The GPE battery delivered reversible discharge capacities of 809 and 413 mAh g−1 at the
1st and 50th cycles at 0.2C, respectively, along with a high coulombic efficiency over 50 cycles. This performance
enhancement of the cell was attributed to the suppression of the polysulfide shuttle effect by a collective effect of
S/GNS composite cathode and GPE, providing a higher sulfur utilization.
en
graphene nanosheet
lithium/sulfur battery
nanostructured sulfur cathode
gel polymer electrolyte
silicon dioxide
polymer matrix
A novel lithium/sulfur battery based on sulfur/graphene nanosheet composite cathode and gel polymer electrolyte
Article
oai:nur.nu.edu.kz:123456789/8382018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Zarea, S.
Rojas-Solorzano, L.
Kabboul, F.
2015-12-02T08:58:24Z
2015-12-02T08:58:24Z
1999-04-21
Zarea, S., Rojas-Solórzano, Luis Ramon., Kabboul, F., 1999, Run Life Enlargement Methodology for Ball-and-Seat Check Valves Used in Artificial Lift Pumping Units,
http://nur.nu.edu.kz/handle/123456789/838
Experiments are performed to evaluate the leakage vs. pressure drop, wear and fluid properties, in ball-and-seat valves used in pumping units for artificial oil production. The
test facility is constructed to evaluate the operation of several valve sizes, using water, oil and air, subjected to pressure drops up to 5000 psig. Results demonstrated that the currently accepted API vacuum test might be too severe and that more realistic tests may lead to substantial savings in valve replacements. Experimental results in dimensional and
dimensionless form are presented, using a new similitude criterion
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Ball-and-Seat Check Valves
Run Life Enlargement Methodology for Ball-and-Seat Check Valves Used in Artificial Lift Pumping Units
Article
oai:nur.nu.edu.kz:123456789/8392018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Salazar S., Abraham
Rojas-Solorzano, L.
2015-12-02T09:08:50Z
2015-12-02T09:08:50Z
2000-02-14
Salazar S., Abraham, Rojas-Solórzano, Luis Ramon; 2000, Fluid flow hydrodynamic modeling in the passage of an oil artificial lift pumping unit, http://nur.nu.edu.kz/handle/123456789/839
http://nur.nu.edu.kz/handle/123456789/839
The study of the two-phase flow through the standing and traveling valves used in an oil artificial-lift pumping unit is presented. The investigation aimed to determine the effects the
gaseous phase may cause on the pump volumetric efficiency. Data obtained on a specially designed test facility is presented and analyzed as a first step before developing a semi-empirical model to predict the performance of the pump under two-phase flow conditions. Preliminary results, based on one-phase and two-phase runs, demonstrate important features introduced on the pump performance once the gas-phase is included in the process
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
oil artificial-lift pumping unit
Fluid flow hydrodynamic modeling in the passage of an oil artificial lift pumping unit
Article
oai:nur.nu.edu.kz:123456789/8402018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_821
Hara, Toru
Konarov, Aishuak
Mentbayeva, Almagul
Kurmanbayeva, Indira
Bakenov, Zhumabay
2015-12-02T09:27:00Z
2015-12-02T09:27:00Z
2015-05-07
Hara T, Konarov A, Mentbayeva A, Kurmanbayeva I and Bakenov Z (2015) High mass-loading of sulfur-based cathode composites and polysulfides stabilization for rechargeable lithium/sulfur batteries. Front. Energy Res. 3:22. doi: 10.3389/fenrg.2015.00022
http://nur.nu.edu.kz/handle/123456789/840
Although sulfur has a high theoretical gravimetric capacity, 1672 mAh/g, its insulating
nature requires a large amount of conducting additives: this tends to result in a low massloading
of active material (sulfur), and thereby, a lower capacity than expected. Therefore,
an optimal choice of conducting agents and of the method for sulfur/conductingagent
integration is critically important. In this paper, we report that the areal capacity
of 4.9 mAh/cm2 was achieved at sulfur mass loading of 4.1 mg/cm2 by casting sulfur/
polyacrylonitrile/ketjenblack (S/PAN/KB) cathode composite into carbon fiber paper.
This is the highest value among published/reported ones even though it does not contain
expensive nanosized carbon materials such as carbon nanotubes, graphene, or graphene
derivatives, and competitive enough with the conventional LiCoO2-based cathodes (e.g.,
LiCoO2, <20 mg/cm2 corresponding to <2.8 mAh/cm2). Furthermore, the combination
of sulfur/PAN-based composite and PAN-based carbon fiber paper enabled the sulfurbased
composite to be used even in carbonate-based electrolyte solution that many
lithium/sulfur battery researchers avoid the use of it because of severer irreversible active
material loss than in electrolyte solutions without carbonate-based solutions, and even at
the highest mass-loading ever reported (the more sulfur is loaded, the more decomposed
sulfides deposit at an anode surface).
en
lithium
sulfur
battery
mass-loading
polysulfide
High mass-loading of sulfur-based cathode composites and polysulfides stabilization for rechargeable lithium/sulfur batteries
Article
oai:nur.nu.edu.kz:123456789/8412018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Concho, Maria A.
Gasbarri, Sandro
Rojas-Solorzano, L.
2015-12-02T09:33:15Z
2015-12-02T09:33:15Z
2000-02-14
Maria A. Concho, Sandro Gasbarri, Luis R. Rojas-Solórzano; 2000, Numerical simulation of the flow through an intermittent gas lift valve, http://nur.nu.edu.kz/handle/123456789/841
http://nur.nu.edu.kz/handle/123456789/841
The numerical simulation of the flow through a pilot valve used in the oil intermittent gas lift process is presented.The complexity of the non-isothermal compressible flow is modeled by the solution of the Navier-Stokes, Mass Conservation and Energy equations for the compressible flow. Numerical results and analyses pertaining to the flow dynamics
through a 1½-inch pilot valve at an operating condition encountered in typical field operations are presented
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Numerical simulation of the flow
Numerical simulation of the flow through an intermittent gas lift valve
Article
oai:nur.nu.edu.kz:123456789/8422018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Payares, C.
Rojas-Solorzano, L.
Viggiani, P.
2015-12-02T09:55:34Z
2015-12-02T09:55:34Z
2000
C. Payares, L. Rojas-Solórzano, P. Viggiani., 2000, Numerical simulation of the heat penetration in two-plate arc welding, http://nur.nu.edu.kz/handle/123456789/842
http://nur.nu.edu.kz/handle/123456789/842
A mathematical model and numerical simulation of the three-dimensional and transient metal arc-welding process is presented. The heat source is considered as spatially distributed following a centered Gaussian bell, while the substract material (Al 6063) is assumed homogeneous and isotropic with temperature-dependent thermal properties. Radiation and convection are also calculated through an empirical temperature dependent correlation. Phase-change phenomenon is included as a discontinuity in the material specific heat. Calculations were performed by using a finite volume code (CFX4.2TM). Computed heat penetration and weld metal area are found to be in good agreement with experimental data.
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Numerical simulation of the heat penetration in two-plate arc welding
Article
oai:nur.nu.edu.kz:123456789/8432018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_821
Zhao, Yan
Zhang, Yongguang
Bakenova, Zagipa
Bakenov, Zhumabay
2015-12-02T10:26:44Z
2015-12-02T10:26:44Z
2015-02-02
Zhao, Yan., Zhang, Yongguang., Bakenova, Zagipa., Bakenov, Zhumabay., Carbon/sulfur composite cathodes for flexible lithium/sulfur batteries: status and prospects, 2015 February 02, Frontiers in Energy Research, doi: 10.3389/fenrg.2015.00002
http://nur.nu.edu.kz/handle/123456789/843
High specific energy and low cost flexible lithium/sulfur batteries have attracted significant
attention as a promising power source to enable future flexible and wearable electronic
devices. Here, we review recent progress in the development of free-standing sulfur composite
cathodes, with special emphasis on electrode material selectivity and battery structural
design.The mini-review is organized based on the dimensionality of different scaffold
materials, namely one-dimensional carbon nanotube (CNT), two-dimensional graphene,
and three-dimensional CNT/graphene composite, respectively. Finally, the opportunities
and perspectives of the future research directions are discussed.
lithium/sulfur battery
free-standing cathode
flexible batteries
high-performance batteries
high sulfur loading
Carbon/sulfur composite cathodes for flexible lithium/sulfur batteries: status and prospects
Article
oai:nur.nu.edu.kz:123456789/8442018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Corrales-Barallobre, C.
Martínez-Huen, R.
Alvarez, L.
Polanco, G.
Rojas-Solorzano, L.
2015-12-02T10:37:55Z
2015-12-02T10:37:55Z
2000-06-11
Corrales-Barallobre, C., Martínez-Huen, R., Alvarez, L., Polanco, G., Rojas-Solórzano, L., 2000, Design of a flow deflector for an accurate flow meter calibration facility, http://nur.nu.edu.kz/handle/123456789/844
http://nur.nu.edu.kz/handle/123456789/844
The design and test of a flow deflector gate used for controlling the flow deviation toward the primary tank in a flow-meter calibration facility is presented. The deflector gate is pneumatically controlled and permits the flow conduction to either the suction tank or to the primary tank. The deflector is designed to approximately compensate the flow deficit towards the primary tank during the opening, with the flow excess while in the shutting process. Numerical simulations are performed to study the flow hydrodynamics during the deflector operation. Results are compared to experimental data, and used to improve the gate design. The enhanced design proved to guarantee the uniformity of the flow through the calibration section and the dramatic reduction of the error in volume measurement during calibration.
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Design of a flow deflector for an accurate flow meter calibration facility
Article
oai:nur.nu.edu.kz:123456789/8452018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_821
Zhao, Yan
Yin, Fuxing
Zhang, Yongguang
Zhang, Chengwei
Mentbayeva, Almagul
Umirov, Nurzhan
Xie, Hongxian
Bakenov, Zhumabay
2015-12-02T10:40:53Z
2015-12-02T10:40:53Z
2015-11-19
Zhao Yan., Yin Fuxing., Zhang Yongguang., Zhang Chengwei., Mentbayeva Almagul., Umirov Nurzhan., Xie Hongxian., Bakenov Zhumabay., A free-standing sulfur/Nitrogen-doped carbon nanotube electrode for high- performance lithium/sulfur batteries, 2015 November 19, Nanoscale Research Letters, DOI 10.1186/s11671-015-1152-4
http://nur.nu.edu.kz/handle/123456789/845
A free-standing sulfur/nitrogen-doped carbon nanotube (S/N-CNT) composite prepared via a simple solution
method was first studied as a cathode material for lithium/sulfur batteries. By taking advantage of the self-weaving
behavior of N-CNT, binders and current collectors are rendered unnecessary in the cathode, thereby simplifying its
manufacturing and increasing the sulfur weight ratio in the electrode. Transmission electronic microscopy showed
the formation of a highly developed core-shell tubular structure consisting of S/N-CNT composite with uniform
sulfur coating on the surface of N-CNT. As a core in the composite, the N-CNT with N functionalization provides a
highly conductive and mechanically flexible framework, enhancing the electronic conductivity and consequently
the rate capability of the material.
lithium/sulfur battery
sulfur/nitrogen-doped carbon nanotube composite cathode
free-standing electrode
A free-standing sulfur/nitrogen-doped carbon nanotube electrode for high- performance lithium/sulfur batteries
Article
oai:nur.nu.edu.kz:123456789/8462018-08-15T03:50:25Zcom_123456789_79com_123456789_67col_123456789_826
Corrales-Barallobre, C.
Martínez-Huen, R.
Alvarez, Luis
Polanco, G.
Rojas-Solorzano, L.
2015-12-02T11:05:00Z
2015-12-02T11:05:00Z
2000-06-11
Corrales-Barallobre, C., Martínez-Huen, R., Alvarez, L., Polanco, G., Rojas-Solórzano, L., 2000, Design of a large scale flow-meter test and calibration facility, http://nur.nu.edu.kz/handle/123456789/846
http://nur.nu.edu.kz/handle/123456789/846
The design and set up of a large-scale flowmeter calibration and test facility is presented. The facility was designed to handle flowmeters with diameters between 6” and 14”, flow rates up to 0.3 m3/s and to give results less than 1% accurate. The calibration methodology consisted firstly in calibrating the pattern flowmeters, using volume and time primary measurements, and secondly, comparing the pattern to the flowmeters needing calibration. The design and calculation of the primary calibration device is addressed, including numerical simulations of the outflow manifold and the comparison to experimental data. The calibration facility proved to be accurate and reliable in producing renewed calibration data for various tested flowmeters
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
large-scale flowmeter calibration
Design of a large scale flow-meter test and calibration facility
Article
oai:nur.nu.edu.kz:123456789/8472018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Corrales-Barallobre, C.
Martínez-Huen, R.
Alvarez, Luis
Polanco, G.
Rojas-Solorzano, L.
2015-12-02T11:29:21Z
2015-12-02T11:29:21Z
2000-06-11
Corrales-Barallobre, C., Martínez-Huen, R., Alvarez, L., Polanco, G., Rojas-Solórzano, L., 2000,Design of the distribution manifold for a large-scale flowmeter calibration facility, http://nur.nu.edu.kz/handle/123456789/847
http://nur.nu.edu.kz/handle/123456789/847
The design and test of the distribution manifold for a large-scale flowmeter calibration facility is presented. The design was intended to have an air-free flow operation and a free-surface flow-like towards the downstream half-body discharge. Back of the envelope calculations are presented for the estimation of the preliminary dimensions. Numerical simulations of the flow during manifold steady state operation are utilized to refine the manifold design. No air entrapment is noticed in the flow simulation
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
flowmeter calibration
Design of the distribution manifold for a large-scale flowmeter calibration facility
Article
oai:nur.nu.edu.kz:123456789/8482018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Ortega, P.
McGrath, G.
Rojas-Solorzano, L.
2015-12-03T06:25:41Z
2015-12-03T06:25:41Z
2001-03-12
Ortega, P., McGrath, G., Rojas-Solórzano L., 2001, Two-fluid Mixing Enhancement by Using a Static Turbulence Generator, http://nur.nu.edu.kz/handle/123456789/848
http://nur.nu.edu.kz/handle/123456789/848
The numerical simulation of a static T-type mixer for turbulent mixing of miscible liquids is
reported. The simulation was carried out using CFX, a commercial computational fluid dynamic simulator. The effect of mixing intensification caused by turbulence generators placed downstream of the injection point of the Tee was evaluated in terms of reduction in mixing length for a given mixture quality, uniformity of turbulence intensity and efficiency of energy conversion to useful mixing energy. The mixing quality for an intensified and conventional T-type mixer was compared, and the turbulence generator geometry was optimized. Main stream Reynolds numbers between 50000 and 100000 were considered for additive volume ratios in the range 0.1 - 10%. Selected simulations were validated with experimental data available in the literature for conventional smooth T-type mixers (no ribs). Results were in good agreement with experimental correlations available at high Reynolds numbers. Simulations demonstrated that mixing enhancement was efficient with turbulence generators, extending the Reynolds number range for which compact, low pressure-drop devices may be used for intense mixing. The optimum geometry for turbulence generators was evaluated using criteria based on energetic and spatial efficiency and in all cases the simple Tee was used as the point of reference. Finally, practical design correlations are presented to enable the mixing quality of two miscible streams to be estimated for a simple Tee with and without additional turbulence generators over a range of Reynolds numbers and injection conditions.
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Two-fluid Mixing Enhancement by Using a Static Turbulence Generator
Article
oai:nur.nu.edu.kz:123456789/8492018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
Urthaler, Yetzirah
Viggiani, Pedro
Payares, Carolina
Rojas-Solorzano, L.
2015-12-04T03:55:56Z
2015-12-04T03:55:56Z
2001
Yetzirah Urthaler, Pedro Viggiani, Carolina Payares, Luis Rojas-Solorzano; 2001, Study of the transient temperature profiles induced by changes of the welding parameters during aluminium two plate arc butt-welding, http://nur.nu.edu.kz/handle/123456789/849
http://nur.nu.edu.kz/handle/123456789/849
The numerical study and calculation of transient temperatures developing during the arc-welding process of 6063 T5 aluminum plates is presented. The mathematical model is based on the differential energy conservation equation. The governing equation is solved via numerical simulation using the finite control volume method to obtain the three dimensional and transient temperature profiles induced during the welding process. The moving heat source is considered as represented by a centered Gaussian-Bell distribution, while the base material is assumed to be homogeneous and isotropic with temperature-dependent thermal properties. Radiation and convection are computed and introduced into the model through the boundary conditions as an empirical temperature-dependent correlation. Phase-change phenomenon is included as a discontinuity in the material specific heat. Computed results show the influence of the variation of the welding parameters such as the arc power and welding speed on the computed transient temperatures, penetration and process efficiency
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Study of the transient temperature profiles induced by changes of the welding parameters during aluminium two plate arc butt-welding
Article
oai:nur.nu.edu.kz:123456789/8502018-08-15T03:49:45Zcom_123456789_79com_123456789_67col_123456789_826
Meléndez-Ramírez, Antonio J.
Reyes-Gutiérrez, Miguel A.
Rojas-Solorzano, L.
2015-12-04T04:11:49Z
2015-12-04T04:11:49Z
2004-11-13
Antonio J. Meléndez-Ramírez, Miguel A. Reyes-Gutiérrez, Miguel A. Reyes-Gutiérrez; 2004, Experimental study of a gas-loquid cylindrical cyclone separator performance, http://nur.nu.edu.kz/handle/123456789/850
http://nur.nu.edu.kz/handle/123456789/850
New data of the experimental performance of a Gas-Liquid Cylindrical Cyclone (GLCC) separator are presented. The data were collected using a 2 3/4” (0.07m) ID GLCC model working with an air-glycerin mixture. The inlet liquid flow rate, the inlet gas flow rate, the tangential liquid velocity inside the separator body and the gas carry under were measured for an operation regime without liquid carry over. The influence of the first
three parameters over the gas carry under was established. Results show the separator efficiency is mainly affected by the inlet gas flow rate for the explored conditions with slug flow at the GLCC entrance.
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Gas-Liquid Cylindrical Cyclone separator
Experimental study of a gas-loquid cylindrical cyclone separator performance
Article
oai:nur.nu.edu.kz:123456789/8512018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Arevalo, Angela
Montilla, Gonzalo
Rojas-Solorzano, L.
Reyes, Miguel
Marín, Juan
2015-12-04T04:36:05Z
2015-12-04T04:36:05Z
2006
Arevalo, Angela; Montilla, Gonzalo; Rojas-Solorzano, L.; Reyes, Miguel; Marín, Juan; 2006, CFD modeling of porous media in the study of the flow at penstock intake of A 1:30 model of guri hydro-powerhouse, http://nur.nu.edu.kz/handle/123456789/851
http://nur.nu.edu.kz/handle/123456789/851
The transient free surface flow within a 1:30 model of the intake (penstock) to Power House II of Guri Hydro-Power Plant (Venezuela) is studied. The geometry of the model includes a reservoir of 4.31 meters upstream the dam. Geometric details and appropriate boundary conditions were reproduced mathematical and numerically using CFD (Computational Fluid Dynamics) techniques, running the commercial code CFXTM 4.4. The flow features nearby and within the penstock were captured. Special attention was paid to the evaluation of air entrainment that might eventually form due to the presence of free surface vortices. The computational domain included the anti-debris screen at the entrance of the penstock, considering it as a porous medium with equivalent permeability and porosity. Most of simulated cases corresponded to conditions in the prototype Guri´s free surface level of 240 a.s.l. (above sea level), with flow rate of 450 m3/seg. Air and water were considered incompressible fluids with and homogeneous interfacial transport model. Computed velocity profiles at different sections of the reservoir and pressure head along the penstock are compared with experiments. The numerical model captures the influence of the porous medium, used to simulate the anti-debris grill, onto the free-surface and pressure head within the penstock. In order to improve the predictive capabilities of the numerical model and to diminish the instabilities caused by the hydrostatic pressure condition at the entrance of the computational reservoir, preliminary results including a porous wall at the upstream boundary are presented. The porous wall, in fact, mimics the water-calming rock wall placed at the entrance of the experimental reservoir and proved to be a relevant element in improving the CFD predictions
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
CFD modeling of porous media in the study of the flow at penstock intake of A 1:30 model of guri hydro-powerhouse
Article
oai:nur.nu.edu.kz:123456789/8522018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_825
Adair, Desmond
Ismailov, Kairat
Bakenov, Zhumabay
2015-12-04T04:41:36Z
2015-12-04T04:41:36Z
2014
Adair Desmond., Ismailov Kairat., Bakenov Zhumabay., Thermal Management of Lithium-ion Battery Packs, 2014
http://nur.nu.edu.kz/handle/123456789/852
Temperature affects batteries in five major ways:
•operation of electrochemical system;
•efficiency and charge acceptance;
•power and energy efficiency;
•safety and reliability; and,
•life and life-cycle costs.
Li-ion batteries are extremely sensitive to low and high temperatures.
For battery packs it is important to regulate the pack to remain in the desired temperature range for optimum performance and life, and also to reduce uneven distribution of temperature throughout a packwhich would lead to reduced performance.
Importantly, the attainment of even temperature distributions through the battery pack eliminates potential hazards related to uncontrolled temperature build-up (‘thermal runaway’).
en
thermal management
lithium-ion battery packs
cooling/heating methods
use of COMSOL Multiphysics-1
boundary conditions and settings
Thermal Management of Lithium-ion Battery Packs
Presentation
oai:nur.nu.edu.kz:123456789/8532018-08-15T03:49:45Zcom_123456789_79com_123456789_67col_123456789_826
Reyes, Miguel A.
Pacheco, Jorge E.
Marín, Juan C.
Rojas-Solorzano, L.
Rincón, José
2015-12-04T04:51:31Z
2015-12-04T04:51:31Z
2006-07-17
Miguel A Reyes, Jorge E Pacheco, Juan C Marín, Luis R Rojas, José Rincón, 2006, Numerical simulation and experiments of the multiphase flow in a liquid-liquid cylindrical cyclone separator, http://nur.nu.edu.kz/handle/123456789/853
http://nur.nu.edu.kz/handle/123456789/853
A Liquid-Liquid Cylindrical Cyclone separator (LLCC) is a device used in the petroleum industry to separate the oil-water mixture obtained from the well. The use of this device has not been widespread due to the lack of tools for predicting its separation capability. This paper presents a numerical and experimental study of the fluid dynamic performance of this type of cylindrical cyclone separators. The use of numerical simulations would reduce the time and cost necessary to obtain information for predicting the behavior of the equipment. The objective of this study is to determine if CFD (Computational Fluid Dynamics) techniques are able to reproduce the behavior of a LLCC separator. The CFD software examined was ANSYS-CFX 5.6TM and numerical simulations were carried out using the dispersed model with oil as the dispersed phase. The oil and water mixture entering the separator is divided due to centrifugal and buoyancy forces in an upper (oil rich) exit and a bottom (water rich) exit. The separation capability is determined as the maximum amount of water removed from the mixture with the minimum amount of oil content in the water rich exit. The experiments were conducted in a transparent LLCC separator that allows the visualization of the mixture and the measurement of the oil content. Experiments were conducted for three variables: mixture velocity and water content at the entrance, and the split ratio. The split ratio is defined as the bottom exit flow rate divided by the water flow rate at the entrance. The results showed that CFD tools are able to reproduce the oil content obtained from the experiments for all analyzed conditions. Additionally, the mixture distribution images from numerical and experimental data showed good agreement. This study confirms the capacity of CFD tools for the multiphase flow analysis of LLCC separators.
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
multiphase flow
numerical simulation
oil-water
cyclone
separator
Numerical simulation and experiments of the multiphase flow in a liquid-liquid cylindrical cyclone separator
Article
oai:nur.nu.edu.kz:123456789/8542018-08-15T03:49:45Zcom_123456789_79com_123456789_67col_123456789_821
Bakenov, Zhumabay
Taniguchi, Izumi
2015-12-04T05:10:19Z
2015-12-04T05:10:19Z
2011-12-02
Bakenov Zhumabay., Taniguchi Izumi., 2011, LiMnPO4 olivine as a cathode for lithium batteries, DOI: 10.2174/1874088X01105010222
http://nur.nu.edu.kz/handle/123456789/854
The olivine structured mixed lithium-transition metal phosphates LiMPO4 (M = Fe, Mn, Co) have attracted
tremendous attention of many research teams worldwide as a promising cathode materials for lithium batteries. Among
them, lithium manganese phosphate LiMnPO4 is the most promising considering its high theoretical capacity and
operating voltage, low cost and environmental safety. Various techniques were applied to prepare this perspective cathode
for lithium batteries. The solution based synthetic routes such as spray pyrolysis, precipitation, sol-gel, hydrothermal and
polyol synthesis allow preparing nanostructured powders of LiMnPO4 with enhanced electrochemical properties, which is
mostly attributed to the higher chemical homogeneity and narrow particle size distribution of the material. Up-to-date, the
LiMnPO4/C composites prepared by the spray pyrolysis route have the best electrochemical performance among the
reported in the literature.
en
spray pyrolysis
LiMnPO4
lithium secondary batteries
cathode materials
LiMnPO4 olivine as a cathode for lithium batteries
Article
oai:nur.nu.edu.kz:123456789/8552018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Marval, Juan P.
Rojas-Solorzano, L.
2015-12-04T05:26:19Z
2015-12-04T05:26:19Z
2007-06-30
Juan P. Marval, Luis R. Rojas-Solórzano; 2007; Two-dimensional numerical simulation of saltating particles using granular kinetic theory, http://nur.nu.edu.kz/handle/123456789/855
http://nur.nu.edu.kz/handle/123456789/855
Most granular flows at environmental conditions are unsteady and exhibit a complex physical behavior. Dune formation and migration in the desert are controlled not only by the flow of saltating particles over the sand bed, but also by turbulent atmospheric airflow. In fact, sediments are transported by the atmospheric airflow within a thin layer only a few centimeters above the sandy surface. These jumping particles reach a maximum sediment mass flux level at a certain delay time (known as the “saturation time”) after the initial movement by sliding and rolling begins. Unlike sediment transport in water where the particles are lifted by the turbulent suspension, the saltating particles are kept alive in the layer mainly due to particle-particle and particle-bed collisions. In order to model this Aeolian transport of sand, Jenkins and Pasini [1] proposed a two-fluid model (one-dimensional and steady state) using Granular Kinetic Theory (GKT) to describe the solid-phase stress. The present work extends the original idea of Jenkins and Pasini [1] by using a more robust model of GKT for the kinetic/collisional contributions to the solid-phase stress tensor, together with a friction model activated for sustained contacts between particles. In addition, a standard k-ε turbulence model for the air and a drag model for the interaction between the phases are employed. A rectangular 2D geometry was chosen with a logarithmic profile for the inlet air velocity, along with an initial amount of sand at rest in the lower part of the simulation domain, resembling the particle saltating flow commonly seen in the vertical middle plane within saltation wind tunnels. This model is validated with experimental data from Liu and Dong [2] and the results given by Pasini and Jenkins [1]. A good estimation for the particle erosion and mass flux in the saltation layer is predicted, even though the profiles of mass flux and concentration within the transport layer are very thin and lower
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
saltation layer
Granular Kinetic Theory
CFD
Two-dimensional numerical simulation of saltating particles using granular kinetic theory
Article
oai:nur.nu.edu.kz:123456789/8562018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
Salazar, Félix A.
Rojas-Solorzano, L.
2015-12-04T05:35:04Z
2015-12-04T05:35:04Z
2007-09-24
Félix A. Salazar, Luis R. Rojas-Solórzano; 2007; Selection and validation of a turbulence model for the numerical simulation of the flow at hemodialysis cannulas, http://nur.nu.edu.kz/handle/123456789/856
http://nur.nu.edu.kz/handle/123456789/856
In recent years, CFD has become an increasingly used tool in the design of blood-based devices. Particularly, the estimation of red blood cell damage (hemolysis) becomes an important challenge to CFD scientists since the blood is a complex fluid present in turbulent regime in most pumping devices. Moreover, previous CFD studies on blood hemolysis lack of reliable relationships between hydraulic results and hematological responses. The objective of this work is to foresee a methodology for performing realistic CFD simulations that lead to reliable hydraulic and hematological correspondence. Cannulae geometries were studied to numerically assess a relatively simple flow with documented hematological data. For the turbulence modeling, a direct numerical simulation (DNS) for a coaxial jet array was used as a benchmark for the selection of an appropriate turbulence model, since the Cannulae approximates the coaxial jet features. Velocity and stress time-averaged profiles were compared between DNS results and the turbulence models. These results, pointed to the Shear Stress Transport with Gamma Theta correlation for transition model as the optimum turbulence model in that geometry. Accurate and reliable hydrodynamic CFD results were obtained for the Cannulae as a previous step to further hematological calculations with a minimum degree of uncertainty
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Computational Fluid Dynamics
Turbulence Model
Cannula
Blood
Selection and validation of a turbulence model for the numerical simulation of the flow at hemodialysis cannulas
Article
oai:nur.nu.edu.kz:123456789/8572018-08-15T03:49:45Zcom_123456789_79com_123456789_67col_123456789_826
Hernández, Franz H.
Blanco, Armando J.
Rojas-Solorzano, L.
2015-12-04T05:51:41Z
2015-12-04T05:51:41Z
2008-08-17
Franz H. Hernández, Armando J. Blanco, Luis Rojas-Solórzano; 2008; CFD modeling of slurry flows in horizontal pipes, http://nur.nu.edu.kz/handle/123456789/857
http://nur.nu.edu.kz/handle/123456789/857
Liquid-solid two-phase flows are found in numerous operations in the chemical, petroleum, pharmaceutical and many other industries. In numerous cases, the mixture or slurry that flows is composed by a suspension of solid particles (dispersed phase) transported by a liquid (continuum phase). However, the large number and range of variables encountered in slurry flows, in the case of pipelines, cause the flow behavior of these slurry systems to vary over a wide range of conditions, and consequently, different approaches have been used to describe the behavior of different flow regimes. Therefore, there are numerous studies of particular cases that cover limited ranges of conditions. In consequence, the experimental approach is necessarily limited by geometric and physical scale factors. For these reasons, Computational Fluid Dynamics, CFD, constitutes an ideal technique for predicting the general flow behavior of these systems. CFD models in this area can be divided in two different classes: Eulerian-Eulerian and Lagrangian-Eulerian models. Differences between these models are related to the way the solid phase flow is represented. Lagrangian-Eulerian models calculate the path and motion of each particle, while Eulerian-Eulerian models treat the particle phase as a continuum and average out motion on the scale of individual particles.
This work focuses on the Eulerian-Eulerian approach for modeling the flow of a mixture of sand particles and water in a horizontal pipe. Homogeneous and heterogeneous flow regimes are considered. The k-ε model was used for modeling turbulent effects. Additionally, closure of solid-phase momentum equations requires a description for the solid-phase stress. Constitutive relations for the solid-phase stress considering the inelastic nature of particle collisions based on the Gas Kinetic Theory concepts have been used.
Governing equations are solved numerically using the control volume-based finite element method. An unstructured non-uniform grid was chosen to discretize the entire computational domain. A second-order scheme in space and time was used. Numerical solutions in fully developed turbulent flow were found.
Results show that flow predictions are very sensitive to the restitution coefficient and pseudo-viscosity of the solid phase. The mean pressure gradients from numerical solutions were compared with results obtained using the correlations of Einstein, Thomas and Krieger for homogeneous cases and with experimental data found in the open literature for heterogeneous cases. The solutions were found to be in good agreement with both correlations and experimental data. In addition, these numerical results were closer to experimental data than results obtained using other numerical models.
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
CFD
Computational Fluid Dynamics
CFD modeling of slurry flows in horizontal pipes
Article
oai:nur.nu.edu.kz:123456789/8592018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_821
Hui Pu, Jaan
Bakenov, Zhumabay
Adair, Desmond
2015-12-04T06:12:40Z
2015-12-04T06:12:40Z
2012-01
Hui Pu Jaan., Bakenov Zhumabay., Adair Desmond., 2012, Advanced Numerical Solver for Dam-Break Flow Application
http://nur.nu.edu.kz/handle/123456789/859
In this paper, a HLL (Harten Lax van Leer) approximate Riemann solver with MUSCL scheme
(Monotonic Upwind Schemes for Conservative Laws) is implemented in the presented FV (Finite
Volume) model. The presented model is used to simulate different dam-break flow events to verify its
capability. Four test cases are presented in this paper. In the first test case, a 1-Dimensional (1D) dambreak
flow is simulated over a rectangular channel with different slope limiters of the FV model (namely
Godunov, Superbee, Minmod, van Leer, and van Albada). The second test case consists of a simulation of
shallow water discontinuous dam-break flow over a dry-downstream bed channel. The third test simulates
the shallow water dam-break flow with the existence of bed slope and bed shear stress. Finally, in the last
test, the HLL-MUSCL model used in this paper and some other solver models used in literature are
compared against the referred exact solution in dam-break flow application. The presented HLL-MUSCL
scheme is found to give the best agreement to the exact solution.
en
advanced numerical solver
dam-break flow
Advanced Numerical Solver for Dam-Break Flow Application
Article
oai:nur.nu.edu.kz:123456789/8582018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Salazar, Felix A.
Rojas-Solorzano, L.
Antaki, James F.
2015-12-04T06:05:05Z
2015-12-04T06:05:05Z
2008-08-10
Felix A. Salazar, Luis R. Rojas-Solórzano, James F. Antaki; 2008; Numerical study of turbulence models in the computation of blood flow in cannulas, http://nur.nu.edu.kz/handle/123456789/858
http://nur.nu.edu.kz/handle/123456789/858
In recent years, CFD has become an increasingly used tool in the design of blood-based devices. However, the estimation of red blood cells damage (hemolysis) remains a very important challenge due to the complex rheology of blood and the turbulence present in most pumping devices. The objective of this study was to identify an appropriate turbulence model suitable for predicting hemolysis in Hemodialysis cannula. Several modern turbulence models were evaluated in comparison to Direct Numerical Simulation (DNS), which was used as the gold standard. The fluid dynamics in the cannula was modeled as a coaxial jet in which Reynolds’ number approached 2800. Based on comparison of velocity and stress time-averaged profiles, the Shear Stress Transport (SST) model with Gamma-Theta transition was identified as an optimal compromise between accuracy and computational cost.
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
CFD
Numerical study of turbulence models in the computation of blood flow in cannulas
Article
oai:nur.nu.edu.kz:123456789/8602018-08-15T03:49:45Zcom_123456789_79com_123456789_67col_123456789_821
Zhang, Yongguang
Zhao, Yan
Yermukhambetova, Assiya
Bakenov, Zhumabay
Chen, P.
2015-12-04T06:31:21Z
2015-12-04T06:31:21Z
2013-01
Zhang Yongguang., Zhao Yan., Yermukhambetova Assiya., Bakenov Zhumabay., Chen P., 2013, Ternary sulfur/polyacrylonitrile/Mg0.6Ni0.4O composite cathodes for high performance lithium/sulfur batteries, DOI: 10.1039/c2ta00105e
http://nur.nu.edu.kz/handle/123456789/860
Nanostructured magnesium nickel oxide (Mg0.6Ni0.4O) was synthesized by a self-propagating high
temperature synthesis method followed by heat treatment. The particles of the resulting oxide were
used as additives to prepare the sulfur/polyacrylonitrile/Mg0.6Ni0.4O (S/PAN/Mg0.6Ni0.4O) composite via
wet ballmilling. The SEM observation revealed that the composite morphology was drastically changed
by the addition of Mg0.6Ni0.4O, from smooth bulky particles of S/PAN to rough nanostructured
agglomerates with two times the increase in the specific surface area, favouring the reactivity of the
composite, and a homogeneous component distribution. Cyclic voltammetry, discharge–charge tests and
ac impedance spectroscopy have shown improved conductivity and electrochemical properties of the
composite by the addition of Mg0.6Ni0.4O, leading to high sulfur utilization and interfacial stabilization
in a Li/S cell upon discharge–charge cycling. The cell demonstrated enhanced reversibility, resulting in a
discharge capacity of about 1223 mA h g 1 at the second cycle and retained about 100% of this value
over 100 cycles. Furthermore, the S/PAN/Mg0.6Ni0.4O composite cathode exhibited a good rate
capability with discharge capacities of 887, 710 and 445 mA h g 1 at 0.5, 0.7 and 1 C, respectively.
en
ternary sulfur
polyacrylonitrile
composite cathodes
high performance lithium
sulfur batteries
Ternary sulfur/polyacrylonitrile/Mg0.6Ni0.4O composite cathodes for high performance lithium/sulfur batteries
Article
oai:nur.nu.edu.kz:123456789/8612018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Vittori, Felipe
Rojas-Solorzano, L.
Blanco, Armando J.
Urbina, Rafael
2015-12-04T06:33:46Z
2015-12-04T06:33:46Z
2008-08-10
Felipe Vittori, Luis Rojas-Solórzano, Armando J. Blanco, Rafael Urbina; 2008; Numerical study of smoke propagation in a simulated fire in a wagon within a subway tunnel, http://nur.nu.edu.kz/handle/123456789/861
http://nur.nu.edu.kz/handle/123456789/861
This work deals with the numerical (CFD) analysis of the smoke propagation during fires within closed environments. It is evaluated the capacity of the emergency ventilation system in controlling the smoke propagation and minimizing the deadly impact of an eventual fire in a wagon within the Metro de Caracas subway tunnel on the passengers safety. For the study, it was chosen the tunnel section between Teatros and Nuevo Circo subway stations, which consists of two parallel independent twin tunnels, connected through a transverse passage. The tunnels are provided by a longitudinal ventilation system, integrated by a set of reversible fans located at both ends of the tunnels.
Three stages were considered in the study: (a) Model set up; (b) Mesh sensitivity analysis; (c) Validation of the physical-numerical parameters to be used in the numerical model; and (d) Simulation of fire scenarios in Metro de Caracas subway stations. Stages (b)-(c), aimed to testing and calibrating the CFD tool (ANSYS-CFX10TM), focused on reproducing experimental data from Vauquelin and Mégret [1], who studied the smoke propagation in a fire within a 1:20 scale road tunnel. Stage (d) critical scenarios were established via a preliminary discussion with safety experts from Metro de Caracas, in order to reduce the computer memory and the number of simulations to be performed. The analyses assessed the reliability of escape routes and alternative paths for the evacuation of passengers. Additionally, the smoke front movement was particularly computed, as a function of time, in order to determine the possible presence of the ¨backlayering¨ phenomenon [5]. Results demonstrate the strengths and weaknesses of the current ventilation system in the event of a fire in the subway tunnel, and suggest new strategies to address this potentially lethal event to minimize the risks for passengers
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
CFD
Numerical study of smoke propagation in a simulated fire in a wagon within a subway tunnel
Article
oai:nur.nu.edu.kz:123456789/8622018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
Arzola, Fidel
Rojas-Solorzano, L.
2015-12-04T07:58:37Z
2015-12-04T07:58:37Z
2008-10-27
Fidel Arzola, Luis Rojas-Solórzano; 2008; Numerical simulation of draft tube flow in off-design conditions, http://nur.nu.edu.kz/handle/123456789/862
http://nur.nu.edu.kz/handle/123456789/862
Draft tube flow fields are simulated with 3D unsteady Reynolds averaged Navier-Stokes equations.The purpose of this study is the modeling, simulation and characterization of a complex threedimensional unsteady flow inside a Francis turbine draft tube for two specific off-design conditions: A) Part load (0.88Q), frequently characterized by the occurrence of an unsteady rotating vortex rope linked to strong pressure fluctuations and, B) High load (1.21Q), where softer pressure surges taking place because the cavity volume at this condition has an axisymmetric shape. This work takes place after overhaul works on the actual turbine, which include new runner and wicket gates and modifications on stay vanes and other passageways; where power output, efficiency and stable operating range were increased. The computational domain consists of the draft tube alone. A relative poor mesh (430k nodes) and the k-ε turbulence model are implemented in order to get a quick, but clear explanation to understand how the flow in the existing draft tube responds in front of a new velocity distribution at runner outlet for off-design conditions. Numerical results are qualitative and quantitatively analyzed and compared with experimental data from model and prototype. The unsteady and complex nature of the flow field distribution inside the draft tube for both conditions is visualized
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
draft tube
numerical simulation
vortex rope
pressure fluctuation
Numerical simulation of draft tube flow in off-design conditions
Article
oai:nur.nu.edu.kz:123456789/8632018-08-15T03:49:45Zcom_123456789_79com_123456789_67col_123456789_826
Pineda, Saira F.
Blanco, Armando J.
Rojas-Solorzano, L.
2015-12-04T08:11:30Z
2015-12-04T08:11:30Z
2009-08-02
Saira F. Pineda, Armando J. Blanco, Luis Rojas-Solórzano; 2009, CFD software applications for transcritical free surface flow, http://nur.nu.edu.kz/handle/123456789/863
http://nur.nu.edu.kz/handle/123456789/863
Flows in rivers, floodplains and coastal zones are very complex due to uneven bottom topography and irregular boundaries of the flow domain. In particular, when the flow shows strong gradients in water depth and velocity it is very difficult to predict, with accuracy, flow characteristics such as water profiles in all points of the domain. Traditional approaches solve shallow-water flow equations, known as Saint-Venant equations, when one or two dimension solutions can be adequate for obtaining most of the important flow characteristics. However, complex situations can require solving Navier-Stokes equations. In these cases, a two-phase flow problem must be solved and, as water profiles are not known in advance, only a numerical approach can be used to obtain approximate solutions. In addition, flow can be subcritical, supercritical or in a mixed-flow regime. These flow characteristics and complex geometries can make the use of in-house developed software difficult. The arrival of high performance computers and commercial software packages offers new possibilities in the field of numerical hydraulics. However, commercial software packages should be tested on some specific cases; so that these can be used with confidence. In this paper we solve, several cases of free surface flow that consider subcritical, supercritical, critical, oscillatory depth profiles and hydraulic jumps using a commercial package, CFX™. Most of these cases were proposed as benchmark solutions by MacDonald et al. (1997) for non-prismatic cross section, non-uniform bed slope and transition between subcritical and supercritical flow. Hydraulic jump cases consist of experimental data of hydraulics jumps obtained by Gharangik & Chaudhry (1991) for incident flow with Froude numbers of 2.3 and 4.23. In all simulated cases flow was described using a homogeneous model for each phase of the flow. Turbulence was modeled by using the well-known k-ε model. In addition, sensitivity to turbulence level in the entrance of flow domain was done to assure independence of results with this variable. Experimental facilities were properly represented in order to assure exact correspondence between boundary conditions of the model and the actual facility. Results obtained with CFX™ show excellent agreement with analytical solutions, for subcritical, supercritical, transitional and hydraulic jump cases. Special care with grid selection and entrance boundary condition is crucial to simulate with accuracy these types of flows. In particular, when a proper structured mesh is used, quality results are highly improved. Finally, results show to be insensitive to entrance turbulence conditions
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
CFD software applications for transcritical free surface flow
Article
oai:nur.nu.edu.kz:123456789/8642018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Rojas-Solorzano, L.
Shelley L., Anna
Bradeddine, Bourtal
Amon, Cristina H.
2015-12-04T08:43:49Z
2015-12-04T08:43:49Z
2009-06-22
Luis R. Rojas-Solórzano, Bourtal Bradeddine, Shelley L. Anna, Cristina H. Amon; 2009; Modeling and simulation of a rollerball microfluidic device, http://nur.nu.edu.kz/handle/123456789/864
http://nur.nu.edu.kz/handle/123456789/864
The fluid delivery process through a rollerball device is investigated by means of physical modeling and numerical simulations. The microfluidic device is intended to deliver liquid above a substrate interacting with the surrounding air. While the fluid is delivered, air entrainment occurs through the capillary gap, creating a two-phase liquid-gas mixture whose composition and properties affect significantly the quality of the continuous fluid deposition. For the numerical solution of the 2D two-phase flow governing equations, the finite volumebased finite element method is used with 2nd order time-space schemes for the fully coupled system of equations. The quality of the liquid micro-volume delivery proves to be largely affected by both the speed of the roller and fluid properties. It
is found that only under very low speed and some fluid properties, it is possible to guarantee a gas free liquid deposition. Envisioning the potential use of this convenient and
popular device in the deployment of microfluid layers or substances at very small quantities with controlled quality, it is apparent the need for handling and channeling out the air entrainment without perturbing the liquid quality
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Modeling and simulation of a rollerball microfluidic device
Article
oai:nur.nu.edu.kz:123456789/8652018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
Urbina, Rafael J.
Rojas-Solorzano, L.
Blanco, Armando J.
2015-12-04T08:53:59Z
2015-12-04T08:53:59Z
2009-04
Rafael J. Urbina, Luis Rojas-Solórzano, Armando J. Blanco; 2009; CFD modeling of a road tunnel with multiple sources of Co. case of study: boqueron-I tunnel, http://nur.nu.edu.kz/handle/123456789/865
http://nur.nu.edu.kz/handle/123456789/865
This work aims to the modeling of CO transport in one section considered critical of the
Boqueron I tunnel, located on the outskirts of Caracas, the capital city of Venezuela, with a
scenario where vehicles are stopped by an interruption of traffic. This scenario considers a relationship between the number of large-sized vehicles (buses or trucks) and small-sized vehicles (passenger cars) reported by transit statistics and also, it considers the semi-transverse ventilation system in the tunnel. It is explored the influence of the ventilation on the flow patterns and its relationship to the regions with the highest CO concentration. The finite-volume based finite element method is used for the discretization of the computational domain and the integration of the governing equations. The transient 3D-incompressible Navier-Stokes, energy, mass and species conservation equations, along with the k-e turbulence equations, were discretized, using higher-order numerical schemes in space. The numerical simulation is performed using a fully implicit coupled treatment of the set of resulting discrete transport equations
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
CFD modeling of a road tunnel with multiple sources of Co. case of study: boqueron-I tunnel
Article
oai:nur.nu.edu.kz:123456789/8662018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
Akiki, Georgio
Hinrichs, Federico
Zuylen, Roderick A.
Rojas-Solorzano, L.
2015-12-04T09:10:39Z
2015-12-04T09:10:39Z
2010-11-05
Georgio Akiki, Federico Hinrichs, Roderick A. van Zuylen, Luis Rojas-Solórzano; 2010; Pre-feasibility study for PV electrfication of off-grid rural communities,http://nur.nu.edu.kz/handle/123456789/866
http://nur.nu.edu.kz/handle/123456789/866
A pre-feasibility study has been undertaken for the electrification of the rural off-grid village of Hurhudedanda, Nepal. PV solar was deemed most suitable after an assessment of local wind, micro-hydro, solar and biogas potential. To determine the most cost-effective PV configuration, different scenarios were simulated using RETscreenTM. Decentralized Solar Home Systems (SHS) resulted in lower life cycle costs than centralized PV generation (1.25 $/kWh and 1.46 $/kWh respectively) and might be the best alternative for a first stage of electrification. A final study has been undertaken to assess the proposed system’s ability to deal with a forecasted load increase
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Photovoltaic system
Rural electrification
Life cycle cost
RETscreenTM
Pre-feasibility study for PV electrfication of off-grid rural communities
Article
oai:nur.nu.edu.kz:123456789/8672018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Roldan, Constantino
Pieretti, Pedro
Rojas-Solorzano, L.
2015-12-04T09:21:16Z
2015-12-04T09:21:16Z
2010
Constantino Roldan, Pedro Pieretti, Luis Rojas-Solórzano; 2010; Conceptual and basic design of a stirling engine prototype for electrical power generation using solar energy, http://nur.nu.edu.kz/handle/123456789/867
http://nur.nu.edu.kz/handle/123456789/867
The research consisted in a conceptual and basic design of a prototype Stirling engine with the purpose of taking advantage of the solar radiation to produce electric energy. The
work began with a bibliography review covering aspects as history, basic functioning, design configurations, applications and analysis methods, just to continue with the conceptual design, where the prototype specifications were determined. Finally, a basic dimensioning of the important components as heat exchangers (heater, cooler, and regenerator), piston, displacer and solar collector was elaborated. The principal conclusions were that the different analysis methods had dissimilitude among their results; in this sense, a construction of the prototype is necessary for the understanding of the complex phenomena occurring inside the engine
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Conceptual and basic design of a stirling engine prototype for electrical power generation using solar energy
Article
oai:nur.nu.edu.kz:123456789/8682018-08-15T03:50:25Zcom_123456789_79com_123456789_67col_123456789_826
Filonovich, M.
Azevedo, R.
Rojas-Solorzano, L.
Leal, J. B.
2015-12-04T09:31:08Z
2015-12-04T09:31:08Z
2010
M. Filonovich, R. Azevedo, L. R. Rojas-Solorzano, J. B. Leal; 2010; Simulation of the Velocity field in compound channel flow using different closure models, http://nur.nu.edu.kz/handle/123456789/868
http://nur.nu.edu.kz/handle/123456789/868
In this study a comparison of three turbulence closure models (two isotropic and one anisotropic) with experimental data is performed. The interaction between the main channel (MC) flow and the floodplain (FP) generates a complex flow structure. A shallow mixing layer develops between the MC flow and the slower FP flow generating a high horizontal shear layer, streamwise and vertical vortices, momentum transfer and other phenomena, related to velocity retardation and acceleration. This phenomenon dissipates part of the kinetic energy and contributes to the reduction of the velocity differences between the MC and the FP. The large scale vortices that are generated in the shear layer are anisotropic, provoking the formation of secondary flow cells that influence the primary velocity distribution. These threedimensional turbulent structures can be reasonable well reproduced by a simple anisotropic model (Algebraic Stress Model). The isotropic models are capable of simulating the boundary layer, especially the model base in k-ω equations,
but cannot simulate the shear layer that develops at the interface
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Simulation of the Velocity field in compound channel flow using different closure models
Article
oai:nur.nu.edu.kz:123456789/8692018-08-15T03:49:45Zcom_123456789_79com_123456789_67col_123456789_826
Koh, Pei Ling
Pomarico, Victor
Tadepalli, Venkata Phani
Rojas-Solorzano, L.
2015-12-04T10:03:27Z
2015-12-04T10:03:27Z
2010-11-05
Pei Ling Koh, Victor Pomarico, Venkata Phani Tadepalli, Luis Rojas-Solórzano; 2010; Pre-feasibility study of a biogas plant for peyrelevade community, http://nur.nu.edu.kz/handle/123456789/869
http://nur.nu.edu.kz/handle/123456789/869
This work presents a technical and financial pre-feasibility assessment for heat generation from biogas for a retirement home in the community of Peyrelevade, France. The heat demand of the retirement home currently relies on fuel oil boiler and electric heaters. The biogas is to be produced mainly from grass silage. As result of the feedstock abundance in the community, electricity can be also generated in an 80kWe CHP unit operating in full power capacity. The electricity produced can be then sold to the national electricity utility in France. The financial analysis was carried out using RETScreenTM. An efficiency of 62.9% is achievable in this CHP (Combined heat and power) biogas plant, with a total life cycle saving/income of 0.05€ for each MJ of heat supplied to the retirement home. A company set-up has also been proposed for the development of a community based company
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Grass Silage
Biogas
Boiler
CHP
RETScreen
Pre-feasibility study of a biogas plant for peyrelevade community
Article
oai:nur.nu.edu.kz:123456789/8702018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Filonovich, M. S.
Azevedo, R.
Rojas-Solorzano, L.
Leal, J. B.
2015-12-04T10:16:00Z
2015-12-04T10:16:00Z
2010
M. S. Filonovich, R. Azevedo, L. R. Rojas-Solorzano, J. B. Leal; 2010; Verification and validation of computational fluid dynamics simulations of compound channel, http://nur.nu.edu.kz/handle/123456789/870
http://nur.nu.edu.kz/handle/123456789/870
In this study the verification and validation of a 2nd order turbulence closure model is performed for an experimental compound channel flow, where the velocity field was measured by a Laser Doppler Velocimeter. Detailed Explicit Algebraic Reynolds Stress Model (EARSM) simulation is reported. The Grid Convergence Index (GCI) approach proposed by Roache (1998) was adopted to evaluate the uncertainty associated to grid resolution. The velocity components, the turbulent kinetic energy (TKE) and the dissipation rate were used as variables of interest. The GCI results present low values for the streamwise velocity, TKE and dissipation rate, but higher values in what concerns vertical and spanwise velocities. This indicates that the mean primary flow has converged but the secondary flow field still depends on grid resolution. Based on GCI values distribution, the mesh was locally refined. Comparison of numerical and experimental results shows good agreement
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
CFD
GCI
EARSM
compound channel
verification
validation
Verification and validation of computational fluid dynamics simulations of compound channel
Article
oai:nur.nu.edu.kz:123456789/8712018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
F., Vittori
Rojas-Solorzano, L.
Pavageau, M.
2015-12-04T10:38:16Z
2015-12-04T10:38:16Z
2011
Vittori F., Rojas-Solórzano L., Pavageau M.; 2011; Comparative study of rans turbulence models for impinging jet simulations, http://nur.nu.edu.kz/handle/123456789/871
http://nur.nu.edu.kz/handle/123456789/871
Impinging plane jets are flow configurations with applications in many fields. The ability of several turbulence models to simulate this kind of flow was assessed. The numerical results were compared with the data of Cooper et al. (1993) for Re=7.0 104 and a jet nozzle aspect ratio H/D=6, and Re=2.3 104 and H/D=2. The SST, RSM-ε and RSM-BSL turbulence models were chosen because of their capability to predict flows with high streamline curvature and their expected good accuracy on near wall flow. The results show that the SST and RSM- ε perform better than the RSM-BSL in the prediction of the mean velocity profiles in the wall-jet and impact zone. The profiles of turbulent energy were particularly difficult to reproduce. All the turbulence models considered here exhibit a similar behavior with respect to the profiles of turbulent energy. The paper shows again the complexity of turbulent impinging jets and the relevant open challenges in CFD
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Comparative study of rans turbulence models for impinging jet simulations
Article
oai:nur.nu.edu.kz:123456789/8722018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Riera-Ortiz, Jaime
Zeppieri, Suzana
Rojas-Solorzano, L.
Derjani, Sylvana
2015-12-04T11:27:41Z
2015-12-04T11:27:41Z
2011
Jaime Riera-Ortiz, Suzana Zeppieri, Luis Rojas-Solorzano, Sylvana Derjani; 2011; CFD Simulation of Air-water in a Spouted Bed
http://nur.nu.edu.kz/handle/123456789/872
Computational fluid dynamics (CFD) is employed to simulate the air-water system in a spouted column with a draft tube. Numerical results of Reynolds-averaged Navier-Stokes (RANS) equations using the k-s and k-w two-equation turbulence models are compared with Pironti at al. (1995) experimental data. CFD predictions of the k-s and k-w turbulence models are in good agreement with the reported experimental data. The interfacial momentum transfer in modeling air-water system in the spouted bed indicated the importance of using turbulent dispersion force besides the most often used drag and lift forces to better predict flow behavior and air hold-up. Ishii-Zuber liquid-gas drag model with the lift and turbulent dispersion forces yields very good results; it correctly determines a hold up within 1% when used along with the k-s turbulence model, while it under-predicts the hold-up by 4.08% when used with the k-co model.
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
CFD Simulation of Air-water in a Spouted Bed
Article
oai:nur.nu.edu.kz:123456789/8732018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_825
Hara, Toru
Konarov, Aishuak
Mentbayeva, Almagul
Kurmanbayeva, Indira
Bakenov, Zhumabay
2015-12-04T11:33:10Z
2015-12-04T11:33:10Z
2013
Hara Toru., Konarov Aishuak., Mentbayeva Almagul., Kurmanbayeva Indira., Bakenov Zhumabay., Lithium sulfur battery: current status and future prospects
http://nur.nu.edu.kz/handle/123456789/873
This publication has been made within the Sub-project #157-2013 which is funded under the Technology Commercialization Project, supported by the World Bank and the Government of the Republic of Kazakhstan.
en
lithium sulfur battery
future prospects
Lithium sulfur battery: current status and future prospects
Presentation
oai:nur.nu.edu.kz:123456789/8742018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_825
Adair, D.
Hara, Toru
Massalin, Y.
Ismailov, K.
Bakenov, Zhumabay
2015-12-04T11:49:28Z
2015-12-04T11:49:28Z
2015-11-11
Adair D., Hara T., Massalin Y., Ismailov K., Bakenov Z., 2015, Analytical modelling of planar potential and current distributions in electrodes of lithium-Ion batteries
http://nur.nu.edu.kz/handle/123456789/874
Mathematical modelling can play an important role in the design of a lithium-ion cell
in that many design iterations can be performed at relatively little cost.
• Electrochemical models are useful for cell design and optimization but can be
typically high-order and complex and hence computationally expensive, and, are
therefore not suitable for real-time applications.
• Much reduced order electrochemical models for lithium-ion cells have been
developed, with these type of models more suitable for use with real-time on-board
electronic control units.
• However, a difficulty with these methods is that the current-voltage behavior for
different operating conditions cannot be predicted.
en
analytical modelling
electrodes of lithium-Ion batteries
Analytical modelling of planar potential and current distributions in electrodes of lithium-Ion batteries
Presentation
oai:nur.nu.edu.kz:123456789/8752018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_825
Hara, Toru
Antonov, Anton
Umirov, Nurzhan
Bakenov, Zhumabay
2015-12-04T11:59:05Z
2015-12-04T11:59:05Z
2015-11-11
Hara Toru., Antonov Anton., Umirov Nurzhan., Bakenov Zhumabay., 2015, Three-dimensional Zn/LiFePO4 aqueous hybrid-ion battery for renewable energy integration into electrical grids
http://nur.nu.edu.kz/handle/123456789/875
Renewable energy integration into electrical grids is crucial for energy security, leading to the highly secured communication network, traffic control, industrial activities, etc.
Renewable energies are intermittent and cannot be easily directly integrated to electric grids without using batteries.
These batteries must be safe and inexpensive from the viewpoint of life-cycle cost.
Aqueous batteries are non-flammable that can be a great merit compared with traditional lithium-ion batteries that use flammable organic electrolyte solutions.
en
three-dimensional Zn/LiFePO4
aqueous hybrid-ion battery
renewable energy integration
electrical grids
Three-dimensional Zn/LiFePO4 aqueous hybrid-ion battery for renewable energy integration into electrical grids.
Presentation
oai:nur.nu.edu.kz:123456789/8762018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
Durán-García, Martín
Ramírez, Yrina
Bravo, Ricardo
Rojas-Solorzano, L.
2015-12-07T04:18:50Z
2015-12-07T04:18:50Z
2012-02
Martín Durán-García, Yrina Ramírez, Ricardo Bravo, Luis Rojas-Solórzano; 2012; Biogas home-production assessment using a selective sample of organic vegetable waste. A preliminary study; http://nur.nu.edu.kz/handle/123456789/876
http://nur.nu.edu.kz/handle/123456789/876
Biogas generation plants using organic waste are a daily reality that can be observed in different areas of waste disposal that exist in many cities of the world. In fact, the generation of biogas through anaerobic bio-digestion of urban wastes has a high impact in terms of energy use and reduced environmental liabilities. The present study focuses on the assessment of biogas production for domestic consumption; several biodigesters
were tested in order to evaluate the biogas production under
standard pressure and temperature. The test estimates volume
of biogas being produced, substrate pH and substrate concentration,
using different types of catalysts. A test bed was designed
for testing three digesters (A, B and C) within recycled
bottles of polyethylene terephthalate (PET), whose maximum
volume is ~0.6 liters. A 60g organic substrate compound was
placed in each bottle. The organic compound consisted of peeling
residues of potatoes, cabbage and carrots. Experimental
characterization of the mixture allowed to observe the production
of biogas for domestic use, system temperature, pH levels
achieved, mass and substrate concentration, as well as concentration
and volume of the catalyst. Further studies, with a
larger sample and monitoring the container pressure are recommended
in order to establish a more precise relation among
the whole set of experimental parameters.
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Anaerobic Digestion
Biodigesters
Biogas
Biomethane Potential Measurement
Substrate
Biogas home-production assessment using a selective sample of organic vegetable waste. A preliminary study
Article
oai:nur.nu.edu.kz:123456789/8772018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_821
Riera Ortiz, Jaime. A.
Zeppieri, Susana
Rojas-Solorzano, L.
Derjani-Bayeh, Sylvana
2015-12-07T04:36:02Z
2015-12-07T04:36:02Z
2011-04-14
Jaime. A. Riera Ortiz, Susana Zeppieri, Luis Rojas-Solorzano, Sylvana Derjani-Bayeh; 2011; Evaluation of Interphase Drag Models for the Determination of Gas Hold-Up of an Air-Water System in a Spouted Bed using CFD, http://nur.nu.edu.kz/handle/123456789/877
http://nur.nu.edu.kz/handle/123456789/877
Abstract: The hydrodynamics of a dispersed air-water system within a spouted column with a concentric draft tube and a conical base is simulated using CFD based on a two–fluid Euler–Euler (E-E) modeling framework and k-ε two-equation turbulence closures. The interaction between the dispersed gas phase and the continuous liquid phase is characterized by bubble–liquid interphase forces (drag, turbulent dispersion and lift forces). The Ishii-Zuber drag model [1] and Grace adjusted drag model [2], the latter represented by: GraceDpg Grace dense D C C , , are compared for their capability to match experimental gas hold- up. Numerical results of Reynolds-averaged Navier-Stokes equations with k-ε two-equation turbulence closures models when compared with
Pironti experimental data [3] indicated that both drag models, predicted the air hold-up within experimental error. Furthermore, Ishii-Zuber liquid-gas drag model consistently provided better agreement of experimental results; it correctly determines the hold-up within 0.14%. Numerical agreement with adjusted Grace liquid-gas drag model, is exponent dependent 4 p 0.5, turning down that the best computed hold-up is within 0.44%. for p 0.5.
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Interfacial drag models
Holdup
Spouted bed column
CFD
k-ε
Evaluation of Interphase Drag Models for the Determination of Gas Hold-Up of an Air-Water System in a Spouted Bed using CFD
Article
oai:nur.nu.edu.kz:123456789/8782018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Inglezakis, V.
Rojas-Solorzano, L.
Kim, J.
Moustakas, K.
Aitbekova, A.
Ismailova, A.
Shorakyzy, G.
Kystauova, A.
Abirov, A.A.
Serikbayev, N.S.
2015-12-07T05:02:01Z
2015-12-07T05:02:01Z
2014
Inglezakis V., Rojas-Solorzano L., Kim J., Moustakas K., Aitbekova A., Ismailova A., Shorakyzy G., Kystauova A., Abirov A.A., Serikbayev N.S.; 2014; Analysis of Current Situation in Municipal Waste Management and Implementation of Decision Support Software in Astana, Kazakhstan; http://nur.nu.edu.kz/handle/123456789/878
http://nur.nu.edu.kz/handle/123456789/878
The city of Astana, capital of Kazakhstan with population of 804,474 generates approximately 1.39 kg/inh./day of municipal solid waste while collection rate is higher than 72% (MSW). An MBT plant of planned capacity of 600-800 tn/day and a new landfill cell of about 2 million tones are in place. Preliminary studies showed that the MSW composition is as follows: food and garden waste 29.5%, plastics 18.5%, paper 13%, glass 14.5%, textiles 9.5%, metals 0.9% and others 14.1%. About 23-34 tons of recyclables (paper, metal, glass, PET bottles, HDPE film, HDPE plastic, etc.) is separated in the existing MBT daily. In 2014 it is planned to implement separate waste collection in places of waste accumulation and a waste separation at source system. The purpose of the study is to assess the current situation of municipal solid waste in Astana and implement a Decision Support Software tool developed by the research team in order to analyse data, compare alternative waste management scenarios and propose a holistic approach in solid waste management planning. The latest available data on waste generation, composition and existing infrastructure were used in order to identify the baseline situation. This is the first research of this type conducted in Kazakhstan
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
municipal solid waste
waste management
Analysis of Current Situation in Municipal Waste Management and Implementation of Decision Support Software in Astana, Kazakhstan
Article
oai:nur.nu.edu.kz:123456789/8792018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_821
Abilgaziyev, Anuar
Nogerbek, Nurbol
Rojas-Solorzano, L.
2015-12-07T05:10:07Z
2015-12-07T05:10:07Z
2015-10-27
Anuar Abilgaziyev, Nurbol Nogerbek, Luis Rojas-Solórzano; 2015; Design Optimization of an Oil-Air Catch Can Separation System; http://nur.nu.edu.kz/handle/123456789/879
http://nur.nu.edu.kz/handle/123456789/879
The Positive Crankcase Ventilation (PCV) system in a car engine is designed to lower the pressure in the crankcase, which otherwise could lead to oil leaks and seal damage. The rotation of crankshaft in the crankcase causes the churn up of oil which conducts to occurrence of oil droplets which in turn may end in the PCV exhaust air intended to be re-injected in the engine admission. The oil catch can (OCC) is a device designed to trap these oil droplets, allowing the air to escape from the crankcase with the lowest content of oil as possible and thus, reducing the generation and emission of extra pollutants during the combustion of the air-fuel mixture. The main purpose of this paper is to optimize the design of a typical OCC used in many commercial cars by varying the length of its inner tube and the relative position of the outlet from radial to tangential fitting to the can body. For this purpose, CFD parametric analysis is performed to compute a one-way coupled Lagrangian-Eulerian two-phase flow simulation of the engine oil droplets driven by the air flow stream running through the device. The study was performed using the finite volume method with second-order spatial discretization scheme on governing equations in the Solid Works-EFD CFD platform. The turbulence was modelled using the k-ɛ model with wall functions. Numerical results have proved that maximum efficiency is obtained for the longest inner tube and the tangential position of the outlet; however, it is recommended further investigation to assess the potential erosion on the bottom of the can under such a design configuration
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
CFD
Oil Catch Can
Positive Crankcase Ventilation
Motor Oil Droplets
Mesh Refinement
Two-Phase Flow
Lagrangian-Eulerian
Design Optimization of an Oil-Air Catch Can Separation System
Article
oai:nur.nu.edu.kz:123456789/8802018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Trejo, Victor
Diaz, Gabriela
Rojas-Solorzano, L.
2015-12-07T05:51:10Z
2015-12-07T05:51:10Z
2015-04
Trejo Victor, Diaz Gabriela, Rojas-Solorzano L.; 2015; Technical and economic prefeasibility study of mini-hydro power plants in Venezuela. Case study: El Valle River; http://nur.nu.edu.kz/handle/123456789/880
http://nur.nu.edu.kz/handle/123456789/880
The technical and economic feasibility of the installation of a mini-hydroelectric power plant on El Valle River in Venezuela is assessed. Special attention is paid to modeling Venezuela’s energetic and economic scenarios. Sensitivity, risk and emission analyses are also carried out. The results of the study show very attractive economic indicators, such as a 280.3% internal rate of return and a 0.4 years pay-back period. The positive results of the study are indication that clean energies could find very fertile scenarios in countries such as Venezuela, where the advantages of their application may not be evident
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Renewable energies
prefeasibility analysis
hydric resource
Technical and economic prefeasibility study of mini-hydro power plants in Venezuela. Case study: El Valle River
Article
oai:nur.nu.edu.kz:123456789/8812018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
Adamu, Victor
Ampofo, Nana
Pramono Jati, Ario Panggi
Tulabing, Ryan
Rojas-Solorzano, L.
2015-12-07T06:01:52Z
2015-12-07T06:01:52Z
2015-04
Adamu Victor, Ampofo Nana, Pramono Jati Ario Panggi, Tulabing Ryan, Rojas Solorzano Luis; 2015; Technical-Economic Prefeasibility Assessment of an off-grid Mini-Hydro Power Plant for an Agribusiness Resort in Kaduna Nigeria; http://nur.nu.edu.kz/handle/123456789/881
http://nur.nu.edu.kz/handle/123456789/881
Clean energy technologies are beginning to receive attention in Nigeria to offset the increasing greenhouse gas emissions. These emissions are associated to the wide use of small-scale fossil-fuel-powered generators by about 55% of its 180-million people yet to be connected to the grid. While a large hydropower potential exists in Nigeria, even above the total electricity demand of the country, by 2013 this technology only accounted for about 32% of the total installed generation capacity connected to the grid. Previous studies have limited results in terms of technical, economic and environmental evidences that can drive choices towards small hydro and other clean energy projects for users and technology providers in Nigeria. This study uses the RETScreen Software to analyse the technical, economic and environmental aspects of a proposed mini-hydro power plant on the Tuwan River, to supply part of the energy needs of Tuwan Agribusiness Resort (TAR) located in Madakiya district, a rural community in Kaduna State, Nigeria. The volumetric flow and gross head of the chosen river were measured and the power generation system design yielded a 21kW power output, capable to partially offset the present use of diesel generators and achieve a 307.4 tCO2 equivalent GHG emission reduction. The financial analysis showed an attractive Internal Rate of Return (IRR) of 68.1% and NPV of 568,178 USD (11% discount rate), owing to the high potential of the project to attract grants and tax rebates, which were put into consideration in the financial analysis. This study is important for Tuwan Agribusiness Resort, an agribusiness service provision outfit with a potential to create over 1000 jobs when fully operational
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Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Mini-hydro
pre-feasibility
clean energy
green-house-gas
Nigeria
Technical-Economic Prefeasibility Assessment of an off-grid Mini-Hydro Power Plant for an Agribusiness Resort in Kaduna Nigeria
Article
oai:nur.nu.edu.kz:123456789/8822018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
Assamidanov, Anuar
Nogerbek, Nurbol
Rojas-Solorzano, L.
2015-12-07T06:13:54Z
2015-12-07T06:13:54Z
2015-04
Assamidanov Anuar, Nogerbek Nurbol, Rojas-Solorzano L.; 2015; Technical and economic prefeasibility analysis of residential solar PV system in South Kazakhstan; http://nur.nu.edu.kz/handle/123456789/882
http://nur.nu.edu.kz/handle/123456789/882
In the family of the renewable technologies, photovoltaic (PV) systems today attract considerable attention (Dornfeldt, 2013). However, on-grid PV market is not a profitable sector by itself. It is dependent on the governmental support, which still must stimulate investment with subsidies. Thus, this paper presents the technical and economic prefeasibility analysis of implementing a residential photovoltaic system in South Kazakhstan, using the clean energy project analysis tool RETScreen® V.4. The different systems available for PV cells are considered, however, with the climatic conditions in South Kazakhstan, the study focuses on polycrystalline solar cells (Poly-Si) due to its optimal specifications for the region. Furthermore, local company Astana Solar has implemented a production line of Poly-Si photovoltaic modules using Kazakhstani silicon (Astana Solar, 2012), which could make the project even more attractive to the country.
In the analysis presented, solar resource in South Kazakhstan was estimated using solar radiation data from NASA Surface Meteorology and Solar Energy. For a 6.6 kWp system, installed in the roof of a home, it is found that 8 834 MWh of electric energy is exported to the grid in average per year. The suitability of city-level Feed in Tariffs (FITs) to promote solar photovoltaic panels in Kazakhstan is included in the analysis, despite it is very recent and had not been thoroughly examined yet (Ministry of Energy of Kazakhstan, 2014). Several different economic and financial indicators were calculated, such as the Internal Rate of Return (IRR), Net Present Value (NPV), Benefit-Cost (B-C) ratio, Cost of Energy Production (CEP) and Simple Payback (SP). All indicators for all sites explored in South Kazakhstan showed favorable conditions for deployment of the proposed residential solar PV system. The highest IRR of 17.9%, NPV of $14523 and B-C ratio of 9.65 was observed in Shymkent and the lowest IRR of 16%, NPV of $11366 and B-C ratio of 7.84 was observed in Taraz. Meanwhile, it can be observed that Shymkent got the shortest SP period of 9.9 years and Taraz got the longest payback period of 10.8 years.
The technical and economic analysis shows also that the implementation of an additional 50% subsidy on total initial cost recently approved, affected very positively the PV-based generation system in southern regions. Therefore, it is found that all southern Kazakhstan is a fertile territory to implement on-grid residential projects
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Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Solar photovoltaics
renewable energy
prefeasibility analysis
RETScreen
Technical and economic prefeasibility analysis of residential solar PV system in South Kazakhstan
Article
oai:nur.nu.edu.kz:123456789/8832018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
Benavides, Sara
Bitosova, Maria
Gregorio, Javier
Welschbilling, Aubin
Rojas-Solorzano, L.
2015-12-07T06:30:53Z
2015-12-07T06:30:53Z
2015-04
Benavides Sara, Bitosova Maria, Gregorio Javier, Welschbilling Aubin, Rojas-Solorzano L.; 2015; Technical-Economic Assessment of Energy Efficiency Measures in a Mid-Size Industry; http://nur.nu.edu.kz/handle/123456789/883
http://nur.nu.edu.kz/handle/123456789/883
The industry sector is facing many challenges such as global competition, energy pricing, environmental impact amongst others. Consequently, the necessity of energy efficiency measures has become evident; framing the objective of this project as to assess the technical and economic pre-feasibility of implementing energy efficiency measures in a dairy products manufacturing company located at the south of the Reunion Island with the help of RETSCreen ® a Clean Energy Project Analysis Software. The scope of the project is focused in one of the nine buildings where the company accomplishes different production processes, specifically in the ultra-high temperature pasteurization facility building (UHT)
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Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Energy Efficiency
prefeasibility analysis
mid-size industry
RETScreen
Technical-Economic Assessment of Energy Efficiency Measures in a Mid-Size Industry
Article
oai:nur.nu.edu.kz:123456789/8842018-08-15T03:49:46Zcom_123456789_79com_123456789_67col_123456789_826
Idowu, Olugbeminiyi
Ige, Toluwalope
Legenski, Nicole
Mustafa, Amin A.
Rojas-Solorzano, L.
2015-12-07T08:17:17Z
2015-12-07T08:17:17Z
2015-04
Idowu Olugbeminiyi, Ige Toluwalope, Legenski Nicole, Mustafa Amin A., Rojas-Solorzano L.; 2015; Technical and economical prefeasibility study of a solar water heating (SWH) system in an apartment building in Cape Town; http://nur.nu.edu.kz/handle/123456789/884
http://nur.nu.edu.kz/handle/123456789/884
Solar power has significant potential to reduce reliance on conventional energy sources in South Africa. A prefeasibility study for a communal solar water heating system (SWHS) is performed for an apartment building in the Cape Town area. Energetic-economic modelling of the system is performed via the calculation of the solar fraction, and fundamental indicators of the financial analysis such as internal rate of return (IRR), net present value (NPV), and benefit-cost ratio. Results indicate that a SWHS with a solar fraction of 32% and a benefit-cost ratio of 3.05 is realizable. Additionally, sensitivity analysis of financial results with respect to incentive rebate amount and electricity escalation rate is performed
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Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Solar Water Heaters
Cape Town
RETScreen
Prefeasibility
Glazed solar collectors
Unglazed solar colletors
Electricity saving
Technical and economical prefeasibility study of a solar water heating (SWH) system in an apartment building in Cape Town
Article
oai:nur.nu.edu.kz:123456789/8852018-08-15T03:49:45Zcom_123456789_79com_123456789_67col_123456789_826
Marcano, A.
Rojas-Solorzano, L.
Reyes, M.
2015-12-07T08:27:04Z
2015-12-07T08:27:04Z
2004-04
A. Marcano, L. Rojas-Solórzano, M. Reyes; 2004; 3D CFD Modeling Investigation of Potential Vortex Formation at the Intakes of Caruachi Powerhouse; http://nur.nu.edu.kz/handle/123456789/885
http://nur.nu.edu.kz/handle/123456789/885
In this paper, the 3-D CFD simulation of the free-surface flow approaching the
intakes of Caruachi Powerhouse is presented. The aim of the investigation is to determine
whether or not vortex structures are likely to appear from the water surface through the intakes, as the result of the presence of cofferdams placed few meters upstream of the intakes. The presence of cofferdams was a note of concern with regard to the effects they might have on the turbine intakes once the hydroelectric central starts operating. In all the considered conditions, results did not show neither strong surface vortices in the proximities of the Power House intakes, nor air entrainment-entrapment towards the intakes, which reflects the safe operation of the turbines in the presence of the cofferdams. The latter added in decision taking on leaving the cofferdams submerged instead of removing them, which resulted in cost savings for the project
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Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
CFD
3D CFD Modeling Investigation of Potential Vortex Formation at the Intakes of Caruachi Powerhouse
Article
oai:nur.nu.edu.kz:123456789/8862018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
Azevedo, Ricardo
Rojas-Solorzano, L.
Leal, João
2015-12-07T08:55:49Z
2015-12-07T08:55:49Z
2012-06
Ricardo Azevedo, Luis Rojas-Solórzano, João Leal; 2012; Experimental Characterization of straight compound-channel turbulent field; http://nur.nu.edu.kz/handle/123456789/886
http://nur.nu.edu.kz/handle/123456789/886
Straight compound-channel flows have been studied by many authors, mainly concerned with mean flow variables. Detailed information on the complex turbulent field of these flows is still scarce. In the present paper, high data rate measurements were obtained for the streamwise and vertical velocity components, using a 2D Laser Doppler Velocimeter in a experimental compound flume. The filtered velocities time series allowed the computation of relevant turbulence statistics: autocorrelation functions, dissipation spectra, turbulence scales and dissipation rate. The results are analyzed by comparison with universal laws drawn for isotropic turbulent 2D fully developed open-channel flow. The presence of strong secondary currents does not affect the universal law in the floodplain, as long as the constants are changed. In the main channel the 3D behavior of the flow is more pronounced and the universal laws fail to reproduce accurately the experimental results
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
2D Laser Doppler Velocimeter
Experimental Characterization of straight compound-channel turbulent field
Article
oai:nur.nu.edu.kz:123456789/8872018-08-15T03:49:47Zcom_123456789_79com_123456789_67col_123456789_826
Sandoval, Sarita
Rojas-Solorzano, L.
Gasbarri, Sandro
2015-12-07T09:02:36Z
2015-12-07T09:02:36Z
2005-06-20
Sarita Sandoval, Luis Rojas Solórzano, Sandro Gasbarri; 2005; Transient Two-Phase-Flow Model for Predicting Column Formation in Intermittent Gas Lift Systems; http://nur.nu.edu.kz/handle/123456789/887
http://nur.nu.edu.kz/handle/123456789/887
The major objective of this work is to generate a mathematical model, allowing the prediction of mixture density, liquid holdup, the pressure gradient in the pipe and the real column size. This is useful for optimizing cycle times and the amount of gas required to lift the fluids and to improve the diagnostic and simulation software of IGL wells
en
Research Subject Categories::TECHNOLOGY::Engineering mechanics
mechanical engineering
Transient Two-Phase-Flow Model for Predicting Column Formation in Intermittent Gas Lift Systems
Article
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