School of Sciences and Humanities
http://nur.nu.edu.kz:80/handle/123456789/86
2024-03-28T20:51:17ZPPI_SNCP_AFM_COMPARSION
http://nur.nu.edu.kz:80/handle/123456789/7575
PPI_SNCP_AFM_COMPARSION
Nazir, Faisal
2023-01-01T00:00:00ZMODELING AND NUMERICAL ANALYSIS OF GRAPHENE MICROBEAM RESONATOR
http://nur.nu.edu.kz:80/handle/123456789/7373
MODELING AND NUMERICAL ANALYSIS OF GRAPHENE MICROBEAM RESONATOR
Yessetov, Yerkebulan
Microelectromechanical systems (MEMS) have emerged as a revolutionary technology,
enabling the development of miniaturized devices with diverse functionalities and
superior performance. Among the essential components of MEMS, microresonators
hold significant importance as they find applications in various fields, including mass
and force sensing, molecular detection, and nanoscale imaging. The quest to improve
the sensitivity and performance of microresonators has led researchers to explore novel
materials and innovative designs.
This thesis delves into the static and dynamic behavior of graphene cantilever
beam resonators under electrostatic actuation at their free tips. A rigorous analysis
of the system’s response was performed. The constitutive nonlinear equation of the
system was derived using the Energy method and Hamilton’s principle. An analytical
solution to the nonlinear static problem was obtained.
A lumped mass model was developed to study the essential dynamics of the
graphene cantilever beam. The generalized stiffness coefficient for the beam under
load at its tip was calculated, enabling a comprehensive analysis of its dynamic behavior.
A key focus was on investigating the dynamic pull-in conditions of the system
under both constant and harmonic excitation. Analytical predictions were validated
through numerical simulations. We observed that the system exhibited periodic solutions
when the excitation parameters 𝛼 and 𝜆 were below a certain separatix curve,
leading to sustained oscillations. On the other hand, if these parameters exceeded the
separatix curve, the system experienced pull-in instability, causing the beam to collapse.
Furthermore, we explored the impact of excitation frequency on the dynamic
response of the graphene cantilever beam under harmonic load. The simulations revealed
that choosing the excitation frequency near the beam’s resonant frequency
could lead to structural collapse under certain parameter conditions.
2023-07-01T00:00:00ZULTRASOUND-TRIGGERED NANO-FORMULATIONS FOR PREVENTION AND TARGETING OF BACTERIAL BIOFILMS
http://nur.nu.edu.kz:80/handle/123456789/7338
ULTRASOUND-TRIGGERED NANO-FORMULATIONS FOR PREVENTION AND TARGETING OF BACTERIAL BIOFILMS
Ganiyeva, Kamila
Prior to the antibiotic era, bacterial infections were the leading cause of death.
Antibiotics were developed to cure a variety of ailments and saved many lives. However, due
to overuse and inappropriate use of antibiotics, the emergence of bacterial resistance has
expedited the so-called "post-antibiotic age." As a result, increasing death rates due to resistant
bacterial infections a significant threat to public health and the world economies. The ability
of many bacterial strains to form biofilms is the leading cause of the high viability and spread
of the bacteria in tissues and chronic wounds. Modern antibiotics have shown low effectiveness
due to the impenetrable bacteria extra polymer substance (EPS) of the biofilm. In the present
thesis we explore a new strategy to target and prevent formation of drug-resistant bacterial
biofilm infections. We developed study, novel shellac/enzyme nanoparticle formulations of
three different enzymes (Alcalase, Savinase, Cellulase) and explored their ability to target
biofilms of S. epidermidis. Our idea is based on preventing the premature release of the enzyme
which can degrade the biofilm by depositing a silica shell over the nanocarrier particles that
covers the surface of sterically stabilized shellac core with encapsulated enzyme which plays a
role in the stimulus-triggered release of an active component to eradicate bacterial biofilms.
We assessed the quality of the formed silica shells using dynamic light scattering, Transmission
Electron Microscopy (TEM) and Energy-dispersive X-ray spectroscopy. TEM imaging
allowed to assess the thickness of the silica shell. We tested both uncoated and silica coated
shellac/enzyme nanoparticles in their effectiveness to degrade the bacterial biofilms. The most
efficient nano-formulations were TEOS-coated Cellulase-loaded shellac nanoparticles which
showed significant decrease in the residual biofilm biomass of S. epidermidis bacteria strain.
We observed a significant increase of the enzyme release from silica-coated enzyme
nanocarriers upon application of ultrasonic trigger, compared with non-coated enzyme
nanocarrier. Most of the additional amount of enzyme was released during and very shortly
after sonication. This demonstrated a successful ultrasonic trigger for the particles in the
biofilm. We also evaluated the cytotoxicity of these formulations where the results indicated
only a modest cytotoxicity on HeLa cell line which were used as a proxy for human cells. We
also did the same encapsulation by using (3-Aminopropyl)triethoxysilane (APTES) which lead
to similar results, but apparently higher cytotoxicity towards Hela cells. The developed silicaencapsulated
enzyme nanocarriers have the potential to prevent and target bacterial biofilm by
pretreating surfaces prone to bacterial biofilm infection and triggering the enzyme release by
application of medical grade ultrasound. The treatment of chronic wounds with such silica
shell-encapsulated enzyme-loaded nanoparticles could help develop more efficient ways of
removal of bacterial biofilm by using non-invasive techniques to improve patient outcomes.
2023-01-01T00:00:00ZHOW FEMALE UNIVERSITY STUDENTS IN KAZAKHSTAN EXPRESS THEIR FEMINIST IDENTITY IN DIFFERENT SOCIAL CONTEXTS: A QUALITATIVE STUDY BASED ON STUDENTS AT NAZARBAYEV UNIVERSITY
http://nur.nu.edu.kz:80/handle/123456789/7335
HOW FEMALE UNIVERSITY STUDENTS IN KAZAKHSTAN EXPRESS THEIR FEMINIST IDENTITY IN DIFFERENT SOCIAL CONTEXTS: A QUALITATIVE STUDY BASED ON STUDENTS AT NAZARBAYEV UNIVERSITY
Armsan, Rebekka
This research project examines the experiences which young women who study at Nazarbayev University (NU) and identify themselves as feminists encountered in different social contexts in Kazakhstan (unfamiliar/familial/university contexts), what they link their experiences to and what specific situations they have been in because of their feminist identity expression. Comparison of the experiences of female university students in familiar and new and unfamiliar social contexts provides insights into the ways in which feminist identity is negotiated and adapted in different settings, how and under which circumstances feminist identity of Kazakhstani women is revealed and concealed. To understand more about feminist identities in various social contexts the Identity Salience Theory will be applied to explain some of the processes related to revealing/concealing feminist identity.
2023-01-01T00:00:00ZNATIONALISM FROM THE MARGINS: A CRITICAL STUDY OF ELITIST HISTORIOGRAPHY AND POLITICS IN MĀWARĀʾ AL-NAHR AND KHURĀSĀN (LATER UZBEKISTAN, TAJIKISTAN AND AFGHANISTAN), 1800-1950.
http://nur.nu.edu.kz:80/handle/123456789/7329
NATIONALISM FROM THE MARGINS: A CRITICAL STUDY OF ELITIST HISTORIOGRAPHY AND POLITICS IN MĀWARĀʾ AL-NAHR AND KHURĀSĀN (LATER UZBEKISTAN, TAJIKISTAN AND AFGHANISTAN), 1800-1950.
Ahwar, Ahmad Javeed
This dissertation traces the history of national ideas in Māwarāʾ al-Nahr and Khurāsān, later known as Uzbekistan, Tajikistan, and Afghanistan, from the margins. This study follows the transformations of ideas of differences from the early nineteenth century when tribal, clan, sectarian, and regional affiliations prevailed in Māwarāʾ al-Nahr and Khurāsān to the time when Uzbek elites and Soviets in Bukhara, Khwārazm, and Russian Turkistan, and Pashtun nationalist elites in Kabul, laid the foundation of ethnonational-territorial identities of “Uzbek,” “Tajik,” and “Afghan,” and enforced boundaries between them. Furthermore, this dissertation pays particular attention to the de-Persianization projects (in the Bukharan People’s Soviet Republic/later Uzbek and Tajik SSRs and Afghanistan), which met with the insubordination of Tajiks.
The existing literature on nation-formation in Central Asia and Afghanistan is either written or indirectly influenced by elite sources. The prevalence of methodological nationalism has contributed to the reification of state-led and elitist nationalisms bearing the interests of the ruling groups in Uzbekistan, Tajikistan, and Afghanistan. Consequently, non-dominant/marginalized groups are represented as either passive or non-existent. Elite nationalism, backed by methodological nationalism, has contributed to the misrepresentation, misinterpretation, and erasure of the history of non-dominant/subaltern groups in the official national historiographies and politics of Māwarāʾ al-Nahr and Khurāsān (later Uzbekistan, Tajikistan, and Afghanistan). This dissertation aims to better understand “non-elite/non-dominant nationalisms” in these countries by bringing enormous materials to light, arguing that it is the elites’ manipulation and control of state resources, media, statistics, and their suppression of non-dominant languages and non-dominant language groups that ensure the triumph of “majority-formation” and early nationalization projects in Uzbekistan and Afghanistan. This dissertation approaches Tajik national consciousness from the position of “subalternity,” considering that Tajiks have been subjects of Uzbek and Afghan khanates for centuries and distinguishes Tajik consciousness from the formation of the Tajik SSR. It is also the dominance of pro-Uzbek Khujandī elites throughout the history of the Tajik SSR and their failure to promote the Tajik cause addressing the interests of Tajiks of the Uzbek SSR and Afghanistan, which adds to the marginality of the Tajik cause. Among other factors, the territorial and ideological constraints imposed by the Soviet regime, the indifference of Khujandī elites to the Tajik cause, and de-Persianization policies of the Uzbek SSR and Afghanistan contributed to the failure of Tajik national consciousness. The comparative and transnational perspective not only helps us rectify
iii
Anglo-Russian historiographies, which often separates Afghanistan from Central Asian studies but also challenges elitist historiographies that reduce discussions on the Tajik people to the territory of Tajikistan, leaving off the Tajiks of Uzbekistan and Afghanistan unattended.
Moreover, this study will place nationalist movements in broader historical and geographical contexts to explain how Tajik national consciousness failed and how Afghans and Uzbeks met with relative success. Furthermore, drawing upon the extensive research of primary sources such as court chronicles, local histories, Western travelogues, and the writings of leading pioneers of nationalism Maḥmūd Ṭarzī, Ṣadr al-Dīn ʿAynī, and ʿAbd al-Raʾūf Fiṭrat, this dissertation argues that the position of indigenous elitist sources (be it the feudal or nationalist one) towards non-dominant group is indistinguishable from the ruling class, pushing non-dominants to the margins. It is in European sources, in contrast to Edward Said’s notion of Orientalism, that non-dominant groups find a voice at times.
2023-01-01T00:00:00ZTO DIE OR NOT TO DIE—REGULATED CELL DEATH AND SURVIVAL IN CYANOBACTERIA
http://nur.nu.edu.kz:80/handle/123456789/7257
TO DIE OR NOT TO DIE—REGULATED CELL DEATH AND SURVIVAL IN CYANOBACTERIA
Barteneva, Natasha S.; Meirkhanova, Ayagoz; Malashenkov, Dmitry; Vorobjev, Ivan A.
Regulated cell death (RCD) is central to the development, integrity, and functionality
of multicellular organisms. In the last decade, evidence has accumulated that RCD is a universal
phenomenon in all life domains. Cyanobacteria are of specific interest due to their importance in
aquatic and terrestrial habitats and their role as primary producers in global nutrient cycling. Current
knowledge on cyanobacterial RCD is based mainly on biochemical and morphological observations,
often by methods directly transferred from vertebrate research and with limited understanding of
the molecular genetic basis. However, the metabolism of different cyanobacteria groups relies on
photosynthesis and nitrogen fixation, whereas mitochondria are the central executioner of cell death
in vertebrates. Moreover, cyanobacteria chosen as biological models in RCD studies are mainly
colonial or filamentous multicellular organisms. On the other hand, unicellular cyanobacteria have
regulated programs of cellular survival (RCS) such as chlorosis and post-chlorosis resuscitation.
The co-existence of different genetically regulated programs in cyanobacterial populations may
have been a top engine in life diversification. Development of cyanobacteria-specific methods for
identification and characterization of RCD and wider use of single-cell analysis combined with
intelligent image-based cell sorting and metagenomics would shed more light on the underlying
molecular mechanisms and help us to address the complex colonial interactions during these events.
In this review, we focus on the functional implications of RCD in cyanobacterial communities.
2022-01-01T00:00:00Z