Center for Energy and Advanced Materials Science

Center for Energy and Advanced Materials Science

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Open Access
SYNTHETIC AMPHOTERIC CRYOGELS AS AN ANTIDOTE AGAINST ACUTE HEAVY METAL POISONING
(MDPI, 2021-12-15) Baimenov, Alzhan; Fakhradiyev, Ildar; Berillo, Dmitriy; Saliev, Timur; Mikhalovsky, Sergey; Nurgozhin, Talgat; Inglezakis, Vassilis J.
The effectiveness of an amphoteric cryogel (AAC) as an oral sorbent (enerosorbent) for the treatment of acute poisoning of small animals (rats) with heavy metals (HMs) was studied in in vivo experiments. The morphological structure of the cryogel was examined using scanning electron microscopy/energy-dispersive X-ray analysis and confocal microscopy. The use of the cryogel in the treatment of rats administered an LD50 dose of Cd(NO3)2, CsNO3, Sr(NO3)2, or HgCl2 in aqueous solution showed their high survival rate compared to the control group, which did not receive such treatment. The histological and chemical analysis of internal tissues and the biochemical analysis of the blood of the experimental animals showed the effectiveness of the cryogel in protecting the animals against the damaging effect of HMs on the organism comparable with unithiol, a chelating agent based on 2,3-dimercapto-1-propane sulfonic acid sodium salt (DMPS) approved for the treatment of acute poisoning with some heavy metals. Keywords: cryogel; antidote; DMPS; elimination; heavy metals
Open Access
BIOMASS-DERIVED POROUS CARBON FROM AGAR AS AN ANODE MATERIAL FOR LITHIUM-ION BATTERIES
(MDPI, 2021-12-22) Issatayev, Nurbolat; Kalimuldina, Gulnur; Nurpeissova, Arailym; Bakenov, Zhumabay
New porous activated carbons with a high surface area as an anode material for lithium-ion batteries (LIBs) were synthesized by a one-step, sustainable, and environmentally friendly method. Four chemical activators—H2SO4, H3PO4, KOH, and ZnCl2—have been investigated as facilitators of the formation of the porous structure of activated carbon (AC) from an agar precursor. The study of the materials by Brunauer–Emmett–Teller (BET) and scanning electron microscopy (SEM) methods revealed its highly porous meso- and macro-structure. Among the used chemical activators, the AC prepared with the addition of KOH demonstrated the best electrochemical performance upon its reaction with lithium metal. The initial discharge capacity reached 931 mAh g−1 and a reversible capacity of 320 mAh g−1 was maintained over 100 cycles at 0.1 C. High rate cycling tests up to 10 C demonstrated stable cycling performance of the AC from agar.
Open Access
A MINI-REVIEW ON RECENT DEVELOPMENTS IN ANTI-ICING METHODS
(MDPI, 2021-11-27) Kenzhebayeva, Adelya; Bakbolat, Baglan; Sultanov, Fail; Daulbayev, Chingis; Mansurov, Zulkhair
An aggressive impact of the formed ice on the surface of man-made objects can ultimately lead to serious consequences in their work. When icing occurs, the quality and characteristics of equipment, instruments, and building structures deteriorate, which affects the durability of their use. Delays in the adoption of measures against icing endanger the safety of air travel and road traffic. Various methods have been developed to combat de-icing, such as mechanical de-icing, the use of salts, the application of a hydrophobic coating to the surfaces, ultrasonic treatment and electric heating. In this review, we summarize the recent advances in the field of anti-icing and analyze the role of various additives and their operating mechanisms.
Open Access
ASSESSMENT OF BIOCLIMATIC CHANGE IN KAZAKHSTAN, END 20TH-MIDDLE 21ST CENTURIES, ACCORDING TO THE PRECIS PREDICTION
(Public Library of Science, 2020-10-02) Lopez Fernandez, Maria Luisa; Zhumabayev, Dauren; Marco Garcia, Ricardo; Baigarin, Kanat; Lopez Fernandez, Maria Soledad; Baisholanov, Saken
We evaluate bioclimatic changes in Kazakhstan from the end of the 20th century until the middle of the 21st century to offer natural resource managers a tool that facilitates their decision-making on measures to adapt agriculture and environmental care to foreseeable climate change. We use climatic data from the “Providing REgional Climates for Impact Studies” (PRECIS) prediction and study them following the Worldwide Bioclimatic Classification System (WBCS) of Rivas-Martínez. For three 25-year intervals (1980–2004, 2010–2034 and 2035–2059), we identify the continentality, macrobioclimates, bioclimates, bioclimatic variants, thermotypes, ombrotypes and isobioclimates of the study area. The results of the work allow us to: locate the territories where bioclimatic conditions will change, quantify the magnitude of the predicted climate changes, and determine the trends of predictable climate change. We present the results in maps, tables and graphs. For the 80-year interval, we identify 3 macroclimates, 3 bioclimatic variants, 10 bioclimates, 11 thermotypes, 10 ombrotypes and 43 isobioclimates. Some of those found bioclimates, thermotypes, ombrotypes and isobioclimates are only located in the E, SE and S mountains, where they occupy very small areas, that decrease in a generalized way as the 20th century progresses. Comparing the three successive periods, the following trends are observed: 36.2% of the territory increases in thermicity; 7.3% of the territory increases in continentality; 9.7% of the territory increases in annual aridity; 9.5% of the territory increases in summer aridity or mediterraneity; and generalized losses occur in the areas of all mountain isobioclimates. The climate change foreseen by the PRECIS model for the middle of the 21st century leads to bioclimatic homogenization, with 20.8% losses in bioclimatic diversity. We indicate on maps the locations of all the predicted bioclimatic changes; these maps may provide decision makers with a scientific basis to take necessary adaptation measures.
Open Access
EVALUATING SULFUR-COMPOSITE CATHODE MATERIAL WITH LITHIATED GRAPHITE ANODE IN COIN CELL AND POUCH CELL CONFIGURATION
(Frontiers Media, 2020-11-09) Uzakbaiuly, Berik; Mentbayeva, Almagul; Konarov, Aishuak; Kurmanbayeva, Indira; Zhang, Yongguang; Bakenov, Zhumabay
High-performance sulfur-composite cathode material, sulfur/polyacrylonitrile/ketjen black, was prepared by simple mixing and low-temperature heat treatment route. The cell made of the composite cathode and anode from metallic lithium or lithiated graphite was assembled in coin cell configuration. Half-cells retained about 70% of their initial capacity of 1,270 mAh g−1 after 150 cycles, while full-cells retained about 85% of the initial capacity of 1,500 mAh g−1 for over 150 cycles. Since coin cells do not reflect the true performance of a practical cell, the cathode composite was assembled with lithiated graphite anode in a 45 × 85 × 6 mm3 pouch cell configuration. This cell retained about 81% of its initial capacity for over 100 cycles. At high cycling rates up to 1 C, the pouch cell demonstrated a moderate rate capability and exhibited good recovery and stable performance after high rate cycling. Also, the cell successfully passed safety tests such as overcharge, deep discharge, and mechanical short circuit tests.
Open Access
Facile Synthesis of Binder-Free Three-Dimensional CuxS Nanoflowers for Lithium Batteries
(Frontiers Media, 2020-07-16) Adylkhanova, Assyl; Nurpeissova, Arailym; Adair, Desmond; Bakenov, Zhumabay; Taniguchi, Izumi; Kalimuldina, Gulnur
Copper sulfides (CuxS) with different stoichiometry are considered as prospective cathode materials for lithium batteries owing to their large energy storage capability. In this work, three-dimensional CuxS cathodes were synthesized via introducing commercially available copper foam into the solution of dimethyl sulfoxide (DMSO) and sulfur powder. The synthesis procedures were straightforward and ultrafast and did not require additional reagents, high temperature, or long processing time and can be considered as a facile one-step method. Copper sulfide materials with different stoichiometry (x = 1.8, 1.96) were obtained by changing the temperature and the residence time of the copper foam in the DMSO solution. The effects of the temperature and time on phase and morphology of CuxS were characterized by X-ray diffraction and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. Electrochemical tests resulted in a stable cyclability of Cu1.8S cathode with 100% Coulombic efficiency and capacity of approximately 250 mAh g–1.
Open Access
Calculation of Water Wheel Design Parameters for Micro Hydroelectric Power Station
(EDP Sciences, 2019-05-29) Kodirov, Dilshod; Tursunov, O
This paper is devoted to the issues such as modelling the design parameters and operating modes and improving the design of micro hydroelectric power plants operating in low-pressure water flow. Taking into consideration above-mentioned issues, it is possible to increase the efficiency of using low-pressure water energy systems. The main dimensions of the water wheel of a micro hydropower plant depend on the water flow velocity v, water volume Q, acting at a fixed point in time on the water wheel blade, and also on the depth of the water level H.
Open Access
Lithographically defined synthesis of transition metal dichalcogenides
(IOP Publishing, 2019-09-30) Kemelbay, Aidar; Kuntubek, Aldiyar; Chang, Nicholas; Chen, Christopher T; Kastl, Christoph; Inglezakis, Vassilis J.; Tikhonov, Alexander; Schwartzberg, Adam M; Aloni, Shaul; Kuykendall, Tevye R.
Transition metal dichalcogenides (TMDs) promise to revolutionize optoelectronic applications. While monolayer exfoliation and vapor phase growth produce extremely high quality 2D materials, direct fabrication at wafer scale remains a significant challenge. Here, we present a method that we call 'lateral conversion', which enables the synthesis of patterned TMD structures, with control over the thickness down to a few layers, at lithographically predefined locations. In this method, chemical conversion of a metal-oxide film to TMD layers proceeds by diffusion of precursor propagating laterally between silica layers, resulting in structures where delicate chalcogenide films are protected from contamination or oxidation. Lithographically patterned WS2 structures were synthesized by lateral conversion and analyzed in detail by hyperspectral Raman imaging, scanning electron microscopy and transmission electron microscopy. The rate of conversion was investigated as a function of time, temperature, and thickness of the converted film. In addition, the process was extended to grow patterned MoS2, WSe2, MoSe2 structures, and to demonstrate unique WS2/SiO2 multilayer structures. We believe this method will be applicable to a variety of additional chalcogenide materials, and enable their incorporation into novel architectures and devices.
Open Access
Crystallographic Characterisation of Ultra-Thin, or Amorphous Transparent Conducting Oxides—The Case for Raman Spectroscopy
(MDPI, 2020-01-07) Ainabayev, Ardak; Sugurbekova, Gulnar; Caffrey, David; Zhussupbekova, Ainur; Vijayaraghavan, Rajani K.; Kaisha, Aitkazy; Shvets, Igor V.; Fleischer, Karsten
The electronic and optical properties of transparent conducting oxides (TCOs) are closely linked to their crystallographic structure on a macroscopic (grain sizes) and microscopic (bond structure) level. With the increasing drive towards using reduced film thicknesses in devices and growing interest in amorphous TCOs such as n-type InGaZnO 4 (IGZO), ZnSnO 3 (ZTO), p-type Cu x CrO 2 , or ZnRh 2 O 4 , the task of gaining in-depth knowledge on their crystal structure by conventional X-ray diffraction-based measurements are becoming increasingly difficult. We demonstrate the use of a focal shift based background subtraction technique for Raman spectroscopy specifically developed for the case of transparent thin films on amorphous substrates. Using this technique we demonstrate, for a variety of TCOs CuO, a-ZTO, ZnO:Al), how changes in local vibrational modes reflect changes in the composition of the TCO and consequently their electronic properties.
Open Access
Characterization of tar generated from the mixture of municipal solid waste and coal pyrolysis at 800 °C
(Elsevier, 2020-03-02) Tursunov, O; Suleimenova, B; Kuspangaliyeva, Botagoz; Anthony, E.J.; Sarbassov, Yerbol
Nowadays, comprehensive perception of the tar characteristics generated from municipal solid waste (MSW) and coal to guide pyrolysis or gasification gas yield upgrading and cleaning has attracted massive research attention. In this study, MSW and coal samples were chosen as principal components. The mixture of these products was pyrolyzed in a horizontal tube furnace at 800 °C with a heating rate of 20 °C/min. The tar derived from the pyrolysis of this mixture was further studied. Gas chromatography–mass spectrometry (GC–MS)coupled with a trace GC and a nuclear magnetic resonance (NMR) spectrometer was applied to investigate the tar composition and characterization along with their molecular chemical structures. 1H and 13C NMR spectra indicated that the functional groups of the tar derived from the mixture of MSW and coal were dominant at the resonances of 0.9–1.8 ppm, 1.5–2.6 ppm and 3.8–4.1 ppm for 1H, 10–40 ppm and 60–80 ppm for13C. The results from GC–MS showed that the tar derived from the mixture of MSW and coal contained about 20 major chemical compounds such as benzene, methyl isobutyl, toluene, xylene, phenol, cresol, naphthalene and others.
Open Access
Survey on Household Solid Waste Sorting at Source in Developing Economies: A Case Study of Nur-Sultan City in Kazakhstan
(MDPI, 2019-11-18) Sarbassov, Yerbol; Sagalova, Tolkyn; Venetis, Christos; Xenarios, Stefanos; Inglezakis, Vassilis
The exponential population growth in urban areas makes existing solid waste management policies and strategies challenging. The situation becomes more strenuous in fast-growing cities where increasing waste production can hardly be met by the capacity of existing facilities. Practices like waste prevention, recycling, reuse, and recovery are fundamental elements needed for the reduction of solid waste disposed in landfills, especially in fast-growing cities where more sustainable management practices need to be adopted. This study investigated the behavioral attitudes of citizens of the capital of Kazakhstan, Nur-Sultan (former Astana), towards household solid waste disposal and separation at the source. The survey was conducted through stratified random sampling during April and July of 2018 with the participation of 3281 respondents. It is the first attempt, to our knowledge, of assessing recycling trends in Kazakhstan from the household perspective. The results showed that 24% of respondents were already sorting household solid waste despite the absence of a separation system at the source. The study further demonstrated that separation at source could be effective if the local authorities were to introduce sound public awareness campaigns and install recycling bins in close proximity to residential buildings
Open Access
Crystallographic Characterisation of Ultra-Thin, or Amorphous Transparent Conducting Oxides—The Case for Raman Spectroscopy
(MDPI, 2020-01-07) Caffrey, David; Zhussupbekova, Ainur; Vijayaraghavan, Rajani K.; Ainabayev, Ardak; Kaisha, Aitkazy; Sugurbekova, Gulnar; Shvets, Igor V.; Fleischer, Karsten
The electronic and optical properties of transparent conducting oxides (TCOs) are closely linked to their crystallographic structure on a macroscopic (grain sizes) and microscopic (bond structure) level. With the increasing drive towards using reduced film thicknesses in devices and growing interest in amorphous TCOs such as n-type InGaZnO4 (IGZO), ZnSnO3 (ZTO), p-type CuxCrO2, or ZnRh2O4, the task of gaining in-depth knowledge on their crystal structure by conventional X-ray diffraction-based measurements are becoming increasingly difficult. We demonstrate the use of a focal shift based background subtraction technique for Raman spectroscopy specifically developed for the case of transparent thin films on amorphous substrates. Using this technique we demonstrate, for a variety of TCOs CuO, a-ZTO, ZnO:Al), how changes in local vibrational mo
Open Access
Atomic Force Microscopy Study of Cross-Sections of Perovskite Layers
(EURASIAN CHEMICO-TECHNOLOGICAL JOURNAL, 2019) Migunov, D.; Eidelman, K.; Kozmin, A.; Saranin, D.; Ermanova, I.; Gudkov, D.; Alekseev, A.
Improvement of methods for imaging of the volume structure of photoactive layers is one of the important directions towards development of highly efficient solar cells. In particular, volume structure of photoactive layer has critical influence on perovskite solar cell performance and life time. In this study, a perovskite photoactive layer cross-section was prepared by using Focused Ion Beam (FIB) and imaged by Atomic Force Microscopy (AFM) methods. The proposed approach allows using advances of AFM for imaging structure of perovskites in volume. Two different types of perovskite layers was investigated: FAPbBr(3) and MAPbBr(3). The heterogeneous structure inside film, which consist of large crystals penetrating the film as well as small particles with sizes of several tens nanometers, is typical for FAPbBr(3). The ordered nanocrystalline structure with nanocrystals oriented at 45 degree to film surface is observed in MAPbBr(3). An optimized sample preparation route, which includes FIB surface polishing by low energy Ga ions at the angles around 10 degree to surface plane, is described and optimal parameters of surface treatment are discussed. Use of AFM phase contrast method provides high contrast imaging of perovskite structure due to strong dependence of phase shift of oscillating probe on materials properties. The described method of imaging can be used for controllable tuning of perovskite structure by changes of the sample preparation routes....
Open Access
Techno-economic modellingto strategize energyexportsinthe Central AsianCaspian region
(Heliyon, 2017-03-27) Bakdolotov, Aidyn; De Miglio, Rocco; Akhmetbekov, Yerbol; Baigarin, Kanat
This paper studies the concept of energy security from export-oriented countries’ point ofview. It aims to test the effects of long-term energy export strategies in the Central Asian Caspian(CAC) region,by exploring the trade-offs between a “risk” indicator and some key variables of the energy system such as the total cost,the quantities exported, and the corresponding revenues.Risk reduction goals are combined with securing a minimum level of revenues from the hydrocarbon exports goals. It is also attempted to provide a definition and aquantification of a risk indicator on the basis of four components. The analysis makes use of a techno-economic energy system model to quantitatively evaluate the response of the energy sector to energy security risks,and it ssensitivity to different export strategies.
Open Access
Named Entity Recognition for Kazakh Using Conditional Random Fields / Извлечение именованных сущностей из текста на Казахском языке с использованием условных случайных полей
(The 4-th International Conference on Computer Processing of Turkic Languages “TurkLang 2016”, 2016) Gulmira, Tolegen; Alymzhan, Toleu; Zheng, Xiaoqing
We addressed the Named Entity Recognition (NER) problem for the Kazakh language by using conditional random fields. Kazakh is a typical agglutinative language in which thousands of words could be generated by adding prefixes and suffixes to the same root, which arises a serious data sparsity problem for many NLP tasks. To reduce the data sparsity problem, a necessary preprocessing step is to split the words into their roots and morphemes by morphological analysis. In this study, we designed a CRF-based NER system for Kazakh, which leveraged the features derived from the results of a new-developed morphological analyzer, and found that the performance can be boosted by introducing such derived features. Moreover, we assembled a NER corpus which was manually annotated with location, organization and person names.
Open Access
Initial Experiments on Russian to Kazakh SMT
(Research in Computing Science 117, 2016) Myrzakhmetov, Bagdat; Makazhanov, Aibek
We present our initial experiments on Russian to Kazakh phrase-based statistical machine translation. Following a common approach to SMT between morphologically rich languages, we employ morphological processing techniques. Namely, for our initial experiments, we perform source-side lemmatization. Given a rather humble-sized parallel corpus at hand, we also put some effort in data cleaning and investigate the impact of data quality vs. quantity trade off on the overall performance. Although our experiments mostly focus on source side preprocessing we achieve a substantial, statistically significant improvement over the baseline that operates on raw, unprocessed data.
Open Access
Thermal Management of Lithium/Sulphur Cells Using a Simple 2D Model
(Modern Environmental Science and Engineering (ISSN 2333-2581). Academic Star Publishing Company, 2016., 2016-04) Ismailov, Kairat; Massalin, Yerzhan; Bakenov, Zhumabay; Adair, Desmond
Lithium sulphur (Li/S) batteries are currently receiving significant attention as an alternative power source for zero-emission vehicles and advanced electronic devices due to the very high theoretical specific capacity of the sulphur cathode. Here a simple 2D transient method for the simulation of thermal characteristics of a lithium/sulfur cell is developed. The method is capable of determining the transient response of the thermal field. The heat sources associated with charging and discharging are estimated from experimental data and used as boundary conditions, and the simulations are performed at different charge and discharge current rates. The simulations were carried out for natural cooling.
Open Access
A simple approach to synthesize novel sulfur/graphene oxide/multiwalled carbon nanotube composite cathode for high performance lithium/sulfur batteries
(Ionics. Springer-Verlag Berlin Heidelberg 2016, 2016-04-30) Yuan, Guanghui; Zhao, Yan; Jin, Huafeng; Bakenov, Zhumabay
A sulfur/graphene oxide/multiwalled carbon nanotube (S/GO/MWNT) composite was synthesized via a simple ultrasonic mixing method followed by heat treatment. By taking advantage of this solution-based self-assembly synthesis route, poisonous and noxious reagents and complicated fabrication processes are rendered unnecessary, thereby simplifying its manufacturing and decreasing the cost of the final product. Transmission and scanning electronic microscopy observations indicated the formation of the threedimensional interconnected S/GO/MWNTcomposite through the environmentally friendly process...
Open Access
Exploring 3D microstructural evolution in Li-Sulfur battery electrodes using in-situ X-ray tomography
(www.nature.com/scientificreports, 2016-09-17) Yermukhambetova, Assiya; Tan, Chun; Daemi, Sohrab R.; Bakenov, Zhumabay; Darr, Jawwad A.; Brett, Daniel J. L.; Shearing, Paul R.
Lithium sulfur (Li-S) batteries offer higher theoretical specific capacity, lower cost and enhanced safety compared to current Li-ion battery technology. However, the multiple reactions and phase changes in the sulfur conversion cathode result in highly complex phenomena that significantly impact cycling life. For the first time to the authors’ knowledge, a multi-scale 3D in-situ tomography approach is used to characterize morphological parameters and track microstructural evolution of the sulfur cathode across multiple charge cycles. Here we show the uneven distribution of the sulfur phase fraction within the electrode thickness as a function of charge cycles, suggesting significant mass transport limitations within thick-film sulfur cathodes. Furthermore, we report a shift towards larger particle sizes and a decrease in volume specific surface area with cycling, suggesting sulfur agglomeration. Finally, we demonstrate the nano-scopic length-scale required for the features of the carbon binder domain to become discernible, confirming the need for future work on in-situ nano-tomography. We anticipate that X-ray tomography will be a powerful tool for optimization of electrode structures for Li-S batteries.
Open Access
Fabrication and Properties of Carbon- Encapsulated Cobalt Nanoparticles over NaCl by CVD
(Nanoscale Research Letters, 2016-09-27) Li, Haipeng; Li, Yue; Zhang, Yongguang; Liang, Chunyong; Wang, Hongshui; Li, Baoe; Adair, Desmond; Bakenov, Zhumabay
Carbon-encapsulated cobalt (Co@C) nanoparticles, with a tunable structure, were synthesized by chemical vapor deposition using Co nanoparticles as the catalyst and supported on a water-soluble substrate (sodium chloride), which was easily removed by washing and centrifugation. The influences of growth temperature and time on the structure and magnetic properties of the Co@C nanoparticles were systematically investigated. For different growth temperatures, the magnetic Co nanoparticles were encapsulated by different types of carbon layers, including amorphous carbon layers, graphitic layers, and carbon nanofibers. This inferred a close relationship between the structure of the carbon-encapsulated metal nanoparticles and the growth temperature. At a fixed growth temperature of 400 °C, prolonged growth time caused an increase in thickness of the carbon layers. The magnetic characterization indicated that the magnetic properties of the obtained Co@C nanoparticles depend not only on the graphitization but also on the thickness of the encapsulated carbon layer, which were easily controlled by the growth temperatures and times. Optimization of the synthesis process allowed achieving relatively high coercivity of the synthesized Co@C nanoparticles and enhancement of its ferromagnetic properties, which make this system promising as a magnetic material, particularly for high-density magnetic recording applications.