Nazarbayev University Repository (NUR) is an institutional electronic archive designed for the long-term preservation, aggregation, and dissemination of scientific research outcomes and intellectual property produced by the Nazarbayev University community and affiliated organizations.

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CONDUCTING POLYMER MATERIAL BASED ELECTRODES FOR WATER DESALINATION VIA CAPACITIVE DEIONIZATION
(Nazarbayev University School of Engineering and Digital Sciences, 2025-05-06) Duisenbekov, Sagydat
Capacitive deionization (CDI) is renowned for its economic viability, minimal energy usage, and environmental sustainability. Because of their stability and electrical conductivity, microporous carbons are a common component of traditional CDI electrodes. However, these materials usually have lower desalination capacities than more sophisticated alternatives like metal oxide composites, which have higher salt adsorption capacity (SAC) and are more energy-efficient. The focus of recent research has switched to investigating novel electrode materials to enhance the performance of CDI. Conducting polymers, such as polyaniline (PANI), are becoming more popular due to their flexible surface morphology, relatively higher conductivity and ion adsorption properties. BET surface area of AC/PANIF was around 1241 m2/g that is lower than AC's, which is 1282 m2/g, whereas AC/PANIH's was larger about 1350 m2/g. High pseudocapacitance from the addition of PANI nanofibers resulted in higher adsorption of Na+ and Cl- ions. According to the results, all the electrodes displayed capacitive behavior. The maximum specific capacitance was determined by the cyclic voltammetry (CV) curves: 73 and 71 F/g for the AC/PANIF, AC/PANIH and 39 F/g for the AC electrodes respectively. In addition, the wettability of the AC/PANIF electrode improved, decreasing by about 30 units. The AC/PANIF showed a higher capacity for salt adsorption, about 15 mg/g, than AC and AC/PANIH due to its improved functionality and CV properties.
ItemOpen Access
EFFICIENT COMPUTATIONAL APPROACHES TO GPU-BASED MONTE CARLO RADIATION TRANSPORT
(Nazarbayev University School of Engineering and Digital Sciences, 2025-04-24) Tair, Askar
This thesis focuses on efficient computational approaches for Monte Carlo Radiation Transport (MCRT) simulations using modern Graphics Processing Units (GPUs). Over the last decade, GPUs have become an important part of scientific computing due to their capability to perform large-scale parallel computations, particularly in areas such as radiation transport. Modern MCRT applications are complex simulations that require immense computational power. This work addresses the challenges and opportunities in using GPU architectures for the MCRT simulations and contributes to the understanding of how to optimize these simulations for better performance and energy efficiency. A detailed performance examination of several parallel pseudorandom number generators (PRNGs) running on various Nvidia GPU cards is presented in the thesis. MRG32k3a, MTGP32, PHILOX4_32_10, MT19937, and XORWOW are five PRNGs from the cuRAND library that are evaluated for their efficiency in producing uniform and non-uniform random numbers using a range of implementation options, including GPU-only, CPU-only, and hybrid CPU/GPU approaches. This assessment advances our knowledge of PRNG performance optimization on GPUs, particularly with regard to the Monte Carlo (MC) simulations. The thesis also evaluates two popular Python-based GPU programming platforms, CuPy and Numba, benchmarking against CUDA C for the MCRT simulations. This evaluation is based on performance and energy consumption using memory-intensive operations and compute-heavy problems. The analysis was conducted on Nvidia GeForce RTX3080, Tesla V100, and Tesla A100 GPU cards. It offers information about the advantages and disadvantages of these platforms, which is valuable to the scientific community when selecting tools for GPU-based simulations. Further, the work investigates the performance scaling of MCRT simulations on multiple GPUs, focusing on strong and weak scaling, optimization strategies such as fast math and block-thread configuration, and energy consumption. Using an Nvidia DGX-2 server with up to 10 GPUs, the study demonstrates how different scaling strategies and optimization techniques affect both performance and energy efficiency. This research provides practical recommendations for improving the use of multiple GPUs in large-scale MCRT simulations, contributing to the knowledge of multi-GPU programming and optimization. Overall, this thesis contributes to the understanding of how to efficiently run and optimize MCRT simulations on GPUs. It includes a detailed analysis of PRNGs performance, evaluates popular Python-based computing tools, and explores how well these platforms can scale their applications across multiple GPUs. This work provides useful insights for researchers, students, and professionals who work with GPU computing, particularly in the field of MCRT simulations.
ItemOpen Access
AN AUTOETHNOGRAPHIC INSIGHT INTO MULTILINGUAL DEVELOPMENT
(Nazarbayev University Graduate School of Education, 2024) Urazmetova, Perizat
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LABEL-FREE AND PROTEIN G-ENHANCED OPTICAL FIBER BIOSENSOR FOR DETECTION OF ALDH1A1 CANCER BIOMARKER
(Nazarbayev University School of Sciences and Humanities, 2025-04-25) Yegizbay, Zhandos
Cancer remains one of the leading causes of morbidity and mortality worldwide, highlighting the need for improved early detection strategies. Aldehyde dehydrogenase 1A1 (ALDH1A1) has emerged as a significant biomarker associated with tumor progression, chemoresistance, and poor prognosis in various cancers, including breast, lung, colorectal, prostate, and lymphoma. Current diagnostic methods for ALDH1A1, such as flow cytometry and ELISA, are limited by long detection times, the need for labeling, and reduced sensitivity in complex biological matrices. This study presents a novel optical fiber biosensor based on magnesium silicate nanoparticle-doped fibers for the label-free detection of ALDH1A1. The biosensor design incorporated protein G for enhanced antibody orientation and binding efficiency and anti-ALDH1A1 antibodies for specific recognition. Several sensor configurations were fabricated using a semi-distributed interferometer (SDI) format, and their performance was evaluated across a wide concentration range (10 fM–100 nM) in both phosphate-buffered saline (PBS) and fetal bovine serum (FBS). Our findings demonstrated that the inclusion of protein G significantly improved sensor sensitivity and reproducibility, achieving a limit of detection (LoD) of 172 fM in PBS. The sensor also maintained a positive response trend in FBS, indicating its potential applicability in clinically relevant samples. Furthermore, specificity testing confirmed the sensor's selectivity toward ALDH1A1, with negligible response to vascular endothelial growth factor (VEGF). This work introduces the first reported optical fiber biosensor for ALDH1A1 detection, offering a rapid, label-free, and highly sensitive approach suitable for future development in cancer diagnostics.
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AZA-ANNULATION REACTION FOR THE SYNTHESIS OF BIO-RELEVANT ALIPHATIC HETEROCYCLES
(Nazarbayev University School of Sciences and Humanities, 2025-04-30) Tetteh, Robert
Aza-heterocyclic compounds, particularly those with γ-lactams moiety, serve an important role in pharmaceuticals, agrochemicals, and materials science owing to their diverse biological application. Studies have shown that about 60% of drugs sold on the market contain azaheterocycles. Due to these important applications of aza-heterocyclic compounds, several strategies such as annulation, cyclization, cycloaddition, cycloisomerization, and fragmentation have been applied to synthesize different scaffolds of the heterocyclic compounds. However, aza-annulation is one of the simplest yet most efficient strategies for constructing aza-heterocycles since it enables rapid molecular complexity buildup, high diastereoselectivity, and minimal reaction steps. This research employed an aza-annulation reaction to construct aza-heterocyclic compound building blocks and investigated their diversification. The synthetic approach encompasses the condensation of ethyl acetoacetate with primary amines to generate enamines, followed by the aza-annulation with maleic anhydride to afford γ-lactams. Interestingly, the esterification of the carboxylic acid functionality in the aza-annulation product, followed by alkylation, resulted in a single product as a result of selective alkylation at the α-position to the γlactam for all the electrophiles (35-75%) except for iodobutane, which provided both alkylation of the enolate oxygen of the γ-lactam and the C-alkylation. The decarboxylation reaction of the aza-annulation products proceeded smoothly at 180-220 °C to afford two regioisomers (92%) in the ratio of 1:1, which upon alkylation with different electrophiles produced a single product (23-58%). In total, fourteen diversified scaffolds of the aza-heterocyclic compound have been constructed demonstrating a promising approach to accessing bio-relevant aza-heterocyclic scaffolds for future applications in pharmaceutical science.