7264 research outputs found
Sort by
ELECTROMAGNETIC WAVE INTERACTIONS WITH MULTIPLE ARBITRARILY SHAPED NANOTUBES
No full textThis work studies the interaction of electromagnetic waves with arbitrarily shaped nanotubes. The research starts with the analysis of cylindrical-shaped nanotubes, due to their simplicity, further replacing them with arbitrary-shaped nanotubes for the same conditions. In this work, the objective is to increase the concentration of the electric field inside pairs of nanotubes by optimizing their shape appropriately. The Isogeometric-
Analysis-based Boundary Element Method (IGABEM) approach was used to achieve the objective in pair with optimization approaches involving gradient-based and guided random search methods. This combination of mathematical programming with an appropriate parametric model, for the accurate modeling of free-form boundaries, and the IGABEM
method for the shapes’ performance evaluation was successful in identifying the optimal
shape of nanotubes. So far obtained results show a substantial increase in the concentration of electric field inside the shape-optimized nanotubes. A field concentration increase of more than 20 times compared to circular nanotubes was achieved and minimization showed 57 times decrease. Furthermore, the optimized shapes showed a better field concentration over a wide range of EM wave orientations and distances between nanotubes. This result demonstrates the robustness of the obtained results and their potential applicability in a wide range of applications
EVALUATION OF ML INFERENCE WORKLOADS ON REDUCED REFRESH RATE DRAM
No full textThis thesis investigates the potential benefits of reducing DRAM refresh rates to improve the performance of Machine learning and Neural Network inference workloads. The increasing integration of ML and NN models in various industries makes it necessary to optimize these models to efficiently use computing resources, particularly in devices with limited capabilities. To maintain data integrity, DRAM requires periodic refresh cycles, which has a substantial impact on power consumption and system efficiency. Thus, DRAM refresh rates can be lowered for performance purposes. While this study does not add any additional components to the memory controller, other proposed approaches had hardware or software overhead. Preliminary findings indicate that NNs have a remarkable tolerance to data loss, caused by reduced refresh rates. Results show that DRAM refresh rates can be reduced by up to 15-150 times the usual refresh rate without significant impact on NN accuracy. Additionally, NNs showed 2.7% faster inference and consumed 5.6% less power at refresh rate of 1 second
MICROWAVE HEATING OF THE GEOPOLYMERS IN A CONSTRUCTION 3D PRINTER
No full textThis MSc research thesis delves into the mechanical behavior of copolymer-based structures fabricated through 3D printing, specifically focusing on the transformative influence of microwave heating. Centered on geopolymers, recognized for their eco-friendly and sustainable attributes, the study aims to elucidate the nuances in stress and deformation dynamics introduced by microwave heating in the 3D printing process.
A comprehensive literature review outlines the various applications of microwave heating within geopolymer chemistry, advancements in 3D printing technology, and materials science. This review synthesizes the concepts to establish a theoretical framework, enabling a deep understanding of the intricate interactions between the application of microwave energy and geopolymerization processes.
Empirical data were collected through stress-strain experiments conducted on geopolymer samples subjected to microwave heating and conventional 3D printing techniques. This investigative approach required meticulous experimentation and systematic modification of parameters such as treatment duration, microwave energy exposure period, and the resultant voltage-strain profiles. These parameters were scrutinized to ascertain the impact of microwave heating on the mechanical performance of geopolymer structures.
Findings from stress and strain tests provide reliable insights. It was observed that microwave heating alters the polymerization process, thereby influencing the material's response to external forces. A comparative analysis of stress-strain curves between specimens exposed to microwave radiation and those treated conventionally reveals differences in structural integrity and load-bearing capacities.
Discussions elucidate these findings, pondering the implications for construction methodologies. Microwave heating emerges as a promising catalyst for enhancing the mechanical performance of geopolymer-based constructions. This revelation holds the potential to refine procedures for 3D printing recyclable building materials, optimizing them for better performance and sustainability
Қалдықтарды суды тазарту үшін адсорбент ретінде тұрақты түрде қайта пайдалану
No full textOrganic compounds present in polluted wastewater exhibit stability during treatment. Methylene blue, an organic pollutant known for its hazardous oxidative properties, is of particular concern as it is commonly found in the effluent from the textile industry, and its presence in the environment threatens the biosphere. Given the stability of methylene blue dye, sorption via biochar materials emerges as a viable pathway for remediation. Biochar, derived from waste materials such as straw flax and sewage sludge through pyrolysis, is an effective medium. This approach addresses waste management concerns and aligns with the principles of circular economy and environmentally friendly practices. The scope of this work is to study the adsorption properties of biochar from sewage sludge or straw flax in removing methylene blue from water. The working concentration of methylene blue (MB) in water was 20 ppm. Biochar was characterised by various techniques such as Scanning Electron Microscopy, Thermogravimetric Analysis, Fourier Transform Infrared Spectroscopy, and X-ray Diffraction. The biochar efficiency as an adsorbent was proved by the MB removal of 77.33% achieved after 30 min for 220 mg of straw flax-derived biochar with particle size in the 100-400 μm range. Using the sewage sludge-derived biochar (220 mg, 100 μm < d < 400 μm), an MB removal of 30.86% was achieved after 30 min. The straw flax biochar (100 μm < d < 400 μm) showed the lowest thermal tolerance, as 65.71% of it retained its weight at 800 oC in the N2 environment. Biochar with particle size distribution ranging in 100-400 μm was more effective than particle sizes in 400-800 μm. The maximum adsorption efficiency observed was 84.37%, and it was achieved by 220 mg of the straw flax biochar with particle size in the range of 100-400 µm after 2 hours. The significance of this investigation lies in its innovative approach to repurposing waste materials generated from pyrolysis for the treatment of water contaminated with the organic dye methylene blue, aligning with the principles of the circular economy
THE DISTRIBUTION OF RELATIVE CLAUSES IN KAZAKH CONVERSATIONS
No full textIn conversation, speakers need to track the referents they introduce, establishing their identity and thereby building common ground with the hearer. This communicative need can be achieved through relative clauses (RCs), among other linguistic means. While most studies have traditionally focused on the formal syntactic properties of RCs, either in a language-specific or cross-linguistic perspective, other studies in usage-based model of language have focused on the variation of RCs in naturally occurring discourse, including conversations. These studies suggest that the distribution of RCs in naturally occurring discourse is affected by a number of linguistic, cognitive, and discourse-related factors such as word order, information flow, markedness, humanness status of the referent in the head noun phrase, and functions of RCs, among others.
Under the framework of Discourse and Grammar, I focus on relative clause constructions in the Kazakh language and explore the skewed distributional patterns of RCs as influenced by a number of linguistic, cognitive, and discourse-related factors that govern communication. Through the analysis of approximately 300 minutes of naturally occurring informal conversations from the Multimedia Corpus of Modern Spoken Kazakh, I have found that the distribution of relative clauses in Kazakh conversations exhibits statistically significant skews. I argue that these skewed patterns are best predicted by the interplay of the semantic factor of Humanness, the cognitive factor of Information Status as well as the grammatical factor of Function of the RC.
The findings support the view that discourse is always driven by the communicative goals of interactants, and that, consequently, grammar is a crystallization of such recurrent linguistic behavior. As such, this work corroborates the importance of studying linguistic structures in their ‘social habitat’ — everyday social interactions. Most importantly, this study contributes to a holistic representation of Kazakh, whose grammatical descriptions, as of now, are mostly based on introspection, written language, and idealized language use, with only few works analyzing spoken data from fieldwork interviews
COMPUTABILITY OF ALGEBRAIC STRUCTURES
No full textIn the modern world, research areas are extremely progressive. One of
them is the computability of structure within the computability theory.
As the research field progressed, we got new problems. In the com-
putability of structures, the actual problem was efficient. To fill this gap
in the paper "Algebraic structures computable without delay", the au-
thors defined fully primitive recursive structures. Then, in 2019 in the
paper "Foundations of Online Structure Theory" the authors defined a
new research area "online structures" and renamed the fully primitive
recursive structures as punctual structures. In this work, I presented a
comprehensive survey of all available articles on punctually computable
structures
GREEN PATHWAYS TO PRODUCE CARBAMIDE
No full textUrea is an organic compound with a very high demand among fertilizers. It has been produced industrially for many decades; however, since toxic ammonia is required for its production, new green methods need to be implemented with respect to the environment and new stricter environmental legislation.
This report offers a rigorous design of an industrial urea plant operating through Stamicarbon technology located in Kazakhstan. Apart from the synthesis process, the operation includes wastewater treatment and carbon dioxide recovery. In comparison with other available technologies, this method implements low-pressure recovery of carbon dioxide, resulting in an energy-efficient and more environmentally friendly process.
Throughout this report, the work on significant equipment design has been done using a variety of methods, including shortcut and Kern methods for heat exchanger units such as scrubber, stripper, and film condenser, rules of thumb for a reactor, and the application of principles of fluid mechanics and transport phenomena for the prilling tower. The general minor equipment design was prepared using the values from the process simulation in ASPEN PLUS V14. The plant's location was decided to be in a special economic zone ”Aktau Seaport”, next to the "KazAzot" JSC, after analyzing economic, environmental, geographical, and other site considerations. An analysis of the environment and waste streams was conducted to ensure the ecological safety of our process in accordance with the Environmental Code of the Republic of Kazakhstan. The plant's operation and construction proved to be profitable through the estimation of purchased equipment costs, production costs, and revenues using APEA computer tools, cost escalation, historical data, and other techniques.
The proposed design for an industrial urea plant in Kazakhstan, utilizing Stamicarbon technology and incorporating efficient waste management and carbon dioxide recovery, underscores the feasibility of achieving both ecological safety and profitability in fertilizer production
DEVELOPMENT OF A FLIGHT SIMULATOR
No full textThis project’s aim is the development of a virtual flight simulator (VFS) to predict the trajectory of a model plane undergoing free pitch motion in a wind tunnel. The project incorporates the design and building of a model plane with a pitch rotation degree of freedom, the development of a VFS for plotting the real-time flight trajectory in LabVIEW using the Hardware-in-a-Loop approach, and the evaluation of the performance of the model and VFS developed by conducting three experiments assessing flight behavior. The model design was completed based on the longitudinal static stability and steady-level flight analyses via XFLR5 and an in-house code using MATLAB. This study integrated advanced aerodynamic testing systems, including the ATI Mini 40 sensor and Arduino BLE Sense 33, within a wind tunnel setting to capture and analyze real-time data.
Three experiments were conducted to assess the model and VFS: the accelerating flight mode assessing the thrust required to fly at the desired velocity, the effect of the pitch trim angle on the flight trajectory in x- and z-axis directions, and the steady-level flight mode assessing the relation between the flight velocity and the plane pitch trim angle. The first experiment showed the same trend as results calculated numerically using mathematical models for aerodynamic parameters and the XFLR5 wing-only based analysis. However, the experimental drag coefficient and thrust required to fly at the desired velocity were about a hundred times higher than the numerical estimations since the numerical estimations considered drag from the wing only, while, in reality, there were additional sources of drag such as the fuselage, motors, propellers, and the support system. The second experiment resulted in the expected flight trajectory with a higher pitch trim angle resulting in a higher altitude increase, which complies with the flight mechanics laws. The third experiment showed an unexpected result that was justified as even though it is expected for a conventional plane that the trim angle reduces as the flight velocity increases, the plane model developed in this project had unconventional thrust vectoring that may have added a non-linear effect, which caused the opposite trend. To evaluate the given justification, further studies are needed. In general, the experiments showed plausible results. Thus, the developed VFS can be used for complex and unconventional aircraft models for educational purposes and future pilot training
THE ROLE OF MEDIUM OF INSTRUCTION IN FUNCTIONAL LITERACY IN KAZAKHSTAN: A COMPARATIVE, INFERENTIAL, AND VALUE-ADDED ANALYSIS
No full textThe medium of instruction has been a controversial issue in Kazakhstan as the two main mediums (Kazakh and Russian) have had unequal status due to a unique historical context. During the Soviet era, Kazakh medium schools faced severe restrictions and funding cuts, while Russian medium schools were deliberately prioritized and provided effective functioning. Although Kazakh medium schools have been supported since independence, the perceptions of inferiority surrounding the Kazakh sector may persist. Such perceptions may arise not only from Soviet ideologies but also from the Programme for International Student Assessment (PISA), which found that the Russian sector outperformed the Kazakh sector in functional literacy across all cycles. However, PISA has a major limitation as it is a one-time assessment. To offer a broader picture, this quantitative research utilized unique data from the Centre for Pedagogical Measurements (CPM), which conducted large-scale assessments on the same population of students and schools in April 2021 and January 2022, testing their reading, scientific literacy, and mathematical literacy proficiencies across several oblasts of Kazakhstan. Employing advanced educational modeling techniques, this research made three interconnected studies. The first comparative Rasch modeling study found that Russian medium students had significantly higher ability estimates at two time points. The second multilevel modeling study revealed that Russian medium predicts achievement in reading and scientific literacy and growth in achievement in reading literacy. While these studies found the superior performance of the Russian sector, the third VAM study found that some Kazakh medium groups significantly and practically added the highest value to students’ mathematical and scientific literacy abilities, while Russian medium groups added the lowest value to scientific literacy abilities. The research findings imply that while Kazakh sector may broadly need help in materials and resources, the Ministry of Education should provide targeted, research-based support for both mediums of instruction
QUANTITATIVE ASSESSMENT OF THE IMPACT OF MINING ACTIVITIES ON THE ENVIRONMENT IN THE ULYTAU REGION USING GEOSPATIAL APPROACH
No full textThe topic of "Quantitative assessment of the impact of mining activities on the environment in the Ulytau region using geospatial approach" was chosen due to the urgent need to understand and quantify the environmental impact of mining activities in the Ulytau region. While geospatial approach provides a systematic and quantitative method for analyzing environmental impacts of mining activities, which can be helpful for effective environmental management and sustainable resource extraction.
The objective of this thesis is to conduct a comprehensive quantitative assessment of the impact of mining activities on the environment in the Ulytau region using a geospatial approach. This includes quantification of mining activities in the region, estimation of area impacted by the mining activities, and assessment of its impacts on the local environment. Also, it includes produced maps with mining locations.
The research approach involves understanding of the negative impacts of mining on the environment from the literature, and involves understanding of tools utilized for geospatial technology to monitor and analyze the Ulytau region. Also, application of geospatial approach includes utilization of Google Earth and QGIS softwares for satellite imagery, and Excel for data quantification. Moreover, besides providing the methodology for geospatial assessment, the thesis proposes international practices and experience of other countries and considers regulatory framework.
The quantitative analysis on 51 mining activities has shown notable increase in the mining activities in the Ulytau region. During the study period from 2004-2011 to 2023, it shows an increase from 91.133 km2 to 114.874 km2, or 26.1%, or 23.742 km2 in absolute values. These conclusions show the importance of a geospatial approach that can assist in quantification of areas affected by the mining activities, and it can be implemented for sustainable mining practices and effective environmental management strategies to mitigate negative impacts of mining. It shows the need for implementation of modern technologies associated with the Fourth Industrial Revolution, since it can assist in sustainable and environmentally friendly business.
For future research, it is recommended to continue utilizing geospatial approaches for monitoring and assessment of mining activities. Additionally, research efforts should focus on exploring other available remote sensing technologies, and it should include application of machine learning, and artificial intelligence to improve data analysis capabilities. Also, further research should be done assessing existing environmental regulations and enforcement mechanisms. Moreover, further research should include access to more comprehensive and detailed data sources to enhance accuracy and depth of analysis