Engineering Commons^™

Metakaolin-Based Geopolymer Concrete; Synthesis, Development And Characterization, Heba Fouad

Theses and Dissertations

Geopolymers are rendered as an essential sustainable replacement to the widely used Ordinary Portland Cement (OPC) which causes immense carbon dioxide emissions, hence a detrimental impact on society’s health and the environment. Geopolymers are three-dimensional networks of polymerized tetrahedral silicate and aluminate in the form of Q4(4Al), Q4(3Al) and Q4(2Al) which act as the principal binding phase in concrete. Past research has reported the synthesis of geopolymers from different aluminosilicates precursors, their characterization, and their wide range properties. However, previous studies still have not properly investigated effective range of synthesis ratios for a particular source material, optimum curing regimes, short- …

Liquid-Cooled Thermoelectric Modules: Potential For Efficient Water Harvesting Through Air Condensation, Bowo Yuli Prasetyo, Aindri Yuliane, Parisya Premiera Rosulindo, Fujen Wang

Makara Journal of Technology

Water is one of the essential natural resources for the sustaining life of all beings on this planet. In general, groundwater is used to meet daily needs, although the availability of this water source becomes a major concern, particularly in some areas with limited access to it. Air condensation is a solution for providing water in such areas. This study aims to explore the potential of utilizing the thermoelectric technology as an alternative solution for water provision. An experiment is conducted using a system consisting of single liquid-cooled thermoelectric cooling devices/modules (TECs). Three types/variants of TECs with different cooling capacities …

Smart Materials For Noise And Vibration Damping In High-Speed Rail Systems: A Comparative Analysis, Hyginus Chidiebere Onyekachi Unegbu, Danjuma Saleh Yawas, Bashar Dan-Asabe, Abdulmumin Akoredeley Alabi

Makara Journal of Technology

Effective noise and vibration control remains a critical challenge in high-speed rail systems, directly influencing passenger comfort and the longevity of infrastructure. This study evaluated four advanced materials—piezoelectric materials, shape memory alloys (SMAs), magnetorheological (MR) fluids, and damping composites—focusing on their potential for mitigating noise and vibration in high-speed rail applications. A combination of experimental and simulation-based analyses was employed to assess these materials based on their noise reduction coefficient, vibration transmissibility ratio, thermal stability, and durability under varying environmental conditions. The findings revealed that damping composites and SMAs demonstrated superior performance, offering enhanced noise attenuation and vibration control compared …

Impact Of Compaction Process On The Carbon Epoxy Composite Under Varied Environmental Conditions, Maryam Al Kuwaiti, Amir Hussain Idrisi, Asima Zahoor, Mostafa S. Elsayed, Dinu Thomas Thekkuden, Abdel-Hamid I. Mourad

Michigan Tech Publications

Fibre-reinforced polymeric composites utilized in aerospace settings, experience varying environmental conditions throughout their operational lifespan. The major factors that can have adverse effects on their long-term performance are water and temperature. The present study investigates how the determinants such as water and temperature impact the structural integrity of plain weave woven carbon/epoxy laminated composites and further categorizing them into compacted and non-compacted groups. The compacted group involves in-process compactions during composite lay-up and the use of bleeders/breathers around the laminate, whereas the non-compacted group lacks these procedures. Specimens comprising twelve plies are created and submerged in water heating chambers set …

Nano-Second Pulsed Laser Ablation Of Inconel 718 And Mmpcd For Simultaneous Optimal Ablation Rate And Surface Quality, Ahmed Elkaseer, Islam Abdelgaliel, Jon Lambarri, Iban Quintana, Steffen Scholz, Mohamed Aly

Mechanical Engineering

This study investigates the ablation performance of Inconel 718, a nickel-based superalloy, and metalmatrix polycrystalline diamond (MMPCD), a super composite, using a nano-second (ns) pulsed laseracross a range of ablation conditions. Single trenches varying in energy fluence and scanning speedswere created, analyzing the experimental responses in terms of ablation rate and surface roughness.Using regression techniques, models were developed to understand these relationships. Four multi-objective optimization algorithms, weighted value grey wolf optimizer (WVGWO), multi-objectivePareto search (MOPS), multi-objective genetic algorithm (MOGA), and multi-objective sunfloweroptimization (MOSFO), were employed to optimize these models. Key findings include MMPCDachieving the highest ablation rates at maximum fluence …

Quantitative Analysis Of Machine Learning Model Performance And The Need To Consider Explainability, Vishnu S. Pendyala

Open Educational Resources

This presentation, titled "Quantitative analysis of Machine Learning model performance and the need to consider explainability," delves into various metrics used for evaluating machine learning models. It thoroughly examines fundamental classification metrics like accuracy, precision, recall, and F-score, while also discussing more advanced measures such as the Kappa Statistic and Matthews Correlation Coefficient (MCC), particularly highlighting their relevance in scenarios with imbalanced datasets. The presentation underscores the importance of model accuracy in real-world applications and briefly introduces regression metrics like R-squared and F-statistic. Additionally, it addresses challenges related to data imbalance and fairness in ML models, stressing the critical need …

Experimental Insights Into Friction Losses Of Post-Tensioned Precast Full-Scale Girders, Mostafa Serry

Theses and Dissertations

The use of post-tensioning in construction has revolutionized the construction industry and made way for several construction and structural applications that were unattainable before. One of the most important topics that are synonymous with the use of post-tensioning is the matter of accurately calculating the short-term and long-term losses that arise in pre-stress. One of the prominent types of losses is the friction losses that occur during the jacking of the concrete elements due to its impact on structural integrity and longevity.

The thesis examines this critical aspect of friction losses in post-tensioned concrete structures. The study focuses on full-scale, …

Synergic Efficiency Of Organophosphonates In The Synthesis And Corrosion Inhibition Of Zinc Complexonates, Shoyunus Botir Ugli Obidov, Xusniddin Nurboboyevich Raximov, Xasan Irgashevich Kadirov, Satridin Maxamatdinovich Turabdjanov

Technical science and innovation

In this article, the processes of metal complex synthesis are studied in detail. Zinc OEDF+NTF complexation reactions were carried out in the presence of polyhydric alcohols, ethylene glycol, glycerol, and citric acid. For the first time, the synergistic efficiency of a mixture of zinc OEDF+NTF complexes with methyldiethanolamine, used as an inhibitor of mineral salt accumulation, was studied. It was found that when selecting the components in equivalent amounts, the inhibition efficiency of the composition is at least 90%. The high efficiency of inhibiting mineral salt accumulation in the composition is due to the presence of methyldiethanolamine, alkylimidazoline, and their …

Application Of Satellite Interferometry To Tailings Damages To Determine Their Stability, Mukhlisa Khasanovna Rakhimova

Technical science and innovation

In our country and abroad, the construction of special alluvial hydraulic structures - tailings storage facilities - is being carried out on a large scale for storing waste from the mineral enrichment process, the operation of which requires ensuring and observing strict technological control, failure of which leads to serious accidents and even disasters. Tailings dams play a critical role in the mining and metallurgy industry by providing safe storage of production waste. However, their stability and safety are a constant concern. Satellite interferometry (InSAR) is an innovative technology that can effectively monitor deformations and changes in the condition of …

Mathematical Model Of Control Of A Pumping Unit Used In The Technological Process Of Wastewater Treatment, Nodira Batirdjanovna Alimova Dsc, Professor, Aziza Ruzimamamovna Khaitova

Technical science and innovation

Strict environmental and health regulations, as well as the cost-effectiveness of wastewater treatment processes, have made control technology an important priority in the wastewater treatment industry. Control strategies operate on input variables (setpoint values) by choosing the values they should take to influence the evolution of state variables so that output variables (controllable variables) achieve desired values. The object is a pumping unit used in wastewater treatment technology, and its mathematical model is a set of structures reflecting the characteristics of the simulated processes. The main parameters in mathematical models are temperature and vibration level during pump operation, coordinates of …

Energy-Efficient Technologies For Drying Mulberry Silkworm Cocoons Using Infrared Radiation, Doston Ishmukhammat Ugli Samandarov

Technical science and innovation

The article presents the results of theoretical and experimental studies on drying of mulberry silkworm cocoons. Based on the analysis of drying efficiency and silk quality, the use of infrared radiation (IR) at a temperature of 70 °C was found to be optimal. The experimental data were tested on six mathematical models, among which the Midilli model most accurately described the drying process. The effective moisture diffusion coefficient was found to vary in the range of 1.847×10^-⁹-4.339×10^-⁹ m²/s, and the drying rate was found to be 0.32-0.79 kg of water/hour. IR radiation promotes accelerated evaporation of …

Enhancing Dynamic Impact Mechanical Properties Of Ultra-High-Performance Concrete With Steel Fiber Reinforcement, Oybek Valijonovich Tuyboyov, Sultonmurod Bekpulatovich Normatov

Technical science and innovation

This study investigates the dynamic impact mechanical properties of Ultra-High-Performance Concrete (UHPC) with high-content and directional reinforced steel fiber. The research explores the influence of directional distributed steel fiber on the dynamic impact properties of UHPC specimens prepared with varying fiber contents. Through experimental analysis using the split-Hopkinson pressure bar (SHPB) method, stress-strain curves, stress peaks, dynamic increase factor (DIF), and ductile energy absorption properties of the specimens at different strain rates were obtained. The results demonstrate that oriented steel fiber significantly enhances the dynamic properties of UHPC, with notable improvements in peak strain, peak stress, and energy absorption capacity. …

Energy Saving Technology For Drying Garlic (Allium Sativum), Jasur Esirgapovich Safarov, Shakhnoza Abduvaxitovna Sultanova, А M. Mirkomilov

Technical science and innovation

Food drying is a widely used preservation method aimed at reducing water content to extend shelf life, decrease weight, and enhance storage efficiency. This process, particularly in garlic, involves rapid initial moisture loss followed by a slower phase due to the increasing difficulty of extracting residual water. Drying methods include natural solar drying and advanced mechanical techniques such as hot air and vacuum drying, each influencing product quality, drying efficiency, and economic feasibility. Dehydrated garlic exhibits specific sensory, physico-chemical, and microbiological characteristics, making it suitable for various applications, including powder production. Advanced drying equipment optimizes air volume, temperature, and material …

Development Of An Effective Container Design That Reliably Provides Isolation Of Water Inflow And Elimination Of Well Flooding, Tolib Olimovich Komilov Suffix, Sherali Hallokovich Umedov, Anvarkhoja Akbarkhodjayevich Rakhimov

Technical science and innovation

Currently, the hydrocarbon extraction industry is one of the most high-tech and rapidly developing sectors globally. The primary priority of this industry is to improve the technical and economic indicators of drilling and well operation. A particularly pressing issue is reducing well waterlogging and effectively isolating water flows, which contributes to optimizing hydrocarbon resource development. The introduction of modern equipment into production processes increases the demand for hydrocarbon resources, further complicating the challenges faced by the industry. This article highlights the relevance of applying innovative technologies to address well complications. Specifically, a new technology for isolating water flows and eliminating …

Development Of The Principles Of Forming A Database For Geoinformation Mapping Of Tourism (As An Example Of Bostanlyk District Of Tashkent Region), Lola Xoji-Akbarovna Gulyamova, Risolat Raximjon Qizi Nizomova

Technical science and innovation

When creating tourist assessment maps for the purpose of tourist mapping, special attention is paid to determining the criteria for the formation of a database. To assess tourism opportunities in terms of natural conditions, ecology and socio-economic factors, data collection, their characteristics and requirements for them were studied. In order to improve the quality of sources of tourist assessment maps, parables of working with the internet and real-time removable data, creating a map based on social network data were considered. Proposals were made to create, manage and maintain a big data base. The ArcGIS program analyzed the possibilities of describing …

Bаsing Thе Sресifiс Сhаrасtеristiсs Оf Sаlinе Sоils Оn Thе Bаsis Оf Buildings Аnd Struсturеs In Thе Соnditiоns Оf Uzbеkistаn (Аs Аn Еxаmрlе Оf Thе Mirzасhоl Рlаins), Аbdubaki Djalilovich Kауumоv, Murad Kаmbаrоv, Olmos Zafarov, Zukhriddin Muradov, Islom Ilhom Ugli Ro‘Ziyev

Technical science and innovation

This article comprehensively examines the physical-mechanical and chemical properties of saline soils and their changes under the influence of moisture, as well as the impact of these changes on the foundations of buildings and structures. The study analyzes the variation of salinity levels over time due to prolonged water exposure and its effects on the stability and safety of structures, highlighting critical issues observed in regions of our country where saline soils are prevalent. Based on engineering-geological and hydrogeological research, solutions to minimize the consequences of salinity, determine soil deformation and strength characteristics, and ensure the safety of structures are …

Joint Assessment Of Characteristics Of Object Parameters And Statistical Characteristics Of Disturbing Influences, Yulduz Mukhtarkhodzhaevna Abdurakhmanova

Technical science and innovation

The paper considers the problem of joint estimation of object parameters and statistical characteristics of random disturbances based on data from independent experiments. It is indicated that the use of the method of moments for the problem under consideration gives estimates that are not effective in the Rao-Kramer sense and the most common asymptotically effective estimation method, in this sense, is the maximum likelihood method(ML). However, in the case of objects with several disturbances that have distribution densities of a general form, the implementation of the ML method is difficult, since to find the values of the distribution density it …

Qualitative Analysis Of The Circuits Of Autonomous Inverters With Shut-Off Valves, Shukhrat Badreddinovich Umarov

Technical science and innovation

The article presents the results of a qualitative analysis of circuits of autonomous current and voltage inverters with cut-off valves; the influence of the charge value of the switching capacitor in parallel and series equivalent circuits on the restoration of the switching properties of the thyristors of the inverter power circuit is studied. It is shown that due to the energy periodically accumulated in the inductive elements of the load, the voltage on the switching capacitor in the cut-off state is greater than in a conventional parallel autonomous current inverter. This circumstance ensures an increase in the switching stability of …

Determination Of Techno-Economic Indicators Of Pumped Storage Power Plants Under The Operational Conditions Of The Tuyamuyun Hydro Complex, Kurbon Salikhdjanovich Dzhuraev, Abdurauf Abduaziz Uulu, Fotima Tulkunovna Shadibekova

Technical science and innovation

The article presents the results of research on the analysis of the state of the electric power system of the Republic of Uzbekistan, taking into account the operating modes of hydraulic and thermal power plants with the study of the sharp-peak nature of the electric load in the winter and summer periods of the year and the problems of covering daily load schedules due to a lack of maneuverable capacities. The use of pumped storage power plants is proposed to cover and smooth daily load schedules across months and seasons. The necessity of utilizing the capacity of pumped storage power …

Method For Calculating Characteristic Frequency Ab (Rechargeable Batteries), Alisher Ganisher Ugli Bozorov

Technical science and innovation

A method for calculating the characteristic frequency is proposed, based on automatic interpolation of the frequency dependence of the reactance and subsequent calculation of the characteristic frequency as one of the roots of the interpolation function. The developed algorithm allows you to calculate the characteristic frequency from only 4 points of the frequency dependence of the reactance. In this case, the error in calculating the resonant frequency parameter does not exceed ~2 Hz.

Obviously, the values of the coefficients of the equation depend on the number of resistance values X and the corresponding frequencies of the test signal. The indicated …

Dendrite-Free Strategies For Aqueous Zinc-Ion Batteries: Structure, Electrolyte, And Separator, Gang Wu, Wu-Hai Yang, Yang Yang, Hui-Jun Yang

Journal of Electrochemistry

Continued growth in energy demand and increased environmental pollution constitute major challenges that need to be addressed urgently. The development and utilization of renewable, sustainable, and clean energy sources, such as wind and solar, are crucial. However, the instability of these intermittent energy sources makes the need for energy storage systems increasingly urgent. Aqueous zinc-ion batteries (AZIBs) have received widespread attention due to their unique advantages, such as high energy density, cost-effectiveness, environmental friendliness, and safety. However, AZIBs face significant challenges, mainly the formation of zinc dendrites that seriously affect the stability and lifetime of the batteries, leading to battery …

Electrochemical-Method-Induced Strong Metal-Support Interaction In Pt-Cnt@Sno2 For Co-Tolerant Hydrogen Oxidation Reaction, Shen-Zhou Li, Zi-Jie Lin, Qi-An Chen, Zhao Cai, Qing Li

Journal of Electrochemistry

Inducing the classic strong metal-support interaction (SMSI) is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles (NPs) with supports. Conventional thermal reduction method for inducing SMSI processes is often accompanied by undesirable structural evolution of metal NPs. In this study, a mild electrochemical method has been developed as a new approach to induce SMSI, using the cable structured core@shell CNT@SnO₂ loaded Pt NPs as a proof of concept. The induced SnO_x encapsulation layer on the surface of Pt NPs can protect Pt NPs from the poisoned of CO impurity in …

Contributions To Journal Of Electrochemistry, The Flagship Journal Of Chinese Chemical Society Electrochemical Committee, Will Be Listed As A New Recommendation Policy For China Youth Awards Of Electrochemist, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

On Resource Testing Of Straight-Bevel Gears In Drive Mechanisms Of Cotton Machines, Shoraxmat Asqarovich Shaabidov, Umid Mamazokir Ugli Mamasobirov, Azizbek G‘Ulom O‘G‘Li Xusanbayev

Technical science and innovation

This article is dedicated to endurance testing of straight-tooth bevel gear reducers used in various machines, including cotton farming machinery. The choice of the test object is due to the fact that many machines require bevel gear transmissions for spatial arrangement of components. These gears enable the transmission of rotational motion between intersecting shaft axes within compact external dimensions. Additionally, bevel gear transmissions are the most common type of gear mechanisms after cylindrical ones.

For several objective reasons, straight-tooth bevel gears have gained wide use. Unlike cylindrical gears, they are more sensitive to manufacturing and assembly errors as well as …

All-Solid-State Sodium-Ion Batteries: A Leading Contender In The Next-Generation Battery Race, Rui-Jie Zhu, Ze-Chen Li, Wei Zhang, Akira Nasu, Hiroaki Kobayashi, Masaki Matsui

Journal of Electrochemistry

All-solid-state lithium-ion batteries (LIBs) using ceramic electrolytes are considered the ideal form of rechargeable batteries due to their high energy density and safety. However, in the pursuit of all-solid-state LIBs, the issue of lithium resource availability is selectively overlooked. Considering that the amount of lithium required for all-solid-state LIBs is not sustainable with current lithium resources, another system that also offers the dual advantages of high energy density and safety— all-solid-state sodium-ion batteries (SIBs) —holds significant sustainable advantages and is likely to be the strong contender in the competition for developing next-generation high-energy-density batteries. This article briefly introduces the research …

Enriched Microbial Consortia From Natural Environments Reveal Core Groups Of Microbial Taxa Able To Degrade Terephthalate And Terphthalamide, Laura G. Schaerer, Sulihat Aloba, Emily Wood, Allison Olson, Isabel B. A. Valencia, Rebecca Ong, Stephen Techtmann

Michigan Tech Publications

Millions of tons of polyethylene terephthalate (PET) are produced each year, however only ~30% of PET is currently recycled in the United States. Improvement of PET recycling and upcycling practices is an area of ongoing research. One method for PET upcycling is chemical depolymerization (through hydrolysis or aminolysis) into aromatic monomers and subsequent biodegradation. Hydrolysis depolymerizes PET into terephthalate, while aminolysis yields terephthalamide. Aminolysis, which is catalyzed with strong bases, yields products with high osmolality, which is inhibitory to optimal microbial growth. Additionally, terephthalamide, may be antimicrobial and its biodegradability is presently unknown. In this study, microbial communities were enriched …

Polyaxial Stress-Dependent Tensorial Permeability Variations Of A Columnar Jointed Rock Mass: Insights From 3d Distinct Element Method, Prasad Pothana, Vamegh Rasouli, Kegang Ling

Petroleum Engineering Student Publications

Stress-induced permeability changes in geological formations have implications for various geo-engineering applications. Fractures are the predominant fluid flow pathways within tight geological formations such as jointed basaltic rock mass. Three-dimensional permeability variations of a columnar jointed rock mass using the three-dimensional block distinct element method are investigated. First, a permeability tensor is constructed by simulating fluid flow through joint sets using cubic law and determining its principal components through eigenvector analysis. Subsequently, numerical simulations are conducted to gain insights into the impact of principal stresses on joint deformation and fluid flow. Joint deformation is controlled by the joint’s mechanical properties, …

Influence Of Fused Deposition Modeling Process Parameters On The Constitutive Model Of Hyperelastic Thermoplastic Polyurethane, Lucas Gallup, Mohamed Trabia, Brendan O'Toole, Youssef Fahmy

Mechanical Engineering Faculty Research

Thermoplastic polyurethanes (TPUs) are suited for fused deposition modeling (FDM) of parts that require high levels of flexibility and strength. Predicting the deformation of TPU parts produced using FDM may be difficult, especially under large deformations, as their constitutive models depend on the printing process parameters. The lack of understanding led to the absence of constitutive models for TPU parts produced using FDM. This work aims to identify accurate hyperelastic constitutive models. Six groups of uniaxial tensile specimens were produced using FDM. These groups were made with variations in two process parameters, which were infill geometry and extrusion nozzle temperature. …

A Comparative Study Between Soft Structures And Hard Structures For The Protection Of Egypt’S Coastlines Against Climate Change, Donia Eldwib

Theses and Dissertations

Coastal communities worldwide face unprecedented threats from climate change, with rising sea levels, increased storm intensities, and accelerated coastal erosion posing significant risks. Egypt, with over 3,000 kilometers of coastlines along the Mediterranean and Red Seas, it is particularly vulnerable due to its densely populated and economically critical low-elevated coastal zones. With the Mediterranean Sea, and the Nile Delta specifically under huge threats, this study examines the different coastal protection strategies used to address these climate change impacts. Different coastal protection structures have been used throughout the years starting with the well-known hard structures moving on to greener alternatives such …

Commingling Production Of Deep Coal-Measure Gas Through Hydraulic Fracturing: Propagation Patterns Of Induced Fractures And Their Determinants, Chen Hao, Li Guozhang, Qin Yong, Wang Jianguo, Shen Jian, Sun Yuqi, Yuan Erjun, Li Dian

Coal Geology & Exploration

Objective The commingling production of coal-measure gas represents a pivotal approach to enhancing the single-well production of unconventional gas in China. However, coal-measure gas reservoirs exhibit distinctly different material compositions and physical properties, leading to uncertainty of the propagation modes and developmental degrees of fractures in different reservoirs during the hydraulic fracturing of coal-measure gas reservoirs subjected to commingling production. Therefore, effectively coordinating the stimulation of multiple reservoirs for multi-gas commingling production is crucial for minimizing production costs and maximizing production capacity. Methods This study investigated the Linxing block along the northeastern margin of the Ordos Basin as an example …