Mechanical Engineering Commons^™

Dying Of Natural Silk Deglued By Various Methods, Venera Djavdatovna Khamidova

Technical science and innovation

Products made of natural silk are indispensable for their hygienic properties and will always be in great demand. To obtain an even and intense coloration on a textile material, it is necessary to ensure its effective preparation with the most complete removal of hydrophobic contaminants (both natural and silicone oils applied during the weaving process, lubricants, etc.), which hinder the dyeing of the substrate and reduce the color characteristics of the obtained colors. Therefore, the issue of preparing natural silk for dyeing is relevant. In view of the sensitivity of the main fiber-forming component of natural silk - fibroin to …

Selective Oxidation Of Iron In Chalcopyrite For Enhanced Copper Recovery, Khojiakbar Shuxrat O'G'Li Sultonov, Shokhrukh Toshpulatovich Khojiev, Gulnoza Berdiyor Qizi Beknazarova, Malika Sayfullayevna Saidova

Technical science and innovation

This study explores the thermodynamic feasibility of selectively oxidizing iron contained in chalcopyrite mineral while preventing the oxidation of copper sulphide, with the ultimate goal of enhancing the copper concentration in the sulphide concentrate. A redox reaction in the solid phases between chalcopyrite and copper (I) oxide was constructed and subjected to thermodynamic analysis. The research identifies a crucial temperature range of 498-598 K (225-325 °C) as the most favourable for the redox reaction. The equilibrium constants at the selected optimal temperatures, 1.152 for chalcopyrite and 1.137 for copper (I) oxide, indicate that the redox reaction adheres to the expected …

Solving Water Resources Problems - Water Saving In The Republic Of Uzbekistan, Rustam Muxammatdjanovich Raximov

Technical science and innovation

In this article we will talk about the problems of water resources in the Republic of Uzbekistan. The problem of drinking water supply, solutions to provide drinking water to the population of Uzbekistan. The largest consumers of fresh water in Uzbekistan are farmers. Due to outdated infrastructure, 40% of water is wasted. Rising food prices and the risk of spreading disease are the first signs of water shortages that we may experience in the coming еars. Uzbekcosmos told how to solve the problem. Water is an invaluable resource used not only in the home, but also in the production and …

Modelling Of Heat Transfer In An Air Solar Collector, Shakhnoza Abduvaxitovna Sultanova, Jasur Esirgapovich Safarov, A.A. Mambetsheripova

Technical science and innovation

This study is the prediction, depending on time and different geographical and climatic situations, of different operating parameters: solar radiation, ambient and outlet coolant temperature, heat exchange coefficients and losses. All these determine, in the absence of measurements, the efficiency of the system modelled with existing models with respect to these parameters. These models are usually compared with experimental results. Before modelling, it is necessary to investigate the different heat transfer and exchange regimes that exist between the different elements of this system in order to eventually have a system of equations governing this exchange. The modelling principle is to …

A Study On The Influence Of Cutting Parameters On Surface Roughness And Visualization Through Contour Plots And 3d Surface Profiles, Zayniddin Nosirovich Muxiddinov

Technical science and innovation

This research investigates the intricate relationship between cutting parameterscutting speed, feed rate, and depth of cut and surface roughness in machining processes. Surface roughness is a key determinant of machined surface quality, and optimizing cutting parameters is crucial for achieving superior finishes. Employing advanced visualization techniques, including contour plots and 3D surface profiles, the study offers a comprehensive exploration of surface topography dynamics. Statistical analyses and regression modeling enhance the quantitative understanding of how cutting parameters interact to shape surface roughness. The research affirms the significant influence of cutting speed, feed rate, and depth of cut, providing practical insights for …

Theory Of Development And Improvement Of The Mathematical Model Of The Methodology Of Public Control In The Management Of Occupational Safety And Industrial Risks, Aliakbar Khamidullaevich Rasulev, Sunnatilla Suleymanovich Suleymanov, Nodira Bakhadirzhanovna Gaibnazarova

Technical science and innovation

The article develops and analyzes a mathematical model based on a logical flowchart of the methodology of public control in the management of occupational safety and industrial risks and probability theory, according to the model, the results of compliance with the requirements of social cooperation on occupational safety lead to a sharp increase in the probability of reliability, management efficiency becomes higher. Analysis of the mathematical model of the developed logical flowchart based on probability theory has shown that when the parties cooperate to monitor the results of compliance with labor protection requirements, they lead to a sharp increase in …

Research Of The Influence Of Dust On Photovoltaic Modules, Anvarjon Mirolimov, Xalmurat Iliev

Technical science and innovation

The influence of dust concentrations on the current-voltage characteristics (voltampere characteristics) of photovoltaic modules (PVM) based on crystalline silicon in laboratory conditions. It was investigated how an uncleaned panel affects the output power. The tests were carried out in the city of Tashkent on the territory of the “National Research Institute of Renewable Energy Sources”. The objects were located co-plurally as specified in GOST R 60904-1 Photoelectric devices. Part 1. Measurement of current-voltage characteristics. Measurements of a cleaned photovoltaic module with a maximum power of 330 W and not a cleaned one of 236 W were obtained. Based on the …

Synthesis And Characterization Of Titanium Nitride–Carbon Composites And Their Use In Lithium-Ion Batteries, Helia M. Morales Ramirez, Horacio Vieyra, David A. Sanchez, Elizabeth M. Fletes, Michael Odlyzko, Timothy P. Lodge, Victoria Padilla-Gainza, Mataz Alcoutlabi, Jason Parsons

Mechanical Engineering Faculty Publications

This work focuses on the synthesis of titanium nitride–carbon (TiN–carbon) composites by the thermal decomposition of a titanyl phthalocyanine (TiN(TD)) precursor into TiN. The synthesis of TiN was also performed using the sol-gel method (TiN(SG)) of an alkoxide/urea. The structure and morphology of the TiN–carbon and its precursors were characterized by XRD, FTIR, SEM, TEM, EDS, and XPS. The FTIR results confirmed the presence of the titanium phthalocyanine (TiOPC) complex, while the XRD data corroborated the decomposition of TiOPC into TiN. The resultant TiN exhibited a cubic structure with the FM3-M lattice, aligning with the crystal system of the synthesized …

Small Scale Wave Energy Convertor For Remote Applications, Rafael Torres Rodriguez, John Stephenson, Max Mailloux-Beauchemin, Brandon Nguyen, Ryan Chang

Mechanical Engineering Senior Theses

The following thesis showcases the yearlong culmination of a senior design project focused on the development of a small-scale wave energy generator intended to provide consistent and sustainable energy for remote marine environments. This project’s main customers include, but are not limited to, the National Oceanic and Atmospheric Administration, the Atlantic White Shark Conservancy, and scuba diving sites worldwide. Based on these identified customers and their needs, a target power output of 50 watts was determined. Beyond this power requirement, the generator is required to resist corrosion, withstand rough marine conditions, and be modular as well as requiring low maintenance. …

The Dynamic Response And Damage Evolution Of High-Strength Concrete, Mohamed Abbas

Mechanical Engineering Research Theses and Dissertations

Concrete stands as the most extensively used construction material in both military and civil structural applications, attributed to its excellent durability and high impact resistance. Over the years, high-strength concrete (HSC) has evolved to withstand higher compressive strengths, making it a viable substitute for conventional concrete (CC) in many applications. Hence, HSC is commonly used for structures and structural elements that are exposed to extreme loading conditions such as hurricanes, wave impacts, ship-bridge collisions, explosions, earthquake loads, etc. The mechanical response of concrete subjected to dynamic loading conditions differs dramatically from its response under quasi-static conditions due to its inherent …

Design And Simulation Of Flow Channel Of Polymer Electrolyte Membrane Fuel Cell (Pemfc), Rishya Shringhan Ravichandran

Masters Theses

In Polymer Electrolyte Membrane Fuel Cell (PEMFC), flow channel plays an important role on the performance of the cell. This study mainly focuses on the simulation of flow channel under various conditions. A three-dimensional mode of PEMFC with 25cm² of active area was employed to simulate the flow channel of PEMFC which has various designs. The flow channel designs such as single serpentine, bi-serpentine and tri-serpentine channels were investigated using ANSYS FLUENT software. Initially, the flow channel width of 2mm was examined. The obtained results were compared to the experimental data to validate the model. Then, the dimension of …

Experimental, Computational, And Machine Learning Methods For Prediction Of Residual Stresses In Laser Additive Manufacturing: A Critical Review, Sung Heng Wu, Usman Tariq, Ranjit Joy, Todd Sparks, Aaron Flood, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In recent decades, laser additive manufacturing has seen rapid development and has been applied to various fields, including the aerospace, automotive, and biomedical industries. However, the residual stresses that form during the manufacturing process can lead to defects in the printed parts, such as distortion and cracking. Therefore, accurately predicting residual stresses is crucial for preventing part failure and ensuring product quality. This critical review covers the fundamental aspects and formation mechanisms of residual stresses. It also extensively discusses the prediction of residual stresses utilizing experimental, computational, and machine learning methods. Finally, the review addresses the challenges and future directions …

Insight Into Uniform Filming Of Lif-Rich Interphase Via Synergistic Adsorption For High-Performance Lithium Metal Anode, Yufang He, Li Wang, Aiping Wang, Bo Zhang, Hiep Pham, Jonghyun Park, Xiangming He

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Multi-scale simulation is an important basis for constructing digital batteries to improve battery design and application. Lif-rich solid electrolyte interphase (sei) is experimentally proven to be crucial for the electrochemical performance of lithium metal batteries. However, the lif-rich sei is sensitive to various electrolyte formulas and the fundamental mechanism is still unclear. Herein, the structure and formation mechanism of lif-rich sei in different electrolyte formulas have been reviewed. On this basis, it further discussed the possible filming mechanism of lif-rich sei determined by the initial adsorption of the electrolyte-derived species on the lithium metal anode (lma). It proposed that individual …

Deciphering The Controlling Factors For Phase Transitions In Zeolitic Imidazolate Frameworks, Tao Du, Shanwu Li, Sudheer Ganisetti, Mathieu Bauchy, Yuanzheng Yue, Morten M. Smedskjaer

Michigan Tech Publications

Zeolitic imidazolate frameworks (ZIFs) feature complex phase transitions, including polymorphism, melting, vitrification, and polyamorphism. Experimentally probing their structural evolution during transitions involving amorphous phases is a significant challenge, especially at the medium-range length scale. To overcome this challenge, here we first train a deep learning-based force field to identify the structural characteristics of both crystalline and non-crystalline ZIF phases. This allows us to reproduce the structural evolution trend during the melting of crystals and formation of ZIF glasses at various length scales with an accuracy comparable to that of ab initio molecular dynamics, yet at a much lower computational cost. …

Development Of On-The-Fly Quasi-Steady State Approximation For Chemical Kinetics In Cfd, Abhinav Balamurugan

Doctoral Dissertations and Master's Theses

This study analyzes the feasibility of On-The-Fly Quasi-Steady-State Approximation (OTF-QSSA) application for solving chemical kinetics within Computational Fluid Dynamics (CFD) simulations, aiming to reduce the computational demand of detailed mechanisms. An algorithm that dynamically identifies and designates Quasi-Steady-State (QSS) species at specific grid locations and instances during the simulation was developed. With this information, our method pseudo-delays the advancement of concentrations for these QSS species—effectively setting their rate of concentration change to zero for a set number iteration before updating using the detailed mechanism and thereby omitting the computationally intensive processes typically required for their calculation during those skipped iteration. …

Benchmarking Of A Sco2 Heat Exchanger Flow Loop, David Velasco

Doctoral Dissertations and Master's Theses

Heat transfer of supercritical carbon dioxide (sCO2) was studied experimentally by commissioning a sCO2 flow loop featuring a horizontal tube-in-tube counterflow heat exchanger with a circular cross section. The main objective was to establish experimental heat transfer research capabilities for sCO2 at Embry-Riddle Aeronautical University’s (ERAU) Thermal Science Lab. sCO2 experiences a drastic change in thermophysical properties near its critical point that results in unique heat transfer characteristics. The high pressures at which sCO2 exists make the large gradients in thermophysical and transport properties difficult to study, experimentally and numerically. However, understanding the heat transfer characteristics and thermophysical behavior of …

Inertial Particle Clustering Due To Turbulence In An Air Jet, Bianca Viggiano, Kris Gish, Stephen Solovitz, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Explosive volcanic eruptions create turbulent plumes of fine ash particles. When these particles collide in the presence of moisture and electrostatic fields they combine into larger aggregates, which can significantly change the atmospheric residence time of the airborne cloud. Previous studies have suggested that turbulence may lead to preferential concentration—also known as clustering—of particles within the flow, increasing the likelihood of collisions and aggregation. Few experimental studies have quantified these processes for volcanic plumes. This behavior was investigated using a particle-laden air jet. By systematically varying the exit speed and the size, density, and concentration of particles, flows were produced …

Material Modeling Of An Ultraviolet Sensitive Resin At High Pressures And Rates, Truman Miller Russell

Master's Theses (2009 -)

A full understanding of the behavior of binder materials under shock loading is required for effective simulation of heterogeneous polymer-binder-explosives (PBX) and polymer-binder-surrogate (PBS) systems. An accurate simulation is critical for the ultimate goal of designing meso-scale heterogeneous PBS systems. The binder materials studied here is an ultraviolet sensitive resin (UV resin). The UV resin is manufactured by AnyCubic. It is a glassy thermoset polymer and is known to be similar to polymethyl methacrylate (PMMA) both in mechanical properties and in chemical makeup. This material was chosen as it can be additively manufactured, and it will present a lower impedance …

A Study Of The Effect Of Preparation Parameters On The Mechanical Properties Of Freeze-Dried Gelatin-Elastin-Hyaluronate Scaffolds, Mansour Qamash

Master's Theses (2009 -)

This thesis is dedicated to a detailed study of changes in the properties of Gelatin-Elastin-Hyaluronate (GEH) tissue engineering scaffold resulting from changes in preparation parameters. More specifically, utilizing a combination of foaming and freeze-drying techniques, this research investigates the effects of different parameters, including agitation speed, duration time, and chilling temperature on the scaffold’s structural integrity, porosity, and mechanical properties. The methodology involves a carefully calibrated process in which the scaffold matrix is initially prepared by incorporating 8% gelatin, 2% elastin, and 0.5% hyaluronate (w/v) into a homogenous aqueous solution, followed by controlled agitation and subsequent freezing at designated temperatures. …

Investigating The Impacts Of Bin Variability On Particle Size Distributions In Multiphase Eulerian-Eulerian Simulations, Wilbert Alexander Cruz

Master's Theses (2009 -)

In this study, a 3D steady-state Eulerian-Eulerian simulation was developed to investigate flow performance in a dilute pneumatic conveying system. The investigation focused on two main objectives: (1) assessing the influence of bin selection on solution accuracy for representing the polydisperse mixture, and (2) exploring methods to simplify the modeling of polydisperse particles in the simulation by utilizing a mean diameter derived from the mixture’s particle size distribution. The system's geometry and initial boundary conditions featured a 10.6 m long, 150 mm diameter horizontal pipe with both gaseous and solid phases initially moving at 27 m/s . The steady-state simulation …

Segregation And Heat Treatment Response Of Cast Quench And Partition Steels, Mujeeb Hussain Shaik

Masters Theses

Quench and partition (Q&P) steels have emerged as promising alternatives to traditional quenching and tempering methods, offering a superior balance of strength and ductility due to their unique microstructure of martensite, and retained austenite. This literature review examines the development and optimization of Q&P steels, focusing on their mechanical properties, heat treatment processes, and applications in various industries. This study explores the application and effectiveness of the Quench and Partition (Q&P) heat treatment process on cast steels and examines segregation phenomena in cast medium Mn steels. Medium Mn steels were employed for various Q&P cycles on cast specimens to investigate …

Surgical Navigation In Image-Guided Transoral Robotic Surgery, Yuan Shi

Dartmouth College Ph.D Dissertations

Transoral robotic surgery (TORS) is a minimally invasive approach in treating head and neck cancers and has demonstrated improved surgical outcomes with reduced morbidity when compared to traditional open surgery. However, the lack of haptic feedback makes it more difficult to assess the tumor extent and locate critical structures (e.g., artery and nerves). In standard-of-care TORS, preoperative imaging is used as guidance; however, it becomes inaccurate intraoperatively: the patient’s neck is hyper-extended, surgical instruments are introduced, and soft tissues deform significantly. As a result, the surgeon is required to mentally predict intraoperative deformation, which can lead to bleeding complications and …

Obliquely Impinging Jet Heat Transfer Fields: Effects Of Mach Number On Nozzle-To-Plate Distance, Thinnesh Ragupathy

Masters Theses

This study investigates the consistent features of heat flux patterns on surfaces impacted by jets at various Mach numbers, ranging from 0.1 to 1.0. It utilizes temperature-sensitive paint (TSP) analysis to examine how these patterns change. The research also explores the presence of self-similarity in both the fluctuation of heat flux and skin friction patterns, which are derived from temperature and heat flux data. A semi-empirical model is proposed to explain this self-similarity, suggesting that Mach number primarily affects heat flux patterns through the recovery temperature at the impact site.

Understanding the self-similarity of heat flux patterns across different Mach …

Redesign Of Robotic Walking Training Device To Involve Zero Gravity Capabilities And Daily Activities, Chad Ballard

Mechanical Engineering Theses

Many patients struggle with disabilities that hinder their ability to walk. This project aimed to create a leg assembly capable of variable gravity so that it could be combined with a Robotic Walking Training Device, and lead to better rehabilitation options for patients. This was accomplished by deriving equations of joint torque, creating circuit diagrams for Arduino systems, modeling leg assemblies in CAD, and finally combining it to create a working small-scale prototype. The result of the prototype testing showed accurate movement on each joint, especially the ankle and knee segments, to create virtual zero gravity. In addition to this, …

Removable Equipment Climate Canopy, Jessica Perez, Sabine Heid, Zil Panchal, Anali Salazar

Mechanical Engineering

The Climate Canopy Project has developed an improved solution for creating an adjustable shade mechanism tailored specifically for users of pull walkers. Through extensive research, goal setting, and a comprehensive framework our project has examined the challenges faced by individuals who rely on walkers for mobility. Our stakeholder requires a product that is lightweight, removable, and compact. This study dissected the designs of previous products on the market and aimed to build a product that aligns with our sponsor’s desires.

This report presents the main goals for the design and manufacturing process, along with key design features utilized to produce …

Nonparametric Identification Of A Mems Resonator Actuated By Levitation Forces, Mohammed Abdel Razzaq, Rodrigo T. Rocha, Yu Tian, Shahrzad Towfighian, Sami F. Masri, Mohammad I. Younis

Mechanical Engineering Faculty Scholarship

This work presents nonparametric identification of a Micro-Electro-Mechanical Systems (MEMS) beam subjected to a non-classical nonlinear electrostatic (levitation) force. The approach is based on the Restoring Force Surface method and the Chebyshev polynomials. The study examines the main challenges associated with the used approach as applied to small-scale systems, such as the inability to measure the restoring force and acceleration. In this work, we use a mix of analytical techniques, experimental data, and Lagrange polynomial interpolation to estimate the restoring forces of the system and its nonlinearities. The extracted results are compared with the measurements, which show excellent agreement. Results …

Synthesis And Structure-Property Relationships Of Sustainable Nanostructured Materials Towards Energy And Environment Applications, Nizamudeen Cherupurakal

Dissertations

This doctoral research aims to advance clean energy technologies by developing specialized nanostructured materials. The study covers significant research themes, each forming separate sections in the thesis, explaining the important role of nanostructures in enhancing the efficiency and sustainability of energy devices and photocatalytic technologies.

The enduring effort toward stabilizing and improving the efficiency of Dye-Sensitized Solar Cells (DSSCs) has stirred the solar research community to follow innovative approaches. The primary objective of the research is centered on electrode materials design, which improves photoanodes' Light-Harvesting Efficiency (LHE). To improve the Photoanode of DSSCs, a Metal-Organic Framework (MOF) derived porous photoanodes …

Convolutional Spiking Neural Networks For Intent Detection Based On Anticipatory Brain Potentials Using Electroencephalogram, Nathan Lutes, V. Sriram Siddhardh Nadendla, K. Krishnamurthy

Computer Science Faculty Research & Creative Works

Spiking neural networks (SNNs) are receiving increased attention because they mimic synaptic connections in biological systems and produce spike trains, which can be approximated by binary values for computational efficiency. Recently, the addition of convolutional layers to combine the feature extraction power of convolutional networks with the computational efficiency of SNNs has been introduced. This paper studies the feasibility of using a convolutional spiking neural network (CSNN) to detect anticipatory slow cortical potentials (SCPs) related to braking intention in human participants using an electroencephalogram (EEG). Data was collected during an experiment wherein participants operated a remote-controlled vehicle on a testbed …

Cosolvent Incorporation Modulates The Thermal And Structural Response Of Pnipam/Silyl Methacrylate Copolymers, Jason D. Linn, Fabian A. Rodriguez, Michelle A. Calabrese

Mechanical Engineering Faculty Publications

Polymers functionalized with inorganic silane groups have been used in wide-ranging applications due to the silane reactivity, which enables formation of covalently-crosslinked polymeric structures. Utilizing stimuli-responsive polymers in these hybrid systems can lead to smart and tunable behavior for sensing, drug delivery, and optical coatings. Previously, the thermoresponsive polymer poly(N-isopropyl acrylamide) (PNIPAM) functionalized with 3-(trimethoxysilyl)propyl methacrylate (TMA) has demonstrated unique aqueous self-assembly and optical responses following temperature elevation. Here, we investigate how cosolvent addition, particularly ethanol and N,N-dimethyl formamide (DMF), impacts these transition temperatures, optical clouding, and structure formation in NIPAM/TMA copolymers. Versus purely aqueous …

Lamina Cribrosa Insertions Into The Sclera Are Sparser, Narrower, And More Slanted In The Anterior Lamina, Fengting Ji, Mohammad R. Islam, Bingrui Wang, Yi Hua, Ian A. Sigal

Mechanical Engineering Faculty Publications

Purpose: The lamina cribrosa (LC) depends on the sclera for support. The support must be provided through the LC insertions. Although a continuous insertion over the whole LC periphery is often assumed, LC insertions are actually discrete locations where LC collagenous beams meet the sclera. We hypothesized that LC insertions vary in number, size, and shape by quadrant and depth.

Methods: Coronal cryosections through the full LCs from six healthy monkey eyes were imaged using instant polarized light microscopy. The images were registered into a stack, on which we manually marked LC insertion outlines, nothing their position in-depth and quadrant …