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2024

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Articles 781 - 810 of 1308

Full-Text Articles in Mechanical Engineering

Use Of Mathematical Skills For Technical Condition Assessment Of Power Autotransformers, Dilafruz Rustamjon Qizi Abdullabekova, Nurali Berdiyorovich Pirmatov Apr 2024

Use Of Mathematical Skills For Technical Condition Assessment Of Power Autotransformers, Dilafruz Rustamjon Qizi Abdullabekova, Nurali Berdiyorovich Pirmatov

Technical science and innovation

In this paper, we review innovative approaches to assess the technical condition of autotransformers using mathematical methods. The main purpose of these methods is to increase the efficiency of diagnostics and prevent possible failures in power systems. The developed mathematical expression is based on complex data analysis, application of statistical methods and machine learning technologies. This makes it possible to achieve more accurate and earlier detection of potential problems. As a result of these innovative approaches, the possibilities for early detection and prevention of faults are significantly increased. This is important for ensuring the smooth operation of power systems and …


Quantitative Assessment And Characterization Of Tool Wear Phenomena In Advanced Manufacturing Processes, Oybek Valijonovich Tuyboyov Apr 2024

Quantitative Assessment And Characterization Of Tool Wear Phenomena In Advanced Manufacturing Processes, Oybek Valijonovich Tuyboyov

Technical science and innovation

This paper explores the quantitative assessment and characterization of tool wear phenomena in advanced manufacturing processes, employing a multifaceted approach encompassing traditional measurements, image processing, machine learning, and predictive modeling. The study emphasizes the intricate dynamics of tool wear and its direct impact on cutting tool performance, addressing challenges in real-time monitoring and optimization of machining operations. Traditional methods like VBmax measurement are juxtaposed with advanced techniques such as the improved conditional generative adversarial net with a high-quality optimization algorithm (CGAN-HQOA), efficient channel attention destruction and construction learning (ECADCL), and shape descriptors based on contour, moments, orientations, and texture. Artificial …


Experimental Studies On Determination Of Loading And Laws Of Motion Of The Accelerator Of The Raw Material Chamber Of The Saw Gin, Yusuf Abbasovich Axmedjanov Apr 2024

Experimental Studies On Determination Of Loading And Laws Of Motion Of The Accelerator Of The Raw Material Chamber Of The Saw Gin, Yusuf Abbasovich Axmedjanov

Technical science and innovation

The findings of research conducted on the saw gin’s accelerator in its raw chamber are displayed at different belt drive eccentricity values, both in the absence of load and with technological load. It has been discovered that, in a steady-state scenario without a load, the maximum torque value increases as the eccentricity of the system’s tension roller increases in a technological load scenario, the torque minimum is noted at an eccentricity of e = 3 mm. When conducting experiments under load, the average angular velocity fluctuation amplitude and the coefficient of unevenness of rotation have minimum values at zero eccentricity …


Implementing A Solar Photovoltaic Station In Watering Systems Utilizing Complex Software, Akbarxon Sarvar O'G'Li Uroqov, Faxriddin Jaylovovich Nosirov, G'Olibjon Pardayevich Arzikulov, Zarina Amriddin Qizi Sayfutdinova Apr 2024

Implementing A Solar Photovoltaic Station In Watering Systems Utilizing Complex Software, Akbarxon Sarvar O'G'Li Uroqov, Faxriddin Jaylovovich Nosirov, G'Olibjon Pardayevich Arzikulov, Zarina Amriddin Qizi Sayfutdinova

Technical science and innovation

This article explores the benefits of transitioning from traditional agricultural irrigation systems to more cost-effective alternatives powered by renewable energy sources. By integrating solar photovoltaic technology into irrigation processes, significant reductions in resource wastage, estimated at 45-50%, are achievable through the implementation of drip irrigation techniques. This results in enhanced agricultural productivity. Moreover, the utilization of solar panels in green zones mitigates surface temperature increases, contributing to a 2-5% boost in electricity production. Currently, irrigation facilities primarily rely on the main energy grid. However, transitioning to renewable energy sources decreases reliance on non-renewable fuels, reduces greenhouse gas emissions, and fosters …


Globular Protein For Surface Modification Of Cellulosecontaining Materials, Nodira Saydaliyeva Apr 2024

Globular Protein For Surface Modification Of Cellulosecontaining Materials, Nodira Saydaliyeva

Technical science and innovation

The purpose of this work is the chemical modification of cotton fabrics with natural globular protein. Modification was carried out in the process of finishing cotton fabrics, after decoction and bleaching in a continuous mode. The effect of modification on the strength, protein content and functional groups of cotton fabric has been studied. According to the results obtained using the AUTOGRAPH AGS-N machine, it was found that the modification of cotton fabrics with a solution of globular protein increases the strength of the treated fabrics, depending on the concentration of the modifier and the temperature regime. Treatment with a highly …


Dying Of Natural Silk Deglued By Various Methods, Venera Djavdatovna Khamidova Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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. …


Deciphering The Controlling Factors For Phase Transitions In Zeolitic Imidazolate Frameworks, Tao Du, Shanwu Li, Sudheer Ganisetti, Mathieu Bauchy, Yuanzheng Yue, Morten M. Smedskjaer Apr 2024

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. …


The Dynamic Response And Damage Evolution Of High-Strength Concrete, Mohamed Abbas Apr 2024

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 …


Application Of The Fokker-Planck Equation For Quantifying Initial Condition Uncertainty Of Reversible Dynamic Systems, Troy S. Newhart Apr 2024

Application Of The Fokker-Planck Equation For Quantifying Initial Condition Uncertainty Of Reversible Dynamic Systems, Troy S. Newhart

Mechanical & Aerospace Engineering Theses & Dissertations

Characterizing the behavior of dynamic systems requires the inclusion of initial conditions to propagate behavior forward in time. More realistic representations of system behavior quantify uncertainty about the initial conditions to assess sensitivity, reliability, and other stochastic response parameters. In many engineering applications, the uncertain initial conditions may be unknown given a desired response. This research applies the Fokker-Planck equation to reversible dynamic systems of select multi-dimensional nonlinear differential equations as a means for predicting the uncertainty about initial conditions. An alternating directions implicit numerical scheme is used to numerically solve the Fokker-Planck equation for both forward and reversed equations …


Thermo-Elasto-Plastic Stability Of Biaxially Loaded Hollow Rectangular Section Steel Beam-Columns With Applied Torsion, George Adomako Kumi Apr 2024

Thermo-Elasto-Plastic Stability Of Biaxially Loaded Hollow Rectangular Section Steel Beam-Columns With Applied Torsion, George Adomako Kumi

Civil & Environmental Engineering Theses & Dissertations

Presented herein is an experimental and theoretical study of biaxially loaded hollow rectangular section steel beam-columns with applied torsion at elevated temperatures. The theoretical analysis is based on a system of simultaneous materially nonlinear differential equations of equilibrium for which an iterative semi-analytic solution approach is formulated. Although the primary goal of this research is to study the influence of elevated temperatures on the steel member with the complex loading, rigorous analysis is also conducted of the member at ambient temperature for comparison. The experimental part of the study involves conducting tests on the members at both ambient and high …


Structural Characterization Of A Tritruss Module, Lauren M. Simmons Apr 2024

Structural Characterization Of A Tritruss Module, Lauren M. Simmons

Mechanical & Aerospace Engineering Theses & Dissertations

The TriTruss is a novel structural module developed by researchers at NASA Langley Research Center (LaRC) that can be used in space to assemble large support structures for a variety of applications. One such application is the metering truss or primary mirror backbone support structure of an In-Space Assembled Telescope (iSAT). For the iSAT application, the TriTruss will be supporting mirror segments, payloads, and instruments, all of which require the TriTruss to have a high stiffness. Structural characterization from testing and analysis is needed to ensure the integrity of the struts that make up a TriTruss module is maintained when …


Design And Simulation Of Flow Channel Of Polymer Electrolyte Membrane Fuel Cell (Pemfc), Rishya Shringhan Ravichandran Apr 2024

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 Apr 2024

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 Apr 2024

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 …


Development Of On-The-Fly Quasi-Steady State Approximation For Chemical Kinetics In Cfd, Abhinav Balamurugan Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 …