Mechanical Engineering Commons^™

Passive Mechanical Properties Of Cardiac And Arterial Tissue: A Paired Comparison Study In A Calf Model, Ola Alsaadi, Jieyang Zhang, Masod Sadipour, Ali N. Azadani

DU Undergraduate Research Journal Archive

Purpose: The mechanical behavior of heart tissue plays a crucial role in elucidating cardiac physiology and pathophysiology. Accurate measurement of the mechanical properties of cardiac and arterial tissues is indispensable for advancing computer simulations and developing medical devices. This study aimed to assess the passive mechanical properties of cardiac and arterial tissue in a calf model using a paired comparison method.

Methods: A planar biaxial stretching device was used to determine the mechanical characteristics of 84 square specimens obtained from 14 different anatomical regions. Cauchy stress-Green strain curves were constructed for each anatomical area, and a Fung-type constitutive …

Impact Of Student Beliefs And Self-Efficacy On Performance In Higher Education Stem Courses, Lauren Nicole Fogg

Doctoral Dissertations

In engineering education, students often face feelings of inadequacy, leading to academic struggles and potential dropout. This dissertation investigates the impact of interactive course materials on students' confidence and self-efficacy in problem-solving, focusing on an Engineering Materials class at Louisiana Tech University. Over four quarters, involving seven sections and 218 students, a 13-question Likert scale survey was administered repeatedly, alongside demographic data and textbook usage surveys. The study aims to compare students’ attitudes and beliefs when not using a textbook versus when using an interactive web-native book. Hypotheses suggest that the interactive book will enhance problem-solving beliefs, confidence, and grades. …

Redesign Of Leg Assembly For Remote Walking Training Device To Improve Gait Kinematics, Jacob Anthony

Mechanical Engineering Theses

As modern medicine has improved, the average age of patients has increased. This has cause a growing number of patients to develop disabilities over time due to spinal cord injuries and stroke among other neurological ailments. This has led to an increased interest in developing robotic exoskeletons to help patients with neuromuscular rehabilitation. However, most exoskeletons do not accurately replicate the natural human gait kinematics due to a lack of degrees of freedom at the designed knee joint. In this thesis, the leg assembly for a robotic rehabilitation (RoboREHAB) device is redesigned to improve the gait kinematics and a reinforcement …

Regular Algorythms For Synthesis Of Optimal Control Systems For Dynamic Objects, Igamberdiyev Husan, Uktam Farkhodovich Mamirov, Xankeldiyeva Zebiniso

Technical science and innovation

The article presents algorithms for the synthesis of an optimal control system for dynamic objects. As a model, we consider a differential equation of a continuous one-dimensional system in the form of a state space, which has the properties of controllability and observability. The paper shows the need to use an observation device in order to assess how the properties of the controlled system change with the slightest change in the parameters of the control object, to assess the sensitivity of the system to these changes. When finding a solution to the equation formulated to find the parameters of the …

Creating A Collapsible Sling Lift Capable Of Transporting Patients Between Various Locations, Cameron Delaney Hillman, Macey Jewell Ross, Lydia Noel Miller

Honors Theses

As Senior Biomedical Engineering students at the University of Mississippi, we, Lainey Hillman, Lydia Miller, and Macey Ross, are required to complete a final senior capstone for our department. This project aims to provide a solution to a current unmet clinical need in the healthcare industry, thus our team sought to improve the lack of transportability of sling lifts. The current sling lifts on the market display numerous issues: heavy, bulky, use confined to certain areas, and use specific for only one type of transportation. To combat these problems, we designed a sling lift that was lightweight, collapsible, safe, and …

Creating A Collapsible Sling Lift Capable Of Transporting Patients Between Various Locations, Macey Jewell Ross, Cameron Delaney Hillman, Lydia Noel Miller

Honors Theses

As Senior Biomedical Engineering students at the University of Mississippi, we, Lainey Hillman, Lydia Miller, and Macey Ross, are required to complete a final senior capstone for our department. This project aims to provide a solution to a current unmet clinical need in the healthcare industry, thus our team sought to improve the lack of transportability of sling lifts. The current sling lifts on the market display numerous issues: heavy, bulky, use confined to certain areas, and use specific for only one type of transportation. To combat these problems, we designed a sling lift that was lightweight, collapsible, safe, and …

Studying The Production Of Nanocelluloses, Shohzodbek Abduvahobovich Rashidov, Elmurod Abduqodirovich Egamberdiev, Sadritdin Maxamatdinovich Turabdjanov

Technical science and innovation

Nanoscience is a broad field that includes nanophysics and nanochemistry. Nanotechnologies are aimed at obtaining nanoparticles with new properties and creating materials and devices based on them. This is one of the modern trends in the development of science in the 21st century.

Based on the study of information about nano-sized materials, the mechanisms of their production and changes in their properties, we will consider the technology for producing nanocellulose from organic substances, i.e. from cellulose. The article describes a technology that examines devices for producing nanocellulose and the principles of their operation, as well as a combined method of …

Presence Of Atheromatous Plaques And Theirs Effects On The Blood Flow, Belhocine Mostefa Bm, Amrani Hichem Ah, Fedaoui Kamel Dr, Mazouz Hammoudi Mh

Emirates Journal for Engineering Research

The paper utilizes a finite element method to study both the blood flow and atheromatous plaques. Specifically, the COMSOL finite element package is employed to achieve a fluid model. COMSOL is a powerful finite element tool commonly used in various research and industrial domains to study multiphysics problems. The focus of the investigation is on the geometric aspects of the atheromatous plaques. The study considers different forms and arrangements of stenosis, taking into account the irregularities formed by various shapes of the plaques and the resulting flow patterns. The key findings of the research suggest that the pressure and velocity …

Analyzing Heat Generated From Electro-Osmotic Flow Utilizing Computational Fluid Dynamics, Jordan Elizabeth Grothe

Honors Thesis

Without extensive vascularization, the transfer of fluid and nutrients through human tissue is limited to diffusion and weak interstitial flow. Electroosmosis, or the flow of fluid driven by an electrical field, has become a promising solution. Scientists have begun applying electricity to human tissue to promote stronger interstitial flow; however, optimization of this process has proven to be a challenge due to ohmic heating. Cells function within a small range of temperatures and exposure to voltages exceeding the threshold will cause cells to degrade and die prematurely. This research seeks to better understand and quantify the range of voltage where …

Comparative Analysis Of Cutting Forces In Axial-Compliant And Rigid Chamfering Tools, Sultonmurod Bekpulatovich Normatov, Oybek Tuyboyov, Azimjon Axror O'G'Li Pardayev, Alisher G‘Ayratjon Ogli Boratov, Shohjahon Tuxtasin Ogli Abdullayev

Technical science and innovation

This study delves into the analysis of cutting forces in axial-compliant systems, focusing specifically on the comparison between axially spring-compensated 90° conical tools and rigid chamfering tools. The research incorporates a predictive model for chamfer size calculation in the axially spring-compensated tools, verified through experimental tests on representative parts. The study aims to control chamfer size within tolerances by adjusting process conditions and optimizing processing efficiency. By exploring the fundamentals of the chamfering process, this research offers insights into breaking sharp edges on components with positional errors and shape deformations, with a particular emphasis on aero-engine casings. The integration of …

Data-Driven And Cell-Specific Determination Of Nuclei-Associated Actin Structure, Nina Nikitina, Nurbanu Bursa, Matthew Goelzer, Madison Goldfeldt, Chase Crandall, Sean Howard, Janet Rubin, Anamaria Zavala, Aykut Satici, Gunes Uzer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Quantitative volumetric assessment of filamentous actin (F-actin) fibers remains challenging due to their interconnected nature, leading researchers to utilize threshold-based or qualitative measurement methods with poor reproducibility. Herein, a novel machine learning-based methodology is introduced for accurate quantification and reconstruction of nuclei-associated F-actin. Utilizing a convolutional neural network (CNN), actin filaments and nuclei from 3D confocal microscopy images are segmented and then each fiber is reconstructed by connecting intersecting contours on cross-sectional slices. This allows measurement of the total number of actin filaments and individual actin filament length and volume in a reproducible fashion. Focusing on the role of F-actin …

Environment And Response Of 3d-Encapsulated Mesenchymal Stem Cells To Mechanical Loading, Augustus Greenwood

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis explores the micromechanical environment induced when cyclically compressing hydrogels via finite element modeling and experimentally on the impact of loading on mesenchymal stem cells (MSCs) when encapsulated withing 3D hydrogel matrices. Degenerative joint diseases, characterized by cartilage degradation, present significant challenges due to cartilage's limited self-repair capacity. Innovative approaches, including stem cell-based therapies and engineered biomaterials, have emerged as promising strategies for cartilage repair and regeneration. This work specifically investigates the calibration of a bioreactor, the uniformity of load response across the hydrogel constructs via finite element modeling (FEM), and the stress response of MSCs subjected to various …

On-Demand Fabrication Of Piezoelectric Sensors For In-Space Structural Health Monitoring, Amanda White, Isaac Little, Anastasiya Artyuk, Nicholas Mckibben, Fereshteh Rajabi Kouchi, Claire Chen, David Estrada, Zhangxian Deng

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Inflatable structures, promising for future deep space exploration missions, are vulnerable to damage from micrometeoroid and orbital debris impacts. Polyvinylidene fluoride-trifluoroethylene (PVDF-trFE) is a flexible, biocompatible, and chemical-resistant material capable of detecting impact forces due to its piezoelectric properties. This study used a state-of-the-art material extrusion system that has been validated for in-space manufacturing, to facilitate fast-prototyping of consistent and uniform PVDF-trFE films. By systematically investigating ink synthesis, printer settings, and post-processing conditions, this research established a comprehensive understanding of the process-structure-property relationship of printed PVDF-trFE. Consequently, this study consistently achieved the printing of PVDF-trFE films with a thickness of …

Characterizing The Molecular And Cellular Changes Of Senescent Cells Induced By Diverse Stressors In 2d And 3d Microenvironments, Apoorva Chauhan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aging is a risk factor for myriad diseases and is often associated with the accumulation of senescent cells. Cellular senescence, a process of irreversible cell cycle arrest, is associated with various changes in cellular morphology and function. While senescence will occur naturally in a time-dependent manner, it can be prematurely induced by various extrinsic and intrinsic factors. Most senescence studies model cell behavior in two-dimensional (2D) microenvironments; however, these models are not physiologically relevant. In this study, the effects of naturally occurring reactive oxygen species (ROS) hydrogen peroxide (H2O2) and commonly used chemotherapy drugs, doxorubicin and palbociclib, on cellular senescence …

Reducing Glass Loss During Transportation And Storage, Abdulaziz Muzafarovich Qurbanov, Mirzaabdullayev Jaxongir Baxtiyorovich

Technical science and innovation

The article discusses the processes of transportation and storage of sheet glass in the production of protective glass for cars. The experience of organizing the transportation and storage of glass in developed countries of the world was analyzed in order to study the problems of losses of raw materials during the transportation and storage of laminated glass, as well as to develop and approve a regulatory and technical document. in this field. The supplies of various brands of polished laminated glass used in the production of protective glass for cars to Avtooina LLC from different addresses, from different manufacturers were …

Ferroresonance In Three-Phase Electrical Networks, Shavkat Ernstovich Begmatov

Technical science and innovation

Possible modes of ferroresonance in three-phase electric networks and analysis of substitution schemes where ferroresonance voltage increase is observed are considered. The most complete magnetization curve of the transformer core and the analysis of the generalized equivalent substitution scheme are presented, as a result of which more accurate formulas for determining the values of equivalent parameters of the electrical network and voltage transformer in ferroresonance mode are obtained. Factor of ferroresonance voltage increase is introduced, which determines ratio between amplitude values of transformer phase voltage and mains voltage. The method of determination of boundary conditions of steady ferroresonance voltage increase …

Main Prospects Of Natural Gas Purification Technologies From Acidic Compounds, Oybek Yusupdjanovich Aripdjanov, Diyora Zokhid Qizi Khayrullaeva, Jonibek Avazek Ogli Abdumuminov

Technical science and innovation

The article discusses the main prospects for the technology of purifying natural gas from acidic components and the problems of ensuring the purity of oil and gas products in accordance with state standards. An increase in the degree of purification from H₂S, CO₂, elemental sulfur, carbonyl sulfide, ethyl mercaptans (thiols), methyl mercaptan, carbon disulfide, sulfides, disulfides (dithioethers), thiophene, sulfoxides and sulfones is considered. Also, the physicochemical properties of the absorbent for the purification of sulfur compounds (generated during natural gas processing) are studied. Based on the study of various absorbents (ethanolamine (EA), methylethanolamine (MEA), diethanolamine (DEA), …

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

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 …

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 …

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 …

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 …

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, …

Finite Element Analysis Of The Bearing Component Of Total Ankle Replacement Implants During The Stance Phase Of Gait, Timothy S. Jain

Master's Theses

Total ankle replacement (TAR) implants are an effective option to restore the range of motion of the ankle joint for arthritic patients. An effective tool for analyzing these implants’ mechanical performance and longevity in-silico is finite element analysis (FEA). ABAQUS FEA was used to statically analyze the von Mises stress and contact pressure on the articulating surface of the bearing component in two newly installed fixed-bearing total ankle replacement implants (the Wright Medical INBONE II and the Exactech Vantage). This bearing component rotates on the talar component to induce primary ankle joint motion of plantarflexion and dorsiflexion. The stress response …

Multilayer Pva/Gelatin Nanofibrous Scaffolds Incorporated With Tanacetum Polycephalum Essential Oil And Amoxicillin For Skin Tissue Engineering Application, Ebrahim Soleiman-Dehkordi, Vahid Reisi-Vanani, Samanesadat Hosseini, Zahra Lorigooini, Vajihe Azimian Zvareh, Mahour Farzan, Elham Moghtadaie Khorasgani, Karen Lozano, Zohreh Abolhassanzadeh

Mechanical Engineering Faculty Publications

Wound infection is still an important challenge in healing of different types of skin injuries. This highlights the need for new and improved antibacterial agents with novel and different mechanisms of action. In this study, by electrospinning process Tanacetum polycephalum essential oil (EO), as a natural antibacterial and anti-inflammatory agent, along with Amoxicillin (AMX) as an antibiotic are incorporated into PVA/gelatin-based nanofiber mats individually and in combination to fabricate a novel wound dressing. Briefly, we fabricated PVA/gelatin loaded by Amoxicillin as first layer for direct contact with wound surface to protects the wound from exogenous bacteria, and then built a …