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Full-Text Articles in Mechanical Engineering

Nebraska Summary #1274: New Holland T7.340 Hd, Nebraska Tractor Test Lab Jan 2023

Nebraska Summary #1274: New Holland T7.340 Hd, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Nebraska Test #2267: Case Ih Steiger 555, Nebraska Tractor Test Lab Jan 2023

Nebraska Test #2267: Case Ih Steiger 555, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Nebraska Summary #1299: Fendt 728 Vario Gen 7.1, Nebraska Tractor Test Lab Jan 2023

Nebraska Summary #1299: Fendt 728 Vario Gen 7.1, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Nebraska Summary #1295: Fendt 720 Vario Gen 7.1, Nebraska Tractor Test Lab Jan 2023

Nebraska Summary #1295: Fendt 720 Vario Gen 7.1, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Aerosol Synthesis Of Tungsten Bronze Particles For Nir Shielding, Hao Tu Jan 2023

Aerosol Synthesis Of Tungsten Bronze Particles For Nir Shielding, Hao Tu

Theses and Dissertations

This dissertation emphasizes the need for efficient energy use in buildings and transportation due to global warming and the energy crisis. It suggests that improving energy efficiency can help reduce energy consumption and emissions and support sustainability. The dissertation introduces various transparent materials that can block near-infrared (NIR) radiation from solar radiation to save energy and money, and it highlights the growing market value of such products. The dissertation compares tungsten bronze with other NIR shielding materials and shows its advantages. The dissertation introduces a cheap and environmentally friendly method for continuously producing tungsten bronze particles via aerosol synthesis. Particle …

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Distillery, Clare Nicholas, Patrick Hanlon Jan 2023

Distillery, Clare Nicholas, Patrick Hanlon

Williams Honors College, Honors Research Projects

The goal for this project is to make a cost effective still. We will be implementing cost saving parts to create a cheap but effective still. From initial research conducted, we will try to combine a stainless steel still and copper still together so that the cheaper material (stainless steel) and the component that removes sulfur compounds (copper) are both implemented. The ME side of the project will focus on the actual design and construction of the parts that will be implemented into the still. Included in the design process will be calculations of heat transfer for the current and …

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An Experimentally Validated Computational Model For The Degradation And Fracture Of Magnesium-Based Implants In A Chemically Corrosive Environment, Mark M. Ousdigian Jan 2023

An Experimentally Validated Computational Model For The Degradation And Fracture Of Magnesium-Based Implants In A Chemically Corrosive Environment, Mark M. Ousdigian

Dissertations, Master's Theses and Master's Reports

In the orthopedic and cardiovascular fields there is a growing interest for biodegradable implants, which can be naturally degraded in the body environment over time so that no extraction surgery is required. These implants must be designed to maintain their strength until the fracture has healed in the body, which could be influenced by many factors such as -the patient’s age, activities, body weight, pre-existing conditions etc. Hence, an ideal implant design should be done on a patient-by-patient basis. In the present work, a computational model is developed to predict the degradation and fracture of magnesium-based implants in a stress-coupled …

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Additively Manufactured Carbon Fiber- Reinforced Thermoplastic Composite Mold Plates For Injection Molding Process, C. Bivens, A. Wood, D. Ruble, M. Rangapuram, S. K. Dasari, K. Chandrashekhara, J. Degrange Jan 2023

Additively Manufactured Carbon Fiber- Reinforced Thermoplastic Composite Mold Plates For Injection Molding Process, C. Bivens, A. Wood, D. Ruble, M. Rangapuram, S. K. Dasari, K. Chandrashekhara, J. Degrange

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Polymer injection molding processes have been used to create high-volume parts quickly and efficiently. Injection molding uses mold plates that are traditionally made of very hard tool steels, such as P20 steel, which is extremely heavy and has very long lead times to build new molds. In this study, composite-based additive manufacturing (CBAM) was used to create mold plates using long-fiber carbon fiber and polyether ether ketone (PEEK). These mold plates were installed in an injection molding machine, and rectangular flat plates were produced using Lustran 348 acrylonitrile butadiene styrene (ABS). Tensile and flexural testing was performed on these parts …

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Fine-Grained Activity Classification In Assembly Based On Multi-Visual Modalities, Haodong Chen, Niloofar Zendehdel, Ming-Chuan Leu, Zhaozheng Yin Jan 2023

Fine-Grained Activity Classification In Assembly Based On Multi-Visual Modalities, Haodong Chen, Niloofar Zendehdel, Ming-Chuan Leu, Zhaozheng Yin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Assembly activity recognition and prediction help to improve productivity, quality control, and safety measures in smart factories. This study aims to sense, recognize, and predict a worker's continuous fine-grained assembly activities in a manufacturing platform. We propose a two-stage network for workers' fine-grained activity classification by leveraging scene-level and temporal-level activity features. The first stage is a feature awareness block that extracts scene-level features from multi-visual modalities, including red, green blue (RGB) and hand skeleton frames. We use the transfer learning method in the first stage and compare three different pre-trained feature extraction models. Then, we transmit the feature information …

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Comparison Of The Thermal Stability In Equal-Channel-Angular-Pressed And High-Pressure-Torsion-Processed Fe–21cr–5al Alloy, Maalavan Arivu, Andrew Hoffman, Jiaqi Duan, Jonathan Poplawsky, Xinchang Zhang, Frank W. Liou, Rinat Islamgaliev, Ruslan Valiev, Haiming Wen Jan 2023

Comparison Of The Thermal Stability In Equal-Channel-Angular-Pressed And High-Pressure-Torsion-Processed Fe–21cr–5al Alloy, Maalavan Arivu, Andrew Hoffman, Jiaqi Duan, Jonathan Poplawsky, Xinchang Zhang, Frank W. Liou, Rinat Islamgaliev, Ruslan Valiev, Haiming Wen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Nanostructured Steels Are Expected to Have Enhanced Irradiation Tolerance and Improved Strength. However, They Suffer from Poor Microstructural Stability at Elevated Temperatures. in This Study, Fe–21Cr–5Al–0.026C (Wt%) Kanthal D (KD) Alloy Belonging to a Class of (FeCrAl) Alloys Considered for Accident-Tolerant Fuel Cladding in Light-Water Reactors is Nanostructured using Two Severe Plastic Deformation Techniques of Equal-Channel Angular Pressing (ECAP) and High-Pressure Torsion (HPT), and their Thermal Stability between 500–700 °C is Studied and Compared. ECAP KD is Found to Be Thermally Stable Up to 500 °C, Whereas HPT KD is Unstable at 500 °C. Microstructural Characterization Reveals that ECAP KD …

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Static I-V Based Pim Evaluation For Spring And Fabric-Over-Foam Contacts, Kalkidan W. Anjajo, Yang Xu, Shengxuan Xia, Yuchu He, Haicheng Zhou, Hanfeng Wang, Jonghyun Park, Chulsoon Hwang Jan 2023

Static I-V Based Pim Evaluation For Spring And Fabric-Over-Foam Contacts, Kalkidan W. Anjajo, Yang Xu, Shengxuan Xia, Yuchu He, Haicheng Zhou, Hanfeng Wang, Jonghyun Park, Chulsoon Hwang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Spring Clips and Fabric-Over-Foams (FOFs) Are Widely Used in Mobile Devices for Electrical Connection Purposes. However, the Imperfect Metallic Connections Tend to Induce Passive Intermodulation (PIM), Resulting in a Receiver Sensitivity Degradation, Known as RP Desensitization. Due to the Complexity of the PIM Characterization, there is Not Yet a Way to Evaluate PIM Performance using a Simple Setup for Environments Like Factories. in This Paper, a Current-Voltage (I-V) Behavior-Based PIM Evaluation Method is Proposed and Validated with Various Metallic Contacts and Contact Forces. the Test Results Demonstrated the Feasibility of the PIM Performance Evaluation based on the Measured Static I-V …

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Application Of A Variable Path Length Repetitive Process Control For Direct Energy Deposition Of Thin-Walled Structures, Elias B. Snider, Douglas A. Bristow Jan 2023

Application Of A Variable Path Length Repetitive Process Control For Direct Energy Deposition Of Thin-Walled Structures, Elias B. Snider, Douglas A. Bristow

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Direct Energy Deposition (DED) Additive Manufacturing is Well Suited to Fabricating Large Thin-Walled Metal Structures Such as Rocket Nozzles but Suffers from Layer-To-Layer Defect Propagation. Propagating Defects May Exhibit as Slumping or a Ripple in Bead Geometry. Recent Works Have Used Repetitive Process Control (RPC) Methods for Additive Manufacturing to Stabilize the Layer-Wise Defect Propagation, But These Methods Require Repetition of the Same Path. However, Typical Thin-Wall DED Applications, Sometimes Referred to as Vase Structures, Have Changing Paths with Each Layer Such as Expanding or Contracting Diameters and Changing Profiles. This Paper Presents an Extension to Optimal RPC that Uses …

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Reinforcement Learning-Guided Quadratically Constrained Quadratic Programming For Enhanced Convergence And Optimality, Chaoying Pei, Zhi Xu, Sixiong You, Jeffrey Sun, Ran Dai Jan 2023

Reinforcement Learning-Guided Quadratically Constrained Quadratic Programming For Enhanced Convergence And Optimality, Chaoying Pei, Zhi Xu, Sixiong You, Jeffrey Sun, Ran Dai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In the context of Quadratically Constrained Quadratic Programming (QCQP) with dynamic parameters, the effectiveness of various optimization approaches is heavily influenced by the quality of the initial guess. To address this challenge, this paper proposes a novel approach that leverages reinforcement learning (RL) to generate high-performing initial guesses for iterative algorithms, with the dynamic parameters serving as inputs. Our approach aims to accelerate convergence and improve the objective value, thereby enabling efficient and effective solutions to the QCQP problem under variability. In this study, we evaluate the proposed approach by applying it to an iterative algorithm, specifically the Iterative Rank …

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Mixed-Input Learning For Multi-Point Landing Guidance With Hazard Avoidance Part Ii: Learning-Based Guidance Algorithm, Sixiong You, Chaoying Pei, Vinay Kenny, Ran Dai, Jeremy R. Rea Jan 2023

Mixed-Input Learning For Multi-Point Landing Guidance With Hazard Avoidance Part Ii: Learning-Based Guidance Algorithm, Sixiong You, Chaoying Pei, Vinay Kenny, Ran Dai, Jeremy R. Rea

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper investigates the three-dimensional (3D) multi-point landing guidance (MLG) problem with hazard avoidance by developing a mixed-input learning-based method to achieve precise and fuel-efficient planetary landing in future Mars missions. Specifically, we aim to find a safe, fuel-efficient landing point and generate a fuel-optimal trajectory simultaneously in real-time. First, by introducing binary variables, the MLG problem is formulated as an optimal control problem with quadratic constraints. Then, by formulating the Hamiltonian function, the necessary conditions of optimality for the MLG problem are obtained, where the critical parameters are identified to represent the complete optimal solution. After that, to find …

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Feature-Based Learning For Optimal Abort Guidance, Vinay Kenny, Sixiong You, Godfrey Hendrix, Chaoying Pei, Roha Gul, Ran Dai, Jeremy R. Rea Jan 2023

Feature-Based Learning For Optimal Abort Guidance, Vinay Kenny, Sixiong You, Godfrey Hendrix, Chaoying Pei, Roha Gul, Ran Dai, Jeremy R. Rea

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The abort mission refers to the mission where the landing vehicle needs to terminate the landing mission when an anomaly happens and be safely guided to the desired orbit. This paper focuses on solving the time-optimal abort guidance (TOAG) problem in real-time via the feature-based learning method. First, according to the optimal control theory, the features are identified to represent the optimal solutions of TOAG using a few parameters. After that, a sufficiently large dataset of time-optimal abort trajectories is generated offline by solving the TOAG problems with different initial conditions. Then the features are extracted for all generated cases. …

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Distributed Optimization For Rank-Constrained Semidefinite Programs, Chaoying Pei, Sixiong You, Chuangchuang Sun, Ran Dai Jan 2023

Distributed Optimization For Rank-Constrained Semidefinite Programs, Chaoying Pei, Sixiong You, Chuangchuang Sun, Ran Dai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This letter develops a distributed optimization framework for solving the rank-constrained semidefinite programs (RCSPs). Since the rank constraint is non-convex and discontinuous, solving an optimization problem with rank constraints is NP-hard and notoriously time-consuming, especially for large-scale RCSPs. In the proposed approach, by decomposing an unknown matrix into a set of submatrices with much smaller sizes, the rank constraint on the original matrix is equivalently transformed into a set of constraints on the decomposed submatrices. The distributed framework allows parallel computation of subproblems while requiring coordination among them to satisfy the coupled constraints. As the scale of every subproblem solved …

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Orbital Stabilization Of Underactuated Systems Using Time Period Regulation, Nilay Kant, Ranjan Mukherjee Jan 2023

Orbital Stabilization Of Underactuated Systems Using Time Period Regulation, Nilay Kant, Ranjan Mukherjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A new approach to orbital stabilization of under-actuated systems with one passive degree-of-freedom (DOF) is presented. Virtual holonomic constraints are enforced using partial feedback linearization; this results in a dense set of periodic orbits on a constraint manifold. Every orbit on the constraint manifold is associated with a unique time-period. A desired orbit is selected, and the impulse controlled Poincaré map (ICPM) approach is utilized to stabilize the orbit by regulating the time-period. By treating the time period as the output, it is possible to design a dead-beat controller that achieves orbital stabilization in a single time-step. The effectiveness of …

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การออกแบบแกนดามกระดูกต้นขาชนิดยาวที่เหมาะสำหรับคนไทย ด้วยหลักการออกแบบหารูปร่างที่เหมาะสมที่สุด, ดวงกมล สายะบุตร Jan 2023

การออกแบบแกนดามกระดูกต้นขาชนิดยาวที่เหมาะสำหรับคนไทย ด้วยหลักการออกแบบหารูปร่างที่เหมาะสมที่สุด, ดวงกมล สายะบุตร

Chulalongkorn University Theses and Dissertations (Chula ETD)

การรักษากระดูกต้นขาหักมักใช้วิธีผ่าตัดใส่แกนดามกระดูก โดยแกนดามกระดูกที่ใช้ในปัจจุบันถูกออกแบบโดยอิงจากกายวิภาคของชาวคอเคเชียน ซึ่งไม่เหมาะสมสำหรับประชากรชาวเอเชียเนื่องจากความโค้งของโพรงกระดูกไม่เหมาะสมกัน ซึ่งอาจนำไปสู่การทะลุของปลายแกนดามกระดูกได้ งานวิจัยนี้จะนำวิธีการทำ shape optimiztion มาใช้ในการออกแบบแกนดามกระดูกต้นขาชนิดยาวให้เหมาะสมกับกระดูกต้นขาคนไทย โดยจะเลือกกลุ่มตัวอย่างกระดูกต้นขา 10 กระดูกจากกลุ่มประชากรกระดูกต้นขาคนไทย 60 กระดูก โดยเลือกให้ครอบคลุมกลุ่มประชากรกระดูกต้นขาที่มีรูปร่างหลากหลาย โดยใช้วิธีการจัดกลุ่มแบบ k-means clustering แกนดามกระดูกจะถูกทำการ optimize ในกระดูกกลุ่มตัวอย่างทั้ง 10 กระดูกพร้อม ๆ กัน โดยความเค้นที่เกิดในกระดูกทุกชิ้น จะถูกใช้ในการปรับรูปร่างของแกนดามกระดูกดีไซน์ถัดไป ทำวนไปเรื่อย ๆ จนสามารถลดความเค้นในกระดูกทุกชิ้นได้ แกนดามกระดูกที่ออกแบบใหม่นี้ สามารถทำให้ความเค้นที่เกิดขึ้นในกระดูกต้นขาต่ำลงอย่างมีนัยสำคัญ เมื่อเทียบกับแกนดามกระดูกต้นขาในท้องตลาดที่มีรัศมีความโค้ง 1275, 1500, และ 2000 มิลลิเมตร โดยลดลงเฉลี่ย 96.82%, 98.31%, และ 99.15% ตามลำดับ นอกจากนี้ยังทำการทดสอบความแข็งแรงด้วยวิธีไฟไนต์เอลิเมนต์ พบว่าแกนดามกระดูกที่ออกแบบใหม่มีความแข็งแรง สามารถพัฒนาต่อยอดเพื่อไปใช้ในผู้ป่วยจริงได้ในอนาคต

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Post-Weld Heat Treatment Effects On Microstructure, Crystal Structure, And Mechanical Properties Of Donor Stir–Assisted Friction Stir Welding Material Of Aa6061-T6 Alloy, Aiman H. Al-Allaq, Manish Ojha, Yousuf S. Mohammed, Srinivasa N. Bhukya, Zhenhua Wu, Abdelmageed A. Elmustafa Jan 2023

Post-Weld Heat Treatment Effects On Microstructure, Crystal Structure, And Mechanical Properties Of Donor Stir–Assisted Friction Stir Welding Material Of Aa6061-T6 Alloy, Aiman H. Al-Allaq, Manish Ojha, Yousuf S. Mohammed, Srinivasa N. Bhukya, Zhenhua Wu, Abdelmageed A. Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

Friction stir welding (FSW) technology combines heat input from friction and extreme plastic deformation to produce high-quality joints in aluminum and other alloy systems. This necessitates examining the final welded joint’s mechanical and structural properties. Post-weld heat-treated AA6061-T6 alloy that resulted from the application of a Cu donor stir–assisted (CDSA) friction stir welding (FSW) material was examined for crystal structure and mechanical properties. CDSA FSW samples were tested at a constant tool rotational speed of 1400 rpm and a welding translational speed of 1 mm/s. CDSA samples of 20% and 60% thickness of the AA6061-T6 base alloy were selected to …

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A Review Of Piezoelectric Footwear Energy Harvesters: Principles, Methods, And Applications, Bingqi Zhao, Feng Qian, Alexander Hatfield, Lei Zuo, Tian-Bing Xu Jan 2023

A Review Of Piezoelectric Footwear Energy Harvesters: Principles, Methods, And Applications, Bingqi Zhao, Feng Qian, Alexander Hatfield, Lei Zuo, Tian-Bing Xu

Mechanical & Aerospace Engineering Faculty Publications

Over the last couple of decades, numerous piezoelectric footwear energy harvesters (PFEHs) have been reported in the literature. This paper reviews the principles, methods, and applications of PFEH technologies. First, the popular piezoelectric materials used and their properties for PEEHs are summarized. Then, the force interaction with the ground and dynamic energy distribution on the footprint as well as accelerations are analyzed and summarized to provide the baseline, constraints, potential, and limitations for PFEH design. Furthermore, the energy flow from human walking to the usable energy by the PFEHs and the methods to improve the energy conversion efficiency are presented. …

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Exploring Additive Manufacturing In A Space Environment - A Capstone Design Project Experience, Zain Zafar Khan, Zachary Alan Sobelman, Sharanabasaweshwara Asundi Jan 2023

Exploring Additive Manufacturing In A Space Environment - A Capstone Design Project Experience, Zain Zafar Khan, Zachary Alan Sobelman, Sharanabasaweshwara Asundi

Mechanical & Aerospace Engineering Faculty Publications

The employment of additive manufacturing in the non-standard environments like space, ships, or submarines has the potential to be an advanced utility not only in the pre-flight production of aerospace components and structures, but also for the onboard manufacturing of components and tools necessary for future space missions. For example, the ability to produce tools and structural components on the International Space Station can provide the space community the opportunity to make repairs and upgrades to the space station without wasting time and resources transporting such materials through additional missions. Additive manufacturing would allow for space missions to use on …

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Carbon Capture, Utilization, And Storage, University Of North Dakota. Energy And Environmental Research Center Jan 2023

Carbon Capture, Utilization, And Storage, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about carbon capture, utilization, and storage (CCUS) and the Energy & Environmental Research Center’s CCUS capabilities. Includes information on the Plains CO2 Reduction (PCOR) Partnership initiative, Brine Extraction and Storage Test (BEST), Carbon Storage Assurance Facility Enterprise (CarbonSAFE), Red Trail Energy Carbon Capture and Storage, a feed study at Coal Creek Station, Bell Creek and Cedar Creek anticline projects, and Partnership for CO2 Capture (PCO2C).

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Design And Validation Of A Variable, Speed-Dependent Resistance Training Method For Muscle Hypertrophy, Alvaro Andres Aracena Alvial Jan 2023

Design And Validation Of A Variable, Speed-Dependent Resistance Training Method For Muscle Hypertrophy, Alvaro Andres Aracena Alvial

Honors Undergraduate Theses

Muscle disorders and induced muscle atrophy impose critical risks to the well-being of an individual, limiting normal activities of daily living. Several resistance training methods have effectively reversed the progression of muscle atrophy. Weightlifting and hydrotherapy are the two widely practiced schemes for resistance training; however, there is the potential risk of excessive loads exerted on the muscles during weightlifting, and limited accessibility and cost are barriers to hydrotherapy. An alternative is using a resistance band. Some limitations include engaging multiple muscles/joints while only unidirectional resistance is feasible. To address these limitations, a VAriable Resistance Suit (VARS) was designed to …

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Audible And Subaudible Components Of The First And Second Heart Sounds Using Phonocardiography And Seismocardiography, Daniella King Jan 2023

Audible And Subaudible Components Of The First And Second Heart Sounds Using Phonocardiography And Seismocardiography, Daniella King

Honors Undergraduate Theses

Cardiovascular disease continues to be a leading cause of death in the United States, and a source of financial strain on the healthcare system. This prompts the need for new methods of low-cost, noninvasive technologies for cardiac monitoring to improve patient health and reduce healthcare costs. While the first and second heart sounds are common references that are listened to during auscultation of heart, seismocardiography (SCG) is a technology that detects chest sound vibrations with an accelerometer and may offer more information beyond the audible heart sounds. There is currently limited information regarding both the relationship between audible heart sounds …

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Granular Jamming: Stiffness Vs Pressure And Organ Palpation Devices, Christopher H. Quach Jan 2023

Granular Jamming: Stiffness Vs Pressure And Organ Palpation Devices, Christopher H. Quach

Honors Undergraduate Theses

The intent of this thesis it to find a correlation between the stiffness of granular jammed particles and the pressure of the vacuum initiating the jamming force. Currently, granular jamming is being used to create palpation simulators for physicians to practice feeling the variety of stiffnesses of organs when healthy or ill. Because granular jamming allows for variable stiffness of any shape, it is an apt phenomenon to simulate the change of rigidity organs like the liver undergoes when diseased. For physicians to correctly identify how stiff the organ must be when using these palpation simulators, there needs to be …

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Oxidation Layer Formation On Aluminum Substrates With Surface Defects Using Molecular Dynamics Simulation, Emmanuel Olugbade, Hiep Pham, Yuchu He, Haicheng Zhou, Chulsoon Hwang, Jonghyun Park Jan 2023

Oxidation Layer Formation On Aluminum Substrates With Surface Defects Using Molecular Dynamics Simulation, Emmanuel Olugbade, Hiep Pham, Yuchu He, Haicheng Zhou, Chulsoon Hwang, Jonghyun Park

Electrical and Computer Engineering Faculty Research & Creative Works

Aluminum Oxide Layer Affects the Integrity of Electrical Contact and Can Contribute Adversely to Passive Intermodulation (PIM) Behavior in Radio Frequency (RF) Devices, necessitating a Need for Understanding its Formation Mechanism and Realistic Estimation of its Thickness. using ReaxFF Molecular Dynamics Simulation Technique, This Study Investigated the Impact of Surface Defects on Aluminum Oxide Layer Formation. Results Reveal that Crystallographic Orientation Did Not Affect the Kinetics of Oxidation Process of Aluminum. However, the Reaction Kinetics Increased Significantly with Surface Inhomogeneities Such as Cracks, Scratches, and Grain Boundaries. a Non-Uniform Oxide Layer with Thickness Variation in the Range of 72-77% Was …

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Data-Driven Dynamic Motion Planning For Practical Fes-Controlled Reaching Motions In Spinal Cord Injury, Derek N.N. Wolf, Antonie J. Van Den Bogert, Eric M. Schearer Jan 2023

Data-Driven Dynamic Motion Planning For Practical Fes-Controlled Reaching Motions In Spinal Cord Injury, Derek N.N. Wolf, Antonie J. Van Den Bogert, Eric M. Schearer

Mechanical Engineering Faculty Publications

Functional electrical stimulation (FES) is a promising technology for restoring reaching motions to individuals with upper-limb paralysis caused by a spinal cord injury (SCI). However, the limited muscle capabilities of an individual with SCI have made achieving FES-driven reaching difficult. We developed a novel trajectory optimization method that used experimentally measured muscle capability data to find feasible reaching trajectories. In a simulation based on a real-life individual with SCI, we compared our method to attempting to follow naive direct-to-target paths. We tested our trajectory planner with three control structures that are commonly used in applied FES: feedback, feedforward-feedback, and model …

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Attrition Study Of Copper-Supplemented Iron-Based Oxygen Carrier For Chemical Looping Combustion, Neng Huang Jan 2023

Attrition Study Of Copper-Supplemented Iron-Based Oxygen Carrier For Chemical Looping Combustion, Neng Huang

Theses and Dissertations--Mechanical and Aerospace Engineering

Chemical looping combustion (CLC) is a promising technology that can mitigate the carbon emissions for power generation. The cost of oxygen carriers (OCs) impedes the scale up of CLC. Compared to synthetic iron-based OCs, red mud (RM), an abundant iron-based solid waste from industry, is a cost-effective choice due to its intrinsic inclusion of both inert and catalytic phases that are crucial for CLC. It was anticipated that the addition of copper oxide to RM using a mechanical mixing method that can be easily scaled up would enhance both reactivity and oxygen transport capacity (OTC), and the heat of reaction …

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Utilization Of Uncrewed Aircraft Systems Towards Investigating The Structure Of The Atmospheric Surface Layer, Loiy Al-Ghussain Jan 2023

Utilization Of Uncrewed Aircraft Systems Towards Investigating The Structure Of The Atmospheric Surface Layer, Loiy Al-Ghussain

Theses and Dissertations--Mechanical and Aerospace Engineering

This study presents two approaches to investigate the surface-layer structure during the morning transition using uncrewed aircraft systems. The first approach employs three uncrewed aircraft systems- each equipped with a single multi-hole probe- simultaneously measuring horizontal transects were partnered with a fourth measuring vertical profiles during two consecutive mornings as part of the 2017 Collaboration Leading Operational Unmanned Aerial System Development for Meteorology and Atmospheric Physics (CLOUDMAP) measurement campaign near Stillwater, Oklahoma, U.S.A. Data were analyzed to extract time-dependent single-point statistics of kinematic and thermodynamic variables from the uncrewed aircraft systems. In addition, an approach is presented by which multi-point …

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Mechanical Energy Harvester For Powering Rfid Systems Components: Modeling, Analysis, Optimization And Design, Alireza Babaei Jan 2023

Mechanical Energy Harvester For Powering Rfid Systems Components: Modeling, Analysis, Optimization And Design, Alireza Babaei

Theses and Dissertations--Mechanical and Aerospace Engineering

Finding alternative power sources has been an important topic of study worldwide. It is vital to find substitutes for finite fossil fuels. Such substitutes may be termed renewable energy sources and infinite supplies. Such limitless sources are derived from ambient energy like wind energy, solar energy, sea waves energy; on the other hand, smart cities megaprojects have been receiving enormous amounts of funding to transition our lives into smart lives. Smart cities heavily rely on smart devices and electronics, which utilize small amounts of energy to run. Using batteries as the power source for such smart devices imposes environmental and …

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