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Articles 1231 - 1260 of 1401
Full-Text Articles in Mechanical Engineering
Evaluation Of Process And Economic Feasibility Of Implementing A Topping Cycle Cogeneration System, Unique Karki
Evaluation Of Process And Economic Feasibility Of Implementing A Topping Cycle Cogeneration System, Unique Karki
Graduate Theses, Dissertations, and Problem Reports (ETD)
Industrial applications that require steam for their end-uses generally utilize steam boilers that are at higher size than what is typically required. Similarly, gas turbine-based power plants corroborate the gas turbine system and eventually relieve the exhaust into the atmosphere. These facilities include food, paper, chemicals, refining, and primary metal manufacturing industries. This research focuses on the scope of a topping cycle combined heat and power (CHP) system by pushing the load on the boiler to a higher limit, or a gas turbine operation in place of a boiler system for a topping cycle CHP and its economic feasibility by …
Techno-Economic Feasibility Of Solar Powered Electric Vehicle Charging Stations In West Virginia, Houssem Eddine Younes
Techno-Economic Feasibility Of Solar Powered Electric Vehicle Charging Stations In West Virginia, Houssem Eddine Younes
Graduate Theses, Dissertations, and Problem Reports (ETD)
This project explores the techno-economic feasibility of installing a photovoltaic (PV) system to power electric vehicle (EV) charging stations in West Virginia. A case study of a parking garage charging station is considered. The PV system performance and economic feasibility are assessed for two different system configurations and two financial scenarios. Two system variations one including PV only and another with on-site storage battery are modelled using the System Advisor Model (SAM) developed by the National Renewable Energy Laboratory. Initial technical specifications of the PV system, battery system and EV chargers were selected as a reference case. Through parametric simulation, …
Effects Of Supplementary Cementitious Materials On Early-Age Tensile Creep And Shrinkage Of Concrete, Lucas James Bucklen
Effects Of Supplementary Cementitious Materials On Early-Age Tensile Creep And Shrinkage Of Concrete, Lucas James Bucklen
Graduate Theses, Dissertations, and Problem Reports (ETD)
Determination of early-age tensile creep properties is critical for the performance of mass concrete structures at an early age. Due to the stress relaxation that tensile creep induces in concrete structures, accurate quantification of creep deformation is needed to determine the stress profile of the structure. Conventional methods of measuring tensile creep include the direct tension test where the concrete is subject to constant tensile stress. This method requires large quantities of concrete with embedded strain gauges which can only be used once. In this paper, the tensile creep parameters of concrete are found by using the restrained concrete ring …
A Study On The Hydrodynamics Of A Bench-Scale Top-Fed Bubbling Fluidized Bed Gasifier Using Biomass And Coal As Feedstocks, Ali Can Sivri
A Study On The Hydrodynamics Of A Bench-Scale Top-Fed Bubbling Fluidized Bed Gasifier Using Biomass And Coal As Feedstocks, Ali Can Sivri
Graduate Theses, Dissertations, and Problem Reports (ETD)
The production of synthetic gas (syngas) from renewable or carbon-neutral sources can significantly reduce greenhouse and other emissions associated with conventional fuels. One of the most promising technologies to efficiently convert carbonaceous feedstocks such as biomass, coal, or municipal waste into syngas for transportation, power, heat, electricity generation, and or production of added-value chemicals is the bubbling fluidized-bed gasifier (BFBG). However, the gasification process inside a BFBG is a very complex high-temperature multiphase flow phenomena still not well understood, particularly when binary mixtures are investigated. As a result, despite the numerous correlations in the literature developed to predict the hydrodynamics …
Implementation Of Radial Basis Function Artificial Neural Network Into An Adaptive Equivalent Consumption Minimization Strategy For Optimized Control Of A Hybrid Electric Vehicle, Thomas P. Harris
Graduate Theses, Dissertations, and Problem Reports (ETD)
Continued increases in the emission of greenhouse gases by passenger vehicles has accelerated the production of hybrid electric vehicles. With this increase in production, there has been a parallel demand for continuously improving strategies of hybrid electric vehicle control. The goal of an ideal control strategy is to maximize fuel economy while minimizing emissions. The design and implementation of an optimized control strategy is a complex challenge. Methods exist by which the globally optimal control strategy may be found. However, these methods are not applicable in real-world driving applications since these methods require a priori knowledge of the upcoming drive …
Design And Optimization Of Dynamic System For A One-Kw Free Piston Linear Engine Alternator-Gensets Program, Nima Zamani Meymian
Design And Optimization Of Dynamic System For A One-Kw Free Piston Linear Engine Alternator-Gensets Program, Nima Zamani Meymian
Graduate Theses, Dissertations, and Problem Reports (ETD)
In power/energy systems, free-piston linear machines are referred to as a mechanism where the constrained crank motion is eliminated and replaced with free reciprocating piston motion. Depending on the application, the piston motion can be converted into other types of energy and includes compressed air/fluid, electricity, and high temperature/pressure gas. A research group at West Virginia University developed a free-piston linear engine alternator (LEA) in 1998 and have achieved significant accomplishment in the performance enhancement of the LEAs to date. The present LEA design incorporates flexure springs as energy restoration components and as bearing supports. The advantages of using flexure …
High Tech, High Risk: Tech Ethics Lessons For The Covid-19 Pandemic Response, Emanuel Moss, Jacob Metcalf
High Tech, High Risk: Tech Ethics Lessons For The Covid-19 Pandemic Response, Emanuel Moss, Jacob Metcalf
Publications and Research
The COVID-19 pandemic has, in a matter of a few short months, drastically reshaped society around the world. Because of the growing perception of machine learning as a technology capable of addressing large problems at scale, machine learning applications have been seen as desirable interventions in mitigating the risks of the pandemic disease. However, machine learning, like many tools of technocratic governance, is deeply implicated in the social production and distribution of risk and the role of machine learning in the production of risk must be considered as engineers and other technologists develop tools for the current crisis. This paper …
Design And Development Of A Multi-Nodal Methane Detection System For Longwall Coal Mining, Amber P. Barr
Design And Development Of A Multi-Nodal Methane Detection System For Longwall Coal Mining, Amber P. Barr
Graduate Theses, Dissertations, and Problem Reports (ETD)
Methane (CH4) explosions pose significant dangers in longwall mining that may lead to injuries and fatalities. Safety is improved through diligent monitoring of CH4 concentration. Currently, regulations require a CH4 monitor be placed on the shearer, downwind of the cutting head. Portable monitor measurements must be taken at various times and locations. If any CH4 monitor measures a concentration greater than 1%, a warning signal must be given. Based on previous research and the location of the CH4 monitor mounted on the shearer (closest monitor to the face), if 1% methane is measured, the concentration at the face may be …
Additive Manufacturing Of Magnesium Alloys, Rakeshkumar Karunakaran, Sam Ortgies, Ali Tamayol, Florin Bobaru, Michael P. Sealy
Additive Manufacturing Of Magnesium Alloys, Rakeshkumar Karunakaran, Sam Ortgies, Ali Tamayol, Florin Bobaru, Michael P. Sealy
Department of Mechanical and Materials Engineering: Faculty Publications
Magnesium alloys are a promising new class of degradable biomaterials that have a similar stiffness to bone, which minimizes the harmful effects of stress shielding. Use of biodegradable magnesium implants eliminates the need for a second surgery for repair or removal. There is a growing interest to capitalize on additive manufacturing's unique design capabilities to advance the frontiers of medicine. However, magnesium alloys are difficult to 3D print due to the high chemical reactivity that poses a combustion risk. Furthermore, the low vaporization temperature of magnesium and common biocompatible alloying elements further increases the difficulty to print fully dense structures …
Evaluating The Effectiveness Of Aerospace Materials, Vehicle Shape And Astronaut Position At Lowering The Whole Body Effective Dose Equivalent In Deep Space, Daniel K. Bond
Theses and Dissertations
As future crewed, deep space missions are being planned, it is important to assess how spacecraft design can be used to minimize radiation exposure. Collectively with shielding material, vehicle shape and astronaut position must be used to protect astronauts from the two primary sources of space radiation: Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE). GCRs, which are composed of low intensity, highly energetic, and fully ionized stable and meta-stable isotopes, are considered a chronic source of radiation risk to the astronauts. SPEs, which originate from solar coronal mass ejections, are composed mostly of high intensity protons that can …
Peridynamic Approaches For Damage Prediction In Carbon Fiber And Carbon Nanotube Yarn Reinforced Polymer Composites, Forrest E. Baber
Peridynamic Approaches For Damage Prediction In Carbon Fiber And Carbon Nanotube Yarn Reinforced Polymer Composites, Forrest E. Baber
Theses and Dissertations
Aerospace structures are increasingly utilizing advanced composites because of their high specific modulus and specific strength. While the introduction of these material systems can dramatically decrease weight, they pose unique certification challenges, often requiring extensive experimental testing in each stage of the design cycle. The expensive and time-consuming nature of experimental testing necessitates the advancement of simulation methodologies to both aid in the certification process and assist in the exploration of the microstructure design space.
Peridynamic (PD) theory, originating from Sandia National Lab’s in the early 2000’s, is a nonlocal continuum-based method that reformulates the equation of motion into an …
Strategies And Devices For Improving Respiratory Drug Delivery To Infants And Children With Cystic Fibrosis, Karl Bass
Theses and Dissertations
Cystic Fibrosis (CF) is a degenerative disease, which causes thickening of the airway surface liquid and reduced mucociliary clearance, which provides an ideal habitat for bacterial infections. Early treatment of CF in children can prevent chronic infection, improve quality of life, and increase life expectancy. The most predominant bacteria found in CF-diseased lungs is Pseudomonas aeruginosa (Pa), which can be treated with inhaled tobramycin. Excipient enhanced growth (EEG) powder formulations are well suited for administering tobramycin to children, as the EEG approach provides minimal upper airway loss and targeted drug delivery. This method uses an initially small aerosol for high …
Quantification And Modeling Of Bladder Biomechanics Mechanisms Linking Spontaneous Rhythmic Contractions And Dynamic Elasticity To Detrusor Overactivity, Zachary E. Cullingsworth
Quantification And Modeling Of Bladder Biomechanics Mechanisms Linking Spontaneous Rhythmic Contractions And Dynamic Elasticity To Detrusor Overactivity, Zachary E. Cullingsworth
Theses and Dissertations
Overactive bladder (OAB) is a chronic condition affecting approximately 20% of adults in the United States. Detrusor overactivity (DO) is the presence of non-voiding contractions in the detrusor (bladder) muscle during filling and is present in some individuals with OAB. DO is currently identified visually during a urodynamics (UD) study involving pressure catheters and filling and voiding of the bladder to evaluate function. UD provides limited subtyping of DO, and an incomplete understanding of mechanisms contributing to OAB.
Aim 1 of this study was to develop objective tools to quantify, subgroup and better understand …
Sound Propagation In Viscous Flows Using Piezoelectric Sensors And Non-Destructive Propagation Techniques And Its Applications, Ahmed M. Abdulkareem
Sound Propagation In Viscous Flows Using Piezoelectric Sensors And Non-Destructive Propagation Techniques And Its Applications, Ahmed M. Abdulkareem
Theses and Dissertations
Structural non-destructive evaluation techniques are applied to viscous flows to detect fluid property changes. The main operating principle consists of an actuator which provides a stimulus, and a sensor to receive a signal traveling to a fluid domain. The main challenge of the operating principle consists of investigating waves traveling in a viscous flow. Traveling waves utilizing a piezoelectric actuator-sensor pair are modeled and the results are validated experimentally. ANSYS models, coupled with a two-way fluid-solid interaction model, are built to investigate how far a signal travels and what frequency ranges are of interest. The numerical model includes modeling three …
A Numerical And Experimental Study On Effect Of Composition Of Ar-N2 Shielding Gas On The Weld Bead Profile And Its Prediction For Hot Wire Arc Additive Manufacturing, Niraj Pudasaini
College of Graduate Studies: Theses & Dissertations
Wire arc additive manufacturing is a process of making three-dimensional metal parts in a layer-by-layer approach using a feed wire and electric arc as a heat source. Wire arc additive manufacturing (WAAM) is becoming more popular due to its ability to create complex 3D parts, less build time, high deposition rate, and significant cost savings. Out of the many parameters used in WAAM, one of the important parameters is shielding gas which plays a significant role in material quality, properties, and defects. In this study, a controlled amount of Argon (Ar) and Nitrogen (N2) shielding gases are used …
อิทธิพลของการใช้บริการ Cu Toyota Ha:Mo ที่ส่งผลกระทบต่อการเดินทางภายในจุฬาลงกรณ์มหาวิทยาลัย, ธนพนธ์ มธุรเวช
อิทธิพลของการใช้บริการ Cu Toyota Ha:Mo ที่ส่งผลกระทบต่อการเดินทางภายในจุฬาลงกรณ์มหาวิทยาลัย, ธนพนธ์ มธุรเวช
Chulalongkorn University Theses and Dissertations (Chula ETD)
การวิจัยนี้มีจุดประสงค์เพื่อศึกษาอิสระและทางเลือกในการเดินทาง โดยในการศึกษานี้จะพิจารณาความแตกต่างของบริเวณพื้นที่ทั้งบริเวณที่มีสถานีบริการ Ha:mo และบริเวณที่ไม่มีสถานีบริการ Ha:mo เพื่อให้ทราบถึงผลจากการพัฒนาของพื้นที่ดังกล่าว การศึกษานี้ใช้ดัชนีชี้วัดการเข้าถึงพื้นที่ โดยแสดงผลลัพธ์ในรูปแบบของโครงข่ายปริภูมิ การเก็บข้อมูลได้จากกลุ่มผู้ใช้บริการ Ha:mo ในระยะยาว ตั้งแต่เดือน ตุลาคม - พฤศจิกายน พ.ศ. 2562 จํานวน 3,587 ข้อมูล ในขณะนั้นมีสถานีบริการ Ha:mo ทั้งหมด 22 สถานี และมีการเก็บข้อมูลในสถานการณ์เดินทางจริง จากรูปแบบการเดินทางต่าง ๆ ได้แก่ การเดิน, การใช้รถโดยสารสาธารณะประจําทาง, การใช้รถ ปอ.พ. ของจุฬาลงกรณ์มหาวิทยาลัย และการใช้บริการ Ha:mo จากผลการวิเคราะห์ พบว่า การใช้บริการ Ha:mo สามารถอํานวยความสะดวกในการเดินทางได้มากกว่าการใช้รถโดยสารสาธารณะ และรถ ปอ.พ. ของจุฬาลงกรณ์มหาวิทยาลัย ผู้เดินทางที่กําลังวางแผนจะเดินทางด้วยระบบขนส่งสาธารณะ จะมีช่วงเวลาในการเดินทางที่นานกว่าปกติ ในขณะที่ ผู้เดินทางที่ กําลังรออยู่ที่ป้ายโดยสาร ก็จะต้องใช้เวลาในการรอค่อนข้างนานเช่นเดียวกัน หากมีจํานวนเที่ยวรถโดยสารที่ ให้บริการไม่เพียงพอ ก็จะต้องใช้เวลาในการรอที่นานขึ้น ในขณะที่ การเลือกใช้บริการ Ha:mo ในการเดินทาง โดยยอมจ่ายอัตราค่าบริการสูงกว่ารถโดยสารสาธารณะ หรือรถ ปอ.พ.ของจุฬาลงกรณ์มหาวิทยาลัย สามารถอํานวยความสะดวกได้มากกว่า รวมถึงยังส่งผลทำให้เพิ่มระยะการเดินทางส่วนบุคคลอีกด้วย นอกจากนี้ การศึกษานี้ได้สำรวจข้อมูล First-Last Mile Travel จากกลุ่มผู้ใช้บริการ Ha:mo ตั้งแต่ เดือนกันยายน – พฤศจิกายน พ.ศ. 2563 โดยใช้การสํารวจแบบ Stated Preference ผลการวิเคราะห์ข้อมูลจากกลุ่มตัวอย่างจํานวน 149 ตัวอย่าง พบว่า การใช้บริการ Ha:mo ส่งผลกระตุ้นการเดินเพื่อมาใช้บริการ Ha:mo ในปริมาณที่มากกว่าการเดินเพื่อไปใช้ระบบขนส่งสาธารณะ และบทบาทของการใช้บริการ Ha:mo ในพื้นที่การศึกษาต่อระบบขนส่งสาธารณะ มีหลากหลายขึ้นอยู่กับวัตถุประสงค์ในการเดินทาง ซึ่งการใช้บริการ Ha:mo สามารถทดแทนการใช้ ระบบขนส่งสาธารณะได้ 30%, เดินทางเพื่อเข้ามาในพื้นที่การศึกษา 24%, เดินทางออกจากพื้นที่การศึกษา 22%, …
Analysis Of Mechanical Deformation Eect On The Voltage Generation Of A Vertical Contact Mode Triboelectric Generator, Nabid Aunjum Hossain, Mir Jalil Razavi, Shahrzad Towfighian
Analysis Of Mechanical Deformation Eect On The Voltage Generation Of A Vertical Contact Mode Triboelectric Generator, Nabid Aunjum Hossain, Mir Jalil Razavi, Shahrzad Towfighian
Mechanical Engineering Faculty Scholarship
One of the associated factors that controls the performance of a triboelectric generator (TEG) is the mechanical deformation of the dielectric layer. Therefore, a good contact model can be a prominent tool to find a more realistic and efficient way of determining the relationships between the contact and electrical output of the generator. In this study, experiments are conducted on a vertical contact mode triboelectric generator under an MTS machine. The open-circuit voltages are measured at different loads imposed by the MTS by controlling the cyclic displacement of the top tribo layer of the generator. A finite-element-based theoretical model is …
Reliability Estimation Of Rotary Lip Seal In Aircraft Utility System Based On Time-Varying Dependence Degradation Model And Its Experimental Validation, Chao Zhang, Rentong Chen, Guanghan Bai, Shaoping Wang, Mileta M. Tomovic
Reliability Estimation Of Rotary Lip Seal In Aircraft Utility System Based On Time-Varying Dependence Degradation Model And Its Experimental Validation, Chao Zhang, Rentong Chen, Guanghan Bai, Shaoping Wang, Mileta M. Tomovic
Engineering Technology Faculty Publications
With several attractive properties, rotary lip seals are widely used in aircraft utility system, and their reliability estimation has drawn more and more attention. This work proposes a reliability estimation approach based on time-varying dependence analysis. The dependence between the two performance indicators of rotary lip seals, namely leakage rate and friction torque, is modeled by time-varying copula function with polynomial to denote the time-varying parameters, and an efficient copula selection approach is utilized to select the optimal copula function. Parameter estimation is carried out based on a Bayesian method and the reliability during the whole lifetime is calculated based …
Mems Biosensor For Water-Immersed Application, Kun-Lin Lee
Mems Biosensor For Water-Immersed Application, Kun-Lin Lee
Dissertations and Theses
Although many air-based sensing mechanisms exist, not all of them can be applied in the water-based environment. In order to obtain a cell-based biosensor, the sensing method needs to be reliable and repeatable in a liquid environment. Therefore, this study is focused on transforming existing air-based sensors to water-immersed applications. This study includes two types of sensors.
First, commercial quartz resonators are used to investigate live-cell activity in water-based toxic solutions. I perform toxicity tests using quartz crystal microbalance (QCM). The QCM used in the study has a resonant frequency of 10 MHz and consists of an AT-cut quartz crystal …
A Micromechanics Study On Ferroelectrics And Multiferroic Composites, Zhiming Hu
A Micromechanics Study On Ferroelectrics And Multiferroic Composites, Zhiming Hu
Dissertations and Theses
Two kinds of modern composites are studied in this thesis. One is ferroelectric materials, and the other is the multiferroic composites. Based upon the essential properties of these two types materials, several issues need to be considered in order to study their effective properties. For example, the microstructures of the system including the shape, size and the distribution; the phase connectivity; and the loading conditions will impact the results. First, we focus on the investigation of ferroelectrics and its composites. Based on the experimental observations, the nonlinear electromechanical coupling responses of ferroelectrics are strongly depending on the frequency of the …
Adapting To Extreme Heat: Social, Atmospheric, And Infrastructure Impacts Of Air Conditioning In Megacities - The Case Of New York City, Harold Gamarro
Adapting To Extreme Heat: Social, Atmospheric, And Infrastructure Impacts Of Air Conditioning In Megacities - The Case Of New York City, Harold Gamarro
Dissertations and Theses
Extreme heat events are becoming more frequent and intense in most large cities. Built-up surfaces also limit cooling mechanisms, leading to warmer conditions in cities, a phenomenon called the Urban Heat Island (UHI). This presents major challenges to reduce adverse health effects of hot weather, particularly in vulnerable populations like the elderly and low-income communities. Here we explore the overall impacts of increasing air conditioning (AC) system adoption in residences as an adaptive measure to reduce human health risks under heat waves, with New York City (NYC) as a case study. This study uses AC adoption data from the 2017 …
Capillary Forces And Wetting Dynamics By Diffuse-Interface Modeling, Fanny Thomas
Capillary Forces And Wetting Dynamics By Diffuse-Interface Modeling, Fanny Thomas
Dissertations and Theses
Wetting phenomena underlie many natural and industrial processes, from the proper functioning of the lungs to the thin coating of surfaces. The three-phase interactions involved at microscopic scales play a critical role. Adding solid particles to an emulsion, for example, can drastically change the flow behavior due to capillary bridging between the particles. The study of these three-phase systems is especially relevant to the petroleum industry, where gas hydrates forming large clusters in subsea pipelines during crude oil transportation is a major concern. The dynamics of such systems is also of great interest from a fundamental perspective. Indeed describing non-equilibrium …
Toward Closing The Urban Surface Energy Balance Using Satellite Remote Sensing, Joshua Hrisko
Toward Closing The Urban Surface Energy Balance Using Satellite Remote Sensing, Joshua Hrisko
Dissertations and Theses
The energy exchanges at the Earth’s surface are responsible for many of the processes that govern weather, climate, human health, and energy use. This exchange, commonly known as the surface energy balance (SEB), determines the near-surface thermodynamic state by partitioning the available energy into surface fluxes. The net all-wave radiation is often the primary energy source, while the heat storage and sensible and latent heat fluxes account for the majority of energy distributed elsewhere. While the SEB of various natural environments(trees, crops, soils) has been well-observed and modeled, the urban surface energy balance remains elusive. This is due to the …
On The Energy Sustainability Of Active And Passive Building Integrated Technologies In The Context Of A Changing Climate For Tropical Coastal Cities, Rabindra Pokhrel
On The Energy Sustainability Of Active And Passive Building Integrated Technologies In The Context Of A Changing Climate For Tropical Coastal Cities, Rabindra Pokhrel
Dissertations and Theses
Caribbean Sea surface temperatures have been rising at an alarming rate of 0.020C/year. The effect of rising sea surface temperatures is reflected in increasing in 2m air temperature over the Caribbean. The rise in extreme temperatures increases human discomfort and energy demands for air conditioning (AC) putting both the population and energy infrastructure at higher risk of vulnerability. This vulnerability is amplified in compact cities where anthropogenic heat removal from the built environment further increases the temperature of the urban canyon with feedback on human comfort and energy demands. Although there has been prior work reported on mitigating energy demands …
Modeling And Characterization Of A Pull-In Free Mems Microphone, Mehmet Ozdogan, Shahrzad Towfighian, Ronald Miles
Modeling And Characterization Of A Pull-In Free Mems Microphone, Mehmet Ozdogan, Shahrzad Towfighian, Ronald Miles
Mechanical Engineering Faculty Scholarship
In this study, we examine the feasibility of designing a MEMS microphone employing a levitation based electrode configuration. This electrode scheme enables capacitive MEMS sensors that could work for large bias voltages without pullin failure. Our experiments and simulations indicate that it is possible to create robust sensors properly working at high DC voltages, which is not feasible for most of the conventional parallel plate electrode-based micro-scale devices. In addition, the use of larger bias voltages will improve signal-to-noise ratios in MEMS sensors because it increases the signal relative to the noise in read-out circuits. This study presents the design, …
Lateral Pull-In Instability Of Electrostatic Mems Transducers Employing Repulsive Force, Meysam Daeichin, Ronald Miles, Shahrzad Towfighian
Lateral Pull-In Instability Of Electrostatic Mems Transducers Employing Repulsive Force, Meysam Daeichin, Ronald Miles, Shahrzad Towfighian
Mechanical Engineering Faculty Scholarship
We report on the lateral pull-in in capacitive MEMS transducers that employ a repulsive electrostatic force. The moving element in this system undergoes motion in two dimensions. A two degree-offreedom mathematical model is developed to investigate the pull-in quantitatively. The nonlinear electrostatic force, which is a vector function of two spatial coordinates, is determined by calculating the potential energy of the system using a boundary element approach. The equilibrium points are found by numerically solving the nonlinear coupled static equations. A stability analysis reveals that depending on the values of the lateral and transverse stiness, the system undergoes dierent bifurcations …
An Extensive Set Of Kinematic And Kinetic Data For Individuals With Intact Limbs And Transfemoral Prosthesis Users, Seyed Abolfazl Fakoorian, Arash Roshanineshat, Poya Khalaf, Vahid Azimi, Daniel J. Simon, Elizabeth Hardin
An Extensive Set Of Kinematic And Kinetic Data For Individuals With Intact Limbs And Transfemoral Prosthesis Users, Seyed Abolfazl Fakoorian, Arash Roshanineshat, Poya Khalaf, Vahid Azimi, Daniel J. Simon, Elizabeth Hardin
Electrical and Computer Engineering Faculty Publications
This paper introduces an extensive human motion data set for typical activities of daily living. These data are crucial for the design and control of prosthetic devices for transfemoral prosthesis users. This data set was collected from seven individuals, including five individuals with intact limbs and two transfemoral prosthesis users. These data include the following types of movements: (1) walking at three different speeds; (2) walking up and down a 5-degree ramp; (3) stepping up and down; (4) sitting down and standing up. We provide full-body marker trajectories and ground reaction forces (GRFs) as well as joint angles, joint velocities, …
Comparative Evaluation Of Carbon Reinforced Polyetherketone Acetabular Cup Using Finite Element Analysis, A. Abdal, Rafiqul Noorani, G. Cha
Comparative Evaluation Of Carbon Reinforced Polyetherketone Acetabular Cup Using Finite Element Analysis, A. Abdal, Rafiqul Noorani, G. Cha
Mechanical Engineering Faculty Works
Background: Patients suffering from osteoarthritis undergo surgery to replace hip joints with hip prosthesis implants. Today most acetabular cups of hip prostheses are made of Ultra-High-Molecular-Weight-Polyethylene. However, these materials acting as acetabular cups of the implant have been recalled since patients have been feeling uncomfortable and abstained from physical activities. A newly introduced material, 30% Carbon Reinforced Polyetherketone, possess better isotropic mechanical properties and lower wear rates.
Objective: The research aims to compare the von-Mises stresses and deformation in static and dynamic loading of Ultra-High Molecular-Weight-Polyethylene to 30% Reinforced Carbon Fiber Polyetherketone using Finite Element Analysis.
Material and Methods: An …
Real-Time Instance Segmentation And Point Cloud Extraction For Japanese Food Using Rgb-D Camera, Suthiwat Yarnchalothorn
Real-Time Instance Segmentation And Point Cloud Extraction For Japanese Food Using Rgb-D Camera, Suthiwat Yarnchalothorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Innovation in technology is playing an important role in the development of food industry, as is indicated by the growing number of food review and food delivery applications. Similarly, it is expected that the process of producing and packaging food itself will become increasingly automated using a robotic system. The shift towards food automation would help ensure quality control of food products and improve production line efficiency. One key enabler for such automated system is the ability to detect and classify food object with great accuracy and speed. In this study, we explore real-time food object segmentation using RGB-D depth …
การศึกษาการใช้พลังงานของระบบปรับอากาศแบบแยกส่วนสำหรับร้านสะดวกซื้อ, ไกรวิชญ์ เศาภายน
การศึกษาการใช้พลังงานของระบบปรับอากาศแบบแยกส่วนสำหรับร้านสะดวกซื้อ, ไกรวิชญ์ เศาภายน
Chulalongkorn University Theses and Dissertations (Chula ETD)
ปัจจุบันประชากรในประเทศไทยนิยมเลือกใช้บริการร้านสะดวกซื้อมากขึ้น เนื่องจากร้านสะดวกซื้อมีทำเลที่ตั้งที่เข้าถึงได้อย่างสะดวกรวดเร็วเหมาะสมกับการใช้ชีวิตประจำวัน ดังนั้นการเลือกระบบปรับอากาศที่มีความเหมาะสมกับร้านสะดวกซื้อจึงเป็นสิ่งที่สำคัญในเรื่องการจัดการการใช้พลังงานของร้านสะดวกซื้อ งานวิจัยนี้มีจุดมุ่งหมายในการวิเคราะห์การใช้พลังงานของระบบปรับอากาศแบบแยกส่วนสำหรับร้านสะดวกซื้อ ซึ่งเป็นระบบปรับอากาศที่พบว่ามีการใช้งานภายในร้านสะดวกซื้อเป็นส่วนใหญ่ในสภาพอากาศแบบร้อนชื้น โดยการเปรียบเทียบการใช้พลังงานของค่าพารามิเตอร์ต่าง ๆ ในลักษณะของค่าเฉลี่ย ได้แก่ อุณหภูมิ ความชื้นสัมพัทธ์ กำลังไฟฟ้า และการใช้พลังงาน สามารถแบ่งการวิเคราะห์การใช้พลังงานได้ 2 รูปแบบ คือ การวิเคราะห์การใช้พลังงานในแต่ละโซนอุณหภูมิและการวิเคราะห์การใช้พลังงานในแต่ละเดือนของร้านสะดวกซื้อ ในการคำนวณการทำงานของระบบปรับอากาศตลอดทั้งปีนั้นจะใช้โปรแกรม EnergyPlus และโปรแกรม Openstudio โดยจะทำการจำลองพลังงานของระบบปรับอากาศสำหรับร้านสะดวกซื้อ โดยตัวอาคารแห่งนี้มีลักษณะเป็นสี่เหลี่ยมผืนผ้า อาคารเดี่ยว 1 ชั้น ติดตั้งระบปรับอากาศแบบแยกส่วนอยู่ภายในทั้งหมด 4 เครื่อง ในการสร้างโมเดลของร้านสะดวกซื้อจำลองแห่งนี้อ้างอิงจากแบบพิมพ์เขียวของร้านสะดวกซื้อและสร้างขึ้นโดยโปรแกรม SketchUp โดยนำข้อมูลสภาพอากาศที่ใช้ในการจำลองพลังงานจากกรมอุตุนิยมวิทยา สำหรับวัตถุประสงค์ในการเปรียบเทียบการใช้พลังงานของระบบปรับอากาศแบบแยกส่วน จะใช้ข้อมูลแผ่นข้อมูลจำเพาะของอุปกรณ์ที่อยู่ในระบบปรับอากาศที่มีการติดตั้งและใช้งานจริง ผลของการเปรียบเทียบค่าพารามิเตอร์ต่าง ๆ จากการแบ่งโซนอุณหภูมิ 8 ตำแหน่ง สามารถสรุปได้ 3 กลุ่ม คือ โซนที่อยู่บริเวณด้านหน้า ตรงกลาง และด้านหลังของร้านสะดวกซื้อ ซึ่งขึ้นอยู่กับตำแหน่งการติดตั้งเครื่องปรับอากาศ พบว่า บริเวณจุดอับลมมีสัดส่วนการใช้พลังงานสูงที่สุดคิดเป็นร้อยละ 28.1 และ 28.7 และสัดส่วนการใช้พลังงานตลอดทั้งปีของอุปกรณ์ต่าง ๆ ได้แก่ เครื่องปรับอากาศแบบแยกส่วน ตู้เย็น อุปกรณ์ต่าง ๆ และระบบแสงสว่าง คิดเป็นร้อยละ 15.8 39.5 22.3 และ 22.4 ตามลำดับ ถึงแม้จะพบว่าสัดส่วนการใช้พลังงานของระบบปรับอากาศแบบแยกส่วนมีค่าน้อยที่สุด แต่ก็ยังส่งผลกระทบต่อโซนอุณหภูมินั้น ๆ อีกด้วย โดยการใช้พลังงานโดยรวมของร้านสะดวกซื้อในเดือนมีนาคมมีค่ามากที่สุดเมื่อเปรียบเทียบตลอดทั้งปี นอกจากนี้การใช้พลังงานโดยรวมในแต่ละโซนอุณหภูมิต่อพื้นที่ใช้งานจริงสำหรับพื้นที่ปรับอากาศและสำหรับพื้นที่ทั้งหมดของร้านสะดวกซื้อตลอดทั้งปี มีค่าเท่ากับ 429.32 และ 403.22 kWh/m2 ตามลำดับ และยังพบว่า เดือนมีนาคมมีค่ามากที่สุด เท่ากับ 34.90 kWh/m2 ซึ่งมีความสอดคล้องกับการวิเคราะห์ผลการใช้พลังงานในแต่ละเดือนของร้านสะดวกซื้อแห่งนี้อีกด้วย