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Articles 1 - 17 of 17
Full-Text Articles in Engineering
Multivariate Calibration Of A Load Sensor For Dynamic And Static Freight Railcar Applications, Dylan Michael Blackwell
Multivariate Calibration Of A Load Sensor For Dynamic And Static Freight Railcar Applications, Dylan Michael Blackwell
Theses and Dissertations
Determination of the load carried by each bearing in a railcar system is crucial to the integrity of the railroad industry. With accurate load measurement, the process of filling a railcar with its specified cargo can be optimized to provide the maximum amount of cargo without exceeding the upper weight limits imposed by the Associations of American Railroads (AAR). An accurate load measurement will additionally make it possible to identify any load imbalance that occurs during periods of travel which result in having a detrimental effect on the health of the bearing. Previous work conducted with a strain-gauge load sensor …
Forcespinning®: An Alternative Method To Fabricate Metal Oxide/Carbon Composite Nanofiber Anodes For Li-Ion Batteries, Luis Zuniga
Forcespinning®: An Alternative Method To Fabricate Metal Oxide/Carbon Composite Nanofiber Anodes For Li-Ion Batteries, Luis Zuniga
Theses and Dissertations
Metals and their respective oxides have been highly regarded as next generation anode materials for lithium-ion batteries (LIBs). In this research work the electrochemical performance of Sn, SnO2, and TiO2. With the advantages of nanotechnology and the Forcespinning® method of fabricating micro and nanofibers, binder-free anodes are produced from metal or metal oxide/carbon composite microfibers. Through these microfibers the electrochemical performance of the above mentioned materials are significantly improved due to the increased surface area per volume providing a large number of reaction sites for the anode materials. Further performance enhancement was achieved by also modifying the fiber microstructure to …
Optimizing Border Security With Stochastic And Deterministic Strategies, Gabriel A. Rueda
Optimizing Border Security With Stochastic And Deterministic Strategies, Gabriel A. Rueda
Theses and Dissertations
International trade and border security have always been linked together, and so has the need to find ways to improve security decisions. The United States and bordering countries benefit from the North American Free Trade Agreement (NAFTA), but amongst the positive effects of NAFTA there is a looming drug threat that effects the bi-national supply chains. In 2015 Customs and Border Protections (CBP) processed over 72,000 trucks, rail, and sea containers a day. CBP also seized 3.4 million pounds of narcotics, the majority of them at the ports of entry. With unknown threats using commercial vehicles to transport their illicit …
Wettability Of Nonwoven Polymeric Nanofiber Mats, Edgar Munoz
Wettability Of Nonwoven Polymeric Nanofiber Mats, Edgar Munoz
Theses and Dissertations
The wettability of heterogeneous materials has been attracting special interest by academia and industrial sector given the need to development self-cleaning Nonwoven nanofiber mats have demonstrated potential given its hydrophobicity granted by the ultimate structure of the system, small fiber diameter and small pores giving rise to effects such as the Cassie-Baxter. This thesis analyzed the wettability of a wide range of polymeric systems. Nanofiber mats were manufactured using the Forcespinning® technology. Samples were prepared at different polymeric concentrations and rotational speeds to alter fiber size; density of the mat was also altered to evaluate the effect of porosity on …
Knee Joint Internal Forces During Squat Jump Exercise, Ricardo Moreno
Knee Joint Internal Forces During Squat Jump Exercise, Ricardo Moreno
Theses and Dissertations
The purpose of this research is to investigate muscular ligament and joint contact forces produced during squat jump exercise. An inverse dynamics, two dimensional, leg model is used to describe the motion in the sagittal plane. The lower extremity model includes two bones, tibia and femur, tibio-femoral ligaments, and muscles such as quadriceps, hamstrings, and gastrocnemius. The ligaments are anatomically modeled as nonlinear strings, but the femoral condyle is modeled as a circle and the tibial plateau as a straight line. Experimental squat jump exercises are conducted to obtain the ground reaction forces, the angular accelerations, and centroid linear acceleration …
Development Of A Fundamental Autonomous Ground Vehicle Cruise Control Using Matlab And Simulink, Luis F. Martinez
Development Of A Fundamental Autonomous Ground Vehicle Cruise Control Using Matlab And Simulink, Luis F. Martinez
Theses and Dissertations
This study presents and describes the development of a fully autonomous vehicle cruise control system covering the vehicle dynamics and control design needed to simulate such system. It encompasses obstacle avoidance, intelligent-and-optimal lane change as well as adaptive behavior. This study offers a comprehensive two-dimensional cruise control with three degrees of freedom and it is designed using active obstacle avoidance controllers. It also includes optimized fuzzy logic for optimal vehicle trajectory and an extensive array of control law methodology. The end work shows a complete simulation run using MATLAB and Simulink.
Study Of Selective Laser Remelting Of 316l S.S. To Reduce Roughness On Inclined Surface, Jafar Ghorbani
Study Of Selective Laser Remelting Of 316l S.S. To Reduce Roughness On Inclined Surface, Jafar Ghorbani
Theses and Dissertations
Additive manufacturing (AM) technologies are increasingly competing with subtractive methods, and there are promising applications for additive technologies that are hybrid with traditional manufacturing methods. Poor surface roughness of additive manufactured parts continues to be a major challenge especially for advanced functional parts. In this study, effect of processing parameters are evaluated, optimized and verified by using the Box–Behnken design of experiment method. The results, for the first time, reveal that surface remelting has the potential to become a high speed approach for improving the roughness of non-horizontal surface of additive manufactured parts.
Front Dynamics And Entrainment Of Finite Circular Gravity Currents On An Unbounded Uniform Slope, Nadim Zgheib, A. Ooi, S. Balachandar
Front Dynamics And Entrainment Of Finite Circular Gravity Currents On An Unbounded Uniform Slope, Nadim Zgheib, A. Ooi, S. Balachandar
Mechanical Engineering Faculty Publications and Presentations
We report on the dynamics of circular finite-release Boussinesq gravity currents on a uniform slope. The study comprises a series of highly resolved direct numerical simulations for a range of slope angles between 5∘ and 20∘ . The simulations were fixed at Reynolds number Re=5000 for all slopes considered. The temporal evolution of the front is compared to available experimental data. One of the interesting aspects of this study is the detection of a converging flow towards the centre of the gravity current. This converging flow is a result of the finite volume of the release coupled with the presence …
Temperature Profiles Of Railroad Tapered Roller Bearings With Defective Inner And Outer Rings, Constantine Tarawneh, Luz Sotelo, Anthony A. Villarreal, Nancy De Los Santos, Ryan L. Lechtenberg, Robert Jones
Temperature Profiles Of Railroad Tapered Roller Bearings With Defective Inner And Outer Rings, Constantine Tarawneh, Luz Sotelo, Anthony A. Villarreal, Nancy De Los Santos, Ryan L. Lechtenberg, Robert Jones
Mechanical Engineering Faculty Publications and Presentations
In the railroad industry, monitoring the condition of key components such as bearings and wheels is vital to ensure the safe transport of goods and commodities. Bearing seizures are amongst the most dangerous types of failures experienced by trains because they occur unexpectedly and may lead to costly derailments. Current bearing health monitoring techniques include tracking the temperature and acoustic emissions given by the bearings. Although temperature histories of railroad tapered roller bearings are readily available, the literature does not provide information relating the temperature profiles to the severity of the bearing defect. The study presented here investigates the correlation …
Heat Generation In The Railroad Bearing Thermoplastic Elastomer Suspension Element, Oscar O. Rodriguez, Juan Carbone, Arturo A. Fuentes, Robert E. Jones, Constantine Tarawneh
Heat Generation In The Railroad Bearing Thermoplastic Elastomer Suspension Element, Oscar O. Rodriguez, Juan Carbone, Arturo A. Fuentes, Robert E. Jones, Constantine Tarawneh
Mechanical Engineering Faculty Publications and Presentations
The main purpose of this ongoing study is to investigate the effect of heat generation within a railroad thermoplastic elastomer suspension element on the thermal behavior of the railroad bearing assembly. Specifically, the purpose of this project is to quantify the heat generated by cyclic loading of the elastomer suspension element as a function of load amplitude, loading frequency, and operating temperature. The contribution of the elastomer pad to the system energy balance is modeled using data from dynamic mechanical analysis (DMA) of the specific materials in use for that part. DMA is a technique that is commonly used to …
Design Of Three-Dimensional Near-Zero Refractive Index Metamaterials, David Flores Iii
Design Of Three-Dimensional Near-Zero Refractive Index Metamaterials, David Flores Iii
Theses and Dissertations
Near-zero refractive index metamaterials exhibit remarkable electromagnetic properties which can and will be applied in the near future. From the known methods of achieving near-zero refractive index, this work primarily focuses on the design of 3D metamaterials whose permittivity and permeability are both close to zero while maintaining relatively low loss factor. The design of the metamaterials is based on the chiral shape “omega” and designed to weave periodically as a fishnet. Theoretical analysis, computer modeling and simulation are steps taken in the design of metamaterials. A computational tool based on the robust method for effective parameter extraction is successfully …
Graphene-Based Nanomaterials For Hydrogen Generation And Storage, Lin Wei
Graphene-Based Nanomaterials For Hydrogen Generation And Storage, Lin Wei
Theses and Dissertations
Hydrogen energy is promising candidate to replace fossil fuel. However, the usage of hydrogen energy was greatly limited due to its generation and storage. In this thesis report, the author synthesized novel metal/carbon nanomaterials used for the hydrogen storage and hydrogen evolution reaction. These materials were characterization by XRD, Raman, XPS, SEM, EDX, etc. And the surface area and the hydrogen storage properties were tested by ASAP 2020, using the BET measurement and hydrogen isotherm curves to discuss the gas adsorption properties. As for hydrogen evolution reaction, the materials were made into electrodes and tested with LSV, CV to shows …
Thermal Conductivity Measurements Of Nanomaterials, Javier Acosta Martinez
Thermal Conductivity Measurements Of Nanomaterials, Javier Acosta Martinez
Theses and Dissertations
Thermal conductivity “k” can be defined as a material property where heat is diffused due to a temperature gradient within the material. Among the applications for thermal conductivity are: thermoelectrics, thermal interface materials, thin films, insulation, among many others. A study was made to compare the different types of studies of thermal conductivity of nanomaterials, as well as, a comparison among the different types of setups used to measure thermal conductivity. For this study a custom made thermal conductivity tester was built, this tester was validated by measuring materials with both low and high thermal conductivity, and comparing the results …
Nonlinear Dynamics Of Electrostatically Actuated Nanotweezers, Bin Liu
Nonlinear Dynamics Of Electrostatically Actuated Nanotweezers, Bin Liu
Theses and Dissertations
Bin Liu, Nonlinear Dynamics of Electrostatically Actuated Nanotweezers. Master of Science (MS), May 2016, 77 pp, 6 tables, 59 figures, references, 25 titles. The amplitude-frequency response of electrostatic nanotube nanotweezer device system is investigated; soft alter current was setting at near half natural frequency impulse on nanotubes which are referred to as two arms, parametric and primary resonances will be shown in the results, respectively. Firstly we are using the Method of Multiple Scales (MMS) analytical model; results will be compared with Reduced Order Model (ROM). By variation and comparison of multiple parameters including van der wall molecular forces, electrostatic …
Parametric Analysis Of A Solid Oxide Fuel Cell Auxiliary Power Unit Operating On Syngas Produced By Autothermal Reforming Of Hydrocarbon Fuels, Jun Dong, Xinhai Xu, Ben Xu, Shuyang Zhang
Parametric Analysis Of A Solid Oxide Fuel Cell Auxiliary Power Unit Operating On Syngas Produced By Autothermal Reforming Of Hydrocarbon Fuels, Jun Dong, Xinhai Xu, Ben Xu, Shuyang Zhang
Mechanical Engineering Faculty Publications and Presentations
A 1 kWe integrated auxiliary power unit (APU) system consisting of an autothermal reformer and a solid oxide fuel cell (SOFC) unit, as well as balance-of-plant components, was designed and analyzed. A relatively easy-to-approach SOFC model was developed in order to conveniently calculate V-I and P-I curves and the system's net efficiency at different operating conditions. The effects of steam to carbon and oxygen to carbon ratios in the reactants, channel dimensions of the SOFC unit, and hydrocarbon fuel types on the integrated APU system's performance were discussed. Five hydrocarbon fuels including diesel, Jet-A, gasoline, ethanol, and methanol were studied …
Parametric Investigations Into Internal Surface Modification Of Brass Tubes With Alternating Magnetic Field, Harish Kumar, Sehijpal Singh, Anil K. Srivastava
Parametric Investigations Into Internal Surface Modification Of Brass Tubes With Alternating Magnetic Field, Harish Kumar, Sehijpal Singh, Anil K. Srivastava
Manufacturing & Industrial Engineering Faculty Publications and Presentations
The final finish operations have great significance in an overall manufacturing cycle of a product. The surface finishing and modification of surfaces have been the vital requirements of most of the products. The processes like shot peening, shot blasting, abrasive finishing and super finishing are being largely employed for such requirements. While final finishing of flat and outside surfaces are relatively easy and well established, the internal surfaces such as those of pipes is not so simple. In this paper, the application of low frequency alternative magnetic field has been explored for imparting surface modification including surface on the internal …
Knee Internal Forces In Moderate Squat Exercise, Dumitru I. Caruntu, Jose Mario Salinas
Knee Internal Forces In Moderate Squat Exercise, Dumitru I. Caruntu, Jose Mario Salinas
Mechanical Engineering Faculty Publications and Presentations
This paper deals with internal forces of human knee during moderate squat exercise. The moderate squat exercise consists of a descending phase from standing to the lowest position (largest flexion angle) in which no significant contact between thigh and calf occurs, and an ascending phase back to standing position. This research predicts the internal forces such as muscle forces, contact forces, and ligamentous forces. The ligamentous structures in this research consist of Anterior Cruciate Ligament (ACL), Posterior Cruciate Ligament (PCL), Lateral Collateral Ligament (LCL), and Medial Collateral Ligament (MCL). The ligaments are modeled as nonlinear elastic strips (they do not …