Engineering Commons^™

Fluid Phase Separation Via Nanochannel Array, John Lee

Graduate Theses and Dissertations

Microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) generate ideas and techniques for creating new devices at the micro/nano scale. This dissertation study designed a gas generator system utilizing nanochannels for phase separation that is useful for micro-pneumatic actuators, micro-valves, and micro-pumps. The new gas generator has the potential to be an integral part of a propulsion system for small-scale satellites. Nano/picosatellites have limited orientation capability partly due to the current limitations of microthruster devices. Development of a self-contained micro propulsion system enables dynamic orbital maneuvering of pico- and nano-class satellites.

Additionally, the new gas generator utilizes a high efficiency, green …

The Intrinsic Properties Of Reconstituted Soils, Nabeel Shaker Mahmood

Graduate Theses and Dissertations

Reconstituted specimens are often utilized to characterize engineering properties of cohesive soils. A series of undrained triaxial tests were conducted on reconstituted soil specimens to evaluate 1) the influence of stress path, 2) the intrinsic shear strength behavior, and 3) the small-strain characteristics. The stress path tests were conducted on kaolinite specimens reconstituted from slurries with water content values of one and one-half times the liquid limit of the soil (1.5LL). To evaluate the intrinsic undrained shear strength and the intrinsic small-strain properties, the triaxial tests were performed on kaolinite and illite specimens that were reconstituted at two levels of …

Thermoelectrics And Thermoelectric Devices, Benjamin T. Erck

Senior Theses

The field of thermoelectrics has many applications, and more are found in everyday systems. From its current studies, it is apparent that improving the figure of merit zT (which defines a good thermoelectric material) is important in the effectiveness of power generation. Another important part of thermoelectrics is the duality of these devices. They can both move heat and generate power, depending on their role in the system. In this thesis research, a process was made to test these thermoelectric relationships for a few Peltier devices in order to understand their efficiencies and what systems they can be applied to.

Adam J. Liska: Curriculum Vitae, Adam Liska

Adam Liska Papers

Associate Professor, George Dempster Smith Chair of Industrial Ecology, Departments of Biological Systems Engineering and Agronomy & Horticulture, University of Nebraska-Lincoln 236 L.W. Chase Hall, Lincoln, NE 68583-0726, Ph: (402) 472-8744, e-mail: [email protected]

Ph.D. 2003 Biology (magna cum laude), Max Planck Institute of Molecular Cell Biology & Genetics, Technische Universität Dresden, Dresden, Germany

Temperature And Stress Analysis During Tank Decanting And Refilling Process, Zhe Liu

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

In the present work, an analytical expression for the temperature distribution of the cross-section of a natural gas transport tank is derived by time-matching Green’s Function method. The tank decanting process can produce a living temperature decrease inside the tank wall while the filling process can produce a large temperature increase. This behavior can cause damage to the inner layer of the tank. The damage occurs in the form of excessive stress in the wall which is combined mechanical stress and thermal stress. Therefore, thermo-elasticity analysis is another objective of the present work. A simplified mechanical model is established in …

Enginews, May 2018, School Of Computer Science & Engineering

News, Magazines and Reports

Trial and Error: Adjusting to the MakerSpace --Looking Forward: Rube Goldberg Machine.

Innovation In Commercial Supersonic Aircraft With Candidate Engine For Next Generation Supersonic Aircraft, Christopher D. Roper, Jordan Fraser, Alain J. Santos

Senior Design Project For Engineers

The objective of this design study and competition - Next Generation Supersonic Candidate Engine and Aircraft Design, is a response to a proposal and is motivated by NASA’s National Research Announcement in 2006. The requirements of this design study are provided by AIAA (American Institute of Aeronautics and Astronautics). The aircraft designed is a private business class. The aircraft engine performs at a maximum speed of Mach 1.8 and supersonic cruise speed of Mach 1.6 at 55,000 feet and a range of 4000 nmi. A generated mission profile through considerations in flight regime will drive the design involved in the …

Wireless Powered Flexible Gastrostimulator, Souvik Dubey

Electrical Engineering Dissertations - Archive

Gastric electrical stimulation (GES) is an effective alternative to long-term dietary and medicinal treatment for gastroparesis. This work presents the design and development of two miniature implantable battery-less gastrostimulators, operated by wireless radio-frequency power. The devices deliver controlled electrical pulses to the stomach tissues to help regain normal motility. The first prototype was designed with the goal to optimize the wireless power transfer efficiency, various antenna configurations were investigated. The attenuation due to human tissue barrier was examined with an equivalent model. To enable reconfiguring the device to meet the patients' needs after implantation, a novel method of changing the …

Devices To Study Cancer Cell Behavior, Mohammad G. Abdallah

Electrical Engineering Dissertations - Archive

Cancer is a major health concern that effects millions of people worldwide. The main contributing factor to the deadliness of the disease is cancer metastasis, where the cancer cells break away from the primary tumor site, transmigrate through the endothelium, and form secondary tumors in distant areas. Many studies have identified links between the mechanical properties of the cellular microenvironment and the behavior of cancer cells. Also, nanobiotechnology and bioMEMS have had a tremendous impact on biosensing in the areas of cancer cell detection and therapeutics, disease diagnostics, and DNA analysis. Most current technologies enable observation of only the population-level …

Design And Fabrication Of Self-Packaged, Flexible Mems Accelerometer And Aluminum Nitride Tactile Sensors, Md Sohel Mahmood

Electrical Engineering Dissertations - Archive

The work presented in this dissertation describes the design, fabrication and characterization of a Micro Electro Mechanical System (MEMS) capacitive accelerometer on a flexible substrate. To facilitate the bending of the accelerometers and make them mountable on a curved surface, polyimide was used as a flexible substrate. Considering its high glass transition temperature and low thermal expansion coefficient, PI5878G was chosen as the underlying flexible substrate. Three different sizes of accelerometers were designed in CoventorWare® software which utilizes Finite Element Method (FEM) to numerically perform various analyses. Capacitance simulation under acceleration, modal analysis, stress and pull-in study were performed in …

Fabrication Of Solid Polymeric 3d Shapes From Programmable Flat Hydrogel Sheets, Ninad Vilas Khadse

Material Science and Engineering Theses - Archive

Modern methods of fabricating three-dimensional (3D) objects include sheet metal forming, thermoforming, and additive manufacturing among others. These methods have their own advantages and disadvantages regarding scalability, customizability, and time efficiency. A promising approach is to program the growth (expansion and contraction) of hydrogel sheets to form 3D structures. The differential growth-induced 3D shaping approach has the advantages of traditional manufacturing (scalability) and additive manufacturing (customizability). The objective of this study is to create nanocomposite 3D structures that are stable in ambient environment using the growth-induced 3D shaping approach. This study determines the effect of silica nanoparticles in hydrogels on …

Characterization Of Normal And Abnormal Bones By Raman Spectroscopy : Analysis Of Mineral To Matrix Ratio Of Bone Using Advanced Materials Characterization Techniques, Meet Yagnesh Shah

Material Science and Engineering Theses - Archive

Bone disorders and disease are associated with multiple factors. Some of the disorders and diseases are difficult to understand because of their unknown root causes. Our goal was to differentiate between normal and genetically modified rat bone groups by finding the difference in mineral to matrix (Mn/Mx) content using Raman spectroscopy. Raman spectroscopy gives the chemical composition based on the vibration modes of the molecules. Quantitative analysis of Mn/Mx content calculated from Raman spectra allowed us to distinguish between healthy and genetically modified rat bone groups. We have presented the results by averaging the Mn/Mx ratios. Thus, the most significant …

Quantitative Analysis Of Mineral/Matrix To Evaluate Genetically Altered Bone With Infrared Spectroscopy And X-Ray Spectral Imaging, Sunil Balasaheb Yadav

Material Science and Engineering Theses - Archive

This thesis focuses on the characterization of bone with the help of Fourier Transform Infrared Spectroscopy and Energy Dispersive Spectroscopy. Such analysis of the physics and chemistry of biomaterials is vital to resolve problems in life science of bone-related diseases and disorders. Material characterization can help in the understanding of disease mechanisms and lead to useful drugs and other treatments. In this thesis, I have used bone materials produced by groundbreaking research at UT Southwestern Research Center and Texas Scottish Rite Children's Hospital to establish that idiopathic clubfoot (Talipes equinovarus) is associated with the Follistatin 5 gene. We studied healthy …

Experimental Investigation Of Fischer-Tropsch Synthesis With A Modified Catalyst Support, Pawarat Bootpakdeetam

Mechanical and Aerospace Engineering Dissertations - Archive

Energy demand has been rapidly increasing in the last 30 years due to the population growth and high demand by industries. However, as natural energy sources are limited, they cannot meet this increased energy demand. Therefore, alternative energies have become an option to sustain current and future energy demands. One promising and reliable alternative energy is the Fischer-Tropsch synthesis (FTS), which is a gas-to-liquid (GTL) technology that converts syngas from a low-value feedstock, for example, from coal, biomass, or natural gas, into a high-value liquid hydrocarbon. In addition, FTS is a highly exothermic catalytic reaction that requires careful thermal management …

Reconfigurable Electrochemical Biosensor Enabled By Digital Microfluidic Devices, Ali Farzbod

Mechanical and Aerospace Engineering Dissertations - Archive

The increasing demand for improving the health care quality in developed countries with synchronous advances in the microfabrication of CMOS devices results in the emergence of the Lab-on-a-chip (LOC) field. The ultimate goal of LOC's is to achieve the complete integration of biomedical protocols, such as sample pre-processing and separation and analysis of biosamples on a chip. Electrowetting on dielectric (EWOD) as a distinctive digital microfluidic (DMF) is capable of manipulating droplets less than a microliter along the electrode arrays by applying AC voltages. EWOD chips, as microfluidic platforms, are inherently electrical and do not have to deal with problems …

A Two Stage Event Based Data Driven Controller For Improved Grasping Of An Artificial Hand, Christopher Abrego

Mechanical and Aerospace Engineering Dissertations - Archive

The human hand is one of the greatest (if not the greatest) tool known to mankind for grasping objects. So much so, that researchers have been investigating the development of artificial biomimetic hands in an effort to mimic their functionality and dexterity with the indent to apply the technology to various robotic platforms; ranging from end effectors for industrial pick-and-place robotics, to upper-limb prosthetics, to humanoids. There are certain features that make this endeavor challenging such as the mechanical design, actuation and sensorization, and functionality as well as the interaction from both the view point of interacting with an end …

Finite Element Analysis Of Composite Water Buffer Drum, Chinmay Shrikrishna S Godbole

Mechanical and Aerospace Engineering Theses - Archive

Composite materials offer many advantages for to many industries and developments based on their low density, corrosion resistance, and high strength to weight ratio. In addition, the use of composites allows for more design flexibility for products, the properties to meet specific design requirements, thus promoting better system oriented and cost-effective solutions. However, on a high performance equated basis, the economic incentive to use composite components can often be demonstrated based on their capability to reduce system and life cycle costs. Water buffer drum which is a pressure vessel holds a specified volume of fluid with desired temperature and pressure. …

On The Development And Integration Of Pneumatic Extrusion Module And A Methodology To Identify Process Parameters For Additive Manufacturing Using Machine Learning, Kashish Dhal

Mechanical and Aerospace Engineering Theses - Archive

Commonly used additive manufacturing platforms have a single extrusion module based on Fused Filament Fabrication (FFF) and their processing software generates G-Codes for this FFF module using defined process parameters. These platforms and software do not accommodate different processing modules such as viscous extruders or Direct Ink Writing (DIW). This research is focused on the development of a Pneumatic Extrusion Module (PEM) capable of dispensing viscous materials such as gels or slurries controlled through a digital pneumatic valve. A PEM is developed, integrated and its performance is evaluated on a multi-modality additive manufacturing platform in the MARS Lab. The operation …

Experimental Analysis Of A Single-Phase Direct Liquid Cooled Server Performance At Extremely Low Temperatures For Extended Time Periods, Gautam Gupta

Mechanical and Aerospace Engineering Theses - Archive

A data center is a centralized facility that we use for housing the computer systems and its related components such as high-end servers, redundant data connection and security controls. The next radical change in the thermal management of data centers is to shift from conventional cooling methods like air-cooling to direct liquid cooling (DLC) to deal with high thermal mass. The past few years have consistently seen wider adoption of direct liquid cooling because of its simplicity and high heat dissipation capacity. Passive single phase engineered fluid immersion cooling has several other benefits like better server performance, even temperature profile …

Quasi-One-Dimensional Scramjet Combustor Flow Solver Using The Numerical Propulsion System Simulation, Long Vu

Mechanical and Aerospace Engineering Theses - Archive

The flow field inside a scramjet engine combustor involves complex phenomena such as fuel-air mixing, combustion chemistry, and flow separation. In order to determine the properties of the flow along the length of the combustor, mass, momentum and energy balance equations are solved simultaneously using a numerical method. While a full three dimensional computational simulation gives detailed results with high order of accuracy, it demands a great amount of time and computational resource. A low order analysis produces a fast overall picture of the combustor operation which in turn provides valuable information suitable for the preliminary design process. This research …

Robot Motion Tracking Using Time-Of-Flight And Structured Light Sensors For Indoor Navigation, Karan Vishnu Rao

Mechanical and Aerospace Engineering Theses - Archive

Simultaneous localization and mapping for mobile robots has been an active research field for several years with focus on the problems of accuracy and dependability of the data from the robot's peripherals. The position estimates for mobile and industrial robots is usually achieved by using the information from the global positioning system in an outdoor environment and for indoor environment, technologies such as LiDAR sensors and Infrared (IR) camera based motion capture systems such as VICON (TM) are used. The main issue with these approach for indoor navigation is the monetary cost to associated with these technologies. The purpose of …

Comparison Of Carbon Steel And Composite Side Wall Of Light Rail Vehicle By Finite Element Analysis, Dilraj Singh

Mechanical and Aerospace Engineering Theses - Archive

A Railroad car is a vehicle used for carrying passengers and cargo. In the modern era, rail vehicles are designed as lightweight structures with the aim to minimize mass, operational energy demands, and CO2 emissions. Light rail vehicle is used at street level where they have direct contact with normal traffic and have a short distance between stations. In order to reduce dwell time at stops, and so, the vehicle can accelerate and deaccelerate easily, weight should be less and that is why low floor design is adopted these days. The sidewall is a crucial part of the car body …

Airflow Path And Flow Pattern Analysis Of Sub-Micron Particulate Contaminants In A Data Center With Hot Aisle Containment System Utilizing Direct Air Cooling, Satyam Saini

Mechanical and Aerospace Engineering Theses - Archive

The percentage of the energy used by data centers for cooling their equipment has been on the rise. With it has been the necessity for exploring new and more efficient methods, both from an engineering as well as business point of view, to contain this energy demand. The PCB boards are becoming more densely populated with multitude of smaller hardware on them, thereby, increasing its cooling requirements. Literature suggests that almost 40% of the total energy consumption in a typical Data Center is used for cooling purposes. Air cooling has always been the first choice for IT companies to cool …

Experimental Characterization Of Vertically Split Distribution Wet- Cooling Media Used In Direct Evaporative Cooling Of Data Center, Ahmed Al Khazraji

Mechanical and Aerospace Engineering Theses - Archive

When operating in direct evaporative cooling (DEC) mode, the amount of moisture added to a system can be controlled by frequently modulating water supply to the wet cooling media. Though many challenges arise due to geographical and site conditions, this concept can be applied to data centers to serve as a cost-effective alternative for maintaining the operating temperature of the facility at any weather condition. However, this method results in scale and mineral build up on the media because of an irregular water distribution. To prevent the scale formation, the operators allow the water supply continuously on the cooling media …

Investigation On Effective Modulus And Stress Concentration Factor Of 3d Reinforced Composite By Finite Element Analysis Method, Chandra Bhaskar Reddy Pittu

Mechanical and Aerospace Engineering Theses - Archive

Micromechanics of Composites aims to analyze the localized stresses inside any given constituents of the composite structure. This Thesis is focused on Calculating the effective modulus and the Stress concentration factor of the 3D straight Fiber Composite using Finite Element(FE). The compressive and a Shear response of a 3D Straight fiber composite comprising three directional E Glass Fibers reinforced in an epoxy matrix is analysed. This result is the 10% of overall Composite Ductility and a 10% of overall Shear displacement load in the orthogonal directions. FE calculations are reported to analyse the response of 3d reinforcement as of with …

Optimization Of Heating, Ventilation, And Air-Conditioning (Hvac) Chilled Water Plant Systems, Cliff Odhiambo Nudi

Mechanical and Aerospace Engineering Theses - Archive

Heating, Ventilation, and Air-conditioning accounts for about 60% of the total energy consumed in commercial facilities including office buildings, hospitals, retail stores, warehouses, campuses, manufacturing facilities, medical facilities, etc. As the cost of electricity and energy continue to rise, building owners and facility managers continue to witness a rise in the Total Cost of Ownership. Chilled water plant system is the largest consumer of energy in HVAC system consuming 75% of the total energy used in HVAC according to the Department of Energy. Operating chilled water plant systems at the recommended AHRI Standard 550/590 for performance rating of water chilling …

Design And Experimental Study Of Hydrostatic Thrust Air Foil Bearing, Myong Sok Song

Mechanical and Aerospace Engineering Theses - Archive

Oil-free bearing technology has several advantages over conventional oil-lubricated bearings. These advantages include high-speed operation, reduced weight, and increased reliability. Consequently, oil-free technology is expected to replace conventional bearings in a variety of applications. However, many challenges need to be addressed for widespread adoption of oil-free technology such as lower load capacity during start/stop and issues with controlling temperature. Thrust bearings, unlike their radial counterparts, are used for supporting axial loads and have become more important in recent years because of layout requirements other than double overhang configuration gaining consideration for specialized applications. Moreover, the requirements are demanding more extreme …

Simulation, Control And Testing Of A Custom 5-Dof Robotic Manipulator System, Roopak M. Karulkar

Mechanical and Aerospace Engineering Theses - Archive

Open chain manipulators are a well posed problem, however it was necessary to build a system customized to meet the needs of the Unmanned Ground Vehicle developed in the Aerospace Systems Laboratory. Considering that there are multiple such small ground vehicles, the main design constraint on the system was to be modular and lightwieght to enable quick swapping from both, a hardware and a software point of view. The purpose of this thesis is design, simulation and control a modular 5-Degree-of-Freedom manipulator with versatility in end effector configuration. This was achieved through the Robot Operating System which brings a high …

Experimental Investigation Of Thermophysical Properties Of Enhanced Nitrate Salt Nanofluids For Thermal Energy Storage (Tes) In Concentrated Solar Power (Csp) Systems, Vamsi Kiran Eruvaram

Mechanical and Aerospace Engineering Theses - Archive

The main source for energy production right now is from thermal, nuclear energy. But in the near future we might have crisis of coal so we need alternate renewable source for energy production the solution for that is sun, since solar energy is renewable and abundantly available. Concentrated solar power (CSP) technologies is one of the best solution to overcome this energy crisis, because it works from solar energy. If the CSP is incorporated with thermal energy storage (TES) we can produce energy even during night. TES with 15-hour storage capacity (Gemasolar) is already commercialized to operate a CSP plant …

Additive Manufacturing Process Investigation For The Fabrication Of Composite Scaffolds For Soft Tissue Application, Parimal Patel

Mechanical and Aerospace Engineering Theses - Archive

Additive manufacturing has been investigated and employed in the bio-medical domain for the fabrication of various devices and scaffolds. In various soft tissue engineering applications, multi-functional multi-material scaffolds are required for cell proliferation, structural integrity, bio-compatibility and tissue regeneration. In this research, an additive manufacturing methodology is developed to allow the fabrication of bio-composite scaffolds using a multi-modality in-house built platform. The researched materials for printing are Poly-L-Lactic Acid (PLLA) and a newly developed photo-curable radiopaque polymer called Rylar (Poly glycerole sebacate fumarate gadodiamide) mixed with a cross-linking agent Poly (Ethylene glycol) diacrylate (PEGDA). The developed methodology uses a Fused …