Engineering Commons^™

The Design And Linearization Of Flow Control Device And Pressure Forces On Valve, Penchala Sumanth Reddy Challa

Mechanical and Aerospace Engineering Theses - Archive

Emerging technologies are pushing the limits by reducing the size of the nodes, raising the heat densities of packages thereby demanding better thermal management. The cooling power requirement increases drastically when air is used as the cooling medium in high power density servers as air has a low heat transfer coefficient. Very viable replacements for air as the cooling medium are water and oil. Oil is not as widely used as it has its own disadvantages when compared to water. Water has appreciably higher heat transfer coefficient, which helps it to remove heat from the server at a much faster …

Computational Model For Steady State Simulation Of A Solid Oxide Fuel Cell (Sofc) Planar Stack Model Undergoing Reforming Process, Vaibhav Vijay Indulkar

Mechanical and Aerospace Engineering Theses - Archive

Solid Oxide Fuel Cell (SOFC), is a clean and low-pollution technology of generating power of high efficiency. Its applicability for both stationery and transportation power generation systems, adaptability for wide range fuel sources, as wells its process of direct conversion of fuel to energy make it an important source of power generation. An effective design of sub-systems or individual components play a key role in overall working of a plant. Thus, critical analysis at the component level is of importance for the overall plant efficiency. In the present study a heat transfer model of a planar SOFC stack to be …

Reliability Assessment Of Solder Joint Using Bga Package – Megtron 6 Versus Fr4 Printed Circuit Boards Using Drop Testing, Pradnya Chandrakant Mundhe

Mechanical and Aerospace Engineering Theses - Archive

In electronic industry Ball grid array (BGA) package, surface mount technology has been used widely, due to its robust design, high density connections and improved performance. In surface mount technology, solder joints are used to interconnect package and PCB board assembly. High frequency laminates use in PCB boards provides excellent performance for high speed, frequency devices. Nelco 4000-13EPSI, Panasonic Megtron 6, and Rogers 4350B are few popular laminates. Component size reduction and structural complexity because of increasing number of transistors are making it very difficult to protect the packages from mechanical, thermal, and electrical damage. Difference in material properties between …

Computational Morphology Modelling And Mixed Mode Fracture Analysis Of Zrb2/Sic Based Ceramic Nano-Materials Using Molecular Dynamics, Krutarth Shaileshkumar Patel

Mechanical and Aerospace Engineering Theses - Archive

Transition metal carbides, nitrides, and borides are a group of Ultra High-Temperature Ceramic (UHTC). Owing to their remarkable properties of the high melting point, high thermal conductivity and excellent strength at elevated temperature ZrB2 based composites are of high interest for use in the high-temperature environment. It is proved that addition of SiC in ZrB2 can advance composite’s oxidation resistance, mechanical strength, fracture toughness and sintering behavior. Firstly, molecular dynamics is used to simulate crack growth under mixed mode loading in Al, SiC, and ZrB2 single crystals by considering inclined crack under uniaxial tension and crack growth angle are compared …

Investigation Of Thermophysical Properties Of Enhanced Molten Salt Nanofluids For Thermal Energy Storage (Tes) In Concentrated Solar Power (Csp) Systems, Joohyun Seo

Material Science and Engineering Dissertations - Archive

Concentrated solar power (CSP) technologies have a great economical and technical potential for energy production in future. Its incorporation with thermal energy storage (TES) overcomes one of the biggest challenges in most renewable energy technologies, the intermittency of energy supply by natural resources. TES with 15-hour storage capacity is already commercialized to operate a CSP plant for 24 hours a day. When the sunlight is concentrated by mirrors into a small focal point, a heat transfer fluid (HTF) transfers the collected heat to a turbine or an engine to produce electricity and any surplus heat to a TES unit for …

Shear Behavior Of Synthetic Fiber Reinforced Concrete Box Culverts, Mahnaz Mostafazadeh

Civil Engineering Dissertations - Archive

This research pursues a comprehensive experimental study on the shear capacity of zero-slump, dry-cast Synthetic Fiber-Reinforced Concrete (SYN-FRC) with the aim of reducing or even eliminating stirrups in box culverts. Since using stirrups in structures such as box culverts need labor work and cause reinforcement congestion, eliminating or reducing stirrups in design, prevent poor-quality concrete, help better concrete compaction and could save manufacturer time and money over the years. This study first determined the shear capacity of synthetic fiber concrete matrix by varying fiber volume fraction. Then, FEA and full experimental tests have been conducted to evaluate the effect of …

Revealing Hemodynamic Response And Dynamic Changes In Functional Cortical Networks Using Functional Near-Infrared Spectroscopy (Fnirs), Jianwei Cao

Bioengineering Dissertations - Archive

Therapeutic interventions, such as physical therapy and non-invasive brain electrical stimulation can enhance the physical performance of persons with brain disorders. One often-used form of physical therapy named constraint-induced movement therapy (CIMT) improves motor control skills of children with cerebral palsy (CP) through forced intensive use of the affected extremity. A complementary method to physical rehabilitation methods for overcoming a deficit is to facilitate use of the affected brain areas by non-invasive brain electrical stimulation. One currently popular form of brain stimulation is transcranial direct current stimulation (tDCS), which has been shown to enhance both motor and language performance in …

Plasma Enhanced Chemical Vapor Deposition Coating Amorphous Silica Based Implants Enhancing Angiogenesis And Mitigating Toxic Oxidative Stress In Critical Size Bone Defects, Felipe Alves Monte

Bioengineering Dissertations - Archive

The advances in bone tissue engineering search for a biomaterial that could efficiently and gradually replace the bone while the new tissue grows through the implanted structure. However, due to limitations mainly related to mechanical properties and challenges, such as the balance between tissue regeneration and material degradation, the coating of well-known inert materials still has been used in orthopedics and dental clinical practices. Bone defects are commonly related to deleterious oxidative stress induced by low oxygen levels and inflammation. Toxic oxidative stress can impair damaged tissue healing due to inhibiting new blood vessels and new bone formation. The interaction …

Improvements To The Duplicate Shear Tester, Yazeed Suleiman Jweihan

Civil Engineering Theses - Archive

Rutting in the asphalt concrete layer is a major distress in flexible pavements caused by the permanent shear deformation in asphalt mixes. The shear deformation is induced by heavy truck axis during hot summer days. Rutting affects directly the safety and users comfort. Therefore, developing of an appropriate test device for measuring the fundamental shear properties of asphalt mixes is important in order to improve the rutting resistance of asphalt mixes and pavement performance. The desired device should be simple, inexpensive, and accurate to be able to be incorporated for a quality control or quality assurance process, as well as …

Evaluation Of Plant Root On The Performance Of Evapotranspiration (Et) Cover System, Md Jobair Bin Alam

Civil Engineering Dissertations - Archive

The performance of an evapotranspiration (ET) cover for a landfill exceeds that of a conventional landfill final cover. Its low percolation and high evapotranspiration rely on the properties of unsaturated soils, the energy demands of plants, and the atmosphere. Plant roots pull water out of the cover soil and release it into the environment, thus managing water in a much more natural way than the conventional cover, where water is controlled by creating a physical barrier. Therefore, plant roots are a significant component in the optimization of ET cover performance. In recent years, a great deal of effort has been …

Quantitative Non-Destructive Evaluation (Nde) Of Frp Laminate-Concrete Bond Strength, Mina Riad

Civil Engineering Dissertations - Archive

Repair and rehabilitation methods for civil infrastructure have become a topic of great interest to engineers. Fiber Reinforced Polymer (FRP) is considered as one of the most popular and practical solutions for strengthening and retrofitting of civil infrastructure. Several past studies indicated that significant increase in strength and stiffness can be achieved by using this technology. The FRP-concrete interface bond is critical in transferring stresses from the concrete surface to the FRP. However, the evaluation of the bond strength is still a challenging issue. To evaluate the bond strength using non-destructive techniques, 32 concrete beams strengthened with FRP using different …

Non-Linear Analysis Of Steel Fiber Reinforced Concrete Hollow Columns Under Uniaxial Bending, Mohammed Huzaifa Ghori

Civil Engineering Theses - Archive

This study investigates the performance of Steel Fiber Reinforced concrete hollow columns under axial compressive load and uniaxial bending with varying amounts of steel fiber using Finite Element Method of Analysis. The columns are of two groups, one with a 10% void and the other group has 20% void at the center. Each group’s specimens’ fiber content is varied in 0.5% increments from 0 to 1.5%. Also, the collapse load of the columns was obtained. Numerical results were compared with the available experiments. Two parametric studies were conducted by varying the amount of void percentages and steel fiber contents. In …

Comparing Methods Of Targeting Obesity Interventions In Populations: An Agent-Based Simulation, Rahmatollah Beheshti, Mehdi Jalalpour, Thomas A. Glass

Civil and Environmental Engineering Faculty Publications

Social networks as well as neighborhood environments have been shown to effect obesity-related behaviors including energy intake and physical activity. Accordingly, harnessing social networks to improve targeting of obesity interventions may be promising to the extent this leads to social multiplier effects and wider diffusion of intervention impact on populations. However, the literature evaluating network-based interventions has been inconsistent. Computational methods like agent-based models (ABM) provide researchers with tools to experiment in a simulated environment. We develop an ABM to compare conventional targeting methods (random selection, based on individual obesity risk, and vulnerable areas) with network-based targeting methods. We adapt …

Systematic Review For Water Network Failure Models And Cases, Yufei Gao

Graduate Theses and Dissertations

As estimated in the American Society of Civil Engineers 2017 report, in the United States, there are approximately 240,000 water main pipe breaks each year. To help estimate pipe breaks and maintenance frequency, a number of physically-based and statistically-based water main failure prediction models have been developed in the last 30 years. Precious review papers focused more on the evolution of failure models rather than modeling results. However, the modeling results of different models applied in case studies are worth reviewing as well.

In this review, we focus on research papers after Year 2008 and collect latest cases without repetition. …

Three-Dimensional Vapor Intrusion Modeling Approach That Combines Wind And Stack Effects On Indoor, Atmospheric, And Subsurface Domains, Elham Shirazi, Kelly G. Pennell

Civil Engineering Faculty Publications

Vapor intrusion (IV) exposure risks are difficult to characterize due to the role of atmospheric, building and subsurface processes. This study presents a three-dimensional VI model that extends the common subsurface fate and transport equations to incorporate wind and stack effects on indoor air pressure, building air exchange rate (AER) and indoor contaminant concentration to improve VI exposure risk estimates. The model incorporates three modeling programs: (1) COMSOL Multiphysics to model subsurface fate and transport processes, (2) CFD0 to model atmospheric air flow around the building, and (3) CONTAM to model indoor air quality. The combined VI model predicts AER …

Evolution Characteristics Of Perovskite Solar Cells In Air And Vacuum Environments, Xiaohui Wang, Hojjatollah Sarvari, Hongmei Dang, Zhi Chen, Vijay P. Singh

Electrical and Computer Engineering Faculty Publications

Solid state hybrid organometal halide perovskite solar cells have become the research hotspots recently. We prepared perovskite solar cells by the simple two-step method in the ambient condition. The solar cell samples were kept in air and vacuum environments, respectively. J_sc shows good stability in vacuum for up to 27 days, while it drops a lot in air. There is a remarkable promotion of FF for the air-stored samples compared that of the vacuum-stored samples. Changes in V_oc of vacuum-stored and airstored samples exhibited a similar behavior, both showing a slight increase. We believe the moisture in air …

Video Frame Interpolation Via Adaptive Separable Convolution, Simon Niklaus, Long Mai, Feng Liu

Computer Science Faculty Publications and Presentations

Standard video frame interpolation methods first estimate optical flow between input frames and then synthesize an intermediate frame guided by motion. Recent approaches merge these two steps into a single convolution process by convolving input frames with spatially adaptive kernels that account for motion and re-sampling simultaneously. These methods require large kernels to handle large motion, which limits the number of pixels whose kernels can be estimated at once due to the large memory demand. To address this problem, this paper formulates frame interpolation as local separable convolution over input frames using pairs of 1D kernels. Compared to regular 2D …

Streaming Mysql Database Activity To Aws Kinesis, Chris I. Voncina

Computer Engineering

Connecting Amazon RDS MySQL engine with AWS Kinesis is a feature that RDS customers have often requested. A good example indicating customer demand is demonstrated on AWS’ forum post at https://forums.aws.amazon.com/thread.jspa?messageID=697516.

Upon completion, my project will enable Amazon RDS to pick up the MySQL open source project, integrate the MySQL plugin with Amazon RDS MySQL and deliver this feature to Amazon RDS MySQL customers. Other open source engine projects can follow and build upon my project.

Amazon Aurora delivered similar capability to the project. See details at https://aws.amazon.com/about-aws/whats-new/2016/10/amazon-aurora-new-features-aws-lambda-integration-and-data-load-from-amazon-s3-to-aurora-tables/

Effects Of Edible Coating On The Sensory And Physiochemical Properties Of Roasted Coffee Beans Stored At Ambient Temperature, Tuan Quoc Le

Manipal Journal of Science and Technology

Roasted coffee beans during industrialized processing are difficult to retain volatile compounds and flavour. Several methods, especially edible coating have been studied and used widely in the world, while applications for Vietnamese coffee beans are still limited. In this study, the effects of edible coating with xanthan gum at different concentrations, 0.5%, 1%, and 1.5% (w/v) on sensory and physiochemical properties of two major types of coffee, Robusta and Arabica were investigated. The results presented the positive effects on the sensory and physiochemical properties of both two types of coffee during 30-day-storage at ambient temperature. The hardness, pH value, moisture …

Impact Assessment Of Sewage Sludge To Ecological Environment, Thanh Tran

Manipal Journal of Science and Technology

Sewage sludge from wastewater treatment plants in Vietnam is facing a difficulty due to the significant increase of the volume of discharge to landfill and its impacts on environment. There have been many articles about the odour impact on people living around Binh Hung wastewater treatment plant; however, there is no clear research on the impact, when sewage sludge is discharged directly into the environment. This study was implemented with the change of sludge concentration and environmental conditions to assess the impact of mud through analytical ability to germinate and grow height of cucumber. Results showed that the ratio of …

Effect Of Stress Concentration Factor On Threaded Hole Under Different Loading Conditions Using Transfer Functions, Sharnappa Joladarashi

Manipal Journal of Science and Technology

Bolted joint is most widely used in assembling parts and joining various sections. In simulations, which include large models like jet engines, gas turbines, aviation structures, etc., where bolted joints are used in large numbers, modelling the threads for bolts and holes is computational expensive. To reduce the associated complexities of modelling actual threads, alternative models of representation are used. A bolted joint is influenced by different combinations of forces depending on the model and its function. Stress concentration factor of threaded hole for various load cases using static structural analysis in ANSYS is studied. Simplified modelling techniques are simulated …

Eigen-Based Offline Handwritten Digit Recognition Using Multi-Layer Perceptron, Muralikrishna S N

Manipal Journal of Science and Technology

Offline handwritten digit recognition is one of the important tasks in pattern recognition, which is being addressed for several decades. The application of digit recognition lies majorly in areas like postal mail sorting, bank check processing, form data entry, etc. In recent years, research in this area focusses on improving the accuracy and speed of the recognition systems. Many algorithms have been proposed that achieve high recognition rates. In this paper, we propose a highly accurate and fast method using an artificial neural network. Also, we bring out a comparative study of Kirsch directional feature versus the Eigen-based method using …

Evaluation Of Opportunities And Challenges Of Using Inrix Data For Real-Time Performance Monitoring And Historical Trend Assessment, Anuj Sharma, Vesal Ahsani, Sandeep Rawat

Nebraska Department of Transportation: Research Reports

In recent years there has been a growing desire for the use of probe vehicle technology for congestion detection and general infrastructure performance assessment. Unlike costly traditional data collection by loop detectors, wide-area detection using probe-sourced traffic data is significantly different in terms of measurement technique, pricing, coverage, etc. This affects how the new technology is applied and used to solve current traffic problems such as traffic incident management and roadway performance assessment. This report summarizes the experiences and lessons learned while using probe data for traffic operations and safety management in the state of Nebraska and makes recommendations for …

Experimental Study On Resilient Behavior Of Geocell-Reinforced Recycled Asphalt Pavement Base Layer: Model Development, Manikanta Saladhi

Civil Engineering Theses - Archive

Recycled Asphalt Material (RAP) is defined as removed and reprocessed pavement materials containing asphalt and aggregates. These materials are obtained when asphalt pavements are removed for the rehabilitation and maintenance of distressed pavements. The use of RAP as a base/subbase aggregate in pavement construction is technically and environmentally a sustainable solution, and conserve use of natural resources by requiring less virgin aggregate in pavement construction. Past studies showed that the use of 100% RAP as base course lacks shear strength and can undergo large deformations. Geocells are a system of three-dimensional, interconnected, honeycombed cellular structures that resist the lateral expansion …

A Thermal Inertia Approach To Precision Irrigation Using Unmanned Aerial Vehicles Coupled With High-Resolution Multispectral Imagery, Kevin James Wienhold

Civil Engineering Theses - Archive

Soil moisture is a critical variable in the optimization of irrigation scheduling in water resources management. Despite using tens to hundreds of thousands of gallons of water each day, many golf courses rely on a sparse network of point measurements to estimate irrigation requirements for turfgrass management. This study describes a novel system known as Precision Irrigation Soil Moisture Mapper (PrISMM) in which an unmanned aerial vehicle equipped with multispectral sensors is used to estimate volumetric water content (VWC) at a golf course using a thermal inertia approach. PrISMM consists of three central components, including (1) high-resolution thermal and optical …

Performance Of Light-Frame Wooden Structure (Lfws) Subjected To Combined Wind And Flood Hazards, Ajay Baniya

Civil Engineering Theses - Archive

Light Frame Wooden Structures (LFWS), which are more prone to wind damage by virtue of their light weight, sustain severe damage when they are subjected to simultaneous flood and wind. A difficulty in Multi-hazard design for wind and flood is that the load and resistance factor make use of different design philosophies developed by different sub-disciplines. After Multi-hazard events, in most cases, it is complicated to determine the sole damage done by flood or wind alone. The load path of Wooden structure is already ambiguous, the addition of flood characteristics makes the analysis and design process more complicated. It has …

A Study On The Turbulence Characteristics And Mixing Performance Of Streamwise Vortex Interactions In Supersonic Flow, Cody R. Ground

Mechanical and Aerospace Engineering Dissertations - Archive

The scramjet engine offers the unique capability to enable sustained airbreathing flight at hypersonic speeds. However, in order to reach its full application potential, further technological maturation of several system level components is necessary. One such component is the fuel injection system. The flow conditions characteristic of the scramjet combustor are such that the rate-limiting step in the fuel injection/mixing/combustion process is the mixing of the fuel and air. For this reason, the fuel injection system must be designed with the goal of enhancing the rate of fuel/air mixing. One method that has shown potential to enhance fuel/air mixing in …

Development Of A Framework And Analysis System To Support Intervention In Newborn Healthcare, Holly E. Lane

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

One of the most vulnerable populations in healthcare is the newborn infant. As hospitalization for childbirth is the largest cause for entry into a healthcare facility, the population of newborns each year is extensive as is their cost of care. Newborn infants also may have additional costs associated with readmission for common or preventable illnesses, which may occur due to insufficient infant screening or lack of caregiver knowledge. Much research has been done to attempt to determine causes of readmission, what contributes to an increased or decreased readmission rate among newborns, and how healthcare interventions can impact these rates and …

Investigation On Metal-Composite Hybrid Flywheels Using Finite Element Method, Ching Huai Wang

Mechanical and Aerospace Engineering Theses - Archive

This research is aimed to investigate the kinetic energy storage of a hybrid metal-composite flywheel rotating at high speeds. The upper limit of energy, which flywheel can supply, is restricted by the strength of material because both energy and stress are proportional to the density of the material and the square of the velocity. Metal flywheels operate at lower rotational speed and supply less energy than the composite flywheels. Composite flywheels have a very high density per unit mass, but lower energy density per unit of the design volume. The ultra-high speed of composite flywheels creates some engineering challenges such …

Reliability Assessment Of Solder Joint Interconnects Of Bga Package-Megtron Series Under Power Cycling, Mahesh Pallapothu

Mechanical and Aerospace Engineering Theses - Archive

Solder joint interconnects are the second level assembly in surface mount interconnection technology. Mismatch in the coefficient of thermal expansion (CTE) between package and substrate or PCB creates failure in solder joints such as excessive warpage, low-k dielectric cracking, solder mask cracking and bump cracking. Conventional accelerated thermal cycling tests are performed to evaluate the Solder Joint Reliability (SJR). But, in everyday application, the package is subjected to Power cycling. Power cycling is the phenomenon where the package experiences non-uniform temperature distribution in the package with the chip as an internal heat generating source when an electronic device is turned …