Engineering Commons^™

Wind Turbine Level Energy Storage For Low Voltage Ride Through (Lvrt) Support, Ali Yousef

Theses and Dissertations

Renewable energy is a green source of energy that is clean, available and sustainable. Wind energy generation has been experiencing the largest growth among renewable sources due to lower cost and advanced technologies. Wind energy power plants or farms need low maintenance and last for a long time. The increasing higher penetration of wind energy in the grid has transformed wind energy into major player in grid operation and economics. Wind energy systems now have to participate in grid support and provide ancillary services.

Variable wind speed leads to variable wind power generation, voltage fluctuations, and frequency deviations, which are …

Effects Of Phosphate On The Transport Of Escherichia Coli In Saturated Quartz Sand, Nan Chen

Theses and Dissertations

Bacterial deposition and survival in porous media is a crucial phenomenon in various environmental processes including bioremediation, water treatment, and pathogen contamination. The fate of bacteria in porous media may be greatly influenced by ionic strength and phosphate. Although phosphate is widespread in the natural environment, the influence of phosphate on the transport of three strains of ESCHERICHIA COLI O157:H7 cells in the groundwater system remains unknown.

Experiments were performed in saturated sand packed columns with and without phosphate to examine the transport of bacteria, deposition rate coefficient, interaction energy between bacteria and sand, and bacteria surface charge.

Experimental results …

Container Handling Algorithms And Outbound Heavy Truck Movement Modeling For Seaport Container Transshipment Terminals, Mazen I. Hussein

Theses and Dissertations

This research is divided into four main parts. The first part considers the basic block relocation problem (BRP) in which a set of shipping containers is retrieved using the minimum number of moves by a single gantry crane that handles cargo in the storage area in a container terminal. For this purpose a new algorithm called the look ahead algorithm has been created and tested. The look ahead algorithm is applicable under limited and unlimited stacking height conditions. The look ahead algorithm is compared to the existing algorithms in the literature. The experimental results show that the look ahead algorithm …

Numerical Analysis Of Die-Casting Process In Thin Cavities Using Lubrication Approximation, Alexandre Reikher

Theses and Dissertations

Casting of thin wall parts has become a reality of the die cast industry today. Computational fluid dynamics analyses are an integral part of the production development process. Typically the three-dimensional Navier-Stokes equations coupled with the energy equation have to be solved in order to gain an understanding of the flow and solidification patterns, position of the flow front, as well as location of the solid-liquid interface as a function of time during the process of cavity filling and solidification. A typical solution of the governing equations for a thin-wall casting requires large number of computational cells, and as a …

Discovery And Correction Of Bias In Precision Landmark Location, Colin Foster

Theses and Dissertations

Precision Landmark Location (PLL) estimation is an integral part of 3D motion tracking. Circular landmark location estimation is one method of PLL. Current methods of estimation lead to systematic errors with a magnitude of up to .02 pixels. Estimation inaccuracies of this magnitude lead to unacceptable errors in depth measurement, the largest source of error. In the scope of this thesis, inadequacies in circular landmark location are uncovered and techniques to correct these errors are analyzed, tested, and demonstrated. Deviations in simulated images are seen to be reduced by a factor of three and the variances of real-world data were …

Smart Carbon Nanotube/Fiber And Pva Fiber-Reinforced Composites For Stress Sensing And Chloride Ion Detection, Joshua A. Hoheneder

Theses and Dissertations

Fiber reinforced composites (FRC) with polyvinyl alcohol (PVA) fibers and carbon nanofibers (CNF) had an excellent flexural strength in excess of 18.5 MPa compared to reference samples of 15.8 MPa. It was found that the developed, depending on applied stress and exposure to chloride solutions, composites exhibit some electrical conductivity, from 4.20x10^-4 (ohm*m)^-1 to. 4.13x10^-4 (ohm*m)^-1. These dependences can be characterized by piezioresistive and chemoresistive coefficients demonstrating that the material possesses self-sensing capabilities. The sensitivity to stain and chloride solutions can be enhanced by incorporating small amounts of carbon nanofibers (CNF) or carbon nanotube (CNT) into composite structure. Conducted research …

Optical Cryoimaging Of Celular Redox In Kidneys From Diabetic Mice, Sepideh Maleki

Theses and Dissertations

Diabetic Nephropathy (DN) is the major single cause of end stage renal diseases (ESRD) in the United States. Diabetes is the third leading fatal disorder after cancer and heart disease. It is affecting 8.3% of the residents of the United States, with a total healthcare cost of $174 billion/yr by 2010.

There currently exists a need for a sensitive and specific diagnosis for temporal detection of oxidative stress (OS) in cellular metabolic levels, which plays an early role in the development of DN. The objective of this research is to use a fluorescence optical imaging technique in order to delineate …

Effect Of Mechanical Abrasion On Oil/Water Contact Angle In Metals, Simin Salam Tabrizi

Theses and Dissertations

In this study the oil/water angle for brass, aluminum, hastelloy and 316 stainless steel was experimentally studied as a function of surface roughness. Samples were mechanically abraded by sandpaper in the way that all the scratches were parallel. Surface roughness was measured by profilometer, Nano-Indenter, and Atomic Force Microscope (AFM). The relationship between sandpaper particle size and surface roughness for all four metals was established. The highest surface roughness obtained for steel 316 ground by 180 grit sandpaper (1.23µm) and the smoothest surfaces were achieved for brass and aluminum after grinding with alumina (0.03 µm).Then oil/water contact angles were measured …

Stormwater Quality Characterization, Modeling, And Management For The Greater Milwaukee Area, Wisconsin, Puripus Soonthornnonda

Theses and Dissertations

Storm sewer pipes in the Greater Milwaukee area collect poluted stormwater runoff