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Articles 2371 - 2400 of 2904

Full-Text Articles in Engineering

The Lattice Boltzmann Method For Computational Fluid Dynamics Applications, Chinmay Adhvaryu Aug 2008

The Lattice Boltzmann Method For Computational Fluid Dynamics Applications, Chinmay Adhvaryu

Mechanical and Aerospace Engineering Theses - Archive

An analysis of lattice Boltzmann method is presented in this thesis. This analysis contrast with the traditional lattice Boltzmann work, where complex fluids are considered with extended properties. Focus of the current thesis is on the validation and use of lattice Boltzmann method for traditional fluid dynamics. In first part of the document a historical and theoretical background of lattice Boltzmann method is presented. In this part some conclusions are drawn about the stability and other physical characteristics of the lattice Boltzmann method. Second part deals with the computer implementation of the LBM. It also discusses some aspect about practical …


The Development Of A Finite Element Tool For The Calculation Of Beam Cross Section Properties, Bryan Dale Mixon Aug 2008

The Development Of A Finite Element Tool For The Calculation Of Beam Cross Section Properties, Bryan Dale Mixon

Mechanical and Aerospace Engineering Theses - Archive

Cross section properties are crucial in the analysis and design of beams as they play a key role in the determination of the stress state encountered. The development of an FEM tool in MATLAB for the calculation of beam cross section properties will be discussed. Properties of interest include general cross section properties as well as the non-trivial warping-dependent properties for both the unrestrained and restrained cross section conditions for solid and hollow, open and closed sections.


Flip Chip Back End Design Parameters To Reduce Bump Electromigration, Vishal Nagaraj Aug 2008

Flip Chip Back End Design Parameters To Reduce Bump Electromigration, Vishal Nagaraj

Mechanical and Aerospace Engineering Theses - Archive

The advancement in flip chip technology has enabled us to meet the requirement of smaller die size along with the increased functionality. Due to this development in flip chip packaging technology along with higher current carrying requirement of solder bumps, electromigration has now become a reliability concern. In this research, a commercially available finite element tool is adopted in order to study the distribution of current density in eutectic solder bump for variety of back end design parameters. Geometries needed were generated by using Pro/Engineer® Wildfire 3.0 as a Computer-Aided-Design (CAD) tool and were transferred to ANSYS® 10.0, where meshed …


Development Of A Freeway Incident Rating System, Jose Javier Lopez Aug 2008

Development Of A Freeway Incident Rating System, Jose Javier Lopez

Civil Engineering Theses - Archive

A freeway incident rating system is proposed to classify incidents in terms of their disruptive potential to cause delays, fuel wastage, secondary accidents, and other adverse operational impacts. A two-dimensional rating scale is used which classifies incidents in terms of their severity and the number of agencies required to respond and clear incidents. Variables used in characterizing the severity include number of vehicles involved, number of lanes and shoulders blocked, time of incident occurrence, duration of incident until full clearance, and weather conditions at the time of the incident. The objective behind the development of such a rating system is …


Targeted Drug Delivery To Human Aortic Smooth Muscle Cells Using Biodegradable Nanoparticles, Danyel Specht Aug 2008

Targeted Drug Delivery To Human Aortic Smooth Muscle Cells Using Biodegradable Nanoparticles, Danyel Specht

Bioengineering Theses - Archive

Restenosis is a common problem that can occur in angioplasty patients. In order to reduce the restentosis rate, various treatments such as glucocorticoids and drug eluting stents have been used for angioplasty patients. However, their limitations include the inefficient delivery of drugs to inhibit smooth muscle cell proliferation, a major cause of restenosis. Therefore, we propose the use of biodegradable nanoparticles as a drug delivery system for transporting a therapeutic agent to human aortic smooth muscle cells (HASMC) to prevent their proliferation. In this study the glucocorticoid dexamethasone (DEX) was chosen as the therapeutic agent. A biodegradable polymer, poly (D,Llactide-co-glycolide) …


Subcellular Light Activation, Control And Manipulation Using A Dynamically Reconfigurable Nanopatterning System, Amruta Rajiv Joshi Aug 2008

Subcellular Light Activation, Control And Manipulation Using A Dynamically Reconfigurable Nanopatterning System, Amruta Rajiv Joshi

Bioengineering Theses - Archive

Cellular communication is the basis of all cellular activities and functions. Cell signaling is crucial in the processes of tissue maintenance, tissue development and homeostasis. Errors in transmission or interpretation of these signals can result in the onset of diseases like cancer. Efforts have been made to probe into the communication between cells, and the extracellular signals that cells transmit to each other. There is however, a necessity to understand cell communication within the cellular components themselves and to be able to perform a nanoscale analysis of the cell organelle behavior. Many cellular mechanisms involve processes at the subcellular level, …


Microfluidic Flow Cytometer For High Throughput Label Free Cell Analysis, Sajal Chirvi Aug 2008

Microfluidic Flow Cytometer For High Throughput Label Free Cell Analysis, Sajal Chirvi

Bioengineering Theses - Archive

Microfluidic flow cytometer for high throughput label free cell analysis is proposed. Detection of cell morphology plays an important role in determination of state of health and diagnosis of many diseases such as sickle cell anemia, cancer, urine analysis, blood analysis etc. The platform proposed integrates label free cell analysis, microfluidic platform and high throughput imaging. Label free analysis helps in analyzing cells without altering cell/protein of interest and also allows biophysical characterization of living cells. Microfluidic platform used is fabricated from soft lithography. It mimics biological environment due to its channel confinement and is biocompatible. Being optically clear (PDMS), …


Cytotoxicity Evaluation Of Temperature Sensitive Poly(N-Isopropylacrylamide) Nanoparticles For Drug Delivery, Aniket Sharadrao Wadajkar Aug 2008

Cytotoxicity Evaluation Of Temperature Sensitive Poly(N-Isopropylacrylamide) Nanoparticles For Drug Delivery, Aniket Sharadrao Wadajkar

Bioengineering Theses - Archive

The objective of this research project was to develop temperature sensitive poly(N-isopropylacrylamide) (PNIPA) nanoparticles for drug delivery applications. These nanoparticles were formulated by a radical polymerization method, and their toxicity was studied in vitro using MTS assays and various cell types such as fibroblasts, smooth muscle cells, and endothelial cells. Cytotoxicity results did not show a significant difference in cell survival when cells were exposed to different particle sizes (100, 300, and 500 nm). In addition, dose studies of 100 nm nanoparticles showed that the cells exposed to PNIPA nanoparticles at concentrations less than or equal to 5 mg/ml were …


Studies On Volume Change Movements In High Pi Clays For Better Design Of Low Volume Pavements, Thammanoon Manosuthikij Aug 2008

Studies On Volume Change Movements In High Pi Clays For Better Design Of Low Volume Pavements, Thammanoon Manosuthikij

Civil Engineering Dissertations - Archive

Numerous low- to medium-volume roads such as Farm Market (FM) roads constructed on expansive clay subgrades, especially in the eastern and central Texas, encounter severe pavement cracking and premature loss of serviceability. The maintenance costs, in some cases, are greater than the initial construction costs. The roads built on problematic expansive soils often become distressed due to volume changes associated with seasonal moisture content fluctuations. This dissertation research was attempted to evaluate models that predict volume changes movements of the expansive or highly plastic soils and also develop new models that could provide better prediction of volume change movements in …


Building Pressure Tests Of Fiber-Reinforced Foam-Based Lightweight Concrete Precast Wall Panels, Francheska Enid Seijo Aug 2008

Building Pressure Tests Of Fiber-Reinforced Foam-Based Lightweight Concrete Precast Wall Panels, Francheska Enid Seijo

Civil Engineering Theses - Archive

Instrumentation and procedures for building pressure tests were designed as a means of providing new wind pressure test methods for full-scale building models. Fiber-reinforced foam-based lightweight concrete precast wall panels were studied in this investigation. Three (3) full-scale prototype buildings were tested for this purpose. To determine the material properties and design parameters for this targeted 90 pcf (1,446 kg/m3) cellular lightweight concrete and to gain overall knowledge of its behavior, some tests such as compressive strength test, pull-out strength test, and flexural strength test were performed. The wind pressure tests performed provided results for strength, maximum wind pressure the …


Micromachined Nanoporous Membranes For Blood Oxygenation Systems, Vijayakrishnan Ambravaneswaran Aug 2008

Micromachined Nanoporous Membranes For Blood Oxygenation Systems, Vijayakrishnan Ambravaneswaran

Electrical Engineering Theses - Archive

An oxygenator is a medical device that aids in the exchange of oxygen and carbon dioxide in the human blood during procedures and illnesses that may cause the interruption or cessation of blood flow in the body. Porous membranes currently used in blood-oxygenation systems are bulky, and the pores are relatively large in dimension. The control over the pore size is poor due to the fabrication techniques used. The standard deviation of the pore size and the placement of the pores deteriorate even further with decreasing pore diameter. It is because of inaccurate pore placement and poor control over the …


Improved Design Of A Piecewise Linear Network, Sayantani Pal Aug 2008

Improved Design Of A Piecewise Linear Network, Sayantani Pal

Electrical Engineering Theses - Archive

An efficient design of the Piecewise Linear Network (PLN) which maps the N dimensional input vector space into an M dimensional output vector space is presented. Several clusters are formed in the given datasets and a linear mapping is fitted for each cluster using regression and the total mapping error is calculated. We have designed this network using Self Organizing Map (SOM) clustering which uses the Euclidean distance measure. Again the same has been designed by using various weighted distance measures whose results are compared. It is observed that there is a decrease in Mean Square Error (MSE) of the …


Study Of Patch Antennas For Strain Measurement, Uday Shankar Tata Aug 2008

Study Of Patch Antennas For Strain Measurement, Uday Shankar Tata

Electrical Engineering Theses - Archive

Reliable strain measurement is important for damage detection of mechanical and civil structures. Existing wireless strain sensing technologies require a high operating voltage, bulky signal conditioning systems, and an external wireless module to transmit the sensor output. These limitations make the strain monitoring unreliable and expensive. An innovative method of measuring strain using a patch antenna is investigated in this thesis to overcome the limitations of existing strain sensing technologies. The patch antenna is made of a thin sheet of low-loss insulating material, called the dielectric substrate. The antenna pattern, i.e. a metallic patch, is printed on one side of …


Error Correction Methods For Latency-Constrained Flash Memory Systems, Priyanka Ankolekar Aug 2008

Error Correction Methods For Latency-Constrained Flash Memory Systems, Priyanka Ankolekar

Electrical Engineering Theses - Archive

Maintaining the reliability of data stored in Flash devices and reading it correctly has become a challenge as the demand for higher density is forcing aggressive shrinking of Flash architectures. For all Flash systems, especially latency-constrained NOR Flash, an on-chip error correction code (ECC) is the only viable and robust solution to this problem. This thesis investigates and optimizes low-latency error correction schemes for on-chip implementation in NOR systems using existing error correction methods as a starting point. As the first step towards doing this, a mathematical relation has been derived to compute the bit error rate (BER) of a …


Automation Of Thermal Model Extraction And Optimization, Obiorah Oji Aug 2008

Automation Of Thermal Model Extraction And Optimization, Obiorah Oji

Electrical Engineering Theses - Archive

Semiconductor device model optimization is highly beneficial; it improves the accuracy with which we can predict the performance of real devices and whole circuits before they are fabricated. This helps save time and money in being able to predict undesirable circuit responses. Although, it proves to be very useful, it can become very time consuming. The goal of this thesis is to use readily available tools to enhance and automate the somewhat complex process of optimization and streamline it so that results can be analyzed quicker with the goal of generating VBIC models that accurately match the behavior of the …


Exploratory Study Of Gold Nanoshell As A Therapeutic Thermal Ablation Agent For Cancer Treatment Using Laboratory And Animal Tissue Phantoms, Yajuvendra Rathore Aug 2008

Exploratory Study Of Gold Nanoshell As A Therapeutic Thermal Ablation Agent For Cancer Treatment Using Laboratory And Animal Tissue Phantoms, Yajuvendra Rathore

Bioengineering Theses - Archive

Prostate cancer is the most common male cancer in the United States and the second leading cause of male death from cancer. Surgical removal of the prostate is associated with high risks of surgical complications and consequences such as incontinence and sexual dysfunction. In my study, I have investigated a nanoparticle-assisted photothermal therapeutic method that may be used for treatment of prostate cancer in the future. This method is minimally-invasive and uses gold nano-shells as hyperthermia agents to treat localized necrosis of cancer cells. I have conducted a feasibility study for a new class of NIR absorbing nanoparticles called Gold …


Study Of Normobaric Hyperoxia Effects During Focal Hypoxia-Ischemic Injury In Mice Using Optical Spectroscopy Measurements, Shereen Mohideen Aug 2008

Study Of Normobaric Hyperoxia Effects During Focal Hypoxia-Ischemic Injury In Mice Using Optical Spectroscopy Measurements, Shereen Mohideen

Bioengineering Theses - Archive

Optical spectroscopy has seen tremendous growth and development in recent years and has been extensively used to characterize the optical properties of biological tissues. The purpose of this study is to investigate the values of oxygen saturation and concentration of hemoglobin in mice with focal hypoxic ischemia after being recovered in normobaric hyperoxia. Mice at five different age levels were used for this purpose, in order to see the effects of hyperoxia at different developmental stages of the brain; ischemia was induced in them by ligating their right carotid artery and subjecting them to hypoxic (8% oxygen) environment for half …


Model Driven Analysis Of Optical Reflectance Spectroscopy For Detection Of Human Prostate And Kidney Cancers, Aditya Vivek Mathker Aug 2008

Model Driven Analysis Of Optical Reflectance Spectroscopy For Detection Of Human Prostate And Kidney Cancers, Aditya Vivek Mathker

Bioengineering Theses - Archive

Renal cell carcinoma is one of the most common forms of kidney cancer originating from the renal tubule. During surgery, it is difficult for the surgeons to identify the cancer tissue from the normal tissue and also the benign tumor from malignant tumor. Moreover, prostate cancer is the leading cause of death amongst men in the United States. In this study, optical reflectance spectroscopy with short source-detector separation is used as a minimally invasive technique to differentiate normal tissues from tumor lesions and also to differentiate benign from malignant tissues in renal cell carcinoma. Clinical post-operative readings were obtained using …


Comparison Of Hemodynamic Response Non-Linearity Using Simultaneous Functional Near Infrared Spectrsoscopy And Magnetic Resonance Imaging Modalities, Renuka Parlapalli Aug 2008

Comparison Of Hemodynamic Response Non-Linearity Using Simultaneous Functional Near Infrared Spectrsoscopy And Magnetic Resonance Imaging Modalities, Renuka Parlapalli

Bioengineering Theses - Archive

Blood oxygenation level dependent (BOLD) response, which is measured by functional magnetic resonance imaging (fMRI), is known to be a combination of various vascular parameters, among which deoxy-hemoglobin is argued to be a major contributor. Functional near infrared spectroscopy (fNIRS) though limited in its spatial resolution provides a promising tool to study cortical activations, due to its specificity of independent measurement of blood parameters (Oxy, De-oxy and Total Hemoglobin), high temporal resolution and ease of use. To integrate the best aspects of two imaging modalities, it becomes important to study the close relationship between the two imaging modalities. A finger …


Surgical Fluorescence Imager For Visualizing Anteriorly Placed Biliary Structures, In-Vivo During Human Cholecystectomy, Santosh Hariharan Aug 2008

Surgical Fluorescence Imager For Visualizing Anteriorly Placed Biliary Structures, In-Vivo During Human Cholecystectomy, Santosh Hariharan

Bioengineering Theses - Archive

Cholecystectomy is one of the most common procedures occurring in United States to cure gall bladder diseases. There are two means of performing this procedure, Open Cholecystectomy and Laparoscopic Cholecystectomy, the later one being more frequent. The critical issue while performing Cholecystectomy is injury to Common Bile Duct (CBD) which could cause post procedural complications. Since the CBD is under fat layer it is important to image and locate the CBD during the procedure. The novel fluorescence imager developed in this project would help visualize the CBD by using the fluorescence properties of Indocyanine Green, to be injected into the …


Study Of Nirs Based Motor Cortex Activation Patterns In Cerebral Palsy Affected Kids Using Image Based Metrics, Nayan Jaikrishna Asanani Aug 2008

Study Of Nirs Based Motor Cortex Activation Patterns In Cerebral Palsy Affected Kids Using Image Based Metrics, Nayan Jaikrishna Asanani

Bioengineering Theses - Archive

In recent years the National Institutes of Health has placed great emphasis on addressing the emergent need to accelerate translation of laboratory discoveries into clinical practice. The proposed study is very much aligned with this NIH emphasis, targeting on the translation of near infrared (NIR) brain imaging to clinical assessment for children with cerebral palsy. Over ten million Americans are affected by central nervous system disorders that result in motor deficits. Cerebral palsy (CP) is the most common motor disorder of central origin in childhood and affects at least 2 children per 1000 live births every year . One of …


Analysis And Design Of A Hypersonic Scramjet Engine With A Starting Mach Number Of 4.00, Kristen Nicole Roberts Aug 2008

Analysis And Design Of A Hypersonic Scramjet Engine With A Starting Mach Number Of 4.00, Kristen Nicole Roberts

Mechanical and Aerospace Engineering Theses - Archive

When pressures and temperatures become so high in supersonic flight that it is no longer efficient to slow the oncoming flow to subsonic speeds for combustion, a scramjet (supersonic combustion ramjet) is used in place of a ramjet. Currently, the transition to supersonic combustion generally occurs at a freestream Mach number around 5.0 to 6.0. This research details analysis completed towards extending scramjet operability to lower Mach numbers, while maintaining performance at higher Mach numbers within the same flowpath as detailed in the Air Force solicitation AF073-058. The specific goal is to determine whether the scramjet starting Mach number can …


Subsurface Investigations Using High Resolution Resistivity, Dharmateja Maganti Aug 2008

Subsurface Investigations Using High Resolution Resistivity, Dharmateja Maganti

Civil Engineering Theses - Archive

Electrical resistivity imaging has been proved to be well suited to produce images of subsurface conditionsbecause of the ability of the technique for detecting resistive features and discriminating subtle resistivity variations in the soil media. Electrical resistivity imaging survey was performed at E. Center Development in Duncanville, Texas. The survey was conducted using SuperSting R8/IP Multi-channel Resistivity Imaging System to image the subsurface structure. Both 2-D and 3-D electrical resistivity imaging tests were conducted using dipole-dipole array at 2 feet, 5 feet and 20 feet electrode spacing. Earth Imager 2D and Earth Imager 3D software's were then used to invert …


Sealing And Lamination Of Microfluidic Devices, Christopher Ryan Oliver Aug 2008

Sealing And Lamination Of Microfluidic Devices, Christopher Ryan Oliver

Industrial, Manufacturing, and Systems Theses - Archive

A difficult problem facing microfluidic manufacturing of devices remains that often material requirements force device designers to choose materials that are difficult to bond, seal or enclose. Examples of these materials include the Polyolefin family such as HDPE (High Density Polyethylene), PP (Polypropylene) or high performance polymers such as PEEK (Polyetheretherketone), Acetal or Polyimide. The problem arises from the chemical resistance of the materials making them ideal for processing corrosive chemicals but the same property reduces the effectiveness of laminates, surface bonding, surface coatings and solvents. To address this problem a methodology for sealing devices made of these materials is …


Design Of A Signal Generator Using Current Feedback Operational Amplifiers, Akm Sydul Haque Aug 2008

Design Of A Signal Generator Using Current Feedback Operational Amplifiers, Akm Sydul Haque

Electrical Engineering Dissertations - Archive

Sinusoidal, triangular and rectangular waveforms are generated using current feedback operational amplifiers. A signal generator using a Current Feedback Operational Amplifier (CFOA) was designed, simulated and fabricated. The simulated frequency of oscillation for the sinusoidal wave is 13.13 MHz to 23.94 MHz, for the triangular and the rectangular wave are 6.78 MHz to 59.5 MHz in simulation. The current feedback operational amplifier can achieve higher oscillation frequency than a voltage feedback operational amplifier. Two different types of current feedback operational amplifiers were designed. These are the double buffer current feedback operational amplifier and the double buffer current booster current feedback …


Sequential Frameworks For Statistics-Based Value Function Representation In Approximate Dynamic Programming, Huiyuan Fan Aug 2008

Sequential Frameworks For Statistics-Based Value Function Representation In Approximate Dynamic Programming, Huiyuan Fan

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Dynamic programming (DP) was derived by Bellman in 1957 as a mathematical programming method to solve multistage decision problems. The DP concept has great potential, but it only can solve small problems exactly under very limiting restrictions such as linear dynamics, quadratic cost, Gaussian random variable, etc. With advances in computational power, a new family of dynamic programming known as approximate dynamic programming (ADP) has emerged. A real-world DP problem is often high-dimensional and stochastic with continuous state variables. To handle this type of problem, ADP methods discretize/sample the continuous state space and approximate the future value (or cost-to-go) function …


Life Cycle Assessment Of Bio-Material Stabilized Expansive Soils, Ranjith Samuel Rosenberk Aug 2008

Life Cycle Assessment Of Bio-Material Stabilized Expansive Soils, Ranjith Samuel Rosenberk

Civil Engineering Dissertations - Archive

Pavement cracking is one of the major maintenance works that requires millions of dollars in repair costs annually. Pavement cracks are formed due to moisture and temperature fluctuations in the soil. Stabilization of pavement shoulder subsoil with the addition of compost material was studied for preventing pavement cracks. Eight different compost materials with three major feed stock sources such as biosolids, wood waste, and animal manure were investigated in this research. Compost treatment studies were performed at four different test sites located in various regions of the state of Texas. Laboratory experiments were conducted completed compost manufactured topsoil's (CMTs) to …


Effects Of Calcium-Based Treatment On Organic Soil Behavior, Srujan Rao Chikyala Aug 2008

Effects Of Calcium-Based Treatment On Organic Soil Behavior, Srujan Rao Chikyala

Civil Engineering Theses - Archive

Organic soils are found in many places around the world. Organic soils undergo large secondary settlements depending on the amount of organic matter present in the soil Organic soil is a mixture of finely divided particles of organic matter, in some instances visible fragments of partly decayed vegetable matter and shells are also present in the organic matter. In order to reduce the secondary settlements caused by organic matter, soil is treated with different stabilizing agents. The difficulties associated with organic soils arise when they are treated with cement or lime stabilizers, as organic matter inhibits cementitious reactions responsible for …


Influence Of Hypoxia, Hypercapnia And Inspiratory Efforts On Sympathoexcitation During Apnea, Vikram Rao Aug 2008

Influence Of Hypoxia, Hypercapnia And Inspiratory Efforts On Sympathoexcitation During Apnea, Vikram Rao

Bioengineering Theses - Archive

Obstructive Sleep Apnea (OSA) is characterized by frequent periods of apnea resulting in hypoxia, hypercapnia and fluctuations of intrathoracic pressure (inspiratory efforts). Hypoxia, hypercapnia and inspiratory efforts lead to stimulation of peripheral chemoreceptors, central chemoreceptors and baroreceptors, respectively, which in turn influence Muscle Sympathetic Nerve Activity (MSNA). We hypothesized that hypoxia and hypercapnia result in an elevated MSNA response, while inspiratory efforts result in a reduced MSNA response during apnea. To test the hypothesis, we determined the contributions of hypoxia (at 12% O2), hypercapnia (at 3% CO2) and inspiratory efforts (mueller maneuvers at 20 mmHg) to MSNA (using microneurographic techniques) …


A Novel Approach For Mri Image Classification And Image Retrieval, Ankit Vinod Master Aug 2008

A Novel Approach For Mri Image Classification And Image Retrieval, Ankit Vinod Master

Bioengineering Theses - Archive

OBJECTIVE: Classification of MRI image data based on its attribute characteristics is very important for storing the image data and its efficient retrieval. This project aims to find a solution to the problem of classification of the images that are stored on a hard drive and image retrieval from the image database with optimum automation in a user friendly way. METHOD: Matlab was used to create a software tool for image classification and, Java and SQL were used to create a software tool for image retrieval. RESULTS: Image classification tool could read multiple files, extract attribute values from the files …