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Application Of Pd-Catalyzed Reactions In The Total Synthesis Of Oroidin-Derived Alkaloids, Manojkumar R. Bhandari Jan 2010

Application Of Pd-Catalyzed Reactions In The Total Synthesis Of Oroidin-Derived Alkaloids, Manojkumar R. Bhandari

Chemistry & Biochemistry Dissertations - Archive

The oroidin family of marine natural products is a growing group of sponge-derived alkaloids which contain 2-aminoimidazole and pyrrolecarboxamide fragments as their signature features. Due to their structural diversity and biological activity, many groups are interested in the total synthesis of these natural products. It has been proposed that many of the alkaloids in this family are produced in nature simply by dimerization and/or cyclization of the simplest member, oroidin. In this dissertation we have attempted to explore these biosynthetic relationships to complete the total synthesis of several oridin-derived natural products. This dissertation consists of two parts. The first part …

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Analytical Characterization Of Anthocyanins From Natural Products By Reverse-Phase Liquid Chromatography-Photodiode Array-Electrospray Ionization-Ion Trap-Time Of Flight Mass Spectrometry, Jeremy S. Barnes Jan 2010

Analytical Characterization Of Anthocyanins From Natural Products By Reverse-Phase Liquid Chromatography-Photodiode Array-Electrospray Ionization-Ion Trap-Time Of Flight Mass Spectrometry, Jeremy S. Barnes

Chemistry & Biochemistry Theses - Archive

Anthocyanins are known to be one of the most powerful phytochemical antioxidant and believed to have a positive influence on a variety of health conditions. Numerous studies continue on these compounds that are readily found in most plants. Red hybrid-tea rose petals and wild blueberries were used as model systems for optimizing the extraction and identification process of anthocyanins in plant material using high performance liquid chromatography (HPLC) and mass spectrometry (MS) without the use of authentic standards. A number of extraction parameters, including sample homogenization, solvent selection and acid type and amount, were varied to examine the effects on …

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Trace Element Geochemistry In Groundwater Flow Systems, Stephanie Scholten Willis Jan 2010

Trace Element Geochemistry In Groundwater Flow Systems, Stephanie Scholten Willis

Earth & Environmental Sciences Dissertations - Archive

This research focuses on trace element geochemistry in three groundwater flow systems: the Carrizo Sand, the Upper Floridan, and the Aquia aquifers. The focus is threefold: (i) studying the geochemical behavior, concentrations, and fractionation patterns of rare earth elements (REEs) along two flow paths by examination of both groundwater and sediment samples, (ii) investigating the behavior of arsenic (As) and antimony (Sb) and comparing these data to reveal the biogeochemical processes affecting As and Sb concentrations and speciation as well as determining correlations between As and Sb concentrations, and (iii) formulating adsorption isotherms to demonstrate the adsorption capacity of As …

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Verrucomicrobia: A Model Phylum To Study The Effects Of Deforestation On Microbial Diversity In Amazon Forest, Kshitij Ranjan Jan 2010

Verrucomicrobia: A Model Phylum To Study The Effects Of Deforestation On Microbial Diversity In Amazon Forest, Kshitij Ranjan

Earth & Environmental Sciences Theses - Archive

The Amazon rainforest is known for having a very high diversity of plants and animals. However, it is one of the least understood ecosystems regarding microbial diversity. Microorganisms are important for the ecological balance of any ecosystem and play important role in various biogeochemical cycles. As the Amazon rainforest undergoes to rapid deforestation, loss of its biodiversity is expected. This research aims to determine the effects of deforestation on the soil microbial diversity of the Amazon forest. Toward this, we selected the phylum Verrucomicrobia as a model for observing changes in the microbial structure of rainforest soils. Samples were collected …

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Growth And Toxicity Of Prymnesium Parvum In Long-Term Cultures At Low Temperature And Salinity, Xianzi He Jan 2010

Growth And Toxicity Of Prymnesium Parvum In Long-Term Cultures At Low Temperature And Salinity, Xianzi He

Earth & Environmental Sciences Theses - Archive

There is a paradox reported concerning observations of toxic blooms of Prymnesium parvum in winter in Texas (USA), and its growth performance in the laboratlry. Culture experiments indicate relatively high optimum temperature and salinity for growth, conditions different from those ofwinter in Texas. Because previous laboratory experiments were of short duration, it was suggested that long-term culturing of many generations could allow physiological and epigenetic changes, as well as natural selection to take place, leading to improved growth performance at low temperature and salinity. In this study, the growth and toxicity of P. parvum was investigated under relatively low temperature …

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Failure Assessment In Aerospace Systems Via Integrated Multi-Functional Sensors, Ismail Erkin Gonenli Jan 2010

Failure Assessment In Aerospace Systems Via Integrated Multi-Functional Sensors, Ismail Erkin Gonenli

Electrical Engineering Dissertations - Archive

Integrated sensors fabricated on flexible substrates show lots of promise due to their ability to conform on non-planar surfaces. Potential applications could be smart-skin and wearable electronics which can be used on prosthetic devices or in harsh environments to provide with the sense of feel of the ambient. Design, fabrication and characterization of MEMS piezoresistive pressure sensors and capacitive accelerometers were done on Si and flexible polymer substrates using surface micromachining to be used on aerospace applications. Devices were successfully tested on planar surfaces.For the pressure sensor fabrication, Si3N4 was used as a membrane material due to its linearity and …

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The Self-Heating Effects Of Bipolar Juction Transistors On The Functionality Of A Current Feedback Amplifier, Xuesong Xie Jan 2010

The Self-Heating Effects Of Bipolar Juction Transistors On The Functionality Of A Current Feedback Amplifier, Xuesong Xie

Electrical Engineering Dissertations - Archive

Self-heating effects strongly affect the performance of modern silicon-on-insulator (SOI) bipolar junction transistors. This research work does an extensive analysis of self-heating effects on large-signal behavior, small-signal behavior and transient operation of bipolar junction transistors. The two mechanisms in which device temperature affects large-signal behavior of a BJT transistor are investigated, i.e. the common-emitter (CE) configuration is to be driven by a constant base-emitter voltage and a constant base current. It is shown that the output characteristic of a BJT transistor is less sensitive to self-heating under a fixed base current than a fixed base-emitter voltage. A simple method of …

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High Detectivity Pyroelectric Infrared Detector, Annand Balasubramaniyam Jan 2010

High Detectivity Pyroelectric Infrared Detector, Annand Balasubramaniyam

Electrical Engineering Theses - Archive

The sensors which measure physical quantities by sensing them as thermal quantities and then converting the thermal signals into electrical signals are called thermal sensors. One such type of thermal sensor is a pyroelectric infrared sensor. Thermal sensors are not popular mainly because they are slow devices, and they have low sensitivity when compared to photon detectors. One major advantage of thermal detectors over photon detectors is that they can operate at room temperature. This is one of the main motivations for this research. The aim of the thesis is to design an uncooled, high detectivity pyroelectric infrared detector. The …

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Charge Pump Circuit, Paras Shah Jan 2010

Charge Pump Circuit, Paras Shah

Electrical Engineering Theses - Archive

The sole aim of this work is to show how to generate higher voltages greater than the power supply voltage. This idea is implemented using transistors and capacitors on silicon and is called a charge pump circuit. A charge pump circuit is implemented as a voltage doubler circuit in this work using 0.25um gate length technology. A 6-stage Dickson charge pump circuit was designed to produce a 15 V output from a 5 V supply using two phase non-overlapping clock signals that drive the charge pump. It also describes the advanced architectures with complex circuit design and dynamic techniques for …

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Passive Rf Sensors And Wireless Sensor Interrogation, Srikar Deshmukh Jan 2010

Passive Rf Sensors And Wireless Sensor Interrogation, Srikar Deshmukh

Electrical Engineering Theses - Archive

Recently, a new type of passive sensor called the antenna sensor has been developed. The antenna sensor incorporates a patch antenna as the sensing element as well as the data transmitting element. Physical factors such as strain and ground plane crack cause the patch antenna resonant frequency to change. By measuring the change in patch antenna resonant frequency these physical factors can be quantified.Conventional resonant frequency measurement methods require a wired connection to the antenna sensor. The wireless interrogation technique eliminates this requirement while offering all the advantages that a wireless sensor interface offers over a wired sensor interface. In …

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A High Fill Factor Cmos Image Sensor For Ir Camera Applications, Daniel Mcbride Jan 2010

A High Fill Factor Cmos Image Sensor For Ir Camera Applications, Daniel Mcbride

Electrical Engineering Theses - Archive

In this thesis, a unit cell for high-SNR applications is presented. The proposed circuit is significantly smaller than other circuits that perform dark current subtraction because less circuitry is used inside the unit cell. The proposed circuit uses only two transistors and one resistor inside each unit cell to suppress the dark current. The size of the circuit in the layout is 25 um x 25 µm. With this new unit cell and routing approach, the size of the unit cell was reduced by 300% compared to other circuits which also suppress dark current.

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Implementation Of Security Within Gen2 Protocol, Shesh Kumar Jagannatha Jan 2010

Implementation Of Security Within Gen2 Protocol, Shesh Kumar Jagannatha

Electrical Engineering Theses - Archive

In this thesis, I propose and evaluate several methods to integrate security within the identification process and memory access processes of the ISO 18000-6C (or GEN2) passive UHF radio frequency identification (RFID) protocol. The RFID Tags are promiscuous and they emit their unique identifiers in clear upon interrogation from the Reader. They do not have a mutual authentication process to validate the Readers and Tags, this allows eavesdropping, illicit reading from a malicious Reader and counterfeit Tags. GEN2 Tags are being integrated into driver's licenses and being used for border crossing identities; thus, there is a need to secure both …

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"Doubly Foreign:" British Consuls And Slavery In The Antebellum South, 1830 - 1860, Michele Anders Kinney Jan 2010

"Doubly Foreign:" British Consuls And Slavery In The Antebellum South, 1830 - 1860, Michele Anders Kinney

History Dissertations - Archive

Upon ending their slavery in the British West Indies in 1833, Great Britain became known as the "Great Emancipator." Britain immediately began an official foreign policy campaign to end the slave trade and slavery wherever it existed. In the U.S. slavery continued to be deeply rooted in the culture of the Antebellum South, causing Britain to give the region a great deal of attention based upon British ethical, moral, and ideological concerns over slavery and the trade. Between 1833 and 1860, activities associated with southern slavery created unique moral and ethical challenges for the Foreign Office and British consuls sent …

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Performing Masculinity And Reconciling Class In The American West: British Gentlemen Hunters And Their Travel Accounts, 1865-1914, Gregory Kosc Jan 2010

Performing Masculinity And Reconciling Class In The American West: British Gentlemen Hunters And Their Travel Accounts, 1865-1914, Gregory Kosc

History Dissertations - Archive

This dissertation investigates accounts by British gentlemen of the upper-middle and upper class, whose hunting narratives in the Western United States in the second half of the nineteenth century reveal their sentiments toward issues of nation, race, class, and gender. I argue that hunting accounts set in the American West, where egalitarianism and nationalism ran strong, allowed these hunters to reconcile themselves to the increasing democratization, professionalization, and commercialization of Britain and the emergence of a multi-polar global power structure by crafting an upper-class identity that reaffirmed British supremacy and class values. At the core of this upper-class identity was …

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Romilly And Rush: The Parallel Paths Of Penal Reform In Britain And America, 1780 - 1830, Wendell Allen Hunnicutt Jan 2010

Romilly And Rush: The Parallel Paths Of Penal Reform In Britain And America, 1780 - 1830, Wendell Allen Hunnicutt

History Dissertations - Archive

After the end of the American Revolution, efforts were made in both American and in Britain to alter the penal code in order to reduce the number of offenses that carried the death penalty and to replace capital punishment with incarceration in a penitentiary. In Pennsylvania, Dr. Benjamin Rush achieved apparent success in this matter since, by the time of his death, the local jail was well on its way to being transformed into the total penal institution recognizable in the nineteenth-century penitentiary. Sir Samuel Romilly, on the other hand, faced relentless opposition in Parliament in his efforts to repeal …

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True Barbarians?: The Role Of Visigothic Iberia In Medieval Persecutory Discourse, Justin T. Dellinger Jan 2010

True Barbarians?: The Role Of Visigothic Iberia In Medieval Persecutory Discourse, Justin T. Dellinger

History Theses - Archive

During the last twenty-five years, there has been wide-spread debate about the extent of the notion of persecution in medieval Europe. Those who believe that persecution existed deliberate to what extent, as well as when and where it took place. Historians who doubt it offer explanations of toleration, coexistence/convivencia, ambivalence, or simply repression. Most of this historical debate unfortunately tends to center itself in or after the eleventh-century, abstaining from discussions about socio-politico groups that existed in the fifth through tenth centuries. Groups such as the Visigoths are therefore largely omitted from these conversations. Compounding this deficiency is an issue …

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Saviors In The South: Restoring Humanity To Irish Famine Immigrants In New Orleans, 1847-1880, Merry Jett Jan 2010

Saviors In The South: Restoring Humanity To Irish Famine Immigrants In New Orleans, 1847-1880, Merry Jett

History Theses - Archive

My thesis begins in during the Irish Famine in 1847, and follows Irish emigrants across the Atlantic Ocean to New Orleans where they faced disease, poverty, and prejudice. During the Irish famine, epidemics struck across class lines and locality, decimating the Irish population. In both the city and the country, the largest providers of care were church dispensaries. Set up in every parish, dispensaries provided care to those who otherwise would have had none at all. Like doctors at the time, dispensaries were unable to eradicate the epidemics, but because they were the most widely used medical facility, they were …

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Quantitative Variation Of Blood Pressure Dynamics During Sleep Apnea, Raichel Mary Alex Jan 2010

Quantitative Variation Of Blood Pressure Dynamics During Sleep Apnea, Raichel Mary Alex

Bioengineering Theses - Archive

Sleep Apnea is one of the major sleep disorders characterized by complete cessation or decline in breathing for about 10s or more during sleep, thereby adversely affecting the quality of sleep. Studies show that about 6 % of the US adult population suffers from obstructive sleep apnea, which in turn plays a major role in the development of hypertension, heart failure, stroke and is also responsible for reduced performance in everyday activities due to lack of quality sleep. In this study the physiological response to sleep apnea were determined using beat to beat blood pressure in both healthy subjects and …

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Innovations In ¹H Mr Tissue Oximetry: New Probes And Pulses, Ujjawal Rastogi Jan 2010

Innovations In ¹H Mr Tissue Oximetry: New Probes And Pulses, Ujjawal Rastogi

Bioengineering Theses - Archive

Low oxygenation level (hypoxia) of tissue leads to cellular dysfunction, damage and poor response to therapy. Quantitative measurement of tissue oxygenation is critical not only for the study of tissue physiology, but could also help improve efficacy of therapeutic procedures. Our group has previously developed and implemented a novel approach to quantify oxygen tension in tissue using ¹H MRI, known as “PISTOL” (Proton Imaging of Siloxanes to map Tissue Oxygenation Levels). It exploits a linear relationship between the longitudinal relaxation rate (R1) and oxygen tension (pO₂) of a reporter molecule (probe). Due to close proximity of fat (~ 1 ppm) …

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A Study Of The Physiological Effects Of Sleep Apnea On Cerebral Blood Flow Velocity, Gauri Bhave Jan 2010

A Study Of The Physiological Effects Of Sleep Apnea On Cerebral Blood Flow Velocity, Gauri Bhave

Bioengineering Theses - Archive

It is estimated that sleep apnea is prevalent in the US in about 18 million people. The prevalence rate is approximately 6% in the US. Sleep apnea reduces the quality of life of patients. Sleep apnea is characterized by repetitive pauses in breathing during sleep. Recent studies also show loss of gray matter in people diagnosed with sleep apnea. To study the physiological effects of sleep apnea on cerebral blood flow velocity (CBFV), CBFV was measured in subjects simulating apnea. Sixteen volunteers (29 ± 5 yr and BMI 24.1±4.8, 9M and 7F) were recruited as control subjects. We measured CBFV …

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An Investigation Of Peripheral Blood Volume And Oxygen Saturation Change In Obstructive Sleep Apnea, Swathi Iyer Jan 2010

An Investigation Of Peripheral Blood Volume And Oxygen Saturation Change In Obstructive Sleep Apnea, Swathi Iyer

Bioengineering Theses - Archive

Obstructive sleep apnea (OSA) is a type of sleep disordered breathing in which the airway collapse partially or fully and causes arousal to resume breathing. In a 2009 National sleep foundation poll of 1000 people, 63% of men and 50% of the females showed signs of sleep apnea. It also showed that subjects with sleep apnea have high risk of high blood pressure, stroke and mental disorders such as depression especially in female. Also by another group of researcher it has been shown that the prevalence of OSA is 4% in male and 2% in female. It has been also …

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In Vivo Tracking Of Mesenchymal Stem Cell Recruitment To Tissue Scaffolds, Manwu Sun Jan 2010

In Vivo Tracking Of Mesenchymal Stem Cell Recruitment To Tissue Scaffolds, Manwu Sun

Bioengineering Theses - Archive

The term "Stem cells" has been extensively used to describe precursor undifferentiated cells that have the capacity to self-renew and can also give rise to multiple tissue types. Many studies have been shown improved functional outcome after treated with stem cell therapy. However, almost all of these investigations were analyzed based on histological evaluations which are time-consuming, expensive and fail to provide 3 dimensional and real-time information about stem cell responses. Therefore, there is a need for the development of new method to investigate the migration of stem cells in vivo. Recent evidence supports that fluorescence imaging system offer both …

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Attenuation Based Quantification Of Interstitial Lung Disease Using High Resolution Computed Tomography And Correlation With Pulmonary Function Tests, Snehal S. Watharkar Jan 2010

Attenuation Based Quantification Of Interstitial Lung Disease Using High Resolution Computed Tomography And Correlation With Pulmonary Function Tests, Snehal S. Watharkar

Bioengineering Theses - Archive

Interstitial lung disease (ILD) is a chronic and progressive pulmonary disease of the lung parenchyma resulting in fibrotic scar formation of the pulmonary alveoli. The pathologic changes in the lung result in restrictive impairment of lung function. High resolution computed tomography (HRCT) of the chest has become an essential technique in diagnosing and assessing the extent of ILD. Clinical evaluation by HRCT is usually qualitative, leading to inter-observer variability particularly in detecting early disease. We propose a quantitative attenuation-based analysis to standardize the assessment of regional lung disease. We hypothesize that early ILD is associated with greater regional heterogeneity than …

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Explorations Of Aspects Of Mixotrophy Using Mathematical Models, Kenneth W. Crane Jan 2010

Explorations Of Aspects Of Mixotrophy Using Mathematical Models, Kenneth W. Crane

Biology Dissertations - Archive

This work examined three theoretical aspects of mixotrophy, the simultaneous use of phototrophic and heterotrophic nutritional modes, and one practical application. The first study addressed the coexistence of microorganisms pursuing diverse nutritional strategies. It was found that in the range of model environments explored that all four types of organisms were predicted to persist for certain parameter combinations. The most successful mixotrophs were predicted to be primarily autotrophic, supplementing photosynthesis with bacterivory. The second study extended the first one by focusing on the effects of environmental parameters governing resource supplies and the responses of populations and ecosystem properties in relation …

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A Report On The Strategic Economic Development Plan For North Richland Hills 2011., Fatema Ali, Elizabeth Bowlen, Shon Brooks, Danielle Guillory, William Neely, Julius Owino Jan 2010

A Report On The Strategic Economic Development Plan For North Richland Hills 2011., Fatema Ali, Elizabeth Bowlen, Shon Brooks, Danielle Guillory, William Neely, Julius Owino

Public Administration Capstone Reports - Archive

The City of North Richland Hills requested that the student team make a comparative analysis of business development and retention practices in cities of comparable size. In order to suggest strategies to attract and retain businesses in North Richland Hills, the team was requested to conduct research within the business community and communicate with developers and industry leaders. Qualitative findings were compared and are presented in this report along with academic research on business development in the North Texas area. The team found that the strategy in North Richland Hills is similar to that of the other communities in the …

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Evaluation Of A Web-Phone Intervention System On Preventing Smoking Relapse, Wu-Der Peng Jan 2010

Evaluation Of A Web-Phone Intervention System On Preventing Smoking Relapse, Wu-Der Peng

Social Work Dissertations - Archive

This randomized-controlled-trial aimed to evaluate the effectiveness of a web-phone intervention system in preventing smoking relapse. The intervention was based on the Transtheoretical Model (TTM), incorporated with Motivational Interviewing strategies, and the Two-phase Model. One hundred and sixteen volunteer subjects were recruited from the student smokers name list of a university located in southern Taiwan. They were randomly assigned to three groups with a double-blind principle. The findings are listed as below. After receiving a one-month intensive intervention, the subjects in the experimental group significantly improved on self-efficacy and stage of change toward smoking cessation. After receiving a one-month intensive …

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A Micromechanics Model Of Thermal Expansion Coefficient In Fiber Reinforced Composites, Nittapon Srisuk Jan 2010

A Micromechanics Model Of Thermal Expansion Coefficient In Fiber Reinforced Composites, Nittapon Srisuk

Mechanical and Aerospace Engineering Theses - Archive

Fiber reinforced composites are widely used for the various applications in the aerospace, automotive, infrastructures and sporting goods industries. The evaluations of its mechanical and thermal properties are needed for accurate estimation of their structural response. In this study, a mathematical closed-form expression of unit cell model was developed to estimate the coefficient of thermal expansion (CTE) along longitudinal and transverse directions of unidirectional lamina. Unlike the previous models, the present model takes into consideration of the fiber configuration and volume fraction of each constituent in the unit cell. In addition, the model is also able to obtain the stresses …

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Dynamic Thermal Management Of Multi Core Processors Using Core Hopping, Avinash Raghu Jan 2010

Dynamic Thermal Management Of Multi Core Processors Using Core Hopping, Avinash Raghu

Mechanical and Aerospace Engineering Theses - Archive

Multi core processors are the order of the day today. The demand for greater levels of performance and the consequent increase in design complexity have rendered the single core processor obsolete and resulted in more cores being put onto a single chip. Processors incorporating more than 4 cores on a chip are dubbed many core processors. This, while improving performance, has lead to increased power densities. Also, the power distribution across the die surface is not uniform. These factors together, result in heat being concentrated at specific points on the die surface, called `hot spots'.The increase in die temperature results …

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Mean Pressure Measurements Of Micro-Vortex Generator At Mach 2.5, Yusi Shih Jan 2010

Mean Pressure Measurements Of Micro-Vortex Generator At Mach 2.5, Yusi Shih

Mechanical and Aerospace Engineering Theses - Archive

Shock wave/boundary layer interactions (SBLIs) are always an important issue for high-speed vehicles. SBLIs reduce the performance of aerodynamic surfaces and engine inlets, amongst a number of adverse effects. Micro-vortex generators (MVGs) are a potential flow control method that has seen intense investigation recently and have even been implemented in actual configurations at low speeds. The present research is focused on the mean pressures at Mach 2.5 around an MVG. Experiments were performed with a baseline flat plate and also with two MVG configurations (70 and 45 trailing edge) mounted ahead of a 5° ramp. In the present study MVGs …

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Axial Wave Propagation In Truncated Cones, Bhumil A. Diwanji Jan 2010

Axial Wave Propagation In Truncated Cones, Bhumil A. Diwanji

Mechanical and Aerospace Engineering Theses - Archive

While dealing with problems of impact analysis, where the force is dependent on the time, one can use the transient analysis to compute the response. Transient wave propagation has drawn interest from a long time mainly because of the way structural members behave when subjected to high rates of loading. Solutions to these problems find applications in the design of various mechanical equipments, or any situation where rigid objects are impacting on structural members.The first part of this study deals with the axial wave propagation in cones of different apex angles using transient analysis in ANSYS. The results from the …

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