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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Design and Selection of RT-LAMP Primer Sets Targeting SARS-CoV-2 in Complex Human Samples

Josiah Levi Davidson (10723713) 29 April 2021 (has links)
<p>Loop-mediated Isothermal Amplification (LAMP) is a promising technology to address diagnostic and surveillance testing during public health crises, such as the current COVID-19 pandemic; however, primer design and assay optimization remain a barrier to enabling rapid deployment of assays based on LAMP. Herein, we introduce a design and screening process that allows for strategic determination of optimally performing primer sets and standardized assay conditions which enable execution of LAMP at point-of-care (POC) settings using complex human samples such as saliva. A total of 20 primer sets targeting the N, E, RdRP, and orf1ab genes of the SARS-CoV-2 were designed, screened, and selected based on performance metrics such as reaction time, sensitivity, and specificity. Of these 20 primer sets, only two primer sets (orf1ab.2 and orf1ab.4) proved to be viable for use in the final assay. Colorimetric RT-LAMP of the selected primer set, orf1ab.2 was shown to produce a distinct color change in contrived samples containing heat-inactivated SARS-CoV-2 in 5% saliva. The limit of detection of our assay using primer set orf1ab.2 was determined to be 1000 copies/µL of saliva collected. Furthermore, methods are introduced which allow for the high-throughput design of LAMP primers using standard software tools and the <i>in-silico</i> performance of LAMP primer sets. </p>
22

A Web-Based Database Application as an Analysis Tool for Energy Use and Carbon Dioxide Emission

Turan, Biray Jr January 2009 (has links)
<p>The aim of this thesis project was to migrate an existing excel-based application, used</p><p>to analyze energy use and carbon dioxide emission of companies, to a web-based application.</p><p>Special development questions were put around which software development process,</p><p>solution stack and user interface to be used according to the company needs. The spiral</p><p>lifecycle model has been chosen because it provides a clear view of the process and has the</p><p>concept of early prototypes. A solution stack based on Linux, Apache, PHP and MySQL has</p><p>been chosen because such approach has met the company requirements in terms of cost,</p><p>security, support, and maintenance. As a result, the developed web-based system overcomes</p><p>the problems normally found in excel-based applications, such as application deployment and</p><p>maintenance, and provides a more usable and richer user interface.</p>
23

A Web-Based Database Application as an Analysis Tool for Energy Use and Carbon Dioxide Emission

Turan, Biray Jr Unknown Date (has links)
<p>The aim of this thesis project was to migrate an existing excel-based application, used</p><p>to analyze energy use and carbon dioxide emission of companies, to a web-based application.</p><p>Special development questions were put around which software development process,</p><p>solution stack and user interface to be used according to the company needs. The spiral</p><p>lifecycle model has been chosen because it provides a clear view of the process and has the</p><p>concept of early prototypes. A solution stack based on Linux, Apache, PHP and MySQL has</p><p>been chosen because such approach has met the company requirements in terms of cost,</p><p>security, support, and maintenance. As a result, the developed web-based system overcomes</p><p>the problems normally found in excel-based applications, such as application deployment and</p><p>maintenance, and provides a more usable and richer user interface.</p>
24

Investigations of equine sarcoids and bovine papillomavirus in Western Canada

Wobeser, Bruce 25 February 2011
Equine sarcoids are the most common skin tumors of horses. Despite being such a common entity, relatively little is known about many features of sarcoid epidemiology or growth. In addition, due to the detection of Bovine Papillomavirus (BPV) DNA of 2 different types, BPV type 1 (BPV1) and BPV type 2 (BPV2), in equine sarcoids BPV has been suggested as the causative agent of sarcoid development. Recently, however, BPV DNA has also been detected in other skin conditions of horses; the significance of this is unclear. Multiple studies to learn more about sarcoids were undertaken.<p> To investigate the epidemiology of sarcoids in horses in Western Canada the records of five veterinary diagnostic laboratories were searched to identify submissions of sarcoids from horses. The submission record and diagnostic reports of 802 separate submissions of equine sarcoids were reviewed for age, breed, and gender of the horse and the number, location and clinical type of sarcoid. Based on these submissions, horses of a wide variety of ages and 23 different equine breeds were affected, within these breeds, Donkeys were overrepresented.<p> The presence of BPV was determined by Polymerase Chain Reaction (PCR). BPV was found in 74 of 96 (77.1%) samples, and using Restriction Fragment Length Polymorphism, BPV1 and BPV2 were identified in these samples. BPV2 was present in 59 (79.7%) of these. Unlike other areas in the world, in Western Canada, equine sarcoids are most commonly associated with BPV2.<p> A second study examined different clinical types of sarcoids to determine if there was differential expression of immunohistochemical markers associated with apoptosis, Cleaved Caspase 3(ClC3), and antiapoptotic factors, B-Cell Lymphoma 2 (Bcl-2) and Survivin. No differences in the expression of any of these markers regardless of BPV type were noted. Survivin was expressed in equine sarcoids of all types and increased levels of expression are associated with more aggressive clinical behaviour.<p> Finally, the location of BPV DNA was determined in both sarcoids and a variety of non-sarcoid inflammatory skin conditions of horses, as well as, normal skin. PCR for BPV DNA was performed on 86 skin biopsies from horses with non-sarcoid skin conditions, as well as, normal skin. BPV DNA was present in 41 of 86 biopsies. These positive samples, in addition to BPV positive sarcoid samples from the earlier study, were dissected into tissue compartments using laser microdissection followed by 2 forms of BPV DNA amplification, PCR and isothermal loop mediated amplification. BPV DNA was more often located in the epidermis of non-sarcoid skin conditions than in sarcoids. In addition, areas of inflammation within the dermis and epidermis were more likely to contain BPV DNA than non-inflamed areas. These results suggest that while BPV is commonly found in equine skin, the location where it is found differs between sarcoids and non-sarcoid samples. When BPV DNA was found in non-sarcoid samples, it was commonly associated with inflammation suggesting that microscopic damage to the epidermal barrier of the skin maybe an adequate predisposing factor to the development of sarcoids.
25

A Web-Based Database Application as an Analysis Tool for Energy Use and Carbon Dioxide Emission

Turan, Biray Jr January 2009 (has links)
The aim of this thesis project was to migrate an existing excel-based application, used to analyze energy use and carbon dioxide emission of companies, to a web-based application. Special development questions were put around which software development process, solution stack and user interface to be used according to the company needs. The spiral lifecycle model has been chosen because it provides a clear view of the process and has the concept of early prototypes. A solution stack based on Linux, Apache, PHP and MySQL has been chosen because such approach has met the company requirements in terms of cost, security, support, and maintenance. As a result, the developed web-based system overcomes the problems normally found in excel-based applications, such as application deployment and maintenance, and provides a more usable and richer user interface.
26

A Web-Based Database Application as an Analysis Tool for Energy Use and Carbon Dioxide Emission

Turan, Biray Jr Unknown Date (has links)
The aim of this thesis project was to migrate an existing excel-based application, used to analyze energy use and carbon dioxide emission of companies, to a web-based application. Special development questions were put around which software development process, solution stack and user interface to be used according to the company needs. The spiral lifecycle model has been chosen because it provides a clear view of the process and has the concept of early prototypes. A solution stack based on Linux, Apache, PHP and MySQL has been chosen because such approach has met the company requirements in terms of cost, security, support, and maintenance. As a result, the developed web-based system overcomes the problems normally found in excel-based applications, such as application deployment and maintenance, and provides a more usable and richer user interface.
27

Investigations of equine sarcoids and bovine papillomavirus in Western Canada

Wobeser, Bruce 25 February 2011 (has links)
Equine sarcoids are the most common skin tumors of horses. Despite being such a common entity, relatively little is known about many features of sarcoid epidemiology or growth. In addition, due to the detection of Bovine Papillomavirus (BPV) DNA of 2 different types, BPV type 1 (BPV1) and BPV type 2 (BPV2), in equine sarcoids BPV has been suggested as the causative agent of sarcoid development. Recently, however, BPV DNA has also been detected in other skin conditions of horses; the significance of this is unclear. Multiple studies to learn more about sarcoids were undertaken.<p> To investigate the epidemiology of sarcoids in horses in Western Canada the records of five veterinary diagnostic laboratories were searched to identify submissions of sarcoids from horses. The submission record and diagnostic reports of 802 separate submissions of equine sarcoids were reviewed for age, breed, and gender of the horse and the number, location and clinical type of sarcoid. Based on these submissions, horses of a wide variety of ages and 23 different equine breeds were affected, within these breeds, Donkeys were overrepresented.<p> The presence of BPV was determined by Polymerase Chain Reaction (PCR). BPV was found in 74 of 96 (77.1%) samples, and using Restriction Fragment Length Polymorphism, BPV1 and BPV2 were identified in these samples. BPV2 was present in 59 (79.7%) of these. Unlike other areas in the world, in Western Canada, equine sarcoids are most commonly associated with BPV2.<p> A second study examined different clinical types of sarcoids to determine if there was differential expression of immunohistochemical markers associated with apoptosis, Cleaved Caspase 3(ClC3), and antiapoptotic factors, B-Cell Lymphoma 2 (Bcl-2) and Survivin. No differences in the expression of any of these markers regardless of BPV type were noted. Survivin was expressed in equine sarcoids of all types and increased levels of expression are associated with more aggressive clinical behaviour.<p> Finally, the location of BPV DNA was determined in both sarcoids and a variety of non-sarcoid inflammatory skin conditions of horses, as well as, normal skin. PCR for BPV DNA was performed on 86 skin biopsies from horses with non-sarcoid skin conditions, as well as, normal skin. BPV DNA was present in 41 of 86 biopsies. These positive samples, in addition to BPV positive sarcoid samples from the earlier study, were dissected into tissue compartments using laser microdissection followed by 2 forms of BPV DNA amplification, PCR and isothermal loop mediated amplification. BPV DNA was more often located in the epidermis of non-sarcoid skin conditions than in sarcoids. In addition, areas of inflammation within the dermis and epidermis were more likely to contain BPV DNA than non-inflamed areas. These results suggest that while BPV is commonly found in equine skin, the location where it is found differs between sarcoids and non-sarcoid samples. When BPV DNA was found in non-sarcoid samples, it was commonly associated with inflammation suggesting that microscopic damage to the epidermal barrier of the skin maybe an adequate predisposing factor to the development of sarcoids.
28

Investigation on Sustaining Arc Current for Metal Halide Lamps with Single-Pulse Ignition

Cheng, Jung-Cheng 06 August 2012 (has links)
This research attempts to ignite metal halide lamps once with a single-pulse to avoid the problems of uncomfortable light strobes and irregularly high voltage and current stresses on circuit components caused by multiple strikes in conventional electronic ballasts. Metal halide lamps with single-pulse ignition, however, have difficulty in sustaining the lamp arc when operated with a low-frequency square-wave current. Experimental results indicate that the lamp exhibits an extremely small equivalent resistance as the electrode gap has being broken down. In this stage, the ballast has to keep the lamp current not declining to zero in the first half cycle. On the other hand, the lamp acts like open-circuited during commutation when driven by an alternating current. A sufficient energy from the ballast is needed to continue the arc in the next half-cycle. The transition waveform of the lamp arc current after being broken down is analyzed and the required energy for sustaining the lamp arc is calculated accordingly. Based on the investigation results, a starting scenario with appropriately designed circuit parameters for single-pulse ignition can be figured out. The starting scenario has been experimentally implemented on a 70 W metal halide lamp to demonstrate that the metal halide lamp can be successfully started up with single-pulse ignition.
29

Electronic Ballasts for Fluorescent Lamps with Programmed Rapid-Start

Chen, Wei-Ming 05 July 2004 (has links)
Three programmed rapid-start control schemes for the electronic ballasts with a half-bridge series-resonant inverter are proposed to improve the starting performance of the rapid-start fluorescent lamps. Included are: (1) programmed rapid-start control scheme with an ac switch, (2) programmed rapid-start control scheme with inductively coupled filament-heating circuit, and (3) programmed frequency control scheme with a series-resonant energy-tank. The first control scheme is simply to add a solid-state ac switch onto the series-resonant electronic ballast to provide programmed rapid-start for the rapid-start fluorescent lamp. The ac switch is turned on to have a zero voltage across the lamp to eliminate the glow current during the preheating interval. By adjusting the operation frequency and the duty-ratio, the electronic ballast produces first an adequate resonant current for preheating the cathode filaments, then a sufficiently high lamp voltage for ignition, and finally a stable lamp arc of the required lamp power. The second control scheme is accomplished by adding two auxiliary windings on the inductor of the power-factor-correction (PFC) circuit for the filament-heating circuits. During the preheating period, the PFC circuit is activated to provide the filament heating while the inverter remains idle to keep the lamp voltage at zero and hence to eliminate the glow current. After the filaments have been heated to the appropriate temperature, the inverter is initiated to ignite the lamp and then operate it at the required power. The third control scheme is realized by programming the operation frequency of the electronic ballast with an additional series-resonant energy-tank on the load resonant network. During the preheating interval, the electronic ballast is programmed to operate at the resonance frequency of the series-resonant energy-tank to reduce the lamp voltage and hence to eliminate the glow discharge. With carefully designed circuit parameters, the electronic ballast is able to provide an adequate current for preheating. After the emission temperature has been reached, the operation frequency is adjusted to generate a high lamp voltage for ignition, and then is located at the steady-state frequency driving the lamp with the desired power and filament current. In this dissertation, the mode operations of the proposed ballast circuits are analyzed in accordance with the conducting conditions of the power switches. The equivalent resistance model of fluorescent lamp is implemented to calculate the performances of the ballast-lamp circuit at steady-state. The design equations are derived and the computer analyses are performed with the fundamental approximation on the equivalent circuit models of fluorescent lamps. In addition, in order to accurately predict the operating characteristic of the preheating circuit, a mathematical model is developed to interpret the variations of the filament resistance during preheating. Finally, the laboratory electronic ballasts with the proposed control schemes are built and tested. Satisfactory performances are obtained from the experimental results.
30

Life-End Detection and Protection of High-Frequency Electronic Ballast Driven Fluorescent Lamps

Lee, Cheng-Chung 19 August 2004 (has links)
The fault phenomena of fluorescent lamps are investigated by observing the operations in the last period of the life cycle. Accordingly, fault detecting and protection circuits are designed. Before coming to the life-end, the lamps can be started up, but are operated abnormally. A ruddy glow may occur at one end of the cathode filaments and an unstable arc may happen to the lamp. Obviously, the light efficiency becomes relatively low. The arc instability eventually results in a totally damaged fluorescent lamp. It is found that both waveforms of the lamp voltage and the lamp current are asymmetrical and have unequal positive and negative peak values. The asymmetry is more significant for the lamp voltage. In addition, a dc component is present in the lamp voltage. Based on these investigated results, the detection and protection circuits are designed for high-frequency electronic ballasts under dimming operations as well at the rated power. The experiments show that the detection and protection circuits can work effectively.

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