Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 41 for “"TLD"”.
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Understanding The Influence of Photon Energy On 6Mv Non Reference Dosimetry and Ct Dosimetry Using Tld and Osld
… applications: thermoluminescent dosimeters (TLD) and optically stimulated luminescent dosimeters (OSLD).</p> <p>There were two main objectives to this work. The first objective was to evaluate the energy dependence of TLD and OSLD for non-reference measurement conditions in a radiotherapy …
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Enhanced Modulation Dynamic Performance of Optically-Injected Widely-Tunable Semiconductor Lasers
… wide-wavelength tunable laser diodes (TLDs). The two major goals were to investigate how modulation properties of a TLD depend on the wavelength tuning, and how the modulation performance of a TLD can be enhanced in terms of the achievable speed and improved frequency chirping behaviour …
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Development and Implementation of The Use of Optically Stimulated Luminescent Detectors In The Radiological Physics Center Anthropomorphic Quality Assurance Phantoms
… which include thermoluminescent dosimeters (TLDs) and radiochromic film. The RPC desires to switch from TLD as the absolute dosimeter in the phantoms, to optically stimulated luminescent dosimeters (OSLDs), but a problem lies in the angular dependence exhibited by the OSLD. The purpose of …
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Impact of DTG Use During Pregnancy on Birth Outcomes of HIV-Infected Women in the Western Cape, South Africa
… shift to tenofovir+lamivudine+dolutegravir (TLD) has improved viral suppression in pregnant women living with HIV (WLH) but there are limited data on the combined impact of HIV and maternal body composition on birth outcomes. Methods: We enrolled WLH on TLD and a comparison group of women not …
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Study of mechanism of genetic death in Escherichia coli in response to A) dTTP starvation and B) combination of temperature sensitive defects in replication initiation and double strand break repair
… to dTTP starvation known as Thymineless Death (TLD). This phenomenon has been subject to decades of investigation since its discovery in 1954, and I present our recent efforts to further understand the consequences of dTTP starvation in prokaryotic cells. The other example of genetic death that …
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Commissioning of Micro-Cube Thermoluminescent Dosimeters For Small Field Dosimetry Quality Assurance In Radiotherapy
… evaluates the reproducibility and accuracy of TLD micro-cubes for use in stereotactic radiosurgery (SRS) remote auditing quality assurance (QA) for treatment centers participating in clinical trials. This study tested the hypothesis that TLD micro-cubes could be commissioned to evaluate small …
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Transfer rna dynamics and transfer-messenger rna accommodation in bacterial ribosomes at the single-molecule level
… of the tRNA-like domain of tmRNA (TLD) in complex with SmpB protein was carried out, and the results reveal no change in the global conformation or the flexibility of the TLD upon SmpB binding. In contrast, magnesium ions induce a compaction of the TLD structure, suggesting that …
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Quantification of Cervical Spine Motion During Application of a Rigid Cervical Immobilization Collar
… displacement (PAD), total linear distance (TLD), total angular distance (TAD), and application time were recorded. PAD was also recorded during the supine and seated ROM testing.</p> <p>Results: Significant differences (p < .01) between collars were noted during collar application for …
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Development and Commissioning of An Independent Peer Review System For A Small Animal Irradiator
… accommodated three thermoluminescent dosimeters (TLD) and the other an Exradin A1SL 0.053 cc ion chamber (Standard Imaging, Middleton, WI) for cross-comparison with the TLD. An acrylic irradiation stand was constructed to allow users to align the mouse phantom to the irradiator’s isocenter. …
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The use of thermoluminescent dosimeters for In-vivo dosimetry in a fast neutron therapy beam
Thermoluminescent detectors (TLD-700) have been investigated for absorbed dose measurements in a p(66)/Be neutron therapy beam at the National Accelerator Centre. Chips were selected based on their reproducibility and chip individual neutron calibration factors were derived. The dose non-linearity …
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In-Vivo Ct Dosimetry During Virtual Colonoscopy
… is currently unknown.</p> <p>In this study, two TLDs were affixed to the inner lumen of standard rectal catheters used in VC, and in-vivo rectal dose measurements were obtained within 6 VC patients. In order to calculate rectal dose, TLD-100 powder response was characterized at diagnostic doses …
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Relaçôes entre o crescimento, a dispersão e a obsolescência da literatura de dosimetria termoluminescente
An analysis of the international TLD literature using references and citations is done, based on a bibliography of 3079 items including periodical and non-periodical literature for the period 1950-1975 For lower growth rates, i.e., longer duplication periods, higher dispersion and lower …
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Implementation of An Anthropomorphic Phantom For The Evaluation of Proton Therapy Treatment Procedures
… auditing with thermoluminescent dosimeters (TLD) and mailable anthropomorphic phantoms. Currently, there are no heterogeneous phantoms that have been commissioned to evaluate proton therapy. It was hypothesized that an anthropomorphic pelvis phantom can be designed to audit treatment …
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Modification and Implementation of The Rpc Heterogeneous Thorax Phantom For Verification of Proton Therapy Treatment Procedures
… with a 15 degree couch kick. EBT2 film and TLD were inserted and the phantom was irradiated 3 times for each plan. Both plans passed the criteria for the TLD measurements where the TLD values were within 7% of the dose calculated by Eclipse. Utilizing the 5%/3mm criteria, the 3 trial average …
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The role of recombinational repair in the mechanism of killing during thymine starvation in Escherichia coli
Thymineless death (TLD) describes a universal phenomenon in which cells cannot recover after starvation for one of the four DNA precursors, dTTP. The mechanism of how cells lose viability during thymine starvation has remained a mystery for decades. In Escherichia coli, thymine-starved cells were …
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Quantifying The Magnitude of to tal Dose Deviation Caused By Various Sources of Error Among Iroc Phantom Irradiation Results
… received by the thermoluminescent dosimeters (TLDs) inside the phantom, reflects the accuracy with which an institution can image, plan and irradiate a phantom or patient. Recent phantom results show that among the hundreds of various IROC phantoms irradiated annually, 8-17% of institutions …
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Utilização de redes neurais artificiais para identificação de energia em campos fotônicos com materiais termoluminescentes
… a um sistema dosimétrico termoluminescente (TLD-700 e TLD-600). Os dosímetros foram expostos inicialmente a diversas energias médias conhecidas, entre 16 keV e 1,2 MeV, para o intervalo de doses de 0,5 a 10 mSv, com o propósito de gerar um conjunto de dados de treinamento para a rede neural. …
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Development and Implementation of An Anthropomorphic Pediatric Spine Phantom For The Assessment of Craniospinal Irradiation Procedures In Proton Therapy
… passing criteria for gamma analysis and also a TLD point dose agreement within 5%. Tissue equivalency was determined by measuring the relative stopping power and Hounsfield unit of potential phantom materials. The materials selected as bone, tissue, and cartilage substitutes were Techron HPV …
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Commissioning An Anthropomorphic Spine and Lung Phantom For Remote Dose Verification of Institutions Participating In Rtog 0631
… film and thermoluminescent dosimeters (TLD). The dose distributions were measured with the radiochromic film calibrated to the absolute dose measured by the TLD. Four irradiations were administered: a four angle box plan, a seven angle conformal plan, a seven angle IMRT plan, and a nine …
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2X-Thru, 1X-Reflection, and Thru-Line de-embedding: Theory, sensitivity analysis, and error corrections
… de-embedding (1XRD), and Thru-Line de-embedding (TLD) have been replaced the traditional de-embedding algorithms, such as TRL and SOLT. In this dissertation, theory of 2<sup>n</sup>-port 2XTD, 1XRD, and TLD are completely derived first. The self-error reduction schemes is introduced to mitigate …
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