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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.
31

Investigation into Characteristics of Bench Press using PUSH™ Band

Peters, Avery, Sato, Kimitake 12 April 2019 (has links)
Abstract Investigation into Characteristics of Bench Press using PUSH™ Band Peters, Avery1 and Sato, Kimitake1 Department of Sport, Exercise, Recreation, and Kinesiology, East Tennessee State University, Johnson City, TN1 Introduction: Sport scientist and strength coaches use resistance training to increase athletic performance and muscle hypertrophy. Improving muscular strength is the most essential task for these scientists, however, how best to identify weakness has yet to be established. The popularity of velocity-based resistance training has recently increased as a method to prescribe resistance training intensity, therefore, the purpose of the study was to identify the characteristics of bench press concentric velocity. It is hypothesized that the velocity output will decrease during the change from the 75% relative load of the 1RM to the 85% relative load of 1RM. It is believed that there will be a greater output of velocity during the 75% set than the 85% set. Methods: Nine female collegiate athletes (18-21 yrs), participated in this study. PUSH™ bands were used to measure barbell velocity during the bench press exercise. Each female was expected to preform 3 sets of 5 repetitions (3x5) at an intensity of 75% and 85% of their 1 repetition maximum (1RM). Only data from repetition 2-4 were used for analysis. Results: The results drawn from data collected supported our hypothesis showing a decrease in velocity among the 85% 1RM test when compared to the 75% 1RM test group. Comparisons were drawn using a t-Test table comprised of PUSH™ Band data. Conclusion: The results supported the hypothesis that this type of technology can identify the load specific velocity to help strength coaches to identify the optimal resistance for certain training program and goals by using collected data with the PUSH™ Band to identify weakness in strength and/or endurance.
32

Time-Dependent Neutron and Photon Dose-Field Analysis

Wooten, Hasani Omar 24 June 2005 (has links)
A unique tool is developed that allows the user to model physical representations of complicated glovebox facilities in two dimensions and determine neutral-particle flux and ambient dose-equivalent fields throughout that geometry. The code Pandemonium, originally designed to determine flux and dose rates only, has been improved to include realistic glovebox geometries, time-dependent source and detector positions, time-dependent shielding thickness calculations, time-integrated doses, a representative criticality accident scenario based on time-dependent reactor kinetics, and more rigorous photon treatment. The photon model has been significantly enhanced by expanding the energy range to 10 MeV to include fission photons, and by including a set of new buildup factors, the result of an extensive study into the previously unknown "purely-angular effect" on photon buildup. Purely-angular photon buildup factors are determined using discrete ordinates and coupled electron-photon cross sections to account for coherent and incoherent scattering and secondary photon effects of bremsstrahlung and florescence. Improvements to Pandemonium result in significant modeling capabilities for processing facilities using intense neutron and photon sources, and the code obtains comparable results to Monte Carlo calculations but within a fraction of the time required to run such codes as MCNPX.
33

Procena doza i optimizacija protokola pri standardnim pregledima višeslojnom kompjuterizovanom tomografijom / Assessment of dosage and optimization of protocol at standard examinations with multislice computerized tomography

Hadnađev Šimonji Darka 21 December 2015 (has links)
<p>Kompjuterizovana tomografija (CT) je jedan od najznačajnijh dijagnostičkih modaliteta, čija upotreba raste iz decenije u deceniju. U ukupnom broju radiolo&scaron;kih pregleda CT je zastupljena sa 5-10%, ali je njen doprinos ukupnoj dozi za populaciju veći od 50%. Osnovni pokazatelji kvaliteta slike i doza, kao i prateći radijacioni rizik zavise od primenjene radiografske tehnike odnosno CT pregleda. U smislu&nbsp; dobre radiolo&scaron;ke prakse i u skladu sa osnovnim principima za&scaron;tite od zračenja, poželjna je primena najniže moguće doze za pacijenta uz održavanje kvaliteta slike i dijagnostičke informacije. Cilj istraživanja jeste definisanje optimalnog protokola pregleda vi&scaron;eslojnom CT za dijagnozu pojedinih regija tela, kao i da se utvrde doze i radijacioni rizik za pacijente pre i nakon optimizacije protokola. Analizom je obuhvaćeno ukupno 437 pacijenata, koji su podeljeni u grupe prema regijama tela koje su snimane: I&ndash;nekontrastni CT glave, II-CT glave sa i.v. kontrastom, III-CT grudnog ko&scaron;a, IV-CT abdomena i karlice i V-CT angio (CT angiografija aortoilijačnog segmenta i donjih ekstremiteta). Studija je izvedena u 2 faze: u I fazi je kori&scaron;ćen standardni protokol za regiju tela koja se snimala, a u II fazi CT pregledi su izvedeni po modifikovanom protokolu (promenom parametra vrednosti mAs), uz minimalne zahteve u pogledu kvaliteta slike.Na osnovu dozimetrijskih&nbsp; pokazatelja procenjena je efektivna doza i radijacioni rizik za pacijente u obe faze. U studiji su kori&scaron;ćene smernice iz Vodiča EUR 16262&nbsp; EN, u kojima su definisani parametri za procenu kvaliteta slike da bi se analizirali različiti anatomski preseci određenih regija tela koji su se snimali. Kvalitet slike za svakog pacijenta je ocenjen pomoću trostepene skale vizualizacije za svaki parametar anatomske regije: 0-detalji su vidljivi, 1-detalji se prikazuju, 2-detalji se jasno prikazuju. Kori&scaron;ćena je subjektivna metoda gde su dva iskusna radiologa vr&scaron;ili interpretaciju slike. Konačna ocena kvaliteta slike svakog pregleda odgovara zbiru svih parametara procenjenih po trostepenoj skali&nbsp; vizualizacije. Zatim je za potrebe izračunavanja veličine FOM (figure of merit) izračunata vrednost indeksa ocene kvaliteta slike (zbir svih&nbsp; ocena parametra/brojem parametara). Vrednost FOM je izračunata kao količnik indeksa ocene kvaliteta slike i efektivne doza po pacijentu. Prosečna vrednost FOM za svaku grupu ispitanika nam je poslužila kao relativni pokazatelj za upoređivanje između neoptimizovane i optimizovane grupe ispitanika za isti tip pregleda. Poređenjem vrednosti efektivne doze u prvoj i drugoj fazi istraživanja kvantifikovano je smanjenje radijacionog opterećenja za pacijente nakon optimizacije protokola. Rezultati su pokazali da je optimalnim izborom protokola u&nbsp;&nbsp; smislu parametara ekspozicije (smanjenjem vrednosti mAs) moguće značajno smanjiti dozu zračenja kod pregleda glave za 7,5%, kod pregleda glave sa angiografijom za 7%, kod pregleda grudnog ko&scaron;a za 40%, kod pregleda abdomena i karlice za 25%. Grupa CT angio&nbsp; nije mogla da bude optimizovana, jer aparat nije prihvatao promenu kvaliteta slike kod zadatih parametara optimizacije. Primenom standardnih protokola postiže se kvalitet slike bolji nego &scaron;to je neophodno, a samim tim i veća doza zračenja nego &scaron;to je potrebno. Optimalnim izborom protokola u smislu parametara ekspozicije moguće je značajno smanjiti dozu zračenja, uz održavanje kvaliteta slike koji je dovoljan za adekvatnu radiolo&scaron;ku interpretaciju slike.</p> / <p>Computed&nbsp; tomography (CT) is one of the most significant diagnostic methods whose application has been increasing from decade to decade.&nbsp; Among the total number of radiological examinations CT accounts for 5-10%, however, its contribution in the whole dosage for the population is greater than 50%. Main indicator of the quality of images and dosages as well as the accompanying irradiation risk depend on applied radiographic technique that is CT examination. In the sense of good radiological practice and in accordance with basic principles of protection from irradiation, the application of the lowest possible dosage for a patient together with preserving the quality of image and diagnostic information are mostly welcomed. The goal of the research is to define the optimum examination protocol by multislice CT in diagnostics of certain body regions as well as to determine dosages and irradiation risk for patients both before and after protocol optimization. The analysis has included 437 patients divided into groups according to body regions which have been scanned: I-unenhanced head CT, II contrast enhanced head CT, III&ndash;chest CT, IV&ndash;abdomen and pelvis CT and&nbsp; V&ndash;angio CT (CT angiography of aortoiliac segment and lower extremities). The study has been conducted in 2 phases: in the first phase standard protocol for the scanned body region has been applied, and in the second phase CT examinations have been carried out according to the modified&nbsp; protocol&nbsp; (by change of parameters of values mAs)&nbsp; with minimum&nbsp; requirements&nbsp; regarding&nbsp; the&nbsp; image&nbsp; quality. On&nbsp; the&nbsp; basis&nbsp; of&nbsp; dosimetric&nbsp; indicators&nbsp; the&nbsp; efficient&nbsp; dosage&nbsp; and&nbsp; irradiation&nbsp; risk&nbsp; for&nbsp; the patients in both phases have been assessed. In the study the guidelines form the Guide EUR&nbsp; 16262&nbsp; EN&nbsp; have&nbsp; been&nbsp; observed&nbsp; where&nbsp; parameters for&nbsp; the&nbsp; assessment&nbsp; of&nbsp; image quality&nbsp; have&nbsp; been&nbsp; defined&nbsp; in&nbsp; order&nbsp; to&nbsp; analyze&nbsp; different&nbsp; anatomic&nbsp; cross sections of certain body&nbsp; regions.&nbsp; Image quality&nbsp; for&nbsp; each&nbsp; patient&nbsp; was&nbsp; assessed&nbsp; by&nbsp; three-level visualization&nbsp; scale&nbsp; for&nbsp; each&nbsp; parameter&nbsp; of&nbsp; anatomic&nbsp; region:&nbsp; 0&ndash;details&nbsp; are&nbsp; visible, 1&ndash;details are&nbsp; presented,&nbsp; 2&ndash;details are clearly&nbsp; presented.&nbsp; A&nbsp; subjective&nbsp; method&nbsp; was applied&nbsp; where&nbsp; two&nbsp; experienced&nbsp; radiologists performed&nbsp; the&nbsp; image interpretation. Final assessment&nbsp; of&nbsp; image quality&nbsp; of&nbsp; every&nbsp; examination corresponds&nbsp; to&nbsp; the&nbsp; sum&nbsp; of&nbsp; all parameters&nbsp; according&nbsp; to&nbsp; three-level&nbsp; visualization&nbsp; scale. Further,&nbsp; for&nbsp; the&nbsp; need&nbsp; of calculation of the size of FOM (figure of merit) the value of the index of assessment of the&nbsp; image&nbsp; quality&nbsp; (sum of all assessments of parameters/number of&nbsp; parameters) has been&nbsp; calculated.&nbsp; The&nbsp; value of&nbsp; FOM&nbsp; has&nbsp; been&nbsp; calculated as a quotient&nbsp; of&nbsp; the&nbsp; image quality assessment index and effective dosage per patient.&nbsp; The average value of FOM for&nbsp; every&nbsp; group&nbsp; of&nbsp; patients&nbsp; has&nbsp; offered us a&nbsp; relative&nbsp; indicator for&nbsp; comparison of&nbsp; non-optimum&nbsp; and optimum group of&nbsp; patients&nbsp; for&nbsp; the&nbsp; same&nbsp; type&nbsp; of&nbsp; examinations.&nbsp; By comparison of values of effective dosage in the first and second phase of the research a decrease in irradiation load for patients after protocol optimization was quantified. The results have&nbsp; shown&nbsp; that&nbsp; by&nbsp; optimum&nbsp; protocol&nbsp; selection&nbsp; in&nbsp; the&nbsp; sense&nbsp; of&nbsp; exposition parameters (by&nbsp; reduction of&nbsp; values of&nbsp; mAs) it is&nbsp; possible to reduce significantly&nbsp; the irradiation dosage at&nbsp; unenhanced head CT examination for 7,5%, at contrast enhanced head CT examination for 7%, at chest CT examination for 40%, at abdomen&nbsp; and pelvis CT examination for 25%. The group CT angio could not be optimized since the device&nbsp; did&nbsp; not&nbsp; accept&nbsp; the&nbsp; change in image quality at set&nbsp; optimization parameters. By application&nbsp; of&nbsp; standard&nbsp; protocols the image quality&nbsp; better&nbsp; than required&nbsp; was&nbsp; achieved and along with this, a higher irradiation dosage occurred than required. By selection of protocol in the sense&nbsp; of&nbsp; exposition parameters it is possible to reduce irradiation dosage significantly along with preserving image quality which is&nbsp; sufficient for adequate radiological image interpretation.</p>

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