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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.
1

Mutable Detector Array Software for the Detection of Gamma Emissions in Classrooms and the Field

Hearn, Gentry Charles 2012 August 1900 (has links)
Detector arrays are required for many applications in health and defense. Whether searching for contraband or controlling radioactive spread after an event, a "passive" data collection strategy is a key component. This can take the form of portal monitors attached to a fixed location or a movable array, attached to a vehicle or person, which searches for abnormalities in the radiation background. The main goal of this project was to create software that would allow the digiBASE-E to be used to create arrays of gamma detection instruments and gather data over a long span of time. To take full advantage of the digiBASE-E, the software focused on the list mode capabilities of these devices. List mode attaches a timestamp to each detection event. Every particle detected can be traced to a particular point in time, and the full history of the device?s detection over the acquisition period can be reconstructed. The list mode ability of the digiBASE-E is a powerful tool for producing arrays of detectors, as a more familiar spectrum can be generated for any arbitrary section of time, even after-the-fact. The software package, called "CraneWow", was field tested at the Port of Tacoma in August of 2011. Perl scripts included as part of the package were used to partially analyze the data collected, allowing for verification of the proof-of-concept's success. The software was written in C/C++, with supplemental scripts written in Perl to facilitate processing of the data once collected. Additionally, a user manual and programming guide were written to allow easy use and maintenance of the software.
2

Thermal stress simulate of the Cu/Diamond/Cu multilayer heat spreader device

Chen, Hsueh-mao 08 November 2006 (has links)
The main purpose of this research is to utilize the FEMLAB multiphysics software as to analyze the thermal stress of Cu/Diamond/Cu three-layered heat spreader device. The alteration of film thickness under different temperatures(allowing the device to increase from room temperature of 27¢XC to 100¢XC, 200¢XC and 300¢XC), with upper Cu layer of 2µm, altered middle diamond layer(20µm, 50µm 100µm), and lower Cu layer(100µm, 200µm, 300µm)(assuming that there is no residual stress produced after the manufacture of heat spreader device), is regarded as the conditional parameter of heat spreader device in analyzing the deformation rate and stress variation produced. After simulation of the research, it was found out that a maximum shear stress is attained under a fixed temperature load. And, when the film thickness is altered and under a fixed thick of Cu layer, the shear stress will become bigger due to the thickness of the diamond layer increases, when the diamond layer is 50-70µm, stress increases slowly; but it is considered to be the greatest effect when the heat transfer of diamond is at 100µm; thus selection of 70µm would be a better option in this paper suggestion, and that the alteration of the thickness of lower Cu layer will not cause great effect to max shear stress.) After stabilizing the thickness of upper Cu layer and middle diamond layer, the maximum deformation rate will become smaller when the thickness of lower Cu layer increases.
3

An Analysis of a Spreader Bar Crane Mounted Gamma-Ray Radiation Detection System

Grypp, Matthew D 03 October 2013 (has links)
Over 95% of imports entering the United States from outside North America arrive via cargo containers by sea at 329 ports of entry. The current layered approach for the detection only scans 5% of cargo bound for the United States. This is inadequate to protect our country. This research involved the building of a gamma-ray radiation detection system used for cargo scanning. The system was mounted on a spreader bar crane (SBC) at the Port of Tacoma (PoT) and the applicability and capabilities of the system were analyzed. The detection system provided continuous count rate and spectroscopic data among three detectors while operating in an extreme environment. In a separate set of experiments, 60Co and 137Cs sources were positioned inside a cargo container and data were recorded for several count times. The Monte Carlo N-Particle (MCNP) code was used to simulate a radioactive source inside an empty cargo container and the results were compared to experimentally recorded data. The detection system demonstrated the ability to detect 60Co, 137Cs, 192Ir, highly-enriched uranium (HEU), and weapons-grade plutonium (WGPu) with minimum detectable activities (MDA) of 5.9 ± 0.4 microcuries (μCi), 19.3 ± 1.1 μCi, 11.7 ± 0.6 μCi, 3.5 ± 0.3 kilograms (kg), and 30.6 ± 1.3 grams (g), respectively. This system proved strong gamma-ray detection capabilities, but was limited in the detection of fissile materials Additional details of this system are presented and advantages of this approach to cargo scanning over current approaches are discussed.
4

Návrh konstrukce rozmetadla tuhých statkových hnojiv / Design of the manure spreader

Pacher, Ján January 2021 (has links)
The diploma thesis deals with the structural design of a solid manure spreader and the subsequent strength control of self-supporting construction. The introduction of the work consists of a research analysis of current design solutions of spreaders on the market with similar parameters as in the assignment. Subsequent chapters deal with the conceptual design of the spreader, preparation of the calculation model, suitable replacement of the components and evaluation of the strength analysis itself. The diploma thesis is accompanied by partial drawing documentation. The work was created in cooperation with ZDT Nové Veselí.
5

Oscillating Heat Spreaders for High Heat Flux Thermal Management

Mahony, Colin Philip 09 December 2016 (has links)
Multiple oscillating heat spreaders (OHS) were fabricated for the purpose of effectively transporting heat fluxes from vehicular electronics. The OHSs possessed modified evaporators for enhanced thermal spreading capabilities; one OHS was designed for pressure shorting, i.e. the ‘Slots OHS’, and the other for thermal shorting, i.e. the ‘Perforated Evaporator OHS’. These OHSs were tested in the axial heating configuration with the evaporator length-wise opposite the condenser, as well as in a centralized heating configuration implemented with the condenser thick-wise opposite the heat source to characterize thermal spreading effectiveness. The condensing location and heat input were varied in the central heating and axial configuration to determine thermal spreading effectiveness dependency to condenser location, heat removal, and heat input. Both OHSs were experimentally compared to an OHS of similar dimensions with no modified evaporator, and the results indicate the modified evaporators improve OHS thermal spreading ability for high heat flux thermal management.
6

Optimization of Heat Spreader

Taposh, Rahat M. 26 July 2012 (has links)
No description available.
7

An Investigation of Chloral Hydrate as an Inhibitor of Bacterial Spreader Colonies in Milk Plate Counts

Gochnour, Runnald Wallace 08 1900 (has links)
This study has consisted primarily of the addition of varying amounts of chloral hydrate to nutrient agar plates and the determination of the definite effects thereof upon the colony plate counts of various samples of milk.
8

Réalisation d'éco-ciments par la valorisation de cendres volantes de charbon non conventionnelles issues de centrales thermiques Spreader Stoker / Realization of eco-cements using non-conventional coal fly ash from spreader stoker thermal power plants

Sow, Moustapha 06 December 2016 (has links)
L'objectif principal de cette thèse a été d'évaluer le potentiel de valorisation des cendres volantes de charbon issues de centrales thermiques Spreader Stoker (Cendres Volantes Spreader Stoker), dans la fabrication d'éco-ciments sur l'île de La Réunion. Nous avons dans un premier temps effectué une caractérisation physico-chimique des CVSS et vérifié leur réactivité. Deux voies de valorisation ont ensuite été retenues, l'une qui ne présente pas de valeur ajoutée mais qui permet de valoriser un volume important de CVSS par une stabilisation dans des matrices à base de ciment, l'autre qui offre une valeur ajoutée aux CVSS par une incorporation dans la fabrication de ciments composés. Le relargage en lixiviation a été étudié pour la première voie de valorisation retenue, puis, les effets des CVSS dans les matrices à base de ciment, notamment le rôle des imbrûlés contenus dans les cendres, ont été évalués aux états frais, durcissant et durci, suivi d'une petite exploitation numérique des données expérimentales. Enfin, une étude de durabilité sur des bétons à base de ciments de laboratoire a été faite par une approche comparative avec la pouzzolane naturelle, qui est actuellement utilisée pour la fabrication de ciments composés sur l'île de la Réunion. / The main objective of this project was to evaluate the potential of coal fly ash from Spreader Stoker thermal power plants (Spreader Stoker Coal Fly Ash) in the manufacture of eco-cements in Reunion Island. We first performed a physico-chemical characterization SSCFA and verified its reactivity. Two valorisation paths were chosen, one of which did not present any added value but which permit to value a large quantity of SSCFA by stabilization in cement-based matrices, the other which offers added value to SSCFA by incorporating it in the manufacture of composed cements. Leachate release was studied for the first path of valorisation, and then the effects of SSCFA in the cement matrices, especially the unburned particles contained in SSFCA, were evaluated in fresh, hardening and hardened states, followed by a small numerical exploitation of the experimental data. Finally, a sustainability study on concretes based on laboratory cements was made using a comparative approach with natural pozzolana, which is currently used for the manufacture of composite cements in Réunion Island.
9

Rozmetací ústrojí rozmetadla / Spreading device of manure spreader

Pikula, Michal January 2008 (has links)
This diploma thesis describes the actual situation of the manure spreader machines of the organic manure and it compares the characteristics of these machines from different manufacturers. And then this thesis designs the driving system for cutter mechanism, for the manure conveyor and the manure spreading device including the details. Drawings are in the attachment.
10

Avaliação objetiva da patência nasal com a utilização de enxertos expansores (spreader grafts) em rinoplastias / Objective evaluation of the nasal patency using spreader grafts in rhinoplasty

Pochat, Victor Diniz de 07 November 2011 (has links)
Introdução: A evolução das técnicas de rinoplastia está intimamente relacionada com o melhor conhecimento anatômico e funcional do nariz. A observação de que a incompetência das válvulas nasais pode ser responsável por até 50 por cento das queixas obstrutivas vem sendo confirmada através de diversos estudos. A utilização de enxertos expansores (spreader grafts) para ampliação das válvulas internas já foi bem estabelecida, no entanto, ainda não foi bem estudada de forma objetiva. Objetivo: A finalidade deste estudo foi avaliar prospectivamente a utilização de enxertos expansores na rinoplastia, fazendo-se uma análise objetiva do grau de melhora da patência nasal dos pacientes através da rinometria acústica e do espelho de Glatzel modificado, bem como uma análise subjetiva da qualidade de respiração dos mesmos pacientes mediante um escore preestabelecido. Metodologia: Foram estudados vinte pacientes submetidos à rinoplastia com utilização de enxertos expansores. Os pacientes foram avaliados no pré-operatório através de análise subjetiva através de questionário de qualidade respiratória - e objetiva, através de medidas da área de secção mínima transversa correspondente à válvula nasal interna mediante a rinometria acústica, e, através do espelho de Glatzel modificado. Após 90 a 120 dias da cirurgia, novas medidas foram realizadas, comparando-as com os resultados obtidos no pré-operatório. Os valores obtidos foram abordados sob a forma de variáveis quantitativas e analisados de acordo com a média e o desvio-padrão pelo teste não paramétrico de Wilcoxon. Conclusão: As medidas referentes às válvulas internas obtidas mediante rinometria acústica foram superiores quando comparados o momento pós-operatório com o pré-operatório dos lados direito e esquerdo. Quando analisados os valores obtidos através do espelho de Glatzel modificado, também observou-se que houve um acréscimo das médias se comparado o pós com o pré-operatório. A análise subjetiva da sensação de patência nasal demonstrou uma melhora na qualidade respiratória e apresentou significância estatística / Background: The evolution of rhinoplasty techniques is closely related to the best knowledge of anatomy and function of the nose. The observation that the nasal valve incompetence may be responsible for up to 50 percent of obstructive symptoms has been confirmed by several studies. Using spreader grafts for internal valves expansion has been well established; however, it has not been well studied objectively. Objective: The purpose of this study was to prospectively evaluate the use of spreader grafts during rhinoplasty. We analyzed objectively the improvement degree in the nasal patency of patients through acoustic rhinometry and modified Glatzels mirror. We also analyzed the subjective improvement degree through a breathing quality score. Method: We studied twenty patients undergoing rhinoplasty with spreader grafts. Patients were evaluated preoperatively through subjective means-by a quality in breathing questionnaire-and objective analysis, by measuring the minimum cross sectional area (corresponding to the internal nasal valve) by acoustic rhinometry and through a modified Glatzels mirror. After 90 to 120 days, new measurements were made and then compared with those obtained preoperatively. The values were addressed in the form of quantitative variables and analyzed according to the mean and standard deviation by the nonparametric Wilcoxon test. Conclusion: The measures relating to the internal valves obtained by acoustic rhinometry were higher when the moment after surgery was compared with the preoperative moment on the left and the right sides. The results obtained by the modified Glatzels mirror also showed an increase in the measures in both sides. Analysis of subjective sensation of nasal patency demonstrated an improvement in quality of breathing with statistical significance

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