• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • 1
  • Tagged with
  • 8
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

The philosophy of epispastics ...

Hopkins, Joel. January 1815 (has links)
Thesis (M.D.)--University of Maryland, 1815. / Microform version available in the Readex Early American Imprints series.
2

A Comparison of Two Methods of Prophylactic Hand Care for Junior High Girls Performing Uneven Bar Skills

Cowan, Robert A. 12 1900 (has links)
The performance of Uneven Parallel Bar skills by junior high girls is hindered by blister formation on the hands. The problem was to investigate certain measures relative to their value in blister prevention.
3

Viabilizacao do reaproveitamento dos blister de PVC/Al e estudos das propriedades do PVC apos processamento por radiacao ionizante / The viability of PVC/Al blister reuse and PVC property studies after ionizing radiation processing

CASTRO, ALEX T.P. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:55:13Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:01Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
4

Post Occupancy Performance Evaluation of "Time of Installation" Factors - A Seven Year Study of SPF Roofing

January 2013 (has links)
abstract: Over the past couple of decades, quality has been an area of increased focus. Multiple models and approaches have been proposed to measure the quality in the construction industry. This paper focuses on determining the quality of one of the types of roofing systems used in the construction industry, i.e. Sprayed Polyurethane Foam Roofs (SPF roofs). Thirty seven urethane coated SPF roofs that were installed in 2005 / 2006 were visually inspected to measure the percentage of blisters and repairs three times over a period of 4 year, 6 year and 7 year marks. A repairing criteria was established after a 6 year mark based on the data that were reported to contractors as vulnerable roofs. Furthermore, the relation between four possible contributing time of installation factors i.e. contractor, demographics, season, and difficulty (number of penetrations and size of the roof in square feet) that could affect the quality of the roof was determined. Demographics and difficulty did not affect the quality of the roofs whereas the contractor and the season when the roof was installed did affect the quality of the roofs. / Dissertation/Thesis / M.S. Construction 2013
5

Viabilizacao do reaproveitamento dos blister de PVC/Al e estudos das propriedades do PVC apos processamento por radiacao ionizante / The viability of PVC/Al blister reuse and PVC property studies after ionizing radiation processing

CASTRO, ALEX T.P. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:55:13Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:01Z (GMT). No. of bitstreams: 0 / O objetivo deste trabalho foi o de separar através de um processo de dissolução, o PVC e o alumínio, que são componentes das embalagens tipo blister, comumente encontradas como embalagens de remédios. Foi estudado, também o efeito da radiação ionizante sobre o PVC e por ultimo a reciclagem mecânica do PVC separado por um processo de extrusão. O material utilizado neste trabalho foi oriundo de sobras da industria farmacêutica, sendo este em forma de embalagens com defeito ou rebarbas de produção.Após a moagem do material, realizada para facilitar o manuseio e a homogeneização do sistema, foram escolhidas duas bases para realizar a dissolução do alumínio: hidróxido de sódio e hidróxido de potássio. Foi utilizado um sistema com duas concentrações (1 e 2M), as duas bases, e se o sistema teria ou não agitação. Este método limitou em oito os experimentos. Após a dissolução, amostras do material foram submetidas a radiação ionizante, realizada com doses de 50, 100, 150 e 200kGy no acelerador de elétrons modelo Dynamitron II do CTR-IPEN/CNEN-SP. Estas amostras foram submetidas a seguir, a um ensaio de resistência à tração para a analise das modificações causadas pela irradiação. A última etapa do trabalho foi a reciclagem mecânica do PVC já separado do alumínio. A reciclagem foi realizada em equipamento industrial, uma extrusora de tubos de PVC. O material foi aditivado em um misturador intensivo com lubrificantes, estabilizantes térmicos carga e pigmento, e em seguida processado na forma de eletrodutos de PVC rígido.Após os oito experimentos, o sistema com a base hidróxido de potássio concentração 2M e agitação, foi o que apresentou a melhor relação entre tempo de dissolução e característica do material resultante, não ocorrendo degradação no PVC. Nas amostras irradiadas, a coloração do material foi modificada assim como o seu alongamento que foi maior quanto maior a dose de irradiação recebidas, indicando a cisão das cadeias de PVC. A extrusão do PVC foi realizada com sucesso, conseguindo-se transformar aproximadamente 200kg de PVC, devidamente aditivado, demonstrando assim a viabilidade de todo o trabalho. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
6

Influence of the Particle Flux on Surface Modifications of Tungsten / Influence du flux de particules sur les modifications de surface du tungstène

Buzi, Luxherta 23 October 2015 (has links)
Le tungstène est le matériau choisi pour le divertor d'ITER en raison de ses propriétés thermiques et physiques. Les densités de flux et les énergies des particules, et la température de surface pourront varier de plusieurs ordres de grandeur le long de la surface du divertor, soit respectivement 1020-1024 m2s-1, 0.1-100 eV, et 370-1370K. Exposé à de telles conditions, le tungstène peut subir de l'érosion, des fissurations et d'autres modifications de surface affectant ses propriétés thermomécaniques. Une autre préoccupation est la rétention des atomes de tritium implantés dans la surface et leur diffusion dans l'épaisseur du matériau. Nombre d'études ont porté sur la rétention et les modifications de surface induite par le plasma, mais se concentraient principalement sur l'effet de l'énergie des ions, leur fluence et la température de surface, mais très peu portaient sur l'influence du flux de plasma, avec des résultats erratiques et peu cohérents entre eux. L'objectif de cette thèse est de fournir une image cohérente du comportement du tungstène exposé à des conditions pertinentes pour les futurs réacteurs de fusion. Une investigation systématique évaluant l'impact de la densité de flux de plasma et de la température de l'exposition sur les modifications de surface et l'accumulation d'hydrogène dans tungstène a été effectuée au moyen d'expériences menées dans les dispositifs plasma linéaires, PSI-2 à Jülich, Pilot-PSI et Magnum-PSI à DIFFER, et PISCES-A à UCSD. La corrélation entre densité de flux de particules, température d'exposition, modifications de surface et rétention de l'hydrogène dans le tungstène a été étudiée pour différentes microstructures de matériau. Des échantillons de trois types de tungstène poly-cristallin (traité thermiquement à 1273 et 2273 K) et monocristallin (orientation 110) ont été exposés à des plasmas de deutérium et des températures de surface de 530 à 1170 K à deux gammes différentes de flux d'ions deutérium (~1022 et ~1024 m2s-1). Toutes les expositions ont été effectuées à la même énergie d'ions incidents de 40 eV et une fluence de particules de 1026 m2. Les échantillons ont été analysés post mortem en utilisant diverses techniques d'imagerie et d'analyse de surface (microscopie, spectroscopie de désorption thermique (TDS) et analyse par faisceau d'ions). L'augmentation du flux de particules de deux ordres de grandeur a provoqué la formation de bulles au-dessus de 700 K, températures pour lesquelles elles sont généralement absentes à faible flux. De petites cloques de respectivement quelques dizaines de nm et jusqu'à une taille latérale de 1 micron ont été détectées sur des échantillons de tungstène poly-cristallin recuit et monocristallin. Au contraire, les cloques sont absentes sur les échantillons recristallisés, sauf à faible flux et basse température où des vésicules d'environ 10 micron et des cavités sont apparues le long des joints de grains. La rétention totale de deutérium a été mesurée par TDS. A faible température d'exposition la fraction retenue était un à deux ordres de grandeur plus élevée après l'exposition à faible flux qu'à haut flux. Au contraire, une tendance opposée de la rétention totale à des températures d'exposition élevées a été observée. Par conséquent, le maximum de la rétention de deutérium totale a été observé pour une température supérieure dans le cas du flux incident de particules élevée (~850 K) comparée à l'exposition de faible flux (~650 K). Globalement les résultats sur la rétention de deutérium étaient similaires pour toutes les microstructures de tungstène étudiées. La rétention diminue à haute température et son maximum est plus bas pour des expositions à haut flux. Or, en raison du décalage de la rétention maximale vers des températures plus élevées, la quantité de deutérium piégée pour des températures supérieures à 800 K était plus élevée à haut flux qu'à faible flux, soit ~ un ordre de grandeur inférieur à la rétention maximum à faible flux / Tungsten is the selected material to be used in the ITER divertor due to its favorable thermal and physical properties. Particle flux densities and energies, and surface temperature will vary by several orders of magnitude along the divertor surface, with values in the range 1020-1024 m2s-1, 0.1-100 eV and 370-1370 K, respectively. Exposed to such conditions, tungsten may undergo erosion, cracking and other surface modifications affecting its thermal and mechanical properties. Another concern is the retention of implanted radioactive fuel atoms (tritium) in the material surface and their diffusion through the bulk. A considerable amount of studies have addressed retention and plasma induced surface modifications, focusing mainly on the effect of ion energy, ion fluence and surface temperature while very little knowledge exists on the influence of the plasma flux. These results are largely scattered and occasionally bear a lack of consistency. The aim of this thesis is to provide a coherent picture of the behavior of tungsten exposed to plasma conditions relevant for future fusion reactors. A systematic investigation assessing the impact of the plasma flux density and exposure temperature on surface modifications and hydrogen accumulation in tungsten was performed by means of experiments carried out in the linear plasma devices PSI2 at Forschungszentrum Juelich, Pilot-PSI and Magnum-PSI at DIFFER, and PISCES-A at UCSD. The correlation between the particle flux density, exposure temperature, surface modifications and hydrogen retention in tungsten was investigated for different material microstructures. Three types of polycrystalline tungsten (thermally treated at 1273 and 2273 K) and single crystal tungsten samples (110 crystal orientation) were exposed to deuterium plasmas at surface temperatures of 530-1170 K to two different ranges of deuterium ion fluxes (low and high flux: ~1022 and ~1024 m2s-1). All the exposures were performed at the same incident ion energy of 40 eV and particle fluence of ~1026 m2. The exposed samples were analyzed postmortem utilizing various surface imaging and analyses techniques (microscopy, thermal desorption spectroscopy and ion beam analysis). Increasing the particle flux by two orders of magnitude caused blister formation at temperatures above 700 K for which blistering is usually absent under low flux exposure conditions. Small blisters of several tens of nanometers and up to 1 micrometer of lateral size were detected on the annealed polycrystalline and in single crystal tungsten samples, respectively. On the contrary, blisters were absent on the recrystallized samples except for the low flux and low temperature case where large blisters of about 10 micrometer and cavities along the grain boundaries appeared. The total deuterium retention was measured by means of thermal desorption spectroscopy (TDS). In the cases with low exposure temperatures, the retained fraction of deuterium was one to two orders of magnitude higher after exposure to the low flux compared to the high flux. On the contrary, an opposite tendency of the total deuterium retention at high exposure temperatures was observed. Hence, the maximum of the total deuterium retention was observed to occur at a higher temperature in the case of high incident particle flux (~850 K) compared to low flux exposures (~650 K). Overall, experimental results on deuterium retention were similar for all the investigated tungsten microstructures. Deuterium retention decreased at high temperatures and the maximal retention was lower for high flux exposures. However, due to the shift of the maximal retention to higher temperatures, the amount of deuterium retained at temperatures above 800 K was higher at high flux rather than at low flux, being still about one order of magnitude lower than the maximal retention at low flux
7

Design of microfluidic multiplex cartridge for point of care diagnostics

Ereku, Luck Tosan January 2017 (has links)
A simple, but innovative microfluidic Lab-on-a-chip (LOC) device which is broadly applicable in point of care diagnostics of biological pathogens was designed, fabricated and assembled utilising explicit microfluidic techniques. The purpose of this design was to develop a cartridge with the capability to perform multiplex DNA amplification reactions on a single device. To achieve this outcome, conventional laboratory protocols for sample preparation; involving DNA extraction, purification and elution were miniaturized to suit this lab-on-a-chip device of 75mm X 50mm cross-sectional area. The extraction process was carried out in a uniquely designed microchamber embedded with chitosan membrane that binds DNA at pH 5.0 and elutes when a different solution at pH 9.0 flows through. Likewise, purification protocol that occurs in the designed waste reservoir is very significant in biomedical field because it is concerned with waste treatment and cartridge disposability, was performed with a super absorbent powder that converts liquid to a gel like substance. This powder is known as sodium polyacrylate, which is also they treated with anti-bacterial chemicals to prevent environmental contamination. Furthermore, this process also employed the use of a passive valve for a precise fluid handling operation involving flow regulation from extraction to waste reservoir. In order to achieve the intended multiplexing function a multiplexer was created to distribute flow simultaneously through a bifurcated network of channels connected to six similar amplification microchambers. Prior to fabrication, computational fluid dynamics (CFD) simulation was utilized at flowrates less than 10μL/s as the means to test the effectiveness of each design components and also to specifically deduct empirical values that can be analyzed to improve or understand the relationship between the fluid and geometrical constraints of the microfluidic modular elements. The device produced was a hybrid cartridge composed of PDMS and glass which is the most widely used materials microfluidics research due to their low cost and simplicity of fabrication by soft lithography technique. The choice of material also took into account the various physical and chemical properties advantages and disadvantages in their bio-medical applications. Such properties include but not limited to surface energy that determines the wetting fluid characteristics, biocompatibility, optical transparency. Subsequently, after a prototype cartridge was developed fluid flow experimentation using liquid coloured dye was used on the fully fabricated cartridge to test the efficacy of its microfluidic functionalities before expensive DNA amplification reagents were utilised at similar flowrates to the CFD simulations. This gave rise to comparison between similar and dissimilar flow Peculiarities in the microfluidic circuit of both experiments. The final experiment was performed with the aid of a recent molecular technique in DNA amplification known as of RPA kit (recombinase polymerase amplification reaction). It involved performing two main reaction experiments; first, was the positive experiment that bears the sample DNA and the latter, negative that served as the control without DNA. In the end, quantitative analysis of results was done using an agarose gel that showed 143 base pairs, for the positive samples, thus validating the amplification experiment.
8

[pt] CARACTERIZAÇÃO FÍSICO-QUÍMICA DE FILMES POLIMÉRICOS MULTICAMADAS PARA AVALIAÇÃO DE EMBALAGENS FARMACÊUTICAS / [en] PHYSICOCHEMICAL CHARACTERIZATION OF MULTILAYER POLYMER FILMS FOR EVALUATION OF PHARMACEUTICAL PACKAGING

LIVIA LINHARES MARQUES ALVES 08 April 2020 (has links)
[pt] As embalagens de medicamentos acondicionam e protegem os fármacos, sendo que alterações nos materiais de embalagem têm impacto crítico no desempenho do produto. Os blisters, que consistem de um tipo de embalagem primária de filmes poliméricos, entram em contato direto com o medicamento. A caracterização dos materiais de embalagens primárias é o principal meio de garantir a adequação dos mesmos ao uso pretendido. Reconhecendo essa necessidade, a nova farmacopeia dos Estados Unidos, que entrará em vigor em 2020, amplia suas considerações para caracterização de embalagens. Contudo, o novo documento ainda apresenta limitações de abrangência das recomendações técnicas e não considera filmes multicamadas, os quais são amplamente utilizados na indústria. No presente trabalho, cinco tipos de filmes para embalagem foram caracterizados por meio da Calorimetria Exploratória Diferencial e Espectroscopia no Infravermelho, ambas mencionadas nas farmacopeias; e também, para determinar os limites térmicos dos materiais avaliados, pela Análise Termogravimétrica. Com a inexistência de referências para filmes em multicamadas, os resultados foram comparados com divergentes valores publicados na literatura. Identificou-se, nos cinco materiais analisados, a existência de um plastificante não informado pelos fabricantes. O estudo realizado confirma a importância da caracterização dos blisters, apontando para a necessidade tanto da ampliação das recomendações da farmacopeia para inclusão de novos materiais e filmes multicamadas, quanto da produção de materiais de referência para os polímeros empregados nas embalagens. / [en] Pharmaceutical packaging wraps and protects drugs, and changes in packaging materials have a critical impact on product performance. Blisters, which consist of one type of primary packaging of polymer films, come into direct contact with the drug. The characterization of the primary packaging materials is an essential strategy for ensuring that they are suitable for the intended use. Recognizing this need, the new United States Pharmacopeia, which will come into effect in 2020, expands its considerations for characterization of packaging. However, the new document still contains limitations on the scope of the technical recommendations and does not consider multilayer films, which are widely used in industries. In the present work, five types of packaging films were characterized by Differential Scanning Calorimetry and Infrared Spectroscopy, both mentioned in the pharmacopeias; and also, to determine the thermal limits of the evaluated materials, by the Thermogravimetric Analysis. With the lack of references for multilayer films, the results were compared with divergent values published in the literature. It was identified, in the five materials analyzed, the existence of a plasticizer not identified by the manufacturers. This study confirms the importance of the characterization of the blisters, pointing to the need to not only expand the recommendations of the pharmacopeia, but also to include new materials and multilayer films, and the production of reference material for the polymers used in packages.

Page generated in 0.0691 seconds