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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

The development of methods for the study of properties and performance in fabric for industrial and engineering end-users

Neilly, David G. January 1986 (has links)
This work examines the history of industrial fabrics and investigates how certain of these fabrics have developed to meet the changing demands of their end-uses. It also examines how woven textile fabrics are increasingly competing with the traditional engineering materials as new fibres and filaments allow an ever increasing range of properties; improved fabric engineering techniques are also ensuring that industrial fabrics are more suited to their end-uses. To aid fabric engineering a greater knowledge is required of fabric structure and mechanics, so developments in this field are examined. To help improve fabric research of this type, realistic physical testing methods are required both to test the usefulness of mathematical models, and to simulate conditions experienced in use. Due to certain restrictions of this type of testing, a suitable selective fabric extension measuring device is required so that problem areas such as clamping effects can be avoided. The. lack ofa suitable device to help overcome problems such as this has been a long standing difficulty, so the development of a new fabric extension gauge was one of the main objects of this work. Before such a device could be developed research first involved a survey of many of the previous extension measuring devices, however, as expected nothing suitable emerged. After considering many ideas for possible new devices, it was decided to try and develop a gauge using the relatively new material PVDF piezo polymer film. This is a thin, low modulus film which develops an electrical charge proportional to a CHANGE in mechanical stress, and which can be easily cut to any desired dimensions. Initial attempts to develop a suitable extension measuring device were not completely successful, but when suitable following circuitry was found, and a proper mounting procedure determined, the new gauge appeared very promising. When it was considered that a suitable extension measuring device was available, the next task involved the design of a biaxial tensile and shear testing machine for the new Clothworkers' Textile Hechanics and Structures Laboratory. It was considered that the availability of a suitable selective extension measuring device was of paramount importance before the design of the new tester could be considered. This apparatus was based essentially on, the proven principles of Yendell's and Bassett's testers, but a number of unique features were to be added, such as independently controlled clamps, and the ability to cycle in shear. The principles involved in the design of the mechanical hardware are described, as also are certain original recommendations which have been suggested for the second stage of the project in which the sophisticated control, measurement and analysis techniques will be developed.
2

Využití automatického robotického systému pro povrchovou úpravu materiálů / Use of automated robotic system for surface treatment of materials

PROLL, Jan January 2012 (has links)
In this thesis I deal with the project of a robotic apparatus that could be used for material treatment by using the gliding arc discharge as well as the appropriate design and choice of materials for the atmospheric pressure discharge jet with regards to a possibility of an industrial use. The input and output parameters were studied, such as the air flow regulation with regards to cooling, the design and choice of materials. Then I observed the temperatures near electrodes depending on the air flow. The applicability of the created atmospheric discharge was taken into account.
3

Validação de método de extração supercrítica das sementes do guaraná (Paullinia cupana Kunth, Sapindacese) / Method validation supercritical extraction of guarana seeds (Paullinia cupana Kunth, sapindaceae)

Maul, Aldo Adolar 20 February 2002 (has links)
Em 1947, Messmore, obteve uma patente para a retirada do asfalto de petróleo usando fluidos supercríticos. Depois surgiram muitas patentes, principalmente, sobre a descafeinação do café, a extração do lúpulo e da nicotina. Novo estímulo surgiu com o programa da EPA de redução do uso de produtos químicos até 1995, devido às emissões industriais tóxicas. Estas seriam responsáveis pelo aquecimento global do planeta. Muitos trabalhos publicados até hoje, recomendam o uso do CO2 e o método da extração supercrítica, para a obtenção de extratos naturais. Na área farmacêutica, a validação de processos e metodologia analítica está plenamente aceita como atividade necessária e que tem produzido excelentes resultados na melhoria do desempenho industrial e da qualidade dos produtos. Este trabalho validou o método da extração supercrítica usando as sementes do guaranazeiro, planta que cresce naturalmente na Amazônia. O guaraná, possuidor de cafeína é conhecido como estimulante e regenerador do organismo e entre os índios como afrodisíaco. / Abstract not available.
4

Validação de método de extração supercrítica das sementes do guaraná (Paullinia cupana Kunth, Sapindacese) / Method validation supercritical extraction of guarana seeds (Paullinia cupana Kunth, sapindaceae)

Aldo Adolar Maul 20 February 2002 (has links)
Em 1947, Messmore, obteve uma patente para a retirada do asfalto de petróleo usando fluidos supercríticos. Depois surgiram muitas patentes, principalmente, sobre a descafeinação do café, a extração do lúpulo e da nicotina. Novo estímulo surgiu com o programa da EPA de redução do uso de produtos químicos até 1995, devido às emissões industriais tóxicas. Estas seriam responsáveis pelo aquecimento global do planeta. Muitos trabalhos publicados até hoje, recomendam o uso do CO2 e o método da extração supercrítica, para a obtenção de extratos naturais. Na área farmacêutica, a validação de processos e metodologia analítica está plenamente aceita como atividade necessária e que tem produzido excelentes resultados na melhoria do desempenho industrial e da qualidade dos produtos. Este trabalho validou o método da extração supercrítica usando as sementes do guaranazeiro, planta que cresce naturalmente na Amazônia. O guaraná, possuidor de cafeína é conhecido como estimulante e regenerador do organismo e entre os índios como afrodisíaco. / Abstract not available.

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