Thesis (Ph.D.)--McMaster University, 2004. / Supervisor: D.S. Wilkinson. Includes bibliographical references (leaves 164-170). Also available via World Wide Web.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xvi, 180 p.; also includes graphics (some col.). Includes bibliographical references (p. 168-180). Available online via OhioLINK's ETD Center

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Orientador: Cecília Amélia de Carvalho Zavaglia / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T19:00:55Z (GMT). No. of bitstreams: 1 Brito_JuniaRibeirode_M.pdf: 3348250 bytes, checksum: 88bd87279275d739ae30a9b4306d65de (MD5) Previous issue date: 2003 / Resumo: A resina composta fotopolimerizável é amplamente utilizada como material dental restaurador tanto em dentes anteriores como em dentes posteriores. Porém, como todo material polimérico, a resina composta também sofre contração devido a sua reação de polimerização. A contração de polimerização das resinas compostas dentais tem sido relatada como causa das falhas na interface dente-restauração, resultando em microinfiltrações de bactérias, com conseqüências negativas para o dente restaurado. O objetivo deste estudo é analisar a contração linear de polimerização de duas resinas compostas fotopolimerizáveis, uma experimental e outra comercial. A experimental foi desenvolvida por Palácio (2003) no DEMA/FEM/UNICAMP. A resina composta comercial é a Z-250/3M. A mudança dimensional que ocorreu durante e após a fotopolimerização foi monitorada durante 5 minutos a partir do instante em que a luz foi ligada. Na metodologia utilizada, os valores da contração linear de polimerização das referidas resinas compostas foram quantificados através da utilização de extensômetros elétricos / Abstract: The composite resin is widely used as a material for the restoration of anterior and posterior teeth. However, like any other polymeric material, the composite resin also presents shrinkage due to it's polymerization reaction. The polymerization shrinkage of dental composite resins has been reported to cause a marginal gap between the cavity wall and the restoration, resulting in bacterial microleakage, with negative consequence for the tooth. The main goal of this study is to analyse the linear shrinkage of two photo-activated dental composite resins. An experimental one, developed by Palacio (2003), and other commercial (Z-250/3M). The measuring time of linear shrinkage was 5 minutes from the start of photoactivation. The dimensional changes which develop during and after the curing of composite resins, were measured by electrical resistance strain gages / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

The Florida Technological University four-component strain-gage balance is an internally mounted, half-inch diameter balance capable of measuring four components of load: front and rear normal force, axial force, and rolling moment. Measurement of these components is accomplished by means of sixteen strain gages that are mounted on the balance and wired into four full bridge circuits. When the balance is subjected to a load, the strain gages, through a small resistance change, indicated the strain a balance element is undergoing. This report presents a description of the balance and its support equipment, and outlines specific calibration procedures necessary to their successful implementation. These calibration procedures take two forms: that of calibrating the readout equipment, and that of calibrating the balance itself. Also contained in this report is a method of reducing calibration data into a set of parameters applicable to the balance. To aid in the calibration of the balance, a calibration assembly was designed and built. Two calibration models were designed to facilitate the incremental loading of the balance and the interpretation of the readout data.

Modern engineering structures often incorporate new materials and complex designs for which existing techniques for nondestructive evaluation prove inadequate, especially for dynamic and in-service measurements. At the same time, optical fiber sensors have been identified as an ideal candidate for embedded and attached measurements of material parameters such as strain, temperature, or state of damage. In particular, sensors based on optical fiber modal interference phenomena have been shown to be capable of highly sensitive detection of static and dynamic strain. This work reviews known applications of modal domain sensing to measurement science to date, and discusses the principles behind the method. A general expression for the intensity distribution emerging from a multimode fiber is formulated, covering both few mode and highly multimode fibers, and new expressions for their sensitivity to both radial and axial strain are derived. Optimized multimode fibers are seen to show an intrinsic phase sensitivity which rivals or even surpasses that of the single mode interferometer, especially in the case of applied radial strain. The use of modal domain sensors for real-time ultrasonic wave transduction is described as a particular application to NDE, with experimental results being presented with regard to acoustic emission monitoring as well as the detection and analysis of shock waves due to impact. Finally, optimization schemes and alternatives for such sensors are addressed, and recommendations for future work are raised. / Ph. D.

Asphalt cement content is one of the most important requirements for producing high quality hot-mix asphalt. The determination of the asphalt cement content of hot-mix asphalt by traditional methods is time consuming and hazardous. A demand for faster and safer methodes) led to the development of a nondestructive technique using nuclear technology. Measuring asphalt cement content of Marshall specimens by nuclear gauges is a new technique; this study evaluates the feasibility of using the nuclear gauges. Two hundred fifty-six specimens were prepared for this purpose. The study evaluated the effect of different parameters on the measured asphalt cement content by 3241-C Troxler nuclear asphalt content gauge. The following parameters were considered: aggregate type, aggregate gradation, air-void content, moisture content in specimens, asphalt cement content, and total specimen weight. Different calibration models were developed for different bituminous mixtures. / Master of Science

This work reports the convection calibration of Schmidt-Boelter heat flux gages in shear and stagnation air flow. The gages were provided by Sandia National Laboratories and included two one-inch diameter and two one-and-one-half-inch diameter Schmidt-Boelter heat flux gages. In order to calibrate the sensors a convection calibration facility has been designed, including a shear test stand, a stagnation test stand, an air heater and a data acquisition system. The current physical model for a combined radiation and convection heat transfer environment uses an additional thermal resistance around the heat flux gage. This model clearly predicts a non-linear dependency of the gage sensitivity over a range of heat transfer coefficients. A major scope of this work was to experimentally verify the relation found by the model assumptions. Since the actual heat sink temperature is not known and cannot be measured, three different cases have been examined resulting in three different sensitivities for one pressure value, which is the gage sensitivity for the not cooled case and the gage sensitivity for the cooled case, based on the plate temperature or on the cooling water temperature. All of the measured sensitivities for shear as well as for stagnation flow fit well in the theory and show the non-linear decay for increasing heat transfer coefficient values. However, the obtained data shows an offset in the intersection with the sensitivity at zero heat transfer coefficient. This offset might arise from different radiation calibration techniques and different surface coatings of test gage and reference standard. / Master of Science