Thesis (M.S.)--University of Michigan, Ann Arbor, 1974. / Typescript (photocopy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 30-31).

The main text of the thesis consists of seven chapters. Following the literature survey, the work in Chapter 2 focuses on the study of the whole process of pressure die casting. The necessity of reclassification against the traditional 'three-stage' description is introduced in order to build a new basic tenet in constructing theoretical and practical investigations, which leads to the creation of fluid dynamic mathematical models of the process. On the basis of Chapter 2, Chapter 3 concentrates on dealing with the computer simulation of filling flow patterns occurring in the third stage that play the most important role in the process. The Simplified Marker And Cell (SMAC) method is used to obtain the computational results of the filling patterns of pressure die casting processes. On the basis of the computational analysis of typical examples, the viscosity, gravitational force and velocity effects on the overall filling pattern are examined, that lead to a validation of the important hypothesis that an ideal liquid can be used in numerical simulation of filling patterns and this enables one to achieve a more effective computer program for a complex cavity by quasi-3D or 3D models. Chapter 4 treats a specific problem of the residual flow that exists in the final (fifth) stage of the process. Mathematical models of residual flow are derived. Chapter 5 mainly consists of two parts. The first part deals with the application of similitude laws for simulating flows in pressure die casting processes. Detailed analyses and criteria on different relationships between model and prototype are given in order to correct previously offered formulae by Eckert (1989). The results of numerical simulation presented in Chapter 3 are also extended to validate the similitude criteria. The second part of Chapter 5 presents the use of a charge coupled device(CCD) for studying the diversity of fluid motion including the filling pattern, residual flow, thermals and air entrapment during cavity-fill and post cavity-fill within a one single shot cavity filling in water analogue experiments. A discussion, conclusions and suggestions for further study of the subject concerned are presented in Chapters 6 and Chapter 7.

Population grow in recent years requires an extension of the current pipeline sanitary system. For this purpose, granular excavation and landfill works are associated with pedestrian traffic congestion. Therefore, it is necessary to develop an innovative and sustainable alternative to reduce the problems generated during the execution of the conventional process. This research proposes the use of flowable fill due to the multiple advantages offered by this material. On the one hand, it is economical for medium to large trench fill volumes, considering savings in labor (it is done with a small number of workers), in equipment (does not require the rental or purchase of compaction equipment) and in time (the pouring is done by directly pumping the mixture, from the mixing machines to the excavation). On the other hand, being self-compacting and self-leveling decreases the width of the trenches, reducing excavation and filling volumes; which, in turn, incur money savings. Also, this material guarantees work safety, since people are not required inside the excavation and fill in poorly accessible areas without any problem. Dosages were established for ten flowable fill mixtures with cement contents of 50, 60, 70, 80 and 90 kg of cement and a range of admixture from 1.75 to 2.00%; The results indicated that decreasing the fine aggregate - coarse aggregate ratio, the compressive strength of the mixtures increases and the slumps of the mixtures decreases, and the compressive strength increases directly proportional to the cement content.

Since the failure of the Scan Line Corrector (SLC) instrument on Landsat 7, observable gaps occur in the acquired Landsat 7 imagery, impacting the spatial continuity of observed imagery. Due to the highly geometric and radiometric accuracy provided by Landsat 7, a number of approaches have been proposed to fill the gaps. However, all proposed approaches have evident constraints for universal application. The main issues in gap-filling are an inability to describe the continuity features such as meandering streams or roads, or maintaining the shape of small objects when filling gaps in heterogeneous areas. The aim of the study is to validate the feasibility of using the Direct Sampling multiple-point geostatistical method, which has been shown to reconstruct complicated geological structures satisfactorily, to fill Landsat 7 gaps. The Direct Sampling method uses a conditional stochastic resampling of known locations within a target image to fill gaps and can generate multiple reconstructions for one simulation case. The Direct Sampling method was examined across a range of land cover types including deserts, sparse rural areas, dense farmlands, urban areas, braided rivers and coastal areas to demonstrate its capacity to recover gaps accurately for various land cover types. The prediction accuracy of the Direct Sampling method was also compared with other gap-filling approaches, which have been previously demonstrated to offer satisfactory results, under both homogeneous area and heterogeneous area situations. Studies have shown that the Direct Sampling method provides sufficiently accurate prediction results for a variety of land cover types from homogeneous areas to heterogeneous land cover types. Likewise, it exhibits superior performances when used to fill gaps in heterogeneous land cover types without input image or with an input image that is temporally far from the target image in comparison with other gap-filling approaches.

No description available.

No / A computer simulation based on a Monte-Carlo technique has been developed and used to investigate the influence of pellet size, dispersity, shape and aggregation on the filling of hard shell capsules. The simulations are in general agreement with experimental observations previously reported. The results also confirm recent findings that filling is a function of pellet shape and that above an aspect ratio value of 1.2 filling reproducibility is reduced. The methodology is simple and rapid in execution allowing many computer-based experiments to be performed with minimum effort.

This dissertation is an investigation into the classification of all hyperbolic manifolds which admit a reducible Dehn filling and a toroidal Dehn filling with distance 3. The first example was given by Boyer and Zhang. They used the Whitehead link. Eudave-Muñoz and Wu gave an infinite family of such hyperbolic manifolds using tangle arguments. I show in this dissertation that these are the only hyperbolic manifolds admitting a reducible Dehn filling and a toroidal Dehn filling with distance 3. The main tool to prove this is to use the intersection graphs on surfaces introduced and developed by Gordon and Luecke. / text

Made available in DSpace on 2017-07-24T19:22:25Z (GMT). No. of bitstreams: 1 Carlos Antonio Pellissari.pdf: 1778484 bytes, checksum: 53efb541915c3a7f2e9f0a102717239b (MD5) Previous issue date: 2004-07-21 / Although reaching high success rates there is a great number of root canals endodontically treated which don’t reach the wished results. In these cases there is necessity to indicate the periapical surgery. Among the surgical kinds the most used is the conventional retrograde filling. This surgical modality has also impelled the main researches about the matter.The present study had the purpose to evaluate “in vitro”the microleakage when were used some retrofilling materials and also the influence of application of EDTA in the retrograde cavity before to be filled the canals. They were used in this study seventy two mandibular and maxillary human canine teeth extracted for several reasons in Surgical Clinic of State University – Ponta Grossa – Pr – Brazil. Initially all teeth were instrumented and filled according to traditional technics of preparation and filling. After this the teeth had the apical portion sectioned perpendicularly to tooth long axis and its external surface was made waterproof. After the apicectomy they were prepared cavities of approximately 3 mm deep using the sonic equipment GNATUS ( JET- SONIC FOUR) with the point S12 with the angle of 90 with the active point with diamond with 3 mm long and a caliber compatible to the most of teeth. The seventy two teeth were fortuitously distributed in six groups with twelve teeth each one according to the materials to be used. In three groups before the retrograde filling it was made an application of EDTA during 3 minutes in retrograde cavity. According to the procedures and the materials used in retrofillings the six groups were so constituted: Group I – retrofilling with Sealapex+zinc oxide eugenol; Group II – retrofilling with IRM; Group III – retrofilling with MTA; Group IV – application of EDTA and retrofilling with Sealapex+zinc oxide eugenol; Group V – application of EDTA and retrofilling with IRM; Group VI – application of EDTA and retrofilling with MTA. After the operative procedures and drying of the roots these were imersed in 2 methilene solution during sixty hours at 37C. After this period the roots were washed in current water during 12 hours and the proofing layer was removed. It was performed them the longitudinal wearing of the root till the exposition of the retrofilling material making possible the analysis of the leakage. To verify the extension of the leakage the teeth were photographed with digital camera and the images transported to the computer where they were analysed in a specific program called Mocha to measure the apical microleakage. The leakage was measured from a root end to the more depth of leakage observed. The values of the leakages of each tooth in milimeters and the overages of the leakages were duly ordered and submited to the statistical analysis from which we conclude: There wasn’t influence when it was applicated the EDTA in retrograde cavity before the use of the retrofilling materials evaluated; There are statistically significative differences when the groups of retrofilling materials were compared and when the application of EDTA alone was analysed; The retrofilling material IRM presents the most degree of marginal leakage; MTA was shown to be the best among the evaluated materials; Sealapex+zinc oxide eugenol didn’t present significative difference in relation to MTA; EDTA used in retrograde cavity increased the degree of microleakage. / Embora atingindo altos índices de sucesso, há um grande número de canais radiculares, tratados endodonticamente, que não atingem os resultados desejados.Nesses casos há a necessidade da indicação da cirurgia parendodôntica. Dentre as modalidades cirúrgicas a mais empregada ainda é a obturação retrógrada convencional. Essa modalidade cirúrgica tem motivado também a maioria das pesquisas. O presente trabalho teve como objetivo a análise “in vitro”da microinfiltração, quando se utilizaram alguns materiais retrobturadores e também a influência da aplicação de EDTA na cavidade retrógrada, antes de serem retrobturados os canais. Foram utilizados no presente trabalho 72 dentes caninos humanos superiores e inferiores permanentes, extraídos por diversos motivos, na Clínica de Cirurgia da Universidade Estadual de Ponta Grossa. Inicialmente todos os dentes foram instrumentados e obturados, segundo técnicas tradicionais de preparo e obturação. Após isso os dentes tiveram a porção apical seccionada perpendicularmente em relação ao longo eixo do dente e sua superfície externa impermeabilizada. Após a apicectomia foram confeccionadas cavidades de aproximadamente 3 mm de profundidade, utilizando-se o aparelho de ultra-som Gnatus (Jet – Sonic Four) com a ponta S12, com ângulo de 90, com ponta ativa diamantada com 3 mm de comprimento e um calibre que se aplica à maioria dos canais. Os 72 dentes foram então distribuídos aleatoriamente em 6 grupos experimentais com 12 dentes cada um, segundo os materiais a serem utilizados. Em 3 grupos, antes da obturação retrógrada, foi feita a aplicação de EDTA, por 3 minutos, na cavidade retrógrada. De acordo com os procedimentos e materiais utilizados na retrobturação, os 6 grupos experimentais foram assim constituídos: Grupo I – Retrobturação com Sealapex + óxido de zinco e eugenol; Grupo II – Retrobturação com IRM; Grupo III – Retrobturação com MTA; Grupo IV – Aplicação de EDTA e retrobturação com Sealapex+óxido de zinco e eugenol; Grupo V – Aplicação de EDTA e retrobturação com IRM; Grupo VI – Aplicação de EDTA e retrobturação com MTA. Após a realização dos procedimentos operatórios e a secagem das raízes, essas foram imersas em solução de azul de metileno a 2%,por 60 horas a 37C.Decorrido esse período as raízes foram lavadas durante 12 horas em água corrente e a camada impermeabilizante removida. Realizou-se então o desgaste longitudinal da raiz no sentido vestíbulo-lingual até a exposição do material retrobturador, possibilitando assim a análise da infiltração do corante. Para verificação da extensão da penetração da solução corante os dentes foram fotografados com uma câmara fotográfica digital e as imagens levadas ao computador, onde foram analisadas em um programa específico chamado Mocha, para medir a microinfiltração apical. A infiltração foi medida a partir do extremo apical radicular, até a maior profundidade de infiltração observada. Os valores em milímetros das infiltrações de cada dente e as médias das infiltrações foram devidademente tabulados e submetidos à análise estatística, levando-nos às seguintes conclusões: Não houve influência da aplicação do EDTA na cavidade, antes do uso dos materiais retrobturadores avaliados; Existem diferenças estatisticamente significantes, quando comparados os grupos de materiais retrobturadores e quando analisada a aplicação do EDTA isoladamente; O material retrobturador IRM apresenta o maior grau de infiltração marginal; O MTA mostrou-se ser o melhor entre os materiais avaliados; O Sealapex+Óxido de zinco e eugenol não apresentou diferença significativa em relação ao MTA; O EDTA, utilizado na cavidade retrógrada, provocou um aumento no grau de infiltração.

This thesis describes the structural design of automatic stoking conveyor to log into the boiler during operation. The work described in the first part of the current methods of burning logs of wood, the combustion process and the possibility of smoke detecting. The second part focuses on the structural design of the device and a description of the implementation of functional sample.

International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Fast Fourier Transform (FFT) converts digitally sampled time domain data into the frequency domain. This paper will provide an advanced introduction for the telemetry engineer to basic FFT theory and then present and explain the different user preprocessing options that are available when using the FFT. These options include: using windowing functions, “zero filling” for frequency data interpolation, and setting the frequency resolution of the FFT resultant spectrum,