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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.
371

Distribution of Windblown Sediment in Small Craters on Mars

January 2011 (has links)
abstract: Many shallow craters near the Spirit Mars Exploration Rover landing site contain asymmetric deposits of windblown sediments which could indicate the predominant local wind direction at the time of deposition or redistribution. Wind tunnel simulations and field studies of terrestrial craters were used to determine trends in deposition as a function of crater morphometry and wind direction. Terrestrial analog field work at the Amboy lava field, Mojave Desert, California, included real-time wind measurements and assessments of active sediment deposition in four small (<100 m) craters. Preliminary results indicate that reverse flow or stagnant wind and deposition on the upwind side of the crater floor occurs in craters with depth-to-diameter (d/D) ratios &ge;0.05. Measurements taken within a crater of d/D of ~0.02 do not indicate reverse flow. Therefore, reverse flow is expected to cease within a d/D range of 0.02 to 0.05, resulting in wind movement directly over the crater floor in the downwind direction with no asymmetric sediment deposition. Wind tunnel simulations using six crater models, including a scaled model of a crater from the Amboy lava field, were completed to assess the wind flow in and around craters as a function of crater morphometry (depth, diameter). Reverse flow occurred in craters with d/D ratios &ge;0.033, resulting in sediment deposition in the upwind portion of the crater floor. Visual observations of a crater with a d/D of ~0.020 did not indicate reverse flow, similar to the results of field studies; therefore, reverse flow appears to cease within a d/D range of 0.020 to 0.033. Craters with asymmetric aeolian deposits near the Mars Spirit landing site have d/D ratios of 0.034 to 0.076, suggesting that reverse flow occurs in these craters. Thus, the position of windblown sediments in the northwest parts of the crater floors would indicate prevailing winds from the northwest to the southeast, consistent with late afternoon winds as predicted by the Mars Regional Atmospheric Modeling System (MRAMS) circulation model. / Dissertation/Thesis / M.S. Geological Sciences 2011
372

Consequences of International Migration on the Size and Composition of Religious Groups in Austria

Potancoková, Michaela, Jurasszovich, Sandra, Goujon, Anne 22 May 2018 (has links) (PDF)
Scientific knowledge on a population's religious composition is essential to understand the challenges faced by societies today. It arises in opposition to speculations about the actual size of religious groups that have been increasingly present in the public discourse in Europe for many years. This is particularly the case in Austria where the flows of refugees and migrants coming from the Middle East and Afghanistan have intensified since 2011 and culminated in 2015. These sparked a debate on the actual size of the Muslim population in Austria. This study fills the gap by presenting estimates of the religious composition for 2016 and projections until 2046 based on several scenarios related to the three major forces affecting the religious composition: migration (including asylum seekers), differential fertility and secularisation. The projections demonstrate that religious diversity is bound to increase, mostly through immigration and fertility. We further focus on the role and implications of international migration on the age and sex composition within the six religious groups: Roman Catholics, Protestants, Orthodox, Muslims, other religions and unaffiliated. We find that the volume and composition of international migrants can maintain youthful age compositions in minority religions - Muslims and Orthodox. Sustained immigration leads to slower ageing but does not stop or reverse the process. The disparity between older majority and younger minority religious groups will further increase the cultural generation gap.
373

Isotopic and elemental determination of lead in particulate matter in the cities of Goiânia (GO) and Rio Claro (SP) using ICP-MS technique / Determinação isotópica e elementar de chumbo em material particulado nas cidades de Goiânia (GO) e Rio Claro (SP) utilizando a técnica ICP-MS

Gemeiner, Hendryk [UNESP] 13 September 2016 (has links)
Submitted by HENDRYK GEMEINER null (h.gemeiner@gmx.net) on 2016-11-11T17:05:34Z No. of bitstreams: 1 tese_mestrado_hendryk_gemeiner.pdf: 13978829 bytes, checksum: 08b385f98431fd9c29309e3aeb7cb1b2 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-11-11T17:52:30Z (GMT) No. of bitstreams: 1 gemeiner_h_me_rcla.pdf: 13978829 bytes, checksum: 08b385f98431fd9c29309e3aeb7cb1b2 (MD5) / Made available in DSpace on 2016-11-11T17:52:30Z (GMT). No. of bitstreams: 1 gemeiner_h_me_rcla.pdf: 13978829 bytes, checksum: 08b385f98431fd9c29309e3aeb7cb1b2 (MD5) Previous issue date: 2016-09-13 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação para o Desenvolvimento da UNESP (FUNDUNESP) / The toxic metal lead (Pb) can be harmful to human health in various manners, but is also considered as a distinguished tracer of environmental pollution, since the relative abundance of its four stable isotopes with the atomic masses of 204, 206, 207 and 208 varies with the emission source. This study is focused on the lead concentrations and isotope ratios in the particulate matter of the Brazilian cities of Goiânia (GO) and Rio Claro (SP), in order to determine the main Pb pollution sources. Particulate matter samples were collected on clean Teflon filters during the rainy and dry season between 2014 and 2016 on the campus of the State University of São Paulo (UNESP) in Rio Claro city and in the centre of Goiânia city near main roads with a high traffic volume. The Pb concentrations as well as the 206Pb/207Pb and 208Pb/207Pb stable isotope ratios of the particulate matter samples were analysed by Inductively-Coupled Plasma Mass Spectrometry. To apply this analytical technique successfully, it was necessary to optimize parameters in case of acquisition time, detector dead time and mass discrimination, which affect the measurement accuracy and precision. Results showed that lead concentrations in Goiânia were different between rainy and dry season. In Goiânia, Pb concentrations showed higher values in dry season than in rainy season, while Pb concentrations were more similar in both sampling periods in Rio Claro. Back trajectories were analysed with the HYSPLIT model to investigate associations between Pb concentration levels and the direction of incoming air masses. However, the comparison of the obtained 206Pb/207Pb and 208Pb/207Pb isotope ratios data with data of potential Pb sources from previous studies indicated that gasoline may be considered as main Pb sources in the particulate matter of Goiânia and Rio Claro. Pb isotope ratios in Goiania were slightly different between dry and rainy season, while in Rio Claro, 206Pb/207Pb isotope ratios showed markedly higher values in dry season than in rainy season. Hence, Pb in Rio Claro in dry season also seems to be influenced by industrial emissions. These assumptions were supported by the calculation of 208Pb/206Pb-207Pb/206Pb diagrams and the contribution factor of Pb coming from gasoline by applying binary mixing equations. / CNPq: 372125/2014-0 / FUNDUNESP: 0050.0092854.14.9
374

Verificação da proporção divina da face em pacientes totalmente dentados

Piccin, Marcia Regina 07 February 1997 (has links)
Orientador: Krunislave Antonio Nobilo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-21T23:45:22Z (GMT). No. of bitstreams: 1 Piccin_MarciaRegina_M.pdf: 1561219 bytes, checksum: a33dc6f96a29dc3881514e9f97cd0e1f (MD5) Previous issue date: 1997 / Resumo: Esta pesquisa foi realizada com a finalidade de verificar a presença da "Proporção Divina" nos segmentos da face, por meio do método fotográfico, em pacientes dentados. A "Proporção Divina" já era utilizada desde a Antiga Grécia por escultores e arquitetos na confecção de suas obras, tendo sido estudada durante o Renascimento. Esta Proporção está presente não apenas nas artes plásticas, como também na natureza. A amostra deste estudo constituiu-se de 121 indivíduos totalmente dentados, de raça branca, de ambos os sexos, cuja faixa etária variou entre 20 e 26 anos de idade. Os pacientes foram posicionados em um cefalostato de Broadbent no qual foram fotografados em norma lateral direita, na posição postural de repouso fisiológico. Sobre as fotografias foram realizadas mensuraçóes de três segmentos da face: A (distância entre os pontos faciais Lc e Sbn ) , B (distância entre os pontos faciais Sbn e St) , C (distância entre os pontos faciais St e Gn), por intermédio de um paquímetro de precisão. Tomando-se por base esses segmentos verificou-se, segundo a análise estatística pelo método de Teste de Hipótese, sua correlação com a "Proporção Divina", obedecendo à razão segundo a qual o segmento maior dividido pelo segmento menor seria igual à soma dos dois, dividido pelo segmento maior, resultando no "número divino" ou "áureo" : 1.618. Também investigou-se a presença da proporção sugerida por Willis (distância entre os pontos faciais Lc e St igual à distância entre os pontos faciais Sbn e Gn). O nível de significância adotado foi de 5%. ...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: The aim of this research project is to verify the presence of the Divine Proportion in the facial parts of dentate patients by means of the photographic method. The Divine Proportion has been used since Ancient Greece by sculptors and architects in the making of their works and was studied during the Renaissance. This proportion is present not only in art but also in nature. The sample group of this study is composed of 121 dentate Caucasians, of both sexes and between 20 and 26 years old. The patients were set in a Broadbent cephalostat in which they were photographed on the right side norm, in resting position. Three facial fraction measurements were taken by means of a precision caliper: A (the distance between facial points Lc and Sbn), B (the distance between facial points Sbn and St), and C (the distance between facial points St and Gn). The presence of the Divine Proportion was ascertained, based on the statistical analysis of these fractions and following the reasoning that the" largest fraction divided by the smallest should be equal to their sum, which, when divided by the largest fraction, results in the Gold Number: 1.618. The presence of the Willis proportion (the distance between facial points Lc and St as equal to the distance between facial points Sbn and Gn) was also investigated. ... Note: The complete abstract is available with the full electronic digital thesis or dissertations / Mestrado / Fisiologia e Biofisica do Sistema Estomatognatico / Mestre em Odontologia
375

A razão áurea e a sequência de Fibonacci / The golden ratio and the Fibonacci sequence

Marcelo Manechine Belini 16 September 2015 (has links)
O presente trabalho irá abordar dois temas matemáticos de diferentes contextos históricos mas que apresentam uma relação intrínseca com o número &Phi;, mais conhecido como número de ouro. Partiremos de uma breve descrição dos conjuntos numéricos N, Z, Q e algumas propriedades dos números racionais para, em seguida, deduzirmos os números irracionais &Pi; e, enfim, os números reais R. Na sequência vamos trabalhar com dois problemas muito antigos: o primeiro aparece na coletânea de livros Os Elementos do matemático grego Euclides, 300 anos a.C., e diz respeito à divisão de um segmento em média e extrema razão e, o segundo, foi publicado no livro Liber Abaci do matemático italiano Leonardo Fibonacci, século XIII, e trata da reprodução de coelhos e a sequência a qual ela origina. Veremos que o número de ouro aparece em ambos os problemas e vem ao longo dos séculos desencadeando muitas teorias que tratam de padrões e beleza. Abordaremos situações do passado e do presente que fazem uso desses padrões, além de fenômenos da natureza. Também apresentaremos um conjunto de atividades para orientar professores do ensino médio de como trabalhar, numa perspectiva interdisciplinar com vários conteúdos da matemática, e o número &Phi;. / This work addresses two mathematical topics from different historical contexts but that have an intrinsic relationship with the number &Phi;, better known as the golden number. We start with a brief description of the numerical sets N, Z, Q and some properties of rational numbers, and then deduct the set of irrational numbers &pi; and, finally, the set of real numbers R. In the sequence we work with two very old problems: the first appears in the collection of books The elements of the Greek mathematician Euclid, 300 years BC, and concerns the division of a segment in extreme and mean ratio, and the second, published in the book Liber Abaci of the Italian mathematician Leonardo Fibonacci, in the thirteenth century, and deals with the breeding of rabbits and the sequence which it originates. We will see that the golden number appears on both problems and has over the centuries triggering many theories dealing with standards and beauty. We discuss situations of past and present that makes use of these standards, as well as natural phenomena. We also present a set of activities to guide middle school teachers on how to work in an interdisciplinary perspective with various mathematical content, and the number &Phi;.
376

The mortality-incidence ratio as an indicator of five-year cancer survival in metropolitan Lima

Stenning Persivale, Karoline Andrea, Savitzky Franco, Maria Jose, Cordero-Morales, Alejandra, Cruzado-Burga, José, Poquioma, Ebert, Díaz Nava, Edgar, Payet, Edouardo 18 January 2018 (has links)
Introduction: The Mortality–Incidence Ratio complement [1 – MIR] is an indicator validated in various populations to estimate five-year cancer survival, but its validity remains unreported in Peru. This study aims to determine if the MIR correlates directly with five-year survival in patients diagnosed with the ten most common types of cancer in metropolitan Lima. Materials and methods: The Metropolitan Lima Cancer Registry (RCLM in Spanish) for 2004–2005 was used to determine the number of new cases and the number of deaths of the following cancers: breast, stomach, prostate, thyroid, lung, colon, cervical, and liver cancers, as well as non-Hodgkin’s lymphoma and leukaemia. To determine the five-year survival, the five-year vital status of cases recorded was verified in the National Registry of Identification and Civil Status (RENIEC in Spanish). A linear regression model was used to assess the correlation between [1 – MIR] and total observed five-year survival for the selected cancers. Results: Observed and estimated five-year survival determined by [1 – MIR] for each neoplasia were thyroid (66.7%, 86.7%), breast (69.6%; 68%), prostate (64.3%, 63.8%) and cervical (50.1%, 58.5%), respectively. Pearson’s r coefficient for the correlation between [MIR – 1] and observed survival was = 0.9839. Using the coefficient of determination, it was found that [1 – MIR] (X) captures the 96.82% of observed survival (Y). Conclusion: The Mortality–Incidence Ratio complement [1 – MIR] is an appropriate tool for approximating observed five-year survival for the ten types of cancers studied. This study demonstrates the validity of this model for predicting five-year survival in cancer patients in metropolitan Lima.
377

Crustal structure of north Peru from analysis of teleseismic receiver functions

Condori, Cristobal, França, George S., Tavera, Hernando J., Albuquerque, Diogo F., Bishop, Brandon T., Beck, Susan L. 07 1900 (has links)
In this study, we present results from teleseismic receiver functions, in order to investigate the crustal thickness and Vp/Vs ratio beneath northern Peru. A total number of 981 receiver functions were analyzed, from data recorded by 28 broadband seismic stations from the Peruvian permanent seismic network, the regional temporary SisNort network and one CTBTO station. The Moho depth and average crustal Vp/Vs ratio were determined at each station using the H-k stacking technique to identify the arrival times of primary P to S conversion and crustal reverberations (PpPms, PpSs + PsPms). The results show that the Moho depth correlates well with the surface topography and varies significantly from west to east, showing a shallow depth of around 25 km near the coast, a maximum depth of 55-60 km beneath the Andean Cordillera, and a depth of 35-40 km further to the east in the Amazonian Basin. The bulk crustal Vp/Vs ratio ranges between 1.60 and 1.88 with the mean of 1.75. Higher values between 1.75 and 1.88 are found beneath the Eastern and Western Cordilleras, consistent with a mafic composition in the lower crust. In contrast values vary from 1.60 to 1.75 in the extreme flanks of the Eastern and Western Cordillera indicating a felsic composition. We find a positive relationship between crustal thickness, Vp/ Vs ratio, the Bouguer anomaly, and topography. These results are consistent with previous studies in other parts of Peru (central and southern regions) and provide the first crustal thickness estimates for the high cordillera in northern Peru.
378

Fractionation of thermomechanical pulp in pressure screening:an experimental study on the classification of fibres with slotted screen plates

Ämmälä, A. (Ari) 01 March 2001 (has links)
Abstract Pressure screening, nowadays the most widely used method for cleaning pulp, has been traditionally investigated as a debris removal process. The aim of this thesis, however, was to study it with a view to the fractionation of pulps, examining systematically and extensively the effects of screening parameters on fractionation under actual working conditions in order to provide an insight into its possibilities and limitations as a fractionation method. The experimental work was performed with a full-scale two-stage pressure screen connected to an industrial TMP process. Fractionation of the pulp was analysed in terms of consistency, freeness, optical fibre length distribution, coarseness index and Bauer-McNett fractions. Two sampling systems were used during the screening experiments, manual and semiautomatic. The latter was assessed to be more reliable, as reflected in lower stochastic variation and the absence of a systematic bias in the mass balance errors over the screen. The poorer reliability of the manual sampling system was offset by the large number of screening tests, however. The results of the screening experiments showed that with a given design of the screen plate, the separation of each fraction was dependent almost exclusively on the mass and volumetric reject rates. The mass flow of fines, defined as the Bauer-McNett P200 fraction, was dependent mostly on the volumetric reject rate, while the mass flow of fibrous fractions (R200, R50, R30, R16) depended mostly on the mass reject rate. The mass reject rate obtained in pressure screening was a result of the choice of operating parameters, but fractionation efficiency could not be affected by using different combinations of these parameters (feed consistency, rotor tip speed and slot velocity) if the mass and volumetric reject rates were kept constant. The slot width together with the contouring of the screen plate affected the fractionation efficiency as compared with the situation at constant mass and volumetric reject rate. Increased fractionation was obtained by reducing the slot width and contouring. The pulp passage ratio, which combines the mass and volumetric reject rates into one parameter, was found to be a expedient way of expressing the fractionation of pulp, as it was possible to present fractionation uniformly as a function of this ratio. The change in freeness was found to correlate quite well with that in Bauer-McNett fractions, and it was a good indicator of fractionation efficiency in screening. Apart from fractionation according to length (or Bauer-McNett fractions), the slotted pressure screen was also found to classify the fibres according to their coarseness. The coarseness difference was partially dependent on the fibre length, but additionally the coarseness in the accept pulp for any given fibre length class was always lower than that in the reject pulp. The difference obtained seemed to depend on the passage ratio of the pulp. This thesis provides new information for the modelling of pulp quality and the design of fractionation experiments, fractionation processes and screen room control strategies.
379

An analysis of value relevance of book value and earnings

Lee, Siu Kuen Raymond 01 January 2001 (has links)
No description available.
380

d-Limonene, a Renewable Component for Polymer Synthesis

Ren, Shanshan January 2017 (has links)
d-Limonene (Lim) was used in various polymer formulations to achieve a more sustainable polymerization. Lim is a renewable and essentially non-toxic compound, derived from citrus fruit peels, that may replace some of the many toxic and fossil-based chemicals used in polymer synthesis. Bulk free-radical polymerizations of n-butyl acrylate (BA) with Lim were performed to investigate Lim co-polymerization kinetics and estimate the monomer reactivity ratios, important parameters in the prediction of copolymer composition. Kinetic modeling of the BA/Lim copolymerization was performed with PREDICI simulation software. The model supports the presence of a significant degradative chain transfer reaction due to Lim. This reaction mechanism is due to the presence of allylic hydrogen in Lim. Nonetheless, relatively high molecular weight polymers were produced. It was concluded that Lim behaves more like a chain transfer agent than a co-monomer. Terpolymerizations of BA, butyl methacrylate (BMA) with Lim were then performed. In order to predict the terpolymer composition, the monomer reactivity ratios for BA/BMA were estimated. By applying the three pairs of co-monomer reactivity ratios to the integrated Mayo-Lewis equation, terpolymer compositions were ably predicted up to high monomer conversion levels. Lim was then used as a chain transfer agent to prepare core-shell latex-based pressure sensitive adhesives (PSA) comprising BA and styrene via seeded semi-batch emulsion polymerization. By varying the concentration of Lim and divinylbenzene crosslinker, the core polymer microstructure was modified to yield different molecular weights and degrees of crosslinking. The core latex was then used as a seed to prepare core-shell latexes. By changing the Lim concentration during the shell-stage polymerization, the molecular weight of shell polymer was also modified. The latexes were characterized for their microstructure and were cast as films for PSA performance evaluation. The PSA performance was shown to be highly related to the polymer microstructure. Tack and peel strength showed a decrease with increasing Lim concentration. Shear strength went through a maximum with a core Lim concentration increase from 0 to 5 phm.

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