level, the standard error of the intercept is underestimated whereas the standard error of the regression coefficients associated with the covariate of the intermediate level and the remaining crossed factor are overestimated. When the ignored crossed factor is at the intermediate level, only the standard error of the regression coefficients associated with the covariate of the bottom level is overestimated. In Study Two, longitudinal multilevel data were generated mirroring studies in which students are measured repeatedly and change schools over time. It was found that when the school level is modeled hierarchically above the student level rather than as a crossed factor, part of the variance at the school level is added to the student level, causing underestimation of the school-level variance and overestimation of the studentlevel variance and covariance. The standard errors of the intercept and the regression coefficients associated with the school-level predictors are underestimated, which may cause spurious significance for results. The findings of the dissertation enhanced our understanding of the functioning of CCREMs in both cross-sectional and longitudinal multilevel data. The findings can help researchers to determine when CCREMs should be used and to interpret their results with caution when they misspecify CCREMs.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Submitted by Neusa Fagundes (neusa.fagundes@unioeste.br) on 2018-02-08T19:10:01Z No. of bitstreams: 1 Karine_Dassoler2017.pdf: 1003941 bytes, checksum: f29baeb8bacac3432cb09c39d7db0b18 (MD5) / Made available in DSpace on 2018-02-08T19:10:01Z (GMT). No. of bitstreams: 1 Karine_Dassoler2017.pdf: 1003941 bytes, checksum: f29baeb8bacac3432cb09c39d7db0b18 (MD5) Previous issue date: 2017-07-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Paper is an extremely versatile material that, by possessing chemical, physical and mechanical unique properties, can have several applications such as writing and printing, newspaper production, sanitary papers, packaging, among others. Wood is the main raw material used in the paper industry and only 40 and 50% of its total initial mass is applied in paper production. The most explored wood fiber in this sector is eucalyptus and Brazil has the largest surface area planted with trees. This monoculture has caused several environmental impacts, such as extreme dependence on agrochemicals and high consumption of water, typical of the species, which are worsened since eucalyptus is not a native Brazilian tree. It is extremely important the development of technologies that search for sustainable solutions and reduce these environmental impacts. Several studies have been carried out using alternative raw materials for paper manufacture. The results have shown that is possible to replace wood without major changes in the process and equipment already used. Wheat has significant importance in the global agricultural economy, since it is the second most-produced cereal. The wheat husk or bran is the grain part that is not used for milling flour production. It is a byproduct of the milling industries rich in cellulose and hemicellulose. Thus, this study aimed at using wheat bran as raw material for paper production by soda process. Three tests were performed, the first using a H-Factor of 800 and an alkali concentration of 14%, the second and the third using 15 minutes of time with alkali concentrations of 12% and 16%, respectively. The best operating condition was with an alkali concentration of 12% and cooking time of 15 minutes. In this condition, pulp yield was 35.08% and it was possible to produce paper in a proportion of up to 50% ratio of wheat bran pulp combined with eucalyptus pulp. It was possible to maintain the physical-mechanical properties in the paper produced, which is an alternative that causes less environmental impact during the production process and avail an agroindustrial residue. / O papel é um material extremamente versátil que, por possuir propriedades químicas e físico-mecânicas únicas, pode ter diversas aplicações: escrita e impressão, produção de jornais, papéis sanitários, embalagens, entre outras. A madeira é a principal matéria-prima utilizada na indústria papeleira e apenas 40 a 50% de sua massa total inicial é aproveitada na produção de papel. A fibra madeireira mais amplamente explorada no setor é o eucalipto, sendo que o Brasil abriga a maior área superficial plantada com essa árvore. Diversos são os impactos ambientais que essa monocultura causa, como a extrema dependência de agroquímicos e o elevado consumo de água, característico da espécie, os quais são agravados pelo fato de o eucalipto não ser uma árvore nativa brasileira. É de vital importância o desenvolvimento de tecnologias que busquem soluções sustentáveis e diminuam esses impactos. Diversos trabalhos vêm sendo realizados com o uso de matérias-primas alternativas para a fabricação de papel e os resultados mostram que é possível substituir a madeira sem grandes alterações no processo e equipamentos já utilizados. O trigo tem significativo peso na economia agrícola global, pois é o segundo cereal mais produzido no mundo. A parte do grão que não é destinada à moagem para produção de farinha é conhecida como casca ou farelo de trigo: um subproduto das indústrias moageiras, rico em celulose e hemicelulose. O objetivo deste trabalho foi utilizar o farelo de trigo como matéria-prima para produção de papel por meio do processo soda. Três ensaios foram realizados, o primeiro em função do Fator H de 800 e uma concentração de álcali de 14%, o segundo e o terceiro em função do tempo de 15 minutos com concentrações de álcali de 12% e 16%, respectivamente. A melhor condição operacional foi com uma concentração de álcali de 12% e tempo de cozimento de 15 minutos. Nesta condição, o rendimento da polpa foi de 35,08% e foi possível a produção de papel numa proporção de até 50% de polpa de farelo de trigo combinada com polpa de eucalipto. Foi possível a manutenção das propriedades físico-mecânicas no papel produzido, sendo este uma alternativa que causa menor impacto ambiental durante o processo produtivo e aproveita um resíduo agroindustrial.

This study was carried out with Beypazari trona ore having a grade about 85 % trona (Na2CO3.NaHCO3.2H2O). The main target of the study is the determination of calcinations and leaching parameters, which are the two main unit operations in the production of soda ash (Na2CO3) from trona ore. Calcination parameters / calcination duration, calcination temperature and particle size were determined by using three different heat treatment systems, namely laboratory type muffle furnace, up draught furnace and microwave oven. As an alternative, wet type microwave-induced calcination which completes the decomposition of trona in solution was also investigated. Thirty minutes of calcination time was sufficient for complete calcination of &amp / #8211 / 6.35 mm trona sample at 175 &deg / C with the muffle furnace. Calcination of trona with microwave treatment was completed in a shorter time. The nature of thermal reactions and structural changes of trona during calcination were elucidated by TG (Thermogravimetry), DTG (Derivative Thermogravimetry), SEM (Scanning Electron Microscope) and XRD (X-ray diffraction) analysis. The effect of heat treatment on grindability, specific surface area and decrepitation of trona were also investigated. In the last stage of the study, leaching parameters / leaching time, leaching temperature and pulp density were determined for both uncalcined and calcined samples. 80 % leach recovery was obtained in 4 minutes for &amp / #8211 / 6.35 mm particle size of uncalcined sample in 25 % pulp density while 100 % leach recovery was reached for the calcined samples under the same conditions.

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-09-27T18:51:38Z No. of bitstreams: 1 KALINE MELO DE SOUTO VIANA – TESE (PPGEP) 2006.pdf: 3746935 bytes, checksum: 4a030ab6637f715855808519f3e7825e (MD5) / Made available in DSpace on 2018-09-27T18:51:38Z (GMT). No. of bitstreams: 1 KALINE MELO DE SOUTO VIANA – TESE (PPGEP) 2006.pdf: 3746935 bytes, checksum: 4a030ab6637f715855808519f3e7825e (MD5) Previous issue date: 2009-02-06 / Para a avaliação de diafragmas alternativos ao de amianto para produção de cloro e soda cáustica a partir da eletrólise da salmoura, foi utilizada uma célula eletroquímica em escala de bancada pelo processo diafragma. O objetivo foi investigar a possível substituição dos diafragmas de amianto por diafragmas de PEUAPM. Desta forma, este trabalho foi dividido em duas etapas. Na primeira etapa, foi realizada a investigação da resistência química do PEUAPM na forma de fibras, em meio ácido, básico e salino, numa temperatura de 90ºC, simulando-se as condições de operação das células eletroquímicas para produção cloro-soda. Para isto, foram utilizados os ensaios de infravermelho (FTIR), calorimetria diferencial exploratória (DSC), tração e microscopia eletrônica de varredura (MEV). Na segunda etapa, foram realizadas eletrólises e para isto foram confeccionados diafragmas com diferentes composições, variando de 100% amianto (diafragma utilizado como referência), passando pelo balanço de 5:95 a 90:10% de PEUAPM:amianto, até 100% PEUAPM. Para caracterização eletroquímica utilizou-se a determinação do número de MacMullim, bem como determinação dos parâmetros operacionais após 72 horas de eletrólise, numa temperatura de aproximadamente 85ºC, onde foram quantificados os seguintes parâmetros: eficiência de corrente, eficiência de energia, teor de cloretos e teor de cloratos, com o objetivo de correlacionar os dados obtidos com o novo diafragma aos dados obtidos com o diafragma de amianto (utilizado industrialmente). As condições operacionais utilizadas foram: diafragma de amianto, PEUAPM: amianto e PEUAPM, alimentação contínua de uma salmoura ácida (pH entre 3,5 e 4,0) na concentração de 320 g/L, densidade de corrente anódica de 2,63 KA/m2 com um tempo total de operação da célula eletrolítica na intensidade de corrente de 13,1 A de aproximadamente 72 horas, até atingir a concentração de 12% de NaOH (de acordo com os parâmetros industriais). Os resultados obtidos na etapa I, evidenciaram que as fibras de PEUAPM apresentam boa resistência ao ataque químico das soluções de NaCl, HCl e salmoura na temperatura de 90ºC, durante as 96 horas de exposição, apresentando apenas um início de oxidação, detectada pela presença de carbonilas, além de uma redução de 15% na cristalinidade das fibras de PEUAPM. Já por meio dos resultados obtidos na etapa II, observou-se que os diafragmas amianto/PEUAPM estudados não apresentaram bom empacotamento de fibras e que há uma tendência de redução da eficiência de corrente (E.C.) e eficiência de energia (E.E.) com o aumento do percentual de PEUAPM. Assim, conclui-se que as fibras de PEUAPM são um substituto em potencial para as fibras de amianto na produção cloro-soda. / To evaluate the alternatives diaphragm in relation to the asbestos in the chloro-alkali production from the electrolysis of brine, it was used an electrochemical cell in a laboratory scale by diaphragm process. The aim of this work is to study the substitution of asbestos diaphragm by UHMWPE. So, this work was divided in two steps. Firstly, it was done an investigation related to the chemical resistance of the UHMWPE in a fiber shape and in acid, base and salty solutions and 90oC of temperature. This condition was similar to the electrochemical cell operation in the chloro-alkali industry. It was used test of infrared (FTIR), differential scanning calorimetry (DSC), tensile strength and scanning electron microscopy (SEM) to evaluate the UHMWPE fibers. In the second step it was done the electrolysis with different compositions of diaphragm, changing from 100% of asbestos (used as reference) to 5:95, 90:10% of UHMWPE, until 100% of UHMWPE. To chemical characterization it was estimated the MacMullin number, as well the operational cell parameters, such as, current and energy efficiency, amounts of chlorates and chlorides. The aim of to study these parameters is the correlate the new diaphragm with the asbestos (used currently in the industry). The operational conditions used in this study were: continue feed of acid brine (pH from 3.5 to 4.0), concentration of 320 g/L, anodic current density of 2.63 KA/m2, and total time operation in the electrolytic cell of approximately 74 ho urs (current intensity of 13.1A) until reach 12% of NaOH concentration (similar to the industrial conditions). The results obtained in the first step showed that the UHMWPE fibers presented good resistance to the chemical attack of NaCl, HCl and brine solution at 90oC and in the period of 96 hours of exposition. It was observed only an start of oxidation, with presence of carbonyl groups, also it was observed an decrease in 15% in the crystallinity of the UHMWPE fibers. From the results of the second step it was observed that the asbestos/UHMWPE diaphragms studied presented good fiber packing and a tendency to decrease current and energy efficiencies with the increase of the UHMWPE content. So, it was concluded that with the conditions of preparation of asbestos/UHMWPE diaphragm done in this study the use of these in the choro-alkali production still limited due to the low surface energy and physical interaction presented by the UHMWPE fibers and it was necessary an previous surface treatment of the fibers.

Orientador: Gustavo Ventorim / Resumo: O conceito de biorrefinaria surgiu do intuito de diminuir a dependência dos produtos oriundos do petróleo e seus consequentes problemas ambientais. Pesquisas buscam técnicas e materiais que substituam a matéria prima de origem fóssil por biomassa, agregando valor a produtos de origem renovável ou que anteriormente seriam descartados. A produção de combustíveis de 2ª geração (como bioetanol) possibilita o repasse de um custo razoável ao setor de transporte devido ao uso de matéria prima de baixo custo. A composição de forte associação entre celulose, hemicelulose e lignina exige uso de um método de pré-tratamento que atenue a interação entre os componentes da biomassa e facilite a conversão em bioprodutos. Este trabalho tem como objetivo estudar a combinação de pré-tratamentos, auto-hidrólise e polpação soda na obtenção de pasta celulósica a partir de cavacos de eucalipto. Esta polpa passa por processo de hidrólise ácida liberando açúcares que, na presença de microrganismos específicos (Saccharomyces cerevisiae) são fermentados a etanol. Cavacos de eucalipto pré-tratados por auto-hidrólise passaram por cozimentos soda em concentração de álcali ativo de 20%, 23% e 26%, estudando-se a influência da concentração de álcali no rendimento de produção de bioetanol. A polpação utilizando 20% de álcali ativo produziu rendimento de 130,30 L de etanol a partir de uma tonelada de cavacos, tendo maior impacto no rendimento que as polpações de 23% de álcali ativo, que foi responsável por um... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The concept of biorefinery appear from the idea of reducing dependence on petroleum products and their consequent environmental problems. Researches seek techniques and materials that substitute the feedstock of fossil origin for biomass, adding value to products of renewable origin or that would previously be discarded. The production of second-generation fuels (such as bioethanol) makes it possible to pass along a reasonable cost to the transportation sector due to low cost raw materials use. The strong association between cellulose, hemicellulose and lignin requires a pretreatment method that attenuates the interaction between biomass components and facilitates the conversion into bioproducts. It was studied the combination of, auto-hydrolysis and soda pulping (alkaline) pre-treatments to efficiently obtain cellulose must go through acid hydrolysis process. This pulp after being hydrolized liberates sugars that, in the presence of specific microorganisms (Saccharomyces cerevisiae), could be fermented to ethanol. Eucalyptus pretreated by auto-hydrolysis method were treated by soda pulping in active alkali concentration of 20%, 23%b and 26%, studying the influence of the alkali concentration on the yield of bioethanol. Pulping using 20% active alkali yielded 130,30L of ethanol from one ton of chips, which has better impact than the 23% active alkali pulping, which was responsible for a production of 118,8 L of ethanol and 26% active alkali pulping that produced 101,9L. All y... (Complete abstract click electronic access below) / Mestre

No description available.

Long-term changes of El Niño/Southern Oscillation (ENSO) are studied with the ensemble run of Simple Ocean Data Assimilation (SODA 2.2.6) and the Coupled Model Intercomparison Project Phase 5 (CMIP5). An eight member ocean reanalyses (SODA 2.2.6) from 1871 to 2008 is produced by using forcing from eight ensemble members of an atmospheric reanalysis. The ensemble reanalysis shows that El Niño has prominent decadal variability. Weak El Niños occur throughout the entire record whereas the occurrence of strong El Niños varies, with strong El Niño at the beginning and end of the record. The strength of La Niña is weaker than for El Niño, and has less variability. Although for any given El Niño year all ensemble members show the occurrence of El Niño, in some ensemble members the El Niño is strong while in others it is weak. When the timing of the onset of Westerly Wind Bursts (WWBs) occurs earlier in the year and the strength of WWBs is stronger, strong El Niño occurs. To study the importance of the background state in the tropical Pacific Ocean on ENSO, long-term trends of tropical Pacific SST, wind stress, subsurface temperature and the sub-tropical cells (STCs) are analyzed. The reanalysis shows that there is a slight cooling trend of SST in the central tropical Pacific due to an enhanced tropical Pacific circulation. Subsurface temperature also has a cooling trend. The STCs, which consist of equatorial upwelling, Ekman transport, extra-tropical subduction and pycnocline transport from the sub-tropical to the tropical region, strengthen from 1900 to 2008. When the STCs are accelerated, equatorial upwelling increases bringing cold water from the subsurface that cools the surface. ENSO variability is also analyzed in the CMIP5 historical experiments. Results show that most of the models have a realistic representation of the strength of ENSO; however, the location of warming generally extends too far to the west. Overall, properties of ENSO do not show a significant change in most of the CMIP5 models. One distinguishing difference between the CMIP5 models and SODA 2.2.6 is that ENSO in SODA 2.2.6 has prominent asymmetry between El Niño and La Niña, whereas ENSO in the CMIP5 models tends to have fairly symmetric El Niño and La Niña. In contrast with the reanalysis most of the CMIP5 models have warming trends at the surface and the transport of the STCs has a decreasing trend.

Male infertility is a significant public health problem. Although male factors are estimated to contribute to 50% of infertility, epidemiologic research on predictors of male infertility is scarce, and few modifiable risk factors have been identified. In particular, not much is known about the risk factors that determine semen quality in healthy males attempting to conceive. This dissertation uses data from Pregnancy Study Online (PRESTO), a preconception cohort of pregnancy planners residing in North America, to examine the role of several anthropometric and lifestyle exposures on semen quality. A subset of male participants provided data on semen volume, sperm concentration, and sperm motility using a novel in-home semen testing device. In the first study, we examined the effects of three anthropometric factors, body mass index (BMI), waist circumference, and weight gained since age 17 years, on semen quality. We found that men in the highest categories of BMI and waist circumference had poorer semen quality, particularly sperm concentration, motility, and total motile sperm count. Results were slightly stronger for waist circumference. Adult weight gain, however, was not appreciably associated with semen quality. Few studies have investigated the effect of marijuana use on semen quality. In the second paper we used PRESTO data to investigate the relationship between current marijuana use and semen parameters. We found that current male marijuana use was not appreciably associated with semen quality. Further control for potential confounders, including BMI, had little influence on the study results. In addition, results were similar among non-smokers of tobacco. The third paper focused on sugar-sweetened beverages (SSB) consumption and semen quality. We found that men who consumed higher quantities of SSB had poorer semen quality, particularly lower sperm concentration, total sperm count, and total motile sperm count. Adjustment for caffeine intake or current BMI had little effect on the results; however, the association between total SSB consumption was stronger among overweight and obese men. In conclusion, we observed that higher BMI and waist circumference were associated with decreased semen quality. In addition, increased sugar-sweetened beverage consumption may increase the risk of being classified as having low semen quality. Given that these exposures are common and modifiable, they may be important targets for public health interventions. / 2024-08-31T00:00:00Z

Orientador: Gustavo Ventorim / Resumo: O setor de combustíveis líquidos tem passado por uma constante mudança no cenário econômico mundial. Com a previsão de esgotamento das fontes de combustíveis fósseis, a corrida por novas alternativas se tornou um marco das gerações passadas e futuras. O denominado etanol celulósico produzido através da biomassa pode ser a chave para a questão energética mundial, no entanto, este tipo de produto encontra como barreira o desenvolvimento de tecnologias mais acessíveis e a custos menores. Dentre os materiais utilizados, a madeira pode apresentar vantagens como: baixa perda por degradação, quando estabelecida rotações silviculturais não está sujeita a sazonalidade, dentre outras. Neste contexto, o presente trabalho teve como objetivo encontrar uma nova rota de produção de etanol celulósico a partir de cavacos de Eucalyptus urograndis e estudar o efeito da dosagem de fermento na etapa de conversão da glicose a etanol. O estudo foi realizado utilizando os processos de auto- hidrólise e polpação soda (23% de álcali ativo), como etapa de pré-tratamento da matéria prima, seguidos então, pela hidrólise ácida com ácido sulfúrico 72% e fermentação com 10, 20 e 30g da levedura Saccharomyces cerevisiae. Ao final foram analisados os rendimentos alcançados. O processo de fermentação mostrou uma eficácia de 90,05%, 88,29% e 79,57% para 10, 20 e 30 g, respectivamente, rendimentos ótimos para esta etapa. A utilização de 10 g foi suficiente para a etapa de fermentação frente as outras quantidades... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The liquid fuel industry has been undergoing a constant change in the world economic scenario for years, with the forecast of depletion of fossil fuel sources, the race for new alternatives has become a mark of past and future generations. The so-called cellulosic ethanol produced through biomass may be the key to the world energy issue, however, this type of product finds as a barrier the development of technologies more accessible and at lower cost. Among the materials used, wood can present advantages in terms of low degradation loss, when established silvicultural rotations are not subject to seasonality, among others. In this context, the present work aimed to find a new route for the production of cellulosic ethanol from Eucalyptus urograndis chips and to study the effect of yeast dosage on the conversion of glucose to ethanol. he process was carried out using the processes of autohydrolysis and sodium pulping (23% alcohol on the market), as the main process of pre-processing the raw material, followed by acid hydrolysis with 72% sulfuric acid and fermentation with 10, 20 and 30g of yeast Saccharomyces cerevisiae, at the end of the harvest. The fermentation process has an advantage of 90.05%, 88.29% and 79.57% for 10, 20 and 30 g, respectively, described as excellent for this stage. The use of 10g was sufficient for a fermentation step compared to other sources (20 and 30g), thus, a ratio of 1g of yeast to 4.7g.L-1. As a global result of the 100g initial chip discarding... (Complete abstract click electronic access below) / Mestre