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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.
101

âFluorose dentÃria em crianÃas de seis a oito anos residentes na Ãrea de abrangÃncia de uma unidade bÃsica de saÃde, Fortaleza-Ce: estudo de caso-controleâ / Dental fluorosis in 6-8-year-old children living in the abrangency area of a primary health center in Fortaleza-CE: case-control study

Ana Karine Macedo Teixeira 29 June 2009 (has links)
O aumento da prevalÃncia de fluorose dentÃria à observado tanto em comunidades com Ãgua fluoretada como em Ãreas nÃo fluoretadas, sugerindo assim a ingestÃo de flÃor por outras fontes alÃm da Ãgua de abastecimento pÃblico. O objetivo deste trabalho foi pesquisar a fluorose dentÃria em crianÃas de seis à oito anos no MunicÃpio de Fortaleza-CE e investigar possÃveis fatores de risco ou de proteÃÃo para a fluorose, alÃm de sua relaÃÃo com fatores socioeconÃmicos. Tratou-se de um estudo do tipo caso-controle, desenvolvido no Centro de SaÃde da FamÃlia (CSF) Terezinha Parente. A amostra constou-se de 57 crianÃas sem fluorose (grupo-controle) e 67 crianÃas com fluorose (grupo de casos), onde foi utilizado o Ãndice de Dean para a mediÃÃo da fluorose e definiÃÃo de casos e controles. Os dados foram obtidos atravÃs de entrevistas, com base em um roteiro estruturado com os pais das crianÃas. A anÃlise dos dados foi realizada no programa Epi-Info Windows, onde se utilizou o teste exato de Fisher para verificar a associaÃÃo entre as variÃveis, considerando significativo quando o valor de p<0,05. Calculou-se ainda o odds ratio com intervalo de confianÃa de 95%. Foi observada uma associaÃÃo estatisticamente significante entre a variÃvel condiÃÃo de moradia e fluorose dentÃria (p=0,024 e OR=3,82), enquanto para os outros fatores socioeconÃmicos nÃo foi observada nenhuma associaÃÃo. Com relaÃÃo à fonte de Ãgua para consumo, os dentifrÃcios fluoretados e suplementos de flÃor, nÃo se verificou nenhuma associaÃÃo significante com a presenÃa de fluorose. Observou-se, porÃm, que as crianÃas que iniciaram o consumo de leite em pà reconstituÃdo com Ãgua antes dos dois anos de idade apresentaram uma chance de 4,53 vezes maior de apresentar fluorose (p=0,036). E as crianÃas que nÃo mamaram apresentaram uma chance de 6,66 vezes maior de possuir fluorose dentÃria do que as que mamaram por mais de seis meses (p=0,007). A amamentaÃÃo se configurou como um fator de proteÃÃo para a fluorose dentÃria, enquanto a ingestÃo de leite em pà reconstituÃdo com Ãgua antes dos dois anos se apresentou como um fator de risco. à de fundamental importÃncia o estÃmulo à amamentaÃÃo por parte dos profissionais de saÃde, para garantir nÃo sà uma melhor saÃde geral das crianÃas, mas tambÃm uma melhor saÃde bucal. / The increase of dental fluorosis has been observed in fluoridated and non-fluoridated locations, suggesting the fluoride intake by others sources besides water fluoridated. The aim of this study was to investigate the dental fluorosis in children aged 6 to 8 in Fortaleza, CearÃ, to identify risk and protection factors for dental fluorosis and to verify the possible associated of fluorosis with socioeconomic status. It was a case-control study realized at the health center Terezinha Parente. A total of 57 controls and 67 cases were examined by the Dean index. Data was obtained by interviewing the parents of the children, based on a structured questionnaire. Analyses of the data occurred at the Epi-Info Windows program by the Fisher test with p<0,05 and the odds ratio was calculated, with confidence interval of 95%. Statistically associated between dental fluorosis and the variable condition of live was observed (p=0,024 e OR=3,82), while no association was observed by the others socioeconomic factors. Fluoride intake by children from water, dentifrice and fluoride supplement demonstrated no significant results. But, the children who consumed powdered milk reconstituted with water before 2 years old presented 4,53 more chance to have dental fluorosis (p=0,036). And the children who have not breastfeeding presented 6,66 more chance to have fluorosis than that who breastfeeding for more than 6 mouths (p=0,007). Breastfeeding showed to be a protections factor to dental fluorosis and the consume of powdered milk reconstituted with water before 2 years old demonstrated to be risk factor in this population. Itâs important to health workers recommend breastfeeding to guarantee the oral health of children.
102

A Contact Element Approach with Hysteresis Damping for the Analysis and Design of Pounding in Bridges

Muthukumar, Susendar 26 November 2003 (has links)
Earthquake ground motion can induce out-of-phase vibrations between adjacent structures due to differences in dynamic characteristics, which can result in impact or pounding of the structures if the at-rest separation is insufficient to accommodate the relative displacements. In bridges, seismic pounding between adjacent decks or between deck and abutment can result in localized deck damage, bearing failure, damage to shear keys and abutments, and even contribute to the collapse of bridge spans. This study investigates pounding in bridges from an analytical perspective. A simplified nonlinear model of a multiple-frame bridge is developed in MATLAB incorporating the effects of inelastic frame action, nonlinear hinge behavior and abutments. The equations of motion of the bridge response to longitudinal ground excitation are assembled and solved using the fourth-order Runge-Kutta method. Pounding is simulated using contact force-based models such as the linear spring, Kelvin and Hertz models, as well as the momentum-based stereomechanical method. In addition, a Hertz contact model with nonlinear damping (Hertzdamp model) is also introduced to model impact. The primary factors controlling the pounding response are identified as the frame period ratio, ground motion effective period ratio, restrainer stiffness ratio and frame ductility ratio. Pounding is most critical for highly out-of-phase frames. Impact models without energy dissipation overestimate the stiff system displacements by 15%-25% for highly out-of-phase, elastic systems experiencing moderate to strong ground excitation. The Hertzdamp model is found to be the most effective in representing impact. Traditional column hysteresis models such as the elasto-plastic and bilinear models underestimate the stiff system amplification and overestimate the flexible system amplification due to impact, when compared with stiffness and strength degrading models. Strength degradation and pounding are critical on the stiff system response to near field ground motions, for highly out-of-phase systems. Current design procedures are adequate in capturing the nonlinear hinge response when the bridge columns are elastic, but require revisions such as the introduction of time dependent reduction factors, and a frame design period to work for inelastic situations. Finally, a bilinear truss element with a gap is proposed for implementing energy dissipating impact models in commercial structural software.
103

Experimental Analysis Of Curved Laminated Beam

Uzhan, Tevfik 01 May 2010 (has links) (PDF)
ABSTRACT EXPERIMENTAL ANALYSIS OF CURVED LAMINATED GLASS BEAM Uzhan, Tevfik M.S., Department of Engineering Sciences Supervisor: Prof. Dr. M. Z&uuml / lf&uuml / ASik May 2010, 33 Pages In this thesis, experimental studies are carried out on curved laminated glass beams to form a database for the scientists who may like to test their mathematical models. Beams which are only free to rotate and constrained in radial direction at both ends are tested to make the data available for further calculations. Test setup is prepared to minimize error that could occur due to test setup and data readings. Material testing machine and 4 channel data collecting machine are used to measure the signals at the strain gauges located over the glass beam. Within the range of force applied to the specimens, laminated curved beam shows linear behavior without any fracture. Data collected from the specimens are in conformance with each other. Results obtained from experiments are compared with the results obtained from the mathematical model developed by ASik and Dural (2006). As it is observed from the graphs presented, experimental results from the tests and numerical results from the mathematical model are in good agreement.
104

Kvadratūrinių formulių liekamųjų narių įverčiai ir jų analizė / Error estimates of quadrature formulas and their analysis

Leščiauskienė, Vaiva 06 June 2006 (has links)
In this paper the problems of finding error estimates of quadrature formulas are discussed. A method proposed by K.Plukas was tested. One of the most important tests was the one determining the error estimates that are too optimistic. The results have shown that there are 1/8 of such error estimates and that there is no visible pattern when they occur. The second very important test was the one that shows how many iterations are needed to get the estimate of integral. After comparing the results to the ones produced by method of T.O.Espelid it was obvious that method of K.Plukas produced results even when method of T.O.Espelid was not able to. Comparison of these results have also shown that method of K.Plukas is not always as effective as method of T.O.Coteda, i.e. in many cases method of K.Plukas produced the result after more iterations than method of T.O.Coteda.
105

Antimicrobial effect of yogurt lactic acid bacteria and muscadine products on Enterobacter sakazakii

Weng, Wei-Lien, January 2008 (has links)
Thesis (Ph.D.)--Mississippi State University. Department of Food Science, Nutrition and Health Promotion. / Title from title screen. Includes bibliographical references.
106

Detection of Enterobacter sakazakii in South African food products

Kemp, Francisca 12 1900 (has links)
Thesis (Msc Food Sc (Food Science))--University of Stellenbosch, 2005. / It is estimated by the World Health Organisation (WHO) that thousands of millions of cases of foodborne diseases occur world–wide every year. Enterobacter sakazakii is a member of the family Enterobacteriaceae and has been identified as an occasional contaminant of powdered infant formula milk (IFM). Enterobacter sakazakii is an opportunistic emerging pathogen and has the ability to cause a severe form of neonatal meningitis. This organism was referred to as “yellow pigmented Enterobacter cloacae” until 1980 after which it was renamed as E. sakazakii. The current method for the detection of E. sakazakii is very time consuming and includes pre–enrichment, enrichment in Enterobacteriaceae enrichment broth, subsequent plating on violet red bile glucose agar and subculturing on tryptone soy agar. In this study a polymerase chain reaction (PCR) method was developed for the identification of the presence of E. sakazakii in infant food products. A part of the 16S ribosomal RNA (rRNA) gene from E. sakazakii was amplified using the primer pair Esak2 and Esak3. An internal amplification control (IAC) was constructed as part of the PCR detection method. The 850 base pair (bp) E. sakazakii PCR product was digested with AluI and the two fragments containing the primer binding sites were ligated, resulting in a 240 bp IAC. During this study a positive band for both the target DNA (850 bp) and the IAC (240 bp) was simultaneously observed when the IAC was added to the PCR mixture at a concentration of 0.72 pg.ml-1. Four of 22 South African food products tested positive for the presence of E. sakazakii, using both the PCR and recommended culturing methods. The PCR method was used successfully for the detection of E. sakazakii within three days and thus provides a possible alternative and improvement on the recommended current culturing methods. Other microorganisms present in the products tested included Escherichia coli, Klebsiella pneumoniae, Raoultella terrigena (“Klebsiella terrigena”) and Chryseomonas luteola. Since E. sakazakii is usually present in low numbers in food products, it is possible that these few cells are unevenly distributed in the products, making it important to take multiple samples when evaluating IFM and thereby ensuring that even low numbers of this pathogen are detected.
107

O método de circulantes, as fórmulas de Cardano e o teorema de Fermat para n=3

Melo, Rômulo de Oliveira Lins Vieira de 31 August 2017 (has links)
Submitted by Leonardo Cavalcante (leo.ocavalcante@gmail.com) on 2018-05-02T18:31:29Z No. of bitstreams: 1 Arquivototal.pdf: 790723 bytes, checksum: 7e439258b05733c014dcd3e7de230c1f (MD5) / Made available in DSpace on 2018-05-02T18:31:29Z (GMT). No. of bitstreams: 1 Arquivototal.pdf: 790723 bytes, checksum: 7e439258b05733c014dcd3e7de230c1f (MD5) Previous issue date: 2017-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this present work, principles and theorems associated to integers are returned, as well as eigenvalues and eigenvectors problems, highlighting a Hermitian matrix. Then it is emphasized to the Circulating Matrices, through which it is found the association to two well-defined polynomials: the representative and the characteristic. Later a brief account about the history of polynomial equations is made, drafting the Cardano-Tartaglia Formulas associated to them. Afterwards a unification is made in the resolution process of the polynomial equations of smaller degrees than the equal to 4, by means of the circulating matrices. The work is completed by proving a Fermat theorem for n = 3, using the Cardano-Tartaglia Formulas. / No presente trabalho, princípios e teoremas associados aos números inteiros são retomados, bem como problemas de autovalores e autovetores, sendo ressaltada a matriz Hermitiana. Em seguida é dado ênfase às Matrizes Circulantes, através das quais verifica-se a associação a dois polinômios bem definidos: o representante e o característico. Posteriormente realiza-se um breve relato acerca da história das equações polinomiais, destacandose as Fórmulas de Cardano-Tartaglia associadas às mesmas. Logo após é feita uma unificação no processo de resolução das equações polinomiais de graus menores do que o igual a 4, por meio das matrizes circulantes. O trabalho é finalizado, sendo provado o Teorema de Fermat para n = 3, recorrendo-se às Fórmulas de Cardano-Tartaglia.
108

Formulação não linear de ração para frangos de corte : modelagem e otimização /

Almeida, Marcel Alessandro de. January 2013 (has links)
Orientador:Marcos Franke Pinto / Co-orientador:Manoel Garcia Neto / Banca:Silvia Helena Venturoli Perri / Banca:Antonio Celso Pezzato / Resumo:As atuais estratégias de formulação de ração exigem a aplicação de novas ferramentas computacionais, que utilizam a modelagem matemática, dando suporte na tomada de decisão para uma nutrição de precisão. Por este motivo, destaca-se a programação não linear, que não visa apenas formular uma dieta que atenda às necessidades do animal, mas sim o custo mínimo e também maximizar a margem de lucro. Assim, o presente trabalho teve como objetivo validar a utilização do modelo não linear (PNL), com maximização do retorno econômico, através de estimativas de desempenho das aves e dos custos da ração, segundo a variação de preço do kg do frango de corte (preço médio histórico de 2009 e 2010), as fases de criação e do sexo. Para tanto, foram utilizados 480 pintos de corte, 240 machos e 240 fêmeas da mesma linhagem (Cobb 500), no período de 1 a 56 dias de idade. O delineamento experimental foi inteiramente ao acaso, totalizando 6 tratamentos (aumentando ou diminuindo em 25% ou 50% o preço médio histórico do frango vivo), com 4 repetições e 10 aves por parcela experimental. As aves foram alimentadas ad libitum com água e rações experimentais, formuladas à base de milho, farelo de soja, óleo de soja, suplemento vitamínico e mineral, calcário e fosfato bicálcico. Foi avaliado o desempenho (ganho de peso e consumo de ração), consumo total energético e a margem de lucro. Concluiu-se que o princípio não linear mostra-se mais apropriado, uma vez que as exigências de todos os nutrientes são automaticamente ajustadas pelo modelo matemático / Abstract:The current formulation strategies required the application of new computational tools that use mathematical modelling, supporting decision- making for a precision nutrition. For this reason, non-linear programming, which not only aims to formulate a diet that meets the needs of the animal, according to the minimum cost, but also maximize the profit margin. Thus, the present work had as objective to validate the use of nonlinear principle model (NLP), with maximizing economic returns through performance estimates of birds and feed costs, according to the price change of kg of chicken (average price history for 2009 and 2010), the phases of creation and of sex. Thus, we used 480 broiler chicks, 240 males and 240 females of the same strain (Cobb 500), during the period 1 to 56 days old. The experimental design was completely randomized, with a total of 6 treatments (T1-NLP 50; T2-NLP 25; T3-NLP normal; T4-PNL-25; T5-NLP-50 and T6-PL), with 4 repetitions and 10 birds per plot. The birds were fed ad libitum with experimental rations and water, formulated based on corn, soybean meal, soybean oil, mineral and vitamin supplement, dicalcium phosphate, and limestone. Compliance has been assessed (weight gain, feed conversion and consumption), total energy consumption and profit. It was concluded that the principle of nonlinear formulation is more suitable to meet the concept of precision nutrition for broilers, since the requirements of all nutrients are automatically adjusted by the mathematical model, estimated energy content- related, as distinct nutritional recommendations for stages and ages of broiler, according the program PPFR / Mestre
109

Desenvolvimento de métodos analíticos para avaliação da presença de elementos essenciais e potencialmente tóxicos em fórmulas infantis

Gamela, Raimundo Rafael January 2017 (has links)
O consumo de fórmulas infantis no Brasil, utilizadas como substituto do leite materno, tem aumentado nos últimos anos de forma significativa. Tal fato é uma preocupação para os órgãos de saúde pois, o aleitamento materno exclusivo até no mínimo 6 meses, deixou de fazer parte de nutrição da maioria dos lactentes. Os produtos utilizados como substituto do leite materno contêm quantidades suficientes de vitaminas e nutrientes que ajudam no desenvolvimento normal do organismo dos lactentes. Entretanto, além de elementos essenciais, podem conter elementos potencialmente tóxicos presentes na matéria prima ou oriundos das etapas de processamento e armazenamento das mesmas. No presente trabalho foram desenvolvidos métodos analítico para determinar a presença de elementos potencialmente tóxicos (As, Cd, Pb e Tl) e essenciais (Cu e Mn) em fórmulas infantis, utilizando espectrometria de absorção atômica de alta resolução com fonte contínua e forno de grafite e análise direta de sólidos. As amostras utilizadas neste trabalho foram obtidas nos mercados da cidade de Porto Alegre, RS, Brasil, todas na forma sólida (pó) com diferentes composições e matéria prima (arroz, aveia, soja e leite). As curvas de calibração foram realizadas com soluções padrão aquosas e os métodos otimizados foram aplicados nas amostras em estudo. Em todas as amostras os elementos As, Cd, Pb e Tl apresentaram valores de concentração abaixo do limite de detecção. Das seis amostras analisadas, três apresentaram valores de concentração de Cu abaixo dos parâmetros mínimos estabelecidos pela legislação brasileira, enquanto que para o Mn todas amostras apresentaram valores de concentração dentro dos parâmetros mínimos da legislação brasileira. Os métodos desenvolvidos foram simples, exatos e precisos, podendo ser utilizados para análise de rotina. / The consumption of infant formula in Brazil, as a replacement of breast milk, has lately increased significantly. It is a major concern for health agencies because the exclusive breastfeeding up to at least 6 months is no longer part of most infants. The products used as a substitute of the breast milk contain sufficient amounts of vitamins and nutrients, which helps in the normal development of the infants. However, besides the essential elements, it may contain potentially toxic elements present in raw material or from of the processing and storage stages of the same. In the present work the presence of the essential (Cu e Mn) and potentially toxic elements (As, Cd, Pb e Tl) in infant formulas were evaluated. For this, analytical methods were developed for the determination of As, Cd, Cu, Mn, Pb and Tl using high-resolution continnum source graphite furnace atomic absorption spectrometry and direct solid sampling analysis in infant formulas. The samples were acquired in Porto Alegre’s market, RS, Brazil, all in powder form with different compositions and raw materials (rice, oats, soy and bovine milk). The calibration curves were performed with aqueous standard solutions and the optimized methods were applied in the study samples. In all samples, the concentration values of As, Pb, Cd and Tl were below of the limit of detection. For the analyzed samples, three of them present the concentration values of Cu lower than the minimum parameters established by Brazilian legislation, while for Mn, all samples present the concentration values within the minimum parameters of Brazilian legislation. The developed methods for the determination of these elements in infant formulas were simple, exacts and precise, and can be applicated for the routine analysis.
110

Formulação não linear de ração para frangos de corte: modelagem e otimização

Almeida, Marcel Alessandro de [UNESP] 09 June 2013 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-06-09Bitstream added on 2014-06-13T19:14:34Z : No. of bitstreams: 1 000744274.pdf: 4145154 bytes, checksum: 03899c25807489a3b4a1331eff2b8e8b (MD5) / The current formulation strategies required the application of new computational tools that use mathematical modelling, supporting decision- making for a precision nutrition. For this reason, non-linear programming, which not only aims to formulate a diet that meets the needs of the animal, according to the minimum cost, but also maximize the profit margin. Thus, the present work had as objective to validate the use of nonlinear principle model (NLP), with maximizing economic returns through performance estimates of birds and feed costs, according to the price change of kg of chicken (average price history for 2009 and 2010), the phases of creation and of sex. Thus, we used 480 broiler chicks, 240 males and 240 females of the same strain (Cobb 500), during the period 1 to 56 days old. The experimental design was completely randomized, with a total of 6 treatments (T1-NLP 50; T2-NLP 25; T3-NLP normal; T4-PNL-25; T5-NLP-50 and T6-PL), with 4 repetitions and 10 birds per plot. The birds were fed ad libitum with experimental rations and water, formulated based on corn, soybean meal, soybean oil, mineral and vitamin supplement, dicalcium phosphate, and limestone. Compliance has been assessed (weight gain, feed conversion and consumption), total energy consumption and profit. It was concluded that the principle of nonlinear formulation is more suitable to meet the concept of precision nutrition for broilers, since the requirements of all nutrients are automatically adjusted by the mathematical model, estimated energy content- related, as distinct nutritional recommendations for stages and ages of broiler, according the program PPFR

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