O objetivo do presente estudo foi determinar, em presença de multi-carboidrase (MC: galactomananase, xilanase, beta-glucanase, e alfa-galactosidase) e fitase (10.000 FTU/g) o balanço nutricional, uso aparente da energia (EMA), a digestibilidade ileal aparente e estandardizada dos aminoácidos em diferentes ingredientes usados na alimentação de frangos de corte. Sob o delineamento inteiramente casualizado 1960 frangos machos (Cobb 500) foram distribuídos do 1 aos 21 dias de idade para receberem cinco tratamentos, em sete repetições com sete aves cada. A adaptação das aves às gaiolas, sob níveis nutricionais dietéticos recomendados à fase, se deu do 1º ao 10º dia de idade. A seguir, receberam as dietas experimentais dos 11 aos 18 dias, quando se procedeu a coleta de excretas, período esse, definido como Ensaio 1. A partir do 19º dia as aves receberam nova dieta até os 21 dias de idade, quando se deu o abate para amostragens do conteúdo ileal, período definido como Ensaio 2. As dietas do período experimental foram: dieta de referência e quatro dietas a base de milho (Ensaio 1) e quatro dietas a base de amido de milho (Ensaio 2). As dietas experimentais tinham como única fonte de proteína 30% do ingrediente testado, sendo fornecidas sob arranjo fatorial 2 MC (0 ou 200 mg/kg) x 2 fitase (0 ou 50 mg/kg). Os ingredientes testados foram: farelo de trigo, farelo de arroz, sorgo, farelo de canola, farelo de girassol, milho, farelo de soja e soja integral extrusada. Os dados foram submetidos à análise de variância utilizando o PROC GLM do SAS 9.2. As enzimas melhoraram (P < 0,05) o balanço de nutrientes, a EMA, digestibilidade ileal aparente e estandardizada dos aminoácidos nos diferentes ingredientes testados. Separada ou combinada a multi-carboidrase e fitase tiveram eficiência diferenciada para cada ingrediente estudado e utilizado na formulação das rações de frangos de corte na fase inicial, correspondente ao período de 14 aos 21 dias de idade / The aim of this study was to determine the effects of multi-carbohydrase (MC, that consist in: galactomannanase, xylanase, beta-glucanase and alpha-galactosidase) and phytase (10000 FTU/g of activity) the nutrients balance, apparent energy use (AME), apparent and standardized ileal amino acids digestibility in some feedstuffs fed to young chickens. Under a completely randomized design 1960 male broilers (Cobb 500) were allotted from 1 to 21 days old to receive five treatments in seven replicates with seven birds each. Birds cages adaptation under dietary nutritional levels recommended to the stage occurred from the 1st to 10th day of age. Then, the birds received the experimental diet from 11 to 18 days when was realized the excreta collection, period defined as Assay 1. From the 19th day the birds received the new diet until 21 days old when birds were slaughter for ileal digesta collection, this period was defined like Assay 2. The experimental diets were: one reference diet and four corn-based diets (Assay 1) and four corn-starch-based diets (Assay 2). The experimental diets containing 30% of ingredient test as a sole protein source in 2 MC (0 or 200 mg/kg) x 2 phytase (0 or 50 mg/kg) factorial arrangement. The ingredients tested were: wheat bran, rice bran, sorghum, canola meal, sunflower meal, corn, soybean meal and extruded soybean meal. Data were subjected to variance analysis using the PROC GLM of SAS 9.2. Enzymes improved (P < 0.05) the nutrients balance, AME use, apparent and standardized ileal amino acids digestibility on different tested ingredients. Isolated or combined the multi-carbohydrase and phytase have different efficiency for each studied ingredient and used on feed formulation for broiler chickens in initial phase, that corresponding from 14 to 21 days old

This work presents first-principles calculations of long-range intermolecular dispersion energies between two atoms or molecules as expressed in terms of the C6 dipole-dipole dispersion coefficients. In a series of publications, it has been shown by us that the complex linear polarization propagator method provides accurate ab initio and first-principles density functional theory values of the C6 dispersion coefficients in comparison with those reported in the literature. The selected samples for the investigation of dispersion interactions in the electronic ground state are the noble gases, n-alkanes, polyacenes, azabenzenes, and C60. It has been shown that the proposed method can also be used to determine dispersion energies for species in their respective excited electronic states. The C6 dispersion coefficients for the first π → π* excited state of the azabenzene molecules have been obtained with the adopted method in the multiconfiguration self-consistent field approximation. The dispersion energy of the π → π* excited state is smaller r than that of the ground state. It is found that the characteristic frequencies ω1 defined in the London approximation of n-alkanes vary in a narrow range and that makes it possible to construct a simple structure-to-property relation based on the number of -bonds for the dispersion interaction in these saturated compounds. However, this simple approach is not applicable for the interactions of the π-conjugated systems since their characteristic frequencies ω1 vary strongly depending on the systems. / <p>Report code: LIU-TEK-LIC-2006:2</p>

In this paper we address the problem of negative estimates of willingness to pay. We find that there exist a number of goods and services, especially in the fields of marketing and environmental valuation, for which only zero or positive WTP is meaningful. For the valuation of these goods an econometric model for the analysis of repeated dichotomous choice data is proposed. Our model restricts the domain of the estimates of WTP to strictly positive values, while also allowing for the detection of zero WTP. The model is tested on a simulated and a real data set.

This work studies guided wave propagation in pipes coated with thick highly viscoelastic coating materials. The main motivation for this study is the problems associated with Long Range Ultrasonic Testing (LRUT) of coated pipelines. The results reported in the literature show that the proper determination of the optimum LRUT parameters depends strongly on the bulk acoustic properties of the coating materials. The bulk acoustic properties of coating materials reported in the literature show that they could vary significantly depending on the coating material age, temperature and bonding level. The methods for acoustic characterisation of coating materials reported by other researchers, have been studied and it was found that they do not take into account the temperature changes and bonding level variation. In this work, the bulk acoustic properties of two highly viscoelastic bitumen based coating materials are investigated. The conventional methods for acoustic characterisation are studied and a new method for independent measurement of bulk shear properties of bitumen is developed. The bulk acoustic properties of bitumen based coating materials are also studied by two new characterisation methods. The first method derives the bulk coating material properties from experimental data on guided wave reflection coefficients. The second method derives the coating material bulk properties from experimentally measured guided wave attenuation data. It is demonstrated that these new methods deliver much more accurate values for the bulk acoustic properties when compared to the data measured by conventional methods. The second method is used to study the temperature effect on the bulk acoustic properties and it is demonstrated that temperature has a significant effect. The validity of the acoustic properties for the two bitumen materials is investigated through comparison between numerical predictions and experimental data measured for guided wave reflection coefficients and attenuation of the torsional T(0,1) and longitudinal L(0,2) guided wave modes. Good agreement is achieved in the frequency range between 20 kHz and 100 kHz, which is typical for LRUT of pipes.

[pt] Determinou-se experimentalmente o coeficiente local de troca de calor, para o escoamento turbulento interno, em tubos de seção transversal elíptica. As condições de contorno impostas foram, temperatura constante na parede e entrada abrupta, com canto vivo, em uma placa plana. Foram obtidos resultados na região de entrada e na região desenvolvida, cobrindo a faixa de número de Reynolds de 7 000 a 60 000. Foram investigadas as razões de aspecto 0,12, 0,25 e 0,5 e os resultados, comparados com os encontrados na literatura para placa plana e tubo circular. Uma diferença máxima de 16 por cento, foi encontrada em relação aos resultados para tubo circular. Portanto, a utilização de tubos elípticos em trocadores de calor é, em geral, vantajosa do ponto de vista térmico. / [en] Experiments were performed to determine local heat transfer coefficients for the turbulent flow in a duct with elliptical cross section. The boundary conditions imposed were isothermal wall and abrupt-contraction at the entrance built into a large wall. Both entrance-region and fully-developed results were obtained, whereas the Reynolds number was varied in the overall range 7,000-60,000. The aspect ratios 0.12, 0.25 and 0.5 were investigated and the results compared with the ones for parallel planes and for circular tubes, found in the open literature. The measured heat transfer coefficients displayed a maximum deviation of 16 percent relative to the results for the circular tube. Therefore, using elliptical ducts in heat exchangers is in general advisable as far as heat transfer is concerned.

This study dealt with shrinkage in multiple correlation coefficients computed for sample data when these coefficients are compared to the multiple correlation coefficients for populations and the effect of the ratio of utilized predictors to original predictors on the shrinkage in R square. The study sought to provide the rationale for selection of the shrinkage formula when the correlations between the predictors and the criterion are known and determine which of the three shrinkage formulas (Browne, Darlington, or Wherry) will yield the R square from sample data that is closest to the R square for the population data.

In recent years there were many debates and different opinions whether R&D spillover effects exist or not. In 1995 Coe and Helpman published a study about this phenomenon, based on a panel dataset, that supports the position that such R&D spillover effects are existent. However, this survey was criticized and many different suggestions for improvement came from the scientific community. Some of them were selected and analysed and finally led to a new model. And even though this new model is well compatible with the data, it leads to different conclusions, namely that there does not exist an R&D spillover effect. These different results were the motivation to run a spatial analysis, which can be done by considering the countries as regions and using an adequate spatial link matrix. The used methods from the field of spatial econometrics are described briefly and quite general, and finally the results from the spatial models (the ones which correspond to the non-spatial ones) are compared with the results from the non-spatial analysis. The preferred model supports the position that R&D spillover effects exist.

A fundamental step in the further developments of comprehensive modelling of the diffusive processes in liquids requires the possibility of obtaining reliable and accurate experimental data of the diffusion and thermodiffusion coefficients of multicomponent liquid systems. In the present work, we perform an experimental investigation of the diffusive properties of binary and ternary liquid systems. Two experimental techniques, the ‘Open Ended Capillary’ technique and the ‘Transient Interferometric Technique’ have been developed. Those techniques have been used for the experimental characterization of several systems composed of 1,2, 3,4-Tetrahydrnaphtalene, Isobutylbenzene and Dodecane at ambient temperature. Those particular species were selected as a simplified multicomponent system modelling the fluids contained in natural crude oils reservoirs. <p>For each of these techniques, experimental set-ups were designed, implemented and calibrated. The procedures for identifying the ternary diffusion coefficients from the measured compositions fields were studied in details. <p>The Open Ended Capillary Technique was applied under gravity condition to study isothermal diffusion binary and ternary systems. Difficulties related to a new procedure for interpreting the data collected at short times of the experiments are highlighted and its implication in the generalization of the technique for the study of multicomponent systems is discussed.<p>The Transient Interferometric Technique was used to perform an experimental study of three binary systems under gravity conditions. It was also applied for the investigation of ternary systems under microgravity condition in the frame of the DSC on SODI experiment, which took place aboard the International Space Station in 2011. The experimental results are reported and the analysis of the accuracy of the technique is presented. The TIT is the first technique ever providing accurate experimental measurements of the complete set of diffusion and thermodiffusion coefficients for ternary liquid systems.<p> / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

Ce travail se propose d'étudier deux problèmes complémentaires concernant des systèmes différentiels à coefficients aléatoires étudiés au moyen de simulations de Monte Carlo. Le premier problème consiste à calculer la loi à un instant t* de la solution d'une équation différentielle à coefficients aléatoires. Comme on ne peut pas, en général, exprimer cette loi de probabilité au moyen d'une fonction connue, il est nécessaire d'avoir recours à une approche par simulation pour se faire une idée de cette loi. Mais cette approche ne peut pas toujours être utilisée à cause du phénomène d'explosion des solutions en temps fini. Ce problème peut être surmonté grâce à une compactification de l'ensemble des solutions. Une approximation de la loi au moyen d'un développement de chaos polynomial fournit un outil d'étude alternatif. La deuxième partie considère le problème d'estimer les coefficients d'un système différentiel quand une trajectoire du système est connue en un petit nombre d'instants. On utilise pour cela une méthode de Monté Carlo très simple, la méthode de rejet, qui ne fournit pas directement une estimation ponctuelle des coefficients mais plutôt un ensemble de valeurs compatibles avec les données. L'examen des propriétés de cette méthode permet de comprendre non seulement comment choisir les différents paramètres de la méthode mais aussi d'introduire quelques options plus efficaces. Celles-ci incluent une nouvelle méthode, que nous appelons la méthode de rejet séquentiel, ainsi que deux méthodes classiques, la méthode de Monte-Carlo par chaînes de Markov et la méthode de Monte-Carlo séquentielle dont nous examinons les performances sur différents exemples. / This work addresses two complementary problems when studying differential systems with random coefficients using a simulation approach. In the first part, we look at the problem of computing the law of the solution at time t* of a differential equation with random coefficients. It is shown that even in simplest cases, one will usually obtain a random variable where the pdf cannot be computed explicitly, and for which we need to rely on Monte Carlo simulation. As this simulation may not always be possible due to the explosion of the solution, several workarounds are presented. This includes displaying the histogram on a compact manifold using two charts and approximating the distribution using a polynomial chaos expansion. The second part considers the problem of estimating the coefficients in a system of differential equations when a trajectory of the system is known at a set of times. To do this, we use a simple Monte Carlo sampling method, known as the rejection sampling algorithm. Unlike deterministic methods, it does not provide a point estimate of the coefficients directly, but rather a collection of values that “fits” the known data well. An examination of the properties of the method allows us not only to better understand how to choose the different parameters when implementing the method, but also to introduce more efficient methods. This includes a new approach which we call sequential rejection sampling and methods based on the Markov Chain Monte Carlo and Sequential Monte Carlo algorithms. Several examples are presented to illustrate the performance of all these methods.

L'objectif de cette thèse est de proposer une solution d'indexation ``scalable'' et basée objet de flux vidéos HD compressés avec Motion JPEG2000. Dans ce contexte, d'une part, nous travaillons dans le domaine transformé hiérachique des ondelettes 9/7 de Daubechies et, d'autre part, la représentation ``scalable'' nécessite des méthodes en multirésolution, de basse résolution vers haute résolution. La première partie de ce manuscrit est dédiée à la définition d'une méthode d'extraction automatique des objets en mouvement. Elle repose sur la combinaison d'une estimation du mouvement global robuste et d'une segmentation morphologique couleur à basse résolution. Le résultat est ensuite affiné en suivant l'ordre des données dans le flux scalable. La deuxième partie est consacrée à la définition d'un descripteur sur les objets précédemment extraits, basé sur les histogrammes en multirésolution des coefficients d'ondelettes. Enfin, les performances de la méthode d'indexation proposée sont évaluées dans le contexte de requêtes scalables de recherche de vidéos par le contenu. / This thesis aims at proposing a solution of scalable object-based indexing of HD video flow compressed by MJPEG2000. In this context, on the one hand, we work in the hierarchical transform domain of the 9/7 Daubechies' wavelets and, on the other hand, the scalable representation implies to search for multiscale methods, from low to high resolution. The first part of this manuscript is dedicated to the definition of a method for automatic extraction of objects having their own motion. It is based on a combination of a robust global motion estimation with a morphological color segmentation at low resolution. The obtained result is then refined following the data order of the scalable flow. The second part is the definition of an object descriptor which is based on the multiscale histograms of the wavelet coefficients. Finally, the performances of the proposed method are evaluated in the context of scalable content-based queries.