A cromatografia é uma técnica de separação cuja classificação se dá por meio do estado físico da fase móvel (líquido, gasoso, supercrítico, entre outros). Dentre as técnicas cromatográficas mais utilizadas e cujo conhecimento é bastante conhecido está a cromatografia gasosa. Embora esta técnica tenha sido bastante estudada existem ainda algumas vertentes que não totalmente estudadas, sendo uma delas a cromatografia gasosa de alta pressão na entrada da coluna (HIPGC). A HIPGC destaca por oferecer vantagens analíticas como alta eficiência, maior velocidade no tempo de análise e também facilita a migração de compostos com alta massa molecular. As desvantagens e dificuldades estão concentradas na instrumentação. O uso de alta pressão requer conexões que suportem tal pressão, sistema de injeção adequado a fim de eliminar vazamentos entre outros. Neste trabalho, sucessivos sistemas instrumentais foram montados visando o desenvolvimento, aprimoramento e avaliação de um sistema instrumental simples e versátil para HIPGC. Na avaliação do sistema foi utilizada coluna capilar empacotada pelo método \"slurry packed\". A escolha da coluna foi realizada a partir de curvas de eficiência de Van deemter. O sistema instrumental desenvolvido para HIPGC é apropriado para pressões de entrada de até 1800 psi. Além disso, este sistema apresentou boa reprodutibilidade nas análises e não apresentou vazamentos. Os resultados mostraram o potencial da técnica HIPGC na redução do tempo de análise. / Chromatography is a separation technique whose classification takes place by means of the physical state of the mobile phase (liquid, gas, supercritical, etc.). Among the most commonly used chromatographic techniques and whose knowledge is well known is gas chromatography. Although this technique has been widely exploited there are some topics which weren\'t fully investigated, one of them being high-pressure chromatography column input (HIPGC). HIPGC shows analytical advantages as high efficiency, faster analysis time and facilitates the migration of compounds with high molecular mass. The main difficulties in HIPGC are found in the instrumentation. The high pressure requires an appropriate connection that works in this range of pressure and one injection system suitable to transport the sample at different pressures. In this work, different instrumental systems were assembled to develop equipment to HIPGC that is simple and versatile. In the system evaluation was used capillary columns packed by methodology\'s \"slurry packed\" were used. The choice of the column was made from van Deemter efficiency curves. The system developed for instrumental HIPGC it is appropriate for inlet pressures up to 1800 psi. Furthermore, this system showed good reproducibility of analysis and didn\'t show leaks. The results showed the potential of HIPGC, such as shorter analysis time.

Dentro do conjunto de aspectos relacionados à elaboração de projetos em estruturas de aço e mistas de aço e concreto, destaca-se como de grande importância e interesse, para fins de dimensionamento, a consideração de elementos estruturais submetidos a temperaturas elevadas. Nesse sentido, o presente trabalho tem como objetivo principal propor a construção de modelos numéricos tridimensionais de pilares de aço pertencentes a sistemas estruturais correntes da construção civil, para análise em situação de incêndio, com vistas a simular numericamente a evolução dos níveis de temperatura ao longo do tempo com posterior acoplamento termoestrutural. Considera-se uma análise paramétrica com vista a variar as restrições axiais totais e parciais da barra, no referente aos deslocamentos axiais, contemplando desde a situação de extremidade livre até a restrição completa em resposta à consideração de apoio do tipo fixo, por exemplo. Os resultados numéricos são comparados a ensaios experimentais de outros autores, bem como com outros trabalhos numéricos já publicados. São obtidas respostas de deslocamentos axiais e laterais do modelo termoestrutural para diversas disposições de paredes em relação ao perfil, bem como gráficos do acréscimo de força axial introduzido no sistema pela restrição axial. Os estudos aqui realizados poderão servir como base para novas pesquisas tanto no campo numérico quanto experimental, assim como para futuras revisões da ABNT NBR 14323:1999, buscando contemplar situações de interesse não abordadas neste documento normativo. Os resultados da pesquisa apontam que a consideração do campo térmico com a inclusão da alvenaria no modelo termoestrutural pode melhorar consideravelmente o desempenho do elemento estrutural em situação de incêndio. / Within the set of aspects related to the development of researches in steel and composite steel and concrete structures, stands out with great importance and interest, aiming to dimension, the consideration of structural elements subjected to high temperatures. In this way, the present work has as main objective to propose the construction of three-dimensional numerical models of steel columns that belong to current structural systems of civil construction, for examination in fire situation, aiming to simulate numerically the evolution of temperature levels throughout of time with later termoestrutural coupling. It will be considered a parametric analysis in order to vary the total and partial axial restraint in respect to the axial displacements, since the free end situation until the complete restriction in response to the consideration of support for the fixed type, for example. The numerical results are compared to experimental tests made by other authors, as well as with others numerical works already published. Answers are obtained from axial and lateral displacements of the thermo structural model to many displacement of wall related to the profile, also charts of adding axial force introduced into the system by the axial restraint. The results of the current research could serve as a basis for further research in both the numerical field or experimental, also for future revisions of ABNT NBR 14323:1999, aiming to see situations of interest not studied in the same normative document. The results of this work show that consideration of thermal field with the inclusion of masonry in the thermo structural model can, significantly, improve the performance of the structural element in a fire situation.

Dans ce document, nous étudions deux problèmes de sectorisation et proposons plusieurs méthodes de résolution exactes basées sur la décomposition de Dantzig-Wolfe et la génération de colonnes. Nous proposons deux modélisations en fonction de la manière d’appréhender l’objectif du problème qui consiste à obtenir des secteurs compacts. Pour chacune des modélisations, nous comparons des approches de résolution exactes basées sur des formulations compactes ou sur des formulations étendues obtenues par la décomposition de Dantzig-Wolfe. Le premier type de modèles proposé définit la fonction objectif à la manière d’un problème de p-median. Concernant les méthodes de résolution pour ce type de modèle, l’accent est mis sur l’accélération de la convergence de l’algorithme de génération de colonnes en mettant en place des techniques d’agrégation de contraintes afin de réduire la dégénérescence de l’algorithme du simplexe. Les expérimentations numériques montrent que la méthode d’agrégation de contraintes proposée permet effectivement de réduire le nombre d’itérations dégénérées. Cependant, elle ne suffit pas à accélérer l’algorithme de branch-and-price. Le choix d’utilisation de la formulation compacte ou de la formulation étendue dépend du type d’instances résolu. Le second type de modèles formule l’objectif d’une manière assez proche de celui des problèmes de p-centre. L’utilisation d’un tel objectif complexifie la résolution des sous-problèmes de génération de colonnes. L’accent est donc mis sur la conception d’algorithmes de branch-and-bound et de programmation dynamique pour les résoudre efficacement. Les expériences montrent que l’algorithme de branch-and-price surpasse les approches de résolution utilisant une formulation compacte du problème. / In this document, we study two districting problems and propose several exact methods, based on Dantzig-Wolfe decomposition and column generation, to solve them. For each model, we compare exact approaches based either on compact formulations or on extended formulations obtained using Dantzig-Wolfe decomposition. The first type of model that we propose defines the objective function in a p-median problem fashion. Regarding the methods used to solve that kind of model, we emphasize accelerating the convergence of the column generation algorithm by designing constraint aggregation techniques in order to reduce the degeneracy in the simplex algorithm. Numerical experiments show that this constraint aggregation method indeed reduces the proportion of degenerated iterations. However, it is not enough to speed up the branch-and-price algorithm. Choosing to tackle the problem through either a compact formulation or an extended formulation depends on the structure of the instances to solve. The second type of model formulates the objective function in a way quite similar to that of p-centre problems. Using such an objective function induces complex column generation subproblems. We focus on designing branch-and-bound and dynamic programming algorithms in order to solve them efficiently. Experiments show that the branch-and-price approach surpasses any proposed method based on compact formulations of the problem.

Este trabalho tem como objetivo investigar o comportamento pós-pico de pilares com concretos de alta resistência confinados com e sem adição de fibras metálicas, submetidos à flexo-compressão. Para tanto, realizou-se inicialmente uma extensa revisão bibliográfica sobre o tema, na qual, elencaram-se os principais fatores que influenciam o comportamento pós-pico desses elementos estruturais. Em seguida, desenvolveram-se estudos paramétricos com o intuito de estabelecer os modos de influência de cada fator. Com base nesses estudos preliminares, um programa experimental, dividido em duas fases, foi proposto. Na primeira fase, ensaiaram-se vinte e seis pilares de concreto armado e 14 pilares de concreto simples. Três fatores foram estudados: a taxa de adição de fibras metálicas, a taxa de armadura transversal e a resistência à compressão do concreto. Os pilares possuíam seções transversais quadradas com dimensões 15 cm x 15 cm e altura de 50 cm e foram ensaiados à compressão centrada com controle de deslocamento. Observou-se que os três fatores analisados influenciam diretamente a ductilidade desses elementos estruturais e que, por meio de adição de fibras metálicas, é possível garantir índices de ductilidade aceitáveis para os pilares com concreto de alta resistência. Outrossim, analisando-se os diagramas força vs. deformação dos pilares, observou-se que para o primeiro pico de força, toda a seção resiste a esforços de compressão e que a adição de fibras melhora o trabalho conjunto entre o cobrimento e o núcleo do pilar. Finalizando esta fase, propuseram-se modificações para o modelo para concreto confinado de Cusson e Paultre (1995), de modo que, permitisse ao mesmo modelar o comportamento do concreto confinado com e sem adição de fibras metálicas. Na segunda fase do programa experimental, quinze pilares de concreto armado foram ensaiados a compressão excêntrica. Essa fase teve como objetivo investigar a influência da excentricidade, da taxa de armadura transversal e da taxa de adição de fibras metálicas no comportamento pós-pico desses elementos estruturais. Os pilares, nessa fase, possuíam seção transversal quadrada com dimensões de 15 cm x 15 cm e altura de 170 cm. Para realização dos ensaios foi confeccionado um par de rótulas unidirecionais, as quais apresentaram excelente desempenho, conseguindo transferir integralmente o momento externo aplicado ao pilar. Observou-se que, tanto a flambagem das barras da armadura longitudinal, quanto a perda de massa de concreto nesses pilares ocorrem de modo bem mais crítico que nos pilares submetidos à compressão centrada. Constatou-se, ainda, que quando os valores dos três fatores analisados são elevados, a ductilidade desses elementos estruturais é melhorada. Finalmente, foi observado que o efeito da flexão faz com que as tensões de confinamento se distribuam de modo diferenciado dentro da seção transversal dos pilares; contudo, observou-se que a tensão de confinamento na região comprimida da seção transversal pouco é modificada. / This thesis aims to investigate the ductility of high strength concrete columns, with confinement and/or with steel fibre addition, under combined axial load and bending. For this, an extensive survey was performed, and the main factors, which influence the column ductility, were pointed out. Then, parametric studies were done, aiming to establish the mode of influence of each factor. Based on these preliminaries studies, an experimental investigation, divided in two steps, was proposed. In the first part, twenty-six reinforced concrete columns and fourteen concrete columns were tested and three factors were analysed: the ratio of fibre addition, the transversal reinforcement ratio and the concrete compressive strength. The columns have 15 cm x 15 cm square cross section and were 50 cm high. They were tested under concentric load with displacement control. It was observed that all factors interfere in the columns\' ductility, and that, by adding fibre in the concrete, is possible to provide acceptable ductility index to high strength concrete columns. The load vs. column strain diagrams were studied and it was verified that for the first load peak, all the column cross section resists the axial load. Besides that, it was observed that the fibre addition improves the work together between the cover and the column core. Finally, several modifications to the concrete confinement model of Cusson and Paultre (1995) were proposed to allow this model to analyse the compressive behaviour of the confined concrete with or/not fibre addition. In the second part of the experimental program, fifteen reinforced concrete columns were tested under eccentric load. The effects of the load eccentricity, the ratio of steel fibre addition and the transversal reinforcement ratio on the column ductility were investigated. The columns have 15 cm x 15 cm square cross section and were 170 cm high. A pair of unidirectional hinges was design, which presented exceptional performance, transferring integrally the external applied moment to the columns. A most critical model of longitudinal reinforcement buckling and mass lost was observed. In addition, it was verified that when the values of all factors were increased, the column ductility was improved. Finally, a different distribution mode of the confinement pressure on the column cross section was observed, when combined axial load and bending is applied. Nevertheless, the confinement pressure on the compressive region of the column cross section is not modified.

A ervilha é um dos alimentos mais produzidos no mundo e, conseqüentemente, tem uma grande importância para a nutrição humana, sendo comercializada sob várias formas: fresca, seca, congelada e enlatada, necessitando de cozimento antes de ser consumida. Sendo assim, podem ocorrer alterações em sua composição durante esses processamentos. O presente trabalho teve como objetivos avaliar as mudanças ocorridas devido ao processamento na composição centesimal e no perfil de carotenóides em ervilhas frescas (tortas - com vagem comestível - e em grão), secas e enlatadas e relacionar esses dados com sua origem e safra. Foram analisados seis lotes de ervilhas tortas provenientes de duas regiões produtoras (cruas e cozidas por 5 minutos), três lotes de ervilhas frescas (cruas e cozidas por 7 minutos), dois lotes de ervilhas enlatadas (processadas e sua matéria-prima) e três lotes de ervilhas secas (cruas e cozidas por 35 minutos). A umidade em ervilhas tortas diferiu entre safras e regiões produtoras e em ervilhas em grão, aumentou após o cozimento em duas amostras e variou entre safras. O cozimento ocasionou perdas nos teores de Resíduo Mineral Fixo (RMF) em ervilhas em grão e secas. Em ervilhas enlatadas, o processamento causou aumento da umidade e RMF, devido à incorporação de água e sais. Os carotenóides encontrados foram a luteína, o β-caroteno e traços de violaxantina. O perfil de carotenóides em ervilhas tortas, em grão e secas não se alterou após o cozimento, já o enlatamento revelou um aumento aparente no teor de luteína em apenas um dos lotes estudados. Os teores de luteína e β-caroteno variaram entre as diferentes épocas de coleta de ervilhas tortas, em grão e secas, porém não foi observada variação entre as duas regiões produtoras de ervilhas tortas. Os teores de luteína variaram entre as matérias-primas dos diferentes fornecedores de ervilhas enlatadas. Apenas o β-caroteno possui atividade pró-vitamínica A, porém está presente em quantidade insuficiente para fazer das ervilhas fontes desse nutriente. / Pea is one of the world\'s most produced foods and therefore has great importance for human nutrition, being commercialized under different conditions: fresh, dried, frozen and canned, and further cooking is needed before being consumed. As a result, processing can cause some changes in its composition. The aim of the present work was to evaluate the changes in the centesimal composition and carotenoids profile of garden peas, snow peas, dry peas and canned peas due to processing and to compare these data according to geographic origin and crop. Six batches of snow peas from two different regions (raw and cooked for 5 min), three batches of garden peas (raw and cooked for 7 min), two batches of canned peas (processed and raw material) and three batches of dry peas (raw and cooked for 35 min) were analyzed. Water content in snow peas differed between crops and region and, in garden peas, it increased after cooking and varied between crops. Cooking caused losses in the ash content of garden and dry peas. In canned peas, processing increased water and ash contents due to absorption of water and salt. Lutein, β-carotene and traces of violaxanthin were identified in all samples. Carotenoids profile of snow, garden and dry peas did not change after cooking while canning caused an apparent increase in lutein contents only in one batch. Snow, garden and dry peas showed differences in lutein and β-carotene amount due to crops, though different regions revealed not to influence snow peas carotenoids content. The raw material from two suppliers of canned peas differed in their content of lutein. Only β-carotene is a pro-vitamin A carotenoid, however it was found in such small quantities that peas can not be considered source of this nutrient.

Finite element models were created in Abaqus 6.14 to characterize the rotational stiffness of shallowly embedded column-foundation connections. Scripts were programmed to automate the model generation process and allow study of multiple independent variables, including embedment length, column size, baseplate geometry, concrete modulus, column orientation, cantilever height, and applied axial load. Three different connection types were investigated: a tied or one part model; a contact-based model; and a cohesive-zone based model. Cohesive-zone modeling was found to give the most accurate results. Agreement with previous experimental data was obtained to within 27%. Baseplate geometry was found to affect connection stiffness significantly, especially at lower embedment depths. The connection rotational stiffness was found to vary only slightly with cantilever height for typical column heights. Results from varying other parameters are also discussed.

Despite the crucial role they play in transferring loads from the superstructure to the foundation, steel column-to-footing connections have received little attention in research. Though shallow embedded connections are typically characterized as pinned, studies have shown that they exhibit significant rotational stiffness. The objective of this thesis is to quantify the rotational stiffness of such connections. A method named the continuum model is developed by which the rotational stiffness of embedded connections may be calculated. Outputs from this model are compared with experimental data on steel connections embedded in concrete. The continuum model is shown to be capable of reasonably predicting the rotational stiffness of such connections. Results from the model were consistent with those of previous experimental studies that showed that embedment lengths greater than twice the column depth fail to significantly increase stiffness. Plots of rotational stiffness vs. embedment length developed from the continuum model are provided such that rotational stiffness may be calculated for any wide flange shape at any embedment length. Simplified equations provide a simpler way for engineers to estimate the same information.

This thesis aims to implement a combination of Linear Programming Column Generation and a Large Neighbourhood Search heuristic to solve scheduling problems. The resulting method is named Integer Programming Column Search (IPCS). For computational evaluation, the IPCS method is applied to the problem Prize-Collecting Job Sequencing with One Common and Multiple Secondary Resources generalised to parallel identical machines. The interest of combining exact procedures with heuristic approaches is quickly growing since scheduling problems have many and complex real-world applications. Most of these problems are NP-hard and therefore very challenging to solve. By using a combination of heuristic strategies and exact procedures, it can be possible to find high-quality solutions to such problems within an acceptable time horizon. The IPCS method uses a greedy integer programming column generating problem introduced in a previous work. This problem is designed to generate columns that are useful in near-optimal integer solutions. A difference to previously introduced method is that we here build a master problem, an Integer Programming Column Search Master (IPCS-Master). This is used to update the dual solution that is provided to the greedy integer programming column generating problem. The computational performance of the IPCS method is evaluated on instances with 60, 70, 80, 90 and 100 jobs. The result shows that the combined design encourage the generation of columns that benefit the search of near-optimal integer solutions. The introduction of an IPCS-Master, which is used to update the dual variable values, generally leads to fewer pricing problem iterations than when no master problem is used.

<p>Meiofauna, and especially marine nematodes are common in sediments around the world. Despite very wide ranging distributions in many nematode species, little is presently known about their dispersal mechanisms shaping these patterns. Rafting, and perhaps ballast water transport has been suggested as viable means for nematode long-range transport. On a much smaller scale other processes have been suggested for their dispersal. They generally include some form of passive suspension into the water column and later on a passive, haphazard settling back towards the bottom.</p><p>Small-scale phenomena in nematode dispersal were studied by conducting a series of studies at Askö field station, Trosa Archipelago, Baltic proper. Studied aspects were one case of macrofaunal influence on nematode dispersal rate, using an amphipod, <i>Monoporeia affinis</i> as disturbing agent, and three different studies on mechanisms related to settling. The experiments were conducted both in laboratory and field settings.</p><p>The amphipod <i>Monoporeia affinis</i> did not exert any influence on the dispersal rate in the nematodes. The nematode dispersal was only an effect of time, in the aspect that the more time that past, the more nematodes dispersed from their place of origin. The settling experiments revealed that nematodes do have an active component in their settling behaviour, as they were able to exert influence on the spot where they were to settle. They were able to choose settling spot in response to the food quality of the sediment. It also became evident that contrary to common belief, nematodes are able to extend their presence in the water column far beyond the times that would be predicted considering settling velocities and hydrodynamic conditions alone.</p>

<p>Förorenat dagvatten från Stena Gotthards metallåtervinningsanläggning i Eskilstuna har filtrerats genom kolonner innehållande två olika adsorbenter, torv och furubarksflis. Torv är en organisk jordart som främst används som bränsle och furubarksflis är en biprodukt från skogsindustrin. Båda filtermaterialen är relativt billiga och finns i stora kvantiteter i Sverige. Filtermaterialen har visat sig ha varierande kapacitet att adsorbera metaller i vatten på grund av själva materialet samt vattnets sammansättning. Resultatet från den här studien visar att av de två undersökta filtermaterialen så har furubarksflis störst kapacitet att reducera bly, koppar och zink från det specifika dag vattnet.</p> / <p>Polluted storm water from a metal recycling industry has been filtrated through columns that contained two different adsorbents, peat and pine bark. Peat is an organic soil, mainly used for energy production, and pine bark, a by-product from the forest industry. In Sweden, there are a lot of resources of peat as well as pine bark. Used as filter materials, they are relatively cheep and, like other kinds of filtermaterial used as adsorbents, they have varied capacity to adsorb metals in water. The capacity for the filter materials to adsorb metals depends on the physical structure and chemical contents of the peat and pine bark as well as the water metal composition. Results from this study show that pine bark had the highest adsorption capacity to reduce copper, lead and zinc from the specific storm water.</p>