O aproveitamento de proteína de pescado como coprodutos do processo de industrialização, constitui-se em uma alternativa para a elaboração de produtos com elevada qualidade nutricional. A carne mecanicamente separada (CMS), produzida a partir de carcaças do descarte do processamento de tilápia híbrida vermelha (CMSV), Oreochromis niloticus var. Red Stirling e de tilápia preta (CMSP), Oreochromis niloticus, foram caracterizadas física, química, microbiológica e sensorialmente. Em um primeiro estudo avaliou-se a eficiência de dois tipos de equipamentos de extração mecânica da CMS, rosca- sem-fim e cinta-tambor. Posteriormente, avaliou-se a qualidade da CMS congelada durante 90 dias de armazenamento. Em seguida avaliou-se os atributos sensoriais de cor, odor e aparência da CMSV e CMSP congelada. Para a avaliação do sabor da CMS, foi adicionado ao molho de tomate com CMSV armazenada por 15 e 90 dias e a aceitação avaliada por consumidores. Foi realizado um estudo para avaliação das características de funcionalidade da CMS reestruturada da tilápia híbrida vermelha. O separador tipo rosca-sem-fim apresentou melhor rendimento de extração e controle da temperatura do processo, quando comparado ao separador do tipo cinta-tambor, embora ambos os processos tenham permitido a obtenção de CMS com teores de umidade, proteína e lipídeo adequados para o processamento de coprodutos. A avaliação da vida útil indicou que coprodutos da tilápia híbrida vermelha (CMSV) e tilápia preta (CMSP) apresentaram padrões microbiológicos, valores de pH e oxidação lipídica aceitáveis ao longo do estudo, mesmo apresentado uma descoloração ao longo do armazenamento. A avaliação sensorial para o estabelecimento da vida útil (teste de diferença do controle com provador treinado) foi realizada em períodos até 90 dias. Aos 15 dias de armazenamento, os provadores detectaram diferença significativa, porém o limite sensorial estabelecido pelos provadores (moderadamente diferente do controle) foi atingido aos 60 dias para a CMS da tilápia preta e aos 90 dias para a CMS de tilápia vermelha. A aceitação teve boa resposta, porém a intenção de compra apresentou queda de 19% para o molho adicionado de CMS estocada durante 90 dias. A CMSV é uma matéria prima, com elevado teor proteico (12%) e elevado teor lipídico (15%) e pode ser utilizada para elaboração de diferentes coprodutos. Foi possível obter produto reestruturado com boa funcionalidade tecnológica com adição de 100% de CMS de tilápia híbrida vermelha, o que demonstra a viabilidade de sua utilização, onde apresentaram respostas satisfatórias de rendimento, capacidade de retenção de água e força de penetração no reestruturado. Conclui-se que a CMS das variedades de tilápia estudadas representam um coproduto de qualidade a ser aproveitado pela indústria. Além de contribuir para para fornecer dados, junto a outros trabalhos, para se criar um padrão de identidade e qualidade da CMS de pescado, o que é de suma importância para o controle de qualidade da indústria processadora do coproduto. / The use of fish protein resulting from the industrial process constitutes an alternative to the development of co-products with nutritional quality. Mechanically recovered meat (MRM), produced from carcasses of Red hybrid tilapia, Oreochromis niloticus var. Red Stirling and black tilapia Oreochromis niloticus were characterized in terms of physical, chemical, microbiological and sensory aspects. The first study evaluated the efficiency of two mechanical extraction devices of MRM, the screw type and the belt and drum type. Later assessed the quality of frozen MRM for 90 days of storage. Then it was evaluated the sensory attributes of color, odor and appearance of defrozen MRM. The resulting MRM was used in the development of a tomato sauce and its acceptance with consumers was analyzed. A performance study of MRM restructured of red hybrid tilapia was conducted. The worm screw-type separator presented better extraction yield when compared to belt-drum type separator, but both processes allowed obtaining MRM with levels of moisture, protein and lipids suitable for processing co-products. Both MRM presented microbiological and oxidative stability after 90 days of storage. The sensory analysis of control difference for up to 90 days showed significant difference to that at 15 days of storage. The team of tasters set the value 4 (appearance, color and odor moderately different from the control) as limiting MRM shelf life to 60 days for MRM of the Nile tilapia and 90 days for MRM of the red tilapia. The tomato sauce with the addition of tilapia formulated with MRM of the red tilapia stored for 15 and 90 days was well accepted by consumers, but purchase intent dropped 19% for the product obtained from MRM with 90 days of storage. The MRM from the red hybrid tilapia is a raw material with high protein content, average 12%, and high lipid content, average 15%, and can be used to prepare different co-products of tilapia. It was possible to obtain restructured product with addition of 100% of MRM from the red hybrid tilapia with good processing characteristics, which shows viability of production with satisfactory responses of performance, water retention capacity and penetration force of restructured fish meat. We conclude that the CMS of the studied tilapia varieties represent a quality co-product to be used by the industry. Besides contributing to to provide data , along with other works , to create a standard of identity and quality of fish CMS , which is of paramount importance for the quality control of the co-product processing industry.

In der Dissertation wurden Nanokomposite mit unterschiedlichen Kautschuken (HNBR, EPDM, MAH-g-EPDM) als Basismaterial sowie diversen modifizierten Schichtsilikaten als Füllstoff hergestellt und charakterisiert. Untersucht wurden die sich ausbildenden Strukturen bzw. die Morphologie (Aggregation, mögliche Orientierungen), die mechanischen Eigenschafte (Verstärkungswirkung) sowie die Füllstoff-Füllstoff-Wechselwirkungen und die Polymer-Füllstoff-Wechselwirkungen.

Baigiamajame magistro darbe atliekami eksperimentiniai gelžbetoninių sijų, sustiprintų pneumatiniu montažiniu pistoletu mechaniškai tvirtinama anglies pluošto juosta, elgsenos tyrimai, nagrinėjama jungių skaičiaus ir išdėstymo įtaka sijos elgsenai. Darbą sudaro: įvadas, trys pagrindiniai skyriai, pasiūlymai ir išvados, literatūros sąrašas. Įvade aptariama tiriamoji problema, darbo aktualumas ir naujumas, pristatomas darbo objektas, formuluojami tikslai ir uždaviniai, pateikiama tyrimų metodika. Pirmajame skyriuje pateikiamos bendros žinios apie sijų stiprinimą, apžvelgiama stiprinimo metodų raida, aptariamos statybiniams kompozitams gaminti naudojamos medžiagos ir aprašomi populiariausi metodai, naudojami statybiniais kompozitais sustiprintų sijų skaičiavimui. Antrajame skyriuje plačiau aptariamas sluoksnių skaičiavimo metodas, atliekama jo parametrinė analizė. Trečiajame skyriuje plačiai aprašomas bandinių paruošimas ir jų bandymo metodika, pateikiami eksperimentinių tyrimų rezultatai, jie palyginami su teoriniais skaičiavimais bei kitų autorių gautais rezultatais. Darbo pabaigoje pateikiami sijų stiprinimo pneumatiniu montažiniu pistoletu mechaniškai tvirtinama anglies pluošto juosta pasiūlymai, formuluojamos išvados. Darbo apimtis – 69 p. teksto be priedų, 33 paveikslai, 5 lentelės, 32 bibliografiniai šaltiniai. / This thesis presents the analysis based on experimental testing of reinforced concrete beams, strengthened by mechanically fastened fiber reinforced polymer strips, when high pressure air powered pinner was used to fasten the strips. The influence of the number and arrangement of fasteners is investigated. Thesis consists of introduction, three main chapters, recommendations and conclusions, literature list. The introduction presents an overview, objectives, scope, methodology and significance of thesis. The first chapter shows the development of beam strengthening, introduces composite materials and methods used for calculating beams strengthened using FRP strips. In the second chapter the chosen calculation method is described in detail and its parametric analysis is performed. Third chapter gives a detailed description on the test specimen preparation and the methodology of testing. Experimental results and their comparison with theoretically obtained values and values obtained by other researchers are given here. The recommendations on the technology of strengthening the beams using mechanically fastened fiber reinforced polymer strips are given and the conclusions are drawn. Thesis contains 69 pages. There are 33 pictures, 5 tables and 32 references in the thesis.

Molecular recognition plays an essential role in the self-assembly and self-organisation of biological and chemical systems alike—allowing individual components to form complex interconnected networks. Within these systems, the nature of the recognition and reactive processes determines their functional and structural properties, and even small changes in their identity or orientation can exert a dramatic effect on the observed properties. The rapidly developing field of systems chemistry aims to move away from the established paradigm in which molecules are studied in isolation, towards the study of networks of molecules that interact and react with each other. Taking inspiration from complex natural systems, where recognition processes never operate in isolation, systems chemistry aims to study chemical networks with the view to examining the system-level properties that arise from the interactions and reactions between the components within these systems. The work presented in this thesis aims to advance the nascent field of systems chemistry by bringing together small organic molecules that can react and interact together to form interconnected networks, exhibiting complex behaviour, such as self-replication, as a result. Three simple building blocks are used to construct a network of two structurally similar replicators and their kinetic behaviour is probed through a comprehensive kinetic analysis. The selectivity for one of the recognition-mediated reactive processes over another is examined within the network in isolation as well as in a scenario where the network is embedded within a pool of exchanging components. The interconnected, two-replicator network is examined under far-from-equilibrium reaction-diffusion conditions, showing that chemical replicating networks can exhibit signs of selective replication—a complex phenomenon normally associated with biological systems. Finally, a design of a well-characterised replicator is exploited for the construction of a network integrating self-replication with a another recognition-directed process, leading to the formation of a mechanically-interlocked architecture—a [2]rotaxane.

Master of Science / Department of Civil Engineering / Stacey Kulesza / In Kansas, mechanically stabilized earth (MSE) retaining walls are typically backfilled with coarse aggregate. Current backfill material testing procedures used by the Kansas Department of Transportation (KDOT) utilize on-site observations for construction quality assurance and the American Association of State Highway and Transportation Officials standard T 288-12 (“Standard Method of Test for Determining Minimum Laboratory Soil Resistivity”). AASHTO T 288-12 is designed to test a soil sample’s electrical resistivity (ER) that correlates to its corrosion potential. However, the test, based on material passing through a No. 10 sieve, is inappropriate for coarse aggregate typically used by KDOT as the aggregate will be retained on a No. 10 sieve and potentially leads to over-conservative designs. However, ER imaging provides a two-dimensional (2D) profile of bulk ER of backfill material, thereby yielding more information regarding backfill uniformity compared to traditional sampling. The objective of this study was to characterize bulk ER of in-place MSE wall backfill aggregate. In this study, MSE walls selected by KDOT were tested using ER imaging during construction to determine bulk ER of the backfill. Variations within backfill ER may be a result of varying aggregate material, inclusions of fines, thoroughness of compaction, and the presence of water. ER imaging was used on five walls: four MSE walls and one gravity retaining wall that contained no reinforcement. One MSE wall contained metal reinforcement, while the other four walls contained geosynthetic. The ER imaging field method produced a 2D profile that depicted ER uniformity for bulk analysis. A post processing algorithm was generated to remove the subjective nature of the ER imaging results. The program determines the bulk ER based upon the ER imaging results. These results indicate that the laboratory analysis of AASHTO T 288-12 under-estimates the bulk ER of in-situ backfill material. Identification of a material’s bulk ER will help characterize the ER of aggregates in a complementary KDOT project. Results of this study will be used to recommend an in-situ test method for aggregate used by KDOT.

La prédétermination de la hauteur de départ des avalanches représente un défi majeur pour l'évaluation du risque en montagne. Cette hauteur constitue en effet un ingrédient d'entrée important des procédures de zonage et de cartographie du risque. Dans cette thèse, nous présentons un formalisme rigoureux dans lequel les distributions de hauteur de départ d'avalanche sont exprimées à travers un couplage des facteurs mécaniques et météorologiques. Le critère de stabilité du système plaque - couche fragile est étudié en utilisant une analyse mécanique par éléments finis prenant en compte l'hétérogénéité spatiale des propriétés mécaniques. Considérant qu'une avalanche ne peut se produire que si la hauteur de chute de neige dépasse une hauteur critique correspondant au critère de stabilité, les distributions de hauteur de départ obtenues à partir du modèle mécanique sont couplées avec la distribution des chutes de neige extrêmes sur 3 jours. Nous montrons que ce modèle couplé est capable de reproduire des données de terrain de 369 avalanches naturelles de plaque à La Plagne (France). Non seulement la queue de la distribution en loi puissance, correspondant à des épaisseurs de plaque élevées, mais aussi le corps de la distribution pour les plaques moins épaisses, sont bien reproduits par le modèle. Les avalanches petites à moyennes semblent être essentiellement contrôlées par la mécanique, tandis que les grosses avalanches et l'exposant de la loi puissance associé, sont influencés par un couplage mécanique - météorologique fort. Par ailleurs, nous démontrons que la distribution obtenue est fortement dépendante de l'espace, et, en utilisant les processus max-stables permettant une interpolation spatiale rigoureuse, notre modèle couplé est utilisé pour obtenir des cartes de hauteur de départ d'avalanche pour différentes périodes de retour sur l'ensemble des Alpes françaises. / The evaluation of avalanche release depth distributions represents a major challenge for hazard management in mountaineous regions. This depth constitutes an important input ingredient of hazard mapping procedures. This PhD thesis presents a rigorous formalism in which these distributions are expressed through a coupling of mechanical and meteorological factors. The stability criterion of a layered snowpack is investigated using a finite-element analysis accounting for the spatial heterogeneity of weak-layer mechanical properties. Considering that an avalanche can occur only if the snowfall depth exceeds a critical value corresponding to a stability criterion, release depth distributions obtained from the mechanical model are coupled with the distribution of 3-day extreme snowfalls. We show that this coupled model is able to reproduce field data from 369 natural slab avalanches in La Plagne (France). Not only the power-law tail of the distribution, corresponding to large slab depths, but also the core of the distribution for shallow slab depths, are well represented. Small to medium-sized avalanches appear to be controlled mainly by mechanics, whereas large avalanches and the associated power-law exponent, are influenced by a strong mechanical-meteorological coupling. Finally, we demonstrate that the obtained distribution is strongly space dependent, and, using max-stables processes allowing a rigorous spatial interpolation, our coupled model is used to obtain release depth maps for given return periods in the whole French Alps.

Friction Stir Welding (FSW) is a rapidly growing solid state welding process and has been a proven method for welding high strength aluminium alloys which were formerly not recommended for joining by conventional fusion welding methods. Based on the information acquired from previous studies, to obtain a defect free Friction Stir (FS) weld with suitable strength, three basic requirements need to be fulfilled (i) Filling of the cavity created behind the tool pin during its traverse and ensuring satisfactory contact of filled material with newly generated surface (on advancing side trailing edge of the pin) (ii) Disrupting and distributing the oxide layer at the initial weld interface (iii) Adequate level of mixing of both side material (Adjacent and Retreating side) in similar welding. In the case of dissimilar welding mixing is desired in controlled amount (to prevent or curtail formation of intermetallics) depending on material combination. Failure to achieve the first precondition results in void. Second and third precondition are interconnected for similar FSW as adequate mixing in weld helps in disruption and distribution of oxide layer at initial weld interface. Failure to achieve this, results in Joint Line Remnant (JLR). Metal to metal contact cannot be established due to the presence of JLR (aligned oxide particles) and subsequently initial interface is left unwelded which deteriorate the static and dynamic strength of friction stir welds. The problem aggravates while friction stir welding materials with tenacious contaminant layer. Therefore, appropriate stirring (which entails large deformation and mixing) of initial weld interface is essential for successful FS welds. Hence, process aspects assisting mixing of adjacent (Advancing and Retreating side) materials need to identified and studied, which are missing in former studies. Experiments are conducted with classical FS tool (possessing frustum shaped/tapered circular pin) to analyse the effect of welding parameters (tool rotation speed, traverse speed, plunge depth, tool tilt and tool position w.r.t initial interface) and tool runout by changing these parameters over a range. Tool rotation speed, traverse speed, plunge depth and tool position with initial interface are changed continuously and tool tilt and tool runout are changed in discrete steps. Tool geometry is considered to be a prime parameter controlling the magnitude of mixing, as interaction of rotating tool with initial abutting base metal interface makes the process mechanism complex, unlike other solid state welding process, namely forge welding, diffusion welding, friction welding, explosive welding, ultrasonic welding and roll bonding. Furthermore, due to asymmetric nature of material flow in FSW process, the material located in different locations with respect to the tool is subjected to different levels of deformation. For this purpose experiments have been carried out to analyse the effect of different tool geometrical aspects on level of mixing and material flow. On the other hand, visualizing flow and mixing in metals is debatable as insertion of marker material in the weld line can alter the nature of material flow in the weld due to different material flow characteristics of the base and marker materials and introduction of additional interfaces. Further, using dissimilar materials for flow studies cannot be considered for comparison with similar friction stir welds as their flow properties are different. Therefore, an alternate experimental strategy is devised in these studies using physical modelling approach which is effective and helps in identifying and quantifying mixing observed under different tooling and process conditions. In the present investigation, plasticine of primary colours is adopted and the hue attribute of colour is used to study and quantify intermixing. Yellow and Blue plasticine are placed on advancing and retreating sides respectively. The degree of mixing is indicated by the intensity of generated green. Digital images of the cross section in weld nugget region are taken. To obtain hue component of these digital images the RGB color-maps are converted to HSV color-maps. Overall, these studies help in formulating the guidelines which are useful during tool design, and administering the process to obtain a defect free well mixed welds. Based on the experimental results following conclusions are derived. 1. Following process aspects: tool geometry, interface offset, tool rotation and tool runout demonstrate a significant impact on material mixing and breaking and dispersion of initial interface in weld nugget. Tool tilt, plunge depth, tool traverse exhibit negligible effect on degree of mixing. 2. Increase in tool rotation speed (with other parameters fixed) improves mixing substantially but can be increased to a certain limit after which voids emerge due to loss of weld nugget material in the form of flash. 3. Reducing the weld pitch (i.e. increasing tool rotation speed for a given tool traverse speed) reduces the size of the weld nugget and vice versa. Tool traverse speed largely affects advancing side material and rotation speed affects retreating side material. Therefore, for higher weld pitch advancing side material (yellow plasticine) dominates the weld nugget, whereas for lower weld pitch retreating side material (blue plasticine) dominates the weld nugget. 4. The extended macro-structural feature commonly observed in FS welds occurs under influence of plunge depth. Consequently, this macro-structural feature serves as the demarcation point between shoulder affected and pin induced material flow in FS weld. 5. The degree of mixing and subsequent elimination of JLR, improves, when original interface is offset on the advancing side w.r.t tool axis for all the tools investigated in the present study. Triangular and square pin generate larger pin induced mixing which intensifies further with interface on advancing side, indicating tools with such profiles to possess larger safe zone with better mixing characteristics 6. At zero interface offset with all the process parameters fixed, tapered triangular and square pin profile tools produce welds with maximum mixing. For pins with faces, material is transported in lumps around the pin. The size of lump increases with lesser number of faces on pin. Material in the vicinity of the pin experiences spinning/whirling movement. The volume of material experiencing spinning in a single tool revolution depends on (a) weld-pitch (lesser volume of material for smaller weld pitch and vice versa) and (b) number of faces on the pin (lesser volume of material for greater number of faces and vice versa). Therefore, circular pin which can be considered to be made of infinite faces, spinning of material occurs at micro level for relatively smaller weld pitch. 7. For classical FS tool (tapered circular/frustum shape), there exists an optimum ratio (shoulder diameter/pin diameter) situated between 2.7 to 3.6 to produce void free well mixed welds. Tools with ratio of 2.7 and below possess a tendency to produce welds with void but with better mixing in weld region. Tools with ratio of 3.6 and above possess a tendency to produce void free welds but with poor mixing in weld region. Voids appear and grow under following circumstances (a) with increase in pin diameter (for a fixed shoulder diameter), (b) with decrease in shoulder diameter (for a fixed pin diameter), (c) with decrease in pin taper (for a fixed shoulder diameter and top diameter of pin). Pin length has no effect on void formation. However, it is obvious, length of root defect increases with decrease in pin length. The tooling guidelines established in this study through plasticine work can be extended to metallic friction stir welds of various thickness plates by proportionately increasing or decreasing the tool dimensions as long as they fall in the recommended range. 8. Smaller pin diameter tools exhibit higher optimum weld pitch (but with lower degree of mixing) when compared to larger pins (but with higher degree of mixing). Optimum weld pitch represents weld pitch resulting in void free welds. Consequently, tools with higher optimum weld pitch help in welding at a better rate. 9. Tool runout is replicated through tools with eccentric pins. It is interesting to note that, all the tools with pin eccentricities do not assist in mixing but tools with only certain eccentricities (0.3 and 0.6mm assisted in mixing in the present investigation). It implies that tool runout of certain values facilitate mixing in weld. On the other hand density of void increases with eccentricity of pin/tool runout. 10. In dissimilar FSW investigated with plasticine A, B, C and D possessing different flow stresses (flow stresses ascending in the order of A, B, C and D) and strain rate sensitivity of 0.24, 0.22, 0.19 and 0.18 respectively, following inferences are drawn (i) For combination A and B, weldability improves when plasticine B is on Advancing Side (AS) and A is on Retreating Side (RS). The level of mixing also improves when interface is on AS (w.r.t tool axis) for this handedness. On the contrary, severe discontinuities emerge when plasticine B is on RS and A is on AS, especially when interface is closer to the tool pin axis. (ii) For combination A and C, weldability improves when C is on AS and A is on RS. The level of mixing also enhances when interface is on AS (w.r.t tool axis) for this handedness. (iii) For combination A and D, joining is poor for both the handedness. However, nature of defect is different in both the combinations. Cracks are observed when A is located on AS and voids emerge when D is located on AS. On the other hand, placing A on AS results in weld thinning. (iv) For combination B and C, there is no appreciable change in terms of weldability and level of mixing. Both the handedness in this combination yielded fairly similar results. (v) For combination B and D, though discontinuities do not emerge with change in handedness, mixing in weld improves when B is on AS unlike to its location on RS. (vi) For combination C and D, there is no appreciable change in terms of defect formation and level of mixing with change in handedness. Both the handedness in this combination yield fairly similar results.

Grande percentagem do território brasileiro é coberta por solos finos (% passando peneira # 200 > 50%), geralmente de origem tropical, que poderiam ser classificados como solos de baixa capacidade de drenagem. Estes solos não atendem às recomendações técnicas para solos de aterro de estruturas reforçadas, conforme exigido pela AASHTO e BS 8006. Neste trabalho foi avaliado experimentalmente um dos parâmetros mais importantes de projeto de Terra Armada, que condiciona o mecanismo de transferência de carga, o coeficiente de atrito aparente solo-fita metálica (f*). Foi avaliada a influência das características dos solos para as classes de solos estabelecidas pela NBR 9286/86 para o caso de fitas metálicas, e, dos critérios que sustentam o uso de fitas poliméricas, sob diversas tensões verticais atuantes nas fitas, simulando o efeito da profundidade. As informações foram obtidas através de ensaios de arrancamento de fitas metálicas e poliméricas realizados em laboratório e depois comparadas aos resultados teóricos da norma e àqueles preconizados para o uso de fitas poliméricas. Os ensaios realizados com as fitas em solo não convencional 1 e em areia mal graduada, mostraram que para profundidades equivalentes a tensões verticais até 50 kPa, os dois tipos de inclusões possuem valores de coeficiente de interação com o solo maiores que a unidade, isso tornaria razoável o seu uso sob o ponto de vista deste parâmetro e nas condições da realização dos ensaios, quando comparado com a norma, e com os critérios que sustentam o uso das fitas poliméricas em técnica de solo armado. No entanto, para maiores profundidades, a interação apresenta uma tendência de diminuição. O solo não convencional 2 valores da interação muito baixos. Foram instalados strain gages ao longo do comprimento das fitas para monitoramento dos esforços no maciço. Nota-se que esforços elevados ocorreram nas regiões mais próximas do ponto de aplicação da força de arrancamento. / A large percentage of Brazil\'s territory is covered with fine tropical soil (50% passing #200) which can be classified as soils with low drainage capacity. These soils do not meet the technical recommendations for backfill of reinforced soil structures by AASHTO and BS 8006. This paper presents the result of an experimental evaluation of one of the most important design parameters of mechanically stabilized earth with concrete wall facing. The apparent friction coefficient of soil-steel strips and soil-polymeric strips is the project parameter. Also was evaluated the influence of soil characteristics for soil types listed by the NBR 9286/86 for metal strips and for the criteria that support the use of polymeric strips. The evaluation included the application of different vertical stresses on the strips simulating the effect of depth. The information obtained from pullout tests performed in laboratory was compared to the standard theoretical values and design values for polymeric strips. Tests performed on strips in nonconventional soil (1) and poorly graded sand showed that at depths equivalent to vertical stresses up to 50 kPa the two types of inclusions have coefficients of interaction greater than unity, which appears reasonable. Therefore, such soils can be used as backfill soils in the conditions tested and at equal or lesser stress levels. Nonconventional soil (2) showed low value of the friction coefficient. The strain gages installed along the length of the strips recorded the distribution of tensile stress in pull-out tests. Higher tensile stress was recorded by the gages nearest the point of application of the pull-out force.

The production and use of protein hydrolysates, derived from animal and vegetable sources in specific formulations is an area of growing interest. Protein hydrolysates can be obtained mainly by three methods: alkaline hydrolysis, enzymatic hydrolysis and acid hydrolysis. However, enzymatic hydrolysis shows to be more beneficial, and with this purpose various enzymes from different sources are used in order to obtain protein rich hydrolysates. Three proteolytic enzymes called Papaína®, Flavourzyme® and Protamex® were used for hydrolysis of mechanically separated meat MSM and manually deboned chicken carcass MDC. The hydrolysis occurred in a thermostatic bath with controlled temperature, time and pH, specific to each of the three enzymes used. Proximal composition of raw materials and lyophilized hydrolysates obtained was performed. Also were performed control analysis of hydrolysis such as degree of hydrolysis, protein, total solids, ash and characterization of amino acid hydrolysates. The results were evaluated by analysis of variance and Tukey test. Protein hydrolysates obtained from MSM and MDC had high protein content characterizing them as a promising raw material in the formulation of special diets. The highest degree of hydrolysis with MCS was obtained with Papaína, and the most efficient MDC enzyme in the enzymatic hydrolysis was Papaína, followed by Protamex and Flavourzyme. The hydrolysates obtained from the MCS with Papaína obtained higher protein and soluble solids content and lower ash content when compared to other hydrolysates with Protamex and Flavourzyme. For the raw MDC, the highest levels of proteins were found in the hydrolyzate obtained with Papaína, soluble solids did not vary between Papaína and Protamex, but the enzyme Flavourzyme presented a smaller percentage of soluble solids (p <0.05) than the other two enzymes. The highest concentration of ash from the hydrolysates obtained from MDC with Protamex and Flavourzyme (6.75% to 7.97%) is the result of pH adjustment during hydrolysis. The amino acid composition of the hydrolysates demonstrates that both CMS and CMD derived from Papain obtained a composition closer to what is recommended by the control authorities. The functional properties of the hydrolysates are highly dependent on the degree of hydrolysis. The protein solubility increased with higher degree of hydrolysis and the hydrolyzate with highest solubility was MCS obtained from Papaína. The higher water retention capacity was presented by the enzyme hydrolyzate obtained with Flavourzyme on MSM and this property is inversely proportional to the degree of hydrolysis, such as the ability to retain oil which was higher with Flavourzyme on both raw materials. The emulsifying capacity was also higher with Flavourzyme on MSM, since this property also depends on the degree of hydrolysis. Therefore, based on the results, enzymatic hydrolysis becomes a useful tool for processing meat based raw materials. / A produção e a utilização de hidrolisados proteicos, oriundos de fontes animais e vegetais, em formulações específicas é uma área de crescente interesse. Os hidrolisados proteicos podem ser obtidos basicamente por três métodos, hidrólise alcalina, hidrólise enzimática e a hidrólise ácida. Porém, a hidrólise enzimática apresenta-se mais benéfica, e com este intuito várias enzimas das mais diferentes fontes são utilizadas, com a finalidade de obter hidrolisados proteicos, ricos em proteínas. Neste estudo foram utilizadas três enzimas proteolíticas denominadas de Papaína®, Flavourzyme® e Protamex® para a hidrólise de carne mecanicamente separada (CMS) e carcaça manualmente desossada (CMD) de frango. A hidrólise ocorreu em banho termostatizado com temperatura, tempo e pH controlados e específicos para cada uma das três enzimas utilizadas. Foi determinada a composição proximal das matérias-primas e dos hidrolisados liofilizados obtidos, também foram realizadas análises de controle da hidrólise como grau de hidrólise, teores de proteínas, sólidos totais, cinzas e caracterização de aminoácidos dos hidrolisados. Os resultados foram avaliados por análise de variância e teste de médias de Tukey. Os hidrolisados proteicos obtidos da CMS e da CMD de frango apresentaram alto conteúdo proteico caracterizando-se como uma matéria-prima promissora na formulação de dietas especiais. O maior grau de hidrólise com a CMS foi obtido com a Papaína, e para a CMD a enzima mais eficiente na hidrólise enzimática foi a Protamex seguida da Papaína e da Flavourzyme. Os hidrolisados obtidos a partir da CMS com a Papaína obtiveram maior teor proteico, de sólidos solúveis e menor teor de cinzas quando comparados com outros hidrolisados obtidos com a Flavourzyme e a Protamex. Para a matéria prima CMD, os maiores teores de proteínas foram encontrados no hidrolisado obtido com a Papaína, os sólidos solúveis não variaram entre a Papaína e Protamex, porém a enzima Flavourzyme apresentou um percentual de sólidos solúveis menores (p<0,05) que as outras duas enzimas. A maior concentração de cinzas dos hidrolisados provenientes da CMD obtidos com a Flavourzyme e com a Protamex (6,75% a 7,97%) é decorrente do ajustamento do pH durante a hidrólise. A composição de aminoácidos demonstra que os hidrolisados oriundos tanto da CMS como da CMD obtidos da Papaína possuem uma composição mais próxima da recomendada pelos órgãos de controle. As propriedades funcionais dos hidrolisados são altamente dependentes do grau de hidrólise. A solubilidade proteica aumentou com o aumento do grau de hidrólise e o hidrolisado que apresentou maior solubilidade foi com a CMS e com a papaína como enzima. A maior capacidade de retenção de água foi apresentada pelo hidrolisado obtido com a enzima Flavourzyme na CMS, e esta propriedade é inversamente proporcional ao grau de hidrólise. Da mesma forma a capacidade de retenção de óleo foi maior para a Flavourzyme, nas duas matérias-primas utilizadas. A capacidade emulsificante também foi maior para a Flavourzyme na CMS, já que esta propriedade também depende do grau de hidrólise. Assim, com base nos resultados obtidos conclui-se que a hidrólise enzimática torna-se uma ferramenta bastante útil na transformação das matérias-primas cárneas.

Cette thèse étudie le comportement de remblais en sol renforcé lors du passage de trains par simulation numérique. Il s'agit de déterminer si les trains à grande vitesse ont un impact particulier sur ce type d'ouvrage. Après un état de l'art des remblais en sol renforcé et de la modélisation numérique de problèmes ferroviaires, les résultats du chargement harmonique d'un remblai expérimental en Terre Armée sont analysés. Ils montrent que les valeurs des tractions dans les armatures, des contraintes et déplacements dans le massif dépendent de la fréquence de la sollicitation, c'est-à-dire de la vitesse de passage du train. On construit un modèle 3D aux éléments finis pour reproduire cette expérience. Il permet de retrouver les valeurs expérimentales avec une bonne précision, en mettant en avant l'importance du choix des lois de comportement du sol, du parement et des armatures. Ce modèle avec ses paramètres est alors utilisé pour discuter du comportement local de l'interface armature/remblai au cours d'un chargement harmonique en régime établi. Le confinement varie beaucoup le long des armatures supérieures au cours du chargement dynamique, tandis que les tractions sont peu affectées par le chargement dynamique. Cependant, malgré ces variations au cours du temps, la stabilité de l'interface reste peu affectée par rapport au cas d'un chargement statique. Un second modèle a été développé pour représenter un remblai de taille plus importante, en utilisant la modélisation multiphasique et en utilisant un repère mobile pour prendre en compte le déplacement du train. Les aspects théoriques et l'implémentation de ce modèle dans le code CESAR-LCPC sont détaillés. On l'utilise pour effectuer une étude tri-dimensionnelle d'un remblai renforcé. Elle met en évidence la faible influence de la vitesse de la charge sur la réponse de l'ouvrage, dans le cas d'un remblai rigide ayant des caractéristiques tirées du remblai expérimental. Dans le cas d'un remblai moins rigide, la vitesse d'un TGV peut s'approcher de la vitesse des ondes de cisaillement dans le massif avec des conséquences significatives au sein de la structure. Finalement, les valeurs expérimentales et les deux modèles numériques développés présentent les mêmes tendances : l'effet dynamique du passage du train a pour conséquence une augmentation des déplacements et une variation du confinement des armatures, tandis que les niveaux de traction sont peu affectés par la charge, ce qui nous incite à conclure que la vitesse du train n'est pas significativement pénalisante sur la stabilité des remblais pour les paramètres issus de l'analyse du remblai expérimental. Toutefois, ces résultats dépendent fortement de la géométrie de la structure, de la façon de modéliser le train, des lois de comportement et des valeurs des paramètres retenus pour le sol, le parement et l'interface sol/armature / This study focuses on the numerical modeling of the Mechanically Stabilized Earth (MSE) walls behavior under High Speed Train (HST) loading. First, the state of the art in reinforced earth as well as in railway dynamics modeling is analyzed. Then we present results coming from the testing of a one-scale reinforced embankment submitted to harmonic loading. They indicate that tensile forces in reinforcements, stresses and displacements depend on loading frequency which is related to train speed. One proposes a 3D Finite Element Model (FEM) in order to numerically reproduce this experimentation. The numerical results fit reasonably well with the experimental ones, highlighting the great importance of the choice of the constitutive law for the soil, reinforcement and facing. The same model is used to locally investigate the soil/reinforcement interface behaviour during a harmonic loading in steady-state. The confining pressure presents significant variations along the reinforcement strip during the dynamic loading while tensile forces are less affected by the load. Nevertheless, the global interface stability remains acceptable compared to a static load. A second numerical model is proposed, which represents a bigger embankment. The multiphase model is used to represent the reinforced soil and moving coordinates are used to take into account the moving train. Theoretical developments of this model and its implementation into CESAR-LCPC FEM code are detailed. The results indicate that the train speed does not play a big role in the overall response of the structure, in the case of a stiff reinforcement comparable to the experimental one. If the embankment is weaker, the HST speed may be close to shear waves speed within the soil, which has significant consequences into the structure, particularly on the stability of the soil/reinforcement interface. Globally the experimental results and those coming from both numerical models present the same trends: the dynamic effect coming from the train passing leads to the in-crease of displacements and confining pressure close to the highest strips, while tensile forces are less affected by the load. This leads us to the conclusion that the train speed does not have a significant effect on the stability of MSE walls, at least for embankments having similar parameters than the experimental one. However these results strongly depend on the embankment geometry, the way to model the train and the parameters and constitutive laws chosen for the soil, the soil/reinforcement interface and the facing