939 resultados para Bending crack


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This anthropological research has as main goal to grasp the meanings and perceptions - mode of subjectivity - of crack users in relation to the proposals of Therapeutic Communities (TC) of religious character. The work emphasizes the analysis of Therapeutic Communities of Rio Grande do Norte state, studying a particular organization, called Anzóis da Dor. I intend to analyze qualitative data, focusing on an analysis of the discursive content of speeches and the observation of social interaction, which results in an ethnographic text characterized by a dense description. In relation to the dissertation’s specific goals, we seek to present a general overview of the emergence and development of Therapeutic Communities – encompassing general and local considerations - and pointing out to the dynamics of religious healing systems of these institutions, besides the principles that guide them. In methodological terms, I conducted the partial mapping of therapeutic communities located in Rio Grande do Norte state; interviews with Therapeutic Communities coordinators, visits, participant observation in one of these institutions as well as some interviews with crack users and people close to these social agents in relation to the Therapeutic Communities and the treatment offered by them

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The study aims to analyze the effects of topiramato on the craving of crack users. It is an open crossover clinical trial involving users from the Psychosocial Care Center for Alcohol and Drugs (CAPSad) in city of Parnamirim, RN, approved by the CEP CAAE: 38710614.1.0000.5537, respecting the norms of the resolution n. 466/2012/CNS. The study produced preliminary two scientific papers: a theoretical essay and an integrative review, as a way of seeking the state of art. The first paper was based in the theoretical framework of Hinds, Chaves and Cypress, which focuses different contexts, from the issues of individual use to the coping policies in Brazil, highlighting that the situation and the complexity of the phenome requires coping strategies for the full attention to the user, family and society. As a result of the integrative review, among the 902 retrieved records, eight of them presented therapeutic schemes with positive effects for the craving of cocaine. They used nine different drugs. It is important to spot out that there was no result for the craving of crack. The data collection was conducted from December 2014 to July 2015 and has as sample predominantly single males. The sample was composed of 30 subjects who met the inclusion criteria: adults, age from 18 years, diagnosis of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) for cocaine/crack; cognitive capacity preserved; attendance to the service, participated at least three visits in the 12 months prior to data collection; and accepted to be monitored in the proposed treatment. Data was analyzed using descriptive statistics from the Statistical Package of Support for Social Sciences (SPSS) on the instruments: 1) Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST), pointing out, among other results, that only 14% used crack/cocaine weekly during treatment, while 83% used daily or weekly after the washout period; 2) Barratt Impulsiveness Scale, with an average of 80.23 and 77.47 with and without drug treatment, respectively. An analysis from the Student t test show no significant differences in impulsivity with or without the drug; and 3) Cocaine-Craving Questionnaire-Brief (CCK-B), indicating that the number of users with craving intensity level is significantly higher without drug treatment (86%) than with treatment (33%). The analysis between craving and level of impulsivity showed that there is a low correlation (Pearson) between these two variables during treatment and after the washout, demonstrating that impulsivity has low influence on the outcome of drug therapy. As conclusion, it was noted that the topiramate produces positive effect on reducing the craving for crack users and their use is a relevant strategy for efficacy in the treatment of crack users.

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The study aims to analyze the effects of topiramato on the craving of crack users. It is an open crossover clinical trial involving users from the Psychosocial Care Center for Alcohol and Drugs (CAPSad) in city of Parnamirim, RN, approved by the CEP CAAE: 38710614.1.0000.5537, respecting the norms of the resolution n. 466/2012/CNS. The study produced preliminary two scientific papers: a theoretical essay and an integrative review, as a way of seeking the state of art. The first paper was based in the theoretical framework of Hinds, Chaves and Cypress, which focuses different contexts, from the issues of individual use to the coping policies in Brazil, highlighting that the situation and the complexity of the phenome requires coping strategies for the full attention to the user, family and society. As a result of the integrative review, among the 902 retrieved records, eight of them presented therapeutic schemes with positive effects for the craving of cocaine. They used nine different drugs. It is important to spot out that there was no result for the craving of crack. The data collection was conducted from December 2014 to July 2015 and has as sample predominantly single males. The sample was composed of 30 subjects who met the inclusion criteria: adults, age from 18 years, diagnosis of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) for cocaine/crack; cognitive capacity preserved; attendance to the service, participated at least three visits in the 12 months prior to data collection; and accepted to be monitored in the proposed treatment. Data was analyzed using descriptive statistics from the Statistical Package of Support for Social Sciences (SPSS) on the instruments: 1) Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST), pointing out, among other results, that only 14% used crack/cocaine weekly during treatment, while 83% used daily or weekly after the washout period; 2) Barratt Impulsiveness Scale, with an average of 80.23 and 77.47 with and without drug treatment, respectively. An analysis from the Student t test show no significant differences in impulsivity with or without the drug; and 3) Cocaine-Craving Questionnaire-Brief (CCK-B), indicating that the number of users with craving intensity level is significantly higher without drug treatment (86%) than with treatment (33%). The analysis between craving and level of impulsivity showed that there is a low correlation (Pearson) between these two variables during treatment and after the washout, demonstrating that impulsivity has low influence on the outcome of drug therapy. As conclusion, it was noted that the topiramate produces positive effect on reducing the craving for crack users and their use is a relevant strategy for efficacy in the treatment of crack users.

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Disparities in the crack/cocaine discourse have changed drastically since its inception over 30 years ago. Since the late 1980s, research examining this particular abuse has become more complex as both nationally and globally crack use/abuse has been examined within various contexts. Crack use has often been framed as an African American problem in part resulting from the high volume of African Americans seeking treatment for illnesses associated with their crack-cocaine use, and more African Americans dying from crack-cocaine overdose. This logical fallacy persists despite evidence showing African Americans have lower substance use/abuse compared to Caucasians. Given the impact of the crack epidemic as well as its related drug policies on African American communities and their families, further examination of crack use/abuse is necessary. This study will discuss the crack epidemic historically and examine crack use among clients of a large sample of outpatient substance abuse treatment units over a decade period between 1995 and 2005.

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Thermal and fatigue cracking are the two of the major pavement distress phenomena that contribute significantly towards increased premature pavement failures in Ontario. This in turn puts a massive burden on the provincial budgets as the government spends huge sums of money on the repair and rehabilitation of roads every year. Governments therefore need to rethink and re-evaluate their current measures in order to prevent it in future. The main objectives of this study include: the investigation of fatigue distress of 11 contract samples at 10oC, 15oC, 20oC and 25oC and the use of crack-tip-opening-displacement (CTOD) requirements at temperatures other than 15oC; investigation of thermal and fatigue distress of the comparative analysis of 8 Ministry of Transportation (MTO) recovered and straight asphalt samples through double-edge-notched-tension test (DENT) and extended bending beam rheometry (EBBR); chemical testing of all samples though X-ray Fluorescence (XRF) and Fourier transform infrared analysis (FTIR); Dynamic Shear Rheometer (DSR) higher and intermediate temperature grading; and the case study of a local Kingston road. Majority of 11 contract samples showed satisfactory performance at all temperatures except one sample. Study of CTOD at various temperatures found a strong correlation between the two variables. All recovered samples showed poor performance in terms of their ability to resist thermal and fatigue distress relative to their corresponding straight asphalt as evident in DENT test and EBBR results. XRF and FTIR testing of all samples showed the addition of waste engine oil (WEO) to be the root cause of pavement failures. DSR high temperature grading showed superior performance of recovered binders relative to straight asphalt. The local Kingston road showed extensive signs of damage due to thermal and fatigue distress as evident from DENT test, EBBR results and pictures taken in the field. In the light of these facts, the use of waste engine oil and recycled asphalt in pavements should be avoided as these have been shown to cause premature failure in pavements. The DENT test existing CTOD requirements should be implemented at other temperatures in order to prevent the occurrences of premature pavement failures in future.

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An investigation was carried out on CLT panels made from Sitka spruce in order to establish the effect of the thickness of CLT panels on the bending stiffness and strength and the rolling shear. Bending and shear tests on 3-layer and 5-layer panels were performed with loading in the out-of-plane and in-plane directions. ‘Global’ stiffness measurements were found to correlate well with theoretical values. Based on the results, there was a general tendency that both the bending strength and rolling shear decreased with panel thickness. Mean values for rolling shear ranged from 1.0 N/mm2 to 2.0 N/mm2 .

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A new variant of the Element-Free Galerkin (EFG) method, that combines the diffraction method, to characterize the crack tip solution, and the Heaviside enrichment function for representing discontinuity due to a crack, has been used to model crack propagation through non-homogenous materials. In the case of interface crack propagation, the kink angle is predicted by applying the maximum tangential principal stress (MTPS) criterion in conjunction with consideration of the energy release rate (ERR). The MTPS criterion is applied to the crack tip stress field described by both the stress intensity factor (SIF) and the T-stress, which are extracted using the interaction integral method. The proposed EFG method has been developed and applied for 2D case studies involving a crack in an orthotropic material, crack along an interface and a crack terminating at a bi-material interface, under mechanical or thermal loading; this is done to demonstrate the advantages and efficiency of the proposed methodology. The computed SIFs, T-stress and the predicted interface crack kink angles are compared with existing results in the literature and are found to be in good agreement. An example of crack growth through a particle-reinforced composite materials, which may involve crack meandering around the particle, is reported.

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Several problems arise when measuring the mode II interlaminar fracture toughness using a Transverse Crack Tension specimen; in particular, the fracture toughness depends on the geometry of the specimen and cannot be considered a material parameter. A preliminary experimental campaign was conducted on TCTs of different sizes but no fracture toughness was measured because the TCTs failed in an unacceptable way, invalidating the tests. A comprehensive numerical and experimental investigation is conducted to identify the main causes of this behaviour and a modification of the geometry of the specimen is proposed. It is believed that the obtained results represent a significant contribution in the understanding of the TCT test as a mode II characterization procedure and, at the same time, provide new guidelines to characterize the mode II crack propagation under tensile loads.

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Cette thèse s’inscrit dans le contexte d’une optimisation industrielle et économique des éléments de structure en BFUP permettant d’en garantir la ductilité au niveau structural, tout en ajustant la quantité de fibres et en optimisant le mode de fabrication. Le modèle développé décrit explicitement la participation du renfort fibré en traction au niveau local, en enchaînant une phase de comportement écrouissante suivie d’une phase adoucissante. La loi de comportement est fonction de la densité, de l’orientation des fibres vis-à-vis des directions principales de traction, de leur élancement et d’autres paramètres matériaux usuels liés aux fibres, à la matrice cimentaire et à leur interaction. L’orientation des fibres est prise en compte à partir d’une loi de probabilité normale à une ou deux variables permettant de reproduire n’importe quelle orientation obtenue à partir d’un calcul représentatif de la mise en oeuvre du BFUP frais ou renseignée par analyse expérimentale sur prototype. Enfin, le modèle reproduit la fissuration des BFUP sur le principe des modèles de fissures diffuses et tournantes. La loi de comportement est intégrée au sein d’un logiciel de calcul de structure par éléments finis, permettant de l’utiliser comme un outil prédictif de la fiabilité et de la ductilité globale d’éléments en BFUP. Deux campagnes expérimentales ont été effectuées, une à l’Université Laval de Québec et l’autre à l’Ifsttar, Marne-la-Vallée. La première permet de valider la capacité du modèle reproduire le comportement global sous des sollicitations typiques de traction et de flexion dans des éléments structurels simples pour lesquels l’orientation préférentielle des fibres a été renseignée par tomographie. La seconde campagne expérimentale démontre les capacités du modèle dans une démarche d’optimisation, pour la fabrication de plaques nervurées relativement complexes et présentant un intérêt industriel potentiel pour lesquels différentes modalités de fabrication et des BFUP plus ou moins fibrés ont été envisagés. Le contrôle de la répartition et de l’orientation des fibres a été réalisé à partir d’essais mécaniques sur prélèvements. Les prévisions du modèle ont été confrontées au comportement structurel global et à la ductilité mis en évidence expérimentalement. Le modèle a ainsi pu être qualifié vis-à-vis des méthodes analytiques usuelles de l’ingénierie, en prenant en compte la variabilité statistique. Des pistes d’amélioration et de complément de développement ont été identifiées.

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A significant part of the life of a mechanical component occurs, the crack propagation stage in fatigue. Currently, it is had several mathematical models to describe the crack growth behavior. These models are classified into two categories in terms of stress range amplitude: constant and variable. In general, these propagation models are formulated as an initial value problem, and from this, the evolution curve of the crack is obtained by applying a numerical method. This dissertation presented the application of the methodology "Fast Bounds Crack" for the establishment of upper and lower bounds functions for model evolution of crack size. The performance of this methodology was evaluated by the relative deviation and computational times, in relation to approximate numerical solutions obtained by the Runge-Kutta method of 4th explicit order (RK4). Has been reached a maximum relative deviation of 5.92% and the computational time was, for examples solved, 130,000 times more higher than achieved by the method RK4. Was performed yet an Engineering application in order to obtain an approximate numerical solution, from the arithmetic mean of the upper and lower bounds obtained in the methodology applied in this work, when you don’t know the law of evolution. The maximum relative error found in this application was 2.08% which proves the efficiency of the methodology "Fast Bounds Crack".

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Thin film adhesion often determines microelectronic device reliability and it is therefore essential to have experimental techniques that accurately and efficiently characterize it. Laser-induced delamination is a novel technique that uses laser-generated stress waves to load thin films at high strain rates and extract the fracture toughness of the film/substrate interface. The effectiveness of the technique in measuring the interface properties of metallic films has been documented in previous studies. The objective of the current effort is to model the effect of residual stresses on the dynamic delamination of thin films. Residual stresses can be high enough to affect the crack advance and the mode mixity of the delimitation event, and must therefore be adequately modeled to make accurate and repeatable predictions of fracture toughness. The equivalent axial force and bending moment generated by the residual stresses are included in a dynamic, nonlinear finite element model of the delaminating film, and the impact of residual stresses on the final extent of the interfacial crack, the relative contribution of shear failure, and the deformed shape of the delaminated film is studied in detail. Another objective of the study is to develop techniques to address issues related to the testing of polymeric films. These type of films adhere well to silicon and the resulting crack advance is often much smaller than for metallic films, making the extraction of the interface fracture toughness more difficult. The use of an inertial layer which enhances the amount of kinetic energy trapped in the film and thus the crack advance is examined. It is determined that the inertial layer does improve the crack advance, although in a relatively limited fashion. The high interface toughness of polymer films often causes the film to fail cohesively when the crack front leaves the weakly bonded region and enters the strong interface. The use of a tapered pre-crack region that provides a more gradual transition to the strong interface is examined. The tapered triangular pre-crack geometry is found to be effective in reducing the stresses induced thereby making it an attractive option. We conclude by studying the impact of modifying the pre-crack geometry to enable the testing of multiple polymer films.