717 resultados para Contact transformations.


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Cover title.

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A robot’s drive has to exert appropriate driving forces that can keep its arm and end effector at the proper position, velocity and acceleration, and simultaneously has to compensate for the effects of the contact forces arising between the tool and the workpiece depending on the needs of the actual technological operation. Balancing the effects of a priori unknown external disturbance forces and the inaccuracies of the available dynamic model of the robot is also important. Technological tasks requiring well prescribed end effector trajectories and contact forces simultaneously are challenging control problems that can be tackled in various manners.

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Durant le dernier demi-siècle, la religion, comme tous les autres domaines d’activité humaine, a connu plusieurs transformations importantes. La diminution considérable, durant cette période, de la pratique religieuse institutionnalisée est accompagnée de l’apparition d’une multitude de nouvelles formes de spiritualités qui tentent de répondre aux besoins religieux de l’homme occidental. Parmi les multiples manifestations de ce genre, on découvre une spiritualité distincte, appelée néo-chamanisme ou chamanisme urbain, réunissant de nombreuses pratiques contemporaines qui se définissent comme chamaniques. Dans le cadre de ce mémoire, nous nous sommes concentrés sur l’étude du phénomène néo-chamanique de Michael Harner, ex-professeur et directeur du département d’anthropologie au Graduate Faculty of the New School for Social Research à New York, et fondateur de la Foundation for Shamanic Studies (à l’avenir : FSS). La présente recherche a pour but d’analyser le néo-chamanisme de Harner et de définir sa place parmi les nouvelles formes de religiosités. La théorie de la recomposition du religieux de Danièle Hervieu-Léger sert de cadre d’analyse pour cette nouvelle forme de spiritualité. Dans la première partie, nous traitons le phénomène religieux contemporain sous l’angle socioreligieux. Nous présentons un aperçu global des transformations que celui-ci subit en modernité sous l’impact de la sécularisation. À l’aide de la théorie des nouvelles formes religieuses de Danièle Hervieu-Léger, nous mettons en lumière les principales règles selon lesquelles une nouvelle configuration du religieux se déploie dans le contexte occidental contemporain. Dans la seconde partie, nous examinons le chamanisme traditionnel sous l’angle anthropologique. Nous faisons la lecture d’études classiques sur le chamanisme. Il apparaît que le chamanisme classique est communautaire, réservé à quelques personnes choisies par les esprits et que le processus laborieux d’initiation permettant d’accéder à cette fonction implique certains éléments spécifiques parmi lesquels on compte la maladie initiatique, la mort rituelle et la résurrection de la personne. Dans la troisième partie, nous examinons le néo-chamanisme de Harner. Nous rendons compte de son ouvrage majeur La voie spirituelle du chamane : Le Secret d'un sorcier indien d’Amérique du Nord et nous examinons l’expérience chamanique de la Foundation for Shamanic Studies (FSS). Il se dégage de cette étude que l’approche de Harner se veut l’expression d’un chamanisme fondamental et universel adapté à la société contemporaine. La pratique néo-chamanique de Harner se focalise sur le voyage chamanique et sur le contact avec le monde des esprits comme des éléments qui sont au cœur du chamanisme traditionnel. C’est une pratique axée principalement sur l’individu à des fins d’accomplissement de soi et d’(auto)guérison. Elle attire généralement des personnes dont le niveau de scolarité est élevé, disposées à payer pour les services fournis par la fondation. À la fin de notre étude, nous dégageons les conclusions générales suivantes : le néo-chamanisme de Harner s’éloigne de la tradition chamanique et la transforme en une spiritualité nouvelle adaptée aux besoins des Occidentaux; il reflète les transformations subies par le fait religieux pendant la période moderne; il s’adresse principalement à un public en quête de services spirituels ciblés et ponctuels et il favorise une forme de communalisation temporaire et intense; cependant, l’individuation de la pratique chamanique est porteuse de ses effets politiques et néocoloniaux.

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The research which underpins this paper began as a doctoral project exploring archaic beliefs concerning Otherworlds and Thin Places in two particular landscapes - the West Coast of Wales and the West Coast of Ireland. A Thin Place is an ancient Celtic Christian term used to describe a marginal, liminal realm, beyond everyday human experience and perception, where mortals could pass into the Otherworld more readily, or make contact with those in the Otherworld more willingly. To encounter a Thin Place in ancient folklore was significant because it engendered a state of alertness, an awakening to what the theologian John O’ Donohue (2004: 49) called “the primal affection.” These complex notions and terms will be further explored in this paper in relation to Education. Thin Teaching is a pedagogical approach which offers students the space to ruminate on the possibility that their existence can be more and can mean more than the categories they believed they belonged to or felt they should inhabit. Central to the argument then, is that certain places and their inhabitants can become revitalised by sensitively considered teaching methodologies. This raises interesting questions about the role spirituality plays in teaching practice as a tool for healing in the twenty first century.

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Composite resins might be susceptible to degradation and staining when in contact with some foods and drinks. This study evaluated color alteration and changes in microhardness of a microhybrid composite after immersion in different colored foods and determined whether there was a correlation between these two variables. Eighty composite disks were randomly divided into 8 experimental groups (n = 10): kept dry; deionized water; orange juice; passion fruit juice; grape juice; ketchup; mustard and soy sauce. The disks were individually immersed in their respective test substance at 37 ºC, for a period of 28 days. Superficial analysis of the disk specimens was performed by taking microhardness measurements (Vickers, 50 g load for 45 seconds) and color alterations were determined with a spectrophotometer (CINTRA 10- using a CIEL*a*b* system, 400-700 nm wavelength, illuminant d65 and standard observer of 2º) at the following times: baseline (before immersion), 1, 7, 14, 21 and 28 days. Results were analyzed by ANOVA and Tukey's test (p < 0.05). Both variables were also submitted to Pearson's correlation test (p < 0.05). The passion fruit group underwent the greatest microhardness change, while the mustard group suffered the greatest color alteration. Significant positive correlation was found between the two variables for the groups deionized water, grape juice, soy sauce and ketchup. Not all color alteration could be associated with surface degradation.

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We study how the crossover exponent, phi, between the directed percolation (DP) and compact directed percolation (CDP) behaves as a function of the diffusion rate in a model that generalizes the contact process. Our conclusions are based in results pointed by perturbative series expansions and numerical simulations, and are consistent with a value phi = 2 for finite diffusion rates and phi = 1 in the limit of infinite diffusion rate.

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Aim of this study was to analyse contact endoscopy as an auxiliary method for identifying parathyroid glands during thyroid surgery and to identify other variables that may interfere with this correlation. overall, 125 patients underwent thyroid surgery between January 2004 and February 2006. The variables analysed were: the total duration of surgery; time taken to locate and identify parathyroid glands; improvement in identifying these; numbers of parathyroid glands located by the surgeon and confirmed by contact endoscopy; histopathological diagnosis; presence of thyroiditis; thyroid weight; number of parathyroid glands left in thyroid specimens; and number of parathyroid gland autotransplantations. A total of 331 parathyroid glands were observed by the surgeon. however, 282 glands were identified by contact endoscopy. nine parathyroid glands (7.2%) were observed together with thyroid specimens (Kappa = 0.534). The longer the total duration of surgery (p = 0.03) and time taken to locate and identify (p = 0.00) the parathyroid glands by contact endoscopy, the lower the observed agreement. The second year of performing contact endoscopy led to better agreement between the results (p = 0.02). in conclusion, contact endoscopy is an efficient auxiliary method for identifying parathyroid glands during thyroid surgery. During the period studied, association between total duration of surgery and time taken to locate and identify parathyroid glands was statistically significant.

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Background Tuberculosis clusters in families may be due to increased household exposure, shared genetic factors, or both. Household contact studies are useful to control exposure because socioeconomic and environmental conditions are similar to all subjects, allowing the evaluation of the contribution of relatedness to disease development. Methods In this study, the familial aggregation of tuberculosis using relatedness and a specific inherited marker (HLA-DRB1) was evaluated. Fifty families, which had at least two cases of tuberculosis diagnosed within the past 5 years, were selected from a cohort of tuberculosis carried out in Recife, Brazil. The first case diagnosed was considered to be a primary case. The secondary attack rate of tuberculosis in household contacts was estimated according to the degree of relatedness. The relative risk of having tuberculosis based on the degree of relatedness household and the population attributable fraction to relatedness were also estimated. HLA-DRB1 typing and attributable etiologic/preventive fractions were calculated among sick and healthy household contacts. Results Compared to unrelated contacts, the relative risk for tuberculosis adjusted for age was 1.38 (95% CI 0.86 to 2.21). Relatedness contributed 23% to the development of tuberculosis at the population levels. The HLA-DRB1*04 allele group (OR = 2.44; p =0.0324; etiologic fraction =0.15) was overrepresented and the DRB1*15 allele group (OR=0.48; p=0.0488; protective fraction=0.19) was underrepresented among household contacts exhibiting tuberculosis. The presence of DRB1 shared alleles between primary cases and their contacts was a risk factor for tuberculosis (p=0.0281). Conclusion This household contact model together with the utilisation of two genetic variables permitted the evaluation of genetic factors contributing towards tuberculosis development.

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There exist uniquely ergodic affine interval exchange transformations of [0,1] with flips which have wandering intervals and are such that the support of the invariant measure is a Cantor set.

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Objectives: to identify women`s feelings after early contact with their newborn infants in the delivery room, and to identify how health professionals involved in mother and infant care behave in the intrapartum setting. Design: a qualitative approach using semi-structured interviews and observation. Content analysis was used to derive the three themes that emerged from the interviews. Setting and participants: 23 postpartum women and their caregivers in a public maternity hospital in Ribeirao Preto, Brazil. Findings: three thematic categories emerged from the interviews: heightened fear, severe pain and intense conflict. The professionals` actions revealed that they have theoretical and practical abilities for humanisation of care, but their actions are fragmented. Final considerations: women can feel lonely, fearful and conflicted in the delivery room, and they also experience pain. Giving birth is a major event in a woman`s life, so it is important to facilitate a positive experience. Health professionals were found to display interventionist and impersonal attitudes; these influenced the potential choices of women at their first contact with their infant. Implications for practice: the focus of health care needs to extend beyond the institution. This means fewer normative actions performed by health professionals, enabling women to enjoy their early contact with their newborn infants. (C) 2010 Elsevier Ltd. All rights reserved.

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Background and purpose: Several promising non-pharmacological interventions have been developed to reduce acute pain in preterm infants including skin-to-skin contact between a mother and her infant. However, variability in physiological outcomes of existing studies on skin-to-skin makes it difficult to determine treatment effects of this naturalistic approach for the preterm infant. The aim of this study was to test the efficacy of mother and infant skin-to-skin contact during heel prick in premature infants. Method: Fifty nine stable preterm infants (born at least 30 weeks gestational age) who were undergoing routine heel lance were randomly assigned to either 15 min of skin-to-skin contact before, during and following heel prick (n = 31, treatment group), or to regular care (n = 28, control group). Throughout the heel lance procedure, all infants were assessed for change in facial action (NFCS), behavioral state, crying, and heart rate. Results: Statistically significant differences were noted between the treatment and control groups during the puncture, heel squeeze and the post phases of heel prick. Infants who received skin-to-skin contact were more likely to show lower NFCS scores throughout the procedure. Both groups of infants cried and showed increased heart rate during puncture and heel squeeze although changes in these measures were less for the treated infants. Conclusions: Skin-to-skin contact promoted reduction in behavioral measures and less physiological increase during procedure. It is recommended that skin-to-skin contact be used as a non-pharmacologic intervention to relieve acute pain in stable premature infants born 30 weeks gestational age or older. (C) 2007 European Federation of Chapters of the International Association for the Study of Pain. Published by Elsevier Ltd. All rights reserved.

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This work presents a non-linear boundary element formulation applied to analysis of contact problems. The boundary element method (BEM) is known as a robust and accurate numerical technique to handle this type of problem, because the contact among the solids occurs along their boundaries. The proposed non-linear formulation is based on the use of singular or hyper-singular integral equations by BEM, for multi-region contact. When the contact occurs between crack surfaces, the formulation adopted is the dual version of BEM, in which singular and hyper-singular integral equations are defined along the opposite sides of the contact boundaries. The structural non-linear behaviour on the contact is considered using Coulomb`s friction law. The non-linear formulation is based on the tangent operator in which one uses the derivate of the set of algebraic equations to construct the corrections for the non-linear process. This implicit formulation has shown accurate as the classical approach, however, it is faster to compute the solution. Examples of simple and multi-region contact problems are shown to illustrate the applicability of the proposed scheme. (C) 2011 Elsevier Ltd. All rights reserved.

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This paper aims to investigate the influence of some dissolved air flotation (DAF) process variables (specifically: the hydraulic detention time in the contact zone and the supplied dissolved air concentration) and the pH values, as pretreatment chemical variables, on the micro-bubble size distribution (BSD) in a DAF contact zone. This work was carried out in a pilot plant where bubbles were measured by an appropriate non-intrusive image acquisition system. The results show that the obtained diameter ranges were in agreement with values reported in the literature (10-100mm), quite independently of the investigated conditions. The linear average diameter varied from 20 to 30mm, or equivalently, the Sauter (d(3,2)) diameter varied from 40 to 50mm. In all investigated conditions, D(50) was between 75% and 95%. The BSD might present different profile (with a bimodal curve trend), however, when analyzing the volumetric frequency distribution (in some cases with the appearance of peaks in diameters ranging from 90-100mm). Regarding volumetric frequency analysis, all the investigated parameters can modify the BSD in DAF contact zone after the release point, thus potentially causing changes in DAF kinetics. This finding prompts further research in order to verify the effect of these BSD changes on solid particle removal efficiency by DAF.

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The present work reports on the effect of the type of backside contact used in the electrochemical process and their relation with the structural features and optical responses of the one-dimensional photonic crystal (PC) anodized in simple and double electrochemical cell. The PC, obtained in the single cell, showed to have thicker layers than of the PC obtained in double electrochemical cell. Additionally, the PC obtained in double cell showed highest reflectance in the band gap region than of the PCs obtained in single cell. These results suggest that the interface roughness between adjacent layers in the PC devices obtained in double electrochemical cell is minimized. (C) 2008 Elsevier Ltd. All rights reserved.

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There are several ways of controlling the propagation of a contagious disease. For instance, to reduce the spreading of an airborne infection, individuals can be encouraged to remain in their homes and/or to wear face masks outside their domiciles. However, when a limited amount of masks is available, who should use them: the susceptible subjects, the infective persons or both populations? Here we employ susceptible-infective-recovered (SIR) models described in terms of ordinary differential equations and probabilistic cellular automata in order to investigate how the deletion of links in the random complex network representing the social contacts among individuals affects the dynamics of a contagious disease. The inspiration for this study comes from recent discussions about the impact of measures usually recommended by health public organizations for preventing the propagation of the swine influenza A (H1N1) virus. Our answer to this question can be valid for other eco-epidemiological systems. (C) 2010 Elsevier BM. All rights reserved.