Thermodynamic, Dynamic and Structural Anomalies for Shoulder-like potentials

Using molecular dynamic simulations we study a family of continuous core-softened potentials consisting of a hard core, a shoulder at closest distances and an attractive well at further distance. The repulsive shoulder and the well distances represent two length scales. We show that if the first scale, the shoulder, is repulsive or has a small well, the potential has a region in the pressure-temperature phase diagram with density, diffusion and structural anomalies. However, if the closest scale becomes a deep attractive well the regions in the pressure-temperature phase diagram where the three anomalies are present shrink and disappear. This result enables us to predict by the shape of the core-softened potential if anomalies would or would not be present

Investigation of friction hysteresis using a laboratory-scale tribometer

The current paper addresses the characterization of dynamic friction by using a laboratory-scale tribometer. A special post-processing script in MatLab has been developed in order to analyse the data from the experiments. A sine wave signal for the velocity is imposed, with three different frequencies and, consequently, acceleration and deceleration rates. A friction material from brakes, with nominal contact area of 254 mm², was subjected to sliding against a commercially available brake disc (gray cast iron, diameter of 256 mm). Some technical details and adjustments from the designed tribometer are showed and the results from the experiments are discussed. A friction hysteresis has been observed for all experimental curves, which exhibit loops in elliptical shape. A negative slope has been encountered for the curves when the imposed frequency is 1 Hz and 2 Hz, while for the highest frequency (4 Hz) the slope is positive. The laboratory-scale tribometer, associated to the post-processing stage, is capable to successfully be used to characterize friction hysteresis effect

Large deviations for a damped telegraph process

In this paper we consider a slight generalization of the damped telegraph process in Di Crescenzo and Martinucci (2010). We prove a large deviation principle for this process and an asymptotic result for its level crossing probabilities (as the level goes to infinity). Finally we compare our results with the analogous well-known results for the standard telegraph process

Characterization of surface morphology and its correlation with friction performance of brake pads

The present work presents the morphology evolution of a brake material surface submitted to braking tests through a laboratory-scale tribometer. Optical microscope images of the material’s surface were obtained for every 10 braking operations. These images were post-processed in appropriate computational software. By means of the image segmentation technique, morphological parameters related to the brake material surface were estimated. The wear rate and also the coefficient of friction resulting from the tests were measured. For the NAO material used in this study, the friction behaviour revealed to be strongly associated with the amount of contact plateaus. Besides, the mean area of the contact plateaus was the main factor responsible for increasing the real contact area of the friction material. The higher wear rate observed in the first braking operations can be mainly attributed to the higher surface roughness measured in this condition. As the braking operations progress, the plateaus becomes flatter and wear rate is reduced. Finally, the image segmentation technique proved adequate for investigating morphological aspects in friction material surface

Organização de laboratório de microcirurgia

Microsurgical techniques have been used in many surgical specialties as well as a broad application in surgical research.. It demands high technical skills and continued training. The microsurgical skills should be first mastered in the lab before to be employed in the clinical practice. The microsurgical lab has a dual role: the training of residents and specialized surgeons and the support for the high qualified scientific research in experimental surgery. Here, it is presented (showed) the organization of a microsurgical lab, including area and equipments, furthermore there is a proposal that school-hospitals that offer microsurgical procedures, should have a microsurgical laboratory.As técnicas microcirúrgicas têm sido usadas em várias especialidades cirúrgicas, assim como uma ampla aplicação na pesquisa cirúrgica. A realização de microcirurgia exige alta qualidade técnica e treinamento contínuo. O completo domínio das técnicas de microcirurgia deve ser obtido primeiro no laboratório antes de ser empregada na prática clínica. O laboratório de microcirurgia tem uma dupla função: o treinamento de residentes e cirurgiões especialistas e o suporte para a investigação científica em cirurgia experimental. Nesse artigo está apresentado um modelo de laboratório de microcirurgia, incluindo a área e os equipamentos, além da proposta de que os hospitais-escola, que ofereçam procedimentos microcirúrgicos, sejam equipados com laboratório de microcirurgia.Harvard Medical School Brigham and Women's Hospital Division of Transplant SurgeryFederal University of São Paulo Department of SurgeryUNIFESP, Department of SurgerySciEL

D. JORGE MARCOS E A AÇÃO SOCIAL NO ABC PAULISTA

Este estudo objetiva apresentar uma temática que é a relação entre Igreja católica e Estado no Brasil antes e durante o regime militar. Para isso será apresentada a figura do primeiro bispo de Santo André, no ABC paulista, dom Jorge Marcos de Oliveira. Através de suas atividades, tendo sua base no Concílio Vaticano II, será possível visualizar a recepção deste Concílio através de sua ação social. O papel do bispo revela uma preocupação de parte da instituição religiosa na sua reforma interna e na transformação da sociedade brasileira, fincada na justiça social.Enviado: 13-06-2018 - Aprovado e publicado: 11-201

Princípios e práticas fundamentais de uma Igreja cristã saudável = Basic principles and practices of a healthy Christian Church

Este artigo analisa quatro princípios fundamentais encontrados em Atos dos Apóstolos 2,42. Observase que a prática destes princípios contribui para que a igreja cumpra com equilíbrio sua missão e propósito. Os princípios apresentados são: doutrina bíblica, comunhão, partir do pão e oração. Igrejas estagnadas ou em declínio geralmente deixaram de ter estes princípios como centrais em suas práticas. Este artigo demonstra que a prática destes princípios permeia toda historia bíblica e tem sido a marca das reuniões cristãs. Entretanto resgatar a prática destes princípios apenas por imitação tentando transpor para este momento da história seria um anacronismo estéril. Contudo estudá-los como meio de haurir conteúdo e métodos adaptados a este tempo constitui um facilitador para o crescimento da igreja local e para o avanço no trabalho missionário. E por fim é apresentada uma síntese bíblica da importância da prática desses princípios fundamentais para que uma igreja local seja saudáve