Construção de um calorímetro isotérmico diferencial de alta sensibilidade e baixo custo

The high cost of sensitivity commercial calorimeters may represent an obstacle for many calorimetric research groups. This work describes the construction and calibration of a batch differential heat conduction calorimeter with sample cells volumes of about 400 μL. The calorimeter was built using two small high sensibility square Peltier thermoelectric sensors and the total cost was estimated to be about US$ 500. The calorimeter was used to study the excess enthalpy of solution of binary mixtures of liquids, as a function of composition, for the following binary systems of solvents: water + 1,4-dioxane or + dimethylsulfoxide at 298,2 ± 0,5 K.

Desenvolvimento e avaliação de uma servoválvula de baixo custo para a aplicação de insumos líquidos

The present work aimed the development of a low cost servo-valve that answers to an electronic control signal, for variable rates liquid inputs application. A literature research to define which valve type should be used was made. A mechanically activated proportional valve with an electronically controlled servo-engine was designed and evaluated. Since developed the servo-valve, the system was submited to a number of tests .The evaluation of its behavior was obtained in terms of repeatability, hystheresis and linearity. The test was accomplished in a bench, specially developed for this aim. As a result, were obtained three curves of opening percentage as function of flow rate, describing three opening and closing increments in two different work pressures. The servo-valve presented a good repeatability, reasonable hysteresis and a typically quadratic curve. This one maintained the low cost target. These results were very satisfied because the non-linearity and the hysteresis could be easily corrected by software.

Óculos de baixo custo: experiência em Divinolândia (SP)

INTRODUCTION: In Divinolândia (SP), the Consortium of Development of São João da Boa Vista Region Policy (CONDERG), in partnership with State University of Campinas (UNICAMP), has founded an eyeglass store to produce low cost glasses to distribute freely to their customers. The purpose is to analyze the evolution and working process of CONDERG eyeglass store in the last 13 years, since its foundation. METHODS: Data were collected from CONDERG store files from 1988 to 2001. Data regarding the amount of spectacles produced per year, ability to increase the production and store feasibility were analyzed. RESULTS: In 13 years, 16,500 spectacles were supplied. Currently, 400 spectacles are delivered per month, being 200 supported by SUS and the other 200 by CONDERG's own resources. CONCLUSION: The 13-year operation of CONDERG eyeglass store, the free provision of 16,500 spectacles and the increase productive ability have shown this model feasibility.

Crescimento, composição corporal e performance motora em crianças e adolescentes de 7 a 14 anos provenientes de familias de baixo nivel socio-economico e participantes do projeto esporte solidario, São Luis - MA

Universidade Estadual de Campinas . Faculdade de Educação Física