1000 resultados para Perigos físicos não metálicos


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Hazard analysis and critical control points (HACCP) is one of the main tools currently used to ensure safety, quality and integrity of foods. So, the aim of this study was to develop and implement the HACCP program in the processing of pasteurized grade A milk Checklists were used to assess on the level of the pre requisites programs and on the sanitary classification of the dairy industry and the results were used as references for the development of the HACCP system. A "decision tree" protocol was used for the identification of the critical control points (CCP). No physical or chemical CCP were identified, whereas pasteurization and packaging were considered biological CCP For these CCP, the limits for prevention, monitoring needs, corrective actions, critical limits and verification procedures were established. The pre requisites program was essential for the establishment of the system. The implementation of the HACCP for the processing of grade A pasteurized milk was efficient to control the biological hazards and enabled the product to comply with the legislation specifications and achieve safety.

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Pós-graduação em Odontologia Restauradora - ICT

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A avaliação dos atributos químicos e físicos do solo é necessária em estudos que exploram intensivamente os sistemas de pastejo. No presente trabalho, objetivou-se avaliar as variações nos atributos físicos e químicos de um Argissolo cultivado com capim-milênio, sob pastejo, no intervalo compreendido entre outubro/2001 e maio/2002, no quinto ano de aplicação sucessiva das seguintes doses de N: 0, 150, 300 e 450 kg ha-1. Após os cinco anos de aplicação de 450 kg ha-1 de N, o teor de MO aumentou em 5 g dm-3, o que resultou em aumento da CTC. No período de outubro/2001 a maio/2002 houve diminuição nos valores de pH e de V com a aplicação de N. A densidade do solo variou pouco com a adubação nitrogenada; a percentagem de microporos aumentou e a de macroporos diminuiu na camada de 0-5 cm com o aumento das doses de N, mas a porosidade total permaneceu constante; e a resistência à penetração, quando o solo apresentava 90 g kg-1 de água, não foi afetada pelas doses de N e não foi restritiva ao crescimento das plantas.

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Using the sol-gel process, organic-inorganic hybrid coatings were synthesized by incorporation of different concentrations of functionalized carbon nanotubes, to improve their mechanical strength and thermal resistance without changing its passivation character. The siloxane-PMMA hybrids were prepared by radical polymerization of methyl methacrylate (MMA) with 3-methacryloxipropiltrimethoxisilane (MPTS) using the thermal initiator benzoyl peroxide (BPO), followed by acid catalyzed hydrolysis and condensation of tetraethoxysilane (TEOS). The analysis of pristine and functionalized carbon nanotubes was carried out using Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy and Raman Spectroscopy. Structural analysis of hybrids was performed by Nuclear Magnetic Resonance, Atomic Force Microscopy and Raman Spectroscopy. For analysis of mechanical strength and thermal stability were performed mechanical compression tests and thermogravimetric analysis, respectively. Electrochemical Impedance Spectroscopy was used to evaluate the corrosion resistance in saline environment. The results showed an effective functionalization of carbon nanotubes with carboxyl groups and conservation of its structure. The hybrids showed high siloxane network connectivity and roughness of approximately 0.3 nm. The incorporation of carbon nanotubes in the hybrid matrix did not change significantly their thermal stability. Samples containing carbon nanotubes exhibit good corrosion resistance (on the order of MΩ in saline environment), but the lack of complete dispersion of carbon nanotubes in the hybrid, resulted in a loss of mechanical and corrosion resistance compared to hybrid matrix.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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In this paper, we analyze the educational importance of teaching Physics in the early grades of elementary school from a teaching experience with students of 5th grade, using five experiments on electricity and magnetism. The theoretical framework used was the socio-historical psychology, especially Vigotski's studies on concept formation. It can be stated that the teaching of Physics and the use of experimental activities in the early grades cannot be simply associated to the teaching of certain scientific concepts, but should be explored bearing in mind the child's development.

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According to Statistical Yearbook of Social Security (2011), the number of accidents at work recorded in the agricultural sector is quite high, in the year 2010 there are records of thirty-four thousand nine hundred and ninetysix accidents, and in the year of 2011 there were thirty-one thousand and ninety-six accidents in the industry. Among so many diseases and accidents at work hearing loss is one of them. According to the Pan American Health Organization (2011) the Occupational hearing loss is then jury to the worker's health, often in the workplace. Mechanical vibrations are also present in many human activities exposing employees to an extremely aggressive agent. The combined action of these two factors can cause damage to the health of the worker, in this way, noise and vibration are the two major occupational agents present in the brush cutter operator activity. In the case there is another risk factor, the open work, which exposes the employee to the Sun’s rays and the high temperature indices. Studies have shown that: noise exceeds 115 dB (A) vibration 4.0 m/s2 and thermal stress of 29.9 o C. Ergonomic evaluations also demonstrated that the activity cause injury to workers.

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Pós-graduação em Química - IQ

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Modern society is characterized by the advance of technologies, the emergence and constant development of the technological field is responsible for a series of population adjustments, that being practically molded and daily transformed by media, which usually has the power of manipulating opinions and public approaches in every capacity and extensions of our lives, being a significantly and important tool, which most part of individuals in contemporary society can't work and live without, therefore most part of individuals depend on the use of many technological means, including social means, which have great relationship with the development and emergence of many psychological problems that completely impact on the social life of affected individuals, thus Physical Education is an area with the goal of verifying the level of influence that media reflects on the lifestyle choice to be followed and the relation of this influence with the presence and development of a series of psychological disorders that affect directly the health of those individuals. It has been gathered data about the subject according to scientific basis, more specifically, on Academic Google, Scielo and Pubmed, where it has been researched scientific articles that could contribute with the data and information to complete the text. The psychology of sports is an area of studies and knowledge that investigates and develops insight about these questions, making available scientifically tested and proven materials that supports the P.E. professional, that is connected in the practical field to visualize possible chained symptoms of these psychopathologies according to the development of these psychic disorders, that are usually common in current days, more precisely, disorders such as Anorexia, Vigorexia, self-dependence to physical exercise and selfcorporal dissapproval. It's vital to have total attention with the possibility of evolution of this psychopatology...

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Marchantia polymorpha develops under environmental conditions of high relative humidity and shading. As this habitat is the usually used in nurseries for the growth of seedlings of native tree species that species grows very quickly among developing tree seedlings and causes severe losses. This study was undertaken viewing more efficient either physical or chemical methods for the control of M. polymorpha. Two experiments were conducted under greenhouse conditions. In the first acetic acid (10, 20, and 40% of concentration), oxygenated water (50 and 100%) and the herbicides glyphosate (1,680 g AI ha) and fomesafen (375 g AI ha-1 ) were applied to the seedlings. In the second, the treatments consisted of soil previously submitted to a temperature of 105 °C for 48 hours, soil submitted to solarization in black plastic and in transparent plastic bags for 30 days, preemergence application of diuron (1,750 g AI ha-1 ) and trifluralina (1,575 g AI ha-1 ). The visual evaluations of the methods were performed 7, 14, 21, and 28 days after the application (DAA) and at 60 and 120 DAA, respectively, for the first and the second experiment. Only diuron and trifluralina resulted in a 100% control of M. polymorpha 120 DAA.