941 resultados para ondas ultrassônicas


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

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O presente trabalho apresenta equações de estimativa da radiação fotossinteticamente ativa global () e difusa () em função das respectivas radiações global () e difusa () do espectro solar total, bem como a estimativa da fração PAR difusa da PAR global () em função do índice de transmissividade atmosférica (). A base de dados foi adquirida no período de 01/06/1999 a 31/09/2000 na Estação de Radiometria Solar da FCA-UNESP, Botucatu. Foram utilizados dados adicionais, diferentes dos utilizados na geração dos modelos, de forma a possibilitar uma validação adequada dos modelos propostos.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Engenharia Elétrica - FEIS

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Pós-graduação em Engenharia Elétrica - FEIS

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Pós-graduação em Engenharia Mecânica - FEIS

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

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Atmospheric Discharges are responsible for several lost in the electrical system therefore it´s done studies to find ways to reduce the problem caused by discharges. This branch of engineering is necessary the gathering, stock and analysis of large quantity of data to validate or refuse the many studies produced about it The CENDAT proposed a project to collect data on induced voltages in distribution lines and current waveform of the lightning, but a difficulty that arose was the accumulation of data due to lack of manpower available to catalog all the data collected. Thinking in this difficulty, the engineer Acacio Silva Neto CENDAT´s researcher with trainees began to develop a program to solve this problem. This work keeps the development of this program in order to solve the problem of accumulation of data

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Pipelines are linear engineering works, designed mostly for transporting oil and its derivatives for long distances, furnishing even the farthermost zones of the country. Due to oil sector needs to ensure for the safety and conservation of its properties, several geotechnical studies are being held at the pipelines field, in order to preserve this important transportation, and also to prevent accidents, which might seriously compromise the environment and the population who lives around it. The OSBRA pipeline, who connects the city of Paulínia to the capital Brasília, is one of these engineering works that deserves to be pointed out. This research, performed at the Ribeirão da Prata Basin, was a pilot study conducted with the main objective of testing the current methodology efficiency, for future applications in the closest watersheds to the OSBRA pipeline. The objective of this research is to analyze flood wave and debris flow processes in a non-fictional watershed, by comparing two different kinds of methods: the first one based on simulation models (software ‘ABC 6’), and the other one by flood wave and debris flow susceptibility mapping. The results from the hydrological modeling were both hydrographs and ietographs that estimated values of outputs and infiltration. To construct the susceptibility maps were necessary three other maps: ground use and occupation maps, divided according to the different protection degrees that were offered to the ground; maps of dam locations in the area and physiographic compartimentation maps, divided according to the local geology. To complete the methodology, the results were collected from both methods for comparison. The obtained product for this methodology was series of data whose different susceptibility degrees to flood wave and debris flow could define the safest route for a pipeline crossing in this watershed...

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Given the intense expansion of the industries in Brazil and the discovery of hydrocarbons in the pre-salt layer of the Santos and Campos Basin, there is a need to expand the distribution of oil and gas network in the country. The present work aims to present the development of susceptibility map by two distinct methods of two events (debris flows and full wave), applied to the establishment of pipelines on Ribeirão da Prata Basin. The research area covers two municipalities: São João da Boa Vista and Águas da Prata, in total 145 km2. In the paper was used the methodology proposed by Zaine (2011) for the physiographic subdivision method, which uses geological maps, geomorphological maps, digital terrain models and aerial photographs, used to extract the main elements of the physical environment, as rivers, lines, ridges, tops forms and valley forms and historical processes. Thus, the basin was divided into 11 physiographic zones, considering the following elements: thickness of soil, rock type, geomorphology, amplitude, ridges orientation, erosion occurences and mass movements. Were subsequently performed location maps of dams, that had as main purpose to localize major dams in the study area along with their area and perimeter of the reservoir, and land use map that subdivided the area in woody vegetation, permanent culture, temporary culture and urban area. Along with the preparation of the auxiliar maps was conducted a field campaign with three days and approximately 2 points per km2, which aimed to better understand the physical environment and check the main peculiarities of the study area. Criteria have been established for susceptibility maps physiographic subdivision and land use, and a survey of criteria weights used in each map for both processes under study. For the preparation of susceptibility maps were adopted two different methods, which treat the weighted average and the multiplicand. The weighted average method it is...

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Pós-graduação em Engenharia Mecânica - FEIS

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The application of ultrasonic waves during the initial setting of the glass ionomer cements (GIC) has demonstrated increase of the cure speed, reduction of air bubbles and improves in some mechanical properties. The aim of this study was to evaluate the effect of the ultrasound on the microhardness and the superficial roughness in two GICs (FUJI IX GP (GC Corporation) and Ketac Molar EasyMix (3M ESPE)). Forty specimens were confectioned, twenty for evaluation of the superficial roughness and twenty for evaluation of the microhardness. Half of them received for thirty seconds the ultrasonic waves application. The readings of the roughness had been carried before and after the toothbrushing test. The twenty remaining specimens had been polished with abrasive sandpapers of decreasing granulations and submitted to the hardness test. The results, analyzed for the variance analysis (ANOVA) (p<0,05), had demonstrated increase of the hardness for all the groups with the application of ultrasonic waves, being bigger for the Ketac Molar EasyMix. The ultrasound application also caused significant reduction of the superficial roughness for the Ketac Molar EasyMix. After the toothbrushing test, this last property increased for all the materials. It could be concluded that the application of ultrasonic waves was effective in increasing the superficial hardness of the materials and that it improved the roughness of the Ketac Molar EasyMix before the toothbrushing test.