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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Medidas e an?lise estat?stica em sinais bioel?tricos sobre pontos de acupuntura

Cruz, Cl?udia Patr?cia Torres 05 October 2007 (has links)
Made available in DSpace on 2014-12-17T15:14:45Z (GMT). No. of bitstreams: 1 ClaudiaPTC.pdf: 3289641 bytes, checksum: e41c19b786c3a7976dfecbc61abd2ca4 (MD5) Previous issue date: 2007-10-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In the 20th century, the acupuncture has spread on occident as a complementary practice of heath care. This fact has motivated the international scientific community to invest in research that seek to understand why acupuncture works. In this work we compare statistically volt age fluctuation of bioelectric signals caught on the skin at an acupuncture point (IG 4) another nearby on acupuncture point. The acquisition of these signals was performed utilizing an electronic interface with a computer, which was based on an instrumentation amplifier designed with adequate specifications to this end. On the collected signals from a sample of 30 volunteers we have calculated major statistics and submitted them to pairing t-test with significance leveI a = O, 05. We have estimated to bioelectric signals the following parameters: standard deviation, asymmetry and curtose. Moreover, we have calculated the self-correlation function matched by on exponential curve we have observed that the signal decays more rapidly from a non-acupoint then from an acupoint. This fact is an indicative of the existence of information in the acupoint / Ao longo do s?culo XX o uso da acupuntura passou a se disseminar no mundo Ocidental como pr?tica complementar de sa?de. Este fato tem motivado a comunidade cient?fica internacional a investir em pesquisas que buscam compreender por que a acupuntura funciona. Nesta disserta??o comparamos estatisticamente a flutua??o de voltagem de sinais bioel?tricos captados sobre a pele em um ponto de acupuntura (IG 4) e outro ponto pr?ximo de n?o-acupuntura. A aquisi??o desses sinais foi realizada utilizando uma interface eletr?nica com um computador, a qual foi baseada em um amplificador de instrumenta??o projetado com as especifica??es adequadas a este fim. Sobre os sinais coletados de uma amostra de 30 volunt?rios calculamos as estat?sticas relevantes e as submetemos ao teste t-pareado com n?vel de signific?ncia a = 0,05. Estimamos para o sinal bioel?trico as seguintes grandezas: desvio padr?o, assimetria e curtose. Al?m disso, calculamos a fun??o de auto-correla??o que foi ajustada por uma curva exponencial. Observamos que o sinal decai mais rapidamente no n?o-acuponto do que no acuponto. Tal fato ? um indicativo da presen?a de informa??o no acuponto
2

An?lise estat?stica das emiss?es de CO e HC produzidas por gases da exaust?o veicular oriundos de gasolina, GNV e mistura ?lcool/gasolina

Fernandes, C?liton de Souza 13 July 2009 (has links)
Made available in DSpace on 2014-12-17T14:57:49Z (GMT). No. of bitstreams: 1 CelitonS.pdf: 1872654 bytes, checksum: 0e3a2fa3a25b2b0d3f6314fb9f1b6ab9 (MD5) Previous issue date: 2009-07-13 / The vehicles are the main mobile sources of carbon monoxide (CO) and unburned hydrocarbons (HC) released into the atmosphere. In the last years the increment of the fleet of vehicles in the municipal district of Natal-RN it is contributing to the increase of the emissions of those pollutants. The study consisted of a statistical analysis of the emissions of CO and HC of a composed sample for 384 vehicles with mechanization Gasoline/CNG or Alcohol/Gasoline/CNG of the municipal district of Natal-RN. The tests were accomplished in vehicles submitted to Vehicular Safety's Inspection, in the facilities of INSPETRANS, Organism of Vehicular Inspection. An partial gases analyzer allowed to measure, for each vehicle, the levels of CO and HC in two conditions of rotation of the motor (900 and 2500 rpm). The statistical analysis accomplished through the STATISTICA software revealed a sensitive reduction in the efficiency of the converters catalytic after 6 years of use with emission average it is of 0,78% of CO and 156 (ppm) of HC, Which represents approximately 4 (four) times the amount of CO and the double of HC in comparison with the newest vehicles. The result of a Student s t-test, suggests strongly that the average of the emissions of HC (152 ppm), at 900 rpm, is 40% larger than at 2500 rpm, for the motor without load. This result reveals that the efficiency of the catalytic conversion is limited kinetically in low engine speeds. The Study also ends that when comparing the emissions of CO and HC considering the influence of the fuels, it was verified that although the emissions of CO starting from CNG are 62% smaller than arising from the gasoline, there are not significant differences among the emissions of HC originating from of CNG and of the gasoline. In synthesis, the results place the current criteria of vehicular inspection, for exhaust gases, in doubt, leading the creation of emission limits of pollutant more rigorous, because the efficiency of the converters catalytic is sensibly reduced starting from 6 years of use. It is also raised the possibility of modifications in the test conditions adopted by the current norms, specifically in the speed engine, have seen that in the condition without load the largest emission indexes were registered in slow march. That fact that allows to suggest the dismissal of the tests in high speed engine, reducing the time of inspection in half and generating economy of fuel / Os ve?culos automotores s?o as principais fontes m?veis de Mon?xido de Carbono (CO) e Hidrocarbonetos n?o queimados (HC) lan?ados na atmosfera. Nos ?ltimos anos o acr?scimo da frota de ve?culos no munic?pio de Natal-RN vem contribuindo para o aumento das emiss?es desses gases poluentes. O estudo consistiu de uma an?lise estat?stica das emiss?es de CO e HC de uma amostra composta por 384 ve?culos com motoriza??o a Gasolina/GNV ou ?lcool/Gasolina/GNV do munic?pio de Natal-RN. Os testes foram realizados em ve?culos submetidos ? Inspe??o de Seguran?a Veicular, nas instala??es do INSPETRANS, Organismo de Inspe??o Veicular. Um analisador de gases parcial permitiu medir, para cada ve?culo, os n?veis de CO e HC em duas condi??es de rota??o do motor (900 e 2500 rpm). A an?lise estat?stica realizada por meio do software STATISTICA revelou uma sens?vel redu??o na efici?ncia dos conversores catal?ticos ap?s 6 anos de uso com a emiss?o m?dia de 0,78 % de CO e 156 (ppm) de HC, o que representa aproximadamente 4 (quatro) vezes a quantidade de CO e o dobro de HC em compara??o com os ve?culos mais novos. O resultado de um Teste-T de Student sugere fortemente que a m?dia das emiss?es de HC (152 ppm), a 900 rpm, ? 40% maior que a 2500 rpm, para o motor sem carga. Esse resultado revela que a efici?ncia da convers?o catal?tica ? limitada cineticamente em baixas rota??es. O Estudo conclui tamb?m que ao comparar as emiss?es de CO e HC, considerando a influ?ncia dos combust?veis, verificou-se que embora as emiss?es de CO a partir do GNV sejam 62% menores do que a partir da gasolina, n?o h? diferen?as significativa entre as emiss?es de HC oriundas do GNV e da gasolina. Em s?ntese, os resultados colocam os atuais crit?rios de inspe??o veicular, para gases da exaust?o, em d?vida, conduzindo a cria??o de limites de emiss?o de poluentes mais rigorosos, visto que a efici?ncia dos conversores catal?ticos ? sensivelmente reduzida a partir de 6 anos de uso. Suscita-se tamb?m a possibilidade de modifica??es nas condi??es de teste adotadas pelas normas atuais, especificamente na rota??o do motor, haja vista que na condi??o sem carga os maiores ?ndices de emiss?o foram registrados em marcha lenta. De ante disso, sugere-se a dispensa dos testes em altas rota??es, reduzindo ? metade o tempo de inspe??o e gerando economia de combust?vel

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