Made available in DSpace on 2014-10-09T12:33:28Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:37Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP; Faculdade de Odontologia, Universidade de Sao Paulo, Sao Paulo

O objetivo deste trabalho foi desenvolver um software, de fácil operação e eficiente, para determinar a difusividade térmica de biomateriais. A necessidade de se conhecer a difusividade térmica de materiais como, por exemplo, esmalte e dentina, é essencial para o estabelecimento de protocolos de utilização clínica laser, para evitar danos colaterais ao paciente. O software desenvolvido, denominado CZ ThermaDiff, baseia-se no processamento de imagens térmicas adquiridas por uma câmera termográfica no infravermelho (ThermaCam SC3000, FLIR System, EUA). Foi desenvolvido em ambiente LabView, o que permitiu criar um painel de controle de fácil operação, contendo apenas duas funções básicas (Start e Stop). O software arquiva os dados em formato de tabela contendo todas as medidas de difusividade térmica, suas médias para intervalos de 10 °C e suas respectivas temperaturas, para uma amostra. Foi observado, tanto para o esmalte quanto para a dentina, que os valores de difusividade não são constantes e aumentavam em função da temperatura. Os valores encontrados foram aplicados a um modelo de transferência de calor, simulando um dente molar humano com as seguintes estruturas: esmalte, dentina e polpa. O modelo baseia-se no método de resistores térmicos, sendo que para a polpa foi utilizado o modelo de difusão de calor, considerando a circulação sanguínea. Os valores de temperatura obtidos neste modelo teórico, utilizando difusividades dependentes da temperatura foram maiores que as obtidas com um valor constante de difusividade, medido à temperatura ambiente. Este fato realça a importância da mensuração da difusividade em função da temperatura e da interface desenvolvida neste trabalho. / The aim of this work was to develop a software, easy to operate and efficient, to determine the thermal diffusivity of biomaterials as enamel and dentin. It is necessary to know the thermal diffusivity of these materials to establish laser irradiation protocols, to avoid collateral damage to the patient. The software developed named called CZ ThermaDiff, processes thermographic images from a thermographic camera (ThermaCam SC300, FLIR System, USA). The software was programmed in LabView environment, allowing easy operation from a control window with only two buttons (start and stop). Thermal diffusivity values, the mean values for intervals of 10 °C and its respective temperature, for one sample are saved in table form. For both biomaterials, thermal diffusivity increased as function of the temperature increase. The experimental thermal diffusivity data were used in a heat transfer model, for a human molar tooth with three layers: enamel, dentin and pulp. The model was based on the thermal resistors method, for the three layers and for the pulp, it was applied the heat diffusion model, taking into account the blood circulation. Using temperature dependent diffusivities, temperatures where values were higher than the temperatures of the theoretical model using a constant diffusivity value, obtained at ambient temperature. This fact emphasized the importance of both: the temperature dependent diffusivity measurement and the software developed in this work.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / A crescente demanda por alimentos tem feito com que a agricultura brasileira aperfeiÃoe a sua produÃÃo em campo, levado o operador de tratores agrÃcolas a prolongadas jornadas de trabalho, expondo-o a um ambiente insalubre, alÃm de provocar alguns acidentes e de causar danos à saÃde do operador, ocasionando, em certos casos, atà mesmo morte do profissional. NÃo obstante existam tecnologias capazes de melhorar as condiÃÃes de trabalho do operador, como sÃo as capotas e as cabines climatizadas, a grande maioria dos tratores no Brasil nÃo dispÃem deste dispositivo. Sendo assim, o operador permanece submetido a condiÃÃes ambientais adversas, principalmente na regiÃo do Nordeste, em que, durante todo o ano, os elevados nÃveis de radiaÃÃo solar e temperatura do ar sÃo desfavorÃveis ao conforto tÃrmico e ao bem estar dos operadores de tratores agrÃcolas. Deste modo, tomando por base as condiÃÃes econÃmicas e climÃticas de cada regiÃo, o objetivo deste estudo foi avaliar o conforto tÃrmico e ergonÃmico do operador em tratores agrÃcolas com e sem capota na atividade de preparo de solo, visando apontar diagnÃstico em relaÃÃo à sensaÃÃo tÃrmica, à insalubridade ao calor, o grau de esforÃo fisiolÃgico e medir a temperatura da pele de diferentes membros do corpo deste profissional quando em trabalho. As avaliaÃÃes foram feitas durante o verÃo brasileiro nos perÃodos matutinos, vespertinos e noturnos, utilizando de um trator BM-125I, da marca VALTRA, durante as operaÃÃes de araÃÃo e subsolagem. A sensaÃÃo tÃrmica foi calculada atravÃs da temperatura e da umidade relativa do ar e resultou em desconforto em todas as condiÃÃes trabalhadas. A insalubridade foi calculada baseando-se na metodologia da Norma Regulamentadora n 15, Anexo 3, insalubridade esta que nÃo foi diagnosticada por parte da exposiÃÃo ao calor, dado se ter medido a frequÃncia cardÃaca do operador para anÃlise ergonÃmica e se constatado que nÃo houve sobrecarga cardiovascular nos esforÃos fÃsicos demandados pelas operaÃÃes. Finalmente, foi medida a temperatura mÃdia da pele dos certos membros do operador (face, mÃo, braÃo e perna) fazendo uso de termovisores e levando em consideraÃÃo a permanÃncia do calor acima da temperatura de conforto em todas as condiÃÃes e horÃrios trabalhados, e pode-se notar que houve diferenÃa significativa quanto à variaÃÃo na temperatura da pele do operador entre as condiÃÃes de operaÃÃes realizadas com e sem capota apenas nos os horÃrios do meio dia e ao final da tarde. / The increasing food demand has made Brazilian agriculture optimize their production in the field, conducing the agricultural tractors operator to prolonged working hours exposing him to an unhealthy environment, besides causing some accidents and cause damage to the operator health, causing, in some cases, even professional death. Nevertheless there are technologies that can improve the operator working conditions as are the cowlings and air-conditioned cabins, the great majority of tractors in Brazil donât have this device. Therefore, the operator remains submitted to adverse environmental conditions, especially in the Northeast region, in which, throughout the year, the elevated levels of solar radiation and air temperature are unfavorable for thermal comfort and well-being of agricultural tractor operators. Then, based on the economic and climatic conditions in each region, the objective of this study was to evaluate the thermal and ergonomic operator comfort in tractors with and without cowl in the activity of soil preparation, aiming to identify diagnosis in relation to thermal sensation, heat insalubrity, the physiological stress degree and to measure the skin temperature of different body parts of this person when working. The assessments were made during the Brazilian summer morning, afternoon and evening periods, using a BM-125I tractor VALTRA brand, during plowing and subsoiling operations. The Thermal sensation was calculated using the temperature and relative humidity and resulted in discomfort worked in all conditions. The unhealthiness was calculated based on the methodology of Norma Regulamentadora 15, Anexo 3, unhealthiness this which was not diagnosed by exposure to heat, as it had measured the heart rate operator for ergonomic analysis and verified that there wasnât overload in cardiovascular physical effort demanded by operations. Finally, measured the skin average temperature of some operatorâs member (face, hand, arm and leg) by making use of thermal imaging and considering the permanence of heat above the comfort temperature in all conditions and hours worked, and was noted that there was significant difference in the variation by skin temperature operator between operating conditions with and without cowl only in the schedules of midday and late afternoon.

Made available in DSpace on 2014-10-09T12:33:28Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:37Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP; Faculdade de Odontologia, Universidade de Sao Paulo, Sao Paulo

Pelo fato da face ser uma estrutura que envolve multissistemas, ela é considerada anatomica e funcionalmente muito complexa em sua avaliação clínica. Muitos diagnósticos de doenças que afetam a região facial são realizados por meio de métodos de imagem, entretanto, as técnicas convencionais são incompletas, pois apresentam um déficit de informações em relação aos aspectos funcionais, relativos à microcirculação regional e o sistema nervoso autônomo. Para documentação objetiva destas alterações, a termografia por imagem infravermelha tem sido proposta como método auxiliar diagnóstico. O objetivo deste estudo foi identificar, mapear e quantificar pontos de referência baseados na termoanatomia da face, a partir de gradientes térmicos, em uma população adulta. A amostra constituiu-se por 161 voluntários, ambos os gêneros, entre 26 e 84 anos (63 ±15 anos). Foram identificados 28 pontos de referência termoanatômicos fixos em 94,6% da amostra. A temperatura média desses pontos de referência termoanatômicos variou entre 33,3°C a 35,6°C, sendo que o melhor valor de corte para sua correta identificação na face foi acima de 34,5ºC. Não houve diferença estatística quando os comparou entre as hemifaces correspondentes e nem quanto à idade dos voluntários (?T = 0,11°C), exceto entre os gêneros e grupo racial (p<0,05). Concluiu-se que a face apresenta pontos termoanatômicos fixos e confiáveis em adultos, a qual a termografia tem o potencial de auxiliar na identificação de alterações a partir destes pontos. / Anatomical and functional information of the structures of interest are the basis for interpretation of imaging exams. For recognizing diseases it is necessary to understand and identify the anatomical structures and its variations. Diagnosis of some facial diseases may be done through medical imaging techniques; however, the most conventional methods present lack of information regarding physiological and functional aspects such as microcirculation and autonomous nervous system. The aim of this study was to identify, map and quantify the facial thermal gradients (thermo-anatomical points) in healthy adult population. A hundred sixty-one volunteers of both gender and mean age of 63 ±15 years were included. The results showed that twenty eight thermo-anatomical points have been identified in 94.6% of the sample, with a significant difference of the temperature in gender and racial groups (p<0.05). Moreover, there was no statistically significant difference between ages and sides in healthy individuals (?T = 0.11°C). The average temperature of the points ranged from 33.3°C to 35.6°C. When the maximum temperature reached to detect a facial thermal gradient is higher than 34.5°C, the thermo-anatomical point is meant to be correctly delineated. For detection of functional changes from thermoanatomical points on the face, thermography may be used as an auxiliary diagnostic imaging method.

A grande casuística relacionada à afecção ortopédica denominada ruptura do ligamento cruzado cranial na articulação fêmoro tíbio patelar canina tem gerado diversos estudos avaliando a biomecânica articular, fatores extrínsecos ao paciente e características metabólicas que poderiam influenciar na predisposição e no prognóstico dos pacientes acometidos por esta afecção. As dificuldades em identificar os diferentes níveis de instabilidade articular durante o diagnóstico e de estabilidade após o tratamento proposto, seja cirúrgico ou conservativo, provocou o desenvolvimento de diversas técnicas visando um melhor diagnóstico e estabilização articular pós operatória. Apesar da ampla variedade de técnicas cirúrgicas atualmente descritas para a insuficiência do ligamento cruzado cranial (LCC) em cães o tratamento ideal para esta freqüente condição ortopédica permanece indeterminado. Foram avaliados através da termografia infravermelha 30 pacientes caninos acima de 20 quilos sendo divididos em três grupos, o primeiro composto por dez animais hígidos onde foram analisados termograficamente os joelhos bilaterais a fim de padronizar valores térmicos de joelhos caninos normais, o segundo grupo composto por dez pacientes diagnosticados com instabilidade da articulação fêmoro tíbio patelar unilateral que foram submetidos a técnica cirúrgica de TTA para estabilização articular e o terceiro grupo composto por dez animais com diagnóstico de instabilidade da articulação fêmoro tíbio patelar unilateral que foram submetidos a técnica cirúrgica de TPLO para estabilização articular. Os grupos TTA e TPLO foram avaliados termograficamente em período pré operatório e nos momentos 30, 60 e 90 dias de pós operatório. Aos 30 dias de pós operatório houve diferença estatística com o grupo TPLO obtendo valores superiores ao grupo TTA. No período de 60 e 90 dias, não encontramos diferenças estatisticamente significantes nos valores comparativos dos membros operados em relação ao contralateral hígido podendo indicar que as duas técnicas cirúrgicas são capazes de trazer a articulação operada a uma condição de normalidade do ponto de vista termográfico. / The large number of cases related to the orthopedic condition called cranial cruciate ligament rupture in dogs has generated several studies evaluating the joint biomechanics, metabolic and environment characteristics that could influence the susceptibility and prognosis of patients affected by this condition. The difficulties in identifying the different levels of joint instability during diagnosis and joint stability after surgical or conservative treatment led to the development of several surgical techniques aiming a better diagnosis and joint stabilization. Despite the wide variety of surgical techniques currently described for the insufficiency of the cranial cruciate ligament (CCL) in dogs the ideal treatment for this common orthopedic condition remains uncertain. We evaluated using infrared thermography 30 canine patients over 20 kg. They were separated into three groups: the first group were consisted of ten healthy dogs, where we evaluated thermographycally their bilateral stifle in order to acquire thermal values of normal canine knees, the second group had ten patients diagnosed with instability of one stifle and were operated using the surgical technique called TTA and the third group were consisted of ten animals with a diagnosis of instability of unilateral stifle who underwent surgical procedure using the surgical technique called TPLO. The TTA and TPLO groups were evaluated thermographycally before surgery and at times 30, 60 and 90 days postoperatively. At 30 days evaluation we found significant differences between the TPLO and the TTA groups. At 60 and 90 days evaluation there were no significant differences between the operated limb in both groups and their contralateral not affected stifle. This results may indicate that both surgical techniques can bring the stifle back to normal thermographic parameters.

Abstract Despite the large amount of research work in condition based maintenance and condition monitoring methods, there is still a need for more reliable and accurate methods. The clear evidence of that need is the continued dependence on time based maintenance, especially for critical applications such as turbomachinery and airplane engines. The lack of accurate condition monitoring systems could lead to not only the unexpected failures as well as the resulting hazards and repair costs, but also a huge waste of material and time because of unnecessary replacement due to false alarms and unnecessary repair and maintenance. Temperature change is a phenomenon that accompanies every dynamic activity in the universe. However, it has not been adequately exploited for mechanical system condition monitoring. The reason is the slow response of current temperature monitoring systems compared to other condition monitoring methods such as vibration analysis. Many references inferred that the change in temperature is not sensible until approaching the end of the monitored component life and even the whole system life (Kurfess, et al., 2006; Randall, 2011; Patrick, et al., March 7-14, 2009). On the other hand, the most commonly used condition monitoring method, i.e., vibration analysis, is not free from pitfalls. Although vibration analysis has shown success in detecting some bearing faults, for other faults like lubrication problems and gradual wear it is much less effective. Also, it does not give a reliable indication of fault severity for many types of bearing faults. The advancement of thermography as a temperature monitoring tool encourages the reconsideration of temperature monitoring for mechanical system fault detection. In addition to the improved accuracy and responsiveness, it has the advantage of non-contact monitoring which eliminates the need for complex sensor mounting and wiring especially for rotating components. Therefore, in current studies the thermography-based monitoring method is often used either as a distinct method or as a complementary tool to vibration analysis in an integrated condition monitoring system. The main objectives of this study are hence to: 1. Define heat sources in the rolling element bearings and overview two of the most famous bearing temperature calculation methods. 2. Setup a bearing test rig that is equipped with both vibration and temperature monitoring systems. 3. Develop a temperature calculation analytical model for rolling element bearing that include both friction calculation and heat transfer models. The friction calculated by the model will be compared to that calculated using the pre-defined empirical methods. The heat transfer model is used for bearing temperature calculation that will be compared to the experimental measurement using different temperature monitoring devices. 4. Propose a new in-band signal enhancement technique, based on the synchronous averaging technique, Autonomous Time Synchronous Averaging (ATSA) that does not need an angular position measuring device. The proposed method, in addition to the Spectral Kurtosis based band selection, will be used to enhance the bearing envelope analysis. 5. Propose a new method for classification of the bearing faults based on the fault severity and the strength of impulsiveness in vibration signals. It will be used for planning different types of tests using both temperature and vibration methods. 6. Develop and experimentally test a new technique to stimulate the bearing temperature transient condition. The technique is supported by the results of finite element modeling and is used for bearing temperature condition monitoring when the bearing is already running at thermal equilibrium condition.

The effects of fin-leading-edge radius and sweep angle on peak heating rates due to shock-shock interactions were investigated in the NASA Langley Research Center 20-inch Mach 6 Air Tunnel.  The fin model leading edges, which represent cylindrical leading edges or struts on hypersonic vehicles, were varied from 0.25 inches to 0.75 inches in radius.  A 9° wedge generated a planar oblique shock at 16.7° to the flow that intersected the fin bow shock, producing a shock-shock interaction that impinged on the fin leading edge.  The fin angle of attack was varied from 0° (normal to the free-stream) to 15° and 25° swept forward.  Global temperature data was obtained from the surface of the fused silica fins through phosphor thermography.  Metal oil flow models with the same geometries as the fused silica models were used to visualize the streamline patterns for each angle of attack.  High-speed zoom-schlieren videos were recorded to show the features and temporal unsteadiness of the shock-shock interactions.  The temperature data were analyzed using one-dimensional semi-infinite as well as one- and two-dimensional finite-volume methods to determine the proper heat transfer analysis approach to minimize errors from lateral heat conduction due to the presence of strong surface temperature gradients induced by the shock interactions.  The general trends in the leading-edge heat transfer behavior were similar for the three shock-shock interactions, respectively, between the test articles with varying leading-edge radius.  The dimensional peak heat transfer coefficient augmentation increased with decreasing leading-edge radius.  The dimensional peak heat transfer output from the two-dimensional code was about 20% higher than the value from a standard, semi-infinite one-dimensional method. / Master of Science

No description available.

Quick, efficient, and reliable methods for in-service inspection of rails to ensure the safety of transportation is an open challenge in the railroad industry. It is well known that fatigue cracks are the leading cause of derailments. Furthermore, new high-speed and heavy-load trains have seen increased use, leading to an increase in the loads and number of cycles experienced by a given section of track. Additionally, most methods for inspecting rails require that sections of the track be shut down for inspection. As a result, much industry attention has been paid to the development of nondestructive methods for inspecting whole sections of the track, although a significant gap in inspection needs and capabilities exists, especially with the inspection of rail base. This studied the feasibility of applying Line Scan Thermography (LST) toward detecting defects in the rail base using Finite Element Analysis (FEA) validated by analytical solutions and experiments and simulated the LST inspection in multiple models at speeds up to 40 mph. In the simulations, subsurface fabricated defects were considered to correlate the necessary thermal contrast, amount of energy, and scan speed. The digital twins, when compared to experimental results, showed the same trend. The rail base section model was simulated with 6000 W of heat, and scanning speeds varying from 0.3 mph up to 40 mph with a 150 mm distance showed an exponential decrease in the thermal contrast. However, when the heat power and camera location are changed proportionally to the speed increase, the thermal contrast remains within a change of 1% and 16% for the detectable reflectors. Moreover, the technique was considered feasible if the previous relationship was respected. Further studies regarding this application account for a deeper investigation of this scanning speed and energy relation, developing a Computational Fluid Dynamics model of this problem, and testing samples with surface defects.