Dissertations / Theses on the topic 'Light and Heat'

Canadian intellectual Marshall McLuhan (1911--1980) left a controversial legacy. This dissertation addresses the four chief paradoxes that his work poses for contemporary commentators: the core meaning of his texts; the tradition in which his contribution now seems most intelligible; the divergent response to his work; and the enduring yet fragmentary impact of his contribution to popular and academic life. Taking a rhetoric of inquiry approach, modified by Gerald Holton's writing in the history of science, this reappraisal argues for McLuhan's significance as a theorist of communications as techno-cultural transformation or "mediamorphosis"; for his seminal role within the Toronto School of Communications; and for his inspiring relevance within the interdiscipline of communications, despite the forging of a negative academic consensus against his work in the early 1970s. McLuhan united the ancient arts of grammar and rhetoric into a techno-cultural hermeneutics that constitutes an unexhausted approach to the study of the impacts of media and technologies on sensibilities, literacies and culture.

Regular physical activity is recommended in healthy pregnancies and has been shown to mitigate adverse pregnancy outcomes. Despite the benefits, many women do not adhere to the recommendations due to concerns of exercise-induced heat stress and the dangers it could pose to the developing fetus. While the majority of the concerns raised are not grounded in evidence, currently there are no studies that directly examine the isolated influence of pregnancy on metabolic heat production resulting from physical activity. Additionally, despite the prevalent use of psycho-physical tools in clinical settings, there is a scarcity of literature exploring the relationship between the physiological and perceptual measures of exercise-induced heat strain in the pregnant population. Therefore, objective one of this thesis was to quantify the heat production resulting from light to moderate physical activity (intensities recommended during pregnancy) throughout gestation. Secondly, in objective two, physiological and perceptual measures of thermal strain were compared and assessed throughout pregnancy. In evaluating the change in heat production resulting from exercise (objective one), 10 non-pregnant control (30±1 yrs; BMI=22.3±0.8 kg/m2) and 10 pregnant (32±1 yrs; pre-pregnancy BMI=22.8±0.8 kg/m2) women performed a seven stage submaximal walking test in a thermal controlled chamber (23ºC). Testing was performed during their 1st (T1, 12-16 wks), 2nd (T2, 24-28 wks) and 3rd (T3, 34-38 wks) trimester of pregnancy while metabolic heat production was measured through indirect calorimetry. To assess the changes in thermal and perceptual strain (objective two), 16 non-pregnant control (32±1 yrs; BMI=22.7±0.7 kg/m2), and 20 pregnant (32±1; pre-pregnancy BMI=23.2±0.6 kg/m2) women underwent a graded walking exercise protocol at T2 and T3. Over the course of this test, heart rate, tympanic temperature (Ttymp), skin temperature (Tskin), rate of perceived exertion (RPE, 20-point scale) and thermal sensation (9-point scale) were assessed. Findings from this thesis show that for the same given progressive exercise test, women in T1 experienced similar metabolic heat production to their non-pregnant counterparts. However, as pregnancy progressed, women exhibited on average, a 7-8% increase in heat production per trimester of pregnancy that can be accounted for by weight gain. Further, at baseline conditions, heart rate responses increased with pregnancy, while Ttymp remained unchanged and Tskin decreased. In response to exercise, the magnitude of change in heart rate, Ttymp and Tskin did not differ between gestational conditions. Finally, a strong correlation was identified between heart rate and RPE throughout pregnancy, while thermal sensation only directly correlated with Ttymp and not Tskin. Overall, the present findings suggest that while the same progressive exercise test results in greater levels of heat production as pregnancy progresses, this is not observed in physiological or perceptual measures of heat strain. Rather, findings of this thesis support the notion of improved thermoregulatory responses to account for the increase in metabolic heat production. Moreover, the present thesis provides support for the use of the RPE and thermal sensation scales as effective psycho-physical tools in the pregnant population under conditions of light to moderate exercise in normothermic conditions.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Graham, Samuel; Committee Member: Joshi, Yogendra; Committee Member: Kumar, Satish. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Introduction One of the products made by SAAB Avionics Systems in Jönköping was in need of a better cooling solution. The product, a Head-Up Display, holds a LED that was overheating when run at desired input power. The purpose of this thesis was to identify the design weaknesses in the current solution regarding heat dissipation and produce new design proposals that fulfill the requirements. The parts analyzed consist of a LED light source, adjustment plates and a heat sink. The adjustment plates and heat sink where covered in a surface treatment. Theoretical framework A simulation of a finite element model was set up of the current solution in order to identify the influence of the different parts and their thermal properties. The simulation was set up as a steady state thermal model. The FEM and steady state equations used during this are mentioned and shortly explained. The state of modern research was found in order to find new innovative ways of solving the heat problem. Method In order to understand the current solution, experimentswere carried out. Interviews were used in order to get the correct information easily. A literature study was preformed to understand the different theories. Reverse engineering was applied to get a detailed understanding of the functionality both mechanically and thermally. Brainstorming was used to generate new solutions, which was followed by a feasibility evaluation and Pugh’s method to sort out the best concepts. Implementation and Result Based on the simulations it can be concluded that some of the developed solutions pass the requirements and can be implemented right away. Some need some more work in order to fully pass the demands. Conclusions The thermal flow was greatly affected by the properties of the aluminum in the adjustment plates and heat sink, though there was not much room for thickness reduction. However, the oxide layer and the surface roughness also had a great impact on the high junction temperature. The requirements where therefore met when adjustment plates and interfaces were removed, to lower the amount of oxide and air between the LED and the heat sink. But the oxide layers needed to be thinner and the surface roughness needed to be reduced in order to meet requirements. If the oxide layers need to stay at current thickness or the surface roughness cannot be changed, the heat sink needs to be redesigned. The recommended concepts were smaller than the current solution. If this space is utilized with a bigger heat sink, the goals can be met with greater ease. There is also room for improvement when it comes to heat sink heat spreader pattern. Discussion The discussion covers what knowledge which was needed to write this thesis and how different problems that occurred along its path were solved. Sustainability in different ways was also discussed.

Kyoto University (京都大学)
0048
新制・課程博士
博士(人間・環境学)
甲第13928号
人博第401号
新制||人||99(附属図書館)
19||人博||401(吉田南総合図書館)
UT51-2008-C844
京都大学大学院人間・環境学・環境学研究科相関環境学専攻
(主査)准教授 酒井 敏, 教授 鎌田 浩毅, 教授 宮本 嘉久
学位規則第4条第1項該当

We can trace the beginnings of our knowledge of early Upper Paleolithic (Aurignacian) use of fire to the pioneering 1910-1911 excavations at Abri Blanchard undertaken by Louis Didon and Marcel Castanet. At Blanchard, the excavators recognized and described fire structures that correspond in many ways to features excavated more recently in Western and Central Europe. Here, we address the issue of heat and light management in the early Upper Paleolithic, demonstrating a pattern that builds on these early excavations but that is refined through our recent field operations. Topics to be discussed include (1) recently excavated fire structures that suggest complex fire management and use, (2) the seemingly massive use of bone as fuel in most early Aurignacian sites, and (3) the anchoring of skin structures for purposes of heat retention with fireplaces behind animal-skin walls. Furthermore, new data on activities around fireplaces make it possible to infer social and organizational aspects of fire structures within Aurignacian living spaces. The vast majority of early Aurignacian occupations, most of them now dated to between 33,000 and 32,000 BP (uncalibrated), occurred on a previously unoccupied bedrock platform into which the occupants dug their fire features.

Summary The development of urbanization and industrialization has improved the comfort level and the quality of human’s life effectively. But at the same time, it also caused many global environment problems, such as air pollution, greenhouse effect and urban heat island (UHI).  The environment cannot keep the balance because of lots of industrial activities, anthropogenic heat and building surface effect. Almost 3 billion people, who are living in cities, have to face this situation, and the quantity is still increasing. The authors use literature research methodology, case study, comparative study and trend analysis study while writing. UHI have a harmful effect (such like photochemical smog and increasing energy use) on urban ecological environment, daily life and health. As the product of urbanization and industrialization, UHI has become one of the most important climate issues. Urban green space is helpful to reduce urban heat islands. London has a better urban green space system to face UHI and Hong Kong still has a long way to improve the green environment for reduce UHI. This article consider that roof greening is a suitable method to help Hong Kong gets rid of urban heat islands. And the lighting and population could indicate the level of urbanization, also can reflect the effect of urban heat islands preliminary. Over-capitalized lighting will exacerbate urban heat islands.

Shale barrens are unique habitats located throughout the southern Appalachians. They are characterized by a south or south west aspect, a steep slope, and an exposed rocky surface (Platt, 1951). They have a high total irradiance and can experience temperatures higher than the surrounding deciduous forest. A variety of plant species, several of which are rare or endangered, are endemic to the shale barren habitat. One reason proposed fc)r their endemism is that the plants are obligate heliophyt:es (Keener, 1983). The purpose of this dissertation is tel examine the acclimation ability of the shale barren endemic Eriogonum alIeni to shade and high temperature.
Ph. D.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2010.
Committee Chair: Samuel Graham; Committee Member: J. Rhett Mayor; Committee Member: Yogendra Joshi. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Beta lactoglobulin (βlg) is a major whey protein in the bovine milk. Upon heating above its denaturation temperature (which is pH-dependent), this globular protein undergoes molecular changes leading to the irreversible aggregation. Depending on the pH and ionic strength, either protein aggregates or gels exhibiting various structures and morphologies have been described. Very recently, it was found that in a narrow range of the pH close to iso-electric point, stable suspensions of rather monodisperse spherical particles with a radius of about a hundred nanometers were formed. These spherical particles which were called microgels might be of special interest for the production of liquid dispersions of β-lactoglobulin aggregates exhibiting various functionalities for food applications. The project on which I report here was a collaboration with the Nestlé Reseach Center (Lausanne, Switzerland) and its objective was to study the formation and structural properties of the microgels in different environmental conditions. The first part of the project is to study the influence of the pH on the formation of microgels. Stable suspensions of protein microgels are formed by heating salt free βlg solutions at concentrations up to about C = 50 g.L-1 if the pH is set within a narrow range between 5.75 and 6.1. The internal protein concentration of these spherical particles is about 150 g.L-1 and the average hydrodynamic radius decreases with increasing pH from 200 nm to 75 nm. The formation of the microgels leads to an increase of the pH, which is a necessary condition to obtain stable suspensions. The spontaneous increase of the pH during microgel formation leads to an increase of their surface charge density and inhibits secondary aggregation. This self-stabilization mechanism is not sufficient if the initial pH is below 5.75 in which case secondary aggregation leads to precipitation. Microgels are no longer formed above a critical initial pH, but instead short curved protein strands are obtained with a hydrodynamic radius of about 15-20 nm. The second part of the work is about the formation of microgels driven by the addition of calcium ions. We found that stable suspensions of spherical protein particles (microgels) can be formed by heating βlg solutions in the presence of calcium ions. The conditions for the calcium induced microgel formation were studied at different pH between 5.8 and 7.5 and different protein concentrations between 5 - 100 g.L-1. The results showed that a critical molar ratio of calcium to proteins (R) is needed to form microgels independent of the protein concentration. R decreases with decreasing pH. The microgels have a hydrodynamic radius ranging from 100 to 300 nm and their internal protein concentration ranges from 0.2 to 0.45 g.mL-1. The determination of calcium bound to the microgels suggests that the crucial parameter for microgel formation is the net charge density of the native proteins. The microgel suspensions are stable in a narrow range of R but aggregate at higher Ca2+ concentrations. In the third part, we continued to investigate the formation of microgels at initial step and how it is growing in the presence of calcium ions. We have proposed a mechanism of formation of blg microgels which follows a nucleation and growing process. The nucleus with define size are formed at the initial state and that is growing in size to reach final size of aggregates. At low calcium concentration it stabilizes and then we obtain a stable suspension of microgels. But at high concentrations, the microgels here can jump to form big aggregates and finally a gel. The structure of gel from microgels is heterogenous at the scale of confocal microscopy and similar to those formed in the presence of NaCl 0.3 M. However the process of formation of these gels is not the same...

This thesis examines droplets striking water repelling surfaces as well as the movement of a soil based bacteria under various light and heat conditions. Droplet impact studies have shown that introducing a macroscopic feature to a water repelling surface can reduce the amount of time that droplet is in contact with the surface. By manipulating water droplets to impact different sized needles at varying speeds, we present how a needle can induce a similar reduction in the residence time of the droplet to more widely studied features. Results show the spreading and lift-off characteristics of the droplet are dependent on the impact speed as well as the size of macroscopic feature. A separate topic examines environmental motivators for mobility in a terrestrial cyanobacteria species called Microcoleus vaginatus. This cyanobacteria is indigenous to cold deserts, such as the Colorado Plateau or Mojave Desert in North America, and is essential to the health and preservation of the biological soil crust. These bacteria are the first organisms to grow in new soil, secreting a carbohydrate that acts as soil glue, thereby increasing soil adhesion. It has been shown that these bacteria will rise to the surface of the soil from their subsurface homes after rainfall, but it is unclear how they are able to make this journey. It is also unclear if other factors, such as nutrient levels or heat and light, affect their movement. Here we present an investigation of M. vaginatus’ response to light and heat in order to determine if these basic stimuli affect movement, thereby informing future restorative models.

It is the objective of this work to focus on heat dissipation in gallium nitride based solid-state logic devices as well as optoelectronic devices, a major technical challenge. With a direct band gap that is tunable through alloying between 0.7-3.8 eV, this material provides an enabling technology for power generation, telecommunications, power electronics, and advanced lighting sources. Previously, advances in these areas were limited by the availability of high quality material and growth methods, resulting in high dislocation densities and impurities. Within the last 40 years improvements in epitaxial growth methods such as lateral epitaxial overgrowth (LEO), hydride vapor phase epitaxy (HVPE), molecular beam epitaxy (MBE), and metal organic chemical vapor deposition (MOCVD), has enabled electron mobilities greater than 1600 cm2V/s, with dislocation densities less than 109/cm2. Increases in device performance with improved materials have now been associated with an increase in power dissipation (>1kW/cm2) that is limiting further development. In the following work thermophysical material of III-V semiconducting thin films and associated substrates are presented. Numerical modeling coupled with optical (micro-IR imaging and micro-Raman Spectroscopy) methods was utilized in order to study the heat carrier motion and the temperature distribution in an operating device. Results from temperature mapping experiments led to an analysis for design of next generation advancements in electronics packaging.

Orientador: Ariene G. F. Van Dender
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
Made available in DSpace on 2018-08-05T11:39:20Z (GMT). No. of bitstreams: 1 Gallina_DarlilaAparecida_D.pdf: 2393198 bytes, checksum: d449f75bf565f0dfc3ba0c2977c57919 (MD5) Previous issue date: 2005
Resumo: Neste trabalho otimizou-se o processo de obtenção do requeijão cremoso longa vida (UHT) com teor integral de gordura e desenvolveu-se o processo tecnológico de fabricação do requeijão cremoso light UHT, de modo a obter produtos com características similares às versões tradicional e light obtidas com tratamento térmico normal. Os requeijões cremosos foram processados a partir de massa obtida por acidificação direta a quente de leite desnatado. Creme de leite, sal emulsificante e cloreto de sódio foram adicionados a massa antes de iniciar o processo de fusão. No caso das versões light a gordura foi parcialmente substituída pelo concentrado de proteína de soro (WPC 34%). Os requeijões obtidos foram envasados em copos de vidro (requeijão cremoso e requeijão cremoso light) ou esterilizados em processo UHT (143ºC/3-5 segundos) e envasados assepticamente em embalagens Tetra Pak de 125 mL (requeijão cremoso UHT e light UHT). Os requeijões obtidos foram avaliados e comparados em relação às características: físicas e químicas, microbiológicas, perfil de textura (TPA), sensoriais (aceitabilidade, ADQ, estudo de vida de prateleira), perfil eletroforético das proteínas, microscopia eletrônica de varredura (SEM) e cor (instrumental). Não houve diferença significativa (p < 0,05) na composição química do requeijão cremoso (RC) e requeijão cremoso UHT (RCUHT). Os requeijões cremosos light (RCL) e light UHT (RCLUHT) apresentaram composição bastante similar. Ao longo do período de estocagem de 90 dias a 5ºC os valores de pH e lactose dos requeijões cremosos (RC e RCUHT) não apresentaram diferença significativa. Os índices de oxidação lipídica pelo método de ácido 2-tiobarbitúrico (TBA) do RC foram significativamente maiores do que os do RCUHT em 30, 60 e 90 dias de estocagem a 5ºC. Não houve diferença significativa no índice de TBA do RCUHT (estocado a 5 e 25ºC) durante o período de estocagem de 180 dias, exceto após 135 dias de estocagem. Nenhuma alteração foi observada no RC e RCL (acondicionados em copo), mantidos a 4-5ºC durante 90 dias, os quais apresentaram qualidade microbiológica satisfatória e de acordo com a legislação vigente. Quando submetidos ao teste de incubação (35-37ºC/7dias), RCUHT e o RCLUHT não apresentaram crescimento microbiano, alteração no pH e na aparência visual sendo, portanto considerados microbiológicamente seguros e adequados ao consumo. Houve diferença significativa (p < 0,05) em todos os parâmetros do perfil de textura (firmeza, adesividade, elasticidade e coesividade) entre o RC e o RCUHT durante 90 dias a 5ºC. Em geral não houve diferença significativa nos atributos de textura do requeijão cremoso UHT e do requeijão cremoso light UHT quando estocados nas temperaturas de 5 e 25ºC. Não houve diferença significativa (p < 0,05) nos parâmetros de cor (Luminosidade, cor amarela e índice de brancura) dos requeijões (RC e RCUHT, e RCL e RCLUHT) durante 90 dias de estocagem a 5ºC, dos requeijões (RCUHT e RCLUHT estocados a 5 e 25ºC) durante 180 dias de estocagem. A interação entre as amostras (RC e RCUHT) e o tempo de estocagem não foi significativa, ou seja, o tratamento térmico aplicado às amostras não afetou significativamente, o pH e o teor de lactose, os parâmetros de textura e os parâmetros de cor dos requeijões durante 90 dias a 5ºC. Para o RCL e o RCL UHT, a interação entre as amostras e o tempo de estocagem não foi significativa para os parâmetros de textura e de cor dos requeijões. Não houve interação significativa entre as amostras (estocadas a 5 e 25ºC) e o tempo de estocagem, ou seja, as temperaturas de estocagem dos requeijões (5 e 25ºC) não afetaram significativamente o índice de TBA, os parâmetros de cor e os parâmetros de textura do RCUHT e do RCLUHT durante 180 dias a 5 e 25ºC. Na microscopia eletrônica de varredura observaram-se diferenças na microestrutura do RC e do RCUHT e também na microestrutura do RCL e RCLUHT. Tais diferenças provavelmente se devem aos efeitos dos tratamentos (térmico e mecânico) inerentes ao processo UHT. Apesar da composição química similar, as diferenças observadas na textura e na microestrutura dos requeijões cremosos (UHT e light UHT) foram desejáveis e necessárias de forma que o produto pudesse ser acondicionado na embalagem e manipulado facilmente para seu consumo. O perfil eletroforético dos requeijões (RC e RCUHT) apresentou as frações da ß-CN, as1-CN e ?-CN. No requeijão cremoso (RC) observou-se também a presença da fração as1 - I CN, além das outras frações. Não houve diferença no perfil eletroforético das proteínas no requeijão cremoso light e requeijão cremoso light UHT, os quais apresentaram as frações de ß-CN, as1-CN e ?-CN. Ao longo do período de estocagem de 90 dias para o requeijão cremoso e light e 180 dias para o requeijão cremoso UHT e light UHT não houve alteração no perfil eletroforético, indicando que não ocorreu proteólise ou degradação das frações de caseína ao longo do tempo. No teste de aceitabilidade das amostras de RC e RCUHT em comparação com amostras comerciais observou-se que todas as amostras obtiveram boas médias de aceitação global. Quanto à consistência e espalhabilidade observaram-se elevadas porcentagens de rejeição da amostra UHT em relação às demais, sendo sua consistência de menor aceitação. Por outro lado, as amostras de RCL e RCLUHT comparadas com amostras de requeijões cremosos light comerciais no teste de aceitabilidade foram as de maior aceitação global. Quanto à consistência e espalhabilidade, houve destaque positivo para aceitação das amostras de RCLUHT e RCL em relação às demais. Em relação ao sabor, o RCLUHT obteve o maior índice de aceitação entre as amostras. Na Análise descritiva quantitativa verificou-se que a amostra de RCUHT em relação ao RC apresentou (ao nível de erro de 5%) cor branco-creme mais escura, menos consistência, mais fluidez, mais escorrimento no pão, menor sensação de corpo/consistência oral e gosto ácido levemente mais intenso. Estas amostras apresentaram igual intensidade de aroma e de sabor característico de requeijão e de creme de leite, de aroma de queijo maturado e de gostos salgado e amargo. A amostra de RCLUHT em relação ao RCL somente diferiu (ao nível de erro de 5%) quanto à intensidade do sabor característico de requeijão, considerada levemente menor. De acordo com o estudo da vida de prateleira e tendo em mente a necessidade de uma margem de segurança que garanta a qualidade do produto sugere-se os seguintes prazos de validade; (1) requeijão cremoso UHT (longa vida): 6 meses sob refrigeração até 10º C; 5 meses a 25º C e 2 meses para estocagem a 35º C; (2) requeijão cremoso light UHT (longa vida): 6 meses sob refrigeração até 10º C; 4 meses a 25º C e 2 meses para estocagem a 35º C. O emprego do processo UHT na produção de requeijão cremoso visa aumentar a durabilidade do produto devido ao tratamento térmico (UHT) e a embalagem asséptica e simplificar o sistema de transporte e estocagem do mesmo, sem a necessidade de refrigeração. Portanto, esta nova tecnologia desenvolvida visa oferecer uma nova alternativa ao mercado consumidor
Abstract: This research study describes the optimization of the manufacturing process of UHT full fat requeijão cremoso (long-life) as well as the development of a process to manufacture reduced fat version of UHT requeijão cremoso (long-life), in a way such as to obtain final products with characteristics similar to those of traditional commercial requeijão cremoso produced with the normal heat treatment. The processed cheeses were all made from fresh curds obtained by direct acidification of heated skim milk. Milk cream, emulsifying salt and sodium chloride were added to the curds before initiating the melting process. In the case of the reduced fat versions, milk fat was partially replaced by a fat substitute (WPC 34). The final products were hot-filled into glass containers (full fat and reduced fat requeijão cremoso) or sterilized by UHT processing (143ºC/3-5 seconds) before being aseptically filled into 125 mL Tetra Pak packages (full fat UHT requeijão cremoso and reduced fat UHT requeijão cremoso). The processed cheeses were evaluated and compared for physical-chemical, microbiological, texture profile analysis (TPA) and sensory (acceptability, DQA, shelf life study) characteristics, protein electrophoretic profile, scanning electron microscopy (SEM) and color (instrumental). No statistically significant (p < 0,05) differences were found in the chemical composition of the requeijão cremoso types investigated (traditional heat and UHT processing). The traditional reduced fat and UHT reduced fat requeijão cremoso presented quite similar chemical compositions. During storage for 90 days at 5ºC, the pH value and lactose levels of the traditional and UHT full fat requeijão cremoso samples did not show any significant differences (p < 0,05). Lipids oxidation as measured by TBA method was found to be significantly higher in the samples of requeijão cremoso (glass containers) compared to UHT requeijão cremoso after 30, 60 and 90 days storage. No statistically significant (p < 0,05) differences were found in the TBA values of the full fat UHT requeijão cremoso (stored at 5 and 25ºC) during the180 days storage period studied, except after the 135 days. In addition to being of satisfactory microbiological quality and in compliance with all applicable standards, the glass-packed requeijão cremoso samples (full fat and reduced fat) did not present any microbiological changes after 90 days storage at 4-5ºC. The results of the incubation test clearly show that the long-life processed cheeses (UHT full fat and UHT reduced fat requeijão cremoso) were also considered microbiologically safe and fit for human consumption as they did not present bacterial growth, change of pH value and visual appearance after incubation at 35-37ºC for 7 days. The texture profile parameter values (firmness, adhesiveness, elasticity and cohesiveness) of the glass-packed full-fat requeijão cremoso samples were significantly (p < 0,05) different from those of the UHT full fat cheeses during 90 days at 5ºC. In general, no significant differences (p < 0,05) were found between texture profile attributes of UHT full fat and UHT reduced fat processed cheeses when stored at 5 and 25ºC. No significant changes in the color parameters values (L*, b*, IB) of the glass-packed full fat and reduced fat requeijão cremoso, and UHT full fat and UHT reduced fat requeijão cremoso were observed throughout 90 days storage at 5C. Also in the case of UHT full fat and UHT reduced fat requeijão samples stored at 5 and 25ºC, the color parameter values did not measurably change during 180 days storage. No statistically significant differences (p < 0,05) were detected as to interaction between the samples (full fat and UHT full fat requeijão cremoso) and the storage period investigated, thus the heat treatment to which the different RC types were exposed during the manufacturing process did not produce any significant differences in terms of pH value, lactose levels, texture profile parameter values and color parameters values during 90 days at 5ºC. No statistically significant differences (p < 0,05) were detected as to interaction between the samples and the storage period investigated relative to the color parameters values and the texture profile parameter values of reduced fat and UHT reduced fat requeijão cremoso. No significant differences (p < 0,05) were found between the samples (stored at 5 and 25ºC) and the storage period, thus, storage temperatures did not significantly affect the TBA values, the color parameters values and the texture profile attributes of UHT full fat requeijão cremoso and UHT reduced fat requeijão cremoso during 180 days at 5 and 25ºC. Images generated by scanning electron microscopy (SEM) showed marked differences between the microstructure of glass-packed full fat and UHT full fat requeijão cremoso on one hand, and between the microstructure of glass-packed reduced fat and UHT reduced fat requeijão cremoso on the other. These differences are probably due to effects of the heat and mechanical treatments inherent to UHT processing. In spite of having similar chemical compositions, the differences in texture and microstructure of the UHT full fat and UHT reduced fat requeijão cremoso versions are desirable and necessary, not only to enable the product to be filled into the package, but also to facilitate its consumption. The electrophoretic profiles of the full fat requeijão cremoso versions (glass-packed and UHT-processed) exhibited fractions of ß-CN, as1-CN e ?-CN. In addition to these fractions, the electrophoretic profile of glass-packed full fat requeijão cremoso shows also the presence of the as1 - I CN fraction. There was no difference between the electrophoretic profiles of the proteins present in the glass-packed reduced fat requeijão cremoso and that of the UHT reduced fat product, both of which contained the ß-CN, as1-CN and ?-CN fractions. No perceptible changes were observed in the electrophoretic profiles of the glass-packed requeijão samples (full fat and reduced fat) during the 90-day storage period studied, nor in the profile of the UHT full fat and UHT reduced fat cheeses during 180 days storage, thereby indicating that none of the four requeijão cremoso types studied was affected by proteolysis or casein fraction breakdown with time. The results of sensory acceptability analysis showed that both the glass-packed and UHT full fat requeijão cremoso samples received a high percentage of good ratings for overall sensory acceptability. The consistency and spreadability attributes of the UHT full fat requeijão cremoso samples received high percentages of rejection compared to the other sample types, with consistency receiving the lowest scores of acceptability. On the other hand, the samples of glass-packed reduced fat requeijão cremoso and UHT reduced fat requeijão cremoso obtained good percentage ratings for overall acceptability and received higher ratings for this attribute as compared to 2 different brands of commercial reduced fat requeijão. As for consistency and spreadability, particularly the samples of glass-packed and UHT reduced fat cheese which obtained consistently higher ratings compared to all the other samples types analysed. As for the attribute taste, UHT reduced fat requeijão cremoso received the highest scores for acceptability. The results of quantitative descriptive analysis show that (5% error level), compared to the glasspacked full fat product, the UHT full fat requeijão cremoso presented a darker tone of creamy white color, less firm and more fluid consistency, smoother and more fluid cheese flow on bread, less mouthfeel & body and a more intense acidic note. These samples exhibited similar intensity of aroma and typical requeijão and milk cream taste, ripened cheese aroma and salty and bitter flavor notes. Compared to the glass-packed reduced fat requeijão, the UHT reduced fat requeijão cremoso samples were found to exhibit only less intense taste of typical requeijão (5% error level). Based on the results of the shelf-life study and considering the need for a safety margin that would guarantee the safety of the product, the following shelf life times are suggested: (1) UHT full fat requeijão cremoso (long-life): 6 months when stored under refrigeration at up to 10º C; 5 months when stored at up to 25º C and 2 months when stored at up to 35º C; (2) UHT reduced fat requeijão cremoso (long-life): 6 months when stored under refrigeration at up to 10º C; 4 months when stored at a temperature of 25º C and 2 months when stored at up to 35º C. The use of UHT processing in the manufacture of requeijão cremoso aims at extending the shelf life of the product as a result of both the higher efficiency of the UHT process as compared to the traditional heat treatment and the advantages of the aseptic package that not only eliminates the need of refrigeration but also facilitates handling throughout the distribution chain. Thus, this new technology provides a new and technically & economically feasible alternative for large-scale dairy plants
Doutorado
Doutor em Tecnologia de Alimentos

The ability of coated particles of enriched uranium dioxide (UO2) fuel to withstand high temperatures and contain the fission products in the case of a loss of cooling event is a vital passive safety measure over traditional nuclear fuel requiring active safety systems to provide cooling. As a possible solution towards enhancing the safety of light-water reactors (LWRs), it is envisaged that the fuel in the form of loose-coated particles in a helium atmosphere can be introduced inside Silicon-Carbide nuclear reactor fuel cladding tubes of the fuel elements. The coated particles in this investigation were treated as a bed from where heat was transferred to the cladding tube by means of helium gas and the gas movement was by natural convection. Hence, it is proposed that light-water reactors (LWR) could be made safer by redesigning the fuel in the fuel assembly (see Fig. 1.3b). As a first step towards the implementation of this proposal, a proper understanding of the mechanisms of heat transfer, fluid flow and pressure drop through a packed bed of spheres during natural convection was of utmost importance. Such an understanding was achieved through a review of existing literature on porous media. However, most heat transfer correlations and models in heated packed beds are for forced convectional conditions and as such characterise porous media as a function of Reynolds number only rather than expressing media heat transfer performance as a function of thermal properties of the bed in combination with the various components of the overall heat transfer. The media heat transfer performance considered as a function of thermal properties of the bed in the proposed design is found to be a more appropriate approach than the media as a function of Reynolds number. The quest to examine the particle-to-fluid heat transfer characteristics expected in the proposed new fuel design led to implementing this research work in three phases, namely experimental, theoretical and numerical simulation. An experimental investigation of fluid-to-particle natural convection heat transfer characteristics in packed beds heated from below was carried out. Captured data readings from the experiment were analysed and heat transfer characteristics in the medium evaluated by applying the first principle heat transfer concept. A basic unit cell (BUC) model was developed for the theoretical analysis and applied to determine the heat transfer coefficient, h, of the medium. The model adopted a concept in which a single unit of the packed bed was analysed and taken as representative of the entire bed; it related the convective heat transfer effect of the flowing fluid with the conduction and radiative effect at the finite contact spot between adjacent unit cell particles. As a result, the model could account for the thermophysical properties of sphere particles and the heated gas, the interstitial gas effect, gas temperature, contact interface between particles, particle size and particle temperature distribution in the investigated medium. Although the heat transfer phenomenon experienced in the experimental set-up was a reverse case of the proposed fuel design, the study with the achievement in the validation with the Gunn correlation aided in developing the appropriate theoretical relations required for evaluating the heat transfer characteristics in the proposed nuclear fuel design. A slender geometrical model mimicking the proposed nuclear fuel in the cladding was numerically simulated to investigate the heat transfer characteristics and flow distribution under the natural convective conditions anticipated in beds of randomly packed spheres (coated fuel particles) using a commercial code. Random packing of the particles was achieved by discrete element method (DEM) simulation with the aid of Star CCM+ while particle-to-particle and particle-to-wall contacts were achieved through the combined use of the commercial code and a SolidWorks CAD package. Surface-to-surface radiative heat transfer was modelled in the simulation reflecting real-life application. The numerical results obtained allowed for the determination of parameters such as particle-to-fluid heat transfer coefficient, Nusselt number, Grashof number and Rayleigh number. These parameters were of prime importance when analysing the heat transfer performance of a fixed bed reactor. A comparison of three approaches indicated that the application of the CFD combined with the BUC model gave a better expression of the heat transfer phenomenon in the medium mimicking the heat transfer in the new fuel design
Thesis (PhD)--University of Pretoria, 2016.
Mechanical and Aeronautical Engineering
PhD
Unrestricted

Two experiments have been conducted to ascertain if a cell with a palladium cathode, a platinum anode, and a solution of H2SO4 in D2O can produce excess heat under electrolysis compared to a similar cell with H2O. In each experiment, two cells were connected in series with constant current. The two cells were identical except for the fact that the heavy water cell used D2O instead of H2O in the electrolyte. Both cells in each experiment employed Pd cathodes, Pt anodes, and H2SO4 in the solution. On a piece of Pd foil that had been cold-rolled and cleaned like the cathodes but had not been electrolyzed, scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) failed to find any traces of unexpected elements. In the first experiment the indication was that the light water cell was slightly warmer despite receiving slightly less power. Small amounts of silver were found on both cathodes after electrolysis. In the second experiment, the D2O cell produced an excess heat relative to the H2O cell that was too large by at least an order of magnitude to be explainable by chemical reactions or mechanical artifacts. After electrolysis, it was found that Cd was present on the surface of the H2O cathode at levels of concentration that were variable but generally no less than 4% relative to Pd (above 3σ). The H2O cathode of this second experiment finished electrolysis very straight. The D2O cell cathode finished severely arched (~30o), with its convex side facing the anode, and covered in a deposit of powdery black substance which was most likely PdS formed accidentally on the first day of this experiment when the D2O cell had been run with the wrong polarity. On this D2O cell cathode, no statistically significant traces of Cd were detected but Ag was present in 2-5% concentration relative to Pd. In some spots, the Ag abundance surpassed 20% that of Pd. The most likely explanation is neutron-induced nuclear transmutation of some of the Pd nuclides with direct release of heat into the solid-state lattice.

This study explores the reactions and related species of NOx pollutants in methane flames in order to understand their production and consumption during the combustion process. To do this, several analytical simulations were run to explore the behavior of nitrogen species in the pre-flame, post- flame, and reaction layer regions. The results were then analyzed in order to identify all "steady-state" species in the flame as well as the determine all the unnecessary reactions and species that are not required to meet a defined accuracy. The reductions were then applied and proven to be viable.

Solar energy is incident on the earth's surface in both short-wave and long-wave parts of the spectrum. The short-wave part of the spectrum is of special interest to oceanographers since the vertical distribution of temperature in the top layer of the ocean is mostly determined by the vertical attenuation of short-wave radiation. There are numerous studies regarding the temperature evolution as a function of time (see Chapter 2 for details). The diurnal and seasonal variation of the heat content (and hence temperature) of the ocean is explored in this thesis. The basis for such heat budget simulation lies in the fact that the heat budget is the primary driver of ocean currents (maybe secondary to wind effects) and these circulation features affect the biological and chemical effects of that region. The vertical attenuation of light (classified to be in the 300-700 nm range) in the top layer of the ocean has been parameterized by several authors. Simpson and Dickey (1981) in their paper have listed the various attenuation schemes in use till then. This includes a single-exponential form, a bimodal exponential form, and a spectral decomposition into nine spectral bands, each with their specific exponential functions with depth. The effects of vertical light attenuation have been investigated by integrating the light models into a 1D and a 3D turbulence closure model. The main part of the thesis is the inclusion of a bottom effect in the shallow waters. Bottom serves two purposes, it reflects some light based on its albedo and it radiates the rest of the light as heat. 1-D simulation including bottom effects clearly indicates the effect of light on the temperature profile and also the corresponding effect on salinity profiles. An extension of the study includes a 3D simulation of the heat budget and the associated circulation and hydrodynamics. Intense heating due to the bottom leads to the formation of hyper-saline waters that percolate down to depths of 50 m in the summer. Such plumes have been simulated by using a 3D numerical ocean model and it is consistent with observations from the Bahamas banks.

碩士
國立臺北科技大學
製造科技研究所
99
This thesis maimly aim at developing the medical diagnosis lamp with LED, In consideration to the lighting in the use of heat that will reduce the thermal resistance to the design of the whole system to achieve effective heat dissipation, we use the system identification to find the transfer function for simulating the safe operating temperature when developing,the transfer function have a total of the number 4-order pole and 3- order zeros that are considering, then simulating the LED crystal core, metal, circuit boards ,the junction temperature and the thermal resistance,temperature can be controlled by each chip operating at safe temperatures.The simulate error is within 1%,the Max. temperature is 1.7℃,the relative error temperature is 0.01℃, relative error percent is 0.62%,after the security temperature will be obtained in accordance.The Tb simulated temperature distribution at between 45 ℃ ~ 76 ℃, and the experimental error of less than 0.8%, and then simulate the distribution curve of Tj Between 62.5 ℃ ~ 94.3 ℃ to 100 ℃, it indicated this analog of copper cooling, heat sink and fan links will make this lamp to achieve a good cooling effect.

碩士
國立臺灣科技大學
電子工程系
98
In this thesis, we focus on the subject of improvement of luminosity efficiency and cooling ability of heat dissipation for white light LEDs lamp. The purpose is to replace the conventional lamp. At beginning, we focus on the researches to achieve high luminosity efficiency of commercial white light LED. The study leads us to propose a concept of making a light bulb by a 3×3 LED array. A prototype is made. A serious measurement is performed to validate the concept. At present, the efficiency is about 60 to 70 lumens per watt for the commercial white light LED lamp with luminosity more than 600 lumens. For our 3 × 3 LED array bulb it can produce luminosity as high as 800 lumens. This new model can achieve light efficiency about 85 lumens per watt with the optimized input power. As regard to the heat issues, the common way to dissipate heat is heat-sink-fin, however we put the heat issues in a more comprehensive concept of systematic management of the hot spot. Not only we avoid the light bulb model producing high heat density, but also we use a similar concept of heat pipe to use non-conductive deionized water in a sealed space to contact white light LED hot spot. It rapidly takes away the heat from LED, enabling the white LED to continuously work on allowed temperature range, achieving a more perfect result and increasing the lamp lifetime. From the curve of efficiency, we compare the results of LED lamp with and without cooling mechanism and reach the conclusion that the lamp with cooling mechanism can maintain the efficiency of 80 lumens per watt and the lamp without cooling mechanism reduces to 70 lumens per watt after powered on 30 minutes. We verify that we can make a high power and high efficiency LED lamp to replace the commercial fluorescent lamp.

The Oregon State University (OSU) Radiation Center (RC) is the location of a one quarter scale model of the Westinghouse Electric Corporation advanced light-water nuclear reactor design called the AP-600. The full scale AP-600 is a 600 megawatt electric nuclear power plant that incorporates unique passive systems to perform the safety functions currently required of all existing nuclear power plants. Passive safety refers to a system's ability to perform its desired function using natural forces such as gravity and natural circulation. This reduces the reliance on active systems to assure plant safety. The Advanced Plant Experiment (APEX) at the OSU RC is an electrically heated simulation of the AP-600 that includes the Nuclear Steam Supply System (NSSS) and all of the passive safety systems. The APEX facility was funded by the United States Department of Energy and the Westinghouse Electric Corporation. The facility was built to perform the long term cooling tests necessary for design certification of the AP-600. The data taken will be used to benchmark the thermal hydraulic computer codes applied in the design certification process and to better understand the phenomena involved in the full scale AP-600. This paper presents the analysis of the Passive Residual Heat Removal System (PRHR) and in particular the PRHR's "c"-shaped heat exchanger (PRHR Hx). This paper includes analysis and modeling of the PRHR Hx including: hydraulic flow parameters, heat rejection capability, an empirical correlation for determining pressure drop, and an examination of the flow phenomena that occurs in the tank in which the heat exchanger is installed.
Graduation date: 1997

碩士
國立中興大學
精密工程學系所
96
The purpose of this study was to discuss the heat dissipation methods for light emitting diode. There are two major parts in the study: (1) Improving LED packaging materials. The behavior of having low thermal resistance and high thermal diffusion efficiency are evaluated by coating a copper material on LED base layer. We calculate the heat transfer simulation using 3-D finite element method. The simulation results of various packaging area parameters were presented. (2) To design heat pipe structures as heat sink for a interior LED illuminator set. The experiments were conducted to investigate the cooling characteristics of heat pipes by changing working fluid mass and working angle. Additionally, both discrete hotspot of LED and central heating of heat pipe were studied. From the first simulation result, it was found that the addition of 9cm2 copper-packaged area improves the thermal dissipation of LED, resulting in a reduction of chip temperature lower 5℃ than non-packaging pattern. Secondly, the results of heat pipe experiments show that when the experimental sets of LED illuminator of LED was used in horizontal angles, resulting in the heat pipe which fill 2.52g water volume have the best thermal properties than others. Resulting in the heat source temperature maintain in 50℃. Whereas other have higher temperature results due to the steam inside pipe choked. Next, when the LED illuminator sets was used in inclined angles, the heat pipe which fill 7.56g water volume have the best thermal properties than others. The heat source temperature can reach 60℃. All of the experiments were performed and the results were presented. The experiments results show in this study can therefore be used for the application of heat dissipation for LED.

碩士
國立中興大學
精密工程學系所
101
As the slimming trend in FPD (flat panel display), the developmental concept about back light Unite (BLU) has been changed from direct type to edge type. Although the amount of LED has decreased gradually, it’s necessary to apply higher power LED than before. Due to the centralized heat originating from LED and limited conduction space, the serious heat problem can’t be solved by nature convection. The second problem brought by thermal is decay about luminance and life time of LED. In this article, we try to analyze heat distribution within BLU by software ANSYS and measure the reality by thermal sensors. In order to check the root cause, the simulation result should be confirmed with experience data. After reviewing the rationality of experience data, we try to find to the best solution about heat problem by Taguchi method. In our conclusion, the best solution against the heat problem is based on the limited space And cost and has been published. It is true that thermal could be under control in the edge type LED back light module.

碩士
國立交通大學
工學院精密與自動化工程學程
101
Light Emitting Diode is called LED. Not only transforming electricity into light directly and efficiently, it also can be used most up to 10 to 100 thousands hours. Unlike traditional fragile bulb, LED is stronger and more power saving. It possesses environmental, no mercury and small volume, and LED also can be applied in low temperature environment. Directional light, low light pollution and rich color gamut are all the benefits of LED. As traditional light, LED produces heat when working, and the heat depends on lighting efficiency. Heat sinking becomes the main problem for LED. Improper heat distributing leads life and light decay. We will discuss the relationship between the most economical heat sink device and its thermal power, when the shape of lamps is limited and in free convection. It takes LED A55 as a sample in this research. This report will simulate different heat sink devices by physical value. It is expected to find the best device which is conforming to low cost for the market.

碩士
中原大學
室內設計研究所
97
ABSTRACT Illuminance, room temperature, and correlated color temperature are essential parameters of every interior lit space. They vary a lot. However, their variations correspond to users’ visual perception, preferences and degrees of comfort. To quest into such preferences and perceptions by concentrating on these parameters, this study ruled out possible distractions from such concerns as walls’ luminance, room colors, and design styles, and constructed a full scale test lab simulating office space. In which, 6 sets of 4 by 14 Watt T5 fluorescent tubes are assembled on an aluminum ceiling frame. Operated concurrently with 3 levels of room temperature and 2 kinds of color light, this ceiling which is chained on the building structure to ascend and descend provides uniformly distributed down lighting in 3 different illuminces to house 4 subjects who filled out semantic differential questionnaires. Through such a design, this study learned that subjects prefer 3000K color light to 7000K’s under all sorts of semantic terms. Although it is important that office attendants keep vital and concentrated, the subjects take to the yellowish lit ambiance beyond the concern of where and when one is located. In addition, lower room temperature (20℃) and lower illuminance (200 lux) cause negative responses to lit environment, while higher room temperature (28℃) is tolerable to subjects in most occasions. Keywords: lighting, luminaire, correlated color temperature, room temperature, visual perception

碩士
華梵大學
機電工程學系博碩專班
101
Abstract LED is energy-saving, eco-friendly, sustainable, and with advantages such as lower CO2 emission etc. It is slowly replacing traditional fluorescent bulbs in brightness and illumination. However, one of the key obstacles to overcome is its heat dissipation problem. The purpose of this dissertation is to investigate the temperature and flow fields of LED light bulbs. A commercial LED light bulb, with model number of XH-SBPar30-7 * 1W, is used as the base model. A couple of modified models with different numbers of fin are also studied. A computational fluid dynamics software, ANSYS Fluent, is utilized to simulate and analyze heat dissipation performance. Free and forced convections are both conducted. The air velocity and temperature distributions are solved according to mass, momentum, and energy conservation equations for the fluid domain while the temperature field of the LED light bulb itself is calculated through conjugate heat transfer. The cooling performance under free and forced convections with 3, 4, and 5 fin models are compared. It is observed that the heat dissipation performance is better with forced convection. The heat transfer effects are better when the air velocity is higher. The performance varies with wind speed, fin number, thickness and airspaces of the fins in each convection case. For the natural convection case, 5-fin model has the highest temperature; while the 3-fin model has the lowest temperature. When air velocity is 0.2 m/s, the temperature of 5-fin model still is the highest. However, the temperature of 3-fin model is approaching that of model the 4-fin. When the air velocity reaches 0.4 m/s, the temperature of 3-fin model becomes higher than the 4-fin model’s temperature. Keywords: LED, thermal analysis, computational fluid dynamics

This thesis is dedicated to certain nonlocal aspects of conformal quantum field theories (CFTs). Two main directions are the study of CFTs on a particular globally-nontrivial spacetime corresponding to finite temperature, and the study of particular nonlocal CFT observables localized on light-rays. Specifically, we introduce bootstrap techniques for determining finite-temperature data of CFTs, and make novel predictions for the 2+1-dimensional Ising model. We propose the “stringy equivalence principle”, stating that coincident gravitational shocks commute, as a generalization of the strong equivalence principle of Einstein’s General Relativity that must hold in all consistent theories of gravity. We prove it in Anti-de Sitter (AdS) spacetimes by studying light-ray operators in the holographically dual CFT. We also derive an operator product expansion (OPE) for light-ray operators in CFT, by which two light-ray operators on the same light-sheet can be expanded as a sum of single light-ray operators. Light-ray operators model detectors — such as calorimeters. We use the light-ray OPE to compute energy event shape observables suitable for conformal collider physics.

An additional part of this thesis determines the low-energy vacua of two-dimensional maximal super-Yang-Mills theory, which describes the dynamics of stacks of D-strings in Type IIB string theory. By computing an invariant of the renormalization group (RG) flow from high to low energy — a modified thermal partition function named the refined elliptic genus — we prove the existence of multiple vacua, and identify the superconformal field theories capturing their dynamics. The vacua correspond to bound states of (p,q)-strings in Type IIB string theory. Our computation serves as a check of the strong-weak S-duality of the Type IIB string.

碩士
國立臺南大學
綠色能源學科技學系碩士在職專班
103
As the semiconductor industry consist a wide range of process, waste heat generated, acid, alkaline and organic solvents gas in the production process must be uninterrupted use of the exhaust system pumping. Most of require exhaust pollution control equipment after handling air emissions to the atmosphere, in order to maintain the normal operation of the machine as well as environmental and worker safety. Among them, the semiconductor industry in the light-emitting diode (LED), epitaxial production of major equipment for Metal Organic Chemical Vapor Deposition (MOCVD). The general characteristics of the exhaust but no harm have winds of gas composition. Because of MOCVD production need to have the level of cleanliness of no more than 105 in a size range of 0.5μm and larger operating environment. Therefore MOCVD exhaust required by the air conditioning system of the outdoor air (OA) after processing, then add to the cleanroom. OA need to go through several channels of filter in order to achieve particle control purposes, and humidification, dehumidification and temperature control program reaches the production area to maintain constant temperature and humidity, so a lot of exhaust also equivalent to consume a lot of air conditioning energy consumption. Therefore, this study to a manufacturing LED epitaxy facility planned general exhaust emissions to replace part of the MOCVD OA recycling reuse as discussed. Although the recovery of the exhaust sound energy savings can be achieved, but in MOCVD epitaxial process required to use the large amounts of hydrogen and ammonia gas leak occurred even if the fires will endanger the safety of operations. Therefore, this study energy-recovery system planning as a priority consideration to the safety of personnel, and to build the system verify the actual energy efficiency.

Light and temperature are two of the most important environmental factors regulating plant development. Although heat stress has been well studied, little is known about the interaction between light and temperature. In this study, we performed phenotypic assays comparing seedling responses to heat under light and dark conditions. Seedlings exposed to heat in the dark show lower survival rates than seedlings stressed in the light. To identify transcriptional changes underlying light-dependent heat tolerance, we used RNA-sequencing. The light-dependent heat stress responses involved a plethora of genes which could be potential candidate genes for light-induced heat tolerance, including transcription factors (bHLH) and genes commonly associated with biotic stress. By using the latest high-throughput phenotyping facility, we found that the light-dependent heat tolerance is reflected more on the maintenance of photosynthetic capacity, rather than leaf temperature. These results provide insights into how light increases heat stress tolerance in Arabidopsis seedlings and suggest its underlying mechanisms.

碩士
國立雲林科技大學
機械工程系碩士班
92
For constructing to draw up in the space the ecosystem environment of the earth''s surface, don''t only need the food and aquas, more important provide a light energy source. Is the environment of a several near whole seals in too overgead hatch, however the energy lasting retrieval energy is the radiation energy of the outer space. Radiating can not can only to convert energy, can also provide the light source, heat energy. Through experiment, the availability completes the temperature isetrol and light source strengths regulate and then can provide the living creature existence of the source of power. Adopting the low thermal resistance material makes case then with certain grow the openings unit design to let ray of light entered to shoot through the permease or the diffusion method enters, this fraction the proportion plants the sheeting outlying area of planting the tower composition, including the illumination and entering the wind rose, aqua to plant, the plant basin an iso - will be a main design study space region. And most the case design then need to be considered and can bear the material of the very low thermal resistance in small aerolite collision in space at the same time. The adoption bears the autovac of the environment of racuum, duct into the infrared, laser, sun lighting and purple and outside lights.Difference with special flip light flake filtration heat source and purple and outside light, also then equip the cooling, heating apparatus exit in the ray of light with measurement of lumen meter or CDS，the thermocouple，and UV sensor of its effect of surroundings and change

碩士
國立彰化師範大學
電機工程學系
101
Abstract Owing to the junction temperature of an LED light source affecting its lifespan, thus both natural and forced heat dissipation methods are employed in this research with five different heat sinks to investigate the heat dissipation effect and to calculate the actual benefit of the heat sinks in the embedded LED lamp. Firstly, the temperature of the embedded LED lamp was measured to estimate its lifespan, and then its cost per hour was calculated through its acquisition cost. Then, under the same conditions, five kinds of heat sinks, including a fin heat sink, a heat pipe, a heat pipe plus a fan heat sink, a fin plus a fan heat sink, and a cooling chip, were attached to the lamps, respectively. The changes in temperature and power consumption of the lamps helped estimate the benefit of heat sinks in expanding lifespan of LED lamps. After deducting the acquisition cost of each heat sink and the operational power cost, the researcher found that heat dissipation by using a fin plus a fan heat sink obtains the best economical benefit among these five kinds of heat sinks and the LED lifespan is doubled. Furthermore, a cost of 764 NT dollars can be saved after the deduction of their acquisition cost and operational cost. The amount which the heat sink saves reaches 127% of its acquisition cost. Meanwhile, the order of benefit priority of the other heat sinks is the fin heat sink, the heat pipe plus a fan heat sink, the heat pipe, and the cooling chip. Though the lifespan of LED lamps equipped with a cooling chip can be expanded, addition of a cooling chip costs 3,800NT dollars more even its benefit of expanding lifespan is subtracted. In addition, this method needs more run cost, which turns out to be far from economical. Keywords: LED lighting, heat sink, fin heat sink, heat pipe, cooling chip

碩士
長庚大學
電子工程研究所
95
There are two widely methods to measure junction temperature. They are diode forward-voltage method and emission peak wavelength. These two ways can find out why temperature goes up, but it may produce difference in other device. This study uses Fourier’s Law to improve measuring junction temperature. We assume a boundary condition into differential function and get a solution of diffusions in temperature. The solution can clearly describe dynamic behavior in LED. We use forward-voltage method to measure operating voltage of LED. In our circuit, we give the LED device different current by changing it from high to low or low to high. At the result, we obtain the thermal conductivity of GaAs and it is only 16% less that in the literature. The result also proves the heat in LED coming from p-n junction and substrate. The temperature is almost the same as peak wavelength.

碩士
長庚大學
電子工程學系
99
Light emitting diodes (LED) with low power consumption, long life time, small size and fast response are going to be the mainstream device in the solid-state lighting applications. When LED used as lighting devices, it has to exhibit high-power operation to achieve the required brightness. At the meanwhile, how to dissipate heat generated from LED is a very important issue for the real applications. In this thesis, gold bump which have high thermal conductivity (291 W/m-K), and silicon sub-mount had been adopted to achieve Flip-Chip LEDs fabrication. Since Flip-Chip LED can dissipate heat through gold bumps and silicon sub-mount, the light output efficiency will be enhanced. Nowaday, LED solid state lighting products available today use well known PCB sub-mount.. In this work, finite-element model (FRM) numerical simulation had been used to find the heat dissipation capability of silicon sub-mount and PCB sub-mount models (which are used Ag-epoxy to fix conventional LED and vertical LED on different sub-mount). It is proven that the heat dissipation capability of silicon sub-mount is superior to PCB sub-mount models. This study also explored the heat dissipation characteristics between flip-chip bonding and Ag adhesive bonding for LED array fabrication, and increase the number of flip-chip LEDs’ bumps to analyze Heat dissipation and output light characteristics.

碩士
國立虎尾科技大學
光電與材料科技研究所
100
As electronic products constantly renovate, the appearance of the products trends to be light, thin, short, as well as small and their functions also direct to high applications, high communication, and high efficiencies. Therefore, the technology for thermal management in the whole process of product design is persistently important. For the applications of specific products, the pivotal step for device integration of thermal management design is the selection of optimal thermal interface material, promoting the heat-dissipating efficiencies of whole electronic products. In this study, reactive functional hybrid polymers with low contraction, high thermal dissipation, and high adhesion have been prepared by molecular structure design/modification of functional resins, prescription of initiators, and addition/modification of heat-dissipating powders. With the technology for functional prescription design, dispersion, and manipulation of curing speed, furthermore, we have also successfully manufactured thermal dissipating paints with surface resistance 1×109Ω/□~1010Ω/□, thermal conduction constant 11.36W/m.K, adhesion strength 19.45 kgf/cm2, and contraction rate 1.71％, establishing the self-research capabilities of key materials with high added value for domestic optoelectronic/electronic industries and enhancing the competitiveness for international markets.