Littérature scientifique sur le sujet « Conversione calore »
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Articles de revues sur le sujet "Conversione calore"
1
Logan, Trevon D. « The Transformation of Hunger Revisited : Reply ». Journal of Economic History 75, no 2 (juin 2015) : 526–30. http://dx.doi.org/10.1017/s0022050715000704.
Texte intégralRésumé :
The higher calorie levels reported in Gazeley, Newell, Bezabith (2015) are a function of a conversion of food quantities to calories that is weighted towards contemporary, calorie-rich foods. Their conversion uses the full distribution of contemporary foods and should not be applied to historical populations. Since Gazeley, Newell, Bezabith assume that industrial workers in the past had access to contemporary foods, the revised calorie levels reflect contemporary diets rather than historical diets.
2
Claro, Rafael Moreira, Renata Bertazzi Levy, Daniel Henrique Bandoni et Lenise Mondini. « Per capita versus adult-equivalent estimates of calorie availability in household budget surveys ». Cadernos de Saúde Pública 26, no 11 (novembre 2010) : 2188–95. http://dx.doi.org/10.1590/s0102-311x2010001100020.
Texte intégralRésumé :
This study aims to estimate an adult-equivalent scale for calorie requirements and to determine the differences between adult-equivalent and per capita measurements of calorie availability in the Brazilian population. The study used data from the 2002-2003 Brazilian Household Budget Survey. The calorie requirement for a reference adult individual was based on the mean requirements for adult males and females (2,550kcal/day). The conversion factors were defined as the ratios between the calorie requirements for each age group and gender and that of the reference adult. The adult-equivalent calorie availability levels were higher than the per capita levels, with the largest differences in rural and low-income households. Differences in household calorie availability varied from 22kcal/day (households with adults and an adolescent) to 428kcal/day (households with elderly individuals), thus showing that per capital measurements can underestimate the real calorie availability, since they overlook differences in household composition.
3
Wisniak, Jaime. « William John Macquorn Rankine. Thermodynamics, heat conversion, and fluid mechanics ». Educación Química 18, no 3 (22 août 2018) : 238. http://dx.doi.org/10.22201/fq.18708404e.2007.3.65955.
Texte intégralRésumé :
<span>William John Macquorn Rankine (1820-1870) fue un científico, educador e ingeniero muy prolífico y multifuncional, un pionero en el esfuerzo de llevar los recursos de las matemáticas y la física a los problemas prácticos de la ciencia y la ingeniería. Sus contribuciones abarcan un amplio intervalo de actividades: termodinámica, conversión del calor, mecánica de fluidos, construcción de barcos, mecánica de los sólidos y de los suelos, así como temas filosóficos. Él es particularmente famoso por sus contribuciones a la termodinámica, al entendimiento de las máquinas térmicas y al desarrollo de la segunda ley. Entre sus contribuciones en esta área tenemos la escala Rankine de temperaturas y el ciclo de vapor Rankine para la conversión de calor en trabajo. Fue el primero que definió tensión y esfuerzo rigurosamente.</span>
4
Obando-Perea, Jairo V., Carlos M. Montaño-Torres, Rita D. Caicedo-Zambrano, María C. Santos-Falcónez, Nixon E. Proaño-Bone et Edinson E. Castro-Uriarte. « Utilización efectiva del enfriador de catalizador ». Polo del Conocimiento 2, no 12 (12 mars 2018) : 87. http://dx.doi.org/10.23857/pc.v2i12.413.
Texte intégralRésumé :
<p style="text-align: justify;">El equipo enfriador de catalizador, es un intercambiador de calor basado en la utilización de agua fresca, que además de enfriar el catalizador regenerado, debido a la combustión del coque que se produce por la conversión de la carga en el reactor, generará vapor de presión media. El crudo reducido generará una mayor cantidad de residuo de carbón en el regenerador, y que por ende al ser combustionado la cantidad de calor liberado será mayor. El objetivo de este trabajo es determinar la cantidad de calor que se liberará según la variación del % en peso de crudo reducido y gasóleo, y calcular la cantidad de agua que se producirá en el <em>Catalyst Cooler</em> al mantener el sistema Reactor-Regenerador a temperatura óptima de operación. Para ello se revisa la literatura, se determinan ecuaciones de transferencia de calor y se detallan los equipos. Se realizan los cálculos sobre la cantidad de coque que se producirá en función de la variación del porcentaje en peso de gasóleo y crudo reducido, además de calcular la cantidad de calor que se generará al combustionar el coque que está adherido al catalizador y que ingresará al regenerador para ser descoquizado y ser recirculado hacia el reactor para un nuevo proceso de conversión. Esto aprovecha energía térmica que antes se desperdiciaba provocando impactos ambientales y pérdidas económicas.</p>
5
Boucher, Joshua M., Larisa Ryzhova, Anne Harrington, Jessica Davis-Knowlton, Jacqueline E. Turner, Emily Cooper, David Maridas et al. « Pathological Conversion of Mouse Perivascular Adipose Tissue by Notch Activation ». Arteriosclerosis, Thrombosis, and Vascular Biology 40, no 9 (septembre 2020) : 2227–43. http://dx.doi.org/10.1161/atvbaha.120.314731.
Texte intégralRésumé :
Objective: Perivascular adipose tissue (PVAT) surrounding arteries supports healthy vascular function. During obesity, PVAT loses its vasoprotective effect. We study pathological conversion of PVAT, which involves molecular changes in protein profiles and functional changes in adipocytes. Approach and Results: C57BL6/J mice were fed a 60% high-fat diet for 12 weeks or a cardioprotective 30% calorie-restricted diet for 5 weeks. Proteomic analysis identified PVAT as a molecularly distinct adipose depot, and novel markers for thermogenic adipocytes, such as GRP75 (stress-70 protein, mitochondrial), were identified. High-fat diet increased the similarity of protein signatures in PVAT and brown adipose, suggesting activation of a conserved whitening pathway. The whitening phenotype was characterized by suppression of UCP1 (uncoupling protein 1) and increased lipid deposition, leptin, and inflammation, and specifically in PVAT, elevated Notch signaling. Conversely, PVAT from calorie-restricted mice had decreased Notch signaling and less lipid. Using the Adipoq-Cre strain, we constitutively activated Notch1 signaling in adipocytes, which phenocopied the changes in PVAT caused by a high-fat diet, even on a standard diet. Preadipocytes from mouse PVAT expressed Sca1, CD140a, Notch1, and Notch2, but not CD105, showing differences compared with preadipocytes from other depots. Inhibition of Notch signaling during differentiation of PVAT-derived preadipocytes reduced lipid deposition and adipocyte marker expression. Conclusions: PVAT shares features with other adipose depots, but has a unique protein signature that is regulated by dietary stress. Increased Notch signaling in PVAT is sufficient to initiate the pathological conversion of PVAT by promoting adipogenesis and lipid accumulation and may thus prime the microenvironment for vascular disease.
6
Silva, Thiago Rodrigues da, Karina Márcia Ribeiro de Souza Nascimento, Charles Kiefer, Luanna Lopes Paiva Copat, Henrique Barbosa de Freitas, Natália Ramos Batista Chaves, Larissa Albuquerque Rosa Silva, Jeovania Vilhalba Leite et Arnaldo Vitorino Ofiço. « Metabolizable energy levels in diets with a fixed nutrient : calorie ratio for free-range broilers ». Semina : Ciências Agrárias 42, no 6supl2 (8 octobre 2021) : 4009–22. http://dx.doi.org/10.5433/1679-0359.2021v42n6supl2p4009.
Texte intégralRésumé :
The present study proposes to examine the effect of dietary levels of metabolizable energy, under a fixed nutrient:calorie ratio, on the production performance; body fat and protein deposition; and carcass characteristics of free-range broilers from 1 to 84 days of age. Nine hundred unsexed chicks were allocated to six treatments in a completely randomized design with six replicates of 25 birds each. Treatments consisted of diets with varying levels of metabolizable energy (2700, 2800, 2900, 3000, 3100 and 3200 Kcal ME/kg of diet) and a fixed proportion of nutrients relative to the energy level according to the nutritional requirements for each rearing phase. Body weight, weight gain, feed intake, feed conversion, production viability, metabolizable energy intake, protein intake, lysine intake, body fat deposition, body protein deposition and carcass characteristics were evaluated. Data were subjected to analysis of variance and, later, to regression analysis. Increasing levels of metabolizable energy, coupled with a fixed nutrient:calorie ratio, reduced feed intake, increased body weight and weight gain, improved feed conversion and did not affect carcass characteristics. In conclusion, adjusting the nutrient supply according to the dietary energy level improves production performance by improving feed conversion, ensuring adequate nutrient intake and preserving fat and protein deposition in the carcass when the metabolizable energy level is raised up to 3200 Kcal/kg in all rearing stages.
7
Ladero, Victor, Ana Ramos, Anne Wiersma, Philippe Goffin, André Schanck, Michiel Kleerebezem, Jeroen Hugenholtz, Eddy J. Smid et Pascal Hols. « High-Level Production of the Low-Calorie Sugar Sorbitol by Lactobacillus plantarum through Metabolic Engineering ». Applied and Environmental Microbiology 73, no 6 (19 janvier 2007) : 1864–72. http://dx.doi.org/10.1128/aem.02304-06.
Texte intégralRésumé :
ABSTRACT Sorbitol is a low-calorie sugar alcohol that is largely used as an ingredient in the food industry, based on its sweetness and its high solubility. Here, we investigated the capacity of Lactobacillus plantarum, a lactic acid bacterium found in many fermented food products and in the gastrointestinal tract of mammals, to produce sorbitol from fructose-6-phosphate by reverting the sorbitol catabolic pathway in a mutant strain deficient for both l- and d-lactate dehydrogenase activities. The two sorbitol-6-phosphate dehydrogenase (Stl6PDH) genes (srlD1 and srlD2) identified in the genome sequence were constitutively expressed at a high level in this mutant strain. Both Stl6PDH enzymes were shown to be active, and high specific activity could be detected in the overexpressing strains. Using resting cells under pH control with glucose as a substrate, both Stl6PDHs were capable of rerouting the glycolytic flux from fructose-6-phosphate toward sorbitol production with a remarkably high efficiency (61 to 65% glucose conversion), which is close to the maximal theoretical value of 67%. Mannitol production was also detected, albeit at a lower level than the control strain (9 to 13% glucose conversion), indicating competition for fructose-6-phosphate rerouting by natively expressed mannitol-1-phosphate dehydrogenase. By analogy, low levels of this enzyme were detected in both the wild-type and the lactate dehydrogenase-deficient strain backgrounds. After optimization, 25% of sugar conversion into sorbitol was achieved with cells grown under pH control. The role of intracellular NADH pools in the determination of the maximal sorbitol production is discussed.
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Atsbha, Tesfalem Aregawi, Taeksang Yoon, Byung-Hoon Yoo et Chul-Jin Lee. « Techno-Economic and Environmental Analysis for Direct Catalytic Conversion of CO2 to Methanol and Liquid/High-Calorie-SNG Fuels ». Catalysts 11, no 6 (29 mai 2021) : 687. http://dx.doi.org/10.3390/catal11060687.
Texte intégralRésumé :
Catalytic hydrogenation of CO2 has great potential to significantly reduce CO2 and contribute to green economy by converting CO2 into a variety of useful products. The goal of this study is to assess and compare the techno-economic and environmental measures of CO2 catalytic conversion to methanol and Fischer–Tropsch-based fuels. More specifically, two separate process models were developed using a process modeler: direct catalytic conversion of CO2 to Fischer–Tropsch-based liquid fuel/high-calorie SNG and direct catalytic conversion of CO2 to methanol. The unit production cost for each process was analyzed and compared to conventional liquid fuel and methanol production processes. CO2 emissions for each process were assessed in terms of global warming potential. The cost and environmental analyses results of each process were used to compare and contrast both routes in terms of economic feasibility and environmental friendliness. The results of both the processes indicated that the total CO2 emissions were significantly reduced compared with their respective conventional processes.
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Pareja Arcila, Juan Carlos, Ilda de Fatima Ferreira Tinoco, Jairo Alexander Osorio Saraz, Keller Sullivan Oliveira Rocha et Márcia Gabrielle Lima Candido. « Zootechnical and physiological performance of broilers in the final stage of growth subjected to different levels of heat stress ». Revista Facultad Nacional de Agronomía 71, no 2 (1 mai 2018) : 8469–76. http://dx.doi.org/10.15446/rfna.v71n2.71927.
Texte intégralRésumé :
El objetivo de este trabajo fue estudiar la influencia de diferentes niveles de estrés térmico del ambiente, incluyendo niveles de confort (25 °C), estrés por calor (28 °C), calor moderado (31 °C), calor alto (34 °C) y calor severo (37 °C), en el desempeño de pollos de engorde en el la última fase de crecimiento (22-42 días), alojados en cámaras climáticas. Se determinaron los parámetros fisiológicos y de comportamiento de los pollos (ganancia de peso (WG), ganancia de peso diaria (DWG), consumo de alimento (FI), índice de conversión alimenticia (FC), mortalidad (MORT), porcentaje de carcasa con relación a la edad y peso corporal (BW), carcasa (CAR), pecho (Bre), muslos (Drum), alas (Win)), de acuerdo a los rangos específicos de temperatura; y se calculó el Índice de Temperatura de Globo Negro y Humedad (ITGH), para el control y evaluación térmica de los tratamientos. En general, las aves mantenidas en temperatura entre 25-28 °C, durante las tres últimas semanas de vida, se comportaron mejor que las expuestas a otras situaciones, e indicando que esta podría ser la temperatura ambiente deseada para las aves en su fase final, en comparación con los otros tratamientos, incluidos los que se mantuvieron a la temperatura recomendada como confort térmico durante todo el período experimental.
10
Makertihartha, I. G. B. N., Khoiruddin, Ahmad N. Hakim, P. T. P. Aryanti et I. G. Wenten. « Hydrogenation of Maltose in Catalytic Membrane Reactor for Maltitol Production ». MATEC Web of Conferences 156 (2018) : 08008. http://dx.doi.org/10.1051/matecconf/201815608008.
Texte intégralRésumé :
Maltitol is one of the low-calorie sweeteners which has a major role in food industries. Due to its characteristics of comparable sweetness level to sucrose, maltitol can be a suitable sugar replacement. In this work, catalytic membrane reactor (CMR) was examined in maltitol production through hydrogenation of maltose. Commercial ceramic membrane impregnated with Kalcat 8030 Nickel was used as the CMR. The reaction was conducted at a batch mode operation, 95 to 110°C of temperature, and 5 to 8 bar of pressure. In the range of working conditions used in this study, up to 47% conversion was achieved. The reaction conversion was significantly affected by temperature and pressure. Results of this preliminary study indicated that CMR can be used for hydrogenation of maltose with good performance under a relatively low operating pressure.
Thèses sur le sujet "Conversione calore"
1
Nuzziello, Michela. « Sistemi di conversione energetica ibridi termo-fotovoltaici ». Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/3547/.
Texte intégral
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FACCHINETTI, IRENE. « Thermally Regenerable Redox-Flow Batteries ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2021. http://hdl.handle.net/10281/308694.
Texte intégralRésumé :
Il calore a bassa temperatura (LTH), inferiore a 100°C, è una forma di energia largamente disponibile che viene dispersa nell’ambiente, senza alcun utilizzo. La conversione di questo tipo di energia in elettricità aprirebbe le porte allo sfruttamento di fonti energetiche come il calore solare, geotermico e di scarto industriale.
La conversione di LTH in elettricità non è però un processo efficiente a causa dei limiti posti dalla termodinamica, con la cosiddetta legge di Carnot, oltre che ai limiti tecnologici che riducono ulteriormente la conversione di questa forma di energia.
I dispositivi preposti per convertire LTH in elettricità devono poter operare con alte efficienze e potenze, e devono essere facilmente scalabili ed economici. Purtroppo, attualmente nessun dispositivo è in grado di effettuare questa conversione con potenze ed efficienze abbastanza elevate da giustificare gli alti costi (materiali, operazionali e manutenzione) e la complessità dei dispositivi stessi ed è per questo motivo che LTH non trova tutt’ora alcuna applicazione
Questo progetto di ricerca si è focalizzato sullo sviluppo di un dispositivo in grado di convertire LTH in maniera efficiente e con alte potenze. Tale dispositivo, chiamato Thermally Regnerable Redox-Flow Battery, TRB, è una batteria a flusso ricaricabile termicamente. Il dispositivo conta due diverse processi: la produzione energetica, che avviene in una cella elettrochimica in grado di produrre elettricità alle spese dell’energia libera di mescolamento di due soluzioni acquose dello stesso sale ma a diversa concentrazione. Quando le due soluzioni raggiungono la stessa concentrazione, la soluzione esausta viene mandata al secondo processo: un distillatore sottovuoto che rigenera il gradiente di concentrazione tra le due soluzioni sfruttando risorse di LTH. L’efficienza totale del dispositivo è quindi data dal prodotto tra l’efficienza della cella elettrochimica e l’efficienza del distillatore.
Studi termodinamici dimostrano che per incrementare tale efficienza è fondamentale lavorare sull’efficienza del distillatore, il cui valore dipende dalla scelta del soluto e del solvente. In particolare, per questo lavoro di ricerca si è scelto di operare con soluzioni acquose di NaI/I2 e LiBr/Br2.
I risultati raggiunti e le principali attività di ricerca vengono riportate brevemente in questo abstract:
Con la determinazione dei coefficienti di attività, si è calcolato l’energia libera di mescolamento e il potenziale a circuito aperto per entrambi i set di soluzioni (NaI e LiBr).
Le celle elettrochimiche sono state sviluppate specificamente per entrambi I sistemi studiati e test elettrochimici hanno permesso di valutare le performance dei due dispositivi, come potenza ed efficienza elettrochimica. La distillazione è stata modellizzata in modo da definire le condizioni ottimali di lavoro e determinare l’efficienza del processo.Low-Temperature Heat (LTH), below of 100°C, has elicited great interest among the scientific community, as a source of energy since it does not see any form of utilization as it is currently simply released into the environment. Its conversion would open the doors to the exploitation of a huge amount of energy as well, such as geothermal, solar, and industrial waste heat. The conversion efficiencies of LTH are low because of the limitations imposed by Carnot law, as well as the existence of technological limits which further reduce the efficiency of the conversion of LTH. In order to be suitable for extensive industrial production, LTH converters should show high power densities, scalable and efficient whilst being cost-effective; to this point, the devices proposed for this afore mentioned application all failed to achieve suitable efficiencies and power density, making the LTH conversion unfeasible. This PhD project was focused on the design of a device called Thermally Regenerable Redox-Flow Battery (TRB) consisting of a redox-flow battery that can be recharged by a thermal process. The device is based upon a two-stages technology composed by a “power production” stage and a “thermal” stage: power production happens in an electrochemical cell which release electricity at the expenses of the mixing free energy of two water solutions of the same salt at different concentrations, referred to as a concentration cell. When the two solutions reach the same concentration, the exhausted fluid is sent to the second stage, the thermal process, which regenerates the initial mixing free energy, by exploiting LTH sources, through vacuum distillation. The efficiency of the technology is the product between the efficiencies of the units in the device where both stages happen: the electrochemical cell, engineered for power production, and a distillation unit, designed to be responsible for thermal conversion. NaI/I2 and LiBr/Br2 water solutions will be the most discussed redox couple in this thesis, as result of thermodynamic analysis that have shown the importance related to the solvent and salt choice to ensure high energy conversion efficiencies. The achieved results, as well as the main research activities, are briefly reported here: starting from the determination of the activity coefficients, mixing free energy of the initial solutions, and the open circuit voltage of the electrochemical are calculated. Electrochemical cells are specifically designed for both systems while electrochemical tests are performed to evaluate the main performances of the devices, such as power density and electrochemical efficiency. Modeling of the operational conditions of the thermal stage allows to determine the distillation efficiency for both the solutions. The initial experiments prove an unprecedented heat-to-electricity efficiency for both the systems: 3% for TRB-NaI and 4-5% for TRB based on LiBr, depending on the thickness of the membrane with a power density output of almost 10 W m-2 for both technologies, which opens various possibilities to implement further improvements into this new class of energy storage/converter devices.
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Neves, Marcus Godolphim de Castro [UNESP]. « Estudo da viabilidade de implantação de plantas para conversão de energia térmica do oceano (OTEC) no Brasil ». Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/124434.
Texte intégralRésumé :
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000836695.pdf: 1571978 bytes, checksum: 4e307c80099ecf2308070178e4aa39ab (MD5)Atualmente, a busca por novas fontes de energias renováveis tem sido o motivo de pesquisas e investimentos, sendo que a possibilidade de exploração da energia dos oceanos pode ser uma interessante alternativa. Um desses processos é baseado na extração da energia térmica solar acumulada na superfície dos oceanos. Parte dessa energia pode ser transformada em eletricidade e em vários outros subprodutos por meio de um processo conhecido como Conversão da Energia Térmica dos Oceanos (OTEC), que utiliza a água fria obtida a partir de uma profundidade de 1.000 m. As usinas OTEC podem operar em sistemas térmicos aberto, fechado ou híbrido, sendo que, para operar de forma adequada, o local de instalação da usina OTEC deve ter águas com temperatura média da superfície maior que 24 °C. O Brasil possui várias regiões que atendem esta condição sendo, portanto, um dos países com boa capacidade de instalação de usina OTEC para ajudar a suprir sua demanda energética. Este trabalho apresenta o estudo de viabilidade termodinâmica, termoeconômica e econômica de instalação de uma usina OTEC no Brasil por meio de simulações numéricas de seis casos de ciclos fechados, sendo cinco deles com um estágio (três com coletores solares e dois sem); e um caso com dois estágios, sem coletor solar. Os resultados mostraram que a planta com dois estágios não se mostrou viável. No entanto, observou-se que uma usina com ciclo fechado, com um estágio, é capaz de produzir de 13 a 19 MW, dependendo do caso, com custo entre R$ 0,55 (com coletor) e R$ 0,65 (sem coletor) por kW. Esse valor é inferior ao custo da energia produzida por motores estacionários a Diesel, de modo que essa tecnologia pode ser uma alternativa viável e sustentável para substituição dessa forma de geração de eletricidade no nordeste do Brasil, sendo também capaz de produzir água dessalinizada e sal
The search for new sources of clean renewable energy has been the subject of current research and investment, and the possible exploration of oceanic processes may be an interesting alternative. One of these processes is based on extraction of the solar thermal energy accumulated in the ocean upper layer. A fraction of this energy can be converted into electricity and various byproducts by means of a conversion process known simply as Ocean Thermal Energy Conversion (OTEC), which uses the cold water gotten from a depth of 1,000 m. OTEC plants operate in three distinct thermal cycles: open, closed and hybrid. To operate in an adequate form, the local of installation of an OTEC plant must have the sea's average surface temperature greater than 24 oC. Brazil has several offshore regions with these conditions, being one of the countries with good capacity to install OTEC plants to help to supply the electrical and energy demands. This work presents the study of thermodymanic, thermoeconomic and economic feasibility to install an OTEC plant in Brazil through numerical simulation of six cases of closed thermal cycles of an OTEC plant, being five of them with one stage (three with and two without solar boosters); one case with two stages and none solar booster. The results have shown that the two-stage plant has not been feseable. However, the one-stage closed cycle plants are able to produce between 13 to 19 MW, depending on the case considered, with cost between R$ 0,55 (with solar booster) and R$ 0,65 (without solar booster) per kW. These values is lower than the energy cost produced by Diesel stationary engines, so that this technology may be a feseable and sustainable alternative to replace this kind of power generation in Brazilian Northeast region, being able to produce fresh water and salt too
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Neves, Marcus Godolphim de Castro. « Estudo da viabilidade de implantação de plantas para conversão de energia térmica do oceano (OTEC) no Brasil / ». Ilha Solteira, 2015. http://hdl.handle.net/11449/124434.
Texte intégralRésumé :
Orientador: Ricardo Alan Verdú RamosCo-orientador: Cassio Roberto de Macedo Maia
Banca: Emanuel Rocha Woiski
Banca: Mauro Conti Pereira
Resumo: Atualmente, a busca por novas fontes de energias renováveis tem sido o motivo de pesquisas e investimentos, sendo que a possibilidade de exploração da energia dos oceanos pode ser uma interessante alternativa. Um desses processos é baseado na extração da energia térmica solar acumulada na superfície dos oceanos. Parte dessa energia pode ser transformada em eletricidade e em vários outros subprodutos por meio de um processo conhecido como Conversão da Energia Térmica dos Oceanos (OTEC), que utiliza a água fria obtida a partir de uma profundidade de 1.000 m. As usinas OTEC podem operar em sistemas térmicos aberto, fechado ou híbrido, sendo que, para operar de forma adequada, o local de instalação da usina OTEC deve ter águas com temperatura média da superfície maior que 24 °C. O Brasil possui várias regiões que atendem esta condição sendo, portanto, um dos países com boa capacidade de instalação de usina OTEC para ajudar a suprir sua demanda energética. Este trabalho apresenta o estudo de viabilidade termodinâmica, termoeconômica e econômica de instalação de uma usina OTEC no Brasil por meio de simulações numéricas de seis casos de ciclos fechados, sendo cinco deles com um estágio (três com coletores solares e dois sem); e um caso com dois estágios, sem coletor solar. Os resultados mostraram que a planta com dois estágios não se mostrou viável. No entanto, observou-se que uma usina com ciclo fechado, com um estágio, é capaz de produzir de 13 a 19 MW, dependendo do caso, com custo entre R$ 0,55 (com coletor) e R$ 0,65 (sem coletor) por kW. Esse valor é inferior ao custo da energia produzida por motores estacionários a Diesel, de modo que essa tecnologia pode ser uma alternativa viável e sustentável para substituição dessa forma de geração de eletricidade no nordeste do Brasil, sendo também capaz de produzir água dessalinizada e sal
Abstract: The search for new sources of clean renewable energy has been the subject of current research and investment, and the possible exploration of oceanic processes may be an interesting alternative. One of these processes is based on extraction of the solar thermal energy accumulated in the ocean upper layer. A fraction of this energy can be converted into electricity and various byproducts by means of a conversion process known simply as Ocean Thermal Energy Conversion (OTEC), which uses the cold water gotten from a depth of 1,000 m. OTEC plants operate in three distinct thermal cycles: open, closed and hybrid. To operate in an adequate form, the local of installation of an OTEC plant must have the sea's average surface temperature greater than 24 oC. Brazil has several offshore regions with these conditions, being one of the countries with good capacity to install OTEC plants to help to supply the electrical and energy demands. This work presents the study of thermodymanic, thermoeconomic and economic feasibility to install an OTEC plant in Brazil through numerical simulation of six cases of closed thermal cycles of an OTEC plant, being five of them with one stage (three with and two without solar boosters); one case with two stages and none solar booster. The results have shown that the two-stage plant has not been feseable. However, the one-stage closed cycle plants are able to produce between 13 to 19 MW, depending on the case considered, with cost between R$ 0,55 (with solar booster) and R$ 0,65 (without solar booster) per kW. These values is lower than the energy cost produced by Diesel stationary engines, so that this technology may be a feseable and sustainable alternative to replace this kind of power generation in Brazilian Northeast region, being able to produce fresh water and salt too
Mestre
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Golden, Michelle. « The "Root of Civil Conversion" : Redefining Courtesy in Book VI of the Faerie Queene ». Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/english_hontheses/4.
Texte intégralRésumé :
Book Six of The Faerie Queene deals with the complexities of courtesy in a socially changing world. Calidore, the protagonist of Book Six, sets out to defeat the Blatant Beast, the chief enemy of courtesy, but abandons his quest midway through the book in order to live the shepherds’ life. Despite the ethical ambiguity associated with Calidore’s abandoning his quest, this pastoral setting should enable him to deepen his understanding of the nature and practice of courtesy. However, Calidore is unable to grow, and the poet essentially gives up on his own poetic quest.
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Frazão, Marco Antonio Gomes 1975. « Avaliação da influência do calor e da luz solar na densidade de filmes radiográficos impressos ». [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288919.
Texte intégralRésumé :
Orientador: Frab Norberto BóscoloTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
Made available in DSpace on 2018-08-22T13:39:06Z (GMT). No. of bitstreams: 1 Frazao_MarcoAntonioGomes_D.pdf: 4262109 bytes, checksum: 0e3256f8a0dd02738990d526d5a2329b (MD5) Previous issue date: 2012
Resumo: Com este estudo, teve-se a proposta de avaliar a modificação da densidade de 4 cores (branco, cinza claro, cinza escuro e preto) em filmes radiográficos impressos por duas tecnologias dry seca: termográfica (AGFA) e fototermográfica (KODAK). Para isso, foi utilizada uma amostra formada por 18 grupos com 6 corpos de prova para cada uma das tecnologias de impressão totalizando um experimento com 216 corpos de prova submetidos às temperaturas de 40ºC, 60ºC e 80ºC, pelos tempos de 30, 60 e 120 minutos com e sem a exposição solar. Nestes foram realizadas analises densitométricas antes e depois da exposição aos fatores estudados e os dados obtidos submetidos aos testes estatísticos de: Kruskal Wallis, Mann-Whitney e Wilcoxon para dados pareados com nível de significância de 5%. Pôde-se observar que as cores avaliadas impressas no filme pela tecnologia termográfica (AGFA) modificam sua densidade a partir de combinações de exposição a 60ºC e 120 minutos e a 80ºC e 30 minutos sem a exposição ao sol e a partir de 40ºC e 30 minutos com exposição solar, e no filme impresso pela tecnologia fototermográfica (KODAK) modifica sua densidade a 40ºC a partir de 30 minutos com e sem a exposição solar. Concluiu-se que o aumento da temperatura de armazenamento bem com a exposição à luz solar modificam a densidade dos filmes radiográficos impressos pelas tecnologias dry seca avaliadas
Abstract: The purpose of this study was to evaluate the density modification of 4 colors (white, light gray, dark gray and black) in films printed by two dry technologies: thermographic (AGFA) and photothermographic (KODAK). A sample consisting of 18 groups with six specimens per printing technologies was used, totaling an experiment of 216 evaluated specimens when subjected to temperatures of 40°C, 60°C and 80°C, for periods of 30, 60 and 120 minutes with and without sunlight exposure. These specimens were submitted to densitometric analysis before and after exposure to the studied factors and data were subjected to the following statistical tests: Kruskal Wallis, Mann-Whitney and Wilcoxon for paired data. It was observed that the evaluated colors printed on the film by thermographic technology (AGFA) modify their density at exposures to 60°C and 120 minutes, and without sunlight exposure at the temperature of 80°C after 30 minutes, and with sunlight exposure from 40°C and 30 minutes, and the film printed by photothermographic technology (KODAK) modifies its density at 40°C from 30 minutes with and without sunlight exposure. It was concluded that the increase of storage temperature and sunlight exposure modify the density of radiographic films printed by dry technologies
Doutorado
Radiologia Odontologica
Doutor em Radiologia Odontológica
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Sánchez, I. Felipe. « Evaluación Técnico-Económica de Obtención de Agua para Riego a Partir de Aguas Salobres Utilizando Energía Solar ». Tesis, Universidad de Chile, 2010. http://www.repositorio.uchile.cl/handle/2250/103826.
Texte intégralRésumé :
En la actualidad existen muchos lugares en el mundo donde el agua dulce es un bien escaso y por ende, económicamente valioso. Para mejorar esta situación se plantea la instalación de una planta de desalinización con el objetivo de aumentar la disponibilidad de agua dulce en zonas donde solo existe agua salobre. El proceso de desalinización requiere gran cantidad de energía. Dicha energía se puede obtener a partir de energía solar, ya que es renovable, sustentable y evita la emisión de gases de efecto invernadero que pueden agravar el problema de carencia de agua.
Los objetivos de este trabajo fueron revisar las distintas tecnologías que existen para la desalinización y para la captura de energía solar con el fin de poder realizar una evaluación económica simplificada sobre la implementación de una planta de desalinización.
Se construyó un prototipo concentrador de radiación solar, original de inspiración Fresnel, para poder estudiar eficiencias del diseño. El prototipo consiste de secciones cónicas con un mismo foco construido con acero brillante y en el foco un receptor de radiación que transfiere calor hacia un fluido térmico. El equipo de laboratorio tuvo una eficiencia de 70% del calor transferido al fluido térmico sobre la radiación, cercano al valor teórico calculado de 77%. Con el dato de eficiencia real se pueden diseñar concentradores industriales a partir del prototipo construido.
Se realizaron tres evaluaciones económicas para distintos escenarios que se diferencian entre sí por la tecnología de desalinización y el suministro de energía. Para los tres escenarios se consideró una tasa de descuento del 10%, un horizonte de evaluación de 10 años y un requerimiento de producción de 1.000 [m3/día]. Los concentradores dimensionados para las evaluaciones son de 8 [m] de diámetro, totalizando un área de concentración de 40,81 [m2] por concentrador. Para cada escenario se evalúa el agua obtenida para riego de cultivos (tomates) y para uso sanitario.
El primer escenario usa una tecnología de destilación que requiere para su funcionamiento 442 concentradores que suman 1,8 [ha] de concentración con lo que se obtiene una eficiencia de 555,6 [(m3 de agua desalinizada)/día/(ha de concentración)] obteniéndose una capacidad de riego de cultivo de tomates de 5,23 [ha/(ha de concentración)]. Todos los escenarios expuestos son para el caso de la venta de agua para uso sanitario ya que tienen un mayor retorno. El VAN resultó ser de - $119.000.000 (préstamo del 75%) para una inversión de $1.243.000.000. Para el segundo escenario se utiliza una tecnología de desalinización por membrana con energía eléctrica del sistema interconectado. El VAN resultó ser $44.000.000 (préstamo del 75%) para una inversión de $530.000.000. El tercer escenario usa una tecnología de desalinización por membrana con energía eléctrica por parte de los concentradores. El VAN resultó ser $212.000.000 (préstamo del 75%) para una inversión de $796.000.000.
Se plantea realizar la evaluación técnica y económica para otros materiales reflectivos del concentrador para mejorar eficiencias y también considerar bonos de carbono para aumentar la rentabilidad de los proyectos.
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Richard, Nicolas. « Farní klerus a náboženská proměna v pražské arcidiécezi od tridenstkého koncilu do konce 17. století ». Doctoral thesis, 2013. http://www.nusl.cz/ntk/nusl-328194.
Texte intégralRésumé :
Parish clergy and religious change in Prague's diocese from Council of Trent till the end of the 17th century The religious change that happens in Bohemia in the 17th century has no equivalent in the Europe at this time: the whole country, where Catholics were in a very minority, comes back to the roman Church. This evolution is here seen from a very prosaic point of view: how lay people live this change, and so how acts the parish clergy in this matter. Conversion's strategy, at the end of the Council of Trent, was to permit the use of the chalice to the laity. The consequence of this permission was a very hazy situation in the parishes, but Holy See did nothing before the battle of White Mountain, and after the battle, he suppressed chalice, mainly for pastoral reasons. During the Thirty years War, the kingdom is the place of a general reform, which has its origins in the catholic missionary movement of the beginning of the century and in the political theories of this time. Bohemia is strongly marked by the war that acts as a catalyst; at the same time political and religious authorities were lacking. The inhabitants, usually just formal Catholics at the beginning, convert themselves more and more deeply during the 17th century. The eldest, who remembered the non-Catholics services, died during the...
Livres sur le sujet "Conversione calore"
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Soghier, Lamia, Katherine Pham et Sara Rooney, dir. Reference Range Values for Pediatric Care. American Academy of Pediatrics, 2014. http://dx.doi.org/10.1542/9781581108545.
Texte intégralRésumé :
Here’s the one place to look for normal values and related need-to-know data! Now you no longer have to search through multiple resources for reference ranges and other critical values you need to optimize patient assessment and management. The new Reference Range Values for Pediatric Care brings all the most vital range data - plus diverse clinical evaluation and calculation tools - all together in one concise, compact handbook. Indispensable pediatric reference ranges - right at your fingertips Custom-designed for today’s busy practitioners, this quick-access resource provides commonly used ranges and values spanning birth through adolescence. Data needed for management of preterm newborns and other neonates is highlighted throughout. Look here for practice-focused help with: - Blood pressure ranges - Body surface area calculation - Bone age metrics - Hematology values - Cerebrospinal fluid values - Lymphocyte subset counts - Clinical chemistry ranges - Thyroid function - Umbilical vein and artery catheterization measurements - Caloric intake values - And more! Also includes assessment and management tools you’ll use again and again Save time and simplify clinical problem-solving with a full set of easy-to-use tools from the AAP and other authoritative sources: - APGAR and Ballard newborn screening - Growth charts - Metric conversion tables - Pain scales - Blood pressure nomograms - Hyperbilirubinemia nomograms - Enternal formulas - GIR calculators - AAP immunization schedules - AAP periodicity schedule Drug administration and monitoring guidelines The handbook includes must-know basics on commonly used antibiotics and antiseizure medications - complete with recommended dosages and serum target levels.
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Chiran, Gabriela Aurelia. Limba romana literara in traducerile succesive din Jules Verne. Editura Universitara, 2020. http://dx.doi.org/10.5682/9786062810474.
Texte intégralRésumé :
Lucrarea de fata reprezintă o incercare de cercetare sistematică a fenomenelor și tehnicilor traductologice evidentiate în talmacirile romanesti ale romanului Le Château des Carpathes/ Castelul din Carpati, cu scopul de a releva marcile diacronice ale limbii romane literare, de-a lungul celor o suta douazeci si cinci de ani de confruntare cu scrierile lui Jules Verne. Textul Le Château de Carpathes/Castelul din Carpati, despre care discutam aici, s-a bucurat de un succes deosebit in epoca si in posteritate, ajungand la sensibilitatea cititorilor romani, dar si a traducatorilor, intrucat acesta valorifica o limba literara in care terminologia stiintifica de la nivelul de popularizare a stiintelor se îmbina cu elementele stilului beletristic: un vocabular complex, presarat cu expresii metaforice, cu forme arhaice, regionale, dar mai ales cu imprumuturi, cu neologisme obtinute pe aceasta cale a imprumutului sau prin creatii interne partiale ori totale – calcuri lingvistice, derivate, compuse, conversiuni, combinatii intre toate acestea. In plus, romanul in cauza a reprezentat un prilej de mandrie nationala, dat fiind faptul ca Transilvania, un colt de tara romaneasca, a provocat un interes deosebit pentru anticipatorul stiintific francez – un autor de talie mondiala.
Chapitres de livres sur le sujet "Conversione calore"
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Posner, Jerome B., Clifford B. Saper, Nicholas D. Schiff et Jan Claassen. « Psychogenic Unresponsiveness ». Dans Plum and Posner's Diagnosis and Treatment of Stupor and Coma, 291–304. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780190208875.003.0006.
Texte intégralRésumé :
Chapter 6 explores psychiatric causes of unresponsiveness, which must be differentiated from organic causes of stupor and coma. The chapter notes that several psychiatric disorders can result in psychogenic unresponsiveness. These include conversion reaction, catatonic stupor, a dissociative or “fugue” state, and factitious disorder or malingering. The chapter looks at these in turn. Various diagnostic tests are described in detail, including the electroencephalogram, magnetic resonance imaging, computed tomographic imaging, caloric testing, and the “Amytal interview.” Sections describes the diagnosis and treatment of catatonia, psychogenic seizures (which must be differentiated from epileptic seizures), and cerebellar mutism. The authors emphasize the importance of treating patients with psychiatric causes of unresponsiveness with compassion and understanding.
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Gladchenko, Marina A., et Sergey N. Gaydamaka. « Optimization of the anaerobic conversion of green biomass into volatile fatty acids for further production of high-calorie liquid fuel ». Dans Advances of Artificial Intelligence in a Green Energy Environment, 67–82. Elsevier, 2022. http://dx.doi.org/10.1016/b978-0-323-89785-3.00007-4.
Texte intégralActes de conférences sur le sujet "Conversione calore"
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Misyukova, A. D., A. A. Galaktionova, K. D. Fedorko et S. A. Yankovsky. « Thermal conversion of BSG to produce high-calorie bio-carbon ». Dans HEAT AND MASS TRANSFER IN THE THERMAL CONTROL SYSTEM OF TECHNICAL AND TECHNOLOGICAL ENERGY EQUIPMENT (HMTTSC 2021). AIP Publishing, 2021. http://dx.doi.org/10.1063/5.0068072.
Texte intégral
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Wyczalek, Floyd, Michael Wyczalek et Tonya Wyczalek. « CALERA CO2 Sequestration and Enhanced Geothermal Energy ». Dans 10th International Energy Conversion Engineering Conference. Reston, Virigina : American Institute of Aeronautics and Astronautics, 2012. http://dx.doi.org/10.2514/6.2012-4246.
Texte intégral
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Ferreiro García, Ramón, José Luis Calvo Rolle et Francisco Javier Pérez Castelo. « Control de la expansión isotérmica para conversión de calor a trabajo mecánico ». Dans Actas de las XXXVII Jornadas de Automática 7, 8 y 9 de septiembre de 2016, Madrid. Universidade da Coruña, Servizo de Publicacións, 2022. http://dx.doi.org/10.17979/spudc.9788497498081.0001.
Texte intégralRésumé :
A consecuencia de recientes avances en las técnicas de conversión de energía térmica a trabajo mecánico basadas en procesos de expansión isotérmica, surge la necesidad de controlar la temperatura de los procesos de expansión. Dado que la velocidad de las máquinas térmicas tiene que ser alta para favorecer tanto la eficiencia térmica como el trabajo específico, se hace imprescindible la aplicación de técnicas de control dotadas de alta velocidad de muestreo. Este artículo aborda el estudio preliminar en caminado a la implementación de máquinas de expansión isotérmica en base a la utilización de algoritmos de control de temperatura durante la expansión isotérmica. Se proponen estructuras algorítmicas de control susceptibles de aplicación utilizando tanto medidas directas como indirectas de medición por conversión de las señales para obtener resultados técnica y económicamente viables.
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Robinson, Megan, et Zoya Popovic. « SCALABLE MICROWAVE WASTE-TO-FUEL CONVERSION ». Dans Ampere 2019. Valencia : Universitat Politècnica de València, 2019. http://dx.doi.org/10.4995/ampere2019.2019.9839.
Texte intégralRésumé :
This paper presents an efficiency study for scalable microwave waste management. When waste with carbon content is subjected to volume power densities on the order of 0.25W/cm3 at GHz frequencies, it converts to solid coke fuel with oil and gas bi-products that can further be processed for fuel, leaving no trace. For an efficient process, a well-controlled uniform RF field should be maintained in a non-uniform and time-variable material. We are developing a 2.45-GHz active microwave cavity with solid-state (GaN) spatially power combined sources for lower volumes, Fig.1. In the energy balance calculations, the input energy into the system consists of the waste chemical energy and the DC electrical energy used to obtain the RF power with an efficiency that can reach 70% for kW power levels. The efficiency of RF power conversion to heat in the waste mass is calculated from full-wave simulations for typical waste mixtures and ranges from 10 to 90% depending on the material and cavity filling. The output energy estimates are collected from various pyrolysis process descriptions, e.g. [1], with the total energy being that of the solid fuel (35MJ/kg) and oil caloric values, e.g. 40MJ/kg for plastics and about 10-15MJ/kg for nonplastics [2]. A byproduct is flue gas which can be converted to Syngas [3]. The total worse-case carbon footprint balance (0.3-3) calculations will be presented. Fig. 1. Block diagram of active microwave cavity for waste to fuel conversion. References D. Czajczyńska, “Potential of pyrolysis processes in the waste management sector,” Thermal Science and Engineering Progress, vol. 3, p. 171. Sept., 2017. J.A. Onwudili, “Composition of products from the pyrolysis of polyethylene and polystyrene in a closed batch reactor: effects of temperature and residence time,” Journal of Analytical and Applied Pyrolysis, vol. 86 p. 293–303. Nov., 2009. S. Chunshan, "Tri-reforming of methane: a novel concept for synthesis of industrially useful synthesis gas with desired H2/CO ratios using CO2 in flue gas of power plants without CO2 separation." Prepr. Pap.-Am. Chem. Soc., Div. Fuel Chem 49, no. 1 (2004): 128.
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Danov, Stanislav N., et Ashwani K. Gupta. « Influence of Imperfections in Working Media on Diesel Engine Indicator Process : Part 1 — Theory ». Dans ASME 1998 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/detc98/cie-6026.
Texte intégralRésumé :
Abstract Several improvements to the mathematical model of the indicator process, taking place in a diesel engine cylinder, are proposed. The thermodynamic behavior of working media is described by the equation of state, valid for real gases. Analytical mathematical dependencies between thermal parameters (pressure, temperature, volume) and caloric parameters (internal energy, enthalpy, specific heat capacities) have been obtained. These equations have been applied to the various products encountered during the burning of fuel and the gas mixture as a whole in the engine cylinder under conditions of high pressures and temperatures. An improved mathematical model, based on the first law of thermodynamics, has been developed by taking into account imperfections in the working media that appear under high pressures and temperatures. The numerical results show that there are significant differences between the values calculated using ideal gas behavior and the real gas, in particular at high pressure and high temperature conditions. The numerical experiments show that if the pressure is above 8 to 9 MPa, the imperfections in working medium must be taken into consideration. The results obtained from the mathematical dependency of the caloric parameters can also be used to model any energy conversion and combustion process, such as, advanced gas turbine engines which operate at high pressure ratios, rockets.
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Danov, Stanislav N., et Ashwani K. Gupta. « Influence of Imperfections in the Working Media on Diesel Engine Indicator Process : Part 2 — Results ». Dans ASME 1998 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/detc98/cie-6027.
Texte intégralRésumé :
Abstract In the companion Part 1 of this two-part series paper several improvements to the mathematical model of the energy conversion processes, taking place in a diesel engine cylinder, have been proposed. Analytical mathematical dependencies between thermal parameters (pressure, temperature, volume) and caloric parameters (internal energy, enthalpy, specific heat capacities) have been obtained. These equations have been used to provide an improved mathematical model of diesel engine indicator process. The model is based on the first law of thermodynamics, by taking into account imperfections in the working media which appear when working under high pressures and temperatures. The numerical solution of the simultaneous differential equations is obtained by Runge-Kutta type method. The results show that there are significant differences between the values calculated by equations for ideal gas and real gas under conditions of high pressures and temperatures. These equations are then used to solve the desired practical problem in two different two-stroke turbo-charged engines (8DKRN 74/160 and Sulzer-RLB66). The numerical experiments show that if the pressure is above 8 to 9 MPa, the working medium imperfections must be taken into consideration. The mathematical model presented here can also be used to model combustion process of other thermal engines, such as advanced gas turbine engines and rockets.
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Brenna, J. Thomas. « How does knowledge of omega-3 fatty acids inform the food system ? » Dans 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/cfsw6115.
Texte intégralRésumé :
With over 40,000 studies published, omega-3s are among most studied compounds in all of biology. We know a great deal about their metabolism, genetics, and nutrition that has not been translated into the global industrial food system. Development and maintenance of the human and general neural function depends on a balanced nutritional supply of omega-6 and omega-3 PUFA. Omega-3s are the most labile of oil components, leading to rancidity during processing and limiting shelf-life. Recent research has clarified the roles of the human FADS1 and FADS2 genes as key to conversion of precursor alpha-linolenic acid (ALA) to bioactive products eicosapentaenoic acid (EPA) and docosahexaenoic acid ((DHA). FADS2 is a promiscuous desaturase enzyme that inserts double bonds at the 4, 6, and 8 positions and acts on at least 16 substrates including numerous saturated fatty acids, while FADS1 is highly specific to 5 desaturation and C20 substrates. FADS gene polymorphisms lead primarily to modulation of circulating arachidonic acid in free living humans, which is likely to influence omega-3 requirements through biochemical competition at many levels. Natural, pre-industrial diets are high in saturated and monounsaturated fats, and supply dietary essential fatty acids at less than 4% of calories. Such diets support endogenous EPA and DHA biosynthesis at relatively robust levels, while diets high in PUFA inhibit EPA/DHA tissue accretion and create a metabolic demand. Recent recommendations focus on gently processed healthy foods rich in shortfall nutrients despite high saturated fat content have been advanced. Dietary intake of EPA and DHA have effects specific to each fatty acid, and both are more efficiently incorporated into tissue than when derived from precursors. Current evidence is that both are required for optimal health.
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Herdin, G. R., F. Gruber, D. Plohberger et M. Wagner. « Experience With Gas Engines Optimized for H2-Rich Fuels ». Dans ASME 2003 Internal Combustion Engine Division Spring Technical Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ices2003-0596.
Texte intégralRésumé :
The gas engine is a very efficient possibility of a technological approach for the conversion of chemically bound energy into mechanical or electrical power. Degrees of efficiency achieved thus far through the electrification of natural gas amount to up to 45% depending on the engine size and further potentials are already being opened up. Gas engines therefore do not need to fear a comparison with diesel engines in terms of efficiency. The modern gas engines have considerable advantages regarding emissions. The state of the art for the NOx emissions of natural gas engines can presently be given as 0.7 g/kWh (diesel 5 g NOx/kWh) with practically particle-free combustion. As a result of these features the gas engine is especially suitable for the very efficient process of cogeneration of heat and power, through which total degrees of fuel efficiency of about 90% can be attained. As such, the gas engine is even superior to all previously introduced types of fuel cells. The utilization of H2-rich gases as fuel can be seen as a new field of application of gas engines. Jenbacher AG already has many years of experience in the field of “H2-rich fuels” with optimization of combustion control and mixture formation. The H2 content extend from 100% to very low caloric values of gases in the range of 1.67 MJ/Nm3. The gases to be utilized by the gas engines come primarily from thermal pyrolysis processes of biomass or RDF fuels. A very good efficiency behavior with uncommonly low NOx emissions can be determined as the common result of all gas engine sizes. In the case of the high NH3 content of e.g. wood gas, despite the extreme lean-burn operation through the primary formation of NOx from the fuel, no NOx minimum can be attained. For the future, making the step into H2-rich fuel technology particularly regarding emissions means a big step towards the low NOx concepts and thus the further reduction of engine emissions.
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Pérez Asperilla, Estíbaliz. « Transformando Bankside ». Dans III Congreso Internacional de Investigación en Artes Visuales : : ANIAV 2017 : : GLOCAL. Valencia : Universitat Politècnica València, 2017. http://dx.doi.org/10.4995/aniav.2017.4831.
Texte intégralRésumé :
Bankside supone un claro ejemplo de revitalización urbana puesto que, a pesar de haber sido considerado como una de las zonas más contaminadas de Londres, ha logrado transformarse en un Distrito Cultural mundialmente conocido gracias a la apuesta e inversión en diferentes creaciones artísticas. No sólo se han rehabilitado edificios vacíos y en desuso dando lugar a centros artísticos de suma importancia como es el caso de la conversión de su antigua central eléctrica en lo que ahora se conoce como la Tate Modern –una de las galerías de arte contemporáneo más importantes de Europa–, sino que el arte sale a la calle ilustrando muros, fachadas y dando vida a zonas que aún se encuentran a la espera de su próxima regeneración. La ciudad envuelve al ciudadano/a por completo ofreciendo un Distrito Cultural que se reinventa constantemente dando la posibilidad de que el público no sea un mero espectador, sino de que se sumerja en la historia y cultura del Distrito convirtiéndose a su vez en creador y artista e invitándole a formar parte de las actividades que se desarrollan en diferentes festivales como Merge o el London Design Festival. Muchas de las instalaciones y obras de arte son temporales y/o perecederas. No obstante, algunas de las obras que florecen a lo largo de sus calles y plazas se han ganado su permanencia, tal como sucede con las realizadas alrededor del santuario de the Cross Bones Graveyard. Esta comunicación se enmarca dentro de la investigación Los cinco sentidos del Distrito Cultural en Londres, la cual forma parte del Proyecto de Excelencia 2016-2018 Distritos Culturales: imágenes e imaginarios en los procesos de revitalización de espacios urbanos (Ref. HAR2015-66288-C4-2-P, Plan Nacional I+D).http://dx.doi.org/10.4995/ANIAV.2017.4831
Rapports d'organisations sur le sujet "Conversione calore"
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Shani, Moshe, et C. P. Emerson. Genetic Manipulation of the Adipose Tissue via Transgenesis. United States Department of Agriculture, avril 1995. http://dx.doi.org/10.32747/1995.7604929.bard.
Texte intégralRésumé :
The long term goal of this study was to reduce caloric and fat content of beef and other red meats by means of genetic modification of the animal such that fat would not be accumulated. This was attempted by introducing into the germ line myogenic regulatory genes that would convert fat tissue to skeletal muscle. We first determined the consequences of ectopic expression of the myogenic regulatory gene MyoD1. It was found that deregulation of MyoD1 did not result in ectopic skeletal muscle formation but rather led to embryonic lethalities, probably due to its role in the control of the cell cycle. This indicated that MyoD1 should be placed under stringent control to allow survival. Embryonic lethalities were also observed when the regulatory elements of the adipose-specific gene adipsin directed the expression of MyoD1 or myogenin cDNAs, suggesting that these sequences are probably not strong enough to confer tissue specificity. To determine the specificity of the control elements of another fat specific gene (adipocyte protein 2-aP2), we fused them to the bacterial b-galactosidase reporter gene and established stable transgenic strains. The expression of the reporter gene in none of the strains was adipose specific. Each strain displayed a unique pattern of expression in various cell lineages. Most exciting results were obtained in a transgenic strain in which cells migrating from the ventro-lateral edge of the dermomyotome of developing somites to populate the limb buds with myoblasts were specifically stained for lacZ. Since the control sequences of the adipsin or aP2 genes did not confer fat specificity in transgenic mice we have taken both molecular and genetic approaches as an initial effort to identify genes important in the conversion of a multipotential cell such as C3H10T1/2 cell to adipoblast. Several novel adipocyte cell lines have been established that differ in the expression of transcription factors of the C/EBP family known to be markers for adipocyte differentiation. These studies revealed that one of the genetic programming changes which occur during 10T1/2 conversion from multipotential cell to a committed adipoblast is the ability to linduce C/EBPa gene expression. It is expected that further analysis of this gene would identify elements which regulate this lineage-specific expression. Such elements might be good candidates in future attempts to convert adipoblasts to skeletal muscle cells in vivo.