Effect of heat treatment at 600 degree C for 10 hours on human BMP

International Nuclear Information System (INIS)

Izawa, H.; Hachiya, Y.; Muramatsu, K.; Narita, Y.; Kawai, T.

1999-01-01

Viral infection are an extremely serious in allogeneic bone transplantations. While it is essential to kill viruses such as HIV in allogeneic bone graft, the osteoinductive activity must be preserved. Heat treatment of allogeneic bone graft at 60 degree C for 10 hours is effective in killing viruses such as HIV, but it is unclear to what extent the activity of human bone morphogenetic protein (hBMP) is preserved. In this experiment crude hBMP was extracted from both heated and non-heated human bones which were decalcified by the Urist method. Gelatin capsules containing 5mg of crude hBMP were transplanted into the thigh muscles of 5 week old mice. Human bone samples heated in a water bath at 60 degree C for 10 hours and non-heated samples were each transplanted into 5 mice. At 20 days after transplantation, the heterotopic bone formation was compared by evaluation of X-ray and histologicic analysis. X-rays showed heterotopic bone formation in both heated and non-heated samples. Further, histologic analysis showed that peripheral osteoid tissue had developed into laminar bone formation and interlaminar bone marrow was observed. Heterotopic bone formation was induced by crude hBMP from heated bones in a similar way to crude hBMP from non-heated bones observed in X-ray. There was no significant difference in histologic analysis. The crude hBMP, extracted from bones which were heat-treated at 60 degree C for 10 hours induced heterotopic bone formation similar to that in non-heated bone observed by X-ray and histologic analysis at 20 days after transplantation. This demostrates that the heat-treated bone preserved osteoinduction

Spatial distributions of heating, cooling, and industrial degree-days in Turkey

Science.gov (United States)

Yildiz, I.; Sosaoglu, B.

2007-11-01

The degree-day method is commonly used to estimate energy consumption for heating and cooling in residential, commercial and industrial buildings, as well as in greenhouses, livestock facilities, storage facilities and warehouses. This article presents monthly and yearly averages and spatial distributions of heating, cooling, and industrial degree-days at the base temperatures of 18 °C and 20 °C, 18 °C and 24 °C, and 7 °C and 13 °C, respectively; as well as the corresponding number of days in Turkey. The findings presented here will facilitate the estimation of heating and cooling energy consumption for any residential, commercial and industrial buildings in Turkey, for any period of time (monthly, seasonal, etc.). From this analysis it will also be possible to compare and design alternative building systems in terms of energy efficiencies. If one prefers to use set point temperatures to indicate the resumption of the heating season would also be possible using the provided information in this article. In addition, utility companies and manufacturing/marketing companies of HVAC systems would be able to easily determine the demand, marketing strategies and policies based on the findings in this study.

Influence of the degree of thermal contact in fin and tube heat exchanger

DEFF Research Database (Denmark)

Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

2016-01-01

Present work aims to investigate the significance of thermal contact area between fins and tubes in a heat exchanger. The heat exchanger type selected for the study is a liquid-gas fin and tube heat exchanger. Four different cases namely I, II, III, and IV, based on a variable degree of thermal...... contact between fins and tubes are investigated. Case-I with 100% thermal contact area between the fin and tube is set as a reference to cases-II, III, and IV with a thermal contact area of approximately 70%, 50%, and 35%, respectively. Three-dimensional (3D) steady-state numerical models based on finite...... and to compare the performance of heat exchanger design in different cases. Comparative analysis indicates a significant influence of the degree of the thermal contact area between fin and tube on the overall performance. Case-I is found to have higher overall heat transfer coefficient of 47.332 W/(m2 K), higher...

Claiming mastery of the word : The power of discourse in Ray Bradbury's Fahrenheit 451 and George Orwell's 1984

OpenAIRE

Wien, Henriette

2012-01-01

In this thesis, the main objective is to look at the power of discourse in relation to two dystopian texts, George Orwell’s Nineteen Eighty-Four (1948) and Ray Bradbury’s Fahrenheit 451 (1953). Additionally, the thesis proposes how these two texts, as well as literary texts in general, are suitable for the teaching of English as a foreign language (TEFL) in upper secondary school, especially in terms of a pupil’s personal development. Since a majority of dystopian literary texts are concerned...

Liquid Fuel from Heat-Loving Microorganisms: H2-Dependent Conversion of CO2 to Liquid Electrofuels by Extremely Thermophilic Archaea

Energy Technology Data Exchange (ETDEWEB)

None

2010-07-01

Electrofuels Project: NC State is working with the University of Georgia to create Electrofuels from primitive organisms called extremophiles that evolved before photosynthetic organisms and live in extreme, hot water environments with temperatures ranging from 167-212 degrees Fahrenheit The team is genetically engineering these microorganisms so they can use hydrogen to turn carbon dioxide directly into alcohol-based fuels. High temperatures are required to distill the biofuels from the water where the organisms live, but the heat-tolerant organisms will continue to thrive even as the biofuels are being distilled—making the fuel-production process more efficient. The microorganisms don’t require light, so they can be grown anywhere—inside a dark reactor or even in an underground facility.

Changes in the timing, length and heating degree days of the heating season in central heating zone of China

Science.gov (United States)

Shen, Xiangjin; Liu, Binhui

2016-01-01

Climate change affects the demand for energy consumption, especially for heating and cooling buildings. Using daily mean temperature (Tmean) data, this study analyzed the spatiotemporal changes of the starting date for heating (HS), ending date for heating (HE), length (HL) and heating degree day (HDD) of the heating season in central heating zone of China. Over China’s central heating zone, regional average HS has become later by 0.97 day per decade and HE has become earlier by 1.49 days per decade during 1960–2011, resulting in a decline of HL (−2.47 days/decade). Regional averaged HDD decreased significantly by 63.22 °C/decade, which implies a decreasing energy demand for heating over the central heating zone of China. Spatially, there are generally larger energy-saving rate in the south, due to low average HDD during the heating season. Over China’s central heating zone, Tmean had a greater effect on HL in warm localities and a greater effect on HDD in cold localities. We project that the sensitivity of HL (HDD) to temperature change will increase (decrease) in a warmer climate. These opposite sensitivities should be considered when we want to predict the effects of climate change on heating energy consumption in China in the future. PMID:27651063

10 CFR 420.2 - Definitions.

Science.gov (United States)

2010-01-01

... necessary to raise the temperature of one pound of water one degree Fahrenheit at 39.2 degrees Fahrenheit... or instrumentality of a local government exclusive of institutions of higher learning and hospitals...

Solar Air Heating Metal Roofing for Reroofing, New Construction, and Retrofit

Science.gov (United States)

2013-06-01

Fahrenheit ft2 square foot FY fiscal year GHG greenhouse gas HGL HydroGeoLogic, Inc. HVAC heating, ventilation and air-conditioning LPG Liquefied...Petroleum Gas O&M operations and maintenance PV photovaltaic TMY Typical Meteorological Year USACE U.S. Army Corps of Engineers USDA U.S...the greenhouse gas emission reductions; and 6. Document the performance of the solar roof as it compares to a reflective “Cool Roof.” Among the

They’re heating up: Internet search query trends reveal significant public interest in heat-not-burn tobacco products

Science.gov (United States)

Caputi, Theodore L.; Leas, Eric; Dredze, Mark; Cohen, Joanna E.; Ayers, John W.

2017-01-01

Heat-not-burn tobacco products, battery powered devices that heat leaf tobacco to approximately 500 degrees Fahrenheit to produce an inhalable aerosol, are being introduced in markets around the world. Japan, where manufacturers have marketed several heat-not-burn brands since 2014, has been the focal national test market, with the intention of developing global marketing strategies. We used Google search query data to estimate, for the first time, the scale and growth potential of heat-not-burn tobacco products. Average monthly searches for heat-not-burn products rose 1,426% (95%CI: 746,3574) between their first (2015) and second (2016) complete years on the market and an additional 100% (95%CI: 60, 173) between the products second (2016) and third years on the market (Jan-Sep 2017). There are now between 5.9 and 7.5 million heat-not-burn related Google searches in Japan each month based on September 2017 estimates. Moreover, forecasts relying on the historical trends suggest heat-not-burn searches will increase an additional 32% (95%CI: -4 to 79) during 2018, compared to current estimates for 2017 (Jan-Sep), with continued growth thereafter expected. Contrasting heat-not-burn’s rise in Japan to electronic cigarettes’ rise in the United States we find searches for heat-not-burn eclipsed electronic cigarette searches during April 2016. Moreover, the change in average monthly queries for heat-not-burn in Japan between 2015 and 2017 was 399 (95% CI: 184, 1490) times larger than the change in average monthly queries for electronic cigarettes in the Unites States over the same time period, increasing by 2,956% (95% CI: 1729, 7304) compared to only 7% (95% CI: 3,13). Our findings are a clarion call for tobacco control leaders to ready themselves as heat-not-burn tobacco products will likely garner substantial interest as they are introduced into new markets. Public health practitioners should expand heat-not-burn tobacco product surveillance, adjust existing tobacco

They're heating up: Internet search query trends reveal significant public interest in heat-not-burn tobacco products.

Directory of Open Access Journals (Sweden)

Theodore L Caputi

Full Text Available Heat-not-burn tobacco products, battery powered devices that heat leaf tobacco to approximately 500 degrees Fahrenheit to produce an inhalable aerosol, are being introduced in markets around the world. Japan, where manufacturers have marketed several heat-not-burn brands since 2014, has been the focal national test market, with the intention of developing global marketing strategies. We used Google search query data to estimate, for the first time, the scale and growth potential of heat-not-burn tobacco products. Average monthly searches for heat-not-burn products rose 1,426% (95%CI: 746,3574 between their first (2015 and second (2016 complete years on the market and an additional 100% (95%CI: 60, 173 between the products second (2016 and third years on the market (Jan-Sep 2017. There are now between 5.9 and 7.5 million heat-not-burn related Google searches in Japan each month based on September 2017 estimates. Moreover, forecasts relying on the historical trends suggest heat-not-burn searches will increase an additional 32% (95%CI: -4 to 79 during 2018, compared to current estimates for 2017 (Jan-Sep, with continued growth thereafter expected. Contrasting heat-not-burn's rise in Japan to electronic cigarettes' rise in the United States we find searches for heat-not-burn eclipsed electronic cigarette searches during April 2016. Moreover, the change in average monthly queries for heat-not-burn in Japan between 2015 and 2017 was 399 (95% CI: 184, 1490 times larger than the change in average monthly queries for electronic cigarettes in the Unites States over the same time period, increasing by 2,956% (95% CI: 1729, 7304 compared to only 7% (95% CI: 3,13. Our findings are a clarion call for tobacco control leaders to ready themselves as heat-not-burn tobacco products will likely garner substantial interest as they are introduced into new markets. Public health practitioners should expand heat-not-burn tobacco product surveillance, adjust existing

They're heating up: Internet search query trends reveal significant public interest in heat-not-burn tobacco products.

Science.gov (United States)

Caputi, Theodore L; Leas, Eric; Dredze, Mark; Cohen, Joanna E; Ayers, John W

2017-01-01

Heat-not-burn tobacco products, battery powered devices that heat leaf tobacco to approximately 500 degrees Fahrenheit to produce an inhalable aerosol, are being introduced in markets around the world. Japan, where manufacturers have marketed several heat-not-burn brands since 2014, has been the focal national test market, with the intention of developing global marketing strategies. We used Google search query data to estimate, for the first time, the scale and growth potential of heat-not-burn tobacco products. Average monthly searches for heat-not-burn products rose 1,426% (95%CI: 746,3574) between their first (2015) and second (2016) complete years on the market and an additional 100% (95%CI: 60, 173) between the products second (2016) and third years on the market (Jan-Sep 2017). There are now between 5.9 and 7.5 million heat-not-burn related Google searches in Japan each month based on September 2017 estimates. Moreover, forecasts relying on the historical trends suggest heat-not-burn searches will increase an additional 32% (95%CI: -4 to 79) during 2018, compared to current estimates for 2017 (Jan-Sep), with continued growth thereafter expected. Contrasting heat-not-burn's rise in Japan to electronic cigarettes' rise in the United States we find searches for heat-not-burn eclipsed electronic cigarette searches during April 2016. Moreover, the change in average monthly queries for heat-not-burn in Japan between 2015 and 2017 was 399 (95% CI: 184, 1490) times larger than the change in average monthly queries for electronic cigarettes in the Unites States over the same time period, increasing by 2,956% (95% CI: 1729, 7304) compared to only 7% (95% CI: 3,13). Our findings are a clarion call for tobacco control leaders to ready themselves as heat-not-burn tobacco products will likely garner substantial interest as they are introduced into new markets. Public health practitioners should expand heat-not-burn tobacco product surveillance, adjust existing tobacco

Historical trends and current state of heating and cooling degree days in Italy

International Nuclear Information System (INIS)

De Rosa, Mattia; Bianco, Vincenzo; Scarpa, Federico; Tagliafico, Luca A.

2015-01-01

Highlights: • A comparison among methods for calculating heating degree-days (HDD) is provided. • ASHRAE method is used for analyze the historical trends of HDD and CDD in Italy. • The HDD historical profile for Rome is decomposed in its characterizing components. - Abstract: Degree days (DD) represent a versatile climatic indicator which is commonly used in the analysis of building energy performance, as e.g. (i) to perform energetic assessment of existent and new buildings, (ii) to analyze the territory energy consumption, (iii) to develop scenario analyses in terms of energy consumption forecasting, and so on. Different methods can be used for determining the DD values, depending on the available climatic data of each location. In the present paper, the simplified methods based on reduced climatic data set have been compared assuming the mean daily degree-hours method (MDDH) as reference. Hourly temperature profiles recorded by the meteorological station located at the University of Genoa have been used for these analyses. In the second part of the present work, the ASHRAE method has been selected to calculate heating (HDD) and cooling (CDD) degree days for several Italian cities. In particular, daily meteorological data of several Italian cities (covering the whole climatic conditions which occur in Italy) have been used to calculate heating and cooling degree days in the period 1978–2013, in order to analyze their trends in the last years. Finally, the historical profiles of Rome and Milan have been treated as time-series and analyzed in the frequency domain, performing a decomposition of the original data set into different characterizing components. This simplified approach permits to deeply analyze the historical profile of DD and represents a simple starting point method for future analyses with forecasting perspectives

Um Estudo do Discurso Psicanalítico no Filme Fahrenheit 451: a destruição do conhecimento

Directory of Open Access Journals (Sweden)

Paula Puhl

2008-12-01

Full Text Available O presente artigo busca fazer uma análise, a partir do filme Fahrenheit 451, por intermédio da personagem do bombeiro Montag, utilizando as idéias de Gaston Bachelard expostas em suas obras, em especial, em a Psicanálise do Fogo, a fim de verificar o significado do Fogo na obra cinematográfica. O pensamento de Bachelard se caracteriza pela busca da subjetividade na interpretação das imagens, ligando a poesia à ciência, servindo como suporte teórico para a interpretação da comunicação cinematográfica.

Heat resistance of Salmonella in various egg products.

Science.gov (United States)

Garibaldi, J A; Straka, R P; Ijichi, K

1969-04-01

The heat-resistance characteristics of Salmonella typhimurium Tm-1, a reference strain in the stationary phase of growth, were determined at several temperatures in the major types of products produced by the egg industry. The time required to kill 90% of the population (D value) at a given temperature in specific egg products was as follows: at 60 C (140 F), D = 0.27 min for whole egg; D = 0.60 min for whole egg plus 10% sucrose; D = 1.0 min for fortified whole egg; D = 0.20 min for egg white (pH 7.3), stabilized with aluminum; D = 0.40 min for egg yolk; D = 4.0 min for egg yolk plus 10% sucrose; D = 5.1 min for egg yolk plus 10% NaCl; D = 1.0 min for scrambled egg mix; at 55 C (131 F), D = 0.55 min for egg white (pH 9.2); D = 1.2 min for egg white (pH 9.2) plus 10% sucrose. The average Z value (number of degrees, either centigrade or fahrenheit, for a thermal destruction time curve to traverse one logarithmic cycle) was 4.6 C (8.3 F) with a range from 4.2 to 5.3 C. Supplementation with 10% sucrose appeared to have a severalfold greater effect on the heat stabilization of egg white proteins than on S. typhimurium Tm-1. This information should be of value in the formulation of heat treatments to insure that all egg products be free of viable salmonellae.

Pensamento centrado da maioria nômica em Fahrenheit 451: conceitos de Piaget e Moscovici na obra de Ray Bradbury

Directory of Open Access Journals (Sweden)

Mariana Costa Nascimento

2015-06-01

Full Text Available A impressão de livros proporcionou o avanço e quebra de fronteiras, em decorrência de sua circulação mundial advindas da expansão do comércio entre Europa e Ásia. Além disso, repercutiu em mudanças cognitivas, sociais e afetivas para os povos de todo o mundo. O impresso, desde a sua origem passou a ser o novo condutor de ideias. Devido a propagação de crenças e valores, os livros passaram a ser proibidos e queimados em vários países ditatoriais, visto que os impressos poderiam corromper a base social e moral da sociedade. Esse contexto pode ser observado na obra Fahrenheit 451 de Ruy Bradbury. O enredo narra a história de uma cidade em que os livros eram proibidos e como consequência queimados pelos bombeiros que executavam exclusivamente esse ofício. Partindo dessa obra procurou-se convergir os escritos de Bradbury com os conceitos de Jean Piaget e Sergi Moscovici. Os resultados indicam que a articulação entre os autores foi possível, pois a obra Fahrenheit 451 aborda aspectos psicossociais, pertinentes ao desenvolvimento individual e a relação dos grupos sociais formados pelos personagens da literatura. Além disso, a obra problematiza o papel do professor em sala de aula, visto que ao selecionar determinado autor e consequentemente excluir outros, o docente está “queimando” os demais escritores.

Data Quality and Reliability Analysis of U.S. Marine Corps Ground Vehicle Maintenance Records

Science.gov (United States)

2015-06-01

operate in climates 6 ranging from -50 degrees Fahrenheit to 125 degrees Fahrenheit . The MTVR is able to travel at 65mph on improved roads and has...its treatment in the paragraphs below. The MIMMS data comprise 451 distinct UICs. In order to reduce the number of categorical variables within the

Thermal cracking in Lac du Bonnet granite during slow heating to 205 degrees celsius

International Nuclear Information System (INIS)

Chernis, P.J.; Robertson, P.B.

1993-09-01

Acoustic emissions (AE) were recorded as drill core samples of Lac du Bonnet granite were slowly heated to between 66 and 205 degrees celsius to evaluate the effects of temperature on the properties of rock samples. Longitudinal and shear velocities of the samples were measured, and Young's moduli, shear moduli and Poisson's ratios were calculated. No significant AE activity was detected until temperatures reached approximately 73-80 degrees celsius. Above this 'threshold' temperature, calculated rock properties decreased, and at 205 degrees celsius calculated Young's modulus, shear modulus, and Poisson's ratio were reduced by 30, 26, and 29% respectively

Effects of heating on composition, degree of darkness, and stacking nanostructure of soil humic acids

Energy Technology Data Exchange (ETDEWEB)

Katsumi, Naoya, E-mail: n-katsu@ishikawa-pu.ac.jp; Yonebayashi, Koyo; Okazaki, Masanori

2016-01-15

Wildfires and prescribed burning can affect both the quality and the quantity of organic matter in soils. In this study, we investigated qualitative and quantitative changes of soil humic substances in two different soils (an Entisol from a paddy field and an Inceptisol from a cedar forest) under several controlled heating conditions. Soil samples were heated in a muffle furnace at 200, 250, or 300 °C for 1, 3, 5, or 12 h. The humic acid and fulvic acid contents of the soil samples prior to and after heating were determined. The degree of darkness, elemental composition, carbon and nitrogen stable isotope ratios, {sup 13}C nuclear magnetic resonance spectra, and X-ray diffraction patterns of humic acids extracted from the soils before and after heating were measured. The proportion of humic acids in total carbon decreased with increasing heating time at high temperature (300 °C), but increased with increasing heating time at ≤ 250 °C. The degree of darkness of the humic acids increased with increasing heating time and temperature. During darkening, the H/C atomic ratios, the proportion of aromatic C, and the carbon and nitrogen stable isotope ratios increased, whereas the proportions of alkyl C and O-alkyl C decreased. X-ray diffraction analysis verified that a stacking nanostructure developed by heating. Changes in the chemical structure of the humic acids from the heated soils depended on the type of soil. The major structural components of the humic acids from the heated Entisol were aromatic C and carboxylic C, whereas aliphatic C, aromatic C, and carboxylic C structural components were found in the humic acids from the heated Inceptisol. These results suggest that the heat-induced changes in the chemical structure of the humic acids depended on the source plant. - Highlights: • Darkness of humic acids increased with increasing heating time and temperature. • Aromatic carbon content increased during darkening. • Carbon and nitrogen stable isotope

The Omnipresence of Television and the Ascendancy of Surveillance/Sousveillance in Ray Bradbury’s Fahrenheit 451

Directory of Open Access Journals (Sweden)

Hassan Abootalebi

2017-01-01

Full Text Available This paper is an attempt to analyze Ray Bradbury’s Fahrenheit 451(1953 under the light of Jean Baudrillard’s notions on the media and the influences it exerts on people’s daily lives, and with an eye to Michel Foucault’s surveillance as well. The title-mentioned work, it is suggested, portrays a representative sample of a culture where different fields including books, education, and history fall under the influence of the media. Bradbury presents a society in which its inhabitants are bombarded with excessive data transmitted through television most of which is detrimental and not reliable. It is concluded that the presented culture in the novel is a microcosm of contemporary societies where authorities keep their subjects under control, engendering an atmosphere of anxiety, trepidation and apprehension for subversive forces and therefore preclude any disturbance on the part of them

Heat-to-heat variability of irradiation creep and swelling of HT9 irradiated to high neutron fluence at 400-600{degrees}C

Energy Technology Data Exchange (ETDEWEB)

Toloczko, M.B.; Garner, F.A. [Pacific Northwest National Lab., Richland, WA (United States)

1996-10-01

Irradiation creep data on ferritic/martensitic steels are difficult and expensive to obtain, and are not available for fusion-relevant neutron spectra and displacement rates. Therefore, an extensive creep data rescue and analysis effort is in progress to characterize irradiation creep of ferritic/martensitic alloys in other reactors and to develop a methodology for applying it to fusion applications. In the current study, four tube sets constructed from three nominally similar heats of HT9 subjected to one of two heat treatments were constructed as helium-pressurized creep tubes and irradiated in FFTF-MOTA at four temperatures between 400 and 600{degrees}C. Each of the four heats exhibited a different stress-free swelling behavior at 400{degrees}C, with the creep rate following the swelling according to the familiar B{sub o} + DS creep law. No stress-free swelling was observed at the other three irradiation temperatures. Using a stress exponent of n = 1.0 as the defining criterion, {open_quotes}classic{close_quotes} irradiation creep was found at all temperatures, but, only over limited stress ranges that decreased with increasing temperature. The creep coefficient B{sub o} is a little lower ({approx}50%) than that observed for austenitic steel, but the swelling-creep coupling coefficient D is comparable to that of austenitic steels. Primary transient creep behavior was also observed at all temperatures except 400{degrees}C, and thermal creep behavior was found to dominate the deformation at high stress levels at 550 and 600{degrees}C.

Local pool boiling heat transfer on a 3 Degree inclined tube surface

International Nuclear Information System (INIS)

Kang, Myeong Gie

2012-01-01

Mechanisms of pool boiling heat transfer have been studied for a long time. Recently, it has been widely investigated in nuclear power plants for the purpose of acquiring inherent safety functions in case of no power supply. To design more efficient heat exchangers, effects of several parameters on heat transfer must be studied in detail. One of the major issues is variation in local heat transfer coefficients on a tube. Lance and Myers reported that the type of boiling liquid can change the trend of local heat transfer coefficients along the tube periphery. Lance and Myers said that as the liquid is methanol the maximum local heat transfer coefficient was observed at the tube bottom while the maximum was at the tube sides as the boiling liquid was n hexane. Corn well and Einarsson reported that the maximum local heat transfer coefficient was observed at the tube bottom, as the boiling liquid was R113. Corn well and Houston explained the reason of the difference in local heat transfer coefficients along the tube circumference with introducing effects of sliding bubbles on heat transfer. According to Gu pta et al., the maximum and the minimum local heat transfer coefficients were observed at the bottom and top regions of the tube circumference, respectively, using a tube bundle and water. Kang also reported the similar results using a single horizontal tube and water. However, the maximum heat transfer coefficient was observed at the angle of 45 deg. Sateesh et al. investigated variations in local heat transfer coefficients along a tube periphery as the inclination angle was changed. Summarizing the published results, some parts are still remaining to be investigated in detail. Although pool boiling analysis on a nearly horizontal tube is necessary for the design of the advanced power reactor plus, no previous results are published yet. Therefore, the present study is aimed to study variations in local pool boiling heat transfer coefficients for a 3 degree inclined

Heating and cooling building energy demand evaluation; a simplified model and a modified degree days approach

International Nuclear Information System (INIS)

De Rosa, Mattia; Bianco, Vincenzo; Scarpa, Federico; Tagliafico, Luca A.

2014-01-01

Highlights: • A dynamic model to estimate the energy performance of buildings is presented. • The model is validated against leading software packages, TRNSYS and Energy Plus. • Modified degree days are introduced to account for solar irradiation effects. - Abstract: Degree days represent a versatile climatic indicator which is commonly used in building energy performance analysis. In this context, the present paper proposes a simple dynamic model to simulate heating/cooling energy consumption in buildings. The model consists of several transient energy balance equations for external walls and internal air according to a lumped-capacitance approach and it has been implemented utilizing the Matlab/Simulink® platform. Results are validated by comparison to the outcomes of leading software packages, TRNSYS and Energy Plus. By using the above mentioned model, energy consumption for heating/cooling is analyzed in different locations, showing that for low degree days the inertia effect assumes a paramount importance, affecting the common linear behavior of the building consumption against the standard degree days, especially for cooling energy demand. Cooling energy demand at low cooling degree days (CDDs) is deeply analyzed, highlighting that in this situation other factors, such as solar irradiation, have an important role. To take into account these effects, a correction to CDD is proposed, demonstrating that by considering all the contributions the linear relationship between energy consumption and degree days is maintained

No Heat Spray Drying Technology

Energy Technology Data Exchange (ETDEWEB)

Beetz, Charles [ZoomEssence, Inc., Hebron, KY (United States)

2016-06-15

No Heat Spray Drying Technology. ZoomEssence has developed our Zooming™ spray drying technology that atomizes liquids to powders at ambient temperature. The process of drying a liquid into a powder form has been traditionally achieved by mixing a heated gas with an atomized (sprayed) fluid within a vessel (drying chamber) causing the solvent to evaporate. The predominant spray drying process in use today employs air heated up to 400° Fahrenheit to dry an atomized liquid into a powder. Exposing sensitive, volatile liquid ingredients to high temperature causes molecular degradation that negatively impacts solubility, stability and profile of the powder. In short, heat is detrimental to many liquid ingredients. The completed award focused on several areas in order to advance the prototype dryer to a commercial scale integrated pilot system. Prior to the award, ZoomEssence had developed a prototype ‘no-heat’ dryer that firmly established the feasibility of the Zooming™ process. The award focused on three primary areas to improve the technology: (1) improved ability to formulate emulsions for specific flavor groups and improved understanding of the relationship of emulsion properties to final dry particle properties, (2) a new production atomizer, and (3) a dryer controls system.

Shivering heat production and core cooling during head-in and head-out immersion in 17 degrees C water.

Science.gov (United States)

Pretorius, Thea; Cahill, Farrell; Kocay, Sheila; Giesbrecht, Gordon G

2008-05-01

Many cold-water scenarios cause the head to be partially or fully immersed (e.g., ship wreck survival, scuba diving, cold-water adventure swim racing, cold-water drowning, etc.). However, the specific effects of head cold exposure are minimally understood. This study isolated the effect of whole-head submersion in cold water on surface heat loss and body core cooling when the protective shivering mechanism was intact. Eight healthy men were studied in 17 degrees C water under four conditions: the body was either insulated or exposed, with the head either out of the water or completely submersed under the water within each insulated/exposed subcondition. Submersion of the head (7% of the body surface area) in the body-exposed condition increased total heat loss by 11% (P < 0.05). After 45 min, head-submersion increased core cooling by 343% in the body-insulated subcondition (head-out: 0.13 +/- 0.2 degree C, head-in: 0.47 +/- 0.3 degree C; P < 0.05) and by 56% in the body-exposed subcondition (head-out: 0.40 +/- 0.3 degree C and head-in: 0.73 +/- 0.6 degree C; P < 0.05). In both body-exposed and body-insulated subconditions, head submersion increased the rate of core cooling disproportionally more than the relative increase in total heat loss. This exaggerated core-cooling effect is consistent with a head cooling induced reduction of the thermal core, which could be stimulated by cooling of thermosensitive and/or trigeminal receptors in the scalp, neck, and face. These cooling effects of head submersion are not prevented by shivering heat production.

Environmental Assessment (EA): Proposed Missile Storage Improvements, Utah Test and Training Range

Science.gov (United States)

2013-06-11

801) 451 -7872 Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39.18 Hill Air Force Base, Utah Final Environmental Assessment...motors were monitored to determine their functional capability when stored in prescribed temperatures varying between -65 degrees Fahrenheit to 200...degrees Fahrenheit . One of these structures (Building 30260) was used for cryogenic or deep-freeze testing. They were hardened structures meant to

Elastomers for Service as Seals for Engine Lubricants and Hydraulic Fluids

Science.gov (United States)

1976-02-01

mm NBR PNF psi - fluorocarbon rubber - hour per degrees Fahrenheit - inch-pound per cubic inch - minute per degrees Fahrenheit - milliliter...millimeter - nitrile-butadiene rubber - polyffluoroalkoxy)phosphazene - pounds per square inch t I (1 MAT-75-78 <V ■ >«..*, njf:~-. I...I I I I I I r i. L I I 1 ! «WJBDXNB PA« BUNUfOT FIIMID BACKGROUND Nitrile-butadiene robber ( NBR ) O-nngs have had an accept

Impacts of global warming on residential heating and cooling degree-days in the United States.

Science.gov (United States)

Petri, Yana; Caldeira, Ken

2015-08-04

Climate change is expected to decrease heating demand and increase cooling demand for buildings and affect outdoor thermal comfort. Here, we project changes in residential heating degree-days (HDD) and cooling degree-days (CDD) for the historical (1981-2010) and future (2080-2099) periods in the United States using median results from the Climate Model Intercomparison Project phase 5 (CMIP5) simulations under the Representation Concentration Pathway 8.5 (RCP8.5) scenario. We project future HDD and CDD values by adding CMIP5 projected changes to values based on historical observations of US climate. The sum HDD + CDD is an indicator of locations that are thermally comfortable, with low heating and cooling demand. By the end of the century, station median HDD + CDD will be reduced in the contiguous US, decreasing in the North and increasing in the South. Under the unmitigated RCP8.5 scenario, by the end of this century, in terms of HDD and CDD values considered separately, future New York, NY, is anticipated to become more like present Oklahoma City, OK; Denver, CO, becomes more like Raleigh, NC, and Seattle, WA, becomes more like San Jose, CA. These results serve as an indicator of projected climate change and can help inform decision-making.

Impacts of global warming on residential heating and cooling degree-days in the United States

Science.gov (United States)

Petri, Yana; Caldeira, Ken

2015-01-01

Climate change is expected to decrease heating demand and increase cooling demand for buildings and affect outdoor thermal comfort. Here, we project changes in residential heating degree-days (HDD) and cooling degree-days (CDD) for the historical (1981–2010) and future (2080–2099) periods in the United States using median results from the Climate Model Intercomparison Project phase 5 (CMIP5) simulations under the Representation Concentration Pathway 8.5 (RCP8.5) scenario. We project future HDD and CDD values by adding CMIP5 projected changes to values based on historical observations of US climate. The sum HDD + CDD is an indicator of locations that are thermally comfortable, with low heating and cooling demand. By the end of the century, station median HDD + CDD will be reduced in the contiguous US, decreasing in the North and increasing in the South. Under the unmitigated RCP8.5 scenario, by the end of this century, in terms of HDD and CDD values considered separately, future New York, NY, is anticipated to become more like present Oklahoma City, OK; Denver, CO, becomes more like Raleigh, NC, and Seattle, WA, becomes more like San Jose, CA. These results serve as an indicator of projected climate change and can help inform decision-making. PMID:26238673

Quema de libros y antitotalitarismo. Manuel Rivas Los libros arden mal y Ray Bradbury Fahrenheit 451

Directory of Open Access Journals (Sweden)

Mechthild Albert

2015-07-01

Full Text Available El presente artículo se propone comparar dos novelas cuyo común denominador es el compromiso antitotalitario con motivo de la quema de libros considerada como el culmen de la barbarie anticultural, a saber Los libros arden mal (2006 de Manuel Rivas y Fahrenheit 451 (1953 de Ray Bradbury. Partiendo de las reflexiones de Fernando Rodríguez de la Flor en torno al biblioclasmo (2004, el paralelo se centra en los siguientes aspectos: la descripción zoo- y antropomorfizada de los libros en llamas; el biblioclasmo como expresión del totalitarismo, denotando asimismo una relación ambivalente y dialéctica entre cultura y barbarie; los movimientos subversivos dedicados a mantener el culto al libro y la tradición filosófico-literaria; la intertextualidad y el papel destacado de la Biblia en cuanto Libro de los libros. En conclusión se podrá constatar que, a pesar de numerosos puntos en común, en particular su compromiso antitotalitario, ambos autores se distinguen en concreto por su orientación política y el enfoque de su crítica cultural

Extreme degree of ionization in homogenous micro-capillary plasma columns heated by ultrafast current pulses.

Science.gov (United States)

Avaria, G; Grisham, M; Li, J; Tomasel, F G; Shlyaptsev, V N; Busquet, M; Woolston, M; Rocca, J J

2015-03-06

Homogeneous plasma columns with ionization levels typical of megaampere discharges are created by rapidly heating gas-filled 520-μm-diameter channels with nanosecond rise time current pulses of 40 kA. Current densities of up to 0.3  GA cm^{-2} greatly increase Joule heating with respect to conventional capillary discharge Z pinches, reaching unprecedented degrees of ionization for a high-Z plasma column heated by a current pulse of remarkably low amplitude. Dense xenon plasmas are ionized to Xe^{28+}, while xenon impurities in hydrogen discharges reach Xe^{30+}. The unique characteristics of these hot, ∼300:1 length-to-diameter aspect ratio plasmas allow the observation of unexpected spectroscopic phenomena. Axial spectra show the unusual dominance of the intercombination line over the resonance line of He-like Al by nearly an order of magnitude, caused by differences in opacities in the axial and radial directions. These plasma columns could enable the development of sub-10-nm x-ray lasers.

Doublet Tracer Testing in Klamath Falls, Oregon

Energy Technology Data Exchange (ETDEWEB)

Gudmundsson, J S; Johnson, S E; Horne, R N; Jackson, P B [Pet. Eng. Dept., Stanford University; Culver, G G [Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR

0000-12-30

A tracer test was carried out in a geothermal doublet system to study the injection behavior of a developed reservoir known to be fractured. The doublet produces about 320 gpm of 160 degrees Fahrenheit water that is used for space heating and then injected; the wells are spaced 250 ft apart. Tracer breakthrough was observed in 2 hours and 45 minutes in the production well, indicating fracture flow. However, the tracer concentrations were low and indicated porous media flow; the tracers mixed with a reservoir volume much larger than a fracture.

Doublet Tracer Testing in Klamath Falls, Oregon

Energy Technology Data Exchange (ETDEWEB)

Gudmundsson, J.S.; Johnson, S.E.; Horne, R.N.; Jackson, P. B. [Pet. Eng. Dept., Stanford University; Culver, G.G. [Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR

0001-01-01

A tracer test was carried out in a geothermal doublet system to study the injection behavior of a developed reservoir known to be fractured. The doublet produces about 320 gpm of 160 degrees Fahrenheit water that is used for space heating and then injected; the wells are spaced 250 ft apart. Tracer breakthrough was observed in 2 hours and 45 minutes in the production well, indicating fracture flow. However, the tracer concentrations were low and indicated porous media flow; the tracers mixed with a reservoir volume much larger than a fracture.

Natural heat storage in a brine-filled solar pond in the Tully Valley of central New York

Science.gov (United States)

Hayhurst, Brett; Kappel, William M.

2014-01-01

The Tully Valley, located in southern Onondaga County, New York, has a long history of unusual natural hydrogeologic phenomena including mudboils (Kappel, 2009), landslides (Tamulonis and others, 2009; Pair and others, 2000), landsurface subsidence (Hackett and others, 2009; Kappel, 2009), and a brine-filled sinkhole or “Solar pond” (fig. 1), which is documented in this report. A solar pond is a pool of salty water (brine) which stores the sun’s energy in the form of heat. The saltwater naturally forms distinct layers with increasing density between transitional zones (haloclines) of rapidly changing specific conductance with depth. In a typical solar pond, the top layer has a low salt content and is often times referred to as the upper convective zone (Lu and others, 2002). The bottom layer is a concentrated brine that is either convective or temperature stratified dependent on the surrounding environment. Solar insolation is absorbed and stored in the lower, denser brine while the overlying halocline acts as an insulating layer and prevents heat from moving upwards from the lower zone (Lu and others, 2002). In the case of the Tully Valley solar pond, water within the pond can be over 90 degrees Fahrenheit (°F) in late summer and early fall. The purpose of this report is to summarize observations at the Tully Valley brine-filled sinkhole and provide supplemental climate data which might affect the pond salinity gradients insolation (solar energy).

Field Performance of Inverter-Driven Heat Pumps in Cold Climates

Energy Technology Data Exchange (ETDEWEB)

Williamson, James [Consortium of Advanced Residential Buildings, Norwalk, CT (United States); Aldrich, Robb [Consortium of Advanced Residential Buildings, Norwalk, CT (United States)

2015-08-19

Traditionally, air-source heat pumps (ASHPs) have been used more often in warmer climates; however, some new ASHPs are gaining ground in colder areas. These systems operate at subzero (Fahrenheit) temperatures and many do not include backup electric resistance elements. There are still uncertainties, however, about capacity and efficiency in cold weather. Also, questions such as “how cold is too cold?” do not have clear answers. These uncertainties could lead to skepticism among homeowners; poor energy savings estimates; suboptimal system selection by heating, ventilating, and air-conditioning contractors; and inconsistent energy modeling. In an effort to better understand and characterize the heating performance of these units in cold climates, the U.S. Department of Energy Building America team, Consortium for Advanced Residential Buildings (CARB), monitored seven inverter-driven, ductless ASHPs across the Northeast. Operating data were collected for three Mitsubishi FE18 units, three Mitsubishi FE12 units, and one Fujitsu 15RLS2 unit. The intent of this research was to assess heat output, electricity consumption, and coefficients of performance (COPs) at various temperatures and load conditions. This assessment was accomplished with long- and short-term tests that measured power consumption; supply, return, and outdoor air temperatures; and airflow through the indoor fan coil.

Effects of Degree of Superheat on the Running Performance of an Organic Rankine Cycle (ORC Waste Heat Recovery System for Diesel Engines under Various Operating Conditions

Directory of Open Access Journals (Sweden)

Kai Yang

2014-04-01

Full Text Available This study analyzed the variation law of engine exhaust energy under various operating conditions to improve the thermal efficiency and fuel economy of diesel engines. An organic Rankine cycle (ORC waste heat recovery system with internal heat exchanger (IHE was designed to recover waste heat from the diesel engine exhaust. The zeotropic mixture R416A was used as the working fluid for the ORC. Three evaluation indexes were presented as follows: waste heat recovery efficiency (WHRE, engine thermal efficiency increasing ratio (ETEIR, and output energy density of working fluid (OEDWF. In terms of various operating conditions of the diesel engine, this study investigated the variation tendencies of the running performances of the ORC waste heat recovery system and the effects of the degree of superheat on the running performance of the ORC waste heat recovery system through theoretical calculations. The research findings showed that the net power output, WHRE, and ETEIR of the ORC waste heat recovery system reach their maxima when the degree of superheat is 40 K, engine speed is 2200 r/min, and engine torque is 1200 N·m. OEDWF gradually increases with the increase in the degree of superheat, which indicates that the required mass flow rate of R416A decreases for a certain net power output, thereby significantly decreasing the risk of environmental pollution.

Tensile properties of vanadium alloys irradiated at <430{degrees}C

Energy Technology Data Exchange (ETDEWEB)

Chung, H.M.; Smith, D.L. [Argonne National Lab., IL (United States)

1997-08-01

Recent attention to vanadium alloys has focused on significant susceptibility to loss of work-hardening capability in irradiation experiments at <430{degrees}C. An evaluation of this phenomenon was conducted on V-Ti, V-Cr-Ti, and V-Ti-Si alloys irradiated in several conventional and helium-charging irradiation experiments in the FFTF-MOTA, HFIR, and EBR-II. Work hardening capability and uniform tensile elongation appear to vary strongly from alloy and heat to heat. A strong heat-to-heat variation has been observed in V-4Cr-4Ti alloys tested, i.e., a 500-kg heat (No. 832665), a 100-kg heat (VX-8), and a 30-kg heat (BL-47). The significant differences in susceptibility to loss of work-hardening capability from one heat to another are estimated to correspond to a difference of {approx}100{degrees}C or more in minimum allowable operating temperature (e.g., 450 versus 350{degrees}C).

Heat buffers improve capacity and exploitation degree of geothermal energy sources

NARCIS (Netherlands)

Ooster, A.van t; Wit, J. de; Janssen, E.G.O.N.; Ruigrok, J.

2008-01-01

This research focuses on the role of heat buffers to support optimal use of combinations of traditional and renewable heat sources like geothermal heat for greenhouse heating. The objective was to determine the contribution of heat buffers to effective new combinations of resources that satisfy

High-heat-flux testing of helium-cooled heat exchangers for fusion applications

International Nuclear Information System (INIS)

Youchison, D.L.; Izenson, M.G.; Baxi, C.B.; Rosenfeld, J.H.

1996-01-01

High-heat-flux experiments on three types of helium-cooled divertor mock-ups were performed on the 30-kW electron beam test system and its associated helium flow loop at Sandia National Laboratories. A dispersion-strengthened copper alloy (DSCu) was used in the manufacture of all the mock-ups. The first heat exchanger provides for enhanced heat transfer at relatively low flow rates and much reduced pumping requirements. The Creare sample was tested to a maximum absorbed heat flux of 5.8 MW/m 2 . The second used low pressure drops and high mass flow rates to achieve good heat removal. The GA specimen was tested to a maximum absorbed heat flux of 9 MW/m 2 while maintaining a surface temperature below 400 degree C. A second experiment resulted in a maximum absorbed heat flux of 34 MW/m 2 and surface temperatures near 533 degree C. The third specimen was a DSCu, axial flow, helium-cooled divertor mock-up filled with a porous metal wick which effectively increases the available heat transfer area. Low mass flow and high pressure drop operation at 4.0 MPa were characteristic of this divertor module. It survived a maximum absorbed heat flux of 16 MW/m 2 and reached a surface temperature of 740 degree C. Thermacore also manufactured a follow-on, dual channel porous metal-type heat exchanger, which survived a maximum absorbed heat flux of 14 MW/m 2 and reached a maximum surface temperature of 690 degree C. 11refs., 20 figs., 3 tabs

Experimental investigation of a manifold heat-pipe heat exchanger

International Nuclear Information System (INIS)

Konev, S.V.; Wang Tszin' Lyan'; D'yakov, I.I.

1995-01-01

Results of experimental investigations of a heat exchanger on a manifold water heat pipe are given. An analysis is made of the temperature distribution along the heat-transfer agent path as a function of the transferred heat power. The influence of the degree of filling with the heat transfer agent on the operating characteristics of the construction is considered

76 FR 69198 - Proposed Establishment of the Middleburg Virginia Viticultural Area

Science.gov (United States)

2011-11-08

..., University of California Press, 1974, pp. 61-64). One degree day accumulates for each degree Fahrenheit that... John Leven Powell Returns to Middleburg,'' Audrey Windsor Bergner, Middleburg Press, 1995). Originally..., creeks, roads, elevation points, a national park boundary line, and other points shown on the USGS maps...

27 CFR 30.1 - Gauging of distilled spirits.

Science.gov (United States)

2010-04-01

... correcting hydrometer indications at temperatures between 0 and 100 degrees Fahrenheit to true proof. If distilled spirits contain dissolved solids, temperature correction of the hydrometer reading by the use of...

Influence of molecular weight and degree of substitution of various carboxymethyl celluloses on unheated and heated emulsion-type sausage models.

Science.gov (United States)

Gibis, Monika; Schuh, Valerie; Allard, Karin; Weiss, Jochen

2017-03-01

Four carboxymethyl celluloses (CMCs) differing in molecular weight (M W ) and degree of substitution (°DS) were initially characterized in NaCl solution (0.1 M) and on properties of emulsion-type sausage models. The impact of the different CMCs (0-2 wt%) on the rheological behavior and firmness of an emulsion-type sausage models containing 1.8wt% NaCl was studied. Rheology (unheated/heated) and firmness (heated) showed an increasing effect with increasing CMC concentrations. Addition of>1wt% CMC led to a decrease in storage modulus of the unheated/heated batter and to a decrease in firmness of heated independent of the CMC-type used. CLSM revealed that high amounts of CMCs prevented formation of a coherent protein matrix. Water-binding capacity indicated that CMC contributed to the water-retention capability of sausage batters. Small differences between the CMCs were observed using various °DS and similar M W. Results indicate that the addition of low CMC concentrations (≤0.5wt%) may help to reduce fat content. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of Stronger and More Reliable Cast Austenitic Stainless Steels (H-Series) Based on Scientific and Design Methodology

Energy Technology Data Exchange (ETDEWEB)

Pankiw, Roman I; Muralidharan, G. (Murali); Sikka, Vinod K.

2006-06-30

The goal of this project was to increase the high-temperature strength of the H-Series of cast austenitic stainless steels by 50% and the upper use temperature by 86 to 140 degrees fahrenheit (30 to 60 degrees celsius). Meeting this goal is expected to result in energy savings of 35 trillion Btu/year by 2020 and energy cost savings of approximately $230 million/year. The higher-strength H-Series cast stainless steels (HK and HP type) have applications for the production of ethylene in the chemical industry, for radiant burner tubes and transfer rolls for secondary processing of steel in the steel industry, and for many applications in the heat treating industry, including radiant burner tubes. The project was led by Duraloy Technologies, Inc., with research participation by Oak Ridge National Laboratory (ORNL) and industrial participation by a diverse group of companies.

Solar heating system

Science.gov (United States)

Schreyer, James M.; Dorsey, George F.

1982-01-01

An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

Numerical modeling of historical change of volcanic heat sources: Numerical modeling of heat and mass transport up to 1000 degree C; Kazansei netsugen no keiji henka no shumyureshon kaiseki: 1000 degree C madeno netsu{center{underscore}dot}ryutai shumyureshon kaiseki

Energy Technology Data Exchange (ETDEWEB)

Hanano, Mineyuki [JMC Geothermal Engineering Corp., Iwate (Japan)

1998-12-01

Temperature structure and its historical change around volcanos has been of interest for volcanology, geothermal development, etc. Magmatic intrusives have temperatures ranging from 700 to 850 degree C. Thus, there exists super-critical fluid around them. Numerical modeling of temperature changes around young volcanos and their heat sources thus requires treatment of the super-critical fluid. We describe one method for effective treatment of the super-critical fluid in the numerical modeling of porous media for the purpose of solving large-scale high-temperature problems of such phenomena. (author)

Climate Prediction Center(CPC)Monthly U.S. Selected Cities Temperature Summary

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Monthly U.S. reported temperature summaries in degrees Fahrenheit generated from the GTS metar(hourly) and synoptic(6-hourly)observations for selected cities based...

27 CFR 30.64 - Table 4, showing the fractional part of a gallon per pound at each percent and each tenth percent...

Science.gov (United States)

2010-04-01

... of the liquid and its apparent proof (hydrometer indication, corrected to 60 degrees Fahrenheit). The... of blended whisky containing added solids Temperature °F 75.0° Hydrometer reading 92.0° Apparent...

27 CFR 30.61 - Table 1, showing the true percent of proof spirit for any indication of the hydrometer at...

Science.gov (United States)

2010-04-01

... percent of proof spirit for any indication of the hydrometer at temperatures between zero and 100 degrees... true percent of proof spirit for any indication of the hydrometer at temperatures between zero and 100... hydrometer likely to occur in practice at temperatures between zero and 100 degrees Fahrenheit and shall be...

Induction of heat-shock proteins and phagocytic function of chicken macrophage following in vitro heat exposure

International Nuclear Information System (INIS)

Miller, L.; Qureshi, M.A.

1992-01-01

The protein profiles and phagocytic ability of Sephadex-elicited chicken peritoneal macrophages were examined following heat-shock exposure. Macrophage cultures were exposed to various temperatures, time exposures and recovery periods. Densitometric analysis of SDS-PAGE autoradiographs revealed that heat-induced macrophages synthesized three major (23, 70 and 90 kD) heat-shock proteins (HSPs). The optimal temperature and time for induction of these HSPs was 45-46 degrees C for 1 h, with a variable recovery period for each HSP. Macrophages exposed to 45 degrees C for 30 and 60 min were significantly depressed in phagocytosis of uncoated sheep erythrocytes (SE) under 45 degrees C incubation conditions. However, phagocytosis of antibody-coated SE was not affected when compared to 41 degrees C control cultures. Macrophages allowed to recover at 41 degrees C following heat-shock exhibited no alterations in their phagocytic ability for either antibody-coated or uncoated SE. This study suggests that heat shock induces three major HSPs in chicken peritoneal macrophages in addition to maintaining their Fc-mediated phagocytic function while significantly depressing their nonspecific phagocytosis

Cough Culprits: What's the Difference Between Bronchitis and Pneumonia?

Science.gov (United States)

... bronchitis, it is usually mild (below 101 degrees Fahrenheit). In more serious cases, you may have chest ... 20892-2094 nihnewsinhealth@od.nih.gov Tel: 301-451-8224 Editor: Harrison Wein, Ph.D. Managing Editor: ...

Climate Prediction Center (CPC) Weekly U.S. Selected Cities Temperature Summary

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Weekly U.S. reported temperature summaries in degrees Fahrenheit generated from the GTS metar(hourly) and synoptic(6-hourly)observations for selected cities based on...

Waste heat recovery system

International Nuclear Information System (INIS)

Phi Wah Tooi

2010-01-01

Full text: The Konzen in-house designed anaerobic digester system for the POME (Palm Oil Mill Effluent) treatment process is one of the registered Clean Development Mechanism (CDM) projects in Malaysia. It is an organic wastewater treatment process which achieves excellent co-benefits objectives through the prevention of water pollution and reduction of greenhouse gas emissions, which is estimated to be 40,000 to 50,000 t-CO 2 per year. The anaerobic digester was designed in mesophile mode with temperature ranging from 37 degree Celsius to 45 degree Celsius. A microorganisms growth is optimum under moderately warm temperature conditions. The operating temperature of the anaerobic digester needs to be maintained constantly. There are two waste heat recovery systems designed to make the treatment process self-sustaining. The heat recovered will be utilised as a clean energy source to heat up the anaerobic digester indirectly. The first design for the waste heat recovery system utilises heat generated from the flue gas of the biogas flaring system. A stainless steel water tank with an internal water layer is installed at the top level of the flare stack. The circulating water is heated by the methane enriched biogas combustion process. The second design utilizes heat generated during the compression process for the biogas compressor operation. The compressed biogas needs to be cooled before being recycled back into the digester tank for mixing purposes. Both the waste heat recovery systems use a design which applies a common water circulation loop and hot water tank to effectively become a closed loop. The hot water tank will perform both storage and temperature buffer functions. The hot water is then used to heat up recycled sludge from 30 degree Celsius to 45 degree Celsius with the maximum temperature setting at 50 degree Celsius. The recycled sludge line temperature will be measured and monitored by a temperature sensor and transmitter, which will activate the

Phase II Tungsten Fate-and Transport Study for Camp Edwards

Science.gov (United States)

2010-02-01

cubic meters degrees Fahrenheit (oF-32)/1.8 degrees Celsius (oC) feet 0.3048 meters gallons (U.S. liquid) 3.785412 E-03 liters inches 0.0254 meters...1 Desorption/dissolution of tungsten 451 39 8.1 2 Sorption of sodium tungstate and desorption/dissolution of tungsten and sodium tungstate 124

Climate Prediction Center(CPC) Monthly U.S. Precipitation and Temperature Summary

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Monthly U.S. minimum and maximum temperatures in whole degrees Fahrenheit and reported and estimated precipitation amounts in hundredths of inches(ex 100 is 1.00...

Climate Prediction Center(CPC)Daily U.S. Precipitation and Temperature Summary

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Daily U.S. minimum and maximum temperatures in whole degrees Fahrenheit and reported and estimated precipitation amounts in hundredths of inches(ex 100 is 1.00...

Aviation and the Environment: Aviation's Effects on the Global Atmosphere Are Potentially Significant and Expected to Grow

National Research Council Canada - National Science Library

2000-01-01

... to 1.4 degrees Fahrenheit over the last century. Many experts agree that, in total, greenhouse gases are warming the earth and that this warming could have harmful effects on the environment and human health...

Climate Prediction Center (CPC)Weekly U.S. Precipitation and Temperature Summary

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Weekly U.S. minimum and maximum temperatures in whole degrees Fahrenheit and reported and estimated precipitation amounts in hundredths of inches(ex 100 is 1.00...

10 CFR 431.2 - Definitions.

Science.gov (United States)

2010-01-01

... temperature of one pound of water by one degree Fahrenheit. Covered equipment means any electric motor, as... washer, as defined in § 431.152; distribution transformer, as defined in § 431.192; illuminated exit sign...

Cooling hyperthermic firefighters by immersing forearms and hands in 10 degrees C and 20 degrees C water.

Science.gov (United States)

Giesbrecht, Gordon G; Jamieson, Christopher; Cahill, Farrell

2007-06-01

Firefighters experience significant heat stress while working with heavy gear in a hot, humid environment. This study compared the cooling effectiveness of immersing the forearms and hands in 10 and 20 degrees C water. Six men (33 +/- 10 yr; 180 +/- 4 cm; 78 +/- 9 kg; 19 +/- 5% body fat) wore firefighter 'turn-out gear' (heavy clothing and breathing apparatus weighing 27 kg) in a protocol including three 20-min exercise bouts (step test, 78 W, 40 degrees C air, 40% RH) each followed by a 20-min rest/cooling (21 degrees C air); i.e., 60 min of exercise, 60 min of cooling. Turn-out gear was removed during rest/cooling periods and subjects either rested (Control), immersed their hands in 10 or 20 degrees C water (H-10, H-20), or immersed their hands and forearms in 10 or 20 degrees C water (HF-10, HF-20). In 20 degrees C water, hand immersion did not reduce core temperature compared with Control; however, including forearm immersion decreased core temperature below Control values after both the second and final exercise periods (p hand immersion produced a lower core temperature (0.8 degrees C above baseline) than all other conditions (1.1 to 1.4 degrees C above baseline) after the final exercise period (p Hand and forearm immersion in cool water is simple, reduces heat strain, and may increase work performance in a hot, humid environment. With 20 degrees C water, forearms should be immersed with the hands to be effective. At lower water temperatures, forearm and/or hand immersion will be effective, although forearm immersion will decrease core temperature further.

Microstructure of wood charcoal prepared by flash heating

NARCIS (Netherlands)

Kurosaki, F; Ishimaru, K; Hata, T; Bronsveld, P; Kobayashi, E; Imamura, Y

2003-01-01

Carbonized wood prepared by flash heating at 800 degreesC for I h shows a different microstructure and surface chemical structure than char formed after slow heating at 4 degreesC/min to 800 degreesC for I h. Flash heating produces pores that are surrounded by aggregates of carbon structures 25 to

Analysis of influence of change of office hours on degree of heating of isolation of puttee of anchor of electric motor of piston compressor

Directory of Open Access Journals (Sweden)

A.V. Mazur

2012-12-01

Full Text Available The article is devoted the question of research of factors which influence on changing of the mode of operations of electric motor of compressor, which in same queue influence on the degree of heating of isolation of winding of anchor ED.

Heat generated by knee prostheses.

Science.gov (United States)

Pritchett, James W

2006-01-01

Temperature sensors were placed in 50 knees in 25 patients who had one or both joints replaced. Temperature recordings were made before walking, after walking, and after cycling. The heat generated in healthy, arthritic, and replaced knees was measured. The knee replacements were done using eight different prostheses. A rotating hinge knee prosthesis generated a temperature increase of 7 degrees C in 20 minutes and 9 degrees C in 40 minutes. An unconstrained ceramic femoral prosthesis articulating with a polyethylene tibial prosthesis generated a temperature increase of 4 degrees C compared with a healthy resting knee. The other designs using a cobalt-chrome alloy and high-density polyethylene had temperature increases of 5 degrees-7 degrees C with exercise. Frictional heat generated in a prosthetic knee is not immediately dissipated and may result in wear, creep, and other degenerative processes in the high-density polyethylene. Extended periods of elevated temperature in joints may inhibit cell growth and perhaps contribute to adverse performance via bone resorption or component loosening. Prosthetic knees generate more heat with activity than healthy or arthritic knees. More-constrained knee prostheses generate more heat than less-constrained prostheses. A knee with a ceramic femoral component generates less heat than a knee with the same design using a cobalt-chromium alloy.

Diurnal variability of heat fluxes and heat content at a few locations off central east coast of India during April 1989

Digital Repository Service at National Institute of Oceanography (India)

Sadhuram, Y.; Rao, B.P.; Rao, V.S.; Rao, T.V.N.

Diurnal variability of surface wind speed, net heat exchange, sea surface temperature, vertical thermal structure and heat content at three locations, viz., station A (17 degrees 59'N, 83 degrees 53.9'E), station B (17 degrees 00'N, 82 degrees 32...

Effect of Crystallisation Degree on Hardness of Basaltic Glass-Ceramics

DEFF Research Database (Denmark)

Jensen, Martin; Smedskjær, Morten Mattrup; Yue, Yuanzheng

The dependence of hardness of basaltic glass-ceramics on their crystallisation degree has been explored by means of differential scanning calorimetry, optical microscopy, X-ray diffraction, and Vickers indentation. Different degrees of crystallisation in the basaltic glasses have been obtained...... by varying the temperature of heat treatment. The change of the relative degree of crystallisation with the heat treatment temperature can be described by an empirical model established in this work. The predominant crystalline phase in the glass has been identified as the pyroxene augite. The hardness...... principle calculations. It is found that the hardness of the glass phase decreases slightly with an increase in the degree of crystallisation, while that of the augite phase drastically decreases....

The contact heat transfer between the heating plate and granular materials in rotary heat exchanger under overloaded condition

Directory of Open Access Journals (Sweden)

Luanfang Duan

2018-03-01

Full Text Available In the present work, the contact heat transfer between the granular materials and heating plates inside plate rotary heat exchanger (PRHE was investigated. The heat transfer coefficient is dominated by the contact heat transfer coefficient at hot wall surface of the heating plates and the heat penetration inside the solid bed. A plot scale PRHE with a diameter of Do = 273 mm and a length of L = 1000 mm has been established. Quartz sand with dp = 2 mm was employed as the experimental material. The operational parameters were in the range of ω = 1 – 8 rpm, and F = 15, 20, 25, 30%, and the effect of these parameters on the time-average contact heat transfer coefficient was analyzed. The time-average contact heat transfer coefficient increases with the increase of rotary speed, but decreases with the increase of the filling degree. The measured data of time-average heat transfer coefficients were compared with theoretical calculations from Schlünder’s model, a good agreement between the measurements and the model could be achieved, especially at a lower rotary speed and filling degree level. The maximum deviation between the calculated data and the experimental data is approximate 10%. Keywords: Rotary heat exchanger, Contact heat transfer, Granular material, Heating plate, Overloaded

Antarctic Camps Snow Drift Management Handbook

Science.gov (United States)

2014-09-01

To Obtain degrees (angle) 0.01745329 radians degrees Fahrenheit (F-32)/1.8 degrees Celsius feet 0.3048 meters inches 0.0254 meters knots 0.5144444...982 1095 1213 2.8 1.56 308 373 444 521 605 694 790 891 999 1114 1234 3.0 1.67 313 379 451 530 614 705 802 906 1015 1131 1254 3.2 1.76 318 385 458

Validation of degree heating weeks as a coral bleaching index in the northwestern Pacific

Science.gov (United States)

Kayanne, Hajime

2017-03-01

Mass bleaching is the most significant threat to coral reefs. The United States National Oceanic and Atmospheric Administration monitors world sea surface temperature (SST) and releases warnings for bleaching based on degree heating weeks (DHW), which is the accumulation of temperature anomalies exceeding the monthly maximum mean SST for a given region. DHW values >4.0 °C-weeks are thought to induce bleaching, and those >8.0 °C-weeks are thought to result in widespread bleaching and some mortality. This study validates the effectiveness of DHW as a mass bleaching index by on-site historical observation at eight sites in the northwestern Pacific Ocean. The mass bleaching events occurred during different years at different sites. The recorded years of the bleaching events matched well with DHW values >8 °C-weeks, and the logistically projected probability of bleaching against DHW showed a positive relationship. DHW provides a reasonable threshold for bleaching.

PALAVRA E MEMÓRIA NOS HOMENS-LIVROS DE FAHRENHEIT 451: A LITERATURA DE FICÇÃO CIENTÍFICA E A CONTEMPLAÇÃO DAS RUÍNAS DO FUTURO

Directory of Open Access Journals (Sweden)

Marília Flores Seixas de Oliveira

2009-01-01

Full Text Available This paper discusses the possible heuristic effects of reading dystopian literary texts and its reflective critical dimension due to modern sociability and its views of the future. It analyses the importance of reading and literature in the development of a critical awareness that will promote changes and ethic behaviors as opposed to alienation and submission to modernity, observed in the metaphor of the “book-men” in the novel Fahrenheit 451 by Ray Bradbury. It addresses theoretical aspects of the speculative literature of science fiction by anchoring on postulations of esthetic reception and proposing, as an analytical road for these texts, the valorization of the diegetic content, the perlocutory dimension, the emphasis on meaning and on text as symbolic form, and the interdisciplinary perception which is activated through the reading process and the construction of the “memories of the future”.

Heat transfer coefficient in pool boiling for an electrically heated tube at various inclinations

International Nuclear Information System (INIS)

Fahmy, A.S.A.; Mariy, A.H.; Mahmoud, S.I.; Ibrahim, N.A.

1987-01-01

An experimental investigation is carried out study the behaviour of heat transfer in pool boiling from a vertical and inclined heated tube at atmospheric pressure. An imperial correlation joining the different parameters affecting the heat transfer coefficient in pool boiling for an electrically heated tube at various inclinations is developed. Two test sections (zircaloy-4 and stainless steel) of 16 n n outer diameter and 120 nm length are investigated. Four levels of heat flux are used for heating the two lest sections (e.g. 381, 518, 721 and 929 k.watt/n 2). The maximum surface temperature achieved is 146.5 degree c for both materials, and the maximum bulk temperature is 95 degree C. It is found that the average heat transfer coefficient is inversely proportional with heated length l, where it reaches a constant value in the horizontal position. The heat transfer coefficient curves at various inclinations with respect to the heated tube length pass around one point which is defined as limit length

Three story residence with solar heat--Manchester, New Hampshire

Science.gov (United States)

1981-01-01

When heat lost through ducts is counted for accurate performance assessment, solar energy supplied 56 percent of building's space heating load. Average outdoor temperature was 53 degrees F; average indoor temperature was 69 degrees F. System operating modes included heating from solar collectors, storing heat, heating from storage, auxiliary heating with oil fired furnace, summer venting, and hot water preheating.

Linking long-range weather forecasts and heat consumption as a determining factor when buying fuel chips for town heating plants

International Nuclear Information System (INIS)

Rolev, A.-M.

1991-12-01

The aim of this study is to test whether long-range weather forecasts from the meteorological services can be used as a determining factor when buying fuel chips. In the study the fuel consumption of heating plants and the factors determining the monthly consumption are mentioned. Degree-day statistics in Denmark for the last 30 years are explained as well as the difficulties in conjunction with the prediction of long-range weather conditions. This study compares degree days in 1989-1990 month by month with the actual and theoretic chip consumption in three different heating plants the same year. The theoretic chip consumption is calculated on the basis of degree days in a ''standard year'' and the annual chip consumption of the heating plant, among other things. Furthermore, on the basis of degree-day statistics the report makes it possible to estimate the monthly chip consumption of a heating plant in a ''standard year'', in an extremely cold year (maximum degree days), and in an extremely warm year (minimum degree days). However, not everything can be predicted, and it is not yet possible to predict reliable weather forecasts for more than 5 days ahead. The study concludes that long-range weather forecasts cannot be used as a determining factor when buying fuel chips for heating plants. When buying fuel chips one must still use statistics and degree days, supplimented by figures based on experience from actual chip consumption in the individual heating plant. These figures take into consideration the different types of heating plants, as well as heat supply, chip-supplier, storing facilities, other fuels, etc. (au)

Clinical observation on thermophysics in radiofrequency heating

International Nuclear Information System (INIS)

Qi Chao; Li Dingjiu; Guo Baozhong; Shi Yonggang; Yang Daoke

2002-01-01

Objective: To study the physical characters of NRL-001 heating machine. Methods: 151 patients with deep-seated tumors were heated by NRL-001 heating machine in the recent one year. NRL-001 heating machine with two pairs of perpendicular electrodes intercross the two magnetic fields at the center. thermocouples were placed in rectum, ear, esophageal lumen, tumor mass and peritoneal cavity for temperature measurement. The accuracy of the measurement system was evaluated by comparing the rectal mercury thermometer reading with the machine measured value right after the completion of heating. Results: The deviation between the values read by rectal mercury thermometer and the machine was 0.1-0.7 degree C. Intra-tumoral measurement in a patient with lung carcinoma revealed that the temperature within the tumor was 2.0 degree C higher than that in the esophagus. When the peritoneal cavity was heated after perfusion with hot normal saline, the temperature in peritoneal cavity was 0.5 degree C higher than that in the rectum which became even with heating time. Temperature homogeneity was obtained after 50 minutes and abdominal massage was able to shorten this interval. Conclusions: The temperature measurement system of NRL-001 heating machine, having acceptable discrepancies from the mercury thermometer, is reliable. The temperature in the ear, esophagus and rectum can be trusted when treating esophageal or peritoneo-pelvic lesions. Temperature in the esophagus is 2.0 degree C lower than that in lung tumor. Temperature measured in the heated region is about 2.0 degree C higher than that over the whole body. Intra-tumoral temperature measurement is highly recommended if possible. Peritoneo-pelvic heating after peritoneal perfusion is feasible, with the temperature homogeneity obtained as heating time is prolonged, thereby heating time over 120 min is recommended. Temperature measurement is, in fact, necessary for every session of hyperthermia

Calorimetric determination of the heat of precipitation of pseudoephedrine racemic compound--its agreement with the heat of solution.

Science.gov (United States)

Pudipeddi, M; Sokoloski, T D; Duddu, S P; Carstensen, J T

1995-10-01

The heat of precipitation of dl-pseudoephedrine was determined by direct calorimetry using a Tronac isoperibolic calorimeter. The precipitation of dl-pseudoephedrine was induced by mixing aqueous solutions of the two enantiomers, namely, d- and l-pseudoephedrine, directly in the calorimeter. The molar heat of precipitation of dl-pseudoephedrine was -2.7 and -3.0 kcal/mol at 25 and 30 degrees C, respectively. The aqueous solubility of dl-pseudoephedrine was determined over a temperature range of 20-40 degrees C. The van't Hoff solubility plot was nonlinear. The apparent heat of solution at saturation was obtained from the solubility data using a nonlinear regression model. A good agreement between the magnitude of the apparent heat of solution at saturation and the heat of precipitation was noticed at both 25 and 30 degrees C.

Solar energy system performance evaluation: Seasonal report for IBM system 1A, Huntsville, Alabama

Science.gov (United States)

1980-01-01

The operational and thermal performance of the solar energy system, Sims Prototype System 1A, is described. The system was designed by IBM to provide 50 to 60 percent of the space heating and domestic hot water preheating load to a 2,000 square foot floor space single family residence in the Huntsville area. The load design temperature inside the building was to be maintained at 70 degrees fahrenheit with auxiliary energy for heating supplied by an electric heat pump assisted by an electric resistance strip heater. In general the disappointing operation of this system is attributed to the manner in which it was used. The system was designed for residential application and used to satisfy the demands of an office environment. The differences were: (1) inside temperature was not maintained at 70 F as expected; and (2) hot water usage was much lower than expected. The conclusion is that the solar energy system must be designed for the type of application in which it is used. Misapplication usually will have an adverse affect on system performance.

Indoor temperatures for calculating room heat loss and heating capacity of radiant heating systems combined with mechanical ventilation systems

DEFF Research Database (Denmark)

Wu, Xiaozhou; Olesen, Bjarne W.; Fang, Lei

2016-01-01

change rates on the indoor temperatures were performed using the proposed model. When heated surface temperatures and air change rates were from 21.0 to 29.0 degrees C and from 0.5 to 4.0 h-1, the indoor temperatures for calculating the transmission heat loss and ventilation heat loss were between 20...

Organic Perfluorohalogenate Salts; New Energetic Materials

Science.gov (United States)

2014-06-01

thermochemical) calorie (thermochemical) cal (thermochemical/cm 2 ) curie degree (angle) degree Fahrenheit electron volt erg erg/second foot foot-pound...3IF5 674 (10) 635 (0+) 620 (10) 599 sh 593 (5.3) 585 sh 568 (0+) 554 sh 557 (0+) 543 (3.0) 527 (2) 502 sh 451 (0.3) 391 (0.5) 382 (0.5) 367 (0.3) 347 (0

27 CFR 30.51 - Procedures for measurement of bulk spirits.

Science.gov (United States)

2010-04-01

... AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS GAUGING MANUAL Gauging Procedures Determination... persons qualified to calibrate such conveyances. Volumetric measurements in tanks shall be made only in... standard of 60 degrees Fahrenheit, gallonage determined by volumetric measurements shall be corrected to...

Characteristic of 120 degree C thermoluminescence peak of iceland spar

International Nuclear Information System (INIS)

Lu Xinwei; Han Jia

2006-01-01

The basic characteristic of 120 degree C thermoluminescence peak of iceland spar was studied. The experimental result indicates the longevity of 120 degree C thermoluminescence peak of iceland spar is about 2 h under 30 degree C. The thermoluminescence peak moves to the high temperature when the heating speed increasing. The intensity of 120 degree C thermoluminescence peak of iceland spar is directly proportional to radiation dose under 15 Gy. (authors)

The creation of cooling degree (CDD) and heating degree day (HDD) climatic maps for South Africa

CSIR Research Space (South Africa)

Conradie, Dirk CU

2015-12-01

Full Text Available that could better support adaptive building design decisions in creating comfortable thermal environments. Over the last 100 years, many different heat strain indices have been proposed to indicate comparative thermal comfort levels. After reviewing...

78 FR 52172 - Don W. Gilbert Hydro Power, LLC; Notice of Availability of Environmental Assessment

Science.gov (United States)

2013-08-22

... character of the area would reduce visual effects. Avoiding reflective materials and highly-contrasting... stated that the proposed project would not affect any of its trust species (email communication on March... an average low of 10.2 degrees Fahrenheit in January to an [[Page 52180

Promoting International Energy Security. Volume 1: Understanding Potential Air Force Roles

Science.gov (United States)

2012-01-01

obtain additional information, contact Distribution Services: Telephone: (310) 451 -7002; Fax: (310) 451 -6915; Email: order@rand.org Library of...raise the temperature of one pound of water one degree Fahrenheit ) DoD Department of Defense EIA U.S. Energy Information Administration IEA International

77 FR 50465 - Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania...

Science.gov (United States)

2012-08-21

...- 795, and the American Petroleum Institute (API) 5L specifications and meeting the physical parameters... 1000 degrees Fahrenheit, at various American Society of Mechanical Engineers (ASME) code stress levels..., line, and pressure pipes and redraw hollows produced, or equivalent, to the American Society for...

Fluidized-Bed Heat Transfer Modeling for the Development of Particle/Supercritical-CO2 Heat Exchanger

Energy Technology Data Exchange (ETDEWEB)

Ma, Zhiwen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Martinek, Janna G [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-06-03

Concentrating solar power (CSP) technology is moving toward high-temperature and high-performance design. One technology approach is to explore high-temperature heat-transfer fluids and storage, integrated with a high-efficiency power cycle such as the supercritical carbon dioxide (s-CO2) Brayton power cycle. The s-CO2 Brayton power system has great potential to enable the future CSP system to achieve high solar-to-electricity conversion efficiency and to reduce the cost of power generation. Solid particles have been proposed as a possible high-temperature heat-transfer medium that is inexpensive and stable at high temperatures above 1,000 degrees C. The particle/heat exchanger provides a connection between the particles and s-CO2 fluid in the emerging s-CO2 power cycles in order to meet CSP power-cycle performance targets of 50% thermal-to-electric efficiency, and dry cooling at an ambient temperature of 40 degrees C. The development goals for a particle/s-CO2 heat exchanger are to heat s-CO2 to =720 degrees C and to use direct thermal storage with low-cost, stable solid particles. This paper presents heat-transfer modeling to inform the particle/s-CO2 heat-exchanger design and assess design tradeoffs. The heat-transfer process was modeled based on a particle/s-CO2 counterflow configuration. Empirical heat-transfer correlations for the fluidized bed and s-CO2 were used in calculating the heat-transfer area and optimizing the tube layout. A 2-D computational fluid-dynamics simulation was applied for particle distribution and fluidization characterization. The operating conditions were studied from the heat-transfer analysis, and cost was estimated from the sizing of the heat exchanger. The paper shows the path in achieving the cost and performance objectives for a heat-exchanger design.

[Heat stroke and burns resulting from use of sauna

DEFF Research Database (Denmark)

Runitz, K.; Jensen, T.H.

2009-01-01

We describe a case of severe heat stroke resulting from exposure to extreme heat in a sauna for an unknown period of time. The patient sustained 20% 2nd degree burns. On arrival at the emergency department, the patient's temperature was 40.5 degrees C. At the critical care unit, the patient devel...... developed severe multi-organ failure and critical polyneuropathy. Severe heat stroke is a rare diagnosis in Denmark. The treatment is symptomatic and the prognosis is grave, especially in combination with severe burns Udgivelsesdato: 2009/1/26......We describe a case of severe heat stroke resulting from exposure to extreme heat in a sauna for an unknown period of time. The patient sustained 20% 2nd degree burns. On arrival at the emergency department, the patient's temperature was 40.5 degrees C. At the critical care unit, the patient...

Measurement of heat transfer effectiveness during collision of a Leidenfrost droplet with a heated wall - 15447

International Nuclear Information System (INIS)

Park, J.S.; Kim, H.; Bae, S.W.; Kim, K.D.

2015-01-01

Droplet-wall collision heat transfer during dispersed flow film boiling plays a role in predicting cooling rate and peak cladding temperature of overheated fuels during reflood following a LOCA accident in nuclear power plants. This study aims at experimentally studying effects of collision velocity and angle, as dynamic characteristics of the colliding droplet, on heat transfer. The experiments were performed by varying collision velocity from 0.2 to 1.5 m/s and collision angle between the droplet path and the wall in the range from 30 to 90 degrees under atmosphere condition. A single droplet was impinged on an infrared-opaque Pt film deposited on an infrared-transparent sapphire plate, which combination permits to measure temperature distribution of the collision surface using a high-speed infrared camera from below. The instantaneous local surface heat flux was obtained by solving transient heat conduction equation for the heated substrate using the measured surface temperature data as the boundary condition of the collision surface. Total heat transfer amount of a single droplet collision was calculated by integrating the local heat flux distribution on the effective heat transfer area during the collision time. The obtained results confirmed the finding from the previous studies that with increasing collision velocity, the heat transfer effectiveness increases due to the increase of the heat transfer area and the local heat flux value. Interestingly, it was found that as collision angle of a droplet with a constant collision velocity decreases from 90 to 50 degrees and thus the vertical velocity component of the collision decreases, the total heat transfer amount per a collision increases. It was observed that the droplet colliding with an angle less than 90 degrees slides on the surface during the collision and the resulting collision area is larger than that in the normal collision. On the other hand, further decrease of collision angle below 40 degrees

Melas Chasma, Day and Night.

Science.gov (United States)

2002-01-01

This image is a mosaic of day and night infrared images of Melas Chasma taken by the camera system on NASA's Mars Odyssey spacecraft. The daytime temperature images are shown in black and white, superimposed on the martian topography. A single nighttime temperature image is superimposed in color. The daytime temperatures range from approximately -35 degrees Celsius (-31 degrees Fahrenheit) in black to -5 degrees Celsius (23 degrees Fahrenheit) in white. Overlapping landslides and individual layers in the walls of Melas Chasma can be seen in this image. The landslides flowed over 100 kilometers (62 miles) across the floor of Melas Chasma, producing deposits with ridges and grooves of alternating warm and cold materials that can still be seen. The temperature differences in the daytime images are due primarily to lighting effects, where sunlit slopes are warm (bright) and shadowed slopes are cool (dark). The nighttime temperature differences are due to differences in the abundance of rocky materials that retain their heat at night and stay relatively warm (red). Fine grained dust and sand (blue) cools off more rapidly at night. These images were acquired using the thermal infrared imaging system infrared Band 9, centered at 12.6 micrometers.Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the 2001 Mars Odyssey mission for NASA's Office of Space Science in Washington, D.C. Investigators at Arizona State University in Tempe, the University of Arizona in Tucson and NASA's Johnson Space Center, Houston, operate the science instruments. Additional science partners are located at the Russian Aviation and Space Agency and at Los Alamos National Laboratories, New Mexico. Lockheed Martin Astronautics, Denver, is the prime contractor for the project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL. Aviation and Space Agency and at Los Alamos National Laboratories

Final Environmental Assessment/Overseas Environmental Assessment for Flight Experiment 1 (FE-1)

Science.gov (United States)

2017-08-01

Tourism , 2008). The global annual temperature has increased at an average rate of 0.07 degrees(°) Celsius [C] (0.13° Fahrenheit [Fl) per decade...of Business, Economic Development & Tourism , Office of Planning, "Hawai’ i Coastal Zone Management (CZM) Program Federal Consistency Concurrence

The Building America Indoor Temperature and Humidity Measurement Protocol

Energy Technology Data Exchange (ETDEWEB)

Metzger, C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Norton, Paul [Norton Energy Research & Development, Boulder, CO (United States)

2014-02-01

When modeling homes using simulation tools, the heating and cooling set points can have a significant impact on home energy use. Every four years, the Energy Information Administration (EIA) Residential Energy Consumption Survey (RECS) asks homeowners about their heating and cooling set points. Unfortunately, no temperature data is measured, and most of the time, the homeowner may be guessing at this number. Even one degree Fahrenheit difference in heating set point can make a 5% difference in heating energy use! So, the survey-based RECS data cannot be used as the definitive reference for the set point for the "average occupant" in simulations. The purpose of this document is to develop a protocol for collecting consistent data for heating/cooling set points and relative humidity so that an average set point can be determined for asset energy models in residential buildings. This document covers the decision making process for researchers to determine how many sensors should be placed in each home, where to put those sensors, and what kind of asset data should be taken while they are in the home. The authors attempted to design the protocols to maximize the value of this study and minimize the resources required to achieve that value.

Building America Indoor Temperature and Humidity Measurement Protocol

Energy Technology Data Exchange (ETDEWEB)

Engebrecht-Metzger, Cheryn [National Renewable Energy Lab. (NREL), Golden, CO (United States); Norton, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2014-02-01

When modeling homes using simulation tools, the heating and cooling set points can have a significant impact on home energy use. Every 4 years the Energy Information Administration (EIA) Residential Energy Consumption Survey (RECS) asks homeowners about their heating and cooling set points. Unfortunately, no temperature data is measured, and most of the time, the homeowner may be guessing at this number. Even one degree Fahrenheit difference in heating set point can make a 5% difference in heating energy use! So, the survey-based RECS data cannot be used as the definitive reference for the set point for the 'average occupant' in simulations. The purpose of this document is to develop a protocol for collecting consistent data for heating/cooling set points and relative humidity so that an average set point can be determined for asset energy models in residential buildings. This document covers the decision making process for researchers to determine how many sensors should be placed in each home, where to put those sensors, and what kind of asset data should be taken while they are in the home. The authors attempted to design the protocols to maximize the value of this study and minimize the resources required to achieve that value.

Temperature distribution of the energy consumed as heat in Canada

International Nuclear Information System (INIS)

Puttagunta, V.R.

1974-10-01

The amount of energy consumed as heat (excluding thermal generation of electricity) in Canada is estimated from statistical data available on the total consumption of energy for the years 1958 to 2000. Based on some actual plant data and other statistical information this energy consumption is sub-divided into four temperature categories: high (>260 degrees C), intermediate (140-260 degrees C), low (100-140 degrees C), and space heating (<100 degrees C). The results of this analysis show that approximately half of all the energy consumed in Canada has an end use as heat. Less than 10 percent of the energy consumed as heat is in the high temperature category, 12 to 14 percent is in the intermediate temperature range, 21 to 27 percent is in the low temperature range, and 50 to 58 percent is used for space heating. Over 90 percent of the energy consumed as heat in Canada is within the temperature capability of the CANDU-PHW reactor. (author)

Heat pump using dual heat sources of air and water. Performance with heat sources arranged in parallel; Mizu kuki ryonetsugen heat pump no kenkyu. Netsugen heiretsu unten ni okeru seino

Energy Technology Data Exchange (ETDEWEB)

Ito, S; Miura, N; Sato, S [Kanagawa Institute of Technology, Kanagawa (Japan); Uchikawa, Y; Hamada, K [Kubota Corp., Osaka (Japan)

1996-10-27

A heat pump system using water and air as heat sources was built and evaluated for its performance. In this system, evaporators may be operated singly or as connected in parallel or series, and, for each case, the quantity of heat acquired may be measured and system performance may be quantitatively evaluated. The findings follow. When the two heat sources are equal in temperature in the single-evaporator operation, the evaporation temperature is about 7{degree}C higher on the water side than on the air side, and the performance coefficient is about 0.7 higher. When the air heat source temperature is 25{degree}C in the parallel operation, like quantities of heat are obtained from both heat sources, and collection of heat from the water increases with a decrease in the air heat source temperature but, with an increase, collection from the air increases. When the air heat source temperature decreases, the evaporation temperature decreases in the single-evaporator working on the air and in the parallel operation but it levels off in the single-evaporator working on the water alone. When the water heat source temperature decreases, evaporation temperature drop is sharper in the single-evaporator working on the water than in the parallel operation, which suggests the transfer from the parallel operation to the single-evaporator working on the air. In the single-evaporator operation on the water heat source, the evaporation temperature linearly decreases with an increase in superheating. 1 ref., 10 figs.

Direct Heat

Energy Technology Data Exchange (ETDEWEB)

Lienau, P J

1990-01-01

Potential resources and applications of earth heat in the form of geothermal energy are large. United States direct uses amount to 2,100 MWt thermal and worldwide 8,850 MWt above a reference temperature of 35 degrees Celsius. Space and district heating are the major direct uses of geothermal energy. Equipment employed in direct use projects is of standard manufacture and includes downhole and circulation pumps, transmission and distribution pipelines, heat exchangers and convectors, heat pumps and chillers. Direct uses of earth heat discussed are space and district heating, greenhouse heating and fish farming, process and industrial applications. The economic feasibility of direct use projects is governed by site specific factors such as location of user and resource, resource quality, system load factor and load density, as well as financing. Examples are presented of district heating in Klamath Falls, and Elko. Further developments of direct uses of geothermal energy will depend on matching user needs to the resource, and improving load factors and load density.

49 CFR 173.32 - Requirements for the use of portable tanks.

Science.gov (United States)

2010-10-01

... that is significantly reflective, such as a light-reflecting color if painted, or a bright reflective... thickness that the overall thermal conductance is not more than 0.080 Btu per hour per square foot per... square foot per degree Fahrenheit differential in temperature per hour. The conductance must be...

76 FR 68511 - STP Nuclear Operating Company; South Texas Project, Units 1 and 2; Exemption

Science.gov (United States)

2011-11-04

... 21, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML103630408), requested an exemption from 10 CFR 50.46, ``Acceptance criteria for emergency core cooling systems [(ECCS... acceptable retention of post-quench ductility up to the 10 CFR 50.46 limits of 2200 degrees Fahrenheit and 17...

Heat conduction analysis of multi-layered FGMs considering the finite heat wave speed

International Nuclear Information System (INIS)

Rahideh, H.; Malekzadeh, P.; Golbahar Haghighi, M.R.

2012-01-01

Highlights: ► Using a layerwise-incremental differential quadrature for heat transfer of FGMs. ► Superior accuracy with fewer degrees of freedom of the method with respect to FEM. ► Considering multi-layered functionally graded materials. ► Hyperbolic heat transfer analysis of thermal system with heat generation. ► Showing the effect of heat wave speed on thermal characteristic of the system. - Abstract: In this work, the heat conduction with finite wave heat speed of multi-layered domain made of functionally graded materials (FGMs) subjected to heat generation is simulated. For this purpose, the domain is divided into a set of mathematical layers, the number of which can be equal or greater than those of the physical layers. Then, in each mathematical layer, the non-Fourier heat transfer equations are employed. Since, the governing equations have variable coefficients due to FGM properties, as an efficient and accurate method the differential quadrature method (DQM) is adopted to discretize both spatial and temporal domains in each layer. This results in superior accuracy with fewer degrees of freedom than conventional finite element method (FEM). To verify this advantages through some comparison studies, a finite element solution are also obtained. After demonstrating the convergence and accuracy of the method, the effects of heat wave speed for two different set of boundary conditions on the temperature distribution and heat flux of the domain are studied.

The study of the heat-engineering characteristics of a solar heat collector based on aluminum heat pipes

International Nuclear Information System (INIS)

Khairnasov, S.M.; Zaripov, V.K.; Passamakin, B.M. et al.

2013-01-01

This paper presents the results of studies into the heat-engineering characteristics of a flat heat solar collector based on aluminum heat pipes that is designed to be used in building facades. The principle of work and the structure of the solar collector are considered; the results of its comparison with a traditional flat solar collector are presented. The studies were performed at a heat carrier temperature range of +10 - +30 degree C and at a solar heat flow density of 400 - 1000 W/m 2 . The obtained experimental heat-engineering characteristics of the collector based on heat pipes show that they are at a level of traditional flow solar collectors; for example, its efficiency is 0.65 - 0.73. Meanwhile, the hydraulic resistance of the structure with heat pipes is by a factor of 2 - 2.4 smaller and ensures a high level of scalability, reliability, and maintainability, which is important when using it as an element of facade constructions of solar heat systems. (author)

Self-heating, gamma heating and heat loss effects on resistance temperature detector (RTD) accuracy

International Nuclear Information System (INIS)

Qian, T.; Hinds, H.W.; Tonner, P.

1997-01-01

Resistance temperature detectors (RTDs) are extensively used in CANDU nuclear power stations for measuring various process and equipment temperatures. Accuracy of measurement is an important performance parameter of RTDs and has great impact on the thermal power efficiency and safety of the plant. There are a number of factors that contribute to some extent to RTD measurement error. Self-heating, gamma heating and the heat-loss throughout conduction of the thermowell are three of these factors. The degree to which these three affect accuracy of RTDs used for the measurement of reactor inlet header temperature (RIHT) has been analyzed and is presented in this paper. (author)

Acoustic Levitator With Furnace And Laser Heating

Science.gov (United States)

Barmatz, Martin B.; Stoneburner, James D.

1991-01-01

Acoustic-levitation apparatus incorporates electrical-resistance furnace for uniform heating up to temperature of about 1,000 degrees C. Additional local heating by pair of laser beams raise temperature of sample to more than 1,500 degrees C. High temperature single-mode acoustic levitator generates cylindrical-mode accoustic resonance levitating sample. Levitation chamber enclosed in electrical-resistance furnace. Infrared beams from Nd:YAG laser provide additional local heating of sample. Designed for use in containerless processing of materials in microgravity or in normal Earth gravity.

10 CFR 455.2 - Definitions.

Science.gov (United States)

2010-01-01

... ENERGY ENERGY CONSERVATION GRANT PROGRAMS FOR SCHOOLS AND HOSPITALS AND BUILDINGS OWNED BY UNITS OF LOCAL... buildings on a contiguous site such as a school or college campus or multibuilding hospital. Construction... Fahrenheit degrees of each day's mean temperature above 65° for a given locality. Coordinating agency means a...

Reference Guide for Building Diagnostics Equipment and Techniques

Science.gov (United States)

1989-07-01

imaging systems, can be cali- 6155 El Camino Real, Carlsbad, Calif. 92008, (619) brated in temperature and radiosity . 931-3617; FUR Systems Inc., 16505...of microproces- or ctigital) in degrees Celsius or Fahrenheit or a sor technology, state-of-the-art optical and sight- radiosity display in Btu/ft2

Heat exchanges in coarsening systems

Energy Technology Data Exchange (ETDEWEB)

Corberi, Federico [Dipartimento di Fisica ' E R Caianiello' , Università di Salerno, via Ponte don Melillo, 84084 Fisciano (Italy); Gonnella, Giuseppe; Piscitelli, Antonio [Dipartimento di Fisica, Università di Bari and Istituto Nazionale di Fisica Nucleare, Sezione di Bari, via Amendola 173, 70126 Bari (Italy)

2011-10-15

This paper is a contribution to the understanding of the thermal properties of ageing systems where statistically independent degrees of freedom with greatly separated time scales are expected to coexist. Focusing on the prototypical case of quenched ferromagnets, where fast and slow modes can be respectively associated with fluctuations in the bulk of the coarsening domains and in their interfaces, we perform a set of numerical experiments specifically designed to compute the heat exchanges between different degrees of freedom. Our studies promote a scenario with fast modes acting as an equilibrium reservoir to which interfaces may release heat through a mechanism that allows fast and slow degrees to maintain their statistical properties independently.

Elevated-temperature tensile properties of three heats of commercially heat-treated Alloy 718

International Nuclear Information System (INIS)

Booker, M.K.; Booker, B.L.P.

1980-03-01

Three heats of commercially heat-treated alloy 718 were tensile tested over the temperature range from room temperature to 816 degree C and at nominal strain rates from 6.7 x 10 -6 to 6.7 x 10 -3 /s. We examined data for yield strength, ultimate tensile strength, uniform elongation, total elongation, and reduction in area and also inspected tensile stress-strain behavior. Yield and ultimate tensile strengths for commercially heat-treated alloy 718 decrease very gradually with temperature from room temperature up to about 600 degree C for a strain rate of 6.7 x 10 -5 /s or to about 700 degree C for a strain rate of 6.7 x 10 -4 /s. Above these temperatures the strength drops off fairly rapidly. Reduction in area and total elongation data show minimum around 700 degree C, with each ductility measure falling to 10% or less at the minimum. This minimum is more pranced and occurs at lower temperatures as strain rate decreases. Up to about 600 degree C the ductility is typically around 30%. As the temperature reaches 816 degree C the ductility again increases to perhaps 60%. The uniform elongation (plastic strain at peak load) decreases only slightly with temperature to about 500 degree C then drops off rapidly and monotonically with temperature, reaching values less than 1% at 816 degree C. At the highest test temperatures the load maximum may result, not from necking of the specimen, but from overaging of the precipitation-hardened microstructure. Stress-strain curves showed serrated deformations in the temperature range from 316 to 649 degree C, although they occur only for the faster strain rates at the supper end of this temperature range. The serrations can be quite large, involving load drops of perhaps 40 to 80 MPa. The serrations typically begin within the first 2% of deformation and continue until fracture, although exceptions were noted. 16 refs., 14 figs., 3 tabs

A Layman's Guide to Geothermal Aquaculture

Energy Technology Data Exchange (ETDEWEB)

Smith, Kenan C

1981-01-01

The following paper is designed as an aid to anyone contemplating a venture into commercially raising giant freshwater prawns, Macrobrachium rosenbergii. Oregon Institute of Technology has been actively involved in a research program to determine the feasibility of such a venture and results to date have been very encouraging. This aquaculture research was initiated in 1975 and was developed as an effort to utilize excess energy from the school’s geothermal heating system. Therefore, most of the information gathered here, will apply to flow-through systems which use geothermal water to maintain a suitable environment for the animals. A study of the market potential for freshwater prawns has been conducted and a favorable response received from wholesale distributors in the Pacific Northwest. Not only is a good market available, but distributors have suggested paying from $4.50 to $5.00 per pound for whole prawns in the size category of 16 to 20 tails to the pound, for a constant fresh supply. By maintaining constant temperatures of 27 degrees Celsius (80 degrees Fahrenheit) ± 1 degree Celsius in our research ponds, we have been able to produce this size prawn in 6 to 8 months.

A Layman's Guide to Geothermal Aquaculture

Energy Technology Data Exchange (ETDEWEB)

Smith, Kenan C.

1981-01-01

The following paper is designed as an aid to anyone contemplating a venture into commercially raising giant freshwater prawns, Macrobrachium rosenbergii. Oregon Institute of Technology has been actively involved in a research program to determine the feasibility of such a venture and results to date have been very encouraging. This aquaculture research was initiated in 1975 and was developed as an effort to utilize excess energy from the school’s geothermal heating system. Therefore, most of the information gathered here, will apply to flow-through systems which use geothermal water to maintain a suitable environment for the animals. A study of the market potential for freshwater prawns has been conducted and a favorable response received from wholesale distributors in the Pacific Northwest. Not only is a good market available, but distributors have suggested paying from $4.50 to $5.00 per pound for whole prawns in the size category of 16 to 20 tails to the pound, for a constant fresh supply. By maintaining constant temperatures of 27 degrees Celsius (80 degrees Fahrenheit) ± 1 degree Celsius in our research ponds, we have been able to produce this size prawn in 6 to 8 months.

Impact of Seasonal Heat Accumulation on Operation of Geothermal Heat Pump System with Vertical Ground Heat Exchanger

Science.gov (United States)

Timofeev, D. V.; Malyavina, E. G.

2017-11-01

The subject of the investigation was to find out the influence of heat pump operation in summer on its function in winter. For this purpose a mathematical model of a ground coupled heat pump system has been developed and programmed. The mathematical model of a system ground heat exchanger uses the finite difference method to describe the heat transfer in soil and the analytical method to specify the heat transfer in the U-tubes heat exchanger. The thermal diffusivity by the heat transfer in the soil changes during gradual freezing of the pore moisture and thus slows soil freezing. The mathematical model of a heat pump includes the description of a scroll compressor and the simplified descriptions of the evaporator and condenser. The analysis showed that heating during the cold season and cooling in the warm season affect the average heat transfer medium temperature in the soil loop in the winter season. It has been also showed that the degree of this effect depends on the clay content in the soil.

Heavy metal: Can molten metal technology turn toxic dross into gold? A study in alchemy, controversy, and green tech

Energy Technology Data Exchange (ETDEWEB)

Lerner, S.

1995-12-31

In a Massachusetts industrial park, inside a renovated helicopter factory, stands a giant, Rube Goldbergesque machine of metal boxes and pipes. Technicians in blue uniforms, hard hats, and safety glasses attend this contraption, watching over the fire at its heart: a cauldron of molten metal, usually iron, heated to some 3,000 degrees Fahrenheit. Hazardous wastes are injected into this molten bath. There, according to its inventor, the metal acts as a catalyst for a chemical reaction that instantly reduces compound molecules to their elemental components. A considerable portion for the wastes thus digested are spit out again in the form of industrial-grade materials, ready for reuse or resale. This article describes both the processing of hazardous wastes by using molten metal to drive reactions that would recover useful materials from hazardous waste and the future possibilities for its use.

Nutritional evaluation of heat treated sunflower meal on the performance of broiler chicks

International Nuclear Information System (INIS)

Ali, S.; Kausar, T.; Shah, W.H.

2004-01-01

Pre-pressed and solvent extracted sunflower meal (SFM) was heated to 90 degree, 100 degree, 110 degree and 120 degree C. Lysine content of SFM decreased from 2.25 to 1.60%. The untreated and heat treated SFM was incorporated in broiler's ration. Maximum weight gain (1525g) and feed efficiency (2.24) were shown by the ration containing SFM heated to 90 degree, which was better than the control ration (weight gain 1454g, feed efficiency 2038). Processing of SFM at higher temperature (100 - 120 degree C) adversely affected weight gain (1388 - 1315g) and feed efficiency (2.46-251). (author)

Evaluation of Criticality of Self-Heating of Polymer Composites by Estimating the Heat Dissipation Rate

Science.gov (United States)

Katunin, A.

2018-03-01

The critical self-heating temperature at which the structural degradation of polymer composites under cyclic loading begins is evaluated by analyzing the heat dissipation rate. The method proposed is an effective tool for evaluating the degradation degree of such structures.

Combination Treatment of Spores of Cl. Botulinum with Heat plus Radiation

Energy Technology Data Exchange (ETDEWEB)

Grecz, N.; Upadhyay, J.; Tang, T. C.; Lin, C. A. [Illinois Institute of Technology, Chicago, IL (United States)

1967-11-15

Radiation resistance of spores of Cl. botulinum is strongly affected by the temperature during irradiation. Very low radiation resistance was consistently observed at 0 Degree-Sign C when samples were in the liquid state. Below 0 Degree-Sign C, the resistance of spores increased because the solidly frozen medium presumably decreased the diffusion of free radicals. As temperature increased above 0 Degree-Sign C processes of radiation protection occurred. When spores were subjected to low levels of radiation (0.6-0.8 Mrad) the heat resistance of the surviving spores was very remarkedly decreased. Experiments were designed to study what kind of radiation damage, i.e. direct hit or indirect action, is responsible for the loss of heat resistance of spores. Indirect effects were reduced by freezing the medium and lowering the temperature during irradiation down to -196 Degree-Sign C. Spores of Cl. botulinum 33A in phosphate buffer were irradiated to 0.6, 0.8 and 1.0 Mrad at irradiation temperatures ranging from +25 to -196 Degree-Sign C and subsequently heated at 99 Degree-Sign C. Survival curves revealed that all spores irradiated at +25 and 0 Degree-Sign C were highly sensitive to heat with D{sub 10} = 5.5 min (after 0.6 Mrad), D{sub 10} = 3.0 min (after 0.8 Mrad) and D{sub 10} = 2.3 min (after 1.0 Mrad). For nonTirradiated controls D10 was 23 min. Pre-irradiation at -25 through -196 Degree-Sign C resulted in a much smaller loss of heat resistance with D{sub 10} clustering around 17.4 min (after 0.6 Mrad), 13. 5 min (after 0.8 Mrad) and 11.5 min (after 1.0 Mrad). Loss of heat resistance after pre-irradiation at +25 and 0 Degree-Sign C was highly influenced by the liquid state of suspending medium whereas at -25 through -196 Degree-Sign C it depended primarily on radiation dose. The mechanism of heat sensitization of spores seems to be related primarily to migrating active free radicals at +25 and 0 Degree-Sign C and to random splitting of molecular bonds at -25 to -196

Subcooled Pool Boiling from Two Tubes of 6 Degree Included Angle in Vertical Alignment

Energy Technology Data Exchange (ETDEWEB)

Kang, Myeong-Gie [Andong National University, Andong (Korea, Republic of)

2015-05-15

One of the major issues in the design of a heat exchanger is the heat transfer in a tube bundle. The passive condensation heat exchanger (PCHX) adopted in APR+ has U-type tube. The PCHX is submerged in the passive condensation cooling tank (PCCT). The heat exchanging tubes are in vertical alignment and inclined at 3 degrees to prevent water hammer as shown in Fig. 1. For the cases, the upper tube is affected by the lower tube. Therefore, the results for a single tube are not applicable to the design of the PCHX. However, the passive heat exchangers are submerged in the subcooled water under atmospheric pressure. The water temperature in the PCCT rises according to the PAFS actuation and reaches the saturation temperature after more than 2.5 hours. Since this period is very important to maintain reactor integrity, the exact evaluation of heat transfer on the tube bundle is indispensable. Although an experimental study on both subcooled and saturated pool boiling of water was performed to obtain local heat transfer coefficients on a 3 degree inclined tube at atmospheric pressure by Kang, no previous results were treating the bundle effect in the subcooled liquid. The heat transfer on the upper tube is enhanced compared with the single tube. The enhancement of the heat transfer on the upper tube is estimated by the bundle effect ( h{sub r} ). It is defined as the ratio of the heat transfer coefficient ( h{sub b} ) for an upper tube in a bundle with lower tubes activated to that for the same tube activated alone in the bundle. The upper tube within a tube bundle can significantly increase nucleated boiling heat transfer compared to the lower tubes at moderate heat fluxes. Summarizing the published results, it is still necessary to identify effects of liquid subcooling on inclined tubes for application to the PCHX design. Therefore, the present study is aimed to study the variations of pool boiling heat transfer on a tube bundle having a 6 degree included angle in

Performances of four magnetic heat-pump cycles

International Nuclear Information System (INIS)

Chen, F.C.; Murphy, R.W.; Mel, V.C.; Chen, G.L.

1990-01-01

Magnetic heat pumps have been successfully used for refrigeration applications at near absolute-zero-degree temperatures. In these applications, a temperature lift of a few degrees in a cryogenic environment is sufficient and can be easily achieved by a simple magnetic heat-pump cycle. To extend magnetic heat pumping to other temperature ranges and other types of applications in which the temperature lift is more than just a few degrees requires more involved cycle processes. This paper investigates the characteristics of a few better-known thermomagnetic heat-pump cycles (Carnot, Ericsson, Stirling, and regenerative) in extended ranges of temperature lift. The regenerative cycle is the most efficient one. For gadolinium operating between 0 and 7 T (Tesla) in a heat pump cycle with a heat-rejection temperature of 320 K, our analysis predicted a 42% loss in coefficient of performance at 260 K cooling temperature, and a 15% loss in capacity at 232 K cooling temperature for the constant-field cycle as compared with the ideal regenerative cycle. Such substantial penalties indicate that the potential irreversibilities from this one source (the additional heat transfer that would be needed for the constant-field vs. the ideal regenerative cycle) may adversely affect the viability of certain proposed MHP concepts if the relevant loss mechanisms are not adequately addressed

Sensitization of rat 9L gliosarcoma cells to low dose rate irradiation by long duration 41 degrees C hyperthermia.

Science.gov (United States)

Armour, E P; Wang, Z H; Corry, P M; Martinez, A

1991-06-15

Modification of survival by long duration, 41 degrees C hyperthermia in combination with low dose rate radiation (0.5 Gy/h) was determined in rat 9L gliosarcoma cells. Cells were exposed to radiation in a manner that simulated continuous irradiation at a dose rate relevant to clinical brachytherapy. High dose rate X-irradiation was fractionated in 1.0-Gy fractions at 2-h intervals (FLDRI). Previous studies had demonstrated that 9L cells exposed to FLDRI with these parameters have survival characteristics that are equivalent to continuous low dose rate irradiation. Cells exposed to 41 degrees C throughout FLDRI were sensitized significantly (thermal enhancement ratio of 2.07) compared with cells irradiated at 37 degrees C. Incubation for 24 h at 41 degrees C before and/or after FLDRI at either 37 degrees C or 41 degrees C did not increase the slope of the radiation survival curves but did reduce the shoulder. Similarly, heating at 43 degrees C for 30 or 60 min before and/or after irradiation at 0.5 Gy/h also did not enhance cell sensitivity. Survival of cells after irradiation at high dose rate (60 Gy/h) was independent of the temperature during irradiation. Preheat at 41 degrees C for 24 h did not sensitize cells to high dose rate irradiation by increasing the slope of the survival curve, although a loss of shoulder was observed. Sensitization of cells heated at 43 degrees C for 30 or 60 min before high dose rate irradiation was expressed as classical slope modification. Our results demonstrate that 41 degrees C heating during FLDRI greatly sensitizes cells to radiation-induced killing for exposure durations up to 36 h. Heating 9L cells at 41 degrees C or 43 degrees C adjacent to FLDRI at 0.5 Gy/h resulted in no additional enhancement of terminal sensitivity, although shoulder modification was observed. The sensitization by simultaneous heating described above occurred even though thermotolerance developed during extended incubation at 41 degrees C. These in vitro

Induction Heating on Dynamic Tensile Tests in CEA Saclay

International Nuclear Information System (INIS)

Averty, X.; Yvon, P.; Duguay, C.; Pizzanelli, J. P.; Basini, V.

2001-01-01

The LCMI (Laboratory for characterization of irradiated materials), located in CEA from Saclay, is in charge of the mechanical tests on irradiated materials. The dynamic tensile testing machine, in a hot cell equipped with two remote handling, has been first improved in 1995, to fulfill the French safety programs on Reactivity Initiated Accident (RIA). One objective of this machine is to obtain mechanical property data on current Zircaloy cladding types needed to quality the cladding's response under RIA or LOCA transient loading and thermal conditions. For the RIA, this means testing at strain rates up to 5 s' and heating rates up to 200 degree centigree-s''-1, while for Loss of Coolant Accidents (LOCA) testing at strain rates of 10''-3 s''-1 and heating rates of 20 degree centigree s''-1 would be appropriate. The tensile samples are machined with a spark erosion machine, directly from pieces of cladding previously de fueled. Two kinds of samples can be machined in the cladding. Axial samples in order to test axial mechanical characteristics Ring samples in order to test transverse mechanical characteristics, more representative of RIA conditions. On one hand, the axial tensile tests were performed using the Joule effect, and heating rates up to about 500 degree centigree .s''-1 were obtained. This enabled us to perform the axial tests in a satisfactory manner. On the other hand, the tensile ring were first performed in a vertical furnace with a heating rate about 0.2 degree centigree.s''-1 and a thermal stability about 1 degree centigree. For temperatures above 480 degree centigree, the mechanical characteristics showed a sharp drop which could be attributed to irradiation defect annealing. Therefore we have recently developed an induction heating system to reach heating rates high enough (200 degree centigree.s''-1) to prevent any significant annealing before performing the ring tensile tests. To apply a uniaxial tangential tension, two matching half

Research and development of utilization technology of solar thermal system for industrial and other use. Development of system of advanced heat process type (chemical refrigeration and cold storage system using solar heat); Sangyoyo nado solar system jitsuyoka gijutsu kaihatsu. Advanced heat process gata system no kaihatsu (taiyonetsu reito reizo no kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

Takita, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

1994-12-01

Described herein are the results of the FY1994 research program for chemical refrigeration and cold storage system using solar heat. The study on refrigeration materials are aimed at development of new hydrogen-occluding alloys which show good hydrogenation equilibrium characteristics and reactivity at temperature required for stand-alone refrigeration systems aided by solar heat, and still new hydrogen-occluding alloys operable at refrigeration temperature for lower-temperature systems. For the refrigeration materials capable of producing low-temperature heat of -10{degree}C at a regeneration temperature of 140{degree}C produced by solar heat, a La-Ni-Mn-Al alloy is selected for high-temperature use and a La-Y-Ni-Mn alloy for low-temperature use. The study on technology for refrigeration modules develops high-efficiency heat exchangers for refrigeration and regeneration, compatible with the hydrogen-occluding alloys. It also develops air-and water-cooling techniques for hydrogen-occluding alloys, where air is used as the heat source. The test apparatus is designed, installed and operated, to attain a low temperature of -10{degree}C or lower with a heat source of 140{degree}C and air heat source of 28{degree}C. 7 figs.

Investigation af a solar heating system for space heating and domestic hot water supply with a high degree of coverage

DEFF Research Database (Denmark)

Vejen, Niels Kristian

1999-01-01

A solar storage tank for space heating and domestic hot water supply was designed and testet in af laboratory test facility.......A solar storage tank for space heating and domestic hot water supply was designed and testet in af laboratory test facility....

77 FR 751 - Federal Motor Vehicle Safety Standards; Matters Incorporated by Reference

Science.gov (United States)

2012-01-06

... Recommended Practice J1133, ``School Bus Stop Arm,'' revised April 1984, into Sec. 571.131. (45) SAE Standard... constriction requirement of S5.3.1 after having been subjected to a temperature of 248 degrees Fahrenheit (120... mandatory requirements. * * * * * S6.4.5 School bus signal lamp aiming. Each school bus signal lamp must be...

Evaluation of Sampling and Sample Preparation Modifications for Soil Containing Metallic Residues

Science.gov (United States)

2012-01-01

cubic meters (m3) cubic inches (in3) 1.6387064×10−5 cubic meters (m3) degrees Fahrenheit (°F) − 32 1/1.8 degrees Celsius (°C) feet (ft) 0.3048...249 399 B49-23 11 Puck 120 6205 30.0 0.55 7.83 231 404 B49-24 12 Puck 120 6295 28.6 0.58 7.79 227 451 B49-25 13 Puck 120 6755 28.5

Mississippi Coastal Improvements Program; Evaluation of Barrier Island Restoration Efforts

Science.gov (United States)

2013-09-01

451   ERDC TR-13-12 xx Figure G-14. Alternative #1 Restored conditions for Storm #2; Template C; Without borrow pits. ......... 451   Figure G-15...0.02831685 cubic meters cubic yards 0.7645549 cubic meters degrees Fahrenheit (F-32)/1.8 degrees Celsius feet 0.3048 meters inches 0.0254 meters...conditions for Storm #2; Template A; Without borrow pits. ERDC TR-13-12 451 Figure G-13. Alternative #1 Restored conditions for Storm #2; Template B

Energy, Carbon-emission and Financial Savings from Thermostat Control

Energy Technology Data Exchange (ETDEWEB)

Blasing, T J [ORNL; Schroeder, Dana [University of Georgia, Athens, GA

2013-08-01

Among the easiest approaches to energy, and cost, savings for most people is the adjustment of thermostats to save energy. Here we estimate savings of energy, carbon, and money in the United States of America (USA) that would result from adjusting thermostats in residential and commercial buildings by about half a degree Celsius downward during the heating season and upward during the cooling season. To obtain as small a unit as possible, and therefore the least likely to be noticeable by most people, we selected an adjustment of one degree Fahrenheit (0.56 degree Celsius) which is the gradation used almost exclusively on thermostats in the USA and is the smallest unit of temperature that has been used historically. Heating and/or cooling of interior building space for personal comfort is sometimes referred to as space conditioning, a term we will use for convenience throughout this work without consideration of humidity. Thermostat adjustment, as we use the term here, applies to thermostats that control the indoor temperature, and not to other thermostats such as those on water heaters. We track emissions of carbon only, rather than of carbon dioxide, because carbon atoms change atomic partners as they move through the carbon cycle, from atmosphere to biosphere or ocean and, on longer time scales, through the rock cycle. To convert a mass of carbon to an equivalent mass of carbon dioxide (thereby including the mass of the 2 oxygen atoms in each molecule) simply multiply by 3.67.

Decontamination of drinking water by direct heating in solar panels.

Science.gov (United States)

Fjendbo Jørgensen, A J; Nøhr, K; Sørensen, H; Boisen, F

1998-09-01

A device was developed for direct heating of water by solar radiation in a flow-through system of copper pipes. An adjustable thermostat valve prevents water below the chosen temperature from being withdrawn. The results show that it is possible to eliminate coliform and thermotolerant coliform bacteria from naturally contaminated river water by heating to temperatures of 65 degrees C or above. Artificial additions of Salmonella typhimurium, Streptococcus faecalis and Escherichia coli to contaminated river water were also inactivated after heating to 65 degrees C and above. The total viable count could be reduced by a factor of 1000. The heat-resistant bacteria isolated from the Mlalakuva River (Tanzania) were spore-forming bacteria which exhibited greater heat resistance than commonly used test bacteria originating from countries with colder climates. To provide a good safety margin it is recommended that an outlet water temperature of 75 degrees C be used. At that temperature the daily production was about 501 of decontaminated water per m2 of solar panel, an amount that could be doubled by using a heat exchanger to recycle the heat.

Heat transfer enhancement in heat exchangers by longitudinal vortex generators

International Nuclear Information System (INIS)

Guntermann, T.; Fiebig, M.; Mitra, N.K.

1990-01-01

In this paper heat transfer enhancement and flow losses are computed for the interaction of a laminar channel flow with a pair of counterrotating longitudinal vortices generated by a pair of delta-winglets punched out of the channel wall. The geometry simulates an element of a fin-plate or fin-tube heat exchanger. The structure of the vortex flow and temperature distribution, the local heat transfer coefficients and the local flow losses are discussed for a sample case. For a Reynolds number of Re d = 1000 and a vortex generator angle of attack of β = 25 degrees heat transfer is enhanced locally by more than 300% and in the mean by 50%. These values increase further with Re and β

Local heat transfer around a wall-mounted cube. Case of the attack angle of 45 deg.; Rippotai tokki mawari no kyokusho netsu dentatsu. Katamukikaku 45 degrees no baai

Energy Technology Data Exchange (ETDEWEB)

Nakamura, H.; Igarashi, T.; Tsutsui, T. [National Defense Academy, Kanagawa (Japan)

1999-11-25

An experimental study was performed to investigate the local heat transfer around a cube mounted on the wall. The cube lied in the turbulent boundary layer. The flow angle of attack to the cube was 15 degree. The Reynolds number ranged from 4.2 x 10{sup 3} to 3.3 x 10{sup 4}. The surface temperature distributions around time cube were measured with thermocouples tinder the condition of a constant heat flux. The local h eat transfer is very high near the front corner on the top face of the cube. This high heat transfer region extends from the front corner to downstream along both edges. This is caused by the formation of lamb horn vortex. The local heat transfer is also high in time region of horseshoe vortex formed a round the cube. On the wall behind the cube, there is a pair of minimum heat transfer region. The average Nusselt number on each face of the cube is given as a function of Reynolds number. The overall Nusselt number of time cube is expressed by Nu{sub m}=0.43Re{sup 0.58}. (author)

Optimization of triangular microchannel heat sinks using constructible theory

International Nuclear Information System (INIS)

Mardani, Moloud; Salimpour, Mohammad Reza

2016-01-01

The present paper examines the optimization of triangular microchannel heat sinks. The impact of volume fraction of solid material and pressure drop on the maximum temperature of the microchannel heat sinks are investigated and their optimum operating conditions are compared. From the results, it is seen that increasing the side angle of the triangular microchannel, improves its performance. Furthermore, there is an appropriate agreement between the analytical and numerical results. Finally, the effect of degrees of freedom on the performance of microchannels is investigated. To accomplish this end, the triangular microchannels with the side angle of 60 degree have been chosen as it has the best performance compared to other microchannels. It is observed that the minimized maximum temperatures of optimized microchannel heat sinks with three degrees of freedom are 10% lower than the ones with two degrees of freedom

Acquired Thermotolerance and Heat Shock Proteins in Thermophiles from the Three Phylogenetic Domains

DEFF Research Database (Denmark)

Trent, Jonathan D.; Gabrielsen, Mette; Jensen, Bo

1994-01-01

Thermophilic organisms from each of the three phylogenetic domains (Bacteria, Archaea, and Eucarya) acquired thermotolerance after heat shock. Bacillus caldolyticus grown at 60 degrees C and heat shocked at 69 degrees C for 10 min showed thermotolerance at 74 degrees C, Sulfolobus shibatae grown...

Modulation of oral heat and cold pain by irritant chemicals.

Science.gov (United States)

Albin, Kelly C; Carstens, Mirela Iodi; Carstens, E

2008-01-01

Common food irritants elicit oral heat or cool sensations via actions at thermosensitive transient receptor potential (TRP) channels. We used a half-tongue, 2-alternative forced-choice procedure coupled with bilateral pain intensity ratings to investigate irritant effects on heat and cold pain. The method was validated in a bilateral thermal difference detection task. Capsaicin, mustard oil, and cinnamaldehyde enhanced lingual heat pain elicited by a 49 degrees C stimulus. Mustard oil and cinnamaldehyde weakly enhanced lingual cold pain (9.5 degrees C), whereas capsaicin had no effect. Menthol significantly enhanced cold pain and weakly reduced heat pain. To address if capsaicin's effect was due to summation of perceptually similar thermal and chemical sensations, one-half of the tongue was desensitized by application of capsaicin. Upon reapplication, capsaicin elicited little or no irritant sensation yet still significantly enhanced heat pain on the capsaicin-treated side, ruling out summation. In a third experiment, capsaicin significantly enhanced pain ratings to graded heat stimuli (47 degrees C to 50 degrees C) resulting in an upward shift of the stimulus-response function. Menthol may induce cold hyperalgesia via enhanced thermal gating of TRPM8 in peripheral fibers. Capsaicin, mustard oil, and cinnamaldehyde may induce heat hyperalgesia via enhanced thermal gating of TRPV1 that is coexpressed with TRPA1 in peripheral nociceptors.

Comparison of NEXRAD multisensor precipitation estimates to rain gage observations in and near DuPage County, Illinois, 2002–12

Science.gov (United States)

Spies, Ryan R.; Over, Thomas M.; Ortel, Terry W.

2018-05-21

provides an analysis of spatially combined NEXRAD–MPE precipitation data as a function of temperature at an hourly time scale and indicates, among other results, that most precipitation in the study area occurs at moderate temperatures of 30 to 74 degrees Fahrenheit. However, when precipitation does occur, its intensity increases with temperature to about 86 degrees Fahrenheit.

District heating with SLOWPOKE energy systems

International Nuclear Information System (INIS)

Lynch, G.F.

1988-03-01

The SLOWPOKE Energy System, a benign nuclear heat source designed to supply 10 thermal megawatts in the form of hot water for local heating systems in buildings and institutions, is at the forefront of these developments. A demonstration unit has been constructed in Canada and is currently undergoing an extensive test program. Because the nuclear heat source is small, operates at atmospheric pressure, and produces hot water below 100 degrees Celcius, intrinsic safety features will permit minimum operator attention and allow the heat source to be located close to the load and hence to people. In this way, a SLOWPOKE Energy System can be considered much like the oil- or coal-fired furnace it is designed to replace. The low capital investment requirements, coupled with a high degree of localization, even for the first unit, are seen as attractive features for the implementation of SLOWPOKE Energy Systems in many countries

Studies on heat storage, 9

International Nuclear Information System (INIS)

Taoda, Hiroshi; Hayakawa, Kiyoshi; Kawase, Kaoru; Kosaka, Mineo

1985-01-01

To estimate the extent of thermal oxidative aging of the crosslinked and surface coated polyethylene pellets used as a latent heat thermal storage material, their deterioration was investigated by applying the heating-cooling cycle which simulated the daily insolation over 6 months (8-hour holding at 150 deg C as the highest temperature in a day followed by 5-hour holding at 30 deg C as the lowest one). The degradation, e.g., the lowering of heat of crystallization and in crystallization temperature, is thought to be caused by both the decrease in molecular weight of polyethylene due to thermal oxidative decomposition and the crosslinking between produced radicals. With the increase in the degree of crosslinking and branching in a molecular chain which has low bond dissociation energy, thermal deterioration of polyethylene proceeds more rapidly. Polyethylene pellets can endure long periods of practical heat cycling as a thermal storage material when they are treated with radical scavengers under proper control of their crosslinking degrees. The repeating heat storage experiments by using the developed polyethylene thermal storage material were performed and very promising results were obtained. (author)

Fracture toughness testing of V-4Cr-4Ti at 25{degrees}C and -196{degrees}C

Energy Technology Data Exchange (ETDEWEB)

Li, H.X.; Kurtz, R.J. [Pacific Northwest National Lab., Richland, WA (United States)

1996-10-01

Measurements of the fracture toughness of the production-scale heat (832665) of V-4Cr-4Ti have been performed at 25{degrees}C and {minus}196{degrees}C using compact tension (CT) specimens. Test specimens were vacuum annealed at either 1000{degrees}C for 1 hour (HT1) or 1050{degrees}C for two hours (HT2). Specimens given the HT1 treatment were annealed after final machining, whereas the HT2 specimens received the 1050{degrees}C anneal at Teledyne Wah Chang prior to final machining. Following machining HT2 specimens were then vacuum annealed at 180{degrees}C for two hours to remove hydrogen. Specimens treated using HT1 had a partially recrystallized microstructure and those treated using HT2 had a fully recrystallized microstructure. The fracture toughness at 25{degrees}C was determined by J-integral tests and at {minus}196{degrees}C by ASTM E 399 type tests. Toughness values obtained at {minus}196{degrees}C were converted to J-integral values for comparison to the 25{degrees}C data. The 25{degrees}C fracture toughness was very high with none of the specimens giving valid results per ASTM criteria. Specimens fractured by microvoid coalescence. The fracture toughness at {minus}196{degrees}C was much lower than that at 25{degrees}C and the fracture surface showed predominantly cleavage features. The present results show a transition from ductile to brittle behavior with decreasing test temperature which is not observed from one-third scale Charpy impact tests. The fracture toughness at {minus}196{degrees}C was still quite high, however, at about 75 kJ/m{sup 2}. Delaminations in planes normal to the thickness direction were seen at both test temperatures. Fracture surfaces inside the delaminations exhibited nearly 100% cleavage facets. The cause of the brittle delaminations was not determined, but will be a subject for further investigation.

Heat-Related Illnesses

Medline Plus

Full Text Available ... weak pulse; rapid, shallow breathing; vomiting; and increased body temperature of more than 104 degrees. People with ... nausea, loss of consciousness, vomiting or a high body temperature. For late stage heat stroke symptoms, cool ...

Reclamation challenges at Usibelli Coal Mine in Healy, Alaska

International Nuclear Information System (INIS)

Jackson, L.P.

1998-01-01

Successful reclamation in the Interior of Alaska requires planning in order to avoid major setbacks. Usibelli Coal Mine is located at a North Latitude of approximately 64 degrees. Temperature extremes in the Interior of Alaska range from a high of 90 degrees Fahrenheit to a low of minus 60 degrees Fahrenheit. The challenges in this sub-arctic climate are many. Several unique reclamation challenges are present due to the cold climate. Discontinuous permafrost is prevalent on north facing slopes. This presents stability problems if placed in inappropriate locations. Very detailed planning is required to assure that no stability problems occur. The construction of drainage channels in ice-rich permafrost areas also requires extra care to assure that water flows along the surface rather than down into the spoil. Mineral topsoil is often not present on the areas to be mined. Often non-salvageable organic permafrost soils are present. These require special handling and must be isolated to avoid stability problems. Since the ground is frozen for 7--8 months a year the reestablishment of vegetation requires a very aggressive planting schedule. Grass seed is applied by fixed wing aircraft and shrubs are planted from locally collected seed. By planning properly prior to mining successful reclamation can take place in the Interior of Alaska

Evaluation of heat treatment schedules for emerald ash borer (Coleoptera: Buprestidae).

Science.gov (United States)

Myers, Scott W; Fraser, Ivich; Mastro, Victor C

2009-12-01

The thermotolerance of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), was evaluated by subjecting larvae and prepupae to a number of time-temperature regimes. Three independent experiments were conducted during 2006 and 2007 by heating emerald ash borer infested firewood in laboratory ovens. Heat treatments were established based on the internal wood temperature. Treatments ranged from 45 to 65 degrees C for 30 and 60 min, and the ability of larvae to pupate and emerge as adults was used to evaluate the success of each treatment. A fourth experiment was conducted to examine heat treatments on exposed prepupae removed from logs and subjected to ambient temperatures of 50, 55, and 60 degrees C for 15, 30, 45, and 60 min. Results from the firewood experiments were consistent in the first experiment. Emergence data showed emerald ash borer larvae were capable of surviving a temperatures-time combination up to 60 degrees C for 30 min in wood. The 65 degrees C for 30 min treatment was, however, effective in preventing emerald ash borer emergence on both dates. Conversely, in the second experiment using saturated steam heat, complete mortality was achieved at 50 and 55 degrees C for both 30 and 60 min. Results from the prepupae experiment showed emerald ash borer survivorship in temperature-time combinations up to 55 degrees C for 30 min, and at 50 degrees C for 60 min; 60 degrees C for 15 min and longer was effective in preventing pupation in exposed prepupae. Overall results suggest that emerald ash borer survival is variable depending on heating conditions, and an internal wood temperature of 60 degrees C for 60 min should be considered the minimum for safe treatment for firewood.

The Swiss heating reactor (SHR) for district heating of small communities

International Nuclear Information System (INIS)

Burgsmueller, P.; Jacobi, A.Jr.; Jaeger, J.F.; Klaentschi, M.J.; Seifritz, W.; Vuillemier, F.; Wegmann, F.

1987-01-01

With fossil fuel running out in a foreseeable future, it is essential to develop substitution strategies. Some 40-50 % of the heat demand in industrial countries is below 120 degrees C, for space heating and warm water production, causing a corresponding fraction of air pollution by SO 2 and to a lesser extent NO x if fossil fuels are used. Yet, contemporary LWR technology makes it feasible to supply a district heating network without basically new reactor development. Units in the power range 10-50 MW are most suitable for Switzerland, both in respect of network size and of the democratic decision making structure. A small BWR for heating purpose is being developed by parts of the Swiss Industry and the Swiss Federal Institute for Reactor Research (EIR). The economic target of 100-120 SFr/MWh heat at the consumer's seems achievable. (author)

Heat exchanger tube inspection using ultrasonic arrays

International Nuclear Information System (INIS)

Meyer, P.A.; Carodiskey, T.J.

1986-01-01

Tubing used in industrial heat exchangers is often subject to failure caused by corrosion and cracking. Technical conferences are used as a forum in the steam generator industry to ensure that the failure mechanisms are well understood and that the quality of the heat exchanger is maintained. The quality of a heat exchanger can be thought of as its ability to operate to design specifications over its intended life. This is the motivation to inspect and evaluate these devices periodically. Inspection, however, normally requires shutdown of the heat exchanger which is costly but is much more acceptable than an unscheduled shutdown due to failure of a tube. Therefore, the degree of inspection is established by balancing the cost of inspection with the risk of a tube failure. Any method of reducing the cost of inspection will permit a higher degree of inspection and, therefore, improve heat exchanger quality. This paper reviews the design and performance of an improved method of ultrasonic inspection of heat exchanger tubing with emphasis on applications in the nuclear industry

Heat-Related Illnesses

Medline Plus

Full Text Available ... weak pulse; rapid, shallow breathing; vomiting; and increased body temperature of more than 104 degrees. People with these ... nausea, loss of consciousness, vomiting or a high body temperature. For late stage heat stroke symptoms, cool the ...

Thermoreceptive innervation of human glabrous and hairy skin: a contact heat evoked potential analysis.

Science.gov (United States)

Granovsky, Yelena; Matre, Dagfinn; Sokolik, Alexander; Lorenz, Jürgen; Casey, Kenneth L

2005-06-01

The human palm has a lower heat detection threshold and a higher heat pain threshold than hairy skin. Neurophysiological studies of monkeys suggest that glabrous skin has fewer low threshold heat nociceptors (AMH type 2) than hairy skin. Accordingly, we used a temperature-controlled contact heat evoked potential (CHEP) stimulator to excite selectively heat receptors with C fibers or Adelta-innervated AMH type 2 receptors in humans. On the dorsal hand, 51 degrees C stimulation produced painful pinprick sensations and 41 degrees C stimuli evoked warmth. On the glabrous thenar, 41 degrees C stimulation produced mild warmth and 51 degrees C evoked strong but painless heat sensations. We used CHEP responses to estimate the conduction velocities (CV) of peripheral fibers mediating these sensations. On hairy skin, 41 degrees C stimuli evoked an ultra-late potential (mean, SD; N wave latency: 455 (118) ms) mediated by C fibers (CV by regression analysis: 1.28 m/s, N=15) whereas 51 degrees C stimuli evoked a late potential (N latency: 267 (33) ms) mediated by Adelta afferents (CV by within-subject analysis: 12.9 m/s, N=6). In contrast, thenar responses to 41 and 51 degrees C were mediated by C fibers (average N wave latencies 485 (100) and 433 (73) ms, respectively; CVs 0.95-1.35 m/s by regression analysis, N=15; average CV=1.7 (0.41) m/s calculated from distal glabrous and proximal hairy skin stimulation, N=6). The exploratory range of the human and monkey palm is enhanced by the abundance of low threshold, C-innervated heat receptors and the paucity of low threshold AMH type 2 heat nociceptors.

Heating tar sands formations to visbreaking temperatures

Science.gov (United States)

Karanikas, John Michael [Houston, TX; Colmenares, Tulio Rafael [Houston, TX; Zhang, Etuan [Houston, TX; Marino, Marian [Houston, TX; Roes, Augustinus Wilhelmus Maria [Houston, TX; Ryan, Robert Charles [Houston, TX; Beer, Gary Lee [Houston, TX; Dombrowski, Robert James [Houston, TX; Jaiswal, Namit [Houston, TX

2009-12-22

Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat may be controlled so that at least a majority of the section reaches an average temperature of between 200.degree. C. and 240.degree. C., which results in visbreaking of at least some hydrocarbons in the section. At least some visbroken hydrocarbon fluids may be produced from the formation.

Study of Army Design Hover Criteria

Science.gov (United States)

2017-09-01

INFORMATION SECURITY PROGRAM REGULATION, CHAPTER IX. FOR UNCLASSIFIED, LIMITED DOCUMENTS, DESTROY BY ANY METHOD THAT WILL PREVENT DISCLOSURE OF...margin at 4,000 feet pressure altitude and 95 degree Fahrenheit ambient temperature design point. This recommendation did not account for diurnal...margin capability to account for realistic helicopter operating conditions. However, the design point remained at 4K/95 for development and

Mine Safety Detection System (MSDS)

Science.gov (United States)

2012-09-01

as the sub-freezing arctic to equatorial values as high as 122 degrees Fahrenheit ( approximately 50°C).  water salinity ranging from fresh to...16 408 0.24 17 421 0.20 18 431 0.15 19 451 0.10 20 509 0.05 Table 13. SOH Search Time Summary 61 Since most mine to sensor ranges do not

Incorporation of radiolabeled whey proteins into casein micelles by heat processing

International Nuclear Information System (INIS)

Noh, B.; Richardson, T.

1989-01-01

Skim milk was heated at .70, 95, and 140 degree C to simulate the processes of pasteurization, forewarming, and UHT sterilization, and the specific interactions between α-lactalbumin or β-lactoglobulin and the caseins studied using tracer amounts of added 14 C-labeled whey protein. Radioactivities of the whey and of the washed casein pellets from renneted skim milk were measured and the extent of the interaction estimated. Upon heating skim milk at 70 degree C for 45 s, less than 2% β-lactoglobulin and less than .3% α-lactalbumin were incorporated into the curd. Heating at 95 degree C for .5 to 20 min resulted in 58 to 85% of the β-lactoglobulin and 8 to 55% of the α-lactalbumin becoming associated with the curd. Heating at 140 degree C for 2 and 4 s caused 43 and 54% of the β-lactoglobulin and 9 and 12% of the α-lactalbumin, respectively, to be bound to the curd fraction. The radiolabeling technique is very sensitive and useful for tracing low levels of interaction between whey proteins and casein in heated milk systems

Heat treatment of the common furniture beetle Anobium punctatum (Coleoptera: Anobiidae), at temperature between 45 degrees and 54 degrees C. under dry and humid conditions

DEFF Research Database (Denmark)

Hansen, Lise Stengaard; Jensen, Karl-Martin Vagn

1998-01-01

The combinations of exposure times and temperatures (45 degrees to 54 degrees C.) without addition of moisture necessary to obtain 100 per cent mortality were determined on all stages of commn furniture beetle, Anobium punctatum. Lethal combinations vary from minutes at 46 degrees to 5 minutes...

Six-phase soil heating accelerates VOC extraction from clay soil

International Nuclear Information System (INIS)

Gauglitz, P.A.; Roberts, J.S.; Bergsman, T.M.; Caley, S.M.; Heath, W.O.; Miller, M.C.; Moss, R.W.; Schalla, R.; Jarosch, T.R.; Eddy-Dilek, C.A.

1994-08-01

Six-Phase Soil Heating (SPSH) was demonstrated as a viable technology for heating low permeability soils containing volatile organic contaminants. Testing was performed as part of the Volatile Organic Compounds in Non-Arid Soils Integrated Demonstration (VOC Non-Arid ID) at the Savannah River Site. The soil at the integrated demonstration site is contaminated with perchloroethylene (PCE) and trichloroethylene (TCE); the highest soil contamination occurs in clay-rich zones that are ineffectively treated by conventional soil vapor extraction due to the very low permeability of the clay. The SPSH demonstration sought to heat the clay zone and enhance the performance of conventional soil vapor extraction. Thermocouples at thirty locations quantified the areal and vertical heating within the treated zone. Soil samples were collected before and after heating to quantify the efficacy of heat-enhanced vapor extraction of PCE and TCE from the clay soil. Samples were taken (essentially every foot) from six wells prior to heating and adjacent to these wells after heating. Results show that contaminant removal from the clay zone was 99.7% (median) within the electrode array. Outside the array where the soil was heated, but to only 50 degrees C, the removal efficiency was 93%, showing that heating accelerated the removal of VOCs from the clay soil. The accelerated remediation resulted from effective heating of the contaminated clay zone by SPSH. The temperature of the clay zone increased to 100 degrees C after 8 days of heating and was maintained near 100 degrees C for 17 days. Electrical heating removed 19,000 gal of water from the soil as steam, with peak removal rate of 1,500 gpd of condensed steam

Degree-degree correlations in random graphs with heavy-tailed degrees

NARCIS (Netherlands)

Hofstad, van der R.W.; Litvak, N.

2014-01-01

Mixing patterns in large self-organizing networks, such as the Internet, the World Wide Web, social, and biological networks are often characterized by degree-degree dependencies between neighboring nodes. In assortative networks, the degree-degree dependencies are positive (nodes with similar

Degree-Degree Dependencies in Random Graphs with Heavy-Tailed Degrees

NARCIS (Netherlands)

van der Hofstad, Remco; Litvak, Nelly

2014-01-01

Mixing patterns in large self-organizing networks, such as the Internet, the World Wide Web, social, and biological networks are often characterized by degree-degree dependencies between neighboring nodes. In assortative networks, the degree-degree dependencies are positive (nodes with similar

Streamlined energy-savings calculations for heat-island reduction strategies

Energy Technology Data Exchange (ETDEWEB)

Akbari, Hashem; Konopacki, Steven J.

2003-03-15

We have developed summary tables (sorted by heating- and cooling-degree-days) to estimate the potential of Heat-Island Reduction (HIR) strategies (i.e., solar-reflective roofs, shade trees, reflective pavements, and urban vegetation) to reduce cooling-energy use in buildings. The tables provide estimates of savings for both direct effect (reducing heat gain through the building shell) and indirect effect (reducing the ambient air temperature). In this analysis, we considered three building types that offer the most savings potential : residences, offices, and retail stores. Each building type was characterized in detail by Pre-1980 (old) or 1980+ (new) construction vintage and with natural gas or electricity as heating fuel. We defined prototypical-building characteristics for each building type and simulated the effects of HIR strategies on building cooling and heating energy use and peak power demand using the DOE-2.1E model and weather data for about 240 locations in the U.S. A statistical analysis of previously completed simulations for five cities was used to estimate the indirect savings. Our simulations included the effect of (1) solar-reflective roofing material on building [direct effect], (2) placement of deciduous shade trees near south and west walls of building [direct effect], and (3) ambient cooling achieved by urban reforestation and reflective building surfaces and pavements [indirect effect]. Upon completion of estimating the direct and indirect energy savings for all the selected locations, we integrated the results in tables arranged by heating- and cooling-degree-days. We considered 15 bins for heating-degree-days, and 11 bins for cooling-degree-days. Energy use and savings are presented per 1000 ft2 of roof area. In residences heated with gas and in climates with greater than 1000 cooling-degree-days, the annual electricity savings in Pre-1980 stock ranged from 650 to 1300 kWh/1000ft2; for 1980+ stock savings ranged 300 to 600 kWh/1000 ft2

Decreased survival of prostate cancer cells in vitro by combined treatment of heat and an antioxidant inhibitor diethyldithiocarbamate (DDC).

Science.gov (United States)

Moriyama-Gonda, Nobuko; Igawa, Mikio; Shiina, Hiroaki; Urakami, Shinji; Terashima, Masaharu

2003-11-01

The aim of this study was to examine a modulation of thermotolerance by treatment with combination of heat and the antioxidant inhibitor diethyldithiocarbamate (DDC) of the PC-3 prostate cancer cells. To determine thermotolerance, cells were heated once or twice. Two 1 h exposures at 43 degrees C, with a recovery period in between, revealed better survival/recovery of cells after the second exposure than after the first (fig. 1A + 1B). Additional experiments were performed, heating cells twice (fig. 1B + 1C). First, cells were heated at 43 degrees C for 1 h and, after various recovery times (intervals) at 37 degree C, subsequently reheated at 44 degrees C for 1 h. To ensure effective cell killing, efficiency of the combined treatments of 1 mM DDC and heating at 43 or 44 degrees C for 1 h was estimated by measuring cell survival, reactive oxygen species (ROS) generation, superoxide dismutase (SOD) activity and heat shock protein 70 (hsp 70) expression. To obtain a more effective method for subsequent heat exposure, cells were heated twice after a 24 h interval in the presence or absence of 1 mM DDC. ROS generation and SOD activity immediately increased correlating with duration of heating, but their levels gently decreased with time after discontinuation of heating. On the other hand, hsp 70 levels slowly increased, also correlating with duration of heating but continued to increase with time after discontinuation of heating for a certain period. DDC administration coupled with heating at 43 or 44 degrees C significantly decreased cell survival compared to heating alone (p DDC as compared to heat alone at 43 and 44 degrees C (p DDC could have potential benefits in the treatment of prostate cancer.

Environmental Setting of the Lower Merced River Basin, California

Science.gov (United States)

Gronberg, Jo Ann M.; Kratzer, Charles R.

2006-01-01

In 1991, the U.S. Geological Survey began to study the effects of natural and anthropogenic influences on the quality of ground water, surface water, biology, and ecology as part of the National Water-Quality Assessment (NAWQA) Program. As part of this program, the San Joaquin-Tulare Basins study unit is assessing parts of the lower Merced River Basin, California. This report provides descriptions of natural and anthropogenic features of this basin as background information to assess the influence of these and other factors on water quality. The lower Merced River Basin, which encompasses the Mustang Creek Subbasin, gently slopes from the northeast to the southwest toward the San Joaquin River. The arid to semiarid climate is characterized by hot summers (highs of mid 90 degrees Fahrenheit) and mild winters (lows of mid 30 degrees Fahrenheit). Annual precipitation is highly variable, with long periods of drought and above normal precipitation. Population is estimated at about 39,230 for 2000. The watershed is predominately agricultural on the valley floor. Approximately 2.2 million pounds active ingredient of pesticides and an estimated 17.6 million pounds active ingredient of nitrogen and phosphorus fertilizer is applied annually to the agricultural land.

Experimental study of heat transfer in a heat exchanger with rectangular channels

International Nuclear Information System (INIS)

Hammami, Mahmoud; Ben Said, Akrem; Ben Maad, Rejeb; Rebay, Mourad

2009-01-01

This paper presents the results of an experimental study related to characterisation of a mini channel heat exchanger. Such heat exchanger may be used in water cooling of electronic components. The results obtained show the efficiency of this exchanger even with very low water flow rates. Indeed, in spite of the importance of the extracted heat fluxes which can reach about 50Kw/m 2 , the temperature of the cooled Aluminium bloc remained always lower than the tolerated threshold of 80 degree in electronic cooling. Moreover, several thermal characteristics such as equivalent thermal resistance of the exchanger, the average internal convective heat transfer coefficient and the increase in the temperature of the cooling water have been measured. The results presented have been obtained with in q uinconce r ectangular mini-channel heat exchanger, with a hydraulic diameter D h = 2mm. NOMENCLATURE h D Hydraulic diameter (mm). int

Lithium-ion battery structure that self-heats at low temperatures

Science.gov (United States)

Wang, Chao-Yang; Zhang, Guangsheng; Ge, Shanhai; Xu, Terrence; Ji, Yan; Yang, Xiao-Guang; Leng, Yongjun

2016-01-01

Lithium-ion batteries suffer severe power loss at temperatures below zero degrees Celsius, limiting their use in applications such as electric cars in cold climates and high-altitude drones. The practical consequences of such power loss are the need for larger, more expensive battery packs to perform engine cold cranking, slow charging in cold weather, restricted regenerative braking, and reduction of vehicle cruise range by as much as 40 per cent. Previous attempts to improve the low-temperature performance of lithium-ion batteries have focused on developing additives to improve the low-temperature behaviour of electrolytes, and on externally heating and insulating the cells. Here we report a lithium-ion battery structure, the ‘all-climate battery’ cell, that heats itself up from below zero degrees Celsius without requiring external heating devices or electrolyte additives. The self-heating mechanism creates an electrochemical interface that is favourable for high discharge/charge power. We show that the internal warm-up of such a cell to zero degrees Celsius occurs within 20 seconds at minus 20 degrees Celsius and within 30 seconds at minus 30 degrees Celsius, consuming only 3.8 per cent and 5.5 per cent of cell capacity, respectively. The self-heated all-climate battery cell yields a discharge/regeneration power of 1,061/1,425 watts per kilogram at a 50 per cent state of charge and at minus 30 degrees Celsius, delivering 6.4-12.3 times the power of state-of-the-art lithium-ion cells. We expect the all-climate battery to enable engine stop-start technology capable of saving 5-10 per cent of the fuel for 80 million new vehicles manufactured every year. Given that only a small fraction of the battery energy is used for self-heating, we envisage that the all-climate battery cell may also prove useful for plug-in electric vehicles, robotics and space exploration applications.

Lithium-ion battery structure that self-heats at low temperatures.

Science.gov (United States)

Wang, Chao-Yang; Zhang, Guangsheng; Ge, Shanhai; Xu, Terrence; Ji, Yan; Yang, Xiao-Guang; Leng, Yongjun

2016-01-28

Lithium-ion batteries suffer severe power loss at temperatures below zero degrees Celsius, limiting their use in applications such as electric cars in cold climates and high-altitude drones. The practical consequences of such power loss are the need for larger, more expensive battery packs to perform engine cold cranking, slow charging in cold weather, restricted regenerative braking, and reduction of vehicle cruise range by as much as 40 per cent. Previous attempts to improve the low-temperature performance of lithium-ion batteries have focused on developing additives to improve the low-temperature behaviour of electrolytes, and on externally heating and insulating the cells. Here we report a lithium-ion battery structure, the 'all-climate battery' cell, that heats itself up from below zero degrees Celsius without requiring external heating devices or electrolyte additives. The self-heating mechanism creates an electrochemical interface that is favourable for high discharge/charge power. We show that the internal warm-up of such a cell to zero degrees Celsius occurs within 20 seconds at minus 20 degrees Celsius and within 30 seconds at minus 30 degrees Celsius, consuming only 3.8 per cent and 5.5 per cent of cell capacity, respectively. The self-heated all-climate battery cell yields a discharge/regeneration power of 1,061/1,425 watts per kilogram at a 50 per cent state of charge and at minus 30 degrees Celsius, delivering 6.4-12.3 times the power of state-of-the-art lithium-ion cells. We expect the all-climate battery to enable engine stop-start technology capable of saving 5-10 per cent of the fuel for 80 million new vehicles manufactured every year. Given that only a small fraction of the battery energy is used for self-heating, we envisage that the all-climate battery cell may also prove useful for plug-in electric vehicles, robotics and space exploration applications.

Preliminary analysis of tank 241-C-106 dryout due to large postulated leak and vaporization

Energy Technology Data Exchange (ETDEWEB)

Piepho, M.G.

1995-03-01

At the Hanford site in SE Washington, there are 149 single-shell tanks containing radionuclide wastes in the form of liquids, sludges and salt cakes. One of the tanks, tank 241-C-106, is heated to the boiling point due to radionuclide decay (primarily Sr-90). Water is added to the tank, which is ventilated, in order to cool the tank. This analysis assumes that there is a hypothetical large leak at the bottom of Tank 241-C-106 which initiates the dryout of the tank. The time required for a tank to dryout after a leak is of interest for safety reasons. As a tank dries outs, its temperature is expected to greatly increase, which could affect the structural integrity of the concrete tank dome. Hence, it is of interest to know how fast the temperature in a leaky tank increases, so that mitigation procedures can be planned and implemented in a timely manner. The objective of the study was to determine how long it would take for tank 241-C-106 to reach 350 degrees Fahrenheit (about 177 degrees Centigrade) after a postulated large leak develops at the bottom center of the tank.

Heat-shock responses in two leguminous plants: a comparative study.

Science.gov (United States)

Ortiz, C; Cardemil, L

2001-08-01

Relative growth rates, basal and acclimated thermotolerance, membrane damage, fluorescence emission, and relative levels of free and conjugated ubiquitin and HSP70 were compared after 2 h of treatment at different temperatures between Prosopis chilensis and Glycine max (soybean), cv. McCall, to evaluate if the thermotolerance of these two plants was related to levels of accumulation of heat shock proteins. Seedlings of P. chilensis germinated at 25 degrees C and at 35 degrees C and grown at temperatures above germination temperature showed higher relative growth than soybean seedlings treated under the same conditions. The lethal temperature of both species was 50 degrees C after germination at 25 degrees C. However, they were able to grow at 50 degrees C after germination at 35 degrees C. Membrane damage determinations in leaves showed that P. chilensis has an LT(50) 6 degrees C higher than that of soybean. There were no differences in the quantum yield of photosynthesis (F(v)/F(m)), between both plants when the temperatures were raised. P. chilensis showed higher relative levels of free ubiquitin, conjugated ubiquitin and HSP70 than soybean seedlings when the temperatures were raised. Time-course studies of accumulation of these proteins performed at 40 degrees C showed that the relative accumulation rates of ubiquitin, conjugated ubiquitin and HSP70 were higher in P. chilensis than in soybean. In both plants, free ubiquitin decreased during the first 5 min and increased after 30 min of heat shock, conjugated ubiquitin increased after 30 min and HSP70 began to increase dramatically after 20 min of heat shock. From these data it is concluded that P. chilensis is more tolerant to acute heat stress than soybean.

Summer heat and mortality in New York City: how hot is too hot?

Science.gov (United States)

Metzger, Kristina B; Ito, Kazuhiko; Matte, Thomas D

2010-01-01

To assess the public health risk of heat waves and to set criteria for alerts for -excessive heat, various meteorologic metrics and models are used in different jurisdictions, generally without systematic comparisons of alternatives. We report such an analysis for New York City that compared maximum heat index with alternative metrics in models to predict daily variation in warm-season natural-cause mortality from 1997 through 2006. We used Poisson time-series generalized linear models and generalized additive models to estimate weather-mortality relationships using various metrics, lag and averaging times, and functional forms and compared model fit. A model that included cubic functions of maximum heat index on the same and each of the previous 3 days provided the best fit, better than models using maximum, minimum, or average temperature, or spatial synoptic classification (SSC) of weather type. We found that goodness of fit and maximum heat index-mortality functions were similar using parametric and nonparametric models. Same-day maximum heat index was linearly related to mortality risk across its range. The slopes at lags of 1, 2, and 3 days were flat across moderate values but increased sharply between maximum heat index of 95 degrees F and 100 degrees F (35-38 degrees C). SSC or other meteorologic variables added to the maximum heat index model moderately improved goodness of fit, with slightly attenuated maximum heat index-mortality functions. In New York City, maximum heat index performed similarly to alternative and more complex metrics in estimating mortality risk during hot weather. The linear relationship supports issuing heat alerts in New York City when the heat index is forecast to exceed approximately 95-100 degrees F. Periodic city-specific analyses using recent data are recommended to evaluate public health risks from extreme heat.

Modeling and Simulation of a Nuclear Fuel Element Test Section

Science.gov (United States)

Moran, Robert P.; Emrich, William

2011-01-01

"The Nuclear Thermal Rocket Element Environmental Simulator" test section closely simulates the internal operating conditions of a thermal nuclear rocket. The purpose of testing is to determine the ideal fuel rod characteristics for optimum thermal heat transfer to their hydrogen cooling/working fluid while still maintaining fuel rod structural integrity. Working fluid exhaust temperatures of up to 5,000 degrees Fahrenheit can be encountered. The exhaust gas is rendered inert and massively reduced in temperature for analysis using a combination of water cooling channels and cool N2 gas injectors in the H2-N2 mixer portion of the test section. An extensive thermal fluid analysis was performed in support of the engineering design of the H2-N2 mixer in order to determine the maximum "mass flow rate"-"operating temperature" curve of the fuel elements hydrogen exhaust gas based on the test facilities available cooling N2 mass flow rate as the limiting factor.

A nuclear reactor for district heating

International Nuclear Information System (INIS)

Bancroft, A.R.; Fenton, N.

1989-07-01

Global energy requirements are expected to double over the next 40 years. In the northern hemisphere, many countries consume in excess of 25 percent of their primary energy supply for building heating. Satisfying this need, within the constraints now being acknowledged for sustainable global development, provides an important opportunity for district heating. Fuel-use flexibility, energy and resource conservation, and reduced atmospheric pollution from acid gases and greenhouse gases, are important features offered by district heating systems. Among the major fuel options, only hydro-electricity and nuclear heat completely avoid emissions of combustion gases. To fill the need for an economical nuclear heat source, Atomic Energy of Canada Limited has designed a 10 MW plant that is suitable as a heat source within a network or as the main supply to large individual users. Producing hot water at temperatures below 100 degrees C, it incorporates a small pool-type reactor based on AECL's successful SLOWPOKE Research Reactor. A 2 MW prototype for the commercial unit is now being tested at the Whiteshell Nuclear Research Establishment in Manitoba. With capital costs of $7 million (Canadian), unit energy costs are projected to be $0.02/kWh for a 10 MW unit operating in a heating grid over a 30-year period. By keeping the reactor power low and the water temperature below 100 degrees C, much of the complexity of the large nuclear power plants can be avoided, thus allowing these small, safe nuclear heating systems to be economically viable

Objective correlate of subjective pain perception by contact heat-evoked potentials.

Science.gov (United States)

Granovsky, Yelena; Granot, Michal; Nir, Rony-Reuven; Yarnitsky, David

2008-01-01

The method of pain-evoked potentials has gained considerable acceptance over the last 3 decades regarding its objectivity, repeatability, and quantifiability. The present study explored whether the relationship between pain-evoked potentials and pain psychophysics obtained by contact heat stimuli is similar to those observed for the conventionally used laser stimulation. Evoked potentials (EPs) were recorded in response to contact heat stimuli at different body sites in 24 healthy volunteers. Stimuli at various temperatures were applied to the forearm (43 degrees C, 46 degrees C, 49 degrees C, and 52 degrees C) and leg (46 degrees C and 49 degrees C). The amplitudes of both components (N2 and P2) were strongly associated with the intensity of the applied stimuli and with subjective pain perception. Yet, regression analysis revealed pain perception and not stimulus intensity as the major contributing factor. A significant correlation was found between the forearm and the leg for both psychophysics and EPs amplitude. Contact heat can generate readily distinguishable evoked potentials on the scalp, consistent between upper and lower limbs. Although these potentials bear positive correlation with both stimulus intensity and pain magnitude, the latter is the main contributor to the evoked brain response.

Effects of different CMV-heat-inactivation-methods on growth factors in human breast milk.

Science.gov (United States)

Goelz, Rangmar; Hihn, Eva; Hamprecht, Klaus; Dietz, Klaus; Jahn, Gerhard; Poets, Christian; Elmlinger, Martin

2009-04-01

Preterm infants can inoculate virulent cytomegalovirus (CMV) through their mothers' raw breast milk. Complete virus inactivation is achieved only by heat treatment, but the effect on growth factors has never been assessed systematically. Insulin-like-growth-factor-1-, IGF-2-, insulin-like-growth-factor-binding-protein-2-, and IGFBP-3-concentrations were measured, before and after heating, in 51 breast-milk-samples from 28 mothers, and epidermal-growth-factor-concentrations in a subgroup of 35 samples from 22 mothers. Two heating methods were applied: Short-term (5 s) pasteurisation at 62, 65, and 72 degrees C, and long-term Holder-Pasteurisation (30 min) at 63 degrees C. IGF-1, IGF-2, IGFBP-2, and IGFBP-3 were measured by RIA, and EGF by ELISA. Heating for 30 min decreased significantly IGF-1 by 39.4%, IGF-2 by 9.9%, IGFBP-2 by 19.1%, and IGFBP-3 by 7.0%. In contrast, IGF-1, IGF-2, IGFBP-2, and IGFBP-3 were not altered significantly when using a short heating duration of 5 s, irrespective of the level of temperature, except for IGF-2 at 62 degrees C for 5 s (p = 0.041) and IGFBP-2 at 72 degrees C for 5 s (p = 0.025). Neither long- nor short-time heating methods changed the concentration of EGF. Only short heating methods (5 s, 62-72 degrees C) can preserve, almost completely, the concentrations of IGFs in human milk, whereas Holder-Pasteurization does not.

Effect of heat treatment changes on swelling treatment of coal; Sekitan no bojun shori sayo ni oyobosu netsushori henka no eikyo

Energy Technology Data Exchange (ETDEWEB)

Satsuka, T.; Mashimo, K.; Wainai, T. [Nihon University, Tokyo (Japan). College of Science and Technology

1996-10-28

Discussions were given on effects of heat treatment at relatively low temperatures as a pretreatment for coal liquefaction on coal swelling and hydrogenolysis reaction. Taiheiyo coal was heated to 200{degree}C for one hour as a pretreatment. The attempted heating methods consisted of four steps of rapid heating (6.7{degree}C/min)quenching (20{degree}C/min), rapid heating/natural cooling (0.7{degree}C/min), heating (1.0{degree}C/min)/quenching, and heating/natural cooling. The swelling treatment was composed of adding methanol benzene into heat treated coal, and leaving it at room temperature for 24 hours. The hydrogenolysis was carried out by using a tetralin solvent and at an initial hydrogen pressure of 20 kg/cm{sup 2} and a temperature of 350{degree}C and for a time of one hour. Hydrogenolysis conversion in the heat treated coal was found lower than that of the original coal because of generation of liquefaction inactive components due to thermal polymerization. When the heat treated coal is swollen by using the solvent, gas yield from the hydrogenolysis reaction decreased due to gas suppression effect, and the conversion was lower than that of the original coal. Heat treatment suggests densification of the coal structure. Swollen coal shows no conspicuous difference in the heat treatment methods against the hydrogenolysis due to the swelling effect. 3 refs., 5 figs., 1 tab.

Effect of heating strategy on power consumption and performance of a pilot plant anaerobic digester.

Science.gov (United States)

Espinosa-Solares, Teodoro; Valle-Guadarrama, Salvador; Bombardiere, John; Domaschko, Max; Easter, Michael

2009-05-01

The effect of heating strategy on power consumption and performance of a pilot plant anaerobic digester treating chicken litter, under thermophilic conditions, has been studied. Heating strategy was evaluated using three different spans (0.2 degrees C, 0.6 degrees C, and 1.0 degree C) for triggering the temperature control system from target temperature (56.7 degrees C). The hydraulic retention time in the pilot plant digester was in the range of 32 to 37 days, varying the total solids concentration fed from 5% to 6%. The results showed that under the experimental conditions, heating was the most energy-demanding process with 95.5% of the energy used. Increments up to 7.5% and 3.8%, respectively, on mechanical and heating power consumption, were observed as the span, for triggering the temperature control system from target temperature, was increased. Under the experimental conditions studied here, an increment of 30.6% on the global biodigester performance index was observed when a span of 1.0 degree C was compared to the one of 0.2 degrees C.

[Scanning electron microscopy of heat-damaged bone tissue].

Science.gov (United States)

Harsanyl, L

1977-02-01

Parts of diaphyses of bones were exposed to high temperature of 200-1300 degrees C. Damage to the bone tissue caused by the heat was investigated. The scanning electron microscopic picture seems to be characteristic of the temperature applied. When the bones heated to the high temperature of 700 degrees C characteristic changes appear on the periostal surface, higher temperatura on the other hand causes damage to the compact bone tissue and can be observed on the fracture-surface. Author stresses the importance of this technique in the legal medicine and anthropology.

Rapid PCR amplification using a microfluidic device with integrated microwave heating and air impingement cooling.

Science.gov (United States)

Shaw, Kirsty J; Docker, Peter T; Yelland, John V; Dyer, Charlotte E; Greenman, John; Greenway, Gillian M; Haswell, Stephen J

2010-07-07

A microwave heating system is described for performing polymerase chain reaction (PCR) in a microfluidic device. The heating system, in combination with air impingement cooling, provided rapid thermal cycling with heating and cooling rates of up to 65 degrees C s(-1) and minimal over- or under-shoot (+/-0.1 degrees C) when reaching target temperatures. In addition, once the required temperature was reached it could be maintained with an accuracy of +/-0.1 degrees C. To demonstrate the functionality of the system, PCR was successfully performed for the amplification of the Amelogenin locus using heating rates and quantities an order of magnitude faster and smaller than current commercial instruments.

[Modeling of processes of heat transfer in whole-body hyperthermia].

Science.gov (United States)

Kinsht, D N

2006-01-01

The method of whole-body hyperthermia in which the body temperature for a short time reaches values up to 43-44 degrees C holds currently much promise. However, at body temperatures above 42 degrees C, the risks associated with the hemodynamic instability and the appearance of arrhythmia in the patient increase. A model of heat transfer has been created to increase the efficiency and safety of the immersion-convectional method of whole-body hyperthermia. This model takes into account changes in the skin blood flow and the dynamics of pulse rate depending on body temperature. The model of heat transfer adequately reflects processes of heating of the organism and can form a basis for the calculation of distribution of heat inside the organism.

The correlation between heat-shock protein accumulation and persistence and chilling tolerance in tomato fruit

International Nuclear Information System (INIS)

Sabehat, A.; Weiss, D.; Lurie, S.

1996-01-01

Heating tomato fruit (Lycopersicon esculentum) for 48 h at 38 degrees C prevented chilling injury from developing after 21 d at 2 degrees C, whereas unheated fruit developed high levels of injury. Although the overall protein pattern as seen by Coomassie blue staining was similar from heated and unheated fruit, some high- and many low-molecular-mass proteins were observed in the heated fruit that were absent or present in reduced amounts in unheated fruit. When fruit were injected with [35S]methionine at harvest and then heated, they accumulated high levels of specific radiolabeled proteins that could still be detected after 21 d at 2 degrees C. If the fruit were held at 20 degrees C after heating, the label in the proteins declined rapidly and these fruit were also sensitive to chilling injury. Hsp70 antibody reacted more strongly with proteins from heated and chilled fruit than with proteins from chilled fruit. Hsp18.1 antibody reacted strongly with proteins from heated fruit but not with those from unheated fruit. A 23-kD protein, highly labeled in heated fruit but not in unheated fruit, had its amino terminus sequenced. To our knowledge, this is the first report showing a relationship between the persistence of heat-shock proteins and chilling tolerance in a plant tissue

Firefighting and Emergency Response Study of Advanced Composites Aircraft; Objective 1: Composite Material Damage in Minor Aircraft Fires

Science.gov (United States)

2013-05-18

C-15 XGM 736 13,423 61.7 C-16 XGM 746 14,080 59.7 C4-13 XGV 451 12,618 47.5 C4-14 XGV 431 11,994 45.5 C4-15 XGV 416 11,333 48.8 * XGV... Fahrenheit % percent 1-D one-dimensional 3-D three-dimensional  density H heat generated/absorbed  the Stephan-Boltzmann constant  emissivity με

Direct contact heat transfer characteristics between melting alloy and water

International Nuclear Information System (INIS)

Kinoshita, Izumi; Nishi, Yoshihisa; Furuya, Masahiro

1995-01-01

As a candidate for an innovative steam generator for fast breeder reactors, a heat exchanger with direct contact heat transfer between melting alloy and water was proposed. The evaluation of heat transfer characteristics of this heat exchanger is one of the research subjects for the design and development of the steam generator. In this study, the effect of the pressure on heat transfer characteristics and the required degree of superheating of melting alloy above water saturation temperature are evaluated during the direct contact heat transfer experiment by injecting water into Wood's alloy. In the experiment, the pressure, the temperature of the Wood's alloy, the flow rate of feed water, and the depth of the feed water injection point are varied as parameters. As a result of the experiment, the product of the degree of Wood's alloy superheating above water saturation temperature and the depth of the feed water injection point is constant for each pressure. This constant increases as the pressure rises. (author)

Urban physiology: city ants possess high heat tolerance.

Directory of Open Access Journals (Sweden)

Michael J Angilletta

Full Text Available Urbanization has caused regional increases in temperature that exceed those measured on a global scale, leading to urban heat islands as much as 12 degrees C hotter than their surroundings. Optimality models predict ectotherms in urban areas should tolerate heat better and cold worse than ectotherms in rural areas. We tested these predications by measuring heat and cold tolerances of leaf-cutter ants from South America's largest city (São Paulo, Brazil. Specifically, we compared thermal tolerances of ants from inside and outside of the city. Knock-down resistance and chill-coma recovery were used as indicators of heat and cold tolerances, respectively. Ants from within the city took 20% longer to lose mobility at 42 degrees C than ants from outside the city. Interestingly, greater heat tolerance came at no obvious expense of cold tolerance; hence, our observations only partially support current theory. Our results indicate that thermal tolerances of some organisms can respond to rapid changes in climate. Predictive models should account for acclimatory and evolutionary responses during climate change.

Electrical energy use in different heating systems for early weaned piglets

Energy Technology Data Exchange (ETDEWEB)

Sarubbi, J. [Federal Univ. of Santa Maria, Palmeira das Missoes, RS (Brazil). Dept. of Animal Science; Campinas State Univ., Sao Paulo (Brazil). College of Agricultural Engineering; Rossi, L.A.; Moura, D.J.; Oliveira, R.A.; David, E. [Campinas State Univ., Sao Paulo (Brazil). College of Agricultural Engineering

2010-07-01

This study compared the electrical energy use and thermal comfort conditions associated with 3 heating technologies used in piglet farms. Heating systems for piglets in nursery and farrowing can be improved to conserve energy without affecting the welfare of the animals. The evaluation was conducted at a commercial farm in a subtropical climate area of Brazil. Each treatment involved 150 weaned piglets at 21 days-old. The systems were designed to keep the piglets at 28 to 30 degrees C for 14 days. Suspended electrical resistors, heated floors and convection heating were the 3 heating technologies examined during this study which evaluated the electrical energy consumption, maximum power demand requirements and dry-bulb temperature. The study also assessed the specific consumption in terms of kWh/kg of live produced body mass as well as the efficiency of heating system in terms of degrees C per cubic metre of air. In terms of electrical energy use, the best heating system was the heated floor. However, the electrical resistance heating system was the best in terms of thermal comfort.

Management Plan: Demonstration testing and evaluation of in situ soil heating

International Nuclear Information System (INIS)

Dev, H.

1993-01-01

In this project IITRI will demonstrate an in situ soil heating technology for the removal of hazardous organic contaminants present in the soil. In Situ heating will be accomplished by the application of 60 Hz AC power to the soil. The soil will be heated to a temperature of about 90 degree C. This technology is suited for the removal of those organic compounds which have a normal boiling point in the range of 100 degree to 210 degree C, or else for those which exhibit a pure component vapor pressure of at least 10 mm Hg in the 90 degree to 100 degree C temperature range. For example, perchloroethylene, dichlorobenzene, trichlorobenzene, etc. may be removed by in situ AC heating. It is planned to demonstrate the technology by heating approximately 400 tons of soil in the K-1070 Classified Burial Ground located at DOE's K-25 Site located in Oak Ridge, TN. It is estimated that the heating portion of the demonstration will take approximately 3 weeks at an average power input rate of 150 to 175 kill. IITRI expects to spend considerable time in the front end reviewing site characteristics, preparing detail design, developing Health and Safety Plans and other documents needed to obtain regulatory approval for the demonstration, arranging for site sampling, infrastructure development and document preparation. It is anticipated that site activities will begin in approximately 5 to 6 months. This contract was signed on September 30, 1993. IITRI started work on it in October 1993. It is planned to complete the demonstration and submit approved final reports by September 30, 1994. This project has 12 tasks and four major milestones. The major milestones and their planned completion dates are presented

Magnetoresistance effect of heat generation in a single-molecular spin-valve

International Nuclear Information System (INIS)

Jiang, Feng; Yan, Yonghong; Wang, Shikuan; Yan, Yijing

2016-01-01

Based on non-equilibrium Green's functions' theory and small polaron transformation's technology, we study the heat generation by current through a single-molecular spin-valve. Numerical results indicate that the variation of spin polarization degree can change heat generation effectively, the spin-valve effect happens not only in electrical current but also in heat generation when Coulomb repulsion in quantum dot is smaller than phonon frequency and interestingly, when Coulomb repulsion is larger than phonon frequency, the inverse spin-valve effect appears by sweeping gate voltage and is enlarged with bias increasing. The inverse spin-valve effect will induce the unique heat magnetoresistance effect, which can be modulated from heat-resistance to heat-gain by gate voltage easily. - Highlights: • Spin-valve effect of heat generation happens when Coulomb repulsion in quantum dot is less than phonon frequency. • When Coulomb repulsion is larger than phonon frequency, inverse spin-valve effect appears and is enlarged with bias increasing. • The variation of spin polarization degree can change heat generation effectively. • The heat magnetoresistance can be modulated from heat-resistance to heat-gain by gate voltage easily.

Field evaluation and assessment of thermal energy storage for residential space heating

Science.gov (United States)

Hersh, H. N.

1982-02-01

A data base was developed based on two heating seasons and 45 test and 30 control homes in Maine and Vermont. Based on first analysis of monitored temperatures and electrical energy used for space heating, fuel bills and reports of users and utilities, the technical performance of TES ceramic and hydronic systems is deemed to be technically satisfactory and there is a high degree of customer acceptance and positive attitudes towards TES. Analysis of house data shows a high degree of variability in electric heat energy demand for a given degree-day. An analysis is underway to investigate relative differences in the efficiency of electricity utilization of storage and direct heating devices. The much higher price of storge systems relative to direct systems is an impediment to market penetration. A changing picture of rate structures may encourage direct systems at the expense of storage systems.

Effects of rolling on single-phase water forced convective heat transfer characteristics

International Nuclear Information System (INIS)

Guo Yanming; Gao Puzhen; Huang Zhen

2010-01-01

A series of single-phase forced circulation tests in a vertical tube with rolling motion were performed in order to investigate effects of rolling motion on thermal-hydraulic characteristics. The amplitudes of the rolling motion in the tests were 10 degree, 15 degree and 20 degree. The rolling periods were 7.5 s, 10 s, 15 s and 20 s. The Reynolds number was from 6000 to 15000. Heat transfer in the test tube is bated by the rolling motion. As the test-bed rolling more acutely, the heat transfer coefficient of the test tube becomes smaller when the mass flow rate in the test tube is a constant. The heat transfer coefficient calculated by the formula which is for stable state doesn't fit very well with that from experiments. At last a formula for calculating heat transfer in rolling motion was introduced. (authors)

Practical and efficient magnetic heat pump

Science.gov (United States)

Brown, G. V.

1978-01-01

Method for pumping heat magnetically at room temperature is more economical than existing refrigeration systems. Method uses natural magneto-thermal effect of gadolinium metal to establish temperature gradient across length of tube. Regenerative cyclic process in which gadolinium sample is magnetized and gives off heat at one end of tube, and then is demagnetized at other end to absorb heat has established temperature gradients of 144 degrees F in experiments near room temperature. Other materials with large magnetothermal effects can be used below room temperature. Possible commercial applications include freeze-drying and food processing, cold storage, and heating and cooling of buildings, plants, and ships.

Study of temperature effect on the physical properties of ilmenite-serpentine heat resistant concrete radiation shields

International Nuclear Information System (INIS)

Kany, A.M.I.; EL-Fouly, M.M.; EL-Gohary, M.I.; Makatious, A.S.; Kamal, S.M.

1990-01-01

A series of experimental studies have been carried out to determine the change in unit weigh, compressive strength, water content and neutron macroscopic cross section of a new type of concrete shields made from egyptian ilmenite and serpentine ores when heated for long period at temperatures up to 600 degree C. Results show that the unit weight of the cure concrete has a value of 2.98 Ton/M 3 and decreases with increasing temperature, while the compressive strength reaches a maximum value of 19 Ton/M 2 at 100 degree C. The differential thermal analysis (D.T.A.) of this concrete shows three endothermic peaks at 100 degree C, 48 degree C and 740 degree C. Also, the thermogravimetry analysis (T.G.A.) shows that the cure concrete retains about 11% water content of the total sample weigh and still retains 4.5% of its initial value when heated for long period at 600 degree C. Results also show that the neutron macroscopic cross section (for neutrons of energies < 1 MeV) of the ilmenite-serpentine heat resistant concrete decreases to 18.6% of its initial value after heating to 600 degree C

A study on pre-heat conditions in equivalent-dose estimation of holocene loess using single-aliquot regenerative-dose (SAR) protocol

International Nuclear Information System (INIS)

Jia Yaofeng; Huang Chunchang; Pang Jiangli; Lu Xinwei; Zhang Xu

2007-01-01

Through various arrangements of pre-heat and cut-heat temperatures in the equivalent-dose estimation of Holocene loess using a Double-SAR dating protocol, the paper estimated the equivalent-doses from several loess samples by application of IRSL and Post-IR OSL signals, respectively. The measured results present that the equivalent-dose depends on the heat temperature, especially depends on the cut-heat temperature, showing the equivalent-dose increases with the cut-heat temperature; a plateau of equivalent-dose appears at the 200-300 degree C preheat temperatures and the 200-240 degree C cut-heat temperatures, furthermore, the equivalent-doses estimated by IRSL and Post-IR OSL signals respectively are close to each other, which resulted from the similar sensitivity change directions of optical stimulated signals and their smaller change ranges in the measurement cycles using the various temperatures of pre-heat and cut-heat. This suggests that the 200-300 degree C pre-heat temperatures and the 200-240 degree C cut-heat temperatures are fit for dating young Holocene loess samples. (authors)

Effect of heat treatment on microstructure and mechanical properties of PIP-SiC/SiC composites

Energy Technology Data Exchange (ETDEWEB)

Zhao, Shuang, E-mail: zhsh6007@126.com [Key Laboratory of Advanced Ceramic Fibres and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China); School of Mechanical, Aerospace, and Civil Engineering, University of Manchester, Manchester M13 9PL (United Kingdom); Zhou, Xingui; Yu, Jinshan [Key Laboratory of Advanced Ceramic Fibres and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China); Mummery, Paul [School of Mechanical, Aerospace, and Civil Engineering, University of Manchester, Manchester M13 9PL (United Kingdom)

2013-01-01

Continuous SiC fibre reinforced SiC matrix composites (SiC/SiC) have been studied as materials for heat resistant and nuclear applications. Thermal stability is one of the key issues for SiC/SiC composites. In this study, 3D SiC/SiC composites are fabricated via the polymer impregnation and pyrolysis (PIP) process, and then heat treated at 1400 Degree-Sign C, 1600 Degree-Sign C and 1800 Degree-Sign C in an inert atmosphere for 1 h, respectively. The effect of heat treatment on microstructure and mechanical properties of the composites is investigated. The results indicate that the mechanical properties of the SiC/SiC composites are significantly improved after heat treatment at 1400 Degree-Sign C mainly because the mechanical properties of the matrix are greatly improved due to crystallisation. With the increasing of heat treatment temperature, the properties of the composites are conversely decreased because of severe damage of the fibres and the matrix.

Experimental study of heat transfer performance in a flattened AGHP

International Nuclear Information System (INIS)

Tao Hanzhong; Zhang Hong; Zhuang Jun; Jerry Bowman, W.

2008-01-01

Round mini-axial grooved heat pipes (AGHP) with a diameter of 6 mm and a length of 210 mm were pressed into flattened heat pipes with a thickness of 3.5 mm, 3 mm, 2.5 mm and 2 mm, respectively. The article measured the heat transfer limit, thermal resistance and evaporation heat transfer coefficient of the said AGHPs and analyzed and studied the result. The result indicates: the heat transfer limit decreased with the increase of flattening degree. The heat transfer limit of the 2 mm thick flattened AGHP was only 1/4 of that of the φ 6 mm round AGHP. The thermal resistance of the 3.5-2.5 mm thick AGHPs basically maintained stable at around 0.08 deg. C/W, while the thermal resistance of the 2 mm thick flattened AGHP increased obviously. The variation of the heat transfer coefficient in evaporator section with the change of flattening degree follows a similar rule to the variation of thermal resistance. This article serves as a reference to understanding the heat transfer performance of mini AGHP and to electronic cooling design of AGHP

Use of a commercial heat transfer code to predict horizontally oriented spent fuel rod surface temperatures

International Nuclear Information System (INIS)

Wix, S.D.; Koski, J.A.

1993-03-01

Radioactive spent fuel assemblies are a source of hazardous waste that will have to be dealt with in the near future. It is anticipated that the spent fuel assemblies will be transported to disposal sites in spent fuel transportation casks. In order to design a reliable and safe transportation cask, the maximum cladding temperature of the spent fuel rod arrays must be calculated. A comparison between numerical calculations using commercial thermal analysis software packages and experimental data simulating a horizontally oriented spent fuel rod array was performed. Twelve cases were analyzed using air and helium for the fill gas, with three different heat dissipation levels. The numerically predicted temperatures are higher than the experimental data for all levels of heat dissipation with air as the fill gas. The temperature differences are 4 degree C and 23 degree C for the low heat dissipation and high heat dissipation, respectively. The temperature predictions using helium as a fill gas are lower for the low and medium heat dissipation levels, but higher at the high heat dissipation. The temperature differences are 1 degree C and 6 degree C for the low and medium heat dissipation, respectively. For the high heat dissipation level, the temperature predictions are 16 degree C higher than the experimental data. Differences between the predicted and experimental temperatures can be attributed to several factors. These factors include experimental uncertainty in the temperature and heat dissipation measurements, actual convection effects not included in the model, and axial heat flow in the experimental data. This work demonstrates that horizontally oriented spent fuel rod surface temperature predictions can be made using existing commercial software packages. This work also shows that end effects will be increasingly important as the amount of dissipated heat increases

Army Communicator. Volume 32, Number 2, Spring 2007

Science.gov (United States)

2007-01-01

Strategic Command, Defense Information Systems Agency, or at Combatant Command or Army Major Com- mand staffs. Although there is no yellow brick road of...given, set in stone by the temperature of the low noise amplifier, which is generally ambient air temperature, about 70 degrees Fahrenheit. So that...business innovation research SIGINT – signals intelligence SME – superconducting microelec- tronics SPAWAR – Space and Naval War- fare Systems Command

Influence of Hot-Working Conditions on High-Temperature Properties of a Heat-Resistant Alloy

Science.gov (United States)

Ewing, John F; Freeman, J W

1957-01-01

The relationships between conditions of hot-working and properties at high temperatures and the influence of the hot-working on response to heat treatment were investigated for an alloy containing nominally 20 percent molybdenum, 2 percent tungsten, and 1 percent columbium. Commercially produced bar stock was solution-treated at 2,200 degrees F. to minimize prior-history effects and then rolled at temperatures of 2,200 degrees, 2,100 degrees, 2,000 degrees, 1,800 degrees, and 1,600 degrees F. Working was carried out at constant temperature and with incremental decreases in temperature simulating a falling temperature during hot-working. In addition, a few special repeated cyclic conditions involving a small reduction at high temperature followed by a small reduction at a low temperature were used to study the possibility of inducing very low strengths by the extensive precipitation accompanying such properties. Most of the rolling was done in open passes with a few check tests being made with closed passes. Heat treatments at both 2,050 degrees and 2,200 degrees F. subsequent to working were used to study the influence on response to heat treatment.

Device for measuring a burnup degree

International Nuclear Information System (INIS)

Ito, Toshiaki; Goto, Seiichiro

1979-01-01

Purpose: To measure the burnup degree at high efficiency and accuracy. Constitution: The outer metal wall of fuel assemblies is heated under gamma radiation with long half life gamma rays in inverse proportion to the burnup degree and issues infrared radiation in proportion to the intensity of the gamma rays. An image pick-up tube is opposed to one surface of the fuel assemblies to detect the radiated infrared rays. Since the output signal from the pick-up tube is subjected to the absorptive damping by the distance between the pick-up tube and the fuel assembly, as well as water filled in the gap therebetween, it is corrected through a main amplifier comprising a signal correction circuit composed of a characteristic section inverse to the absorption property and a characteristic section inverse to the square of the distance. The corrected output signal is displayed on a display unit such as CRT or recorded in a film or a magnetic tape. (Furukawa, Y.)

An analysis of geothermal heating and engineering cost in Tianjin, China

International Nuclear Information System (INIS)

Wang, W.

1990-01-01

Tianjin is a region with fairly rich low-temperature geothermal resources. Its climate and soaring price of raw coals have made geo heating in Tianjin develop rapidly over the past 5 years. The types of heating systems fall into 3 categories and the primary factors for using temperature drop are 5. According to economical analysis, the optimal discharge temperature in the space heating is about 43 degrees C and the minimum discharge temperature 35 degrees C approximately. This paper reports that an analysis of a typical engineering costs involved shows that the advantages of geo space heating are not notable when compared with burning coals. However, to reduce air pollution, the state and general public are ready to support the development of such geothermal wells as deep as 3,000 m for space heating irrespective of their sole engineering costs

Heat resistance of Escherichia coli O157:H7 in apple juice.

Science.gov (United States)

Splittstoesser, D F; McLellan, M R; Churey, J J

1996-03-01

The objective was to determine the effect of cider composition on the heat resistance of Escherichia coli O157:H7. The average D52 value in a model Empire apple juice was 18 min with a z value of 4.8 degrees C. Increasing the Brix from 11.8 to 16.5 degrees had no effect on thermal resistance, while increasing L-malic acid from 0.2 to 0.8%, or reducing the pH from 4.4 to 3.6 sensitized the cells to heat. The greatest effect on heat resistance was afforded by the preservatives benzoic and sorbic acids: D50 values in ciders containing 1,000 mg/l were 5.2 min in the presence of sorbic acid and only 0.64 min in the presence of benzoic acid. Commercial apple juice concentrates yielded lower numbers of survivors than single-strength juices even though their higher sugar concentrations of about 46 degrees Brix increased heat resistance.

Heat stroke in Hajj ceremonies

Directory of Open Access Journals (Sweden)

Sadr Sh

1995-04-01

Full Text Available Three hundred and seventy seven patients with different degrees of heat stroke were treated by the haji medical team of the Islamic Republic of Iran in 1371 (1992. Studies were carried out on sex of the patients, time and intensity of occurance and the vital signs after a medical examination. The most important method of treatment employed for intense heat stroke was iced bath. This procedure leads to 64.5% of patients being treated in te specific heat stroke unit and 35% were sent to a general hospital ward for furthur treatment. Morbidity and mortality were seen in less than 0.5% of the patients.

Tissue physiology and the response to heat

DEFF Research Database (Denmark)

Horsman, Michael Robert

2006-01-01

physiological effects should occur in normal tissues, such combination therapies must be carefully applied. Heating tumours to higher temperatures typically causes a transient increase in perfusion during heating, followed by vascular collapse which if sufficient will increase tumour necrosis. The speed...... and degree of vascular collapse is dependent on heating time, temperature and tumour model used. Such vascular collapse generally occurs at temperatures that cause a substantial blood flow increase in certain normal tissues, thus preferential anti-tumour effects can be achieved. The tumour vascular supply...... can also be exploited to improve the response to heat. Decreasing blood flow, using transient physiological modifiers or longer acting vascular disrupting agents prior to the initiation of heating, can both increase the accumulation of physical heat in the tumour, as well as increase heat sensitivity...

Heat shock and thermotolerance of Escherichia coli O157:H7 in a model beef gravy system and ground beef.

Science.gov (United States)

Juneja, V K; Klein, P G; Marmer, B S

1998-04-01

Duplicate beef gravy or ground beef samples inoculated with a suspension of a four-strain cocktail of Escherichia coli O157:H7 were subjected to sublethal heating at 46 degrees C for 15-30 min, and then heated to a final internal temperature of 60 degrees C. Survivor curves were fitted using a linear model that incorporated a lag period (TL), and D-values and 'time to a 4D inactivation' (T4D) were calculated. Heat-shocking allowed the organism to survive longer than non-heat-shocked cells; the T4D values at 60 degrees C increased 1.56- and 1.50-fold in beef gravy and ground beef, respectively. In ground beef stored at 4 degrees C, thermotolerance was lost after storage for 14 h. However, heat-shocked cells appeared to maintain their thermotolerance for at least 24 h in ground beef held to 15 or 28 degrees C. A 25 min heat shock at 46 degrees C in beef gravy resulted in an increase in the levels of two proteins with apparent molecular masses of 60 and 69 kDa. These two proteins were shown to be immunologically related to GroEL and DnaK, respectively. Increased heat resistance due to heat shock must be considered while designing thermal processes to assure the microbiological safety of thermally processed foods.

Heat exposure and socio-economic vulnerability as synergistic factors in heat-wave-related mortality

International Nuclear Information System (INIS)

Rey, Gregoire; Fouillet, Anne; Bessemoulin, Pierre; Frayssinet, Philippe; Dufour, Anne; Jougla, Eric; Hemon, Denis

2009-01-01

Heat waves may become a serious threat to the health and safety of people who currently live in temperate climates. It was therefore of interest to investigate whether more deprived populations are more vulnerable to heat waves. In order to address the question on a fine geographical scale, the spatial heterogeneity of the excess mortality in France associated with the European heat wave of August 2003 was analysed. A deprivation index and a heat exposure index were used jointly to describe the heterogeneity on the Canton scale (3,706 spatial units). During the heat wave period, the heat exposure index explained 68% of the extra-Poisson spatial variability of the heat wave mortality ratios. The heat exposure index was greater in the most urbanized areas. For the three upper quintiles of heat exposure in the densely populated Paris area, excess mortality rates were twofold higher in the most deprived Cantons (about 20 excess deaths/100,000 people/day) than in the least deprived Cantons (about 10 excess deaths/100,000 people/day). No such interaction was observed for the rest of France, which was less exposed to heat and less heterogeneous in terms of deprivation. Although a marked increase in mortality was associated with heat wave exposure for all degrees of deprivation, deprivation appears to be a vulnerability factor with respect to heat-wave-associated mortality.

Improvements in or relating to heat exchangers

International Nuclear Information System (INIS)

Taylor, P.A.

1978-01-01

According to the present invention there is provided a method of producing superheated steam by use of the heat in liquid sodium, in which liquid sodium is caused to flow through a space having boundaries of which no part is common with the boundaries of a space in which vapour is produced, a fluid that is inert to sodium is heated by heat exchange at the boundaries of the space through which the liquid sodium flows and serves as the heating medium for the production of vapour, and the vapour is subsequently heated to the final degree of superheat by heat exchange with liquid sodium in a space that has a common boundary with a space through which liquid sodium is passed. (U.K.)

Alterations in reproductive hormones during heat stress in dairy cattle

African Journals Online (AJOL)

Alterations in reproductive hormones during heat stress in dairy cattle. ... Heat stress reduces the degree of dominance of the selected follicle and this can be seen as reduced steroidogenic capacity of its theca and ... from 32 Countries:.

Enhancement of parathion toxicity to quail by heat and cold exposure

Science.gov (United States)

Rattner, B.A.; Becker, J.M.; Nakatsugawa, T.

1987-01-01

Effects of ambient temperature on the acute oral toxicity of parathion were investigated in Japanese quail (Coturnix japonica) maintained at thermoneutral temperature (26.degree. C) or exposed to elevated (37.degree. C) or reduced (4.degree. C) temperatures commonly encountered by free-ranging wild birds. Based upon estimates of the median lethal dosage, there was up to a two-fold enhancement of parathion toxicity in birds chronically exposed to heat or cold. Twenty-four hours after administration of a low dosage (4 mg/kg body wt, po), there was markedly greater cholinesterase inhibition in surviving heat-exposed quail compared with those reared at 26.degree. C (e.g., brain acetylcholinesterase depression of 42% versus 12%). There were no differences in hepatic activities of parathion oxidase, paraoxonase, or paraoxon deethylase which could account for greater toxicity to chronically heat-exposed birds. In contrast, 4 mg parathion/kg wt elicited less plasma cholinesterase inhibition in cold-exposed quail compared to thermoneutral controls (e.g., birds is substantially influenced by environmental temperature.

Confidence intervals for modeling anthocyanin retention in grape pomace during nonisothermal heating.

Science.gov (United States)

Mishra, D K; Dolan, K D; Yang, L

2008-01-01

Degradation of nutraceuticals in low- and intermediate-moisture foods heated at high temperature (>100 degrees C) is difficult to model because of the nonisothermal condition. Isothermal experiments above 100 degrees C are difficult to design because they require high pressure and small sample size in sealed containers. Therefore, a nonisothermal method was developed to estimate the thermal degradation kinetic parameter of nutraceuticals and determine the confidence intervals for the parameters and the predicted Y (concentration). Grape pomace at 42% moisture content (wb) was heated in sealed 202 x 214 steel cans in a steam retort at 126.7 degrees C for > 30 min. Can center temperature was measured by thermocouple and predicted using Comsol software. Thermal conductivity (k) and specific heat (C(p)) were estimated as quadratic functions of temperature using Comsol and nonlinear regression. The k and C(p) functions were then used to predict temperature inside the grape pomace during retorting. Similar heating experiments were run at different time-temperature treatments from 8 to 25 min for kinetic parameter estimation. Anthocyanin concentration in the grape pomace was measured using HPLC. Degradation rate constant (k(110 degrees C)) and activation energy (E(a)) were estimated using nonlinear regression. The thermophysical properties estimates at 100 degrees C were k = 0.501 W/m degrees C, Cp= 3600 J/kg and the kinetic parameters were k(110 degrees C)= 0.0607/min and E(a)= 65.32 kJ/mol. The 95% confidence intervals for the parameters and the confidence bands and prediction bands for anthocyanin retention were plotted. These methods are useful for thermal processing design for nutraceutical products.

SLOWPOKE: heating reactors in the urban environment

International Nuclear Information System (INIS)

Hilborn, J.W.; Lynch, G.F.

1988-06-01

Since global energy requirements are expected to double over the next 40 years, nuclear heating could become as important as nuclear electricity generation. To fill that need, AECL has designed a 10 MW nuclear heating plant for large buildings. Producing hot water at temperatures below 100 degrees Celsius, it incorporates a small pool-type reactor based on the successful SLOWPOKE Research Reactor. A 2 MW prototype is now being tested at the Whiteshell Nuclear Research Establishment in Manitoba, and the design of a 10 MW commercial unit is well advanced. With capital costs in the range $5 million to $7 million, unit energy costs could be as low as $0.02 per kWh, for a unit operating at 50% load factor over a 25-year period. By keeping the reactor power low and the water temperature below 100 degrees Celsius, much of the complexity of the large nuclear power plants can be avoided, thus allowing these small, safe, nuclear heating systems to be economically viable

Floor heating systems

Energy Technology Data Exchange (ETDEWEB)

Radtke, U

1984-02-01

The question of whether PPC- and VPE-floor heating pipes can endure damage when incompletely imbedded in the floor finish is investigated in an experimental setup. An expansion of the pipe, caused by a temperature increase from 20/sup 0/C to 50/sup 0/C was measured and considered too small to deduce the degree of danger from the damage.

The effects of acclimatization on blood clotting parameters in exertional heat stress.

Science.gov (United States)

Vesić, Zoran; Vukasinović-Vesić, Milica; Dincić, Dragan; Surbatović, Maja; Radaković, Sonja S

2013-07-01

Exertional heat stress is a common problem in military services. Considering the coagulation abnormalities are of major importance in development of severe heat stroke, we wanted to examine changes in hemostatic parameters in soldiers during exertional heat stress test as well as the effects of a 10-day passive or active acclimatization in a climatic chamber. A total of 40 male soldiers with high aerobic capacity performed exertional heat stress test (EHST) either in cool [20 degrees C, 16 degrees C wet bulb globe temperature (WBGT)], or hot (40 degrees C, 29 degrees C, (WBGT) environment, unacclimatized (U) or after 10 days of passive (P) or active (A) acclimatization. Physiological strain was measured by tympanic temperatures (Tty) and heart rates (HR). Platelet count (PC), antithrombin III (AT), and prothrombin time (PT) were assessed in blood samples collected before and immediately after the EHST. EHST in hot conditions induced physiological heat stress (increase in Tty and HR), with a significant increase in prothrombin time in the groups U and A. Platelet counts were significantly higher after the EHST compared to the basic levels in all the investigated groups, regardless environmental conditions and acclimatization state. Antithrombin levels were not affected by EHST whatsoever. In the trained soldiers, physiological heat stress caused mild changes in some serum parameters of blood clotting such as prothrombin time, while others such as antithrombin levels were not affected. Platelet counts were increased after EHST in all groups. A 10-day passive or active acclimatization in climatic chamber showed no effect on parameters investigated.

Study on Heat Transfer Characteristics of One Side Heated Vertical Channel Applied as Vessel Cooling System

International Nuclear Information System (INIS)

Kuriyama, Shinji; Takeda, Tetsuaki; Funatani, Shumpei

2014-01-01

The inherent properties of the Very-High-Temperature Reactor facilitate the design of the VHTR with high degree of passive safe performances, compared to other type of reactors. However; it is still not clear if the VHTR can maintain a passive safe function during the severe accident, or what would be a design criterion to guarantee the VHTR with the high degree of passive safe performances during the accidents. In the Very High Temperature Reactor (VHTR) which is a next generation nuclear reactor system, ceramics and graphite are used as a fuel coating material and a core structural material, respectively. Even if the depressurization accident occurs and the reactor power goes up instantly, the temperature of the core will change slowly. This is because the thermal capacity of the core is so large. Therefore, the VHTR system can passively remove the decay heat of the core by natural convection and radiation from the surface of the reactor pressure vessel (RPV). This study is to develop the passive cooling system for the VHTR using the vertical channel inserting porous materials. The objective of this study is to investigate heat transfer characteristics of natural convection of a one-side heated vertical channel inserting the porous materials with high porosity. In order to obtain the heat transfer and fluid flow characteristics of a vertical channel inserting porous material, we have also carried out a numerical analysis using the commercial CFD code. From the analytical results obtained in the natural convection cooling, an amount of removed heat enhanced inserting the copper wire. It was found that an amount of removed heat inserting the copper wire (porosity = 0.9972) was about 10% higher than that without the copper wire. This paper describes a thermal performance of the one-side heated vertical channel inserting copper wire with high porosity. (author)

Slowpoke - a new Canadian heat source

International Nuclear Information System (INIS)

Bancroft, A.R.; Lynch, G.F.; Ohta, M.M.

1987-07-01

Atomic Energy of Canada Limited now has a new product, the SLOWPOKE Energy System, that provides low temperature heat suitable for building and process heating. The SLOWPOKE Energy System is sized to deliver up to 10 megawatts of hot water at up to 90 degrees C, appropriate for large buildings and industrial processes. It is designed for operation without the full-time attendance of dedicated staff and, because of its inherent safety, for siting close to users. At less than 2 cents/kWh, the heat is competitive with oil, gas and electricity in most regions of Canada and the world

Range Extension Opportunities While Heating a Battery Electric Vehicle

Energy Technology Data Exchange (ETDEWEB)

Lustbader, Jason A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rugh, John P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Titov, Eugene V [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Meyer, John [Hanon Systems; Agathocleous, Nicos [Hanon Systems; Vespa, Antonio [Hyundai-Kia America Technical Center Inc.

2018-04-03

The Kia Soul battery electric vehicle (BEV) is available with either a positive temperature coefficient (PTC) heater or an R134a heat pump (HP) with PTC heater combination (1). The HP uses both ambient air and waste heat from the motor, inverter, and on-board-charger (OBC) for its heat source. Hanon Systems, Hyundai America Technical Center, Inc. (HATCI) and the National Renewable Energy Laboratory jointly, with financial support from the U.S. Department of Energy, developed and proved-out technologies that extend the driving range of a Kia Soul BEV while maintaining thermal comfort in cold climates. Improved system configuration concepts that use thermal storage and waste heat more effectively were developed and evaluated. Range extensions of 5%-22% at ambient temperatures ranging from 5 degrees C to -18 degrees C were demonstrated. This paper reviews the three-year effort, including test data of the baseline and modified vehicles, resulting range extension, and recommendations for future actions.

An evaluation of the potential of combination processes involving heat and irradiation for food preservation

International Nuclear Information System (INIS)

Shamsuzzaman, K.; Payne, B.; Cole, L.; Goodwin, M.; Borsa, J.

1989-11-01

Effects of combined heating and gamma radiation on Clostridium sporogenes spores and Salmonella seftenberg were examined. The order in which irradiation and heat were applied had a profound effect on the survival of the organisms. Heating of C.sporogenes spores at 95 degrees Celsius had very little effect on their sensitivity to subsequent irradiation, but irradiation of the spores at 0 degrees Celsius increased their sensitivity to subsequent heat treatment and thus reduced their heat D 10 values (time required to activate the spores to 10% of their initial number). This radiation-induced heat sensitivity increased with the increase in radiation dose. The Z values (change in temperature required for a tenfold change in D 10 values) of the spores were found to increase with the increase in pre-irradiation dose. Radiation-induced heat sensitivity was found to persist for at least 35 days in spores irradiated in frozen or freeze-dried states in distilled water or in phosphate buffer suspensions, and for at least 14 days in a number of food slurries. In phosphate buffer and nutrient broth suspensions, the radiation-heat synergism decreased with increasing pH of the media from pH 4.7 to pH 7.5. However, the effect of pH on synergism was less pronounced in spores suspended in some food slurries. Preliminary results indicate that pre-irradiation of S. senftenberg at 0.5 kGy did not change the heat sensitivity of this organism at 52 degrees Celsius, but when radiation and heat were applied simultaneously, synergistic inactivation was observed even at 50 degrees Celsius. Practical implications of these results are discussed

SAXS observation of structural evolution of heated olefin

International Nuclear Information System (INIS)

Sun Minhua; Mou Hongchen; Wang Yuxi; Li Demin; Wang Aiping; Ma Congxiao; Cheng Weidong; Wang Dan; Liu Jia

2007-01-01

Structural evolution of olefin during its heating process was observed with SAXS method at Beijing Synchrotron Radiation Facility. The mean square fluctuation of electron density increased from 468.5 nm -2 at 22 degree C to 2416 nm -2 at 100 degree C, while the electronic gyration radius decreased from 11.61 nm at 22 degree C to 11.16 nm at 100 degree C. Therefore, the olefin softens as a result of the increased thermal motion of the molecules, rather than the shrinking size of fundamental structural units of olefin. (authors)

Effect of degree of subcooling on vapor explosion

International Nuclear Information System (INIS)

Xu Zhihong; Yang Yanhua; Li Tianshu

2010-01-01

In order to investigate the mechanism of the vapor explosion, an observable experiment equipment for low-temperature molten materials to be dropped into water was designed. In the experiment, molten material jet was injected into water to experimentally obtain the visualized information. This experiment results show that the degree of subcooling restrains the explosion. In order to validate the result by other aspects, the breakup experiment was conducted. Results show that the degree of water subcooling is important to melt breakup. High temperature of water is easy to increase the vapor generation during molten material falling, which decrease the drag and accelerated the molten material falling. At the same time, more vapor appear around the molten metal decrease the heat transfer amount between water and molten materials. The two experimental results coincide. (authors)

Demonstration testing and evaluation of in situ soil heating. Revision 1, Demonstration system design

International Nuclear Information System (INIS)

Dev, H.

1994-01-01

Over the last nine years IIT Research Institute (IITRI) has been developing and testing the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. The vaporized contaminants, water vapor and air are recovered from the heated zone by means of a vacuum manifold system which collects gases from below surface as well as from the soil surface. A vapor barrier is used to prevent fugitive emissions of the contaminants and to control air infiltration to minimize dilution of the contaminant gases and vapors. The recovered gases and vapors are conveyed to an on site vapor treatment system for the clean up of the vent gases. Electrical energy is applied to the soil by forming an array of electrodes in the soil which are electrically interconnected and supplied with power. The electrodes are placed in drilled bore holes which are made through the contaminated zone. There are two versions of the in situ heating and soil treatment process: the f irst version is called the In Situ Radio Frequency (RF) Soil Decontamination Process and the second version is called the In Situ Electromagnetic (EM) Soil Decontamination Process. The first version, the RF Process is capable of heating the soil in a temperature range of 100 degrees to 400 degrees C. The soil temperature in the second version, the EM Process, is limited to the boiling point of water under native conditions. Thus the soil will be heated to a temperature of about 85 degrees to 95 degrees C. In this project IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site due to the fact that most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85 degrees to 95 degrees C

Demonstration testing and evaluation of in situ soil heating. Revision 1, Demonstration system design

Energy Technology Data Exchange (ETDEWEB)

Dev, H.

1994-08-16

Over the last nine years IIT Research Institute (IITRI) has been developing and testing the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. The vaporized contaminants, water vapor and air are recovered from the heated zone by means of a vacuum manifold system which collects gases from below surface as well as from the soil surface. A vapor barrier is used to prevent fugitive emissions of the contaminants and to control air infiltration to minimize dilution of the contaminant gases and vapors. The recovered gases and vapors are conveyed to an on site vapor treatment system for the clean up of the vent gases. Electrical energy is applied to the soil by forming an array of electrodes in the soil which are electrically interconnected and supplied with power. The electrodes are placed in drilled bore holes which are made through the contaminated zone. There are two versions of the in situ heating and soil treatment process: the f irst version is called the In Situ Radio Frequency (RF) Soil Decontamination Process and the second version is called the In Situ Electromagnetic (EM) Soil Decontamination Process. The first version, the RF Process is capable of heating the soil in a temperature range of 100{degrees} to 400{degrees}C. The soil temperature in the second version, the EM Process, is limited to the boiling point of water under native conditions. Thus the soil will be heated to a temperature of about 85{degrees} to 95{degrees}C. In this project IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site due to the fact that most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85{degrees} to 95{degrees}C.

Studies on boiling heat transfer on a hemispherical downward heating surface supposing IVR-AM

International Nuclear Information System (INIS)

Yoshida, Kenji; Matsumoto, Hiroyuki; Matsumoto, Tadayoshi; Kataoka, Isao

2006-01-01

The scale-down experiments supposing the IVR-AM were made on the pool boiling heat transfer from hemispherical downward facing heating surface. The boiling phenomena were realized by flooding the heated hemispherical vessel into the sub-cooled water or saturated water under the atmospheric pressure. The hemispherical vessel supposing the scale-down pressure vessel was made of SUS304 stainless steel. Molten lead, which was preheated up to about 500 degrees Celsius, was put into the vessel and used as the heat source. The vessel was cooled down by flooding into the water to realize the quenching process. The direct observation by using the digital video camera was performed and made clear the special characteristics of boiling phenomena such as the film boiling, the transition boiling and the nucleate boiling taking place in order during the cooling process. The measurement for the wall superheat and heat flux by using thermocouples was also carried out to make clear the boiling heat transfer characteristics during the cooling process. Fifteen thermocouples are inserted in the wall of the hemispherical bowl to measure the temperature distributions and heat flux in the hemispherical bowl. (author)

Linking potential heat source and sink to urban heat island: Heterogeneous effects of landscape pattern on land surface temperature.

Science.gov (United States)

Li, Weifeng; Cao, Qiwen; Lang, Kun; Wu, Jiansheng

2017-05-15

Rapid urbanization has significantly contributed to the development of urban heat island (UHI). Regulating landscape composition and configuration would help mitigate the UHI in megacities. Taking Shenzhen, China, as a case study area, we defined heat source and heat sink and identified strong and weak sources as well as strong and weak sinks according to the natural and socioeconomic factors influencing land surface temperature (LST). Thus, the potential thermal contributions of heat source and heat sink patches were differentiated. Then, the heterogeneous effects of landscape pattern on LST were examined by using semiparametric geographically weighted regression (SGWR) models. The results showed that landscape composition has more significant effects on thermal environment than configuration. For a strong source, the percentage of patches has a positive impact on LST. Additionally, when mosaicked with some heat sink, even a small improvement in the degree of dispersion of a strong source helps to alleviate UHI. For a weak source, the percentage and density of patches have positive impacts on LST. For a strong sink, the percentage, density, and degree of aggregation of patches have negative impacts on LST. The effects of edge density and patch shape complexity vary spatially with the fragmentation of a strong sink. Similarly, the impacts of a weak sink are mainly exerted via the characteristics of percent, density, and shape complexity of patches. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluations of different domestic hot water preparing methods with ultra-low-temperature district heating

DEFF Research Database (Denmark)

Yang, Xiaochen; Li, Hongwei; Svendsen, Svend

2016-01-01

of Legionella in the DHW (domestic hot water) and assure the comfortable temperature, all substations were installed with supplementary heating devices. Detailed measurements were taken in the substations, including the electricity demand of the supplementary heating devices. To compare the energy and economic......This study investigated the performances of five different substation configurations in single-family houses supplied with ULTDH (ultra-low-temperature district heating). The temperature at the heat plant is 46 degrees C and around 40 degrees C at the substations. To avoid the proliferation...... performance of the substations, separate models were built based on standard assumptions. The relative heat and electricity delivered for preparing DHW were calculated. The results showed that substations with storage tanks and heat pumps have high relative electricity demand, which leads to higher integrated...

Pregnant women maintain body temperatures within safe limits during moderate-intensity aqua-aerobic classes conducted in pools heated up to 33 degrees Celsius: an observational study.

Science.gov (United States)

Brearley, Amanda L; Sherburn, Margaret; Galea, Mary P; Clarke, Sandy J

2015-10-01

What is the body temperature response of healthy pregnant women exercising at moderate intensity in an aqua-aerobics class where the water temperature is in the range of 28 to 33 degrees Celsius, as typically found in community swimming pools? An observational study. One hundred and nine women in the second and third trimester of pregnancy who were enrolled in a standardised aqua-aerobics class. Tympanic temperature was measured at rest pre-immersion (T1), after 35minutes of moderate-intensity aqua-aerobic exercise (T2), after a further 10minutes of light exercise while still in the water (T3) and finally on departure from the facility (T4). The range of water temperatures in seven indoor community pools was 28.8 to 33.4 degrees Celsius. Body temperature increased by a mean of 0.16 degrees Celsius (SD 0.35, ptemperature response was not related to the water temperature (T2 r = -0.01, p = 0.9; T3 r = -0.02, p=0.9; T4 r=0.03, p=0.8). Analysis of variance demonstrated no difference in body temperature response between participants when grouped in the cooler, medium and warmer water temperatures (T2 F=0.94, p=0.40; T3 F=0.93, p=0.40; T4 F=0.70, p=0.50). Healthy pregnant women maintain body temperatures within safe limits during moderate-intensity aqua-aerobic exercise conducted in pools heated up to 33 degrees Celsius. The study provides evidence to inform guidelines for safe water temperatures for aqua-aerobic exercise during pregnancy. Copyright © 2015 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

Effect of heat curing methods on the temperature history and strength development of slab concrete for nuclear power plant structures in cold climates

International Nuclear Information System (INIS)

Lee, Gun Cheol; Han, Min Cheol; Baek, Dae Hyun; Koh, Kyung Taek

2012-01-01

The objective of this study was to experimentally investigate the effect of heat curing methods on the temperature history and strength development of slab concrete exposed to -10 degrees Celsius. The goal was to determine proper heat curing methods for the protection of nuclear power plant structures against early-age frost damage under adverse (cold) conditions. Two types of methods were studied: heat insulation alone and in combination with a heating cable. For heat curing with heat insulation alone, either sawdust or a double layer bubble sheet (2-BS) was applied. For curing with a combination of heat insulation and a heating cable, an embedded heating cable was used with either a sawdust cover, a 2-BS cover, or a quadruple layer bubble sheet (4-BS) cover. Seven different slab specimens with dimensions of 1200, 600, 200 mm and a design strength of 27 MPa were fabricated and cured at -10 degrees Celsius for 7 d. The application of sawdust and 2-BS allowed the concrete temperature to fall below 0 degrees Celsius within 40 h after exposure to -10 degrees Celsius, and then, the temperature dropped to -10 degrees Celsius and remained there for 7 d owing to insufficient thermal resistance. However, the combination of a heating cable plus sawdust or 2-BS maintained the concrete temperature around 5 degrees Celsius for 7 d. Moreover, the combination of the heating cable and 4-BS maintained the concrete temperature around 10 degrees Celsius for 7 d. This was due to the continuous heat supply from the heating cable and the prevention of heat loss by the 4-BS. For maturity development, which is an index of early-age frost damage, the application of heat insulation materials alone did not allow the concrete to meet the minimum maturity required to protect against early-age frost damage after 7 d, owing to poor thermal resistance. However, the combination of the heating cable and the heat insulating materials allowed the concrete to attain the minimum maturity level after

Heat transfer measurements of the 1983 kilauea lava flow.

Science.gov (United States)

Hardee, H C

1983-10-07

Convective heat flow measurements of a basaltic lava flow were made during the 1983 eruption of Kilauea volcano in Hawaii. Eight field measurements of induced natural convection were made, giving heat flux values that ranged from 1.78 to 8.09 kilowatts per square meter at lava temperatures of 1088 and 1128 degrees Celsius, respectively. These field measurements of convective heat flux at subliquidus temperatures agree with previous laboratory measurements in furnace-melted samples of molten lava, and are useful for predicting heat transfer in magma bodies and for estimating heat extraction rates for magma energy.

Utes for space heating and cooling in North Africa

International Nuclear Information System (INIS)

Nordell, B.; Grein, M. a.

2006-01-01

The North Africa climate is dry and warm with annual mean temperature from 15 degree centigrade to 25 degree centigrade, with a temperature difference of 20 degree centigrade between the coldest and warmest month. Heating is needed during the short winter and there is a large cooling demand during the long summer. Since the undisturbed ground temperature is equal to the annual mean air temperature, the ground is warmer than the air during the winter and colder than air during summer. This is what is required for the direct use of the ground for heating and cooling. In such systems, ground coupled heating and cooling systems, and also in storage systems, Underground Thermal Energy Storage (UTES), some kind of underground duct (PIPE) system is used to inject or extract heat from the ground. Thermal energy is then stored and recovered by heating and cooling of the ground, while the ducts are the heat exchangers with the system. The duct system could be placed horizontally or vertically (e.g. in boreholes) in the ground. In many cases heat pumps or cooling machines are included in the systems but in favourable cases, such as in the North African climate, the ground can be used directly for heating and cooling. then, only a circulation pump is used to pump water through the underground duct system with high efficiencies. Such systems can also be used for thermal energy storage, during shorter periods (diurnal) or even between the seasons. In September 2005 Sebha University and Luleu University of Technology started a Libyan Swedish collaboration to develop and implement these systems for the North African climate. Sweden has considerable experience in ground coupled systems, theoretically and practically, and there are presently more than 300.000 systems in operation in Sweden, mainly for heating. Most of these are small-scale heating systems for singe-family houses but during the last decade several hundred large-scale systems have been built for heating and cooling of

Secular trends in monthly heating and cooling demands in Croatia

Science.gov (United States)

Cvitan, Lidija; Sokol Jurković, Renata

2016-08-01

This paper analyzes long-term heating and cooling trends for five locations in Croatia from 1901 to 2008 to assist in the revision of Croatia's heating and cooling energy policy. Trends in monthly heating degree-days (HDD) and cooling degree-days (CDD) were determined for three related temperature threshold values each and analyzed to provide insight into the influence of desired thermal comfort on the extent of changes in energy consumption. Monthly trends in the corresponding number of heating days (HD) and cooling days (CD) were also analyzed. A basic investigation of HDD, HD, CDD, and CD trends proved to be essential to the development of a complete description of important climate-related conditions that impact energy demands associated with heating and cooling. In a few cases, the dependence of the trends on the implemented temperature thresholds was rather pronounced and was reflected in great spatial and temporal variations in monthly trends. The statistical significance of the detected monthly trends illustrated a diverse range of possible impacts of climate changes on heating and cooling energy consumption both across and within three main climate regions in Croatia (continental, mountainous, and maritime). It is confirmed that the applied monthly scale for analyses is suitable for assessing heating and cooling practices.

On board short-time high temperature heat treatment of ballast water: a field trial under operational conditions.

Science.gov (United States)

Quilez-Badia, Gemma; McCollin, Tracy; Josefsen, Kjell D; Vourdachas, Anthony; Gill, Margaret E; Mesbahi, Ehsan; Frid, Chris L J

2008-01-01

A ballast water short-time high temperature heat treatment technique was applied on board a car-carrier during a voyage from Egypt to Belgium. Ballast water from three tanks was subjected for a few seconds to temperatures ranging from 55 degrees C to 80 degrees C. The water was heated using the vessel's heat exchanger steam and a second heat exchanger was used to pre-heat and cool down the water. The treatment was effective at causing mortality of bacteria, phytoplankton and zooplankton. The International Maritime Organization (IMO) standard was not agreed before this study was carried out, but comparing our results gives a broad indication that the IMO standard would have been met in some of the tests for the zooplankton, in all the tests for the phytoplankton; and probably on most occasions for the bacteria. Passing the water through the pump increased the kill rate but increasing the temperature above 55 degrees C did not improve the heat treatment's efficacy.

Irradiation in combination of heat treatment of mango puree

International Nuclear Information System (INIS)

Noomhorm, A.; Apintanapong, M.

1996-01-01

The effect of irradiation with heat combination treatment on the shelf life and quality of mango puree was studied. Thermal inactivation of polyphenol oxidase enzyme at 80 degree C and 15 min. was used as a measure of adequacy of pre-heat treatment. Irradiation of mango puree after heat treatment at dosage of 0, 2, 4, 6 and 8 kGy showed no change in mc, pH, acidity, and TSS but during storage, growth of microorganisms brought changes in these values. Irradiation in combination with low temperature (5 degree C) reduced discoloration and darkening rate during storage. Irradiation dose from 0 to 8 kGy resulted in log linear reductions in microorganism levels but at 6 and 8 kGy, there was no growth of microorganisms. Products irradiated at 8 kGy showed no microorganism growth at both temperatures

Non-Uniform Heat Transfer in Thermal Regenerators

DEFF Research Database (Denmark)

Jensen, Jesper Buch

, a numerical model, which simulates a single-blow operation in a parallel-plate regenerator, was developed and used to model the heat transfer under various conditions. In addition to the modeling of the heat transfer, a series of experiments on passive regenerators with non-uniform, but precisely controlled....... Additionally, the experiments gave real comparative results, whereas the model to a certain degree more served to provide insight to the heat transfer processes taking place inside the regenera- tors, something that would be - if not impossible - then highly impractical to do experimentally. It has been found......This thesis presents investigations on the heat transfer in complex heat ex- changers in general and in regenerative heat exchangers (regenerators) in par- ticular. The motivation for this work is a result of inconsistencies obeserved in the results from a series of experiments on active magnetic...

Degree-degree correlations in directed networks with heavy-tailed degrees

NARCIS (Netherlands)

van der Hoorn, W.L.F.; Litvak, Nelli

2013-01-01

In network theory, Pearson's correlation coefficients are most commonly used to measure the degree assortativity of a network. We investigate the behavior of these coefficients in the setting of directed networks with heavy-tailed degree sequences. We prove that for graphs where the in- and

Tritium removal by CO2 laser heating

International Nuclear Information System (INIS)

Skinner, C.H.; Kugel, H.; Mueller, D.

1997-01-01

Efficient techniques for rapid tritium removal will be necessary for ITER to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO 2 or Nd:Yag laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel. The authors have modeled the heat propagation into a surface layer and find that a multi-kW/cm 2 flux with an exposure time of order 10 ms is suitable to heat a 50 micron co-deposited layer to 1,000--2,000 degrees. Improved wall conditioning may be a significant side benefit. They identify remaining issues that need to be addressed experimentally

Tritium removal by CO2 laser heating

International Nuclear Information System (INIS)

Skinner, C.H.; Kugel, H.; Mueller, D.

1997-10-01

Efficient techniques for rapid tritium removal will be necessary for ITER (International Thermonuclear Experimental Reactor) to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO 2 or Nd:YAG laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel. The authors have modeled the heat propagation into a surface layer and find that a multi-kW/cm 2 flux with an exposure time of order 10 msec is suitable to heat a 50 micron co-deposited layer to 1,000--2,000 degrees. Improved wall conditioning may be a significant side benefit. They identify remaining issues that need to be addressed experimentally

Susceptibility of Plodia interpunctella (Lepidoptera: Pyralidae) developmental stages to high temperatures used during structural heat treatments.

Science.gov (United States)

Mahroof, R; Subramanyam, B

2006-12-01

Heating the ambient air of a whole, or a portion of a food-processing facility to 50 to 60 degrees C and maintaining these elevated temperatures for 24 to 36 h, is an old technology, referred to as heat treatment. There is renewed interest in adopting heat treatments around the world as a viable insect control alternative to fumigation with methyl bromide. There is limited published information on responses of the Indian meal moth, Plodia interpunctella (Hübner), exposed to elevated temperatures typically used during heat treatments. Time-mortality relationships were determined for eggs, fifth-instars (wandering-phase larvae), pupae, and adults of P. interpunctella exposed to five constant temperatures between 44 and 52 degrees C. Mortality of each stage increased with increasing temperature and exposure time. In general, fifth-instars were the most heat-tolerant stage at all temperatures tested. Exposure for a minimum of 34 min at 50 degrees C was required to kill 99% of the fifth-instars. It is proposed that heat treatments aimed at controlling fifth-instars should be able to control all other stages of P. interpunctella.

Degree-degree dependencies in directed networks with heavy-tailed degrees

NARCIS (Netherlands)

van der Hoorn, W.L.F.; Litvak, Nelly

2015-01-01

In network theory, Pearson’s correlation coefficients are most commonly used to measure the degree assortativity of a network. We investigate the behavior of these coefficients in the setting of directed networks with heavy-tailed degree sequences. We prove that for graphs where the in- and

Estimation of bulk transfer coefficient for latent heat flux (Ce)

Digital Repository Service at National Institute of Oceanography (India)

Sadhuram, Y.

The bulk transfer coefficient for latent heat flux (Ce) has been estimated over the Arabian Sea from the moisture budget during the pre-monsoon season of 1988. The computations have been made over two regions (A: 0-8 degrees N: 60-68 degrees E: B: 0...

Heat flow in the Izu-Ogasawara (Bonin)-Mariana arc

Energy Technology Data Exchange (ETDEWEB)

Yamazaki, T. (Geological Survey of Japan, Tsukuba (Japan))

1992-04-27

New heat flow data of 218 points obtained from 1984 to 1989 in the Izu-Ogasawara(Bonin)-Mariana Arc and their interpretation are presented. The purpose of the measurements is to evaluate the potential of hydrothermal activity and to increase an understanding of the tectonics in this region. The Sumisu Rift shows high and variable heat flow values, which suggests the existence of hydrothermal circulation. The Nishinoshima Trough is bounded on the west by a steep fault scarp, and heat flow is higher in the trough than to the west of the scarp. This contrast was considered to reflect difference in crustal thickness caused by old rifting. Local high heat flow associated with an intrusive body is found in the trough. The Mariana Trough north of 22{degree}N, which is currently in a rifting stage, shows thermal asymmetry. In the Mariana Trough south of 22{degree}N, which has developed to a spreading stage, anomalous temperature profiles suggesting hydrothermal circulation are found near the spreading centers. 44 refs., 11 figs., 1 tab.

Heat disposal in water environment

International Nuclear Information System (INIS)

Harleman, D.R.F.

1975-01-01

The need for continuing development of techniques for predicting temperature distributions due to waste heat discharges into lakes, rivers, estuaries, and the oceans is presented. Diffusion of buoyant jets is examined, including heated surface jets and multiple jets issuing from a submerged multiport diffuser. In the near-field analysis of surface jets the important problems are related to the lateral spreading caused by buoyancy. Comparison of theoretical predictions with laboratory and field observations is given. The mechanics of multiport diffusers for heated discharges in shallow receiving waters are explained in contrast to sewage diffusers. The important problem is the degree to which stratification can be maintained in order to minimize local reintrainment and reduction of dilution capacity. Criteria for stable and unstable flow regimes are provided. A mathematical model for temperature distribution, with or without waste heat addition, in unsteady flows under time-varying meteorological conditions is given. (auth)

Effects of Ohmic Heating on Microbial Counts and Denaturatiuon of Proteins in Milk

OpenAIRE

SUN, Huixian; KAWAMURA, Shuso; HIMOTO, Jun-ichi; ITOH, Kazuhiko; WADA, Tatsuhiko; KIMURA, Toshinori

2008-01-01

The aim of this study was to compare the inactivation effects of ohmic heating (internal heating by electric current) and conventional heating (external heating by hot water) on viable aerobes and Streptococcus thermophilus 2646 in milk under identical temperature history conditions. The effects of the two treatments on quality of milk were also compared by assessing degrees of protein denaturation in raw and sterilized milk (raw milk being sterilized by ohmic heating or conventional heating)...

Effect of recent popularity on heat-conduction based recommendation models

Science.gov (United States)

Li, Wen-Jun; Dong, Qiang; Shi, Yang-Bo; Fu, Yan; He, Jia-Lin

2017-05-01

Accuracy and diversity are two important measures in evaluating the performance of recommender systems. It has been demonstrated that the recommendation model inspired by the heat conduction process has high diversity yet low accuracy. Many variants have been introduced to improve the accuracy while keeping high diversity, most of which regard the current node-degree of an item as its popularity. However in this way, a few outdated items of large degree may be recommended to an enormous number of users. In this paper, we take the recent popularity (recently increased item degrees) into account in the heat-conduction based methods, and propose accordingly the improved recommendation models. Experimental results on two benchmark data sets show that the accuracy can be largely improved while keeping the high diversity compared with the original models.

Differential regulation by heat stress of novel cytochrome P450 genes from the dinoflagellate symbionts of reef-building corals.

Science.gov (United States)

Rosic, Nedeljka N; Pernice, Mathieu; Dunn, Simon; Dove, Sophie; Hoegh-Guldberg, Ove

2010-05-01

Exposure to heat stress has been recognized as one of the major factors leading to the breakdown of the coral-alga symbiosis and coral bleaching. Here, we describe the presence of three new cytochrome P450 (CYP) genes from the reef-building coral endosymbiont Symbiodinium (type C3) and changes in their expression during exposure to severe and moderate heat stress conditions. Sequence analysis of the CYP C-terminal region and two conserved domains, the "PERF" and "heme-binding" domains, confirmed the separate identities of the CYP genes analyzed. In order to explore the effects of different heat stress scenarios, samples of the scleractinian coral Acropora millepora were exposed to elevated temperatures incrementally over an 18-h period (rapid thermal stress) and over a 120-h period (gradual thermal stress). After 18 h of gradual heating and incubation at 26 degrees C, the Symbiodinium CYP mRNA pool was approximately 30% larger, while a further 6 degrees C increase to a temperature above the average sea temperature (29 degrees C after 72 h) resulted in a 2- to 4-fold increase in CYP expression. Both rapid heat stress and gradual heat stress at 32 degrees C resulted in 50% to 90% decreases in CYP gene transcript abundance. Consequently, the initial upregulation of expression of CYP genes at moderately elevated temperatures (26 degrees C and 29 degrees C) was followed by a decrease in expression under the greater thermal stress conditions at 32 degrees C. These findings indicate that in the coral-alga symbiosis under heat stress conditions there is production of chemical stressors and/or transcriptional factors that regulate the expression of genes, such as the genes encoding cytochrome P450 monooxygenases, that are involved in the first line of an organism's chemical defense.

Laboratory Performance Testing of Warm-Mix Asphalt Technologies for Airfield Pavements

Science.gov (United States)

2013-12-01

Fahrenheit (F-32)/1.8 degrees Celsius feet 0.3048 meters foot-pounds force 1.355818 joules gallons (US liquid) 3.785412 E-03 cubic meters inches 0.0254...557 20 5 498 18.7 451 19.7 415 16.6 455 18 1 306 19.4 280 20.7 264 16.8 283 19 0.5 230 19.1 210 21.7 192 18.3 211 20 0.1 175 16.2 157 20.4 137

Development of a new distillation unit combined with compressed heat pump (heat integrated distillation column (HIDiC)) (eco-energy city project)

Energy Technology Data Exchange (ETDEWEB)

Nakanishi, Toshinari; Aso, Kazumasa [Kimura Chemical Plants Co., Ltd., Amagasaki City, Hyogo (Japan); Takamatsu, Takeichiro [Research Inst. of Industrial Technology, Suita-City, Osaka (Japan); Nakaiwa, Masaru [National Inst. of Materials and Chemical Research, Tsukuba, Ibaraki (Japan); Noda, Hideo; Kuratani, Nobuyuki [Kansai Chemical Engineearing Co., Ltd., Amagasaki-city, Hyogo (Japan); Yoshida, Kazufumi [Maruzen Petrochemical Co., Ltd., 25-10, Tokyo (Japan)

1999-07-01

To reduce the irreversible loss the Heat Integrated Distillation Column (HIDiC) is proposed by application of heat-pump technology. (Distillation column, which is an energy consuming separation unit, has been widely used in oil refinery and the other chemical-related plants. The reason why it is a major energy consumer is that a large amount of irreversible loss occurs in heat transfer within the process.) In this paper, current results on the study of HIDiC in both simulations and experiments are shown. HIDiC must be operated at a higher pressure in the rectifying section so as to make its temperature higher than that of the stripping section which stands parallel with the rectifying section. That makes heat transfer from the rectifying section to the stripping section. Because of vaporization in the stripping section and condensation in the rectifying section, the energy for the reboiler can be saved. The degree of energy saving can be expected to be much more than 30%, although the exact value depends on the characteristics of mixture to be separated. (The degree of energy saving is higher than the above, if the exhaust vapor from the HIDiC is used to heat the feed or the other processes.) To save energy by the HIDiC, high separation performances and heat transfer capabilities are required. It has been found out that the HIDiC, whose shape is like vertical shell and tube heat exchanger was enough to be practical use of the HIDiC from the static design principle points of view. (orig.)

Effect of heating strategies on whey protein denaturation--Revisited by liquid chromatography quadrupole time-of-flight mass spectrometry.

Science.gov (United States)

Akkerman, M; Rauh, V M; Christensen, M; Johansen, L B; Hammershøj, M; Larsen, L B

2016-01-01

Previous standards in the area of effect of heat treatment processes on milk protein denaturation were based primarily on laboratory-scale analysis and determination of denaturation degrees by, for example, electrophoresis. In this study, whey protein denaturation was revisited by pilot-scale heating strategies and liquid chromatography quadrupole time-of-flight mass spectrometer (LC/MC Q-TOF) analysis. Skim milk was heat treated by the use of 3 heating strategies, namely plate heat exchanger (PHE), tubular heat exchanger (THE), and direct steam injection (DSI), under various heating temperatures (T) and holding times. The effect of heating strategy on the degree of denaturation of β-lactoglobulin and α-lactalbumin was determined using LC/MC Q-TOF of pH 4.5-soluble whey proteins. Furthermore, effect of heating strategy on the rennet-induced coagulation properties was studied by oscillatory rheometry. In addition, rennet-induced coagulation of heat-treated micellar casein concentrate subjected to PHE was studied. For skim milk, the whey protein denaturation increased significantly as T and holding time increased, regardless of heating method. High denaturation degrees were obtained for T >100°C using PHE and THE, whereas DSI resulted in significantly lower denaturation degrees, compared with PHE and THE. Rennet coagulation properties were impaired by increased T and holding time regardless of heating method, although DSI resulted in less impairment compared with PHE and THE. No significant difference was found between THE and PHE for effect on rennet coagulation time, whereas the curd firming rate was significantly larger for THE compared with PHE. Micellar casein concentrate possessed improved rennet coagulation properties compared with skim milk receiving equal heat treatment. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of pre-heating on the viscosity and microhardness of a resin composite.

LENUS (Irish Health Repository)

Lucey, S

2010-04-01

The effect of pre-heating resin composite on pre-cured viscosity and post-cured surface hardness was evaluated. Groups of uncured specimens were heated to 60 degrees C and compared with control groups (24 degrees C) with respect to viscosity and surface hardness. Mean (SD) viscosities of the pre-heated specimens (n = 15) were in the range of 285 (13)-377 (11) (Pa) compared with 642 (35)-800 (23) (Pa) at ambient temperature. There was a statistically significant difference between the two groups (P < 0.001). Mean (SD) Vickers microhardness (VHN) of the pre-heated group (n = 15) was 68.6 (2.3) for the top surface and 68.7 (1.8) for the bottom surface measured at 24 h post curing (specimen thickness = 1.5 mm). The corresponding values for the room temperature group were 60.6 (1.4) and 59.0 (3.5). There was a statistically significant difference between corresponding measurements taken at the top and bottom for the pre-heated and room temperature groups (P < 0.001). There was no significant difference between top and bottom measurements within each group. Pre-heating resin composite reduces its pre-cured viscosity and enhances its subsequent surface hardness. These effects may translate as easier placement together with an increased degree of polymerization and depth-of-cure.

Effect of water content on specific heat capacity of porcine septum cartilage

Science.gov (United States)

Chae, Yongseok; Lavernia, Enrique J.; Wong, Brian J.

2002-06-01

The effect of water content on specific heat capacity was examined using temperature modulated Differential Scanning Calorimetry (TMDSC). This research was motivated in part by the development laser cartilage reshaping operations, which use photothermal heating to accelerate stress relaxation and shape change. Deposition of thermal energy leads to mechanical stress relaxation and redistribution of cartilage internal stresses, which may lead to a permanent shape change. The specific heat of cartilage specimens (dia: 3 mm and thickness 1-2 mm) was measured using a heating rate of 2 degree(s)C/min for conventional DSC and 2 degree(s)C/min with an amplitude 0.38-0.45 degree(s)C and a period 60-100 sec for TMDSC. The amount of water in cartilaginous tissue was determined using thermogravimetry analysis (TGA) under ambient conditions. In order to correlate changes in heat flow with alterations in cartilage mechanical behavior, dynamic mechanical temperature analysis (DMTA) was used to estimate the specific transition temperatures where stress relaxation occurs. With decreasing water content, we identified a phase transition that shifted to a higher temperature after 35-45% water content was measured. The phase transition energy increased from 0.12 J/g to 1.68 J/g after a 45% weight loss. This study is a preliminary investigation focused on understanding the mechanism of the stress relaxation of cartilage during heating. The energy requirement of such a transition estimated using TMDSC and temperature range, where cartilage shape changes likely occur, was estimated.

General purpose heat source task group. Final report

International Nuclear Information System (INIS)

1979-01-01

The results of thermal analyses and impact tests on a modified design of a 238 Pu-fueled general purpose heat source (GPHS) for spacecraft power supplies are presented. This work was performed to establish the safety of a heat source with pyrolytic graphite insulator shells located either inside or outside the graphite impact shell. This safety is dependent on the degree of aerodynamic heating of the heat source during reentry and on the ability of the heat source capsule to withstand impact after reentry. Analysis of wind tunnel and impact test data result in a recommended GPHS design which should meet all temperature and safety requirements. Further wind tunnel tests, drop tests, and impact tests are recommended to verify the safety of this design

Combined effect of gamma radiation and heating on the destruction of Listeria monocytogenes and Salmonella typhimurium in cook-chill roast beef and gravy.

Science.gov (United States)

Grant, I R; Patterson, M F

1995-10-01

The effect of heating alone (60, 65 or 70 degrees C), heating after irradiation (0.8 kGy) and heating after irradiation and storage for 14 days at 2-3 degrees C on the destruction of Listeria monocytogenes and Salmonella typhimurium in artifically inoculated minced cook-chill roast beef and gravy was investigated. Inoculated minced roast beef samples (5 g) were heated in Stomacher bags completely immersed in a water bath at each of the test temperatures. Survivors were enumerated and D and z values were determined for each of the pathogens. Observed thermal D values for two strains of L. monocytogenes at 60, 65 and 70 degrees C in the absence of pre-irradiation were 90.0-97.5 s, 34.0-53.0 s and 22.4-28.0 s, respectively, whereas thermal D values after pre-irradiation were 44.0-46.4 s, 15.3-16.8 s and 5.5-7.8 s at 60, 65 and 70 degrees C, respectively. This reduction in D values provides evidence for radiation-induced heat-sensitisation in L. monocytogenes. There was some evidence of heat-sensitisation of S. typhimurium at 60 degrees C, but not at either 65 or 70 degrees C. The z value also decreased as a consequence of pre-irradiation to a dose of 0.8 kGy (11.0-12.7 degrees C). The radiation-induced heat-sensitivity in L. monocytogenes was found to persist for up to 2 weeks storage at 2-3 degrees C prior to heating. As cook-chill products are intended to be reheated prior to consumption the results of the present study suggest that any L. monocytogenes present in a cook-chill product would be more easily killed during reheating if it were to be treated with a low dose of gamma radiation during manufacture.

Experimental investigation of convection heat transfer of CO2 at supercritical pressures in a vertical circular tube at high Re

International Nuclear Information System (INIS)

Li Zhihui; Jiang Peixue

2008-01-01

Convection heat transfer during the upward flow of CO 2 at supercritical pressures in a vertical circular tube (d in = 2 mm) at high Reynolds numbers was investigated experimentally, and the effects of heat fluxes, mass fluxes, inlet temperatures, pressures, buoyancy and thermal acceleration on the convection heat transfer was analyzed. The results show that the tube wall temperature occurs abnormally distribution for high heat-fluxes with upward flow. The degree of deteriorated heat transfer increases with increasing heat flux. Increasing of the mass flux delays the occurrence of the deterioration of heat transfer and weakens the deterioration of heat transfer down-stream section. The inlet temperature strongly influences the heat transfer. The deterioration degree of heat transfer decreases with increasing pressure. (authors)

Recent results on the neutron irradiation of ITER candidate copper alloys irradiated in DR-3 at 250{degrees}C to 0.3 dpa

Energy Technology Data Exchange (ETDEWEB)

Edwards, D.J. [Pacific Northwest National Lab., Richland, WA (United States); Singh, B.N.; Toft, P.; Eldrup, M.

1997-04-01

Tensile specimens of CuCrZr and CuNiBe alloys were given various heat treatments corresponding to solution anneal, prime-ageing and bonding thermal treatment with additional specimens re-aged and given a reactor bakeout treatment at 350{degrees}C for 100 h. CuAl-25 was also heat treated to simulate the effects of a bonding thermal cycle on the material. A number of heat treated specimens were neutron irradiated at 250{degrees}C to a dose level of {approximately}0.3 dpa in the DR-3 reactor as Riso. The main effect of the bonding thermal cycle heat treatment was a slight decrease in strength of CuCrZr and CuNiBe alloys. The strength of CuAl-25, on the other hand, remained almost unaltered. The post irradiation tests at 250{degrees}C showed a severe loss of ductility in the case of the CuNiBe alloy. The irradiated CuAl-25 and CuCrZr specimens exhibited a reasonable amount of uniform elongation, with CuCrZr possessing a lower strength.

The heat and moisture budgets of the atmosphere over central equatorial Indian Ocean during summer monsoon

Digital Repository Service at National Institute of Oceanography (India)

Sadhuram, Y.; Gopalakrishna, V.V.; RameshBabu, V.; Sastry, J.S.

The heat and moisture budgets of the atmosphere (surface to 100 mb) over the central equatorial Indian Ocean (2 degrees N to 2 degrees S; 76 degrees E to 80 degrees E) have been investigated utilising the surface and upper air data collected...

The urban heat island and its impact on heat waves and human health in Shanghai.

Science.gov (United States)

Tan, Jianguo; Zheng, Youfei; Tang, Xu; Guo, Changyi; Li, Liping; Song, Guixiang; Zhen, Xinrong; Yuan, Dong; Kalkstein, Adam J; Li, Furong

2010-01-01

With global warming forecast to continue into the foreseeable future, heat waves are very likely to increase in both frequency and intensity. In urban regions, these future heat waves will be exacerbated by the urban heat island effect, and will have the potential to negatively influence the health and welfare of urban residents. In order to investigate the health effects of the urban heat island (UHI) in Shanghai, China, 30 years of meteorological records (1975-2004) were examined for 11 first- and second-order weather stations in and around Shanghai. Additionally, automatic weather observation data recorded in recent years as well as daily all-cause summer mortality counts in 11 urban, suburban, and exurban regions (1998-2004) in Shanghai have been used. The results show that different sites (city center or surroundings) have experienced different degrees of warming as a result of increasing urbanization. In turn, this has resulted in a more extensive urban heat island effect, causing additional hot days and heat waves in urban regions compared to rural locales. An examination of summer mortality rates in and around Shanghai yields heightened heat-related mortality in urban regions, and we conclude that the UHI is directly responsible, acting to worsen the adverse health effects from exposure to extreme thermal conditions.

Development of the heat sink structure of a beam dump for the proton accelerator

International Nuclear Information System (INIS)

Maeng, W. Y.; Gil, C. S.; Kim, J. H.; Kim, D. H.

2007-01-01

The beam dump is the essential component for the good beam quality and the reliable performance of the proton accelerator. The beam dump for a 20 MeV and 20 mA proton accelerator was designed and manufactured in this study. The high heats deposited, and the large amount of radioactivity produced in beam dump should be reduced by the proper heat sink structure. The heat source by the proton beam of 20 MeV and 20 mA was calculated. The radioactivity assessments of the beam dump were carried out for the economic shielding design with safety. The radioactivity by the protons and secondary neutrons in designed beam dump were calculated in this sturdy. The effective engineering design for the beam dump cooling was performed, considering the mitigation methods of the deposited heats with small angle, the power densities with the stopping ranges in the materials and the heat distributions in the beam dump. The heat sink structure of the beam dump was designed to meet the accelerator characteristics by placing two plates of 30 cm by 60 cm at an angle of 12 degree. The highest temperatures of the graphite, copper, and copper faced by cooling water were designed to be 223 degree, 146 degree, and 85 degree, respectively when the velocity of cooling water was 3 m/s. The heat sink structure was manufactured by the brazing graphite tiles to a copper plate with the filler alloy of Ti-Cu-Ag. The brazing procedure was developed. The tensile stress of the graphite was less than 75% of a maximum tensile stress during the accelerator operation based on the analysis. The safety analyses for the commissioning of the accelerator operation were also performed. The specimens from the brazed parts of beam dump structure were made to identify manufacturing problems. The soundness of the heat sink structure of the beam dump was confirmed by the fatigue tests of the brazed specimens of the graphite-copper tile components with the repetitive heating and cooling. The heat sink structure developed

Information filtering via biased heat conduction

Science.gov (United States)

Liu, Jian-Guo; Zhou, Tao; Guo, Qiang

2011-09-01

The process of heat conduction has recently found application in personalized recommendation [Zhou , Proc. Natl. Acad. Sci. USA PNASA60027-842410.1073/pnas.1000488107107, 4511 (2010)], which is of high diversity but low accuracy. By decreasing the temperatures of small-degree objects, we present an improved algorithm, called biased heat conduction, which could simultaneously enhance the accuracy and diversity. Extensive experimental analyses demonstrate that the accuracy on MovieLens, Netflix, and Delicious datasets could be improved by 43.5%, 55.4% and 19.2%, respectively, compared with the standard heat conduction algorithm and also the diversity is increased or approximately unchanged. Further statistical analyses suggest that the present algorithm could simultaneously identify users' mainstream and special tastes, resulting in better performance than the standard heat conduction algorithm. This work provides a creditable way for highly efficient information filtering.

Tensile properties of vanadium alloys irradiated at 390{degrees}C in EBR-II

Energy Technology Data Exchange (ETDEWEB)

Chung, H.M.; Tsai, H.C.; Nowicki, L.J. [Argonne National Lab., IL (United States)] [and others

1997-08-01

Vanadium alloys were irradiated in Li-bonded stainless steel capsules to {approx}390{degrees}C in the EBR-II X-530 experiment. This report presents results of postirradiation tests of tensile properties of two large-scale (100 and 500 kg) heats of V-4Cr-Ti and laboratory (15-30 kg) heats of boron-doped V-4Cr-4Ti, V-8Cr-6Ti, V-5Ti, and V-3Ti-1Si alloys. Tensile specimens, divided into two groups, were irradiated in two different capsules under nominally similar conditions. The 500-kg heat (No. 832665) and the 100-kg heat (VX-8) of V-4Cr-4Ti irradiated in one of the subcapsules exhibited complete loss of work-hardening capability, which was manifested by very low uniform plastic strain. In contrast, the 100-kg heat of V-4Cr-4Ti irradiated in another subcapsule exhibited good tensile properties (uniform plastic strain 2.8-4.0%). A laboratory heat of V-3Ti-1Si irradiated in the latter subcapsule also exhibited good tensile properties. These results indicate that work-hardening capability at low irradiation temperatures varies significantly from heat to heat and is influenced by nominally small differences in irradiation conditions.

Heat flow, deep formation temperature and thermal structure of the Tarim Basin, northwest China

Science.gov (United States)

Liu, Shaowen; Lei, Xiao; Feng, Changge; Li, Xianglan

2016-04-01

Geothermal regime of a sedimentary basin not only provides constraint on understanding the basin formation and evolution, but also offers fundamental parameters for hydrocarbon resources assessment. As one of three Precambrian blocks in China, the Tarim craton is also a current hydrocarbon exploration target where the largest sedimentary basin (Tarim Basin) develops with great potential. Although considerable advancement of geothermal regime of this basin has been made during the past decades, nearly all the temperature data in previous studies are from the exploration borehole formation testing temperatures. Recently, we have conducted the steady-state temperature logging in the Tarim basin, and measured abundant rock thermal properties, enabling us to re-visit the thermal regime of this area with more confidence. Our results show that the present-day geothermal gradients for the Tarim Basin vary from 23 K/km to 27 K/km, with a mean of 22 K/km; the values of heat flow range from 40 mW/m2 to 49 mW/m2, with a mean of 43 mW/m2. These new data confirmed that the Tarim Basin has relatively low heat flow and shares similar geothermal regime with other Precambrian cratons in the world. In addition, the new temperatures from the steady-state logs are larger than the bottom hole temperatures (BHT) as 22 degree Celsius, indicating the thermal non-equilibrium for the BHTs used in previous studies. Spatial distribution of the estimated formation temperatures-at-depth of 1~5km within the basin is similar and mainly controlled by crystalline basement pattern. Generally, the temperatures at the depth of 1km range from 29 to 41 degree Celsius, with a mean of 35 degree Celsius; while the temperatures at 3km vary from 63 to 100 degree Celsius, and the mean is 82 degree Celsius; at 5km below the surface, the temperatures fall into a range between 90 and 160 degree Celsius, with a mean of 129 degree Celsius. We further proposed the long-term low geothermal background and large burial

Kinetic Hydration Heat Modeling for High-Performance Concrete Containing Limestone Powder

Directory of Open Access Journals (Sweden)

Xiao-Yong Wang

2017-01-01

Full Text Available Limestone powder is increasingly used in producing high-performance concrete in the modern concrete industry. Limestone powder blended concrete has many advantages, such as increasing the early-age strength, reducing the setting time, improving the workability, and reducing the heat of hydration. This study presents a kinetic model for modeling the hydration heat of limestone blended concrete. First, an improved hydration model is proposed which considers the dilution effect and nucleation effect due to limestone powder addition. A degree of hydration is calculated using this improved hydration model. Second, hydration heat is calculated using the degree of hydration. The effects of water to binder ratio and limestone replacement ratio on hydration heat are clarified. Third, the temperature history and temperature distribution of hardening limestone blended concrete are calculated by combining hydration model with finite element method. The analysis results generally agree with experimental results of high-performance concrete with various mixing proportions.

Thermodynamic Heat Water by The Condenser of Refrigerator

International Nuclear Information System (INIS)

Ben Slama, Romdhane

2009-01-01

The present innovation relates to the coupling of a refrigerator to a cumulus to heat water and this, thanks to the heat yielded to the level of the condenser of the refrigerating system even. The heating of water is carried out thus without energy over consumption. The quantity of heat transferred by the water-cooled condenser is sufficient to raise the temperature of this latter with 60 degree at the end of five hours. This can satisfy completely or partially the requirements out of hot water of a family which can distribute its requirements out of hot water all along the day and the week. The quantity of heat recovered by water to heat rises with four multiples the power consumption by the compressor. The system thus makes it possible to save energy and to safeguard the environment

Hand immersion in cold water alleviating physiological strain and increasing tolerance to uncompensable heat stress.

Science.gov (United States)

Khomenok, Gennadi A; Hadid, Amir; Preiss-Bloom, Orahn; Yanovich, Ran; Erlich, Tomer; Ron-Tal, Osnat; Peled, Amir; Epstein, Yoram; Moran, Daniel S

2008-09-01

The current study examines the use of hand immersion in cold water to alleviate physiological strain caused by exercising in a hot climate while wearing NBC protective garments. Seventeen heat acclimated subjects wearing a semi-permeable NBC protective garment and a light bulletproof vest were exposed to a 125 min exercise-heat stress (35 degrees C, 50% RH; 5 km/h, 5% incline). The heat stress exposure routine included 5 min rest in the chamber followed by two 50:10 min work-rest cycles. During the control trial (CO), there was no intervention, whilst in the intervention condition the subjects immersed their hands and forearms in a 10 degrees C water bath (HI). The results demonstrated that hand immersion in cold water significantly reduced physiological strain. In the CO exposure during the first and second resting periods, the average rectal temperature (T (re)) practically did not decrease. With hand immersion, the mean (SD) T (re) decreased by 0.45 (0.05 degrees C) and 0.48 degrees C (0.06 degrees C) during the first and second rest periods respectively (P immersion in cold water for 10 min is an effective method for decreasing the physiological strain caused by exercising under heat stress while wearing NBC protective garments. The method is convenient, simple, and allows longer working periods in hot or contaminated areas with shorter resting periods.

An experimental observation of the effect of flow direction for evaporation heat transfer in plate heat exchanger

International Nuclear Information System (INIS)

Lin, Yueh-Hung; Li, Guang-Cheng; Yang, Chien-Yuh

2015-01-01

This study provides an Infrared Thermal Image observation on the evaporation heat transfer of refrigerant R-410A in plate heat exchanger with various flow arrangement and exit superheat conditions. An experimental method was derived for estimating the superheat region area of two-phase refrigerant evaporation in plate heat exchanger. The experimental results show that the superheat region area for parallel flow is much larger than that for counter flow as that estimated by Yang et al. [9]. There is an early superheated region at the central part of the plate heat exchanger for parallel flow arrangement. This effect is not significant for counter flow arrangement. The Yang et al. [9] method under estimated the superheat area approximately 40%–53% at various flow rates and degree of exit superheat. Even though the flow inside a plate heat exchanger is extremely turbulent because of the chevron flow passages, the assumption of uniform temperature distribution in the cross section normal to the bulk flow direction will cause significant uncertainties for estimating the superheat area for refrigerant evaporating in a plate heat exchanger

Sorption phenomena of methanol on heat treated coal; Netsushori wo hodokoshita sekitan no methanol kyuchaku tokusei

Energy Technology Data Exchange (ETDEWEB)

Yasuda, H.; Kaiho, M.; Yamada, O.; Soneda, Y.; Kobayashi, M.; Makino, M. [National Institute for Resources and Environment, Tsukuba (Japan)

1996-10-28

Experiments were carried out to learn methanol sorption characteristics of heat-treated coal. When Taiheiyo coal is heat-treated at 125{degree}C, performed with a first methanol adsorption at 25{degree}C, and then desorption at 25{degree}C, a site with strong interaction with methanol and a site with relatively weak interaction are generated in test samples. A small amount of methanol remains in both sites. Then, when the methanol is desorbed at as low temperature as 70{degree}C, the methanol in the site with strong interaction remains as it has existed therein, but the methanol in the site with relatively weak interaction desorbs partially, hence the adsorption amount in a second adsorption at 25{degree}C increases. However, when desorption is performed at as high temperature as 125{degree}C, the methanol in the site with strong interaction also desorbs, resulting in increased adsorption heat in the second adsorption. The adsorption velocity drops, however. Existence of methanol in a site with strong interaction affects the adsorption velocity, but no effect is given by methanol in a site with weak interaction. 3 refs., 4 figs.

Space heating with ultra-low-temperature district heating - a case study of four single-family houses from the 1980s

DEFF Research Database (Denmark)

Østergaard, Dorte Skaarup; Svendsen, Svend

2017-01-01

. These benefits can be maximized if district heating temperatures are lowered as much as possible. In this paper we report on a project where 18 Danish single-family houses from the 1980s were supplied by ultra-low temperature district heating with a supply temperature as low as 45 degrees C for the main part...... of the year. The houses were heated by the existing hydraulic radiator systems, while domestic hot water was prepared by use of district heating and electric boosting. This paper evaluated the heating system temperatures that were necessary in order to maintain thermal comfort in four of the houses. First...... the four houses were modelled in the building simulation tool IDA ICE. The simulation models included the actual radiator sizes and the models were used to simulate the expected thermal comfort in the houses and resulting district heating return temperatures. Secondly measurements of the actual district...

A comparative analysis of heat waves and associated mortality in St. Louis, Missouri--1980 and 1995.

Science.gov (United States)

Smoyer, K E

1998-08-01

This research investigates heat-related mortality during the 1980 and 1995 heat waves in St. Louis, Missouri. St. Louis has a long history of extreme summer weather, and heat-related mortality is a public health concern. Heat waves are defined as days with apparent temperatures exceeding 40.6 degrees C (105 degrees F). The study uses a multivariate analysis to investigate the relationship between mortality and heat wave intensity, duration, and timing within the summer season. The heat wave of 1980 was more severe and had higher associated mortality than that of 1995. To learn if changing population characteristics, in addition to weather conditions, contributed to this difference, changes in population vulnerability between 1980 and 1995 are evaluated under simulated heat wave conditions. The findings show that St. Louis remains at risk of heat wave mortality. In addition, there is evidence that vulnerability has increased despite increased air-conditioning penetration and public health interventions.

Pre-heated dual-cured resin cements: analysis of the degree of conversion and ultimate tensile strength

Directory of Open Access Journals (Sweden)

Flávio Álvares França

2011-04-01

Full Text Available This study evaluated the degree of conversion (DC and ultimate tensile strength (UTS of dual-cured resin cements heated to 50º C prior to and during polymerization. Disc- and hourglass-shaped specimens of Rely X ARC (RX and Variolink II (VII were obtained using addition silicon molds. The products were manipulated at 25º C or 50º C and were subjected to 3 curing conditions: light-activation through a glass slide or through a pre-cured 2-mm thick resin composite disc, or they were allowed to self-cure (SC. All specimens were dark-stored dry for 15 days. For DC analysis, the resin cements were placed into the mold located on the center of a horizontal diamond on the attenuated total reflectance element in the optical bench of a Fourier Transformed Infrared spectrometer. Infrared spectra (n = 6 were collected between 1680 and 1500 cm-1, and DC was calculated by standard methods using changes in ratios of aliphatic-to-aromatic C=C absorption peaks from uncured and cured states. For UTS test, specimens (n = 10 were tested in tension in a universal testing machine (crosshead speed of 1 mm/min until failure. DC and UTS data were submitted to 2-way ANOVA, followed by Tukey's test (α= 5%. Both products showed higher DC at 50º C than at 25º C in all curing conditions. No significant difference in UTS was noted between most light-activated groups at 25º C and those at 50º C. VII SC groups showed higher UTS at 50º C than at 25º C (p < 0.05. Increased temperature led to higher DC, but its effects on resin cement UTS depended on the curing condition.

Energetic and Exergy Efficiency of a Heat Storage Unit for Building Heating

International Nuclear Information System (INIS)

Hazami, Mejdi; Kooli, Sami; Lazaar, Meriem; Farhat, Abdelhamid; Belghith, Ali

2009-01-01

This paper deals with a numerical and experimental investigation of a daily solar storage system conceived and built in Laboratoire de Maitrise des Technologies de l Energie (LMTE, Borj Cedria). This system consists mainly of the storage unit connected to a solar collector unit. The storage unit consists of a wooden case with dimension of 5 m 3 (5 m x 1m x 1m) filed with fin sand. Inside the wooden case was buried a network of a polypropylene capillary heat exchanger with an aperture area equal to 5 m 2 . The heat collection unit consisted of 5 m 2 of south-facing solar collector mounted at a 37 degree tilt angle. In order to evaluate the system efficiency during the charging period (during the day) and discharging period (during the night) an energy and exergy analyses were applied. Outdoor experiments were also carried out under varied environmental conditions for several consecutive days. Results showed that during the charging period, the average daily rates of thermal energy and exergy stored in the heat storage unit were 400 and 2.6 W, respectively. It was found that the net energy and exergy efficiencies in the charging period were 32 pour cent and 22 pour cent, respectively. During the discharging period, the average daily rates of the thermal energy and exergy recovered from the heat storage unit were 2 kW and 2.5 kW, respectively. The recovered heat from the heat storage unit was used for the air-heating of a tested room (4 m x 3 m x 3 m). The results showed that 30 pour cent of the total heating requirement of the tested room was obtained from the heat storage system during the whole night in cold seasons

Humidification on Ventilated Patients: Heated Humidifications or Heat and Moisture Exchangers?

Science.gov (United States)

Cerpa, F; Cáceres, D; Romero-Dapueto, C; Giugliano-Jaramillo, C; Pérez, R; Budini, H; Hidalgo, V; Gutiérrez, T; Molina, J; Keymer, J

2015-01-01

The normal physiology of conditioning of inspired gases is altered when the patient requires an artificial airway access and an invasive mechanical ventilation (IMV). The endotracheal tube (ETT) removes the natural mechanisms of filtration, humidification and warming of inspired air. Despite the noninvasive ventilation (NIMV) in the upper airways, humidification of inspired gas may not be optimal mainly due to the high flow that is being created by the leakage compensation, among other aspects. Any moisture and heating deficit is compensated by the large airways of the tracheobronchial tree, these are poorly suited for this task, which alters mucociliary function, quality of secretions, and homeostasis gas exchange system. To avoid the occurrence of these events, external devices that provide humidification, heating and filtration have been developed, with different degrees of evidence that support their use.

Heat capacity for systems with excited-state quantum phase transitions

Energy Technology Data Exchange (ETDEWEB)

Cejnar, Pavel; Stránský, Pavel, E-mail: stransky@ipnp.troja.mff.cuni.cz

2017-03-18

Heat capacities of model systems with finite numbers of effective degrees of freedom are evaluated using canonical and microcanonical thermodynamics. Discrepancies between both approaches, which are observed even in the infinite-size limit, are particularly large in systems that exhibit an excited-state quantum phase transition. The corresponding irregularity of the spectrum generates a singularity in the microcanonical heat capacity and affects smoothly the canonical heat capacity. - Highlights: • Thermodynamics of systems with excited-state quantum phase transitions • ESQPT-generated singularities of the microcanonical heat capacity • Non-monotonous dependences of the canonical heat capacity • Discord between canonical and microcanonical pictures in the infinite-size limit.

Characterization of Urban Heat and Exacerbation: Development of a Heat Island Index for California

Directory of Open Access Journals (Sweden)

Haider Taha

2017-08-01

Full Text Available To further evaluate the factors influencing public heat and air-quality health, a characterization of how urban areas affect the thermal environment, particularly in terms of the air temperature, is necessary. To assist public health agencies in ranking urban areas in terms of heat stress and developing mitigation plans or allocating various resources, this study characterized urban heat in California and quantified an urban heat island index (UHII at the census-tract level (~1 km2. Multi-scale atmospheric modeling was carried out and a practical UHII definition was developed. The UHII was diagnosed with different metrics and its spatial patterns were characterized for small, large, urban-climate archipelago, inland, and coastal areas. It was found that within each region, wide ranges of urban heat and UHII exist. At the lower end of the scale (in smaller urban areas, the UHII reaches up to 20 degree-hours per day (DH/day; °C.hr/day, whereas at the higher end (in larger areas, it reaches up to 125 DH/day or greater. The average largest temperature difference (urban heat island within each region ranges from 0.5–1.0 °C in smaller areas to up to 5 °C or more at the higher end, such as in urban-climate archipelagos. Furthermore, urban heat is exacerbated during warmer weather and that, in turn, can worsen the health impacts of heat events presently and in the future, for which it is expected that both the frequency and duration of heat waves will increase.

HEAT INDUCIBLE EXPRESSION OF ANTIFREEZE PROTEIN GENES FROM THE BEETLES Tenebrio molitor AND Microdera punctipennis.

Science.gov (United States)

Li, Jieqiong; Ma, Wenjing; Ma, Ji

2016-01-01

Antifreeze proteins (AFPs) play important roles in protecting poikilothermic organisms from cold damage. The expression of AFP genes (afps) is induced by low temperature. However, it is reported that heat can influence the expression of afps in the desert beetle Microdera punctipennis. To further detect whether heat also induce the expression of afps in other insects, and to determine the expression profiling of insect afps at different temperatures. The expression of antifreeze protein genes in the two beetles, Microdera punctipennis and Tenebrio molitor that have quite different living environment, under different temperatures were studied by using real-time quantitative PCR. Mild low temperatures (5~15 degree C), high temperature (38~47 degree C for M. punctipennis, or 37~42 degree C for T. molitor) and temperature difference (10~30 degree C) all stimulated strongly to the expression of AFP genes (Mpafps) in M. punctipennis which lives in the wild filed in desert. The mRNA level of Mpafps after M. punctipennis were exposed to these temperatures for 1h~5h was at least 30-fold of the control at 25 degree C. For T. molitor which is breeding in door with wheat bran all these temperatures stimulated significantly to the expression of Tmafps, while the extent and degree of the temperature stimulation on Tmafps expression were much lower than on Mpafps. After T. molitor were exposed to 5 degree C and 15 degree C for 1h~5h, the mRNA level of Tmafps was over 6-fold and 45-fold of the control at 25 degree C. High temperature (37~42 degree C) for 1h~3h treatments increased Tmafps mRNA level 4.8-fold of the control. Temperature difference of 10 degree C was effective in stimulating Tmafps expression. The expression of insect antifreeze protein genes both in M. punctipennis and T. molitor was induced by heat, suggesting that this phenomenon may be common in insects; the extent and degree of the influence differ in species that have different living conditions. The heat

Consumer Unit for Low Energy District Heating Net

DEFF Research Database (Denmark)

Paulsen, Otto; Fan, Jianhua; Furbo, Simon

2008-01-01

to reduce heat loss in the network. The consumer’s installation is a unit type with an accumulation tank for smoothing the heat load related to the domestic hot water. The building heat load is delivered by an under-floor heating system. The heavy under-floor heating system is assumed to smooth the room...... heat load on a daily basis, having a flow temperature control based on outdoor climate. The unit is designed for a near constant district heating water flow. The paper describes two concepts. The analyses are based on TRNSYS (Klein et al., 2006) simulation, supplied with laboratory verification......A low energy/ low temperature consumer installation is designed and analyzed. The consumer type is a low energy single family house 145 m2 with annual energy consumption in the range of 7000 kWh, incl. domestic hot water in a 2800 degree day climate. The network is an extreme low temperature system...

Surface temperature and surface heat flux determination of the inverse heat conduction problem for a slab

International Nuclear Information System (INIS)

Kuroyanagi, Toshiyuki

1983-07-01

Based on an idea that surface conditions should be a reflection of interior temperature and interior heat flux variation as inverse as interior conditions has been determined completely by the surface temperature and/on surface heat flux as boundary conditions, a method is presented for determining the surface temperature and the surface heat flux of a solid when the temperature and heat flux at an interior point are a prescribed function of time. The method is developed by the integration of Duhumels' integral which has unknown temperature or unknown heat flux in its integrand. Specific forms of surface condition determination are developed for a sample inverse problem: slab. Ducussing the effect of a degree of avairable informations at an interior point due to damped system and the effect of variation of surface conditions on those formulations, it is shown that those formulations are capable of representing the unknown surface conditions except for small time interval followed by discontinuous change of surface conditions. The small un-resolved time interval is demonstrated by a numerical example. An evaluation method of heat flux at an interior point, which is requested by those formulations, is discussed. (author)

The maximum and minimum values of the heat Q transmitted from metal to boiling water under atmospheric pressure

International Nuclear Information System (INIS)

Nukiyama, S.

1991-01-01

The quantity of heat transmitted from a metal surface to boiling water increases as the temperature difference ΔT is increased, but after the ΔT has reached a certain limit, quantity Q decreases with further increase in ΔT. This turning point is the maximum value of heat transmitted. The existence of this point was actually observed in the experiment. Under atmospheric pressure, ΔT corresponding to the maximum value of heat transfer for water at 100 degrees C falls between 20-40 degrees C, and Q is between 1,080,000 and 1,800,000 kcal/m 2 h (i.e. between 2,000 and 3,000 kg/m 2 h, if expressed in constant evaporation rate at 100 degrees C); this figure is larger than the maximum value of heat transfer as was previously considered. In this paper the minimum value of heat transfer was obtained, and in the Q-ΔT curve for the high temperature region, the burn-out effect is discussed

The Little Heat Engine: Heat Transfer in Solids, Liquids and Gases

Directory of Open Access Journals (Sweden)

Robitaille P.-M.

2007-10-01

Full Text Available In this work, an introductory exposition of the laws of thermodynamics and radiative heat transfer is presented while exploring the concepts of the ideal solid, the lattice, and the vibrational, translational, and rotational degrees of freedom. Analysis of heat transfer in this manner helps scientists to recognize that the laws of thermal radiation are strictly applicable only to the ideal solid. On the Earth, such a solid is best represented by either graphite or soot. Indeed, certain forms of graphite can approach perfect absorption over a relatively large frequency range. Nonetheless, in dealing with heat, solids will eventually sublime or melt. Similarly, liquids will give way to the gas phase. That thermal conductivity eventually decreases in the solid signals an inability to further dissipate heat and the coming breakdown of Planck’s law. Ultimately, this breakdown is reflected in the thermal emission of gases. Interestingly, total gaseous emissivity can de- crease with increasing temperature. Consequently, neither solids, liquids, or gases can maintain the behavior predicted by the laws of thermal emission. Since the laws of thermal emission are, in fact, not universal, the extension of these principles to non-solids constitutes a serious overextension of the work of Kirchhoff, Wien, Stefan and Planck.

Free convective heat loss from cavity-type solar furnace; Solar receiver kara no shizen tairyu ni yoru netsusonshitsu

Energy Technology Data Exchange (ETDEWEB)

Fujii, I; Ito, N [Meiji University, Tokyo (Japan)

1996-10-27

Free convective heat loss from solar heat receivers was studied, using three laboratory model receivers (different in depth L and aperture diameter d) heated by electric heaters. Most of the heat produced by heaters was transmitted to the air inside. The cylindrical vessel walls were fully insulated against heat. Heat loss being supposed to result mainly from transfer by free convection, the experiment results were edited by use of Nusselt number Nu and Rayley number Ra. Relations between Nu(D/d){sup m1} and Ra(L/D){sup m2} were plotted in a chart. Here, D is the receiver inner diameter, and m1 and m2 are constants that can be determined by computation. Tests points were provided approximately lineally, irrespective of D, L, or receiver inclination. Air currents were found to produce one or more swirls inside, thanks to the current visualization technique, when the receiver inclination was not sharper than 120{degree} (except 0{degree}). The number of swirls increased as the inner wall temperature rose. This kind of behavior of air currents directly affects the degree of heat loss. 9 refs., 4 figs.

Engine and radiator: fetal and placental interactions for heat dissipation.

Science.gov (United States)

Schröder, H J; Power, G G

1997-03-01

The 'engine' of fetal metabolism generates heat (3-4 W kg-1 in fetal sheep) which has to be dissipated to the maternal organism. Fetal heat may move through the amniotic/allantoic fluids to the uterine wall (conductive pathway; total conductance, 1.1 W degrees C-1 kg-1) and with the umbilical arterial blood flow (convective pathway) to the placenta. Because resistance to heat flow is larger than zero fetal temperature exceeds maternal temperature by about 0.5 degree C (0.3-1 degree C). Probably 85% of fetal heat is lost to the maternal organism through the placenta, which thus serves as the main 'radiator'. Placental heat conductivity appears to be extremely high and this may lead to impaired heat exchange (guinea-pig placenta). A computer simulation demonstrates that fetal temperature is essentially clamped to maternal temperature, and that fetal thermoregulatory efforts to gain thermal independence would be futile. Indeed, when the late gestational fetus in utero is challenged by cold stress, direct and indirect indicators of (non-shivering) thermogenesis (oxygen consumption, increase of plasma glycerol and free fatty acid levels) change only moderately. In prematurely delivered lambs, however, cold stress provokes summit metabolism and maximum heat production. Only when birth is imitated in utero (by cord clamping, external artificial lung ventilation and cooling) do thermogenic efforts approach levels typical of extra-uterine life. This suggests the presence of inhibitors of thermogenesis of placental origin, e.g. prostaglandins and adenosine. When the synthesis of prostaglandins is blocked by pretreatment with indomethacin, sheep fetuses react to intra-uterine cooling with vigorous thermogenic responses, which can be subdued by infusion of prostaglandin E2 (PGE2). Since the sheep placenta is known to produce sufficient amounts of PGE2, it seems that the placenta controls fetal thermogenic responses to some extent. This transforms the fetus into an ectothermic

Heat transfer coefficient: Medivance Arctic Sun Temperature Management System vs. water immersion.

Science.gov (United States)

English, M J; Hemmerling, T M

2008-07-01

To improve heat transfer, the Medivance Arctic Sun Temperature Management System (Medivance, Inc., Louisville, CO, USA) features an adhesive, water-conditioned, highly conductive hydrogel pad for intimate skin contact. This study measured and compared the heat transfer coefficient (h), i.e. heat transfer efficiency, of this pad (hPAD), in a heated model and in nine volunteers' thighs; and of 10 degrees C water (hWATER) in 33 head-out immersions by 11 volunteers. Volunteer studies had ethical approval and written informed consent. Calibrated heat flux transducers measured heat flux (W m-2). Temperature gradient (DeltaT) was measured between skin and pad or water temperatures. Temperature gradient was changed through the pad's water temperature controller or by skin cooling on immersion. The heat transfer coefficient is the slope of W m-2/DeltaT: its unit is W m-2 degrees C-1. Average with (95% CI) was: model, hPAD = 110.4 (107.8-113.1), R2 = 0.99, n = 45; volunteers, hPAD = 109.8 (95.5-124.1), R2 = 0.83, n = 51; and water immersion, hWATER = 107.1 (98.1-116), R2 = 0.86, n = 94. The heat transfer coefficient for the pad was the same in the model and volunteers, and equivalent to hWATER. Therefore, for the same DeltaT and heat transfer area, the Arctic Sun's heat transfer rate would equal water immersion. This has important implications for body cooling/rewarming rates.

Magnetic field control of 90 Degree-Sign , 180 Degree-Sign , and 360 Degree-Sign domain wall resistance

Energy Technology Data Exchange (ETDEWEB)

Majidi, Roya, E-mail: royamajidi@gmail.com [Department of Physics, Shahid Rajaee Teacher Training University, Lavizan, 16788-15811 Tehran (Iran, Islamic Republic of)

2012-10-01

In the present work, we have compared the resistance of the 90 Degree-Sign , 180 Degree-Sign , and 360 Degree-Sign domain walls in the presence of external magnetic field. The calculations are based on the Boltzmann transport equation within the relaxation time approximation. One-dimensional Neel-type domain walls between two domains whose magnetization differs by angle of 90 Degree-Sign , 180 Degree-Sign , and 360 Degree-Sign are considered. The results indicate that the resistance of the 360 Degree-Sign DW is more considerable than that of the 90 Degree-Sign and 180 Degree-Sign DWs. It is also found that the domain wall resistance can be controlled by applying transverse magnetic field. Increasing the strength of the external magnetic field enhances the domain wall resistance. In providing spintronic devices based on magnetic nanomaterials, considering and controlling the effect of domain wall on resistivity are essential.

Interfacial reaction between SiC and aluminium due to extrusion and heat treatment process

International Nuclear Information System (INIS)

Junaidah Jai; Fauzi Ismail; Samsiah Sulaiman; Patthi Hussain, Azmi Idris; Yoichi Murakoshi

1999-01-01

Chemical interaction between aluminium (Al) and silicon carbide (SiC) produces aluminium carbide (Al 4 C 3 ) which presents potential problems in the production and application of Al/SiC Metal Matrix Composit (MMC). The Al 4 C 3 formed can reduce material properties such as strength in the MMC. This research work investigates the interface reaction in Al 7075/SiC MMC made through hot extrusion process. Mixed Al 7075/SiC MMC powders were pressed at 300 degree C and extruded at 500 degree C, with a reduction ratio of 20:1. The extruded MMC was then heat-treated in air at various temperatures from 560 degree C, 600 degree C, 640 degree C, 700 degree C to 800 degree C in order to observe the interface reaction of the MMC materials. The heat-treated MMCs were then analyzed under the optical microscope, X-ray Diffraction (XRD) Spectroscope and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray (EDAZ) attachment to observe the interface reaction within the MMCs. This investigation confirms there was interface reaction between SiC and aluminium

Screening of cotton (gossypium hirsutum l.) genotypes for heat tolerance

International Nuclear Information System (INIS)

Abro, S.; Khan, M.A.; Sial, M.A.

2015-01-01

Cotton yield is highly affected due to biotic (diseases and pests) and abiotic (heat, dought and salinity) Stresses. Among them, high temperature is the main environmental constraint which adversely reduces cotton yield and quality. High temperature above 36 degree C affects plant growth and development especially during reproductive phase. Present studies were carried out to assess the tolerance of fifty-eight newly evolved cotton genotypes to heat stresses, based on agronomic and physiological characteristics. The genotypes were screened in field conditions under two temperature regimes. The studies were conducted at experimental farm of Nuclear Institute of Agriculture, Tando Jam, Pakistan. The results showed that March sown crop experienced high temperature (i.e. > 44 degree C in May and June), which significantly affected crop growth and productivity. The genotypes were identified as heat-tolerant on the basis of relative cell injury percentage (RCI %), heat susceptibility index (HSI) values, boll retention and seed cotton yield (kg/ha). RCI level in cotton genotypes ranged from 39.0 to 86.0%. Out of 58, seventeen genotypes (viz.NIA-80, NIA-81, NIA-83, NIA-84, NIA-M-30, NIA-M31, NIA-HM-48, NIA-HM-327, NIA-H-32, NIA-HM-2-1, NIA-Bt1, NIA-Bt2, NIA-Perkh, CRIS-342, CRIS-134, NIAB-111 and check variety Sadori indicated high level of heat tolerance at both (heat-stressed and non-stressed) temperature regimes; as shown the lowest relative injury level and relatively heat resistant index (HSI<1) values. Such genotypes could be used as heattolerant genotypes under heat-stressed environments. (author)

Compressed air production with waste heat utilization in industry

Science.gov (United States)

Nolting, E.

1984-06-01

The centralized power-heat coupling (PHC) technique using block heating power stations, is presented. Compressed air production in PHC technique with internal combustion engine drive achieves a high degree of primary energy utilization. Cost savings of 50% are reached compared to conventional production. The simultaneous utilization of compressed air and heat is especially interesting. A speed regulated drive via an internal combustion motor gives a further saving of 10% to 20% compared to intermittent operation. The high fuel utilization efficiency ( 80%) leads to a pay off after two years for operation times of 3000 hr.

Effect of Sodium Carboxymethyl Celluloses on Water-catalyzed Self-degradation of 200-degree C-heated Alkali-Activated Cement

Energy Technology Data Exchange (ETDEWEB)

Sugama T.; Pyatina, T.

2012-05-01

We investigated the usefulness of sodium carboxymethyl celluloses (CMC) in promoting self-degradation of 200°C-heated sodium silicate-activated slag/Class C fly ash cementitious material after contact with water. CMC emitted two major volatile compounds, CO2 and acetic acid, creating a porous structure in cement. CMC also reacted with NaOH from sodium silicate to form three water-insensitive solid reaction products, disodium glycolate salt, sodium glucosidic salt, and sodium bicarbonate. Other water-sensitive solid reaction products, such as sodium polysilicate and sodium carbonate, were derived from hydrolysates of sodium silicate. Dissolution of these products upon contact with water generated heat that promoted cement’s self-degradation. Thus, CMC of high molecular weight rendered two important features to the water-catalyzed self-degradation of heated cement: One was the high heat energy generated in exothermic reactions in cement; the other was the introduction of extensive porosity into cement.

Small heat-shock proteins and leaf cooling capacity account for the unusual heat tolerance of the central spike leaves in Agave tequilana var. Weber.

Science.gov (United States)

Luján, Rosario; Lledías, Fernando; Martínez, Luz María; Barreto, Rita; Cassab, Gladys I; Nieto-Sotelo, Jorge

2009-12-01

Agaves are perennial crassulacean acid metabolism (CAM) plants distributed in tropical and subtropical arid environments, features that are attractive for studying the heat-shock response. In agaves, the stress response can be analysed easily during leaf development, as they form a spirally shaped rosette, having the meristem surrounded by folded leaves in the centre (spike) and the unfolded and more mature leaves in the periphery. Here, we report that the spike of Agave tequilana is the most thermotolerant part of the rosette withstanding shocks of up to 55 degrees C. This finding was inconsistent with the patterns of heat-shock protein (Hsp) gene expression, as maximal accumulation of Hsp transcripts was at 44 degrees C in all sectors (spike, inner, middle and outer). However, levels of small HSP (sHSP)-CI and sHSP-CII proteins were conspicuously higher in spike leaves at all temperatures correlating with their thermotolerance. In addition, spike leaves showed a higher stomatal density and abated more efficiently their temperature several degrees below that of air. We propose that the greater capacity for leaf cooling during the day in response to heat stress, and the elevated levels of sHSPs, constitute part of a set of strategies that protect the SAM and folded leaves of A. tequilana from high temperatures.

Behaviour of TEM metal grids during in-situ heating experiments.

Science.gov (United States)

Zhang, Zaoli; Su, Dangsheng

2009-05-01

The stability of Ni, Cu, Mo and Au transmission electron microscope (TEM) grids coated with ultra-thin amorphous carbon (alpha-C) or silicon monoxide film is examined by in-situ heating up to a temperature in the range 500-850 degrees C in a transmission electron microscope. It is demonstrated that some grids can generate nano-particles either due to the surface diffusion of metal atoms on amorphous film or due to the metal evaporation/redeposition. The emergence of nano-particles can complicate experimental observations, particularly in in-situ heating studies of dynamic behaviours of nano-materials in TEM. The most widely used Cu grid covered with amorphous carbon is unstable, and numerous Cu nano-particles start to form once the heating temperature reaches 600 degrees C. In the case of Ni grid covered with alpha-C film, a large number of Ni nano-crystals occur immediately when the temperature approaches 600 degrees C, accompanied by the graphitization of amorphous carbon. In contrast, both Mo and Au grids covered with alpha-C film exhibit good stability at elevated temperature, for instance, up to 680 and 850 degrees C for Mo and Au, respectively, and any other metal nano-particles are detected. Cu grid covered Si monoxide thin film is stable up to 550 degrees C, but Si nano-crystals appear under intensive electron beam. The generated nano-particles are well characterized by spectroscopic techniques (EDXS/EELS) and high-resolution TEM. The mechanism of nano-particle formation is addressed based on the interactions between the metal grid and the amorphous carbon film and on the sublimation of metal.

[Effect of heat treatment on the structure of a Cu-Zn-Al-Ni system dental alloy].

Science.gov (United States)

Guastaldi, A C; Adorno, A T; Beatrice, C R; Mondelli, J; Ishikiriama, A; Lacefield, W

1990-01-01

This article characterizes the structural phases present in the copper-based metallic alloy system "Cu-Zn-Al-Ni" developed for dental use, and relates those phases to other properties. The characterization was obtained after casting (using the lost wax process), and after heat treatment. In order to obtain better corrosion resistance by changing the microstructure, the castings were submitted to 30, 45 and 60 minutes of heat treatment at the following temperatures: 750 degrees C, 800 degrees C, and 850 degrees C. The various phases were analyzed using X-ray diffraction and scanning electron microscopy (SEM). The results after heat treatment showed a phase (probably Cu3Al), that could be responsible for the improvement in the alloy's resistance to corrosion as compared to the as-cast structure.

Quantum-limited heat conduction over macroscopic distances

Science.gov (United States)

Partanen, Matti; Tan, Kuan Yen; Govenius, Joonas; Lake, Russell E.; Mäkelä, Miika K.; Tanttu, Tuomo; Möttönen, Mikko

2016-05-01

The emerging quantum technological apparatuses, such as the quantum computer, call for extreme performance in thermal engineering. Cold distant heat sinks are needed for the quantized electric degrees of freedom owing to the increasing packaging density and heat dissipation. Importantly, quantum mechanics sets a fundamental upper limit for the flow of information and heat, which is quantified by the quantum of thermal conductance. However, the short distance between the heat-exchanging bodies in the previous experiments hinders their applicability in quantum technology. Here, we present experimental observations of quantum-limited heat conduction over macroscopic distances extending to a metre. We achieved this improvement of four orders of magnitude in the distance by utilizing microwave photons travelling in superconducting transmission lines. Thus, it seems that quantum-limited heat conduction has no fundamental distance cutoff. This work establishes the integration of normal-metal components into the framework of circuit quantum electrodynamics, which provides a basis for the superconducting quantum computer. Especially, our results facilitate remote cooling of nanoelectronic devices using faraway in situ-tunable heat sinks. Furthermore, quantum-limited heat conduction is important in contemporary thermodynamics. Here, the long distance may lead to ultimately efficient mesoscopic heat engines with promising practical applications.

Parametric optimization and heat transfer analysis of a dual loop ORC (organic Rankine cycle) system for CNG engine waste heat recovery

International Nuclear Information System (INIS)

Yang, Fubin; Zhang, Hongguang; Yu, Zhibin; Wang, Enhua; Meng, Fanxiao; Liu, Hongda; Wang, Jingfu

2017-01-01

In this study, a dual loop ORC (organic Rankine cycle) system is adopted to recover exhaust energy, waste heat from the coolant system, and intercooler heat rejection of a six-cylinder CNG (compressed natural gas) engine. The thermodynamic, heat transfer, and optimization models for the dual loop ORC system are established. On the basis of the waste heat characteristics of the CNG engine over the whole operating range, a GA (genetic algorithm) is used to solve the Pareto solution for the thermodynamic and heat transfer performances to maximize net power output and minimize heat transfer area. Combined with optimization results, the optimal parameter regions of the dual loop ORC system are determined under various operating conditions. Then, the variation in the heat transfer area with the operating conditions of the CNG engine is analyzed. The results show that the optimal evaporation pressure and superheat degree of the HT (high temperature) cycle are mainly influenced by the operating conditions of the CNG engine. The optimal evaporation pressure and superheat degree of the HT cycle over the whole operating range are within 2.5–2.9 MPa and 0.43–12.35 K, respectively. The optimal condensation temperature of the HT cycle, evaporation and condensation temperatures of the LT (low temperature) cycle, and exhaust temperature at the outlet of evaporator 1 are kept nearly constant under various operating conditions of the CNG engine. The thermal efficiency of the dual loop ORC system is within the range of 8.79%–10.17%. The dual loop ORC system achieves the maximum net power output of 23.62 kW under the engine rated condition. In addition, the operating conditions of the CNG engine and the operating parameters of the dual loop ORC system significantly influence the heat transfer areas for each heat exchanger. - Highlights: • A dual loop ORC system is adopted to recover the waste heat of a CNG engine. • Parametric optimization and heat transfer analysis are

Thermodynamic analysis on theoretical models of cycle combined heat exchange process: The reversible heat exchange process

International Nuclear Information System (INIS)

Zhang, Chenghu; Li, Yaping

2017-01-01

Concept of reversible heat exchange process as the theoretical model of the cycle combined heat exchanger could be useful to determine thermodynamics characteristics and the limitation values in the isolated heat exchange system. In this study, the classification of the reversible heat exchange processes is presented, and with the numerical method, medium temperature variation tendency and the useful work production and usage in the whole process are investigated by the construction and solution of the mathematical descriptions. Various values of medium inlet temperatures and heat capacity ratio are considered to analyze the effects of process parameters on the outlet temperature lift/drop. The maximum process work transferred from the Carnot cycle region to the reverse cycle region is also researched. Moreover, influence of the separating point between different sub-processes on temperature variation profile and the process work production are analyzed. In addition, the heat-exchange-enhancement-factor is defined to study the enhancement effect of the application of the idealized process in the isolated heat exchange system, and the variation degree of this factor with process parameters change is obtained. The research results of this paper can be a theoretical guidance to construct the cycle combined heat exchange process in the practical system. - Highlights: • A theoretical model of Cycle combined heat exchange process is proposed. • The classification of reversible heat exchange process are presented. • Effects of Inlet temperatures and heat capacity ratio on process are analyzed. • Process work transmission through the whole process is studied. • Heat-exchange-enhancement-factor can be a criteria to express the application effect of the idealized process.

Twin solution calorimeter determines heats of formation of alloys at high temperatures

Science.gov (United States)

Darby, J. B., Jr.; Kleb, R.; Kleppa, O. J.

1968-01-01

Calvert-type, twin liquid metal solution calorimeter determines the heats of formation of transition metal alloys at high temperatures. The twin differential calorimeter measures the small heat effects generated over extended periods of time, has maximum operating temperature of 1073 degrees K and an automatic data recording system.

Structural changes in deashed coals induced by heat treatment; Kanetsu shori ni yoru dakkaitan no kozo henka

Energy Technology Data Exchange (ETDEWEB)

Sugano, M.; Sekita, M.; Muramatsu, Y.; Mashimo, K.; Wainai, T. [Nihon University, Tokyo (Japan). College of Science and Technology

1996-10-28

Change in structures of 3 kinds of coals with different coal ranks and their deashed coals was studied by heat treatment below 200{degree}C. In experiment, crushed Adaro, Taiheiyo and Huaibei coals below 200mesh and their deashed coals were used as specimens. The coal and deashed coal specimens dried in vacuum at 110{degree}C for 3 hours were filled into an autoclave, and the heat-treated coal specimens were prepared by holding them under initial nitrogen pressure of 2kg/cm{sup 2} at a fixed temperature for 30min. Extraction using pyridine as solvent, volumetric swelling using methanol or benzene as solvent, and measurement of the amount of carboxyl and phenolic hydroxyl functional groups were conducted for these coal specimens. The experimental results are as follows. Huaibei coal has developed aromatic ring structure, and its structure is hardly affected by heat treatment. The oxygen containing functional groups decrease by heat treatment over 100{degree}C in Adaro coal and 150{degree}C in Taiheiyo coal, and PS, MQ and BQ also decrease due to aggregation between molecules. 5 refs., 2 figs.

The system Cu-Rh-S at 900 degrees, 700 degrees, 540 degrees and 500 degrees C

DEFF Research Database (Denmark)

Karup-Møller, Sven; Makovicky, E.

2007-01-01

Phase relations in the dry condensed system Cu-Rh-S were determined at 900, 700, 540 and 500 degrees C. At 900 degrees C, the system contains digenite, four rhodium sulfides (Rh17S15, Rh3S4, Rh2S3 and RhS similar to 3), three ternary sulfides (CuRh2S4, CuxRhS3+x and a fibrous sulfide in the range...

Maximum skin hyperaemia induced by local heating: possible mechanisms.

Science.gov (United States)

Gooding, Kim M; Hannemann, Michael M; Tooke, John E; Clough, Geraldine F; Shore, Angela C

2006-01-01

Maximum skin hyperaemia (MH) induced by heating skin to > or = 42 degrees C is impaired in individuals at risk of diabetes and cardiovascular disease. Interpretation of these findings is hampered by the lack of clarity of the mechanisms involved in the attainment of MH. MH was achieved by local heating of skin to 42-43 degrees C for 30 min, and assessed by laser Doppler fluximetry. Using double-blind, randomized, placebo-controlled crossover study designs, the roles of prostaglandins were investigated by inhibiting their production with aspirin and histamine, with the H1 receptor antagonist cetirizine. The nitric oxide (NO) pathway was blocked by the NO synthase inhibitor, NG-nitro-L-arginine methyl esther (L-NAME), and enhanced by sildenafil (prevents breakdown of cGMP). MH was not altered by aspirin, cetirizine or sildenafil, but was reduced by L-NAME: median placebo 4.48 V (25th, 75th centiles: 3.71, 4.70) versus L-NAME 3.25 V (3.10, 3.80) (p = 0.008, Wilcoxon signed rank test). Inhibition of NO production (L-NAME) resulted in a more rapid reduction in hyperaemia after heating (p = 0.011), whereas hyperaemia was prolonged in the presence of sildenafil (p = 0.003). The increase in skin blood flow was largely confined to the directly heated area, suggesting that the role of heat-induced activation of the axon reflex was small. NO, but not prostaglandins, histamine or an axon reflex, contributes to the increase in blood flow on heating and NO is also a component of the resolution of MH after heating. Copyright 2006 S. Karger AG, Basel.

Study of high energy ion loss during hydrogen minority heating in TFTR

International Nuclear Information System (INIS)

Park, J.; Zweben, S.J.

1994-03-01

High energy ion loss during hydrogen minority ICRF heating is measured and compared with the loss of the D-D fusion products. During H minority heating a relatively large loss of high energy ions is observed at 45 degrees below the outer midplane, with or without simultaneous NBI heating. This increase is most likely due to a loss of the minority tail protons, a possible model for this process is described

Design and performance tests of gas circulation heating of JT-60U vacuum vessel

International Nuclear Information System (INIS)

Yotsuga, M.; Masuzaki, T.; Sago, H.; Nishikane, M.; Uchikawa, T.; Iritani, Y.; Murakami, T.; Horiike, H.; Neyatani, Y.; Ninomiya, H.; Matsukawa, M.; Ando, T.; Miyachi, I.

1992-01-01

This paper reports that in the final stage of construction of the upgraded JT-60 device (JT-60U), baking tests of the vacuum vessel was performed. The vessel torus was heated-up to 300 degrees C by means of the nitrogen gas circulation system and electric heaters mounted on the outboard solid wall of the vessel. The design of the gas flow channels inside the double-wall structure of the vessel was done based on flow model tests, fluid analysis, and flow network analysis. The results of the baking tests were satisfactory. In maintaining 300 degrees C bake-out temperature, required heating power of the gas circulation system and outboard heaters was 520kW and 50kW, respectively. The temperature distribution over the vessel wall was within 300 ± 30 degrees C. It was also shown or suggested that heat-up and cool-down time is about 30 hours. The baking tests data have been reflected on operations for plasma experiments

Fragmented Encounters, Social Slippages: Lin Huiyin's "In Ninety-Nine Degree Heat"

Directory of Open Access Journals (Sweden)

Carles Prado-Fonts

2010-01-01

Full Text Available The article reads Lin Huiyin’s short story “In Ninety-Nine Degree Heat” (1934 in relation to the context of 1930s China, as an innovative literary work which combines elements from both the Chinese and the Western traditions, and as a text which informs readers not only of the problematic of class and gender issues in 1930s Chinese society but also of the context of the liuxuesheng who returns to China –like Lin Huiyin herself. Focusing on questions like otherness, representation, and encounters, the essay analyzes how the episodic narrative structure of Lin’s short story echoes social and representational discourses in post-May Fourth China, at the same time that it explores issues such as social inequality, otherness and alienation, which were crucial to the liuxuesheng, and which reflect Lin’s own experience as a returned and alienated liuxuesheng at the time.

The Zr-Ti-Cr system. Equilibria at 900 and 1100 C degrees

International Nuclear Information System (INIS)

Arico, Sergio F.; Gribaudo, Luis M.

2003-01-01

Main contributions to the knowledge of the ternary system Zr-Ti-Cr were published in the sixties. Stability domains of phases at temperatures between 500 and 1400 C degrees were there presented. Here, results related to the phase diagram at 900 and 1100 C degrees are informed. Three alloys with 40 at.% Cr and different Zr/Ti ratios and one more, richer in Cr, were elaborated. Specimens of the alloys were heat treated 1000 and 800 h at 900 and 1100 C degrees respectively. Phase characterizations were performed by optic metallography and X-ray diffraction analysis. Compositions were determined by microprobe. Alloys with 40 at.% Cr at both temperatures have biphasic equilibria between the intermetallic Laves phase AB 2 and the body-centered cubic solid solution containing principally zirconium and titanium. The Cr-rich alloy presents equilibrium of the AB 2 compound and the Cr-rich solid solution. Results of the present and previous works are used in order to propose new isothermal sections at 900 and 1100 C degrees. (author)

Measurements of average heat-transfer and friction coefficients for subsonic flow of air in smooth tubes at high surface and fluid temperatures

Science.gov (United States)

Humble, Leroy V; Lowdermilk, Warren H; Desmon, Leland G

1951-01-01

An investigation of forced-convection heat transfer and associated pressure drops was conducted with air flowing through smooth tubes for an over-all range of surface temperature from 535 degrees to 3050 degrees r, inlet-air temperature from 535 degrees to 1500 degrees r, Reynolds number up to 500,000, exit Mach number up to 1, heat flux up to 150,000 btu per hour per square foot, length-diameter ratio from 30 to 120, and three entrance configurations. Most of the data are for heat addition to the air; a few results are included for cooling of the air. The over-all range of surface-to-air temperature ratio was from 0.46 to 3.5.

Fluidics and heat generation of Alcon Infiniti and Legacy, Bausch & Lomb Millennium, and advanced medical optics sovereign phacoemulsification systems.

Science.gov (United States)

Floyd, Michael S; Valentine, Jeremy R; Olson, Randall J

2006-09-01

To study heat generation, vacuum, and flow characteristics of the Alcon Infiniti and Bausch & Lomb Millennium with results compared with the Alcon Legacy and advanced medical optics (AMO) Sovereign machines previously studied. Experimental study. Heat generation with continuous ultrasound was determined with and without a 200-g weight. Flow and vacuum were determined from 12 to 40-ml/min in 2-ml/min steps. The impact of a STAAR Cruise Control was also tested. Millennium created the most heat/20% of power (5.67 +/- 0.51 degrees C unweighted and 6.80 +/- 0.80 degrees C weighted), followed by Sovereign (4.59 +/- 0.70 degrees C unweighted and 5.65 +/- 0.72 degrees C weighted), Infiniti (2.79 +/- 0.62 degrees C unweighted and 3.96 +/- 0.31 degrees C weighted), and Legacy (1.99 +/- 0.49 degrees C unweighted and 4.27 +/- 0.76 degrees C weighted; P Infiniti vs Legacy, both weighted). Flow studies revealed that Millennium Peristaltic was 17% less than indicated (P < .0001 to all other machines), and all other machines were within 3.5% of indicated. Cruise Control decreased flow by 4.1% (P < .0001 for same machine without it). Millennium Venturi had the greatest vacuum (81% more than the least Sovereign; P < .0001), and Cruise Control increased vacuum in a peristaltic machine 35% more than the Venturi system (P < .0001). Percent power is not consistent in regard to heat generation, however, flow was accurate for all machines except Millennium Peristaltic. Restriction with Cruise Control elevates unoccluded vacuum to levels greater than the Venturi system tested.

The Relation between Heat strain and hydration status among

Directory of Open Access Journals (Sweden)

Somayeh Bolghanabadi

2016-12-01

Full Text Available Introduction: during the physical activity in hot environments, sweating with evaporation, the important physiological response of the body  increases which can be lead to dehydration . Long-term water shortages could adversely affect vital organs. The aim of this study was to determine heat stress and dehydration status of workers in hot workplaces. Methods: This cross sectional study was done on 90 workers of workers in sugar factory which were exposed to heat. Heart rate and oral temperature were respectively measured using a heart rate meter and an oral thermometer. WBGT index was recorded and the HSSI questionnaire was completed simultaneously, in order to assess dehydration level was measured of refractometer. Data obtained from this study were analyzed using compare means and t-test, paired t-test tests by SPSS 20 software Results: Heat stress exceeded the national and international recommended limits based on the WBGT index in 44% of cases of workstations. According to this study, 8.5% of our population had some degree of dehydration.63.4% of them were significantly dehydrated (urine SG>1.020 and 28% of them were severely dehydrated (urine SG>1.030 and the mean specific gravity was 1.025±0.043 The correlations between heat strains, Urine Density and heat stress including oral temperature, heart rate were significant(p<0.05. Conclusion: A high percentage of the study population had some degree of dehydration that based on the results is worrying. It seems that planning in order to control of heat stresses by replace drinking is necessary.

Technological and Thermal Properties of Thermoplastic Composites Filled with Heat-treated Alder Wood

Directory of Open Access Journals (Sweden)

Mürşit Tufan

2016-02-01

Full Text Available This study investigated the effect of heat-treated wood content on the water absorption, mechanical, and thermal properties of wood plastic composites (WPCs. The WPCs were produced from various loadings (30, 40, and 50 wt% of heat-treated and untreated alder wood flours (Alnus glutinosa L. using high-density polyethylene (HDPE with 3 wt% maleated polyethylene (MAPE coupling agent. All WPC formulations were compression molded into a hot press for 3 min at 170 ºC. The WPCs were evaluated using mechanical testing, Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, and differential scanning calorimetry (DSC. The mechanical property values of the WPC specimens decreased with increasing amounts of the heat-treated wood flour, except for the tensile modulus values. The heat treatment of alder wood slightly increased the thermal stability of the WPCs compared with the reference WPCs. The crystallization degree (Xc and the enthalpy of crystallization of the WPCs slightly decreased with increasing content of the heat-treated wood flour. However, all WPCs containing the heat-treated alder wood flour showed a higher crystallinity degree than that of the virgin HDPE.

Surface wettability and subcooling on nucleate pool boiling heat transfer

Science.gov (United States)

Suroto, Bambang Joko; Kohno, Masamichi; Takata, Yasuyuki

2018-02-01

The effect of varying surface wettabilities and subcooling on nucleate pool boiling heat transfer at intermediate heat flux has been examined and investigated. The experiments were performed using pure water as the working fluid and subcooling ranging from 0, 5 and 10 K, respectively. The three types of heat transfer block were used that are bare surface/hydrophilic (polished copper), superhydrophilic/TiO2-coated on copper and hydrophobic/PTFE surface. The experimental results will be examined by the existing model. The results show that the heat transfer performance of surfaces with PTFE coating is better at low heat flux. While for an intermediate heat flux, superhydrophilic surface (TiO2) is superior compared to hydrophilic and hydrophobic surfaces. It is observed that the heat transfer performance is decreasing when the sub cooling degree is increased.

Sensitization to heat by the polyamines and their analogs

Energy Technology Data Exchange (ETDEWEB)

Fuller, D.J.; Gerner, E.W.

1983-07-01

The polyamines putrescine, spermidine, and spermine have been shown to sensitize Chinese hamster ovary (CHO) cells to the cytotoxic effects of elevated temperatures. This sensitization occurs in the order spermine greater than spermidine greater than putrescine. A series of homologs of the diamine putrescine demonstrated little variance in the degree of potentiation until a chain length equivalent to that of spermidine was employed (1,8-diaminooctane). Two compounds bearing structural similarities to spermidine gave rather different results when combined with heat. Methylglyoxal bis(guanylhydrazone) (MGBG), an antiproliferative drug, sensitized cells to heat, while S-2-(3-aminopropylamino)-ethyl phosphoric acid (WR-2721), a radioprotector, had no measureable effect on 43 degrees C-induced cytotoxicity. Together, these results point out the primary importance of two terminal amino groups separated by either carbon, or carbon and nitrogen, atoms in an aliphatic chain in the observed sensitization of heat-induced cytotoxicity by polyamines. These data suggest specific dimensional characteristics of the presumed negatively charged structure(s) with which the polyamines are interacting to elicit this effect.

Effects of heat on physicochemical properties of whey protein-stabilised emulsions

NARCIS (Netherlands)

Sliwinski, E.L.; Zoet, F.D.; Boekel, van M.A.J.S.; Wouters, J.T.M.; Roubos-van den Hil, P.J.

2003-01-01

The effect of heating has been studied for whey protein-stabilised oil-in-water emulsions (25.0% (w/w) soybean oil, 3.0% (w/w) whey protein isolate, pH 7.0). These emulsions were heated between 55 and 95 degreesC as a function of time and the effect on particle size distribution, adsorbed protein

Effects of roasting, blanching, autoclaving, and microwave heating on antigenicity of almond (Prunus dulcis L.) proteins.

Science.gov (United States)

Venkatachalam, M; Teuber, S S; Roux, K H; Sathe, S K

2002-06-05

Whole, unprocessed Nonpareil almonds were subjected to a variety of heat processing methods that included roasting (280, 300, and 320 degrees F for 20 and 30 min each; and 335 and 350 degrees F for 8, 10, and 12 min each), autoclaving (121 degrees C, 15 psi, for 5, 10, 15, 20, 25, and 30 min), blanching (100 degrees C for 1, 2, 3, 4, 5, and 10 min), and microwave heating (1, 2, and 3 min). Proteins were extracted from defatted almond flour in borate saline buffer, and immunoreactivity of the soluble proteins (normalized to 1 mg protein/mL for all samples) was determined using enzyme linked immunosorbent assay (ELISA). Antigenic stability of the almond major protein (amandin) in the heat-processed samples was determined by competitive inhibition ELISA using rabbit polyclonal antibodies raised against amandin. Processed samples were also assessed for heat stability of total antigenic proteins by sandwich ELISA using goat and rabbit polyclonal antibodies raised against unprocessed Nonpareil almond total protein extract. ELISA assays and Western blotting experiments that used both rabbit polyclonal antibodies and human IgE from pooled sera indicated antigenic stability of almond proteins when compared with that of the unprocessed counterpart.

Performance in cooling mode of a heat pump using panels with PV cells as the condenser; Taiyo denchitsuki panel wo gyoshukuki to shita heat pump no reibo unten

Energy Technology Data Exchange (ETDEWEB)

Kawamura, T; Ito, S; Miura, N [Kanagawa Institute of Technology, Kanagawa (Japan); Fujita, M [Chubu Electric Power Co. Inc., Nagoya (Japan)

1996-10-27

Comparison was made between heat pumps in cooling operation, one having two panels provided with solar cells, the second having an air-cooled heat exchanger alone, and the third having a series connection of a panel unit and air-cooled heat exchanger, all serving as condenser. The results are shown below. In the case of two-panel-unit condenser, there is a difference ({Delta}t) of 15{degree}C between the daytime free air temperature and condensing temperature but, with decreased insolation, free air temperature, and wind speed in the evening, the {Delta}t lowered to approximately 8{degree}C while the COP (coefficient of performance) increased from 2.4 to 3.3. On a cloudy day in summer, the two-panel-unit condenser had a {Delta}t of 13.9{degree}C and a COP of 3.1. In the case of the series-connection condenser, the {Delta}t was approximately 8{degree}C and the COP was 3.5. The COP of the two-panel-unit condenser was lower than that of the air-cooled heat exchanger by 9% at an insolation of 442W/m{sup 2} but it rose to 12% in the absence of insolation. The COP of the two-panel-unit condenser was higher than that of a one-panel-unit condenser by 17%. When an insulator plate was attached to the back of a panel, the {Delta}t increased but the COP decreased by 14%. In the case of the series-connection condenser, the COP increased by 6% in the absence of the insulator plate. 2 refs., 9 figs.

When Graduate Degrees Prostitute the Educational Process: Degrees Gone Wild

Science.gov (United States)

Lumadue, Richard T.

2006-01-01

Graduate degrees prostitute the educational process when they are sold to consumers by unaccredited degree/diploma mills as being equivalent to legitimate, bona-fide degrees awarded by accredited graduate schools. This article carefully analyzes the serious problems of bogus degrees and their association with the religious higher education…

Heat savings in energy systems with substantial distributed generation

DEFF Research Database (Denmark)

Østergaard, PA

2003-01-01

In Denmark, the integration of wind power is affected by a large amount of cogeneration of heat and power. With ancillary services supplied by large-scale condensation and combined heat and power (CHP) plants, a certain degree of large-scale generation is required regardless of momentary wind input......, if a certain production is required regardless of whether over-all electricity generation is sufficient. This article analyses this and although heat savings do have a negative impact on the amount of wind power the system may integrate a given moment in certain cases, associated fuel savings are notable...

Interactions between goethite particles subjected to heat treatment

DEFF Research Database (Denmark)

Madsen, Daniel Esmarch; Hansen, Mikkel Fougt; Koch, C.B.

2008-01-01

We have studied the effect of heating on the magnetic properties of particles of nanocrystalline goethite by use of Mossbauer spectroscopy. Heating at 150 degrees C for 24 h leads to a change in the quadrupole shift in the low-temperature spectra, indicating a rotation of the sublattice...... magnetization directions. Fitting of quantiles, derived from the asymmetrically broadened spectra between 80 and 300 K, to the superferromagnetism model indicates that this change is due to a stronger magnetic coupling between the particles....

Effect of furnace type and ceramming heat treatment conditions on the biaxial flexural strength of a canasite glass-ceramic.

Science.gov (United States)

Johnson, A; Shareef, M Y; van Noort, R; Walsh, J M

2000-07-01

To assess the effect of different heat treatment conditions when using two different furnace types on the biaxial flexural strength (BFS) of a fluorcanasite castable glass-ceramic. Two furnace types, one a programmable furnace (PF), the other a dental laboratory burnout furnace (DLF), were used with various ceramming times to determine their effect on the BFS of a fluorcanasite castable glass-ceramic. The glass-ceramic material was cast to produce discs of 12 mm diameter and 2 mm thickness using the lost wax casting process (n = 80). After casting, both furnace types were used to ceram the discs. Half the discs were not de-vested from the casting ring before ceramming but cerammed in situ (DLF) and half were de-vested before ceramming (PF). All the discs were given a nucleation heat treatment at 520 degrees C for 1 h and then cerammed at 860 degrees C using four heat soak times (0.5, 1, 2 and 3 h). The DLF furnace had a rate of climb of 13 degrees C/min and the PF furnace had a rate of climb of 5 degrees C/min to 520 degrees C and 3 degrees C/min to 860 degrees C. After ceramming the discs were de-vested and the BFS determined using a Lloyd 2000R tester. The maximum BFS values seen for both furnace types were almost identical (280 MPa), but were achieved at different heat soak times (1 h DLF, and 2 h PF). The only significant differences in BFS values for the two furnaces were between the 0.5 and 2 h heat soak times (p < or = 0.05). Individual differences were seen between results obtained from each furnace type/heat soak times evaluated (p < or = 0.05). Already available dental laboratory burnout furnaces can be used to ceram fluorcanasite glass-ceramic castings to the same BFS values as more expensive and slower specialist programmable furnaces.

Forced convective and subcooled flow boiling heat transfer to pure water and n-heptane in an annular heat exchanger

International Nuclear Information System (INIS)

Peyghambarzadeh, S.M.; Sarafraz, M.M.; Vaeli, N.; Ameri, E.; Vatani, A.; Jamialahmadi, M.

2013-01-01

Highlights: ► The cooling performance of water and n-heptane is compared during subcooled flow boiling. ► Although n-heptane leaves the heat exchanger warmer it has a lower heat transfer coefficient. ► Flow rate, heat flux and degree of subcooling have direct effect on heat transfer coefficient. ► The predictions of some correlations are evaluated against experimental data. - Abstract: In this research, subcooled flow boiling heat transfer coefficients of pure n-heptane and distilled water at different operating conditions have been experimentally measured and compared. The heat exchanger consisted of vertical annulus which is heated from the inner cylindrical heater with variable heat flux (less than 140 kW/m 2 ). Heat flux is varied so that two different flow regimes from single phase forced convection to nucleate boiling condition are created. Meanwhile, liquid flow rate is changed in the range of 2.5 × 10 −5 –5.8 × 10 −5 m 3 /s to create laminar up to transition flow regimes. Three subcooling levels including 10, 20 and 30 °C are also considered. Experimental results demonstrated that subcooled flow boiling heat transfer coefficient increases when higher heat flux, higher liquid flow rate and greater subcooling level are applied. Furthermore, influence of the operating conditions on the bubbles generation on the heat transfer surface is also discussed. It is also shown that water is better cooling fluid in comparison with n-heptane

The influence of heat treatments on several types of base-metal removable partial denture alloys.

Science.gov (United States)

Morris, H F; Asgar, K; Rowe, A P; Nasjleti, C E

1979-04-01

Four removable partial denture alloys, Vitallium (Co-Cr alloy), Dentillium P.D. (Fe-Cr alloy), Durallium L.G. (Co-Cr-Ni alloy), and Ticonium 100 (Ni-Cr alloy), were evaluated in the as-cast condition and after heat treatment for 15 minutes at 1,300 degrees, 1,600 degrees, 1,900 degrees, and 2,200 degrees F followed by quenching in water. The following properties were determined and compared for each alloy at each heat treatment condition: the yield strengths at 0.01%, 0.1%, and 0.2% offsets, the ultimate tensile strength, the percent elongation, the modulus of elasticity, and the Knoop microhardness. The results were statistically analyzed. Photomicrographs were examined for each alloy and test condition. The following conclusions were made: 1. The "highest values" were exhibited by the as-cast alloy. 2. Heat treatment of the partial denture alloys tested resulted in reductions in strength, while the elongations varied. This study demonstrates that, in practice, one should avoid (a) prolonged "heat-soaking" while soldering and (b) grinding or polishing of the casting until the alloy is "red hot". 3. Durallium L.G. was the least affected by the various heat treatment conditions. 4. Conventional reporting of the yield strength at 0.2% offset, the ultimate tensile strength, and percent elongation are not adequate to completely describe and compare the mechanical behavior of alloys. The reporting of the yield strength at 0.01% offset, in addition to the other reported properties, will provide a more complete description of the behavior of the dental alloys.

A theory of burn-out in heated channels at low mass velocities

International Nuclear Information System (INIS)

Randles, J.

1963-01-01

At low coolant mass velocities the fraction by weight of vapour flowing out of heated channels can become extremely large (∼ 90%). Consequently, the dominating feature of burn-out at small flow rates is that it occurs at high vapour qualities. For such a high degree of evaporation, the induced turbulence is very strong and the liquid phase is dispersed into a spray of droplets. By the application of the first law of thermodynamics and some basic relationships of turbulence theory to this spray, it is shown how an expression for the critical heat flux can be derived. By comparing this expression with the data from burn-out measurements on uniformly heated channels, reasonably good agreement is obtained. It is demonstrated that eddy slip and channel geometry are extremely important in the determination of the level of turbulence in the droplet motion. Having thus established a reasonable degree of plausibility for the theory, it is applied to channels heated by a chopped cosine form of power distribution. The results indicate that the effect of the axial variation of the power on the burnout heat flux can be described in a simple manner. (author)

Power generation from low-temperature heat source

Energy Technology Data Exchange (ETDEWEB)

Lakew, Amlaku Abie

2012-07-01

The potential of low-temperature heat sources for power production has been discussed for decades. The diversity and availability of low-temperature heat sources makes it interesting for power production. The thermodynamic power cycle is one of the promising technologies to produce electricity from low-temperature heat sources. There are different working fluids to be used in a thermodynamic power cycle. Working fluid selection is essential for the performance of the power cycle. Over the last years, different working fluid screening criteria have been used. In broad speaking the screening criteria can be grouped as thermodynamic performance, component size requirement, economic performance, safety and environmental impact. Screening of working fluids at different heat source temperatures (80-200 Celsius degrees) using thermodynamic performance (power output and exergy efficiency) and component size (heat exchanger and turbine) is investigated. It is found that the 'best' working fluid depends on the criteria used and heat source temperature level. Transcritical power cycles using carbon dioxide as a working fluid is studied to produce power at 100 Celsius degrees. Carbon dioxide is an environmentally friendly refrigerant. The global warming potential of carbon dioxide is 1. Furthermore, because of its low critical temperature (31 Celsius degrees), carbon dioxide can operate in a transcritical power cycle for lower heat source temperatures. A transcritical configuration avoids the problem of pinching which otherwise would happened in subcritical power cycle. In the process, better temperature matching is achieved and more heat is extracted. Thermodynamic analysis of transcritical cycle is performed; it is found that there is an optimal operating pressure for highest net power output. The pump work is a sizable fraction of the work produced by the turbine. The effect of efficiency deterioration of the pump and the turbine is compared. When the

An experimental study of heat transfer and pressure drop of two-phas flow in an inclined annular channel

International Nuclear Information System (INIS)

Khattab, M.S.; Mariy, A.H.; Hilal, M.M.; El-Morshdy, S.E.

1999-01-01

The phenomena of two-phase flow through horizontal, vertical and inclined tubes has many engineering applications in heat exchangers, boilers, nuclear reactors, steam generators and refrigerators..etc. In the present investigation, two-phase flow heat transfer and pressure drop have been experimentally studied at different orientations of an annular channel test section subjected to uniform heat flux. The annular test section was internally heated by a DC power supply. The experimental investigation has been classified onto three steady state groups of (heat flux, mass flux, and inlet temperature). The first group was at 522.41 kw/m 2 , 310 kg/m 2 s and 89.4 degree C; the second was at 779.72 kw/m 2 , 507 Hg/m 2 s and 94.3 degree C and the third was at 1019.97 kw/m 2 s 701 kg/m 2 100 degree C. The effect of inclination on the two-phase heat transfer coefficient and pressure drop are presented and discussed. The present experimental results are compared with some existing correlations for two phase flow boiling heat transfer in horizontal and vertical tubes at their range of validity. The comparison shows a good agreement. The behavior of the two-phase mean heat transfer coefficient shows a small enhancement due to inclination from horizontal to vertical orientation. The enhancement factor relating the two-phase heat transfer coefficient with the inclination angle is predicted

Differential heat shock response of primary human cell cultures and established cell lines

DEFF Research Database (Denmark)

Richter, W W; Issinger, O G

1986-01-01

degrees C treatment, whereas in immortalized cell lines usually 90% of the cells were found in suspension. Enhanced expression of the major heat shock protein (hsp 70) was found in all heat-treated cells. In contrast to the primary cell cultures, established and transformed cell lines synthesized...

Direct high-temperature ohmic heating of metals as liquid pipes.

Science.gov (United States)

Grosse, A V; Cahill, J A; Liddell, W L; Murphy, W J; Stokes, C S

1968-05-03

When a sufficiently high electric current is passed through a liquid metal, the electromagnetic pressure pinches off the liquid metal and interrupts the flow of current. For the first time the pinch effect has been overcome by use of centrifugal acceleration. By rotation of a pipe of liquid metal, tin or bismuth or their alloys, at sufficiently high speed, it can be heated electrically without intermission of the electric current. One may now heat liquid metallic substances, by resistive (ohmic) heating, to 5000 degrees K and perhaps higher temperatures.

Experimental study of conjugate heat transfer from liquid metal layer cooled by overlying freon

International Nuclear Information System (INIS)

Cho, J.S.; Suh, K.Y.; Chung, C.H.; Park, R.J.; Kim, S.B.

2001-01-01

Steady-state and transient experiments were performed for the heat transfer from the liquid metal pool with overlying Freon (R113) coolant in the process of boiling. The simulant molten pool material is tin (Sn) with the melting temperature of 232 Celsius degrees. The metal pool is heated from the bottom surface and the coolant is injected onto the molten metal pool. Tests were conducted under the condition of the bottom surface heating in the test section and the forced convection of the R113 coolant being injected onto the molten metal pool. The bottom heating condition was varied from 8 kW to 14 kW. The temperature distributions of the metal layer and coolant were obtained in the steady-state experiment. The boiling mechanism of the R113 coolant was changed from the nucleate boiling to film boiling in the transient experiment. The critical heat flux (CHF) phenomenon was observed during the transition from the nucleate boiling to the film boiling. Also, the Nusselt (Nu) number and the Rayleigh (Ra) number in the molten metal pool region were obtained as functions of time. Analysis was done for the relationship between the heat flux and the temperature difference between the metal layer surface and the boiling coolant. In this experiment, the heat transfer is achieved with accompanying solidification in the molten metal pool by the boiling R113 coolant there above. The present test results of the natural convection heat transfer on the molten metal pool are higher than those of the liquid metal natural convection heat transfer without coolant boiling. It can be interpreted that the heat transfer rate is enhanced by the overlying boiling coolant having the high heat removal rate. Analysis of the relationship between the heat flux and the difference between the metal layer surface temperature and the coolant bulk boiling temperature revealed that the CHF occurs when the temperature difference reaches a neighborhood of 50 Celsius degrees. Also, if the temperature

Effect of heat treatments on the tensile and electrical properties of high-strength, high-conductivity copper alloys

Energy Technology Data Exchange (ETDEWEB)

Zinkle, S.J.; Eatherly, W.S. [Oak Ridge National Lab., TN (United States)

1997-08-01

The unirradiated tensile properties of CuCrZr produced by two different vendors have been measured following different heat treatments. Room temperature electrical resistivity measurements were also performed in order to estimate the thermal conductivity of these specimens. The thermomechanical conditions studied included solution quenched, solution quenched and aged (ITER reference heat treatment), simulated slow HIP thermal cycle ({approximately}1{degrees}C/min cooling from solutionizing temperature) and simulated fast HIP thermal cycle ({approximately}100{degrees}C/min cooling from solutionizing temperature). Specimens from the last two heat treatments were tested in both the solution-cooled condition and after subsequent precipitate aging at 475{degrees}C for 2 h. Both of the simulated HIP thermal cycles caused a pronounced decreases in the strength and electrical conductivity of CuCrZr. The tensile and electrical properties were unchanged by subsequent aging in the slow HIP thermal cycles caused a pronounced decrease in the strength and electrical conductivity of CuCrZr. The tensile and electrical properties were unchanged by subsequent aging in the slow HIP thermal cycle specimens, whereas the strength and conductivity following aging in the fast HIP thermal cycle improved to {approximately}65% of the solution quenched and aged CuCrZr values. Limited tensile and electrical resistivity measurements were also made on two new heats of Hycon 3HP CuNiBe. High strength but poor uniform and total elongations were observed at 500{degrees}C on one of these new heats of CuNiBe, similar to that observed in other heats.

Effect of heat treatments on the tensile and electrical properties of high-strength, high-conductivity copper alloys

International Nuclear Information System (INIS)

Zinkle, S.J.; Eatherly, W.S.

1997-01-01

The unirradiated tensile properties of CuCrZr produced by two different vendors have been measured following different heat treatments. Room temperature electrical resistivity measurements were also performed in order to estimate the thermal conductivity of these specimens. The thermomechanical conditions studied included solution quenched, solution quenched and aged (ITER reference heat treatment), simulated slow HIP thermal cycle (∼1 degrees C/min cooling from solutionizing temperature) and simulated fast HIP thermal cycle (∼100 degrees C/min cooling from solutionizing temperature). Specimens from the last two heat treatments were tested in both the solution-cooled condition and after subsequent precipitate aging at 475 degrees C for 2 h. Both of the simulated HIP thermal cycles caused a pronounced decreases in the strength and electrical conductivity of CuCrZr. The tensile and electrical properties were unchanged by subsequent aging in the slow HIP thermal cycles caused a pronounced decrease in the strength and electrical conductivity of CuCrZr. The tensile and electrical properties were unchanged by subsequent aging in the slow HIP thermal cycle specimens, whereas the strength and conductivity following aging in the fast HIP thermal cycle improved to ∼65% of the solution quenched and aged CuCrZr values. Limited tensile and electrical resistivity measurements were also made on two new heats of Hycon 3HP CuNiBe. High strength but poor uniform and total elongations were observed at 500 degrees C on one of these new heats of CuNiBe, similar to that observed in other heats

Formulation of stable Bacillus subtilis AH18 against temperature fluctuation with highly heat-resistant endospores and micropore inorganic carriers.

Science.gov (United States)

Chung, Soohee; Lim, Hyung Mi; Kim, Sang-Dal

2007-08-01

To survive the commercial market and to achieve the desired effect of beneficial organisms, the strains in microbial products must be cost-effectively formulated to remain dormant and hence survive through high and low temperatures of the environment during transportation and storage. Dormancy and stability of Bacillus subtilis AH18 was achieved by producing endospores with enhanced heat resistance and using inorganic carriers. Heat stability assays, at 90 degrees C for 1 h, showed that spores produced under a sublethal temperature of 57 degrees C was 100 times more heat-resistant than the ones produced by food depletion at the growing temperature of 37 degrees C. When these highly heat-resistant endospores were formulated with inorganic carriers of natural and synthetic zeolite or kaolin clay minerals having substantial amount of micropores, the dormancy of the endospores was maintained for 6 months at 15-25 degrees C. Meanwhile, macroporous perlite carriers with average pore diameter larger than 3.7 microm stimulated the germination of the spores and rapid proliferation of the bacteria. These results indicated that a B. subtilis AH18 product that can remain dormant and survive through environmental temperature fluctuation can be formulated by producing heat-stressed endospores and incorporating inorganic carriers with micropores in the formulation step.

Natural convection heat transfer on two horizontal cylinders in liquid sodium

Energy Technology Data Exchange (ETDEWEB)

Hata, K.; Shiotsu, M.; Takeuchi, Y. [Institute of Atomic Energy, Kyoto Univ. (Japan)] [and others

1995-09-01

Natural convection heat transfer on two horizontal 7.6 mm diameter test cylinders assembled with the ratio of the distance between each cylinder axis to the cylinder diameter, S/D, of 2 in liquid sodium was studied experimentally and theoretically. The heat transfer coefficients on the cylinder surface due to the same heat inputs ranging from 1.0 X 10{sup 7} to 1.0 x 10{sup 9} W/m{sup 3} were obtained experimentally for various setting angeles, {gamma}, between vertical direction and the plane including both of these cylinder axis over the range of zero to 90{degrees}. Theoretical equations for laminar natural convection heat transfer from the two horizontal cylinders were numerically solved for the same conditions as the experimental ones considering the temperature dependence of thermophysical properties concerned. The average Nusselt numbers, Nu, values on the Nu versus modified Rayleigh number, R{sub f}, graph. The experimental values of Nu for the upper cylinder are about 20% lower than those for the lower cylinder at {gamma} = 0{degrees} for the range of R{sub f} tested here. The value of Nu for the upper cylinder becomes higher and approaches that for the lower cylinder with the increase in {gamma} over range of 0 to 90{degrees}. The values of Nu for the lower cylinder at each {gamma} are almost in agreement with those for a single cylinder. The theoretical values of Nu on two cylinders except those for R{sub f}<4 at {gamma} = 0{degrees} are in agreement with the experimental data at each {gamma} with the deviations less than 15%. Correlations for Nu on the upper and lower cylinders were obtained as functions of S/D and {gamma} based n the theoretical solutions for the S/D ranged over 1.5 to 4.0.

Inactivation of 12 viruses by heating steps applied during manufacture of a hepatitis B vaccine

NARCIS (Netherlands)

Lelie, P. N.; Reesink, H. W.; Lucas, C. J.

1987-01-01

The efficacy of two heating cycles (90 sec at 103 degrees C and 10 hr at 65 degrees C) used during manufacture of a plasma-derived hepatitis-B vaccine was validated for the inactivation of 12 virus families. A period of 15 min warming up to 65 degrees C had already completely inactivated

Experimental Study of Flow Boiling Heat Transfer in a Horizontal Microfin Tube

OpenAIRE

Yu, Jian; Koyama, Shigeru; Momoki, Satoru

1995-01-01

An experimental study on flow boiling heat transfer in a horizontal microfin tube is conducted with pure refrigerants HFC134a, HCFC123 and HCFC22 using a water-heated double-tube type test section. The test microfin tube is a copper tube having the following dimensions: 8.37mm mean inside diameter, 0.168mm fin height, 60fin number and 18 degree of helix angle. The local heat transfer coefficients for both counter and parallel flows are measured in a range of heat flux of 1 to 93W/m^2, mass ve...

Second-degree discrete Painleve equations conceal first-degree ones

International Nuclear Information System (INIS)

Ramani, A; Grammaticos, B; Joshi, N

2010-01-01

We examine various second-degree difference equations which have been proposed over the years and according to their authors' claims should be integrable. This study is motivated by the fact that we consider that second-degree discrete systems cannot be integrable due to the proliferation of the images (and pre-images) of the initial point. We show that in the present cases no contradiction exists. In all cases examined, we show that there exists an underlying integrable first-degree mapping which allows us to obtain an appropriate solution of the second-degree one.

Social media responses to heat waves

Science.gov (United States)

Jung, Jihoon; Uejio, Christopher K.

2017-07-01

Social network services (SNSs) may benefit public health by augmenting surveillance and distributing information to the public. In this study, we collected Twitter data focusing on six different heat-related themes (air conditioning, cooling center, dehydration, electrical outage, energy assistance, and heat) for 182 days from May 7 to November 3, 2014. First, exploratory linear regression associated outdoor heat exposure to the theme-specific tweet counts for five study cities (Los Angeles, New York, Chicago, Houston, and Atlanta). Next, autoregressive integrated moving average (ARIMA) time series models formally associated heat exposure to the combined count of heat and air conditioning tweets while controlling for temporal autocorrelation. Finally, we examined the spatial and temporal distribution of energy assistance and cooling center tweets. The result indicates that the number of tweets in most themes exhibited a significant positive relationship with maximum temperature. The ARIMA model results suggest that each city shows a slightly different relationship between heat exposure and the tweet count. A one-degree change in the temperature correspondingly increased the Box-Cox transformed tweets by 0.09 for Atlanta, 0.07 for Los Angeles, and 0.01 for New York City. The energy assistance and cooling center theme tweets suggest that only a few municipalities used Twitter for public service announcements. The timing of the energy assistance tweets suggests that most jurisdictions provide heating instead of cooling energy assistance.

Plasma treatment of heat-resistant materials

International Nuclear Information System (INIS)

Vlasov, V A; Kosmachev, P V; Skripnikova, N K; Bezukhov, K A

2015-01-01

Refractory lining of thermal generating units is exposed to chemical, thermal, and mechanical attacks. The degree of fracture of heat-resistant materials depends on the chemical medium composition, the process temperature and the material porosity. As is known, a shortterm exposure of the surface to low-temperature plasma (LTP) makes possible to create specific coatings that can improve the properties of workpieces. The aim of this work is to produce the protective coating on heat-resistant chamotte products using the LTP technique. Experiments have shown that plasma treatment of chamotte products modifies the surface, and a glass-ceramic coating enriched in mullite is formed providing the improvement of heat resistance. For increasing heat resistance of chamotte refractories, pastes comprising mixtures of Bacor, alumina oxide, and chamot were applied to their surfaces in different ratios. It is proved that the appropriate coating cannot be created if only one of heat-resistant components is used. The required coatings that can be used and recommended for practical applications are obtained only with the introduction of powder chamot. The paste composition of 50% chamot, 25% Bacor, and 25% alumina oxide exposed to plasma treatment, has demonstrated the most uniform surface fusion. (paper)

Microbial safety control of compost material with cow dung by heat treatment.

Science.gov (United States)

Gong, Chun-ming

2007-01-01

Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was put into a heat treatment machine in pilot plan, and harmless condition in short time was examined. The results indicated, pathogenic indicator bacteria such as coliform bacteria, fecal coliform, Escherichia coli and salmonella were all 106 cfu/g dw at the beginning, died rapidly when cow dung temperature rose to above 50 degrees C, and not detected at 54-68 degrees C for 6-24 h heat treatment. Coliform bacteria and salmonella in heated cow dung were not detected by re-growth culture and enrichment culture examination. Moreover, it was hardly influenced on the fermentation ability of composting microbe, organic decomposition bacteria. During heat treatment, the mesophile decreased rapidly and the thermophile stabilized or increased, and the most of composting microbe were bacillus in cow dung by fluorescence microscope, this indicated that bacillus was dominator and composting microbe in composting process.

Effect of the Dispersibility of Nano-CuO Catalyst on Heat Releasing of AP/HTPB Propellant

International Nuclear Information System (INIS)

Yang, Y.; Yu, X.; Wang, J.; Wang, Y.

2011-01-01

Kneading time is adjusted to change the dispersibility of nano-CuO in AP/HTPB (Ammonia Perchlorate/Hydroxyl-Terminated Polybutadiene) composite propellants. Nano-CuO/AP is prepared to serve as the other dispersing method of nano-CuO, named pre dispersing procedure. Several kinds of heat releasing, thermal decomposition by DSC, combustion heat in oxygen environment, and explosion heat in nitrogen environment, are characterized to learn the effect of dispersibility of nano-CuO catalyst on heat releasing of propellants. With pre-dispersing procedures, thermal decomposition temperature of nano-CuO/AP and its propellant are about 25 degree C and 8.6 degree C lower than that of AP simple mixed with nano-CuO and its propellant, respectively. Comparing propellant with simple mixed nano-CuO kneading 3 hours, combustion heat and explosion heat of propellant with nano-CuO/AP increase about 1.4% and 1.7%, respectively. However, because of the breaking of nano-CuO/AP structure during kneading procedure, combustion heat and explosion heat of all the samples are decreased with the increase of kneading time after 3 hours.

Effect of various pre-treatments on the ultrafiltration of sweet cheese whey at about 55 degrees C

Energy Technology Data Exchange (ETDEWEB)

Hiddink, J; De Boer, R; Nooy, P F.C.

1981-11-01

The permeate flux at 55 degrees C during ultrafiltration of Gouda cheese whey (5.5% TS and 11% TS) can be readily manipulated by applying pre-treatments based on inactivation or removal of calcium. The following pre-treatments were carried out: clarification, decalcificication, desalting, pre-heating at 45, 55, and 60 degrees C for 30 minutes, pre-heating at 55 degrees C for 30 minutes combined with pH adjustment to pH 7.5, 4.5 and 3.0 and preheating at 55 degrees C for 30 minutes (coupled with addition of sodum hexametaphosphate. In particular decalification, clarification and pH adjustment to 7.5 or 3.0 gave high permeate fluxes, while pre- heating for 30 minutes resulted in a moderate flux. The pretreatment not only affects the permeate flux but also the composition and properties of the whey protein concentrate. A high ash content, which also reflects a high calcium and phosphorous content, was obtained with a pretreatment based on pH 7 5, while low ash contents were achieved by desalting and clarification. The solubility of the protein was reduced to some 60-70% if the pH of the pre-treated whey was brought to 3.0 or 7.5. Furthermore, it appeared that the influence of the type of membrane - a tubular and a plate-and-frame module were used - was of minor importance as far as the retention or the composition of the whey protein concentrate was concerned. However, the permeate flux of the two types of equipment was different. Under the applied process conditions the tubular system tended to give a higher permeate flux than did the plate-and-frame system, but the energy consumption of the former was considerably higher. (Refs. 25).

Heat Transfer and Pressure Drop with Rough Surfaces, a Literature Survey

Energy Technology Data Exchange (ETDEWEB)

Bhattacharyya, A

1964-05-15

This literature survey deals with changes in heat transfer coefficient and friction factor with varying nature and degree of roughness. Experimental data cover mainly the turbulent flow region for both air and water as flow mediums. Semiempirical analysis about changes in heat transfer coefficient due to roughness has been included. An example of how to use these data to design a heat exchanger surface is also cited. The extreme case of large fins has not been considered. Available literature between 1933 - 1963 has been covered.

Effect of heat treatment upon the fatigue-crack growth behavior of Alloy 718 weldments

International Nuclear Information System (INIS)

Mills, W.J.; James, L.A.

1981-05-01

The microstructural features that influenced the room and elevated temperature fatigue-crack growth behavior of as-welded, conventional heat-treated, and modified heat-treated Alloy 718 GTA weldments were studied. Electron fractographic examination of fatigue fracture surfaces revealed that operative fatigue mechanisms were dependent on microstructure, temperatures and stress intensity factor. All specimens exhibited three basic fracture surface appearances at temperatures up to 538 degrees C: crystallographic faceting at low stress intensity range (ΔK) levels, striation, formation at intermediate values, and dimples coupled with striations in the highest (ΔK) regime. At 649 degrees C, the heat-treated welds exhibited extensive intergranular cracking. Laves and δ particles in the conventional heat-treated material nucleated microvoids ahead of the advancing crack front and caused on overall acceleration in crack growth rates at intermediate and high ΔK levels. The modified heat treatment removed many of these particles from the weld zone, thereby improving its fatigue resistance. The dramatically improved fatigue properties exhibited by the as-welded material was attributed to compressive residual stresses introduced by the welding process. 19 refs., 16 figs

Development of a High-Performance Fin-and-Tube Heat Exchanger with Vortex Generators for a Vending Machine

Science.gov (United States)

Iwasaki, Masamichi; Saito, Hiroshi; Mochizuki, Sadanari; Murata, Akira

The effect of delta-wing-vortex generators (combination of a delta wing and a delta winglet pair) on the heat transfer performance of fin-and-tube heat exchangers for vending machines has been investegated. Flow visualizations, numerical simulations and heat transfer experiments were conducted to find an optimum geometrical shape and arrangement of the vortex generators. Maximum heat transfer enhancement was achieved by the combination of (a) the delta wing with the apex angle of 86 degrees and (b) the delta winglet pair with the inline angle of 45 degrees. In relatively low Reynolds number range, about 40 % increase in heat transfer coefficient was attained with the above mentioned combination of the vortex generators compared to the ordinary heat exchangers with plain fins. It was revealed that the heat transfer enhancement was attributed to (1) the longitudinal vortexes generated by the delta wing and (2) the reduction of wake area behind the tube. It was also found that an increase in the apex angle of the delta wing brought about heat transfer enhancement, and the scale as well as the streggth of the induced longitudinal vortices played an important role in the heat transfer performance.

Heat Diffusion in Gases, Including Effects of Chemical Reaction

Science.gov (United States)

Hansen, C. Frederick

1960-01-01

The diffusion of heat through gases is treated where the coefficients of thermal conductivity and diffusivity are functions of temperature. The diffusivity is taken proportional to the integral of thermal conductivity, where the gas is ideal, and is considered constant over the temperature interval in which a chemical reaction occurs. The heat diffusion equation is then solved numerically for a semi-infinite gas medium with constant initial and boundary conditions. These solutions are in a dimensionless form applicable to gases in general, and they are used, along with measured shock velocity and heat flux through a shock reflecting surface, to evaluate the integral of thermal conductivity for air up to 5000 degrees Kelvin. This integral has the properties of a heat flux potential and replaces temperature as the dependent variable for problems of heat diffusion in media with variable coefficients. Examples are given in which the heat flux at the stagnation region of blunt hypersonic bodies is expressed in terms of this potential.

Heat-transfer distributions on biconics at incidence in hypersonic-hypervelocity He, N2, air, and CO2 flows

Science.gov (United States)

Miller, C. G.; Micol, J. R.; Gnoffo, P. A.; Wilder, S.E.

1983-01-01

Laminar heat-transfer rates were measured on spherically blunted, 13 degrees/F degrees on-axis and bent biconics (fore cone bent 7 degrees upward relative to aft cone) at hypersonic-hypervelocity flow conditions in the Langley Expansion Tube. Freestream velocities from 4.5 to 6.9 km/sec and Mach numbers from 6 to 9 were generated using helium, nitrogen, air, and carbon dioxide test gases, resulting in normal shock density ratios from 4 to 19. Angle of attack, referenced to the axis of the aft cone, was varied from zero to 20 degrees in 4 degree increments. The effect of nose bend, angle of attack, and real-gas phenomena on heating distributions are presented along with comparisons of measurement to prediction from a code which solves the three-dimensional 'parabolized Navier-Stokes' equations.

Protein denaturation and functional properties of Lenient Steam Injection heat treated whey protein concentrate

DEFF Research Database (Denmark)

Dickow, Jonatan Ahrens; Kaufmann, Niels; Wiking, Lars

2012-01-01

Whey protein concentrate (WPC) was heat treated by use of the novel heat treatment method of Lenient Steam Injection (LSI) to elucidate new functional properties in relation to heat-induced gelation of heat treated WPC. Denaturation was measured by both DSC and FPLC, and the results of the two...... methods were highly correlated. Temperatures of up to 90 °C were applicable using LSI, whereas only 68 °C could be reached by plate heat exchange before coagulation/fouling. Denaturation of whey proteins increased with increasing heat treatment temperature up to a degree of 30–35% denaturation at 90 °C...

Fate of TCE in heated Fort Lewis soil.

Science.gov (United States)

Costanza, Jed; Fletcher, Kelly E; Löffler, Frank E; Pennell, Kurt D

2009-02-01

This study explores the transformation of trichloroethene (TCE) caused by heating contaminated soil and groundwater samples obtained from the East Gate Disposal Yard (EGDY) located in Fort Lewis, WA. After field samples transferring into glass ampules and introducing 1.5 micromol of TCE, the sealed ampules were incubated at temperatures of 25, 50, and 95 degrees C for periods of up to 95.5 days. Although TCE was completely transformed into cis-1,2-dichloroethene (cis-DCE) after 42 days at 25 degrees C by microbial activity, this transformation was not observed at 50 or 95 degrees C. Chloride levels increased after 42 days at 25 degrees C corresponding to the mass of TCE transformed to cis-DCE, were constant at 50 degrees C, and increased at 95 degrees C yielding a TCE degradation half-life of 1.6-1.9 years. These findings indicate that indigenous microbes contribute to the partial dechlorination of TCE to cis-DCE at temperatures of less than 50 degrees C, whereas interphase mass transfer and physical recovery of TCE will predominate over in situ degradation processes at temperatures of greater than 50 degrees C during thermal treatment at the EGDY site.

Corrosion of heat exchanger materials under heat transfer conditions

International Nuclear Information System (INIS)

Tapping, R.L.; Lavoie, P.A.; Disney, D.J.

1987-01-01

Severe pitting has occurred in moderator heat exchangers tubed with Incoloy-800 in Pickering Nuclear Generating Station. The pitting originated on the cooling side (outside) of the tubes and perforation occurred in less than two years. It was known from corrosion testing at CRNL that Incoloy-800 was not susceptible to pitting in Lake Ontario water under isothermal conditions. Corrosion testing with heat transfer across the tube wall was carried out, and it was noted that severe pitting could occur under deposits formed on the tubes in silty Lake Ontario water. Subsequent testing, carried out in co-operation with Ontario Hydro Research Division, investigated the pitting resistance of other candidate tubing alloys: Incoloy-825, 904 L stainless steel, AL-6X, Inconel-625, 70:30 Cu:Ni, titanium, Sanicro-30 and Sanicro-28 1 . Of these, only titanium and Sanicro-28 have not suffered some degree of pitting attack in silt-containing Lake Ontario Water. In the absence of silt, and hence deposits, no pitting took place on any of the alloys tested

Fuzzy multivariable control of domestic heat pumps

International Nuclear Information System (INIS)

Underwood, C.P.

2015-01-01

Poor control has been identified as one of the reasons why recent field trials of domestic heat pumps in the UK have produced disappointing results. Most of the technology in use today uses a thermostatically-controlled fixed speed compressor with a mechanical expansion device. This article investigates improved control of these heat pumps through the design and evaluation of a new multivariable fuzzy logic control system utilising a variable speed compressor drive with capacity control linked through to evaporator superheat control. A new dynamic thermal model of a domestic heat pump validated using experimental data forms the basis of the work. The proposed control system is evaluated using median and extreme daily heating demand profiles for a typical UK house compared with a basic thermostatically-controlled alternative. Results show good tracking of the heating temperature and superheat control variables, reduced cycling and an improvement in performance averaging 20%. - Highlights: • A new dynamic model of a domestic heat pump is developed and validated. • A new multivariable fuzzy logic heat pump control system is developed/reported. • The fuzzy controller regulates both plant capacity and evaporator superheat degree. • Thermal buffer storage is also considered as well as compressor cycling. • The new controller shows good variable tracking and a reduction in energy of 20%.

Mapping temperature-induced conformational changes in the Escherichia coli heat shock transcription factor sigma 32 by amide hydrogen exchange

DEFF Research Database (Denmark)

Rist, Wolfgang; Jørgensen, Thomas J D; Roepstorff, Peter

2003-01-01

Stress conditions such as heat shock alter the transcriptional profile in all organisms. In Escherichia coli the heat shock transcription factor, sigma 32, out-competes upon temperature up-shift the housekeeping sigma-factor, sigma 70, for binding to core RNA polymerase and initiates heat shock...... gene transcription. To investigate possible heat-induced conformational changes in sigma 32 we performed amide hydrogen (H/D) exchange experiments under optimal growth and heat shock conditions combined with mass spectrometry. We found a rapid exchange of around 220 of the 294 amide hydrogens at 37...... degrees C, indicating that sigma 32 adopts a highly flexible structure. At 42 degrees C we observed a slow correlated exchange of 30 additional amide hydrogens and localized it to a helix-loop-helix motif within domain sigma 2 that is responsible for the recognition of the -10 region in heat shock...

Secondary hyperalgesia to heat stimuli after burn injury in man

DEFF Research Database (Denmark)

Pedersen, J L; Kehlet, H

1998-01-01

The aim of the study was to examine the presence of hyperalgesia to heat stimuli within the zone of secondary hyperalgesia to punctate mechanical stimuli. A burn was produced on the medial part of the non-dominant crus in 15 healthy volunteers with a 50 x 25 mm thermode (47 degrees C, 7 min......), and assessments were made 70 min and 40 min before, and 0, 1, and 2 h after the burn injury. Hyperalgesia to mechanical and heat stimuli were examined by von Frey hairs and contact thermodes (3.75 and 12.5 cm2), and pain responses were rated with a visual analog scale (0-100). The area of secondary hyperalgesia...... to punctate stimuli was assessed with a rigid von Frey hair (462 mN). The heat pain responses to 45 degrees C in 5 s (3.75 cm2) were tested in the area just outside the burn, where the subjects developed secondary hyperalgesia, and on the lateral crus where no subject developed secondary hyperalgesia (control...

Development of an easy-debonding orthodontic adhesive using thermal heating.

Science.gov (United States)

Tsuruoka, Takashi; Namura, Yasuhiro; Shimizu, Noriyoshi

2007-01-01

We produced experimentally a new bonding material that consisted of a mixture of a base resin (4-META/MMA-TBB resin adhesive) and thermoexpandable microcapsules for safe, easy debonding. Microcapsules in the base resin would start expansion at 80 degrees C, leading to a remarkable decrease in bond strength. Stainless steel brackets were bonded to bovine permanent mandibular incisors using bonding materials containing the microcapsules at different contents. After thermal cycling or heating, the shear bond strength of the brackets was measured. Shear bond strength of the bonding materials containing 30-40 wt% microcapsules decreased to about one-third or one-fifth that of the base resin on heating. Heating the brackets for eight seconds increased the temperature in the pulp chamber by 2 degrees C, which should not induce pulp damage. Results obtained suggested that the new bonding material should prove useful for removing brackets easily at the time of bracket debonding without any pain or enamel cracks, while maintaining the bonding strength during active orthodontic treatment.

Heat Capacity Analysis Report

International Nuclear Information System (INIS)

Findikakis, A.

2004-01-01

The purpose of this report is to provide heat capacity values for the host and surrounding rock layers for the waste repository at Yucca Mountain. The heat capacity representations provided by this analysis are used in unsaturated zone (UZ) flow, transport, and coupled processes numerical modeling activities, and in thermal analyses as part of the design of the repository to support the license application. Among the reports that use the heat capacity values estimated in this report are the ''Multiscale Thermohydrologic Model'' report, the ''Drift Degradation Analysis'' report, the ''Ventilation Model and Analysis Report, the Igneous Intrusion Impacts on Waste Packages and Waste Forms'' report, the ''Dike/Drift Interactions report, the Drift-Scale Coupled Processes (DST and TH Seepage) Models'' report, and the ''In-Drift Natural Convection and Condensation'' report. The specific objective of this study is to determine the rock-grain and rock-mass heat capacities for the geologic stratigraphy identified in the ''Mineralogic Model (MM3.0) Report'' (BSC 2004 [DIRS 170031], Table 1-1). This report provides estimates of the heat capacity for all stratigraphic layers except the Paleozoic, for which the mineralogic abundance data required to estimate the heat capacity are not available. The temperature range of interest in this analysis is 25 C to 325 C. This interval is broken into three separate temperature sub-intervals: 25 C to 95 C, 95 C to 114 C, and 114 C to 325 C, which correspond to the preboiling, trans-boiling, and postboiling regimes. Heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of material by one degree (Nimick and Connolly 1991 [DIRS 100690], p. 5). The rock-grain heat capacity is defined as the heat capacity of the rock solids (minerals), and does not include the effect of water that exists in the rock pores. By comparison, the rock-mass heat capacity considers the heat capacity of both solids and pore

Better Brakes

Science.gov (United States)

1976-01-01

Through continuing studies on high-temperature space materials useful for better brake linings, Bendix Corporation worked with Ames Research Center to develop a novel composite. This team worked to fabricate several combinations of composite materials and evaluated results. The one selected increases wear rates and lowers costs. It exhibits constant coefficient of friction at temperatures as high as 650 degrees Fahrenheit, a region where conventional brake linings fade markedly. Other suitable markets include brakes for trucks and industrial equipment such as overhead cranes and hoists. Afterwards brake linings could find successful application in passenger cars.

Inactivation of Escherichia coli in a tropical fruit smoothie by a combination of heat and pulsed electric fields.

Science.gov (United States)

Walkling-Ribeiro, M; Noci, F; Cronin, D A; Lyng, J G; Morgan, D J

2008-10-01

Moderate heat in combination with pulsed electric fields (PEF) was investigated as a potential alternative to thermal pasteurization of a tropical fruit smoothie based on pineapple, banana, and coconut milk, inoculated with Escherichia coli K12. The smoothie was heated from 25 degrees C to either 45 or 55 degrees C over 60 s and subsequently cooled to 10 degrees C. PEF was applied at electric field strengths of 24 and 34 kV/cm with specific energy inputs of 350, 500, and 650 kJ/L. Both processing technologies were combined using heat (45 or 55 degrees C) and the most effective set of PEF conditions. Bacterial inactivation was estimated on standard and NaCl-supplemented tryptone soy agar (TSA) to enumerate sublethally injured cells. By increasing the temperature from 45 to 55 degrees C, a higher reduction in E. coli numbers (1 compared with 1.7 log(10) colony forming units {CFU} per milliliter, P field strength was increased during stand-alone PEF treatment from 24 to 34 kV/cm, a greater number of E. coli cells were inactivated (2.8 compared with 4.2 log(10) CFU/mL, P or = 0.05) achieved by thermal pasteurization (72 degrees C, 15 s). A reversed hurdle processing sequence did not affect bacterial inactivation (P> or = 0.05). No differences were observed (P> or = 0.05) between the bacterial counts estimated on nonselective and selective TSA, suggesting that sublethal cell injury did not occur during single PEF treatments or combined heat/PEF treatments.

Heat transfer characteristics in a channel fitted with zigzag-cut baffles

Energy Technology Data Exchange (ETDEWEB)

Nuntadusit, Chayut; Waehayee, Makatar [Prince of Songkla University, Hat Yai (Thailand); Piya, Ibroheng [Princess of Naradhiwas University, Naradhiwas (Thailand); Eiamsa-ard, Smith [Mahanakorn University of Technology, Bangkok (Thailand)

2015-06-15

The heat transfer characteristics were experimentally investigated in a wind channel with different types of cut baffles for heat transfer augmentation. The aim of using zigzag-cut baffles is to create 3D flow structure behind the baffles instead of transverse vortex flow leading to enhance heat transfer. In this study, 4 types of baffles were examined; conventional baffle (Rectangular cross section with no cut), baffle with rectangular zigzag-cut, baffle with triangle zigzag-cut at 45 degree and at 90 degree. All of the baffles have the same height at H = 15 mm and flow blocking area. In the experiment, the row of seven baffles was attached on the inner surface of wind channel. The effects of pitch spacing length were also investigated at baffle pitch distance P/H = 4, 6 and 8 (H: Height of baffle). The experiments were performed at constant Reynolds number (Re) of 20000. The heat transfer patterns via Thermochromic liquid crystal sheet were visualized and recorded with a digital camera. The recorded images were then analyzed with image processing technique to obtain the distribution of Nusselt number. The flow characteristics pass through the baffles were also numerically studied with CFD simulation for understanding the heat transfer characteristics. The friction losses were measured to evaluate the thermal performance for each baffle. It was found that the baffle with rectangular zigzag-cut gives the best thermal performance due to heat transfer augmentation in upstream and downstream side of baffle.

Hydronic Heating Retrofits for Low-Rise Multifamily Buildings: Boiler Control Replacement and Monitoring

Energy Technology Data Exchange (ETDEWEB)

Dentz, J.; Henderson, H.; Varshney, K.

2014-09-01

The ARIES Collaborative, a U.S. Department of Energy Building America research team, partnered with NeighborWorks America affiliate Homeowners' Rehab Inc. (HRI) of Cambridge, Massachusetts, to study improvements to the central hydronic heating system in one of the nonprofit's housing developments. The heating controls in the three-building, 42-unit Columbia Cambridge Alliance for Spanish Tenants housing development were upgraded. Fuel use in the development was excessive compared to similar properties. A poorly insulated thermal envelope contributed to high energy bills, but adding wall insulation was not cost-effective or practical. The more cost-effective option was improving heating system efficiency. Efficient operation of the heating system faced several obstacles, including inflexible boiler controls and failed thermostatic radiator valves. Boiler controls were replaced with systems that offer temperature setbacks and one that controls heat based on apartment temperature in addition to outdoor temperature. Utility bill analysis shows that post-retrofit weather-normalized heating energy use was reduced by 10%-31% (average of 19%). Indoor temperature cutoff reduced boiler runtime (and therefore heating fuel consumption) by 28% in the one building in which it was implemented. Nearly all savings were obtained during night which had a lower indoor temperature cut off (68 degrees F) than day (73 degrees F). This implies that the outdoor reset curve was appropriately adjusted for this building for daytime operation. Nighttime setback of heating system supply water temperature had no discernable impact on boiler runtime or gas bills.

Physiological responses of horses to a treadmill simulated speed and endurance test in high heat and humidity before and after humid heat acclimation.

Science.gov (United States)

Marlin, D J; Scott, C M; Schroter, R C; Harris, R C; Harris, P A; Roberts, C A; Mills, P C

1999-01-01

To investigate whether horses were able to acclimate to conditions of high temperature and humidity, 5 horses of different breeds were trained for 80 min on 15 consecutive days on a treadmill at 30 degrees C and 80%RH. Training consisted of a combination of long duration low-intensity exercise, medium duration medium intensity exercise and short duration high intensity exercise. Between training sessions the horses were maintained at 11+/-3 degrees C and 74+/-2%RH. Before (PRE-ACC) and after acclimation (POST-ACC) the horses undertook a simulated Competition Exercise Test (CET), designed to represent the Speed and Endurance Test of a 3-day event, at 30 degrees C/80%RH. Maximal oxygen uptake (VO2PEAK) was not changed following acclimation (PRE-ACC 141+/-8 ml/min/kg bwt vs. POST-ACC 145+/-9 ml/min/kg bwt [STPD], P>0.05). Following acclimation, 4 of the 5 horses were able to complete a significantly greater amount of Phase D in the CET (PRE-ACC 6.3+/-0.3 min vs. POST-ACC 7.3+/-0.3 min, P<0.05; target time = 8 min). Resting body temperatures (pulmonary artery [TPA], rectal [TREC] and tail-skin [TTSK] temperatures) were all significantly lower following acclimation. During exercise, metabolic heat production (M) and heat dissipation (HD), for the same exercise duration, were both significantly lower following acclimation (P<0.05), although heat storage (HS) was significantly higher (P<0.05). The higher heat storage following acclimation was associated with a lower TTSK for a given TPA and a decreased total fluid loss (% bodyweight, P<0.05). Plasma volume was not changed following acclimation. The relationship of sweating rate (SR) to TPA or TTSK on either the neck or the gluteal region was not significantly altered by acclimation, although the onset of sweating occurred at a lower TPA or TTSK following acclimation (P<0.05). The horses in the present study showed a number of physiological adaptations to a period of 15 days of exposure to high heat and humidity consistent

Reflux and Belching After 270 Degree Versus 360 Degree Laparoscopic Posterior Fundoplication

NARCIS (Netherlands)

Broeders, Joris A.; Bredenoord, Albert J.; Hazebroek, Eric J.; Broeders, Ivo A.; Gooszen, Hein G.; Smout, André J.

2012-01-01

Objective: To investigate differences in effects of 270 degrees (270 degrees LPF) and 360 degrees laparoscopic posterior fundoplication (360 degrees LPF) on reflux characteristics and belching. Background: Three hundred sixty degrees LPF greatly reduces the ability of the stomach to vent ingested

Shivering and rewarming after cardiac surgery: comparison of ventilator circuits with humidifier and heated wires to heat and moisture exchangers.

Science.gov (United States)

McEvoy, M T; Carey, T J

1995-07-01

Detrimental physiologic effects of shivering in the cardiac surgery patient have been well documented. Rewarming techniques have been compared, with noted differences in the incidence of shivering. Ventilator circuits have not been examined independently from other rewarming variables. To compare heated wire humidification circuits with heat and moisture exchanger circuits on the incidence of shivering and speed and pattern of rewarming in mechanically ventilated patients. A prospective, descriptive, correlational study was done on 140 adult cardiac surgery patients in a university teaching medical center. All subjects underwent cardiac surgical procedures with hypothermic cardiopulmonary bypass. Subjects were randomized to humidified, heated wire circuits (n = 70) or heat and moisture exchanger circuits (n = 70). Heated water blankets were used on all patients. Mean intensive care unit admission temperature was 35.28 degrees C. No statistical differences were found in preoperative, demographic, or operative course data between treatment and control groups. Shivering was more common in the heat and moisture exchanger group than in the heated wire group. In our analysis, the only variable associated with shivering was the type of ventilator circuit. Patients using heated wire systems rewarmed more rapidly and had significantly higher temperatures than did patients using heat and moisture exchangers. These data suggest that use of heated wire humidified ventilator circuits with heated water blankets in adult cardiac surgery patients significantly reduces the incidence of shivering and results in a more rapid return to normothermia.

Short communication. Effect of soybean meal heat procedures on growth performance of broiler chickens

Energy Technology Data Exchange (ETDEWEB)

Tousi-Mojarradi, M.; Seidavi, A.; Dadashbeiki, M.; Roca-Fernandez, A. I.

2014-06-01

The aim of this research was to study the effect of soybean meal (SBM) heat procedures on growth performance of broiler chickens. A trial was carried out using 200 male Ross 308 strain chickens during 3 feeding periods (starter, grower and finisher, 42 days). The experiment was based on a completely randomized design with 5 treatments giving 4 replications of 10 broilers per treatment. Treatments consisted on: T1 (control, un-processed SBM), T2 (autoclaved SBM: 121 degree centigrade, 20 min), T3 (autoclaved SBM: 121 degree centigrade, 30 min), T4 (roasted SBM: 120 degree centigrade, 20 min) and T5 (microwaved SBM: 46 degree centigrade, 540 watt, 7 min). Growth performance of animals was examined by determining body weight (BW), body weight grain (BWG), feed intake (FI) and feed conversion rate (FCR). Higher BW (p<0.05) and BWG (p<0.05) and lower FCR (p<0.05) were found in broiler chickens fed heat processed SBM diets compared to those fed a raw SBM diet, probably due to higher nutrient availability. However, no differences were found among heat SBM procedures (autoclaving, roasting and microwaving) on growth performance of animals for the starter, grower and finisher periods. From the results of this experiment, it is concluded that further research needs to be developed to establish the effect of temperature-time heat procedures on nutritive value of SBM in terms of levels of anti-nutritional factors (trypsin inhibitor activity and phytic acid) and amino acids profile and its influence on growth performance of broilers. (Author)

Tank Insulation

Science.gov (United States)

1979-01-01

For NASA's Apollo program, McDonnell Douglas Astronautics Company, Huntington Beach, California, developed and built the S-IVB, uppermost stage of the three-stage Saturn V moonbooster. An important part of the development task was fabrication of a tank to contain liquid hydrogen fuel for the stage's rocket engine. The liquid hydrogen had to be contained at the supercold temperature of 423 degrees below zero Fahrenheit. The tank had to be perfectly insulated to keep engine or solar heat from reaching the fuel; if the hydrogen were permitted to warm up, it would have boiled off, or converted to gaseous form, reducing the amount of fuel available to the engine. McDonnell Douglas' answer was a supereffective insulation called 3D, which consisted of a one-inch thickness of polyurethane foam reinforced in three dimensions with fiberglass threads. Over a 13-year development and construction period, the company built 30 tanks and never experienced a failure. Now, after years of additional development, an advanced version of 3D is finding application as part of a containment system for transporting Liquefied Natural Gas (LNG) by ship.

Copper alloys for high heat flux structure applications

International Nuclear Information System (INIS)

Zinkle, S.J.; Fabritsiev, S.A.

1994-01-01

The mechanical and physical properties of copper alloys are reviewed and compared with the requirements for high heat flux structural applications in fusion reactors. High heat flux structural materials must possess a combination of high thermal conductivity and high mechanical strength. The three most promising copper alloys at the present time are oxide dispersion-strengthened copper (Cu-Al 2 O 3 ) and two precipitation-hardened copper alloys (Cu-Cr-Zr and Cu-Ni-Be). These three alloys are capable of room temperature yield strengths >400 MPa and thermal conductivities up to 350 W/m-K. All of these alloys require extensive cold working to achieve their optimum strength. Precipitation-hardened copper alloys such Cu-Cr-Zr are susceptible to softening due to precipitate overaging and recrystallization during brazing, whereas the dislocation structure in Cu-Al 2 O 3 remains stabilized during typical high temperature brazing cycles. All three alloys exhibit good resistance to irradiation-induced softening and void swelling at temperatures below 300 degrees C. The precipitation-strengthened allows typically soften during neutron irradiation at temperatures above about 300 degrees C and therefore should only be considered for applications operating at temperatures 2 O 3 ) is considered to be the best candidate for high heat flux structural applications

The influence of heated or cooled seats on the acceptable ambient temperature range

DEFF Research Database (Denmark)

Zhang, Y.F.; Wyon, David Peter; Fang, Lei

2007-01-01

series, subjects were preconditioned to be too hot, while in other series they were preconditioned to be thermally neutral. They reported their thermal sensations, overall thermal acceptability and comfort on visual analogue scales at regular intervals. Instantaneous heat flow to the seat was measured...... continuously. At each ambient room temperature, the percentage dissatisfied was found to be a second-order polynomial function of local heat flow. Zero heat flow was preferred at an air temperature of 22 degrees C and the heat flow that minimized the percentage dissatisfied was found to be a single linear...

Effect of heat stress on the pattern of protein synthesis in wheat endosperm

International Nuclear Information System (INIS)

Inwood, W.; Bernardin, J.

1990-01-01

The exposure of detached wheat heads (T. aestivum L. cv Cheyenne) to elevated temperatures resulted not only in the induction of a typical set of high and low molecular weight heat shock proteins (hsps), but also in a differential effect on the synthesis of wheat storage proteins in endosperm tissue when monitored by SDS PAGE of 35 S-labeled polypeptides. The synthesis of hsps in the endosperm had a rapid onset, reached a maximum rate within the first 2 hours at 40 degree C, and then steadily decreased during the next four hours. When heads were returned to 25 degree C after 3 hours at 40 degree C, hsp synthesis did not cease abruptly, but gradually declined over the next several hours. High molecular weight glutenin protein synthesis was drastically reduced with the same time course as heat shock protein synthesis was induced at 40 degree C. Conversely, the synthesis of gliadin proteins remained at a high level at 40 degree C. The synthesis rates for glutenin and gliadin proteins remained at low and high levels, respectively, for as long as the elevated temperature was maintained up to 7 hours

Physiological and subjective responses in the elderly when using floor heating and air conditioning systems.

Science.gov (United States)

Hashiguchi, Nobuko; Tochihara, Yutaka; Ohnaka, Tadakatsu; Tsuchida, Chiaki; Otsuki, Tamio

2004-11-01

The purpose of this study was to investigate the effects of a floor heating and air conditioning system on thermal responses of the elderly. Eight elderly men and eight university students sat for 90 minutes in a chair under the following 3 conditions: air conditioning system (A), floor heating system (F) and no heating system (C). The air temperature of sitting head height for condition A was 25 degrees C, and the maximum difference in vertical air temperature was 4 degrees C. The air and floor temperature for condition F were 21 and 29 degrees C, respectively. The air temperature for condition C was 15 degrees C. There were no significant differences in rectal temperature and mean skin temperature between condition A and F. Systolic blood pressure of the elderly men in condition C significantly increased compared to those in condition A and F. No significant differences in systolic blood pressure between condition A and F were found. The percentage of subjects who felt comfortable under condition F was higher than that of those under condition A in both age groups, though the differences between condition F and A was not significant. Relationships between thermal comfort and peripheral (e.g., instep, calf, hand) skin temperature, and the relationship between thermal comfort and leg thermal sensation were significant for both age groups. However, the back and chest skin temperature and back thermal sensation for the elderly, in contrast to that for the young, was not significantly related to thermal comfort. These findings suggested that thermal responses and physiological strain using the floor heating system did not significantly differ from that using the air conditioning system, regardless of the subject age and despite the fact that the air temperature with the floor heating system was lower. An increase in BP for elderly was observed under the condition in which the air temperature was 15 degrees C, and it was suggested that it was necessary for the elderly

Experimental study of nonequilibrium post-chf heat transfer in rod bundles

International Nuclear Information System (INIS)

Unal, C.; Tuzla, K.; Badr, O.; Neti, S.; Chen, J.

1986-01-01

Verifications and improvements of nonequilibrium heat transfer models, for post-critical-heat-flux convective boiling, has been greatly affected by the lack of experimental data regarding the degree of thermodynamic nonequilibrium. Recent studies had been successful in measuring vapor superheats in a vertical single tube. This paper extends the nonequilibrium convective boiling data to a rod bundle geometry. Vapor superheat measurements were obtained in a rod bundle with nine heated rods and a heated shroud. Tests were carried out with water at low mass fluxes with a wide range of dryout conditions. Significant nonequilibrium was observed, with vapor superheats of up to 600 0 C. Parametric effects of mass flux, heat flux and inlet conditions on vapor superheat are presented

Field Measurement and Evaluation of the Passive and Active Solar Heating Systems for Residential Building Based on the Qinghai-Tibetan Plateau Case

Directory of Open Access Journals (Sweden)

Zhijian Liu

2017-10-01

Full Text Available Passive and active solar heating systems have drawn much attention and are widely used in residence buildings in the Qinghai-Tibetan plateau due to its high radiation intensity. In fact, there is still lack of quantitative evaluation of the passive and active heating effect, especially for residential building in the Qinghai-Tibetan plateau areas. In this study, three kinds of heating strategies, including reference condition, passive solar heating condition and active solar heating condition, were tested in one demonstration residential building. The hourly air temperatures of each room under different conditions were obtained and analyzed. The results show the indoor air temperature in the living room and bedrooms (core zones was much higher than that of other rooms under both passive and active solar heating conditions. In addition, the heating effect with different strategies for core zones of the building was evaluated by the ratio of indoor and outdoor degree hour, which indicates that solar heating could effectively reduce the traditional energy consumption and improve the indoor thermal environment. The passive solar heating could undertake 49.8% degree hours for heating under an evaluation criterion of 14 °C and the active solar heating could undertake 75% degree hours for heating under evaluation criterion of 18 °C, which indicated that solar heating could effectively reduce the traditional energy consumption and improve the indoor thermal environment in this area. These findings could provide reference for the design and application of solar heating in similar climate areas.

Experimental Investigation of the Combined Effects of Heat Exchanger Geometries on Nucleate Pool Boiling Heat Transfer in a Scaled IRWST

International Nuclear Information System (INIS)

Kang, Myeong Gie; Chun, Moon Hyun

1996-01-01

In an effort to determine the combined effects of major parameters of heat exchanger tubes on the nucleate pool boiling heat transfer in the scaled in-containment refueling water storage tank (IRWST), a total of 1,966 data for q v ersus ΔT has been obtained using various combinations of tube diameters, surface roughness, and tube orientations. The experimental results show that (1) increased surface roughness enhances heat transfer for both horizontal and vertical tubes, (2) the two heat transfer mechanisms, i.e.,enhanced heat transfer for both horizontal and vertical tubes, (2) the two heat transfer mechanisms, i.e., enhanced heat transfer due to liquid agitation by bubbles generated and reduced heat transfer by the formation of large vapor slugs and bubble coalescence are different in two regions of low heat fluxes (q ≤ 50kW/m 2 ) and high heat fluxes (q > 50kW/m 2 ) depending on the orientation of tubes and the degree of surface roughness, and (3) the heat transfer rate decreases as the tube diameter is increased for both horizontal and vertical tubes, but the effect of tube diameter on the nucleate pool boiling heat transfer for vertical tubes is greater than that for horizontal tubes. Two empirical heat transfer correlations for q , one for horizontal tubes and the other for vertical tubes, are obtained in terms of surface roughness (ε) and tube diameter (D). In addition, a simple empirical correlation for nucleate pool boiling heat transfer coefficient (h b ) is obtained as a function of heat flux (q ) only. 9 figs., 4 tabs., 15 refs. (Author)

Heat activation of Phycomyces blakesleeanus spores: theromdynamics and effect of alcohols, furfural, and high pressure.

Science.gov (United States)

Thevelein, J M; Van Assche, J A; Carlier, A R; Heremans, K

1979-08-01

The thermodynamic parameters for the heat activation of the sporangiospores of Phycomyces blakesleeanus were determined. For the apparent activation enthalpy (DeltaH(#)) a value of 1,151 kJ/mol was found, whereas a value of 3,644 J./ degrees K.mol was calculated for the apparent activation entropy (DeltaS(#)). n-Alcohols (from methanol to octanol), phenethyl alcohol, and furfural lowered the activation temperature of P. blakesleeanus spores. The heat resistance of the spores was lowered concomitantly. The effect of the alcohols was a linear function of the concentration in the range that could be applied. When the log of the concentration needed to produce an equal shift of the activation temperature was plotted for each alochol against the log of the octanol/water partition coefficient, a straight line was obtained. The free energy of adsorption of the n-alcohols to their active sites was calculated to be -2,487 J/mol of CH(2) groups. Although still inconclusive, this points toward an involvement of protein in the activation process. The effect of phenethyl alcohol was similar to the effect of n-alcohols, but furfural produced a greater shift than would be expected from the value of its partition coefficient. When the heat activation of the spores was performed under high pressure, the activation temperature was raised by 2 to 4 degrees K/1,000 atm. However, with pressures higher than 1,000 atm (1.013 x 10(5) kPa) the activation temperature was lowered until the pressure became lethal (more than 2,500 atm). It is known that membrane phase transition temperatures are shifted upward by about 20 degrees K/1,000 atm and that protein conformational changes are shifted upward by 2 to 6 degrees K/1,000 atm. Consequently, heat activation of fungal spores seems to be triggered by a protein conformational change and not by a membrane phase transition. Activation volumes of -54.1 cm(3)/mol at 38 degrees C and -79.3 cm(2)/mol at 40 degrees C were found for the lowering effect

Thermodynamics of ion binding to phosphatidic acid bilayers. Titration calorimetry of the heat of dissociation of DMPA.

Science.gov (United States)

Blume, A; Tuchtenhagen, J

1992-05-19

The heat of dissociation of the second proton of 1,2-dimyristoylphosphatidic acid (DMPA) was studied as a function of temperature using titration calorimetry. The dissociation of the second proton of DMPA was induced by addition of NaOH. From the calorimetric titration experiment, the intrinsic pK0 for the dissociation reaction could be determined by applying the Gouy-Chapman theory. pK0 decreases with temperature from ca. 6.2 at 11 degrees C to 5.4 at 54 degrees C. From the total heat of reaction, the dissociation enthalpy, delta Hdiss, was determined by subtracting the heat of neutralization of water and the heat of dilution of NaOH. In the temperature range between 2 and 23 degrees C, delta Hdiss is endothermic with an average value of ca. 2.5 kcal.mol-1 and shows no clear-cut temperature dependence. In the temperature range between 23 and 52 degrees C, delta Hdiss calculated after subtraction of the heat of neutralization and dilution is not the true dissociation enthalpy but includes contributions from the phase transition enthalpy, delta Htrans, as the pH jump induces a transition from the gel to the liquid-crystalline phase. The delta Cp for the reaction enthalpy observed in this temperature range is positive. Above 53 degrees C, the pH jump induces again only the dissociation of the second proton, and the bilayers stay in the liquid-crystalline phase. In this temperature range, delta Hdiss seems to decrease with temperature. The thermodynamic data from titration calorimetry and differential scanning calorimetry as a function of pH can be combined to construct a complete enthalpy-temperature diagram of DMPA in its two ionization states.

Effect of degree of lipomobilization on results of glucose test in dairy cows in heat stress

Directory of Open Access Journals (Sweden)

Cincović M.R.

2012-01-01

Full Text Available Cows exposed to heat stress exhibit a decreased ability to mobilize lipids due to increased sensitivity to insulin, which is expressed in a decreased concentration of NEFA. However, certain cows can preserve the level of lipid mobilization after adapting to heat stress. We assumed that cows that have a preserved ability to mobilize lipids are less sensitive to insulin and that they have a lower tolerance for glucose. The aim of this work was to compare the results of an intravenous glucose tolerance test in cows that exhibited, in prolonged heat stress, a decreased (NEFA0.30 mmol/l ability for lipid mobilization. Glucose concentration and NEFA concentration were measured following intravenous application of glucose. The mean glycaemic index value did not differ statistically significantly between the two groups of cows at 10, 15 and 20 minutes after glucose application (p>0.05, but there was a tendency at 10 and 15 minutes for the glycaemia to be higher in cows with preserved lipomobilization (p<0.1. At 30, 60 and 90 minutes after glucose application, glycaemia was statistically significantly higher (p<0.01; p<0.05 and p<0.05 in the group of cows with preserved lipomobilization. The glycaemic index values (mmol/l shown in the same order (30, 60 and 90 minutes were as follows 9.91±0.21: 9.23±0.41; 5.41±0.5: 4.67±0.33 and 4.31±0.39: 3.47±0.37. The mean value for NEFA concentration in samples originating from the two experimental groups of cows did not differ statistically significantly following glucose application. The NEFA concentration showed a tendency to be higher in cows with preserved lipid mobilization in comparison with cows with decreased lipomobilization at 20 and 30 minutes after glucose application (p<0.1. Following the intravenous glucose tolerance test, NEFA and glucose concentrations were in a significant negative correlation, and that correlation was more expressed in cows with decreased lipomobilization. Cows with preserved

Effects of heat stress on serum insulin, adipokines, AMP-activated protein kinase, and heat shock signal molecules in dairy cows.

Science.gov (United States)

Min, Li; Cheng, Jian-bo; Shi, Bao-lu; Yang, Hong-jian; Zheng, Nan; Wang, Jia-qi

2015-06-01

Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperature-humidity index (THI) is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is difficult to ascertain whether THI is the most appropriate measurement of heat stress in dairy cows. This experiment was conducted to investigate the effects of heat stress on serum insulin, adipokines (leptin and adiponectin), AMP-activated protein kinase (AMPK), and heat shock signal molecules (heat shock transcription factor (HSF) and heat shock proteins (HSP)) in dairy cows and to research biomarkers to be used for better understanding the meaning of THI as a bioclimatic index. To achieve these objectives, two experiments were performed. The first experiment: eighteen lactating Holstein dairy cows were used. The treatments were: heat stress (HS, THI average=81.7, n=9) and cooling (CL, THI average=53.4, n=9). Samples of HS were obtained on August 16, 2013, and samples of CL were collected on April 7, 2014 in natural conditions. The second experiment: HS treatment cows (n=9) from the first experiment were fed for 8 weeks from August 16, 2013 to October 12, 2013. Samples for moderate heat stress, mild heat stress, and no heat stress were obtained, respectively, according to the physical alterations of the THI. Results showed that heat stress significantly increased the serum adiponectin, AMPK, HSF, HSP27, HSP70, and HSP90 (Pdairy cows. When heat stress treatment lasted 8 weeks, a higher expression of HSF and HSP70 was observed under moderate heat stress. Serum HSF and HSP70 are sensitive and accurate in heat stress and they could be potential indicators of animal response to heat stress. We recommend serum HSF and HSP70 as meaningful biomarkers to supplement the THI and evaluate moderate heat stress in dairy cows in the future.

Skin cooling maintains cerebral blood flow velocity and orthostatic tolerance during tilting in heated humans

Science.gov (United States)

Wilson, Thad E.; Cui, Jian; Zhang, Rong; Witkowski, Sarah; Crandall, Craig G.

2002-01-01

Orthostatic tolerance is reduced in the heat-stressed human. The purpose of this project was to identify whether skin-surface cooling improves orthostatic tolerance. Nine subjects were exposed to 10 min of 60 degrees head-up tilting in each of four conditions: normothermia (NT-tilt), heat stress (HT-tilt), normothermia plus skin-surface cooling 1 min before and throughout tilting (NT-tilt(cool)), and heat stress plus skin-surface cooling 1 min before and throughout tilting (HT-tilt(cool)). Heating and cooling were accomplished by perfusing 46 and 15 degrees C water, respectively, though a tube-lined suit worn by each subject. During HT-tilt, four of nine subjects developed presyncopal symptoms resulting in the termination of the tilt test. In contrast, no subject experienced presyncopal symptoms during NT-tilt, NT-tilt(cool), or HT-tilt(cool). During the HT-tilt procedure, mean arterial blood pressure (MAP) and cerebral blood flow velocity (CBFV) decreased. However, during HT-tilt(cool), MAP, total peripheral resistance, and CBFV were significantly greater relative to HT-tilt (all P heat-stressed humans.

Process for making 90 degree K. superconductors by impregnating cellulosic article with precursor solution

International Nuclear Information System (INIS)

Bolt, J.D.; Subramanian, M.A.

1991-01-01

This patent describes an improved process for preparing a shaped article of a superconducting composition having the formula MBa 2 Cu 3 O x wherein; M is selected from the group consisting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu; x is from about 6.5 to about 7.0; the composition having a superconducting transition temperature of about 90 K. It comprises: forming in acetic acid a mixture of M(C 2 H 3 O 2 ) 3 , barium acetate and copper acetate in an atomic ratio of M:Ba:Cu of about 1:2:3; heating the resulting mixture to boiling, and adding sufficient formic acid to dissolve any undissolved starting material while continuing to boil the solution; contacting an article of cellulose material with the solution thereby impregnating the article with the solution, the article having the shape desired; removing excess solution from the resulting impregnated article of cellulose material and drying the impregnated article; heating the impregnated article of cellulose material to a temperature from about 850 degree C to about 925 degree C in an oxygen-containing atmosphere for a time sufficient to form MBa 2 Cu 3 O y , where y is from about 6.0 to about 6.5, the heating effecting carbonization of the cellulose material and oxidization of carbon without ignition; and maintaining the resulting article in an oxygen-containing atmosphere while cooling for a time sufficient to obtained the desired product

Effect of heat treatment upon the fatigue-crack growth behavior of Alloy 718 weldments

International Nuclear Information System (INIS)

James, L.A.; Mills, W.J.

1981-05-01

Gas-tungsten-arc weldments in Alloy 718 were studied in fatigue-crack growth test conducted at five temperatures over the range 24--649 degree C. In general, crack growth rates increased with increasing temperature, and weldments given the ''conventional'' post-weld heat-treatment generally exhibited crack growth rates that were higher than for weldments given the ''modified'' (INEL) heat-treatment. Limited testing in the as-welded condition revealed crack growth rates significantly lower than observed for the heat-treated cases, and this was attributed to residual stresses. Three different heats of filler wire were utilized, and no heat-to-heat variations were noted. 23 refs., 9 figs., 6 tabs

Numerical simulations of heat transfer distribution of a two-pass square channel with V-rib turbulator and bleed holes

Science.gov (United States)

Kumar, Sourabh; Amano, R. S.; Lucci, Jose Martinez

2013-08-01

The blade tip region in gas turbine encounters high thermal loads due to temperature difference and hence efforts for high durability and safe operations are essential. Improved and robust methods of cooling are required to downgrade heat transfer rate to turbine blades. The blade tip regions, which are exposed to high gas flow, suffers high local thermal load which are due to external tip leakage. Jet impingement, pin cooling etc. are techniques used for cooling blades. A more usual way is to use serpentine passage with 180-degree turn. In this study, numerical simulation of heat transfer distribution of a two-pass square channel with rib turbulators and bleed holes were done. Periodical rib turbulators and bleed holes were used in the channel. The ribs arrangement were 60 degree V rib, 60 degree inverted V ribs, combination of 60 degree V rib at inlet and 60 inverted V rib at outlet section and combination of Inverted V at inlet and V rib at the outlet. The results were numerically computed using Fluent with Reynolds number of 12,500 and 28,500. Turbulence models used for computations were k-ω-SST and RSM. Temperature based and shear stress based techniques were used for heat transfer distribution prediction. The results for 60 degree V rib, 60 degree inverted V ribs were compared with the experimental results for validation of the results obtained. Detailed distribution shows distinctive peaks in heat transfer around bleed holes and rib turbulator. Comparisons of the overall performance of the models with different orientation of rib turbulator are presented. It is found that due to the combination of 60 degree inverted V rib in inlet and 60 V rib in outlet with bleed holes provides better heat treatment. It is suggested that the use of rib turbulator with bleed holes provides suitable for augmenting blade cooling to achieve an optimal balance between thermal and mechanical design requirements.

Case study of low-temperature heating in an existing single-family house-A test of methods for simulation of heating system temperatures

DEFF Research Database (Denmark)

Østergaard, Dorte Skaarup; Svendsen, Svend

2016-01-01

and the calculated indoor temperatures and radiator return temperatures were compared to temperatures measured in the case house. The results showed that the detail of the simulation model has a large influence on the results obtained. The estimated return temperatures from the radiators varied by up to 16 degrees C...... depending on the assumptions made in the simulation model. The results indicated that a detailed building simulation model can provide a good estimate of the actual heating system operation, provided that actual radiators and realistic indoor temperatures are taken into account in the model. (C) 2016......Low-temperature heating provides an efficient way of heating our buildings. To obtain a high efficiency it is important that the heating systems in the buildings are operated with both low supply and return temperatures. This study set out to investigate how typical assumptions in the modelling...

Core Flooding Experiments and Reactive Transport Modeling of Seasonal Heat Storage in the Hot Deep Gassum Sandstone Formation

DEFF Research Database (Denmark)

Holmslykke, Hanne D.; Kjøller, Claus; Fabricius, Ida Lykke

2017-01-01

Seasonal storage of excess heat in hot deep aquifers is considered to optimize the usage of commonly available energy sources. The chemical effects of heating the Gassum Sandstone Formation to up to 150 degrees C is investigated by combining laboratory core flooding experiments with petrographic ...... minor effects on the properties of the reservoir and that storage of excess heat in the Gassum Formation in the Stenlille area may be possible provided operational precautions are taken....... analysis and geochemical modeling. Synthetic formation water is injected into two sets of Gassum Formation samples at 25, 50 (reservoir temperature), 100, and 150 degrees C with a velocity of 0.05 and 0.1 PV/h, respectively. Results show a significant increase in the aqueous concentration of silicium...... and iron with increasing temperature due to dissolution of silica and siderite. Increasing the reservoir temperature from 50 to 100 degrees C enhanced the naturally occurring weathering of Na-rich feldspar to kaolinite. Dissolution of quartz increased sharply above 100 degrees C and was the dominating...

Geothermal energy. Ground source heat pumps

International Nuclear Information System (INIS)

2009-01-01

Geothermal energy can be harnessed in 2 different ways: electricity or heat generation. The combined net electrical geothermal power of the European Union countries reached 719.3 MWe in 2008 (4.8 MW up on 2007) for 868.1 MWe of installed capacity. Gross electrical production contracted slightly in 2008 (down 1% on the 2007 level) and stood at 5809.5 GWh in 2008. Italy has a overwhelming position with a production of 5520.3 GWh. Geothermal heat production concerning aquifers whose temperature is 30-150 C. degrees generally at a depth of 1-3 km is called low- and medium-enthalpy energy. 18 of the 27 EU members use low- and medium-enthalpy energy totaling 2560.0 MWth of installed capacity that yielded 689.2 ktoe in 2008 and 3 countries Hungary, Italy and France totaling 480.3 ktoe. Very low-enthalpy energy concerns the exploitation of shallow geothermal resources using geothermal heat pumps. In 2008, 114452 ground heat pumps were sold in Europe. At the end of 2008, the installed capacity was 8955.4 MWth (16.5% up on 2007 level, it represented 785206 pumps. Over one million ground heat pumps are expected to be operating in 2010 in Europe. (A.C.)

Noxious heat and scratching decrease histamine-induced itch and skin blood flow.

Science.gov (United States)

Yosipovitch, Gil; Fast, Katharine; Bernhard, Jeffrey D

2005-12-01

The aim of this study was to assess the effect of thermal stimuli or distal scratching on skin blood flow and histamine-induced itch in healthy volunteers. Twenty-one healthy volunteers participated in the study. Baseline measurements of skin blood flow were obtained on the flexor aspect of the forearm. These measurements were compared with skin blood flow after various stimuli: heating the skin, cooling the skin, noxious cold 2 degrees C, noxious heat 49 degrees C, and scratching via a brush with controlled pressure. Afterwards histamine iontophoresis was performed and skin blood flow and itch intensity were measured immediately after the above-mentioned stimuli. Scratching reduced mean histamine-induced skin blood flow and itch intensity. Noxious heat pain increased basal skin blood flow but reduced histamine-induced maximal skin blood flow and itch intensity. Cold pain and cooling reduced itch intensity, but neither affected histamine-induced skin blood flow. Sub-noxious warming the skin did not affect the skin blood flow or itch intensity. These findings suggest that heat pain and scratching may inhibit itch through a neurogenic mechanism that also affects skin blood flow.

SiO2 sol-gel films after ammonia and heat two-step treatments

International Nuclear Information System (INIS)

Zhang Chunlai; Wang Biyi; Tian Dongbin; Yin Wei; Jiang Xiaodong; Yuan Xiaodong; Yan Lianghong; Zhang Hongliang; Zhao Songnan; Lv Haibing

2008-01-01

SiO 2 thin films were deposited using tetraethoxylsilane as precursor, ammonia as catalyst on K9 glass by sol-gel method. These films were post-treated by ammonia and heat. The properties of the coatings were characterized by ellipsometer, UV-vis spectrophotometry, FTIR-spectroscopy, scanning probe microscope and contact angle measurement apparatus. The resuits indicate that the thickness of the films with ammonia and heat treatment tend to decrease. Both the refractive index and water contact angle increase after ammonia treatment. However, they both decrease after heat treatment. The former increases by 0.236 for the first step, then decreases by 0.202 for the second. The latter increases to 58.92 degree, then decreases to 38.07 degree. The transmittance of the coatings turn to be better and continuously shift to short wave by UV-vis spectrophotometry. The surface becomes smoother by AFM after the two-step treatment. (authors)

Influence of Heat Treatments on Electrical Properties and Microstructure of 10 % Mass Fraction of Sucrose YBCO Superconductor

International Nuclear Information System (INIS)

Khalida Salleh; Fariesha, F.; Azhan, H.; Yusainee, S.Y.

2013-01-01

The influence of different heat treatments on the superconducting properties of 10 % mass fraction of sucrose structure YBCO superconductor was investigated. X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) equipment were used to determine the phase of superconductor and structural studies respectively at 10 % mass fraction of sucrose. The samples were prepared via solid state (SSM) and co-precipitation (CPM) reaction methods and underwent sintering and heat treatment process at 900, 930 and 960 degree Celsius respectively with mixing of C 12 H 22 O 11 sucrose during pelletization. The T C,on decreases with respect to higher heat treatment temperature. The suppression of both T C,on and T C,off indicates the destruction of superconductivity trends. The best T C,off were achieved in pure SSM and CPM samples sintered at 950 degree Celsius for 5 hours with T C,off 86 K and 91 K respectively. Comparing with pure YBCO, the 10 % mass fraction of sucrose YBCO exhibited higher critical current, I C by two times. It indicates the effect of high surface area in porous structure. The XRD results confirmed that all the samples remain in single phase, which indicates no effect of sucrose in the porous structures sample and maintaining in orthorhombic structure. Higher heat treatment at 960 degree Celsius resulted in destruction on its superconductivity behavior due to the partial melt phase on its microstructure, especially in CPM. This is due to the smaller grain size of samples which trapped more heat and causing partial melting to occur rapidly. It can be deduced that, annealing temperatures at 900 and 930 degree Celsius are the best optimum heat treatments for CPM and SSM porous superconductor, respectively. (author)

The effects of heated and room-temperature abdominal lavage solutions on core body temperature in dogs undergoing celiotomy.

Science.gov (United States)

Nawrocki, Michael A; McLaughlin, Ron; Hendrix, P K

2005-01-01

To document the magnitude of temperature elevation obtained with heated lavage solutions during abdominal lavage, 18 dogs were lavaged with sterile isotonic saline intraoperatively (i.e., during a celiotomy). In nine dogs, room-temperature saline was used. In the remaining nine dogs, saline heated to 43+/-2 degrees C (110+/-4 degrees F) was used. Esophageal, rectal, and tympanic temperatures were recorded every 60 seconds for 15 minutes after initiation of the lavage. Temperature levels decreased in dogs lavaged with room-temperature saline. Temperature levels increased significantly in dogs lavaged with heated saline after 2 to 6 minutes of lavage, and temperatures continued to increase throughout the 15-minute lavage period.

The effects of drying following heat shock exposure of the desert moss Syntrichia caninervis.

Science.gov (United States)

Xu, Shu-Jun; Liu, Chun-Jiang; Jiang, Ping-An; Cai, Wei-Min; Wang, Yan

2009-03-15

Desert mosses are components of biological soil crusts (BSCs) and their ecological functions make assessment and protection of these mosses a high-ranking management priority in desert regions. Drying is thought to be useful for desert mosses surviving heat shock. In this study, we investigated the role of drying by monitoring the responses of physiological characters and asexual reproduction in the typical desert moss Syntrichia caninervis. Heat significantly decreased chlorophyll content and weakened rapid recovery of photochemical activity, and increased carotenoid content and membrane permeability. Lethal temperatures significantly destroyed shoot regeneration potential. In comparison with heat alone, drying significantly increased protonema emergence time and depressed protonema emergence area. Drying combined with heat accelerated water loss, followed by a decrease of photosynthetic activity. Drying had different influences on membrane permeability at different temperatures. When moss leaves were subjected to a combined stress of drying and heat shock, photosynthesis was maintained mainly due to the effects of drying on physiological activity although the cellular morphological integrity was affected. Drying caused opposing effects on moss physiological and reproductive characteristics. On the one hand, drying caused a positive synergistic effect with heat shock when the temperature was below 40 degrees C. On the other hand, drying showed antagonism with heat shock when the moss was subjected to temperatures higher than 40 degrees C. These findings may help in understanding the survival mechanism of dessert mosses under heat shock stress which will be helpful for the artificial reconstruction of BSCs.

Design of SES-10 nuclear reactor for district heating

International Nuclear Information System (INIS)

Cuttler, J.M.

1991-03-01

The SES-10 units are unpressurized, pool-type nuclear reactors of 10MW rating, designed for supplying energy to hot water district heating systems, economically and without pollution. Water for heat distribution is brought to a maximum temperature of 85 degrees C. Conventional heating units supplement the output from SES-10 units for peak load and during maintenance. The SES-10 is housed in a low-cost building, with a double-walled pool in the ground. A naturally circulating primary system and a pumped secondary system transport heat from the reactor to the distribution system. The unit is fully automated and easy to maintain. Because of the many active and passive safety features, it is feasible to license the SES-10 for operation in a city and easy to explain it to the public for their acceptance. The core lasts approximately 43 months at a capacity factor of 70%, and the cost of heat is expected to be 2 to 2.5 cents/kWh

New Evidence that Magnetoconvection Drives Solar–Stellar Coronal Heating

Energy Technology Data Exchange (ETDEWEB)

Tiwari, Sanjiv K.; Panesar, Navdeep K.; Moore, Ronald L.; Winebarger, Amy R. [NASA Marshall Space Flight Center, Mail Code ST 13, Huntsville, AL 35812 (United States); Thalmann, Julia K., E-mail: sanjivtiwari80@gmail.com [Institute of Physics/IGAM, University of Graz, Universittsplatz 5/II, A-8010 Graz (Austria)

2017-07-10

How magnetic energy is injected and released in the solar corona, keeping it heated to several million degrees, remains elusive. Coronal heating generally increases with increasing magnetic field strength. From a comparison of a nonlinear force-free model of the three-dimensional active region coronal field to observed extreme-ultraviolet loops, we find that (1) umbra-to-umbra coronal loops, despite being rooted in the strongest magnetic flux, are invisible, and (2) the brightest loops have one foot in an umbra or penumbra and the other foot in another sunspot’s penumbra or in unipolar or mixed-polarity plage. The invisibility of umbra-to-umbra loops is new evidence that magnetoconvection drives solar-stellar coronal heating: evidently, the strong umbral field at both ends quenches the magnetoconvection and hence the heating. Broadly, our results indicate that depending on the field strength in both feet, the photospheric feet of a coronal loop on any convective star can either engender or quench coronal heating in the loop’s body.

Cost reduction in the cold: heat generated by terrestrial locomotion partly substitutes for thermoregulation costs in Knot Calidris canutus

NARCIS (Netherlands)

Bruinzeel, L.W.; Piersma, T.

1998-01-01

To test whether heat generated during locomotion substitutes for the thermoregulation cost, oxygen consumption of four post-absorptive temperate-wintering Knot Calidris canutus was measured at air temperatures of 25 degrees C (thermoneutral) and 10 degrees C (c. 10 degrees below the lower critical

Heat Transfer Analysis for a Fixed CST Column

International Nuclear Information System (INIS)

Lee, S.Y.

2004-01-01

In support of a small column ion exchange (SCIX) process for the Savannah River Site waste processing program, a transient two-dimensional heat transfer model that includes the conduction process neglecting the convection cooling mechanism inside the crystalline silicotitanate (CST) column has been constructed and heat transfer calculations made for the present design configurations. For this situation, a no process flow condition through the column was assumed as one of the reference conditions for the simulation of a loss-of-flow accident. A series of the modeling calculations has been performed using a computational heat transfer approach. Results for the baseline model indicate that transit times to reach 130 degrees Celsius maximum temperature of the CST-salt solution column are about 96 hours when the 20-in CST column with 300 Ci/liter heat generation source and 25 degrees Celsius initial column temperature is cooled by natural convection of external air as a primary heat transfer mechanism. The modeling results for the 28-in column equipped with water jacket systems on the external wall surface of the column and water coolant pipe at the center of the CST column demonstrate that the column loaded with 300 Ci/liter heat source can be maintained non-boiling indefinitely. Sensitivity calculations for several alternate column sizes, heat loads of the packed column, engineered cooling systems, and various ambient conditions at the exterior wall of the column have been performed under the reference conditions of the CST-salt solution to assess the impact of those parameters on the peak temperatures of the packed column for a given transient time. The results indicate that a water-coolant pipe at the center of the CST column filled with salt solution is the most effective one among the potential design parameters related to the thermal energy dissipation of decay heat load. It is noted that the cooling mechanism at the wall boundary of the column has significant

Aqueous partial molar heat capacities and volumes for NaReO4 and NaTcO4

International Nuclear Information System (INIS)

Lemire, R.J.; Saluja, P.P.S.; Campbell, A.B.

1989-01-01

As part of the Canadian Nuclear Fuel Waste Management Program, data are required to model the equilibrium thermodynamic behavior of key radionuclides at temperatures above 25 degree C. A flow microcalorimeter/densimeter system has been commissioned to measure heat capacities and densities of solutions containing radioactive species. Measurements for solutions of aqueous NaReO 4 (a common analogue for NaTcO 4 ) were made at seven temperatures (15 to 100 degree C) over the concentration range 0.05 to 0.2 mol·kg -1 . Subsequently, measurements were made for NaTcO 4 solutions under similar conditions. The heat capacity and density data are analyzed using Pitzer's ion-interaction model, and values of the NaReO 4 partial molar heat capacities are compared to literature values based on integral heats of solution. The agreement between the two sets of NaReO 4 data is good below 75 degree C, but only fair at the higher temperatures. Values of the partial molar volumes have also been derived. The uncertainties introduced by using thermodynamic data for ReO 4 - , in the absence of data for TcO 4 - , are discussed

Advanced Thermoelectric Materials for Efficient Waste Heat Recovery in Process Industries

Energy Technology Data Exchange (ETDEWEB)

Adam Polcyn; Moe Khaleel

2009-01-06

The overall objective of the project was to integrate advanced thermoelectric materials into a power generation device that could convert waste heat from an industrial process to electricity with an efficiency approaching 20%. Advanced thermoelectric materials were developed with figure-of-merit ZT of 1.5 at 275 degrees C. These materials were not successfully integrated into a power generation device. However, waste heat recovery was demonstrated from an industrial process (the combustion exhaust gas stream of an oxyfuel-fired flat glass melting furnace) using a commercially available (5% efficiency) thermoelectric generator coupled to a heat pipe. It was concluded that significant improvements both in thermoelectric material figure-of-merit and in cost-effective methods for capturing heat would be required to make thermoelectric waste heat recovery viable for widespread industrial application.

Modeling and Experimental Studies for the Thermal Performance of a Ground Heat Storage System Integrated with a Greenhouse

International Nuclear Information System (INIS)

Kooli, Sami; Lazaar, Mariem; Hazami, Majdi; Farhat, Abdelhamid; Belghith, Ali

2009-01-01

A thermal model has been developed to investigate the potential of using the stored thermal energy of the ground for greenhouse heating and cooling with the help of a ground heat storage system (GHSS) integrated with the greenhouse located in the premises of CRTEn, Tunis, Tunisia. Experiments were conducted extensively throughout the years 2006-2007, and the developed model was validated against several consecutive arbitrary days experiments. The predicted and measured values of the greenhouse air temperatures and humidities that were verified, in terms of root mean square deviation and correlation coefficient, exhibited fair agreement. The results of this study showed that the GHS system kept the inside air temperature 1-3 degree higher than that of outside air at nighttime. The main reason for this low efficiency is due to the weak heat transfer area of the water-air heat exchanger. The simulation results indicate that the GHSS does not yield any significant effect for cooling greenhouses during sunny daytime. The GHSS fulfils its full potential for a heat transfer area of 150 m 2 . With this area, there occurs 4-6 degree rise of temperature in greenhouse as compared to the temperatures without GHSS and respectively 5-7.5 degree rise in greenhouse as compared to outside air

The Degree Cycle

DEFF Research Database (Denmark)

Wood, Johanna

2016-01-01

, empirical data relevant to the development of the degree adverb function is presented and possible relevant constructions identified. It is argued that the degree adverb function of that possibly occurs later than the historical dictionaries indicate. The degree adverb function of this is challenging...

Drying and heat decomposition of biomass during the production of biochar

Science.gov (United States)

Lyubov, V. K.; Popova, E. I.

2017-11-01

The process of wood torrefaction provides an opportunity to combine properties of biofuel and steam coal. Different degrees of biofuel heat treating leads to varied outcomes and varied biochar heating value. Therefore, the torrefaction process requires optimal operation that ensures the highest heating value of biochar with the lowest energy loss. In this paper we present the experimental results of drying cycle and thermal decomposition of particles of spruce stem wood and hydrolytic lignin in argon under various temperature conditions and basic material humidity as well as changes in the morphological structure of the biomass and its grain size composition during the torrefaction.

Comparative assessment of chlorine, heat, ozone, and UV light for killing Legionella pneumophila within a model plumbing system

International Nuclear Information System (INIS)

Muraca, P.; Stout, J.E.; Yu, V.L.

1987-01-01

Nosocomial Legionnaires disease can be acquired by exposure to the organism from the hospital water distribution system. As a result, many hospitals have instituted eradication procedures, including hypercholorination and thermal eradication. We compared the efficacy of ozonation, UV light, hyperchlorination, and heat eradication using a model plumbing system constructed of copper piping, brass spigots, Plexiglas reservoir, electric hot water tank, and a pump. Legionella pneumophila was added to the system at 10(7) CFU/ml. Each method was tested under three conditions; (i) nonturbid water at 25 degrees C, (ii) turbid water at 25 degrees C, and (iii) nonturbid water at 43 degrees C. UV light and heat killed L. pneumophila most rapidly and required minimal maintenance. Both UV light and heat (60 degrees C) produced a 5 log kill in less than 1 h. In contrast, both chlorine and ozone required 5 h of exposure to produce a 5 log decrease. Neither turbidity nor the higher temperature of 43 degrees C impaired the efficacy of any of the disinfectant methods. Surprisingly, higher temperature enhanced the disinfecting efficacy of chlorine. However, higher temperature accelerated the decomposition of the chlorine residual such that an additional 120% volume of chlorine was required. All four methods proved efficacious in eradicating L. pneumophila from a model plumbing system

On the question of heat engine cycles optimization

Directory of Open Access Journals (Sweden)

Костянтин Ігорович Ткаченко

2015-10-01

Full Text Available It is known that the efficiency of heat engines nowadays isn’t more than 50-60% for prototypes and maximum possible efficiency of a heat engine is considered Carnot cycle efficiency Thus, at least 40% of the disposable amount of heat is lost in the surrounding medium, unless the waste gases heat is utilized somehow. General idea of heat engines cycles is the transfer of energy from the heater (both external and internal to a working fluid, obtaining mechanical work from expanding of the working fluid, and returning the working fluid to the initial state by compression and excess heat discharge into a cooler. In this paper the combination of a heat engine operating according to the standard Edwards cycle and consisting of isochor, adiabat and isotherm, and the heat pump, using the reverse Carnot cycle is investigated. The heat pump partially picks out the heat of the working fluid at its isothermal compression, and returns it to the equivalent working fluid or regenerator cap, at the beginning of isochoric heating. The efficiency coefficient of the heat pump, and thus the work to putting it into action is calculated by proper equations at the constant temperature of the low-potential heat source (working fluid and variable temperature of the heated equivalent of the working fluid or the regenerator cap. Taking as an example selected quantitative parameters of the Edwards cycle it has been proved that the use of the heat pump increases the effective efficiency of combined cycle as compared to the basic one. In addition, it has been shown that the dependence of the efficiency on the degree of heat return is not monotonic and has a maximum

Kinetic modelling of reactions in heated disaccharide-casein systems

NARCIS (Netherlands)

Brands, C.M.J.; Boekel, van M.A.J.S.

2003-01-01

The reactions occurring in disaccharide-casein reaction mixtures during heating at 120 degreesC and pH 6.8 were studied. The existence of two main degradation routes were established: (1) Isomerisation of the aldose sugars lactose and maltose in their ketose isomers lactulose and maltulose,

Oesophageal heat transfer properties indication of segmental blood flow changes during distension

DEFF Research Database (Denmark)

Liao, Donghua; Frøkjær, Jens Brøndum; Brock, Christina

2008-01-01

The pain perception to distension of the oesophagus can be explained by activation of receptors responding to mechanical deformation or to distension-induced ischaemia. The aim of this study was to develop a new method for detection of changes in segmental blood flow during distension based...... on measurement of heat transfer. A bag was distended in the distal oesophagus of six healthy subjects followed by cooling or heating of the bag fluid to 5 or 60 degrees C. After equilibrium, the temperature was allowed to change back to body temperature. The temperature was recorded together with intraluminal...... ultrasound imaging, allowing assessment of the heat transfer properties at different bag volumes. The heat transfer constants were higher after heating the bag than after cooling the bag (Tukey, P

HOUSEHOLD HEATING IN THE LIGHT OF CLIMATE CHANGE

Directory of Open Access Journals (Sweden)

MÓNIKA PALÁDI

2014-12-01

Full Text Available Greenhouse gas emissions resulting from anthropogenic activities play a significant role in climate change. The residential heating should be mentioned one of the main polluting source of greenhouse gases.This paper aims to give a comprehensive view about the amount of CO2 emission as well as objectives and strategies for reduction the GHG emission. In addition, we illustrate the example of an average Hungarian family house (100 m2 , that biomass-based energy production what extent can reduce the current very high degree carbon dioxide emissions. We prepared investment analysis, as to what kind of ecological and economic benefits may result in heating modernization projects of a four-member family home. Additionally, a calculation method of CO2 emission from heating is demonstrated on the basis of IPPC report (2006; the role of biomass is explained in heating; furthermore I give an overview analysis about the significance of forests for reduction of CO2 concentration.

Pre-heating mitigates composite degradation.

Science.gov (United States)

Silva, Jessika Calixto da; Rogério Vieira, Reges; Rege, Inara Carneiro Costa; Cruz, Carlos Alberto dos Santos; Vaz, Luís Geraldo; Estrela, Carlos; Castro, Fabrício Luscino Alves de

2015-01-01

Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm) and the composites Durafill VS (Heraeus Kulzer), Z-250 (3M/ESPE), and Z-350 (3M/ESPE), cured at 25°C (no pre-heating) or 60°C (pre-heating). Specimens were stored sequentially in the following solutions: 1) water for 7 days (60°C), plus 0.1 N sodium hydroxide (NaOH) for 14 days (60°C); 2) 50% silver nitrate (AgNO3) for 10 days (60°C). Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey's tests (α=5%). Results Radiopacity levels were as follows: Durafill VSZ-350>Z-250 (pheated specimens presented higher radiopacity values than non-pre-heated specimens (pheated specimens (pheating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth.

Irreversibility analysis for optimization design of plate fin heat exchangers using a multi-objective cuckoo search algorithm

International Nuclear Information System (INIS)

Wang, Zhe; Li, Yanzhong

2015-01-01

Highlights: • The first application of IMOCS for plate-fin heat exchanger design. • Irreversibility degrees of heat transfer and fluid friction are minimized. • Trade-off of efficiency, total cost and pumping power is achieved. • Both EGM and EDM methods have been compared in the optimization of PFHE. • This study has superiority over other single-objective optimization design. - Abstract: This paper introduces and applies an improved multi-objective cuckoo search (IMOCS) algorithm, a novel met-heuristic optimization algorithm based on cuckoo breeding behavior, for the multi-objective optimization design of plate-fin heat exchangers (PFHEs). A modified irreversibility degree of the PFHE is separated into heat transfer and fluid friction irreversibility degrees which are adopted as two initial objective functions to be minimized simultaneously for narrowing the search scope of the design. The maximization efficiency, minimization of pumping power, and total annual cost are considered final objective functions. Results obtained from a two dimensional normalized Pareto-optimal frontier clearly demonstrate the trade-off between heat transfer and fluid friction irreversibility. Moreover, a three dimensional Pareto-optimal frontier reveals a relationship between efficiency, total annual cost, and pumping power in the PFHE design. Three examples presented here further demonstrate that the presented method is able to obtain optimum solutions with higher accuracy, lower irreversibility, and fewer iterations as compared to the previous methods and single-objective design approaches

USE OF PELTIER COOLERS AS SOIL HEAT FLUX TRANSDUCERS.

Science.gov (United States)

Weaver, H.L.; Campbell, G.S.

1985-01-01

Peltier coolers were modified and calibrated to serve as soil heat flux transducers. The modification was to fill their interiors with epoxy. The average calibration constant on 21 units was 13. 6 plus or minus 0. 8 kW m** minus **2 V** minus **1 at 20 degree C. This sensitivity is about eight times that of the two thermopile transducers with which comparisons were made. The thermal conductivity of the Peltier cooler transducers was 0. 4 W m** minus **1 degree C** minus **1, which is comparable to that of dry soil.

Correction factors and performance of a 4 degrees C sealed water calorimeter.

Science.gov (United States)

Seuntjens, J; Palmans, H

1999-03-01

In the past two decades, the water calorimetry technique for determination of absorbed dose to water in several types of radiation beams has moved significantly closer to being a recognized method. In this paper we summarize the constructional details of a 4 degrees C sealed water calorimeter currently in operation at the University of Gent. This sealed water (SW) calorimeter is of the Domen type and has been improved in several aspects compared with its original design. The relevant correction factors for heat transport and for field perturbation are described. Using relative response measurements in 60Co, we experimentally verified the relative heat defect for two distinct chemical systems, using two different detection vessel arrangements. The overall 1sigma uncertainty on the absorbed dose to water at 60Co based on this system amounts to 0.7%.

Heat radiation approach for harnessing heat of the cook stove to generate electricity for lighting system and charging of mobile phone

Science.gov (United States)

Muñoz, Rodrigo C., Jr.; Manansala, Chad Deo G.

2018-01-01

This study is based on the potential of thermoelectric coupling such as the thermoelectric cooler module. A thermoelectric cooler converts the heat coming from the cook stove into electricity and store in a battery. A dc-dc boost converter will be used to produce enough voltage to light a minimum house dwelling or charge phone battery. This device will be helpful to those that faces a problem on electricity especially in the isolated areas. The study aims (1) to harness heat from the cook stove up to 110 °C (2) To automatically cool-off the system to protect the thermoelectric cooler from damage due to excessive heat using an electronic solenoid; (3) To store energy harnessed in the battery; (4) To amplify the output voltages of the battery using DC to DC boost converter for lighting system and charging of mobile phone battery. From various tests conducted, it can fully charge a mobile phone in 3 hours observing the unit’s battery voltage drop from 4.06V to 3.98V. In the testing it used different orientation of steel rod by conduction to transfer heat and by radiation through tubular steel with its different dimensions. Most recent testing proved that the 2x2x9 tubular steel by radiation had the best result. The temperature reached more than a hundred degree Celsius that met the objective. The test resulted of boosting the voltage of the battery output from 3.7V to 4.96V on the average. The boosted voltage decrease as the system’s cool-off mechanism operated when the temperature reached above 110 degree Celsius decreasing output voltage to 0.8V resulting the boosted voltage to drop to zero. Therefore, the proponents concluded that heat waste can be converted to electrical energy by harnessing heat through radiation, with the help of TEC that generates voltage for lighting and can be boosted to be used for mobile charging. Furthermore, the study proved that the excess heat can damaged the TEC which was prevented by using of cooling-off mechanism, making it more

Microcalorimetric measurements of heat production in human erythrocytes. IV. Comparison between different calorimetric techniques, suspension media, and preparation methods.

Science.gov (United States)

Monti, M; Wadsö, I

1976-10-01

Heat production in human erythrocytes from healthy subjects has been measured under different experimental conditions. Simultaneous measurements were made on the same samples using different types of microcalorimeters: a static ampoule calorimeter, an air perfusion calorimeter, and a flow calorimeter. Obtained heat effect values for specified standard conditions, P degrees, were within uncertainty limits the same for the different calorimeters. Cells were suspended either in autologous plasma or in a phosphate buffer. P degrees values for buffer suspensions were significantly higher than those for plasma suspensions. Erythrocyte samples prepared by the column adsorption technique gave higher P degrees values than those obtained by a conventional centrifugation procedure.

Influence of local noxious heat stimulation on sensory nerve activity in the feline dental pulp.

Science.gov (United States)

Ahlberg, K F

1978-05-01

The present investigation was undertaken to develop an experimental model in which noxious heat stimulation was used to produce increased intradental sensory nerve activity in canine teeth of anesthetized cats. Two techniques were evaluated in which both the method of recording and the nature of the stimulus varied. Slow heating (approx 1 degree C/s) to 47 degree C of the tooth surface (combined with recording from electrodes in open dentinal cavities) did not produce any persistent nerve activity. Repeated periods of brief intense heating (approx 60 degrees C/s) (combined with recording from amalgam electrodes placed on cavity floors) resulted in an immediate response and an afterdischarge (phase 3) generally persisting for 20--60 min. Maximum phase 3 activity was characteristic for the individual cat and ranged from 0.2 to 50.2 imp/s. mean value 10.6 imp/s (S.D. +/- 9.2). A systematically higher phase 3 activity was recorded in lower compared to upper canine teeth (p less than 0.05). The maximum phase 3 response generally occurred after 3-8 stimulations; the median number of required stimuli was 3. Repeated brief heat stimulations combined with the closed cavity recording technique may be used as an experimental model by which the mechanisms behind increases in intradental sensory nerve activity associated with tissue damage can be studied.

Proposed experiment to investigate use of heated optical fibers for tokamak diagnostics during D-T discharges

International Nuclear Information System (INIS)

Tighe, W.; Morgan, P.; Griscom, D.; Adler, H.; Cylinder, D.; Johnson, D.; Palladino, D.; Ramsey, A.

1995-02-01

A collaborative JET/TFTR study has been undertaken to investigate attenuation and luminescence effects due to neutron irradiation of optical fibers heated to 400 degrees C. It is expected that a significant improvement in fiber behavior will be observed due to thermal annealing. This technique may be important for use in fiber-related, tokamak diagnostics exposed to high neutron flux. The study will make use of aluminum jacketed, 600 μm diameter, all silica (F-doped cladding) fibers in lengths of 150 m. The fibers are prepared in 1 foot coils. Of the coils to be irradiated, one is heated constantly to 400 degrees C, a second is not heated, and a third is heated periodically. A fourth fiber coil is not to be irradiated. Spectrally and temporally resolved transmission and luminescence data under neutron irradiation during D-T discharges on TFTR will be obtained. An investigation of permanent and short term effects will be made. Experimental details along with initial results will be presented

The thermoelectric generators use for waste heat utilization from cement plant

Directory of Open Access Journals (Sweden)

Sztekler Karol

2017-01-01

Production often entails the formation of by-product which is waste heat. One of the equipment processing heat into electricity is a thermoelectric generator. Its operation is based on the principle of thermoelectric phenomenon, which is known as a Seebeck phenomenon. The simplicity of thermoelectric phenomena allows its use in various industries, in which the main waste product is in the form of heat with the temperature of several hundred degrees. The study analyses the possibility of the thermoelectric systems use for the waste heat utilization resulting in the cement production at the cement plant. The location and design of the thermoelectric system that could be implemented in cement plant is chosen. The analysis has been prepared in the IPSEpro software.

Effects of heat stress on serum insulin, adipokines, AMP-activated protein kinase, and heat shock signal molecules in dairy cows*

Science.gov (United States)

Min, Li; Cheng, Jian-bo; Shi, Bao-lu; Yang, Hong-jian; Zheng, Nan; Wang, Jia-qi

2015-01-01

Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperature-humidity index (THI) is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is difficult to ascertain whether THI is the most appropriate measurement of heat stress in dairy cows. This experiment was conducted to investigate the effects of heat stress on serum insulin, adipokines (leptin and adiponectin), AMP-activated protein kinase (AMPK), and heat shock signal molecules (heat shock transcription factor (HSF) and heat shock proteins (HSP)) in dairy cows and to research biomarkers to be used for better understanding the meaning of THI as a bioclimatic index. To achieve these objectives, two experiments were performed. The first experiment: eighteen lactating Holstein dairy cows were used. The treatments were: heat stress (HS, THI average=81.7, n=9) and cooling (CL, THI average=53.4, n=9). Samples of HS were obtained on August 16, 2013, and samples of CL were collected on April 7, 2014 in natural conditions. The second experiment: HS treatment cows (n=9) from the first experiment were fed for 8 weeks from August 16, 2013 to October 12, 2013. Samples for moderate heat stress, mild heat stress, and no heat stress were obtained, respectively, according to the physical alterations of the THI. Results showed that heat stress significantly increased the serum adiponectin, AMPK, HSF, HSP27, HSP70, and HSP90 (Pheat-stressed dairy cows. When heat stress treatment lasted 8 weeks, a higher expression of HSF and HSP70 was observed under moderate heat stress. Serum HSF and HSP70 are sensitive and accurate in heat stress and they could be potential indicators of animal response to heat stress. We recommend serum HSF and HSP70 as meaningful biomarkers to supplement the THI and evaluate moderate heat stress in dairy cows in the future. PMID:26055916

Effects of Induction Heat Bending and Heat Treatment on the Boric Acid Corrosion of Low Alloy Steel Pipe for Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Kim, Ki-Tae; Kim, Young-Sik [Andong National University, Gyeongbuk (Korea, Republic of); Chang, Hyun-Young; Park, Heung-Bae [KEPCO EandC, Gyeongbuk (Korea, Republic of); Sung, Gi-Ho; Shin, Min-Chul [Sungil SIM Co. Ltd, Busan (Korea, Republic of)

2016-11-15

In many plants, including nuclear power plants, pipelines are composed of numerous fittings such as elbows. When plants use these fittings, welding points need to be increased, and the number of inspections also then increases. As an alternative to welding, the pipe bending process forms bent pipe by applying strain at low or high temperatures. This work investigates how heat treatment affects on the boric acid corrosion of ASME SA335 Gr. P22 caused by the induction heat bending process. Microstructure analysis and immersion corrosion tests were performed. It was shown that every area of the induction heat bent pipe exhibited a high corrosion rate in the boric acid corrosion test. This behavior was due to the enrichment of phosphorous in the ferrite phase, which occurred during the induction heat bending process. This caused the ferrite phase to act as a corrosion initiation site. However, when re-heat treatment was applied after the bending process, it enhanced corrosion resistance. It was proved that this resistance was closely related to the degree of the phosphorus segregation in the ferrite phase.

Natural convection heat transfer from a horizontal wavy surface in a porous enclosure

International Nuclear Information System (INIS)

Murthy, P.V.S.N.; Kumar, B.V.R.; Singh, P.

1997-01-01

The effect of surface undulations on the natural convection heat transfer from an isothermal surface in a Darcian fluid-saturated porous enclosure has been numerically analyzed using the finite element method on a graded nonuniform mesh system. The flow-driving Rayleigh number Ra together with the geometrical parameters of wave amplitude a, wave phase φ, and the number of waves N considered in the horizontal dimension of the cavity are found to influence the flow and heat transfer process in the enclosure. For Ra around 50 and above, the phenomenon of flow separation and reattachment is noticed on the walls of the enclosure. A periodic shift in the reattachment point from the bottom wall to the adjacent walls in the clockwise direction, leading to the manifestation of cycles of unicellular and bicellular clockwise and counterclockwise flows, is observed, with the phase varying between 0 degree and 350 degree. The counterflow in the secondary circulation zone is intensified with the increase in the value of Ra. The counterflow on the wavy wall hinders the heat transfer into the system. An increase in either wave amplitude or the number of waves considered per unit length decreases the global heat flux into the system. Only marginal changes in global heat flux are noticed with increasing Ra. On the whole, the comparison of global heat flux results in the wavy wall case with those of the horizontal flat wall case shows that, in a porous enclosure, the wavy wall reduces the heat transfer into the system

Optimal operation of integrated processes. Studies on heat recovery systems

Energy Technology Data Exchange (ETDEWEB)

Glemmestad, Bjoern

1997-12-31

Separators, reactors and a heat exchanger network (HEN) for heat recovery are important parts of an integrated plant. This thesis deals with the operation of HENs, in particular, optimal operation. The purpose of heat integration is to save energy, but the HEN also introduces new interactions and feedback into the overall plant. A prerequisite for optimisation is that there are extra degrees of freedom left after regulatory control is implemented. It is shown that extra degrees of freedom may not always be utilized for energy optimisation, and a quantitative expression for the degrees of freedom that can be so utilized are presented. A simplified expression that is often valid is also deduced. The thesis presents some improvements and generalisations of a structure based method that has been proposed earlier. Structural information is used to divide possible manipulations into three categories depending on how each manipulation affects the utility consumption. By means of these categories and two heuristic rules for operability, the possible manipulations are ordered in a priority table. This table is used to determine which manipulation should be preferred and which manipulation should be selected if an active manipulation is saturated. It is shown that the method may correspond to split-range control. A method that uses parametric information in addition to structural information is proposed. In this method, the optimal control structure is found through solving an integer programming problem. The thesis also proposes a method that combines the use of steady state optimisation and optimal selection of measurements. 86 refs., 46 figs., 8 tabs.

Effect of various refining processes for Kenaf Bast non-wood pulp fibers suspensions on heat transfer coefficient in circular pipe heat exchanger

Science.gov (United States)

Ahmed, Syed Muzamil; Kazi, S. N.; Khan, Ghulamullah; Sadri, Rad; Dahari, Mahidzal; Zubir, M. N. M.; Sayuti, M.; Ahmad, Pervaiz; Ibrahim, Rushdan

2018-03-01

Heat transfer coefficients were obtained for a range of non-wood kenaf bast pulp fiber suspensions flowing through a circular pipe heat exchanger test loop. The data were produced over a selected temperature and range of flow rates from the flow loop. It was found that the magnitude of the heat transfer coefficient of a fiber suspension is dependent on characteristics, concentration and pulping method of fiber. It was observed that at low concentration and high flow rates, the heat transfer coefficient values of suspensions were observed higher than that of the heat transfer coefficient values of water, on the other hand the heat transfer coefficient values of suspensions decreases at low flow rates and with the increase of their concentration. The heat transfer were affected by varying fiber characteristics, such as fiber length, fiber flexibility, fiber chemical and mechanical treatment as well as different pulping methods used to liberate the fibers. Heat transfer coefficient was decreased with the increase of fiber flexibility which was also observed by previous researchers. In the present work, the characteristics of fibers are correlated with the heat transfer coefficient of suspensions of the fibers. Deviations in fiber properties can be monitored from the flowing fiber suspensions by measuring heat transfer coefficient to adjust the degree of fiber refining treatment so that papers made from those fibers will be more uniform, consistent, within the product specification and retard the paper production loss.

Effects of heat treatment temperature on morphology and properties of opal crystal

International Nuclear Information System (INIS)

Duan Tao; China Academy of Engineering Physics, Mianyang; Peng Tongjiang; Chen Jiming; Tang Yongjian

2008-01-01

The monodispersed SiO 2 microspheres were synthesized by reactant mixed equally. The colloid crystal templates were assemblied by vertical sedimentation method in ethanol at certain temperatures, and the effects of the heat treatment temperature on the morphology and the properties of opal colloid crystals were investigated. SEM, TCr-DSC results indicate SiO 2 colloid templates should be heat treated at 700-800 degree C, enhancing the conglutination and mechanistic intensity of opal templates. UV-Vis analysis result indicates that the heat treatment process can remove the photonic band gap location of the opal colloid crystals, and with the heat treatment temperature increasing gradually, blue shift occurs and the gap narrows. (authors)

Soil microbial community structure across a thermal gradient following a geothermal heating event.

Science.gov (United States)

Norris, Tracy B; Wraith, Jon M; Castenholz, Richard W; McDermott, Timothy R

2002-12-01

In this study microbial species diversity was assessed across a landscape in Yellowstone National Park, where an abrupt increase in soil temperature had occurred due to recent geothermal activity. Soil temperatures were measured, and samples were taken across a temperature gradient (35 to 65 degrees C at a 15-cm depth) that spanned geothermally disturbed and unimpacted soils; thermally perturbed soils were visually apparent by the occurrence of dead or dying lodgepole pine trees. Changes in soil microbial diversity across the temperature gradient were qualitatively assessed based on 16S rRNA sequence variation as detected by denaturing gradient gel electrophoresis (DGGE) using both ribosomal DNA (rDNA) and rRNA as PCR templates and primers specific for the Bacteria or Archaea domain. The impact of the major heating disturbance was apparent in that DGGE profiles from heated soils appeared less complex than those from the unaffected soils. Phylogenetic analysis of a bacterial 16S rDNA PCR clone library from a recently heated soil showed that a majority of the clones belonged to the Acidobacterium (51%) and Planctomyces (18%) divisions. Agar plate counts of soil suspensions cultured on dilute yeast extract and R2A agar media incubated at 25 or 50 degrees C revealed that thermophile populations were two to three orders of magnitude greater in the recently heated soil. A soil microcosm laboratory experiment simulated the geothermal heating event. As determined by both RNA- and DNA-based PCR coupled with DGGE, changes in community structure (marked change in the DGGE profile) of soils incubated at 50 degrees C occurred within 1 week and appeared to stabilize after 3 weeks. The results of our molecular and culture data suggest that thermophiles or thermotolerant species are randomly distributed in this area within Yellowstone National Park and that localized thermal activity selects for them.

Low-melting point heat transfer fluid

Science.gov (United States)

Cordaro, Joseph Gabriel; Bradshaw, Robert W.

2010-11-09

A low-melting point, heat transfer fluid made of a mixture of five inorganic salts including about 29.1-33.5 mol % LiNO.sub.3, 0-3.9 mol % NaNO.sub.3, 2.4-8.2 mol % KNO.sub.3, 18.6-19.9 mol % NaNO.sub.2, and 40-45.6 mol % KNO.sub.2. These compositions can have liquidus temperatures below 80.degree. C. for some compositions.

Self-adjusting house-heating control system

Energy Technology Data Exchange (ETDEWEB)

Hacker, O; Ott, M

1983-01-01

Only small expenditure in terms of hard- and software is needed for the heating-control system described here to keep the house-room temperature in day- and night (reduced temperature)-operation precisely at the desired degree C. No control adjustment is needed as the computer - in this case an EMUF-model - adapts itself to changing conditions like type of house, weather conditions etc. Perfect control and good control dynamic lead to considerable savings of energy.

The effect of ethylenediaminetetraacetic acid on heat resistance and recovery of Clostridium sporogenes PA 3679 spores treated in HTST conditions.

Science.gov (United States)

Silla Santos, M H; Torres Zarzo, J

1997-03-03

The effect of ethylenediaminetetraacetic acid (EDTA) on the heat resistance of Clostridium sporogenes PA 3679 spores was studied. EDTA was added to heating substrates and recovery media in order to establish which stage of the heat treatment registered the greatest EDTA activity. The heating substrates assayed were phosphate buffer (pH 7.0) and white asparagus purée, at natural pH (5.8) and acidified with citric acid and glucono-delta-lactone (GDL) to pH 5.5, 5.0 and 4.5. Recovery of survivors was carried out in MPA3679A medium in various conditions of acidification with citric and GDL (250 and 500 ppm), at pH 7.5 6.5 and 6.0. The results show greater activity of EDTA on spores when it was applied in recovery of heat injured spores, than during heating. The strongest influence of EDTA during heating was found in phosphate buffer (pH 7.0), with the effect being most evident at 121 and 126 degrees C, and in asparagus purée, at 121 degrees C and pH 5.8 rather than acidified. In recovery, the inhibiting activity of EDTA was more evident in spores subjected to more severe heat treatment, either by increasing the exposure time or by raising the temperature to 130 or 135 degrees C. The pH level of the recovery medium also affected the antimicrobial activity of EDTA, which had a greater inhibiting effect at pH 7.5 than at lower pH levels (6.5, 6.0).

Heat pipe heat exchangers in heat recovery systems

Energy Technology Data Exchange (ETDEWEB)

Stulc, P; Vasiliev, L L; Kiseljev, V G; Matvejev, Ju N

1985-01-01

The results of combined research and development activities of the National Research Institute for Machine Design, Prague, C.S.S.R. and the Institute for Heat and Mass Transfer, Minsk, U.S.S.R. concerning intensification heat pipes used in heat pipe heat exchangers are presented. This sort of research has been occasioned by increased interest in heat power economy trying to utilise waste heat produced by various technological processes. The developed heat pipes are deployed in construction of air-air, gas-air or gas-gas heat recovery exchangers in the field of air-engineering and air-conditioning. (author).

Critical heat fluxes in tubular fuel elements of nuclear power reactors

International Nuclear Information System (INIS)

Subbotin, V.I.; Alekseev, G.V.; Peskov, O.L.

1974-01-01

The results of the experiments carried out show that with appropriate choice of tube, type and dimensions of intensifier the attainment of critical conditions at certain parameters is not accompanied by sharp or considerable increases in temperature of the heat removing surface. Increase in power to above critical under these conditions does not lead to considerable variation in temperature either. Thus, it appears possible to change from heat removal by steam-water mixture to convective heat removal by wet steam without manifestation of intolerable temperature conditions of the heating surface (Fig. 6). A change to convective heat removal by wet steam is possible at different levels of heat fluxes which depend during constant conditions at the inlet on tube length and the degree of the disturbing influence on the flow. This is especially important since in principle the possibility arises for developing a power reactor with tubular fuel elements, in which a once-through cycle with steam superheat involving no intermediate separation can be realised

Degree distribution in discrete case

International Nuclear Information System (INIS)

Wang, Li-Na; Chen, Bin; Yan, Zai-Zai

2011-01-01

Vertex degree of many network models and real-life networks is limited to non-negative integer. By means of measure and integral, the relation of the degree distribution and the cumulative degree distribution in discrete case is analyzed. The degree distribution, obtained by the differential of its cumulative, is only suitable for continuous case or discrete case with constant degree change. When degree change is not a constant but proportional to degree itself, power-law degree distribution and its cumulative have the same exponent and the mean value is finite for power-law exponent greater than 1. -- Highlights: → Degree change is the crux for using the cumulative degree distribution method. → It suits for discrete case with constant degree change. → If degree change is proportional to degree, power-law degree distribution and its cumulative have the same exponent. → In addition, the mean value is finite for power-law exponent greater than 1.

Experimental investigation of water sprayed finned heat exchanger tube bundles

International Nuclear Information System (INIS)

Sommer, A.

1987-07-01

Experimental investigations have been made to study the performance of two finned tube-bundle heat exchangers (FORGO type) when wetted by water sprays. The heat exchangers are designed to cool water in a dry cooling tower. The test-elements had a frontal area of 1 m 2 . The water sprays were created by 20 nozzles, 200 mm in front of the heat exchangers. Air velocities at the inlet of the coolers were in the range 0,8 m/s to 12 m/s and initial temperature differences ITD reached 45 degrees C. The test facility was designed to determine the combined latent and sensible heat fluxes in the wetted heat exchanger, the airside pressure drop and the air humidity and temperature at the exchanger inlet and outlet, and to measure the weight of the water wetting the cooler's surface. The sprayed test elements were investigated in different positions, but most of the experiments were carried out in the position with the fins horizontal

Quantitative Global Heat Transfer in a Mach-6 Quiet Tunnel

Science.gov (United States)

Sullivan, John P.; Schneider, Steven P.; Liu, Tianshu; Rubal, Justin; Ward, Chris; Dussling, Joseph; Rice, Cody; Foley, Ryan; Cai, Zeimin; Wang, Bo;

Heat integration and analysis of decarbonised IGCC sites

Energy Technology Data Exchange (ETDEWEB)

Ng, K.S.; Lopez, Y.; Campbell, G.M.; Sadhukhan, J. [University of Manchester, Manchester (United Kingdom). School of Chemical Engineering & Analytical Science

2010-02-15

Integrated gasification combined cycle (IGCC) power generation systems have become of interest due to their high combined heat and power (CHP) generation efficiency and flexibility to include carbon capture and storage (CCS) in order to reduce CO{sub 2} emissions. However, IGCC's biggest challenge is its high cost of energy production. In this study, decarbonised coal IGCC sites integrated with CCS have been investigated for heat integration and economic value analyses. It is envisaged that the high energy production cost of an IGCC site can be offset by maximising site-wide heat recovery and thereby improving the cost of electricity (COE) of CHP generation. Strategies for designing high efficiency CHP networks have been proposed based on thermodynamic heuristics and pinch theory. Additionally, a comprehensive methodology to determine the COE from a process site has been developed. In this work, we have established thermodynamic and economic comparisons between IGCC sites with and without CCS and a trade-off between the degree of decarbonisation and the COE from the heat integrated IGCC sites. The results show that the COE from the heat integrated decarbonised IGCC sites is significantly lower compared to IGCC sites without heat integration making application of CCS in IGCC sites economically competitive.