WorldWideScience

Sample records for acceptable thermal conditions

  1. An energy performance assessment for indoor environmental quality (IEQ) acceptance in air-conditioned offices

    International Nuclear Information System (INIS)

    Wong, L.T.; Mui, K.W.

    2009-01-01

    Maintaining an acceptable indoor environmental quality (IEQ) for air-conditioned office buildings consumes a considerable amount of thermal energy. This study correlates thermal energy consumption with the overall occupant acceptance of IEQ in some air-conditioned offices. An empirical expression of an IEQ index associated with thermal comfort, indoor air quality, aural and visual comfort is used to benchmark the offices. Employing input parameters obtained from the building stocks of Hong Kong, the office portfolios regarding the thermal energy consumption and the IEQ index are determined by Monte Carlo simulations. In particular, an energy-to-acceptance ratio and an energy-to-IEQ improvement ratio are proposed to measure the performance of energy consumption for the IEQ in the air-conditioned offices. The ratios give the thermal energy consumption corresponding to a desirable percentage of IEQ acceptances and to an IEQ upgrade, respectively. The results showed a non-linear increasing trend of annual thermal energy consumption for IEQ improvement at the offices of higher IEQ benchmarks. The thermal energy consumption for visual comfort and indoor air quality would also be significant in these offices. This study provides useful information that incorporates the IEQ in air-conditioned offices into the development of performance evaluation measures for thermal energy consumption.

  2. Preliminary study on acceptability of scope of thermal discharge mixing zone for nuclear power plant

    International Nuclear Information System (INIS)

    Liu Yongye; Yang Yang; Wang Liang; Chen Xiaoqiu; Liu Senlin

    2012-01-01

    Based on the situation that the existing domestic temperature control standards are not performable, the preliminary study on the acceptability of the mixing zone scope of thermal discharge for nuclear power plant was conducted in this paper, taking a coastal power station SNP as a case. The following preliminary conclusions could be drawn from the results of cluster analysis of the SNP site under different results of mathematical modeling and physical model test: 1) The influence intensity of ecological function of the SNP site seawater is small and the scope of thermal discharge mixing zone is acceptable under SNP-1 (Unit 1 and 2) operating condition; 2) the influence intensity of ecological function of the SNP site seawater is small and the scope of thermal discharge mixing zone is acceptable in spring under SNP-1 (Unit 1 and 2) and SNP-2 (Unit 3 and 4) operating condition, while the influence intensity of ecological function of the SNP site seawater is large and the scope of mixing zone is unacceptable in autumn under the same operating condition. (authors)

  3. Criteria for accepting piping thermal expansion movements during FFTF plant startup

    International Nuclear Information System (INIS)

    Clark, G.L.; Anderson, M.J.

    1981-03-01

    A deflection measurement program was conducted as a final step in the design qualification of the Fast Flux Test Facility liquid sodium piping. Measurements were obtained from the ambient empty position, through the 400 0 F (204 0 C) sodium fill, to an 800 0 F (427 0 C) maximum iso-thermal test condition. The program was designed to confirm that the pipe responded as predicted under both deadweight and thermal expansion loads. This paper describes the design of the test programs; the criteria used to select appropriate measurement locations from the approximately 4000 supports used on this pipe; and the criteria used to accept test results

  4. 12 CFR 412.7 - Conditions for acceptance.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Conditions for acceptance. 412.7 Section 412.7 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES ACCEPTANCE OF PAYMENT FROM A NON-FEDERAL SOURCE FOR TRAVEL EXPENSES § 412.7 Conditions for acceptance. (a) Eximbank may accept payment for...

  5. THERMAL COMFORT STUDY OF AN AIR-CONDITIONED DESIGN STUDIO IN TROPICAL SURABAYA

    Directory of Open Access Journals (Sweden)

    Agus Dwi Hariyanto

    2005-01-01

    Full Text Available This paper evaluates the current thermal comfort condition in an air-conditioned design studio using objective measurement and subjective assessment. Objective measurement is mainly to quantify the air temperature, MRT, relative humidity, and air velocity. Subjective assessment is conducted using a questionnaire to determine the occupants thermal comfort sensations and investigate their perception of the thermal comfort level. A design studio in an academic institution in Surabaya was chosen for the study. Results show that more than 80% of the occupants accepted the indoor thermal conditions even though both the environmental and comfort indices exceeded the limit of the standard (ASHRAE Standard 55 and ISO 7730. In addition, non-uniformity of spatial temperature was present in this studio. Some practical recommendations were made to improve the thermal comfort in the design studio.

  6. Occupant performance and building energy consumption with different philosophies of determining acceptable thermal conditions

    DEFF Research Database (Denmark)

    Toftum, Jørn; Andersen, Rune Vinther; Jensen, Kasper Lynge

    2009-01-01

    Based on building energy and indoor environment simulations, this study uses a recently developed method relying on Bayesian Network theory to estimate and compare the consequences for occupant performance and energy consumption of applying temperature criteria set according to the adaptive model...... configurations, especially in the tropical climate, the estimated performance differed only modestly between configurations. However, energy consumption was always lower in buildings without mechanical cooling, particularly so in the tropical climate. The findings indicate that determining acceptable indoor...... thermal environments with the adaptive comfort model may result in significant energy savings and at the same time will not have large consequences for the mental performance of occupants....

  7. Acceptance conditions in automated negotiation

    NARCIS (Netherlands)

    Baarslag, T.; Hindriks, K.V.; Jonker, C.M.

    2011-01-01

    In every negotiation with a deadline, one of the negotiating parties has to accept an offer to avoid a break off. A break off is usually an undesirable outcome for both parties, therefore it is important that a negotiator employs a proficient mechanism to decide under which conditions to accept.

  8. Assessment of monitored energy use and thermal comfort conditions in mosques in hot-humid climates

    Energy Technology Data Exchange (ETDEWEB)

    Al-Homoud, Mohammad S.; Abdou, Adel A.; Budaiwi, Ismail M. [Architectural Engineering Department, KFUPM, Dhahran 31261 (Saudi Arabia)

    2009-06-15

    In harsh climatic regions, buildings require air-conditioning in order to provide an acceptable level of thermal comfort. In many situations buildings are over cooled or the HVAC system is kept running for a much longer time than needed. In some other situations thermal comfort is not achieved due to improper operation practices coupled with poor maintenance and even lack it, and consequently inefficient air-conditioning systems. Mosques represent one type of building that is characterized by their unique intermittent operating schedule determined by prayer times, which vary continuously according to the local solar time. This paper presents the results of a study designed to monitor energy use and thermal comfort conditions of a number of mosques in a hot-humid climate so that both energy efficiency and the quality of thermal comfort conditions especially during occupancy periods in such intermittently operated buildings can be assessed accurately. (author)

  9. Thermal sensations and comfort investigations in transient conditions in tropical office.

    Science.gov (United States)

    Dahlan, Nur Dalilah; Gital, Yakubu Yau

    2016-05-01

    The study was done to identify affective and sensory responses observed as a result of hysteresis effects in transient thermal conditions consisting of warm-neutral and neutral - warm performed in a quasi-experiment setting. Air-conditioned building interiors in hot-humid areas have resulted in thermal discomfort and health risks for people moving into and out of buildings. Reports have shown that the instantaneous change in air temperature can cause abrupt thermoregulation responses. Thermal sensation vote (TSV) and thermal comfort vote (TCV) assessments as a consequence of moving through spaces with distinct thermal conditions were conducted in an existing single-story office in a hot-humid microclimate, maintained at an air temperature 24 °C (± 0.5), relative humidity 51% (± 7), air velocity 0.5 m/s (± 0.5), and mean radiant temperature (MRT) 26.6 °C (± 1.2). The measured office is connected to a veranda that showed the following semi-outdoor temperatures: air temperature 35 °C (± 2.1), relative humidity 43% (± 7), air velocity 0.4 m/s (± 0.4), and MRT 36.4 °C (± 2.9). Subjective assessments from 36 college-aged participants consisting of thermal sensations, preferences and comfort votes were correlated against a steady state predicted mean vote (PMV) model. Local skin temperatures on the forehead and dorsal left hand were included to observe physiological responses due to thermal transition. TSV for veranda-office transition showed that no significant means difference with TSV office-veranda transition were found. However, TCV collected from warm-neutral (-0.24, ± 1.2) and neutral-warm (-0.72, ± 1.3) conditions revealed statistically significant mean differences (p thermal transition after travel from warm-neutral-warm conditions did not replicate the hysteresis effects of brief, slightly cool, thermal sensations found in previous laboratory experiments. These findings also indicate that PMV is an acceptable alternative to predict thermal

  10. Evaluating Thermal Comfort in a Naturally Conditioned Office in a Temperate Climate Zone

    Directory of Open Access Journals (Sweden)

    Andrés Gallardo

    2016-07-01

    Full Text Available This study aims to determine the optimal approach for evaluating thermal comfort in an office that uses natural ventilation as the main conditioning strategy; the office is located in Quito-Ecuador. The performance of the adaptive model included in CEN Standard EN15251 and the traditional PMV model are compared with reports of thermal environment satisfaction surveys presented simultaneously to all occupants of the office to determine which of the two comfort models is most suitable to evaluate the thermal environment. The results indicate that office occupants have developed some degree of adaptation to the climatic conditions of the city where the office is located (which only demands heating operation, and tend to accept and even prefer lower operative temperatures than those considered optimum by applying the PMV model. This is an indication that occupants of naturally conditioned buildings are usually able to match their comfort temperature to their normal environment. Therefore, the application of the adaptive model included in CEN Standard EN15251 seems like the optimal approach for evaluating thermal comfort in naturally conditioned buildings, because it takes into consideration the adaptive principle that indicates that if a change occurs such as to produce discomfort, people tend to react in ways which restore their comfort.

  11. Conditions for acceptance and usage of mobile payment procedures

    OpenAIRE

    Pousttchi, Key

    2003-01-01

    Mobile payment (MP) is crucial for, but not limited to mobile commerce. The key to mobile payment acceptance is in the hands of customers. In this paper we examine the conditions for acceptance and actual usage of MP procedures by the customer. We identify essential conditions which belong to the categories costs, security and convenience. Different preferences lead to an individual set of essential conditions for any single user. We propose a scheme for their representation and comparison an...

  12. An energy impact assessment of indoor air quality acceptance for air-conditioned offices

    International Nuclear Information System (INIS)

    Wong, L.T.; Mui, K.W.; Shi, K.L.; Hui, P.S.

    2008-01-01

    Treatment of fresh air in ventilation systems for the air-conditioning consumes a considerable amount of energy and affects the indoor air quality (IAQ). The ventilation demand is primarily related to the occupant load. In this study, the ventilation demands due to occupant load variations and occupant acceptability were examined against certain IAQ objectives using the mass balance of carbon dioxide (CO 2 ) concentrations in an air-conditioned office. In particular, this study proposed a ventilation model for the consideration of the occupant load variations and occupant acceptability based on the regional survey of typical offices (422 samples) in Hong Kong. The model was applied to evaluate the relative energy performance of different IAQ objectives in ventilation systems for typical office buildings in Hong Kong. The results showed that the energy consumption of a ventilation system would be correlated with the occupant load and acceptability in the air-conditioned office. Indicative CO 2 levels of 800 ppmv, 1000 ppmv and 1200 ppmv corresponding to 83%, 97% and 99.7% survey samples were shown, corresponding to the thermal energy consumptions of 1500 MJ m -2 yr -1 , 960 MJ m -2 yr -1 and 670 MJ m -2 yr -1 , respectively. In regards to the monetary issue, an annual value of HK$ 762 million per year in electrical consumption could be saved in all office buildings in Hong Kong when the indoor target CO 2 concentration is increased from 1000 ppmv to 1200 ppmv. To achieve an excellent IAQ following the existing design standard, i.e. to decrease the CO 2 level from 1000 ppmv to 800 ppmv, 56% additional energy would be consumed, corresponding to an annual value of HK$ 1,419 million, even though the occupant acceptability is only improved from 81% to 86%. The development of the models in this study would be useful for the energy performance evaluation of ventilation systems in air-conditioned offices

  13. Dark chocolate acceptability: influence of cocoa origin and processing conditions.

    Science.gov (United States)

    Torres-Moreno, Miriam; Tarrega, Amparo; Costell, Elvira; Blanch, Consol

    2012-01-30

    Chocolate properties can vary depending on cocoa origin, composition and manufacturing procedure, which affect consumer acceptability. The aim of this work was to study the effect of two cocoa origins (Ghana and Ecuador) and two processing conditions (roasting time and conching time) on dark chocolate acceptability. Overall acceptability and acceptability for different attributes (colour, flavour, odour and texture) were evaluated by 95 consumers. Differences in acceptability among dark chocolates were mainly related to differences in flavour acceptability. The use of a long roasting time lowered chocolate acceptability in Ghanaian samples while it had no effect on acceptability of Ecuadorian chocolates. This response was observed for most consumers (two subgroups with different frequency consumption of dark chocolate). However, for a third group of consumers identified as distinguishers, the most acceptable dark chocolate samples were those produced with specific combinations of roasting time and conching time for each of the cocoa geographical origin considered. To produce dark chocolates from a single origin it is important to know the target market preferences and to select the appropriate roasting and conching conditions. Copyright © 2011 Society of Chemical Industry.

  14. A quantitative sensitivity analysis on the behaviour of common thermal indices under hot and windy conditions in Doha, Qatar

    Science.gov (United States)

    Fröhlich, Dominik; Matzarakis, Andreas

    2016-04-01

    Human thermal perception is best described through thermal indices. The most popular thermal indices applied in human bioclimatology are the perceived temperature (PT), the Universal Thermal Climate Index (UTCI), and the physiologically equivalent temperature (PET). They are analysed focusing on their sensitivity to single meteorological input parameters under the hot and windy meteorological conditions observed in Doha, Qatar. It can be noted, that the results for the three indices are distributed quite differently. Furthermore, they respond quite differently to modifications in the input conditions. All of them show particular limitations and shortcomings that have to be considered and discussed. While the results for PT are unevenly distributed, UTCI shows limitations concerning the input data accepted. PET seems to respond insufficiently to changes in vapour pressure. The indices should therefore be improved to be valid for several kinds of climates.

  15. Quaternion Based Thermal Condition Monitoring System

    Science.gov (United States)

    Wong, Wai Kit; Loo, Chu Kiong; Lim, Way Soong; Tan, Poi Ngee

    In this paper, we will propose a new and effective machine condition monitoring system using log-polar mapper, quaternion based thermal image correlator and max-product fuzzy neural network classifier. Two classification characteristics namely: peak to sidelobe ratio (PSR) and real to complex ratio of the discrete quaternion correlation output (p-value) are applied in the proposed machine condition monitoring system. Large PSR and p-value observe in a good match among correlation of the input thermal image with a particular reference image, while small PSR and p-value observe in a bad/not match among correlation of the input thermal image with a particular reference image. In simulation, we also discover that log-polar mapping actually help solving rotation and scaling invariant problems in quaternion based thermal image correlation. Beside that, log-polar mapping can have a two fold of data compression capability. Log-polar mapping can help smoother up the output correlation plane too, hence makes a better measurement way for PSR and p-values. Simulation results also show that the proposed system is an efficient machine condition monitoring system with accuracy more than 98%.

  16. Rapid thermal conditioning of sewage sludge

    Science.gov (United States)

    Zheng, Jianhong

    Rapid thermal conditioning (RTC) is a developing technology recently applied to sewage sludge treatment. Sludge is heated rapidly to a reaction temperature (up to about 220sp°C) under sufficient pressure to maintain the liquid phase. Reaction is quenched after 10 to 30 seconds when the mixture of sludge and steam pass through a pressure let-down valve. This process reduces the amount of sludge requiring land disposal, eliminates the need for polymer coagulant, improves dewaterability, increases methane production, and further reduces the concentration of pathogens. The odor problem associated with traditional thermal conditioning processes is largely minimized. Ammonia removal is readily integrated with the process. For this research, a pilot unit was constructed capable of processing 90 liters of sludge per hour. Over 22 runs were made with this unit using sludge from New York City Water Pollution Control Plants (WPCP). Sludges processed in this equipment were tested to determine the effect of RTC operating conditions on sludge dewaterability, biodegradability, and other factors affecting the incorporation of RTC into wastewater treatment plants. Dewaterability of thermally conditioned sludge was assessed for cetrifugeability and filterability. Bench scale centrifugation was used for evaluating centrifugeability, pressure filtration and capillary suction time (CST) for filterability. A mathematical model developed for centrifuge dewatering was used to predict the effect of RTC on full scale centrifuge performance. Particle size distribution and solids density of raw and treated PDS were also analyzed. An observed increase in sludge solids density at least partially explains its improved centrifugeability. An investigation of thermally conditioned amino acids showed that the L-isomer is highly biodegradable while the D-isomers are generally less so. Glucose is highly biodegradable, but rapidly becomes refractory as thermal conditioning time is lengthened. This

  17. Acceptance of Conditional Suicide and Euthanasia among Adult Americans.

    Science.gov (United States)

    Johnson, David; And Others

    1980-01-01

    Analysis indicates that religious intensity, sex, age, and education are important associational variables regarding attitudes toward suicide and euthanasia. Males are more accepting than females. Females are influenced by family life conditions. Males are influenced by health status. (JMF)

  18. Dynamic thermal environment and thermal comfort.

    Science.gov (United States)

    Zhu, Y; Ouyang, Q; Cao, B; Zhou, X; Yu, J

    2016-02-01

    Research has shown that a stable thermal environment with tight temperature control cannot bring occupants more thermal comfort. Instead, such an environment will incur higher energy costs and produce greater CO2 emissions. Furthermore, this may lead to the degeneration of occupants' inherent ability to combat thermal stress, thereby weakening thermal adaptability. Measured data from many field investigations have shown that the human body has a higher acceptance to the thermal environment in free-running buildings than to that in air-conditioned buildings with similar average parameters. In naturally ventilated environments, occupants have reported superior thermal comfort votes and much greater thermal comfort temperature ranges compared to air-conditioned environments. This phenomenon is an integral part of the adaptive thermal comfort model. In addition, climate chamber experiments have proven that people prefer natural wind to mechanical wind in warm conditions; in other words, dynamic airflow can provide a superior cooling effect. However, these findings also indicate that significant questions related to thermal comfort remain unanswered. For example, what is the cause of these phenomena? How we can build a comfortable and healthy indoor environment for human beings? This article summarizes a series of research achievements in recent decades, tries to address some of these unanswered questions, and attempts to summarize certain problems for future research. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. 50 CFR 84.40 - What conditions must I follow to accept Federal grant money?

    Science.gov (United States)

    2010-10-01

    ... Federal grant money? 84.40 Section 84.40 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE... COASTAL WETLANDS CONSERVATION GRANT PROGRAM Conditions on Acceptance/Use of Federal Money § 84.40 What conditions must I follow to accept Federal grant money? (a) The audit requirements for State and local...

  20. A Lumped Thermal Model Including Thermal Coupling and Thermal Boundary Conditions for High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2018-01-01

    Detailed thermal dynamics of high power IGBT modules are important information for the reliability analysis and thermal design of power electronic systems. However, the existing thermal models have their limits to correctly predict these complicated thermal behavior in the IGBTs: The typically used...... thermal model based on one-dimensional RC lumps have limits to provide temperature distributions inside the device, moreover some variable factors in the real-field applications like the cooling and heating conditions of the converter cannot be adapted. On the other hand, the more advanced three......-dimensional thermal models based on Finite Element Method (FEM) need massive computations, which make the long-term thermal dynamics difficult to calculate. In this paper, a new lumped three-dimensional thermal model is proposed, which can be easily characterized from FEM simulations and can acquire the critical...

  1. Spent fuel transport cask thermal evaluation under normal and accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, G. [Department of Mechanical, Nuclear and Production Engineering, University of Pisa, Via Diotisalvi, no 2-56126 Pisa (Italy); Lo Frano, R., E-mail: rosa.lofrano@ing.unipi.i [Department of Mechanical, Nuclear and Production Engineering, University of Pisa, Via Diotisalvi, no 2-56126 Pisa (Italy); Forasassi, G. [Department of Mechanical, Nuclear and Production Engineering, University of Pisa, Via Diotisalvi, no 2-56126 Pisa (Italy)

    2010-06-15

    The casks used for transport of nuclear materials, especially the spent fuel element (SPE), must be designed according to rigorous acceptance criteria and standards requirements, e.g. the International Atomic Energy Agency ones, in order to provide protection to people and environment against radiation exposure particularly in a severe accident scenario. The aim of this work was the evaluation of the integrity of a spent fuel cask under both normal and accident scenarios transport conditions, such as impact and rigorous fire events, in according to the IAEA accident test requirements. The thermal behaviour and the temperatures distribution of a Light Water Reactor (LWR) spent fuel transport cask are presented in this paper, especially with reference to the Italian cask designed by AGN, which was characterized by a cylindrical body, with water or air inside the internal cavity, and two lateral shock absorbers. Using the finite element code ANSYS a series of thermal analyses (steady-state and transient thermal analyses) were carried out in order to obtain the maximum fuel temperature and the temperatures field in the body of the cask, both in normal and in accidents scenario, considering all the heat transfer modes between the cask and the external environment (fire in the test or air in the normal conditions) as well as inside the cask itself. In order to follow the standards requirements, the thermal analyses in accidents scenarios were also performed adopting a deformed shape of the shock absorbers to simulate the mechanical effects of a previous IAEA 9 m drop test event. Impact tests on scale models of the shock absorbers have already been conducted in the past at the Department of Mechanical, Nuclear and Production Engineering, University of Pisa, in the '80s. The obtained results, used for possible new licensing approval purposes by the Italian competent Authority of the cask for PWR spent fuel cask transport by the Italian competent Authority, are

  2. Thermal history and comfort in a Brazilian subtropical climate: a 'cool' addiction hypothesis

    Directory of Open Access Journals (Sweden)

    Renata De Vecchi

    Full Text Available Abstract Currently, there is a rising trend for commercial buildings to use air conditioning to provide indoor thermal comfort. This paper focuses on the impact of prolonged exposure to indoor air-conditioned environments on occupants' thermal acceptability and preferences in a mixed-mode building in Brazil. Questionnaires were administered while indoor microclimatic measurements were carried out (i.e., air temperature, radiant air temperature, air speed and humidity. Results suggest significant differences in occupants' thermal acceptability and cooling preferences based on thermal history; differences were found between groups based on different physical characteristics (i.e., different gender and body condition. The findings also indicated a significant potential to implement temperature fluctuations indoors when occupants are exposed to air conditioning environments in warm and humid climates.

  3. Public acceptance of drug use for non-disease conditions

    DEFF Research Database (Denmark)

    Møldrup, Claus; Hansen, Rikke Rie

    2006-01-01

    OBJECTIVE: This article deals with the issue of ordinary healthy people using drugs to improve or enhance non-disease conditions. The objective is to illuminate the extent of public acceptance of this practice. RESEARCH DESIGN AND METHODS: The results are based on two studies: a classically...... of drugs for non-disease conditions. Men in particular look favourably on the use of drugs by healthy individuals. People with less education find this type of drug use unacceptable to a greater extent than those with more education, who are more positive. If we look at political affiliation, a pattern...

  4. ACCEPT: Introduction of the Adverse Condition and Critical Event Prediction Toolbox

    Science.gov (United States)

    Martin, Rodney A.; Santanu, Das; Janakiraman, Vijay Manikandan; Hosein, Stefan

    2015-01-01

    The prediction of anomalies or adverse events is a challenging task, and there are a variety of methods which can be used to address the problem. In this paper, we introduce a generic framework developed in MATLAB (sup registered mark) called ACCEPT (Adverse Condition and Critical Event Prediction Toolbox). ACCEPT is an architectural framework designed to compare and contrast the performance of a variety of machine learning and early warning algorithms, and tests the capability of these algorithms to robustly predict the onset of adverse events in any time-series data generating systems or processes.

  5. Simulation of global warming effect on outdoor thermal comfort conditions

    Energy Technology Data Exchange (ETDEWEB)

    Roshan, G.R.; Ranjbar, F. [Univ. of Tehran (IR). Dept. of Physical Geography; Orosa, J.A. [Univ. of A Coruna (Spain). Dept. of Energy

    2010-07-01

    In the coming decades, global warming and increase in temperature, in different regions of the world, may change indoor and outdoor thermal comfort conditions and human health. The aim of this research was to study the effects of global warming on thermal comfort conditions in indoor ambiences in Iran. To study the increase in temperature, model for assessment of greenhouse-gas induced climate change scenario generator compound model has been used together with four scenarios and to estimate thermal comfort conditions, adaptive model of the American Society of Heating, Refrigerating and Air-Conditioning Engineers has been used. In this study, Iran was divided into 30 zones, outdoor conditions were obtained using meteorological data of 80 climatological stations and changes in neutral comfort conditions in 2025, 2050, 2075 and 2100 were predicted. In accordance with each scenario, findings from this study showed that temperature in the 30 zones will increase by 2100 to between 3.4 C and 5.6 C. In the coming decades and in the 30 studied zones, neutral comfort temperature will increase and be higher and more intense in the central and desert zones of Iran. The low increase in this temperature will be connected to the coastal areas of the Caspian and Oman Sea in southeast Iran. This increase in temperature will be followed by a change in thermal comfort and indoor energy consumption from 8.6 % to 13.1 % in air conditioning systems. As a result, passive methods as thermal inertia are proposed as a possible solution.

  6. Assessment of thermal load on transported goats administered with ascorbic acid during the hot-dry conditions

    Science.gov (United States)

    Minka, N. S.; Ayo, J. O.

    2012-03-01

    The major factor in the induction of physiological stress during road transportation of livestock is the complex fluctuations of the thermal transport microenvironment, encountered when animals are transported across different ecological zones. Recommended guidelines on optimum "on-board" conditions in which goats should be transported are lacking, and there are no acceptable ranges and limits for the thermal loads to which goats may be subjected during long-distance road transportation in hot-dry conditions. Panting score (PS), rectal temperature (RT), heart rate (HR) and respiratory rate (RR) were employed as reliable stress indices to assess the effects of different thermal loads, measured as temperature humidity index (THI), encountered in the vehicle during 12 h of road transportation of 40 goats, and to suggest the administration of 100 mg/kg body weight of ascorbic acid (AA) as an ameliorating agent. The results obtained showed that the PS, RT, HR and RR rose above normal reference values with increase in the THI and journey duration. The rise in PS value, which is a visual indicator of the severity of thermal load, was the most pronounced. The results suggest that values of THI in the vehicle up to 94.6 constitute no risk, while at of 100 it presents a moderate risk and above 100 may result in severe stress. The relationships between the thermal load and the physiological variables were positive and significant ( P goats. The results demonstrated that administration of 100 mg/kg body weight of AA before road transportation mitigated the risk of adverse effects of high THI values and other stress factors due to road transportation in goats.

  7. A thermal model for photovoltaic panels under varying atmospheric conditions

    International Nuclear Information System (INIS)

    Armstrong, S.; Hurley, W.G.

    2010-01-01

    The response of the photovoltaic (PV) panel temperature is dynamic with respect to the changes in the incoming solar radiation. During periods of rapidly changing conditions, a steady state model of the operating temperature cannot be justified because the response time of the PV panel temperature becomes significant due to its large thermal mass. Therefore, it is of interest to determine the thermal response time of the PV panel. Previous attempts to determine the thermal response time have used indoor measurements, controlling the wind flow over the surface of the panel with fans or conducting the experiments in darkness to avoid radiative heat loss effects. In real operating conditions, the effective PV panel temperature is subjected to randomly varying ambient temperature and fluctuating wind speeds and directions; parameters that are not replicated in controlled, indoor experiments. A new thermal model is proposed that incorporates atmospheric conditions; effects of PV panel material composition and mounting structure. Experimental results are presented which verify the thermal behaviour of a photovoltaic panel for low to strong winds.

  8. The effect of acceptance training on psychological and physical health outcomes in elders with chronic conditions.

    Science.gov (United States)

    McDonald, Patricia E; Zauszniewski, Jaclene A; Bekhet, Abir K; DeHelian, Laura; Morris, Diana L

    2011-12-01

    This pilot trial investigated the short and long-term effects of Acceptance Training (ACT) intervention on acceptance, perceived health, functional status, anxiety, and depression in elders with chronic conditions living in retirement communities (RCs). The ACT intervention combined Rational Emotive Behavior Therapy with music, relaxation, and guided imagery during six weekly 2-hour sessions. Face-to-face interviews were conducted with 16 African-American and 46 White elders across four data collection points in six randomly selected RCs using well-established measures of perceived health, functional status, anxiety, and depression, and a measure of acceptance of chronic conditions adapted from a previous measure of acceptance of diabetes. While changes were found in perceived health, functional status, anxiety, and depression, the most significant changes occurred in the elders' acceptance of chronic conditions immediately after the intervention (t = -2.62, p < .02), and these changes persisted for 6 and 12 weeks (t's = -2.74, -3.32, p's < .01), respectively. Although a 40% attrition rate reduced the sample size from 62 (N = 62) to 37 (N = 37), the significant increases in acceptance over time provide initial evidence for the fidelity of the ACT intervention.

  9. Monitoring Thermal Conditions in Footwear

    Science.gov (United States)

    Silva-Moreno, Alejandra. A.; Lopez Vela, Martín; Alcalá Ochoa, Noe

    2006-09-01

    Thermal conditions inside the foot were evaluated on a volunteer subject. We have designed and constructed an electronic system which can monitors temperature and humidity of the foot inside the shoe. The data is stored in a battery-powered device for later uploading to a host computer for data analysis. The apparatus potentially can be used to provide feedback to patients who are prone to having skin breakdowns.

  10. Thermal comfort of people in the hot and humid area of China-impacts of season, climate, and thermal history.

    Science.gov (United States)

    Zhang, Y; Chen, H; Wang, J; Meng, Q

    2016-10-01

    We conducted a climate chamber study on the thermal comfort of people in the hot and humid area of China. Sixty subjects from naturally ventilated buildings and buildings with split air conditioners participated in the study, and identical experiments were conducted in a climate chamber in both summer and winter. Psychological and physiological responses were observed over a wide range of conditions, and the impacts of season, climate, and thermal history on human thermal comfort were analyzed. Seasonal and climatic heat acclimatization was confirmed, but they were found to have no significant impacts on human thermal sensation and comfort. The outdoor thermal history was much less important than the indoor thermal history in regard to human thermal sensation, and the indoor thermal history in all seasons of a year played a key role in shaping the subjects' sensations in a wide range of thermal conditions. A warmer indoor thermal history in warm seasons produced a higher neutral temperature, a lower thermal sensitivity, and lower thermal sensations in warm conditions. The comfort and acceptable conditions were identified for people in the hot and humid area of China. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Thermal Analysis for Condition Monitoring of Machine Tool Spindles

    International Nuclear Information System (INIS)

    Clough, D; Fletcher, S; Longstaff, A P; Willoughby, P

    2012-01-01

    Decreasing tolerances on parts manufactured, or inspected, on machine tools increases the requirement to have a greater understanding of machine tool capabilities, error sources and factors affecting asset availability. Continuous usage of a machine tool during production processes causes heat generation typically at the moving elements, resulting in distortion of the machine structure. These effects, known as thermal errors, can contribute a significant percentage of the total error in a machine tool. There are a number of design solutions available to the machine tool builder to reduce thermal error including, liquid cooling systems, low thermal expansion materials and symmetric machine tool structures. However, these can only reduce the error not eliminate it altogether. It is therefore advisable, particularly in the production of high value parts, for manufacturers to obtain a thermal profile of their machine, to ensure it is capable of producing in tolerance parts. This paper considers factors affecting practical implementation of condition monitoring of the thermal errors. In particular is the requirement to find links between temperature, which is easily measureable during production and the errors which are not. To this end, various methods of testing including the advantages of thermal images are shown. Results are presented from machines in typical manufacturing environments, which also highlight the value of condition monitoring using thermal analysis.

  12. Willingness-to-accept reductions in HIV risks: conditional economic incentives in Mexico

    Science.gov (United States)

    Galárraga, Omar; Sosa-Rubí, Sandra G.; Infante, César; Gertler, Paul J.; Bertozzi, Stefano M.

    2014-01-01

    The objective of this study was to measure willingness-to-accept (WTA) reductions in risks for HIV and other sexually transmitted infections (STI) using conditional economic incentives (CEI) among men who have sex with men (MSM), including male sex workers (MSW) in Mexico City. A survey experiment was conducted with 1,745 MSM and MSW (18-25 years of age) who received incentive offers to decide first whether to accept monthly prevention talks and STI testing; and then a second set of offers to accept to stay free of STIs (verified by quarterly biological testing). The survey used random-starting-point and iterative offers. WTA was estimated with a maximum likelihood double-bounded dichotomous choice model. The average acceptance probabilities were: 73.9% for the monthly model, and 80.4% for the quarterly model. The incentive-elasticity of participation in the monthly model was 0.222, and it was 0.515 in the quarterly model. For a combination program with monthly prevention talks, and staying free of curable STI, the implied WTA was USD$288 per person per year, but it was lower for MSW: USD$156 per person per year. Thus, some of the populations at highest risk of HIV infection (MSM & MSW) seem well disposed to participate in a CEI program for HIV and STI prevention in Mexico. The average willingness-to-accept estimate is within the range of feasible allocations for prevention in the local context. Given the potential impact, Mexico, a leader in conditional cash transfers for human development and poverty reduction, could extend that successful model for targeted HIV/STI prevention. PMID:23377757

  13. Effects of Thermal Annealing Conditions on Cupric Oxide Thin Film

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo Seon; Oh, Hee-bong; Ryu, Hyukhyun [Inje University, Gimhae (Korea, Republic of); Lee, Won-Jae [Dong-Eui University, Busan (Korea, Republic of)

    2015-07-15

    In this study, cupric oxide (CuO) thin films were grown on fluorine doped tin oxide(FTO) substrate by using spin coating method. We investigated the effects of thermal annealing temperature and thermal annealing duration on the morphological, structural, optical and photoelectrochemical properties of the CuO film. From the results, we could find that the morphologies, grain sizes, crystallinity and photoelectrochemical properties were dependent on the annealing conditions. As a result, the maximum photocurrent density of -1.47 mA/cm{sup 2} (vs. SCE) was obtained from the sample with the thermal annealing conditions of 500 ℃ and 40 min.

  14. Estimation of thermal sensation during varied air temperature conditions.

    Science.gov (United States)

    Katsuura, T; Tabuchi, R; Iwanaga, K; Harada, H; Kikuchi, Y

    1998-03-01

    Seven male students were exposed to four varied air temperature environments: hot (37 degrees C) to neutral (27 degrees C) (HN), neutral to hot (NH), cool (17 degrees C) to neutral (CN), and neutral to cool (NC). The air temperature was maintained at the first condition for 20 min, then was changed to the second condition after 15 min and was held there for 20 min. Each subject wore a T-shirt, briefs, trunks, and socks. Each sat on a chair and was continuously evaluated for thermal sensation, thermal comfort, and air velocity sensation. Some physiological and thermal parameters were also measured every 5 s during the experiment. The correlation between thermal sensation and skin temperature at 15 sites was found to be poor. The subjects felt much warmer during the rising phase of the air temperature (CN, NH) than during the descending phase (HN, NC) at a given mean skin temperature. However, thermal sensation at the same heat flux or at the same value of the difference between skin and air temperature (delta(Tsk - Ta)) was not so different among the four experimental conditions, and the correlation between thermal sensation and heat flux or delta(Tsk - Ta) was fairly good. The multiple regression equation of the thermal sensation (TS) on 15 sites of skin temperature (Tsk; degrees C) was calculated and the coefficient of determination (R*2) was found to be 0.656. Higher coefficients of determination were found in the equations of thermal sensation for the heat flux (H; kcal.m-2.h-1) at the right and left thighs of the subjects and on delta(Tsk - Ta) (degrees C) at 4 sites. They were as follows: TS = 2.04 - 0.016 Hright - 0.036 Hleft; R*2 = 0.717, TS = 1.649 + 0.013 delta(Tsk - Ta)UpperArm - 0.036 delta(Tsk - Ta)Chest - 0.223 delta(Tsk - Ta)Thigh-0.083 delta(Tsk - Ta)LowerLeg; R*2 = 0.752, respectively.

  15. The relationship between bioclimatic thermal stress and subjective thermal sensation in pedestrian spaces

    Science.gov (United States)

    Pearlmutter, David; Jiao, Dixin; Garb, Yaakov

    2014-12-01

    Outdoor thermal comfort has important implications for urban planning and energy consumption in the built environment. To better understand the relation of subjective thermal experience to bioclimatic thermal stress in such contexts, this study compares micrometeorological and perceptual data from urban spaces in the hot-arid Negev region of Israel. Pedestrians reported on their thermal sensation in these spaces, whereas radiation and convection-related data were used to compute the Index of Thermal Stress (ITS) and physiologically equivalent temperature (PET). The former is a straightforward characterization of energy exchanges between the human body and its surroundings, without any conversion to an "equivalent temperature." Although the relation of ITS to subjective thermal sensation has been analyzed in the past under controlled indoor conditions, this paper offers the first analysis of this relation in an outdoor setting. ITS alone can account for nearly 60 % of the variance in pedestrians' thermal sensation under outdoor conditions, somewhat more than PET. A series of regressions with individual contextual variables and ITS identified those factors which accounted for additional variance in thermal sensation, whereas multivariate analyses indicated the considerable predictive power ( R-square = 0.74) of models including multiple contextual variables in addition to ITS. Our findings indicate that pedestrians experiencing variable outdoor conditions have a greater tolerance for incremental changes in thermal stress than has been shown previously under controlled indoor conditions, with a tapering of responses at high values of ITS. However, the thresholds of ITS corresponding to thermal "neutrality" and thermal "acceptability" are quite consistent regardless of context.

  16. Thermal Conditions in a Simulated Office Environment with Convective and Radiant Cooling Systems

    DEFF Research Database (Denmark)

    Mustakallio, Panu; Bolashikov, Zhecho Dimitrov; Kostov, Kalin

    2013-01-01

    velocity and turbulent intensity were measured and draft rate levels calculated in the room. Manikin-based equivalent temperature (MBET) was determined by two thermal manikins to identify the impact of the local thermal conditions generated by the studied systems on occupants’ thermal comfort. The results......The thermal conditions in a two person office room were measured with four air conditioning systems: chilled beam (CB), chilled beam with radiant panel (CBR), chilled ceiling with ceiling installed mixing ventilation (CCMV) and four desk partition mounted local radiant cooling panels with mixing...

  17. THERMAL COMFORT STUDY OF AN AIR-CONDITIONED DESIGN STUDIO IN TROPICAL SURABAYA

    OpenAIRE

    Agus Dwi Hariyanto

    2005-01-01

    This paper evaluates the current thermal comfort condition in an air-conditioned design studio using objective measurement and subjective assessment. Objective measurement is mainly to quantify the air temperature, MRT, relative humidity, and air velocity. Subjective assessment is conducted using a questionnaire to determine the occupants thermal comfort sensations and investigate their perception of the thermal comfort level. A design studio in an academic institution in Surabaya was chosen ...

  18. Thermal and Energy Performance of Conditioned Building Due To Insulated Sloped Roof

    Science.gov (United States)

    Irwan, Suhandi Syiful; Ahmed, Azni Zain; Zakaria, Nor Zaini; Ibrahim, Norhati

    2010-07-01

    For low-rise buildings in equatorial region, the roof is exposed to solar radiation longer than other parts of the envelope. Roofs are to be designed to reject heat and moderate the thermal impact. These are determined by the design and construction of the roofing system. The pitch of roof and the properties of construction affect the heat gain into the attic and subsequently the indoor temperature of the living spaces underneath. This finally influences the thermal comfort conditions of naturally ventilated buildings and cooling load of conditioned buildings. This study investigated the effect of insulated sloping roof on thermal energy performance of the building. A whole-building thermal energy computer simulation tool, Integrated Environmental Solution (IES), was used for the modelling and analyses. A building model with dimension of 4.0 m × 4.0 m × 3.0 m was designed with insulated roof and conventional construction for other parts of the envelope. A 75 mm conductive insulation material with thermal conductivity (k-value) of 0.034 Wm-1K-1 was installed underneath the roof tiles. The building was modelled with roof pitch angles of 0° , 15°, 30°, 45°, 60° and simulated for the month of August in Malaysian climate conditions. The profile for attic temperature, indoor temperature and cooling load were downloaded and evaluated. The optimum roof pitch angle for best thermal performance and energy saving was identified. The results show the pitch angle of 0° is able to mitigate the thermal impact to provide the best thermal condition with optimum energy savings. The maximum temperature difference between insulated and non-insulted roof for attic (AtticA-B) and indoor condition (IndoorA-B) is +7.8 °C and 0.4 °C respectively with an average energy monthly savings of 3.9 %.

  19. 20 CFR 703.306 - Kinds of negotiable securities that may be deposited; conditions of deposit; acceptance of deposits.

    Science.gov (United States)

    2010-04-01

    ... the Act in the amount fixed by the Office under the regulations in this part shall deposit any... deposited; conditions of deposit; acceptance of deposits. 703.306 Section 703.306 Employees' Benefits... negotiable securities that may be deposited; conditions of deposit; acceptance of deposits. A self-insurer or...

  20. Effect of addition of thermally modified cowpea protein on sensory acceptability and textural properties of wheat bread and sponge cake.

    Science.gov (United States)

    Campbell, Lydia; Euston, Stephen R; Ahmed, Mohamed A

    2016-03-01

    This paper investigates the sensory acceptability and textural properties of leavened wheat bread and sponge cake fortified with cow protein isolates that had been denatured and glycated by thermal treatment. Defatted cowpea flour was prepared from cow pea beans and the protein isolate was prepared (CPI) and thermally denatured (DCPI). To prepare glycated cowpea protein isolate (GCPI) the cowpea flour slurry was heat treated before isolation of the protein. CPI was more susceptible to thermal denaturation than GCPI as determined by turbidity and sulphydryl groups resulting in greater loss of solubility. This is attributed to the higher glycation degree and higher carbohydrate content of GCPI as demonstrated by glycoprotein staining of SDS PAGE gels. Water absorption of bread dough was significantly enhanced by DCPI and to a larger extent GCPI compared to the control, resulting in softer texture. CPI resulted in significantly increased crumb hardness in baked bread than the control whereas DCPI or GCPI resulted in significantly softer crumb. Bread fortified with 4% DCPI or GCPI was similar to control as regards sensory and textural properties whereas 4% CPI was significantly different, limiting its inclusion level to 2%. There was a trend for higher sensory acceptability scores for GCPI containing bread compared DCPI. Whole egg was replaced by 20% by GCPI (3.5%) in sponge cake without affecting the sensory acceptability, whereas CPI and DCPI supplemented cakes were significantly different than the control. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Acoustic Emission Analysis of Damage Progression in Thermal Barrier Coatings Under Thermal Cyclic Conditions

    Science.gov (United States)

    Appleby, Matthew; Zhu, Dongming; Morscher, Gregory

    2015-01-01

    Damage evolution of electron beam-physical vapor deposited (EBVD-PVD) ZrO2-7 wt.% Y2O3 thermal barrier coatings (TBCs) under thermal cyclic conditions was monitored using an acoustic emission (AE) technique. The coatings were heated using a laser heat flux technique that yields a high reproducibility in thermal loading. Along with AE, real-time thermal conductivity measurements were also taken using infrared thermography. Tests were performed on samples with induced stress concentrations, as well as calcium-magnesium-alumino-silicate (CMAS) exposure, for comparison of damage mechanisms and AE response to the baseline (as-produced) coating. Analysis of acoustic waveforms was used to investigate damage development by comparing when events occurred, AE event frequency, energy content and location. The test results have shown that AE accumulation correlates well with thermal conductivity changes and that AE waveform analysis could be a valuable tool for monitoring coating degradation and provide insight on specific damage mechanisms.

  2. Assessment indices for uniform and non-uniform thermal environments

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Different assessment indices for thermal environments were compared and selected for proper assessment of indoor thermal environments.30 subjects reported their overall thermal sensation,thermal comfort,and thermal acceptability in uniform and non-uniform conditions.The results show that these three assessment indices provide equivalent evaluations in uniform environments.However,overall thermal sensation differs from the other two indices and cannot be used as a proper index for the evaluation of non-uniform environments.The relationship between the percentage and the mean vote for each index is established.

  3. Adaptive thermal comfort for buildings in Portugal based on occupants' thermal perception

    Energy Technology Data Exchange (ETDEWEB)

    Matias, L.; Pina Santos, C.; Rebelo, M. [LNEC National Laboratory for Civil Engineering, Lisbon (Portugal); Almeida, S. [FCT Foundation for Science and Technology, Lisbon (Portugal); Correia Guedes, M. [IST Higher Technical Inst., Lisbon (Portugal)

    2009-07-01

    The use of air conditioning systems in Portugal has increased in recent years. Most new service buildings are equipped with mechanical air conditioning systems, either due to commercial reasons, productivity, or due to high internal thermal loads, and solar gains through windows. However, a large percentage of older service buildings are still naturally ventilated. In ASHRAE 55 thermal comfort standard, an adaptive model was adopted as an optional method for determining acceptable thermal conditions in naturally conditioned spaces. Recently, Portugal's National Laboratory for Civil Engineering (LNEC) initiated an interdisciplinary research study in this field. The research team of physicists, social scientists, and civil engineers developed better modeling of adaptive thermal strategies. This paper described the adaptive approach that defined indoor thermal comfort requirements applicable to Portuguese buildings. The study focused on assessing, in real use conditions, indoor environments and the response of occupants of office and educational buildings, and homes for the elderly. The results were obtained from 285 field surveys carried out on 40 buildings and a set of 2367 questionnaires completed by occupants. Field surveys assessed and measured the main indoor environmental parameters during summer, winter and mid-season. This paper included the results of the analysis to the occupants' thermal perception and expectation, by relating them to both measured and collected indoor thermal environments and outdoor climate. The relation between the occupants' thermal sensation and preference was analysed for different types of activities, throughout different seasons. Results showed that occupants may tolerate broader temperature ranges than those indicated in current standards, particularly in the heating season. 10 refs., 3 tabs., 9 figs.

  4. Influence of thermal buoyancy on vertical tube bundle thermal density head predictions under transient conditions

    International Nuclear Information System (INIS)

    Lin, H.C.; Kasza, K.E.

    1984-01-01

    The thermal-hydraulic behavior of an LMFBR system under various types of plant transients is usually studied using one-dimensional (1-D) flow and energy transport models of the system components. Many of the transient events involve the change from a high to a low flow with an accompanying change in temperature of the fluid passing through the components which can be conductive to significant thermal bouyancy forces. Thermal bouyancy can exert its influence on system dynamic energy transport predictions through alterations of flow and thermal distributions which in turn can influence decay heat removal, system-response time constants, heat transport between primary and secondary systems, and thermal energy rejection at the reactor heat sink, i.e., the steam generator. In this paper the results from a comparison of a 1-D model prediction and experimental data for vertical tube bundle overall thermal density head and outlet temperature under transient conditions causing varying degrees of thermal bouyancy are presented. These comparisons are being used to generate insight into how, when, and to what degree thermal buoyancy can cause departures from 1-D model predictions

  5. An evaluation model for indoor environmental quality (IEQ) acceptance in residential buildings

    International Nuclear Information System (INIS)

    Lai, A.C.K.; Mui, K.W.; Wong, L.T.; Law, L.Y.

    2009-01-01

    The indoor environmental quality (IEQ) in residential buildings is examined from the prospect of an occupant's acceptance in four aspects: thermal comfort, indoor air quality, noise level and illumination level. Based on the evaluations by 125 occupants living in 32 typical residential apartments in Hong Kong, this study proposes empirical expressions to approximate the overall IEQ acceptance with respect to four contributors, namely operative temperature, carbon dioxide concentration, equivalent noise level and illumination level, via a multivariate logistic regression model. A range of IEQ acceptances for regular residential conditions is determined and the dependence of the predicted overall IEQ acceptance on the variations of the contributors is discussed. The proposed overall IEQ acceptance can be used as a quantitative assessment criterion for similar residential environments where an occupant's evaluation is expected. (author)

  6. 42 CFR 484.18 - Condition of participation: Acceptance of patients, plan of care, and medical supervision.

    Science.gov (United States)

    2010-10-01

    ..., and medical supervision. Patients are accepted for treatment on the basis of a reasonable expectation that the patient's medical, nursing, and social needs can be met adequately by the agency in the... 42 Public Health 5 2010-10-01 2010-10-01 false Condition of participation: Acceptance of patients...

  7. Conditioned pain modulation dampens the thermal grill illusion.

    Science.gov (United States)

    Harper, D E; Hollins, M

    2017-10-01

    The thermal grill illusion (TGI) refers to the perception of burning heat and often pain that arises from simultaneous cutaneous application of innocuous warm and cool stimuli. This study utilized conditioned pain modulation (CPM) to help elucidate the TGI's underlying neural mechanisms, including the debated role of ascending nociceptive signals in generating the illusion. To trigger CPM, subjects placed the left hand in noxious cold (6 °C) water before placing the right volar forearm onto a thermal grill. Lower pain and unpleasantness ratings of the grill in this CPM run compared to those in a control run (i.e. 33 °C water) were taken as evidence of CPM. To determine whether CPM reduces noxious heat pain and illusory heat pain equally, an experimental group of subjects rated pain and unpleasantness of a grill consisting of innocuous alternating warm (42 °C) and cool (18 °C) bars, while a control group rated a grill with all bars controlled to a noxious temperature (45 °C). CPM produced significant and comparable reductions in pain, unpleasantness and perceived heat of both noxious heat and the TGI. This result suggests that the TGI results from signals in nociceptive dorsal horn convergent neurons, since CPM involves descending inhibition with high selectivity for this neuronal population. More broadly, CPM's ability to produce a shift in perceived thermal sensation of both noxious heat and the TGI from 'hot' to 'warm' implies that nociceptive signals generated by a cutaneous stimulus can contribute to its perceived thermal intensity. Conditioned pain modulation reduces the perceived painfulness, unpleasantness and heat of the thermal grill illusion and noxious heat similarly. The results have important theoretical implications for both types of pain. © 2017 European Pain Federation - EFIC®.

  8. Ice thermal storage air conditioning system for electric load leveling; Denryoku heijunka to hyochikunetsu system

    Energy Technology Data Exchange (ETDEWEB)

    Shigenaga, Y. [Daikin Industries Ltd., Osaka (Japan)

    1998-08-15

    Thermal storage air conditioning system is the one to use energy stored into thermal storing materials by using night electric power and to operate effective air conditioning. Therefore, as load can be treated by the stored energy, volume of the apparatus can be reduced. And, by reduction of the consumed power at day time, it can contribute to leveling of electric power demand. In general, there are two types in the thermal storage method: one is a method to store as thermal energy, and the other is that to store as chemical energy. For conditions required for the storing materials, important elements on their actual uses are not only physical properties such as large thermal storage per unit and easy thermal in- and out-puts, but also safety, long-term reliability, and easy receiving and economics containing future. The ice thermal storage air conditioning system is classified at the viewpoint of type of ice, kind of thermal storing medium, melting method on using cooling and heating, kinds of thermal medium on cooling and heating. 3 refs., 5 figs., 2 tabs.

  9. Numerical study on lithium titanate battery thermal response under adiabatic condition

    International Nuclear Information System (INIS)

    Sun, Qiujuan; Wang, Qingsong; Zhao, Xuejuan; Sun, Jinhua; Lin, Zijing

    2015-01-01

    Highlights: • The thermal behavior of lithium titanate battery during cycling was investigated. • The temperature rate in charging was less than that of discharging in the cycling. • The temperature difference was less than 0.02 °C at 0.5 C in adiabatic condition. • The temperature distribution and thermal runaway of the battery were predicted. - Abstract: To analyze the thermal behavior of 945 mA h lithium titanate battery during charging and discharging processes, the experimental and numerical studies are performed in this work. The cathode and anode of the 945 mA h lithium titanate soft package battery are the lithium nickel–cobalt–manganese-oxide and lithium titanate, respectively. In the experiment, an Accelerating Rate Calorimeter combined with battery cycler is employed to investigate the electrochemical–thermal behavior during charge–discharge cycling under the adiabatic condition. In numerical simulation, one electrochemical-thermal model is adopted to predict the thermal response and validated with the experimental results. From both experimental and simulated results, the profile of potential and current, the heat generation, the temperature, the temperature changing rate and the temperature distribution in the cell are obtained and thermal runaway is predicted. The analysis of the electrochemical and thermal behavior is beneficial for the commercial application of lithium titanate battery in the fields of electric vehicles and hybrid electric vehicles

  10. Thermal comfort index and infrared temperatures for lambs subjected to different environmental conditions

    Directory of Open Access Journals (Sweden)

    Tiago do Prado Paim

    2014-10-01

    Full Text Available There is an abundance of thermal indices with different input parameters and applicabilities. Infrared thermography is a promising technique for evaluating the response of animals to the environment and differentiating between genetic groups. Thus, the aim of this study was to evaluate superficial body temperatures of lambs from three genetic groups under different environmental conditions, correlating these with thermal comfort indices. Forty lambs (18 males and 22 females from three genetic groups (Santa Inês, Ile de France × Santa Inês and Dorper × Santa Inês were exposed to three climatic conditions: open air, housed and artificial heating. Infrared thermal images were taken weekly at 6h, 12h and 21h at the neck, front flank, rear flank, rump, nose, skull, trunk and eye. Four thermal comfort indices were calculated using environmental measurements including black globe temperature, air humidity and wind speed. Artificial warming, provided by infrared lamps and wind protection, conserved and increased the superficial body temperature of the lambs, thus providing lower daily thermal ranges. Artificial warming did not influence daily weight gain or mortality. Skin temperatures increased along with increases in climatic indices. Again, infrared thermography is a promising technique for evaluating thermal stress conditions and differentiating environments. However, the use of thermal imaging for understanding animal responses to environmental conditions requires further study.

  11. Estimation of acceptable beam trip frequencies of accelerators for ADS and comparison with performances of existing accelerators

    International Nuclear Information System (INIS)

    Takei, Hayanori; Tsujimoto, Kazufumi; Nishihara, Kenji; Furukawa, Kazuro; Yano, Yoshiharu; Ogawa, Yujiro; Oigawa, Hiroyuki

    2009-09-01

    Frequent beam trips as experienced in existing high power proton accelerators may cause thermal fatigue problems in ADS components which may lead to degradation of their structural integrity and reduction of their lifetime. Thermal transient analyses were performed to investigate the effects of beam trips on the reactor components, with the objective of formulating ADS design that had higher engineering possibilities and determining the requirements for accelerator reliability. These analyses were made on the thermal responses of four parts of the reactor components; the beam window, the cladding tube, the inner barrel and the reactor vessel. Our results indicated that the acceptable frequency of beam trips ranged from 50 to 2x10 4 times per year depending on the beam trip duration. As the beam trips for durations exceeding five minutes were assumed to make the plant shut down and restart, the plant availability was estimated to be 70%. In order to consider measures to reduce the frequency of beam trips on the high power accelerator for ADS, we compared the acceptable frequency of beam trips with the operation data of existing accelerators. The result of this comparison showed that for typical conditions the beam trip frequency for durations of 10 seconds or less was within the acceptable level, while that exceeding five minutes should be reduced to about 1/30 to satisfy the thermal stress conditions. (author)

  12. Human-biometeorological conditions and thermal perception in a Mediterranean coastal park

    Science.gov (United States)

    Saaroni, Hadas; Pearlmutter, David; Hatuka, Tali

    2015-10-01

    This study looks at the interrelation of human-biometeorological conditions, physiological thermal stress and subjective thermal perception in the design and use of a new waterfront park in Tel-Aviv, Israel. Our initial assumption was that the park's design would embody a comprehensive response to the area's ever-increasing heat stress and water shortage. However, almost half of it is covered by grass lawns, irrigated with fresh water, while the remaining area is mainly covered with concrete paving, with minimal shading and sparse trees. We hypothesized that stressful thermal conditions would prevail in the park in the summer season and would be expressed in a high discomfort perception of its users. Thermo-physiological stress conditions in a typical summer month were compared with the subjective comfort perceptions of pedestrians surveyed in the park. It was found that even during mid-day hours, the level of thermal stress tends to be relatively mild, owing largely to the strong sea breeze and despite the high intensity of solar radiation. Moreover, it appears that the largely favorable perception of comfort among individuals may also result from socio-cultural aspects related to their satisfaction with the park's aesthetic attractiveness and in fact its very existence. Adaptive planning is proposed for such vulnerable regions, which are expected to experience further aggravation in thermal comfort due to global as well as localized warming trends.

  13. Enthalpy estimation for thermal comfort and energy saving in air conditioning system

    International Nuclear Information System (INIS)

    Chu, C.-M.; Jong, T.-L.

    2008-01-01

    The thermal comfort control of a room must consider not only the thermal comfort level but also energy saving. This paper proposes an enthalpy estimation that is conducive for thermal comfort control and energy saving. The least enthalpy estimator (LEE) combines the concept of human thermal comfort with the theory of enthalpy to predict the load for a suitable setting pair in order to maintain more precisely the thermal comfort level and save energy in the air conditioning system

  14. Investigation on the Temporal Surface Thermal Conditions for Thermal Comfort Researches Inside A Vehicle Cabin Under Summer Season Climate

    Directory of Open Access Journals (Sweden)

    Zhang Wencan

    2016-01-01

    Full Text Available With the proposes of improving occupant's thermal comfort and reducing the air conditioning power consumption, the present research carried out a comprehensive study on the surface thermal conductions and their influence parameters. A numerical model was built considering the transient conduction, convective and radiation heat transfer inside a vehicle cabin. For more accurate simulation of the radiation heat transfer behaviors, the radiation was considered into two spectral bands (short wave and long wave radiation, and the solar radiation was calculated by two solar fluxes (beam and diffuse solar radiation. An experiment was conducted to validate the numerical approach, showing a good agreement with the surface temperature. The surface thermal conditions were numerically simulated. The results show that the solar radiation is the most important factor in determining the internal surface thermal conditions. Effects of the window glass properties and the car body surface conditions were investigated. The numerical calculation results indicate that reducing the transitivity of window glass can effectively reduce the internal surface temperature. And the reflectivity of the vehicle cabin also has an important influence on the surface temperature, however, it's not so obvious as comparison to the window glass.

  15. Modeling and Simulation of Thermal Performance of Solar-Assisted Air Conditioning System under Iraq Climate

    Directory of Open Access Journals (Sweden)

    Najim Abid Jassim

    2016-08-01

    Full Text Available In Iraq most of the small buildings deployed a conventional air conditioning technology which typically uses electrically driven compressor systems which exhibits several clear disadvantages such as high energy consumption, high electricity at peak loads. In this work a thermal performance of air conditioning system combined with a solar collector is investigated theoretically. The hybrid air conditioner consists of a semi hermetic compressor, water cooled shell and tube condenser, thermal expansion valve and coil with tank evaporator. The theoretical analysis included a simulation for the solar assisted air-conditioning system using EES software to analyze the effect of different parameters on the power consumption of compressor and the performance of system. The results show that refrigeration capacity is increased from 2.7 kW to 4.4kW, as the evaporating temperature increased from 3 to 18 ºC. Also the power consumption is increased from 0.89 kW to 1.08 kW. So the COP of the system is increased from 3.068 to 4.117. The power consumption is increased from 0.897 kW to 1.031 kW as the condensing temperature increased from 35 ºC to 45 ºC. While the COP is decreased from 3.89 to 3.1. The power consumption is decreased from 1.05 kW to 0.7kW as the solar radiation intensity increased from 300 W/m2 to 1000 W/m2, while the COP is increased from 3.15 to 4.8. A comparison between the simulation and available experimental data showed acceptable agreement.

  16. Thermal tests of a transport / Storage cask in buried conditions

    International Nuclear Information System (INIS)

    Yamakawa, H.; Gomi, Y.; Saegusa, T.; Ito, C.

    1998-01-01

    Thermal tests for a hypothetical accident which simulated accidents caused by building collapse in case of an earthquake were conducted using a full-scale dry type transport and storage cask (total heat load: 23 kW). The objectives of these tests were to clarify the heat transfer features of the buried cask under such accidents and the time limit for maintaining the thermal integrity of the cask. Moreover, thermal analyses of the test cask under the buried conditions were carried out on basis of experimental results to establish methodology for the thermal analysis. The characteristics of the test cask are described as well as the test method used. The heat transfer features of the buried cask under such accidents and a time for maintaining the thermal integrity of the cask have been obtained. (O.M.)

  17. Influence of anomalous thermal losses of ignition conditions

    International Nuclear Information System (INIS)

    Coppi, B.; Tang, W.M.

    1986-05-01

    In the process of achieving ignition conditions, it is likely that microinstabilities, which lead to anomalous thermal transport of the fusing nuclei, will be present. When such phenomena are taken into account, an appropriate formulation of ignition criteria becomes necessary. In particular, a new type of plasma density limit is identified

  18. On the determination of the thermal comfort conditions of a metropolitan city underground railway.

    Science.gov (United States)

    Katavoutas, George; Assimakopoulos, Margarita N; Asimakopoulos, Dimosthenis N

    2016-10-01

    Although the indoor thermal comfort concept has received increasing research attention, the vast majority of published work has been focused on the building environment, such as offices, residential and non-residential buildings. The present study aims to investigate the thermal comfort conditions in the unique and complex underground railway environment. Field measurements of air temperature, air humidity, air velocity, globe temperature and the number of passengers were conducted in the modern underground railway of Athens, Greece. Environmental monitoring was performed in the interior of two types of trains (air-conditioned and forced air ventilation cabins) and on selected platforms during the summer period. The thermal comfort was estimated using the PMV (predicted mean vote) and the PPD (predicted percentage dissatisfied) scales. The results reveal that the recommended thermal comfort requirements, although at relatively low percentages are met only in air-conditioned cabins. It is found that only 33% of the PPD values in air-conditioned cabins can be classified in the less restrictive comfort class C, as proposed by ISO-7730. The thermal environment is "slightly warm" in air-conditioned cabins and "warm" in forced air ventilation cabins. In addition, differences of the thermal comfort conditions on the platforms are shown to be associated with the depth and the design characteristics of the stations. The average PMV at the station with small depth is 0.9 scale points higher than that of the station with great depth. The number of passengers who are waiting at the platforms during daytime reveals a U-shaped pattern for a deep level station and an inverted course of PMV for a small depth station. Further, preliminary observations are made on the distribution of air velocity on the platforms and on the impact of air velocity on the thermal comfort conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Thermal resistivity of tungsten grades under fusion relevant conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wirtz, M.; Linke, J.; Pintsuk, G. [Forschungszentrum Juelich (Germany). EURATOM Association

    2010-05-15

    Controlled nuclear fusion on earth is a very promising but also a very challenging task. Fusion devices like ITER and DEMO are major steps on the way of solving the energy problems of the future. However, the realisation of such thermonuclear fusion reactors still needs high efforts in many areas of research. One of the most critical issues is the field of in - vessel materials and components and in particular the plasma facing material (PFM). This not only has to be compatible to the heat sink material being able to withstand thermal fatigue loading conditions during steady state heat loading (up to 20 MW/m{sup 2}) but also has to withstand extreme thermal loads during transient events. The latter are divided into normal and off normal events, such as plasma disruptions or vertical displacement events (VDEs), resulting in irreversible damage of the material. Therefore they have to be avoided in future fusion devices by an improved plasma control. In contrast, edge localized modes (ELMs) occur during normal operation and are the result of complex plasma configuration. In the next step experiment ITER they are generated with a frequency of {>=} 1 Hz and a duration of 200 - 500 {mu}s depositing energies of {<=} 1 MJ/m{sup 2}. One of the most promising materials for the application as PFM in particular in the divertor region is tungsten. Its main advantages are a high thermal conductivity, a high melting temperature, a low tritium inventory and a low erosion rate. However there are some drawbacks like a high ductile to brittle transitions temperature (DBTT), its high atomic number Z and the remarkable neutron irradiation induced activation and degradation of its mechanical properties. The main aim of future R and D will be to understand the mechanisms of thermal induced damages and subsequently to minimize these types of damages. Therefore various tungsten grades have to be tested under fusion relevant conditions, e.g. by electron, ion or plasma beam exposure; the

  20. Simple method of calculating the transient thermal performance of composite material and its applicable condition

    Institute of Scientific and Technical Information of China (English)

    张寅平; 梁新刚; 江忆; 狄洪发; 宁志军

    2000-01-01

    Degree of mixing of composite material is defined and the condition of using the effective thermal diffusivity for calculating the transient thermal performance of composite material is studied. The analytical result shows that for a prescribed precision of temperature, there is a condition under which the transient temperature distribution in composite material can be calculated by using the effective thermal diffusivity. As illustration, for the composite material whose temperatures of both ends are constant, the condition is presented and the factors affecting the relative error of calculated temperature of composite materials by using effective thermal diffusivity are discussed.

  1. Human thermal comfort conditions and urban planning in hot-humid climates-The case of Cuba.

    Science.gov (United States)

    Rodríguez Algeciras, José Abel; Coch, Helena; De la Paz Pérez, Guillermo; Chaos Yeras, Mabel; Matzarakis, Andreas

    2016-08-01

    Climate regional characteristics, urban environmental conditions, and outdoors thermal comfort requirements of residents are important for urban planning. Basic studies of urban microclimate can provide information and useful resources to predict and improve thermal conditions in hot-humid climatic regions. The paper analyzes the thermal bioclimate and its influence as urban design factor in Cuba, using Physiologically Equivalent Temperature (PET). Simulations of wind speed variations and shade conditions were performed to quantify changes in thermal bioclimate due to possible modifications in urban morphology. Climate data from Havana, Camagüey, and Santiago of Cuba for the period 2001 to 2012 were used to calculate PET with the RayMan model. The results show that changes in meteorological parameters influence the urban microclimate, and consequently modify the thermal conditions in outdoors spaces. Shade is the predominant strategy to improve urban microclimate with more significant benefits in terms of PET higher than 30 °C. For climatic regions such as the analyzed ones, human thermal comfort can be improved by a wind speed modification for thresholds of PET above 30 °C, and by a wind speed decreases in conditions below 26 °C. The improvement of human thermal conditions is crucial for urban sustainability. On this regards, our study is a contribution for urban designers, due to the possibility of taking advantage of results for improving microclimatic conditions based on urban forms. The results may enable urban planners to create spaces that people prefer to visit, and also are usable in the reconfiguration of cities.

  2. Occupants' adaptive responses and perception of thermal environment in naturally conditioned university classrooms

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Runming [The School of Construction Management and Engineering, The University of Reading, Whiteknights, PO Box 219, Reading RG6 6AW (United Kingdom); The Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400042 (China); Liu, Jing [The School of Construction Management and Engineering, The University of Reading, Whiteknights, PO Box 219, Reading RG6 6AW (United Kingdom); Li, Baizhan [The Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400042 (China); Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environment (Ministry of Education), Chongqing University, Chongqing 400042 (China)

    2010-03-15

    A year-long field study of the thermal environment in university classrooms was conducted from March 2005 to May 2006 in Chongqing, China. This paper presents the occupants' thermal sensation votes and discusses the occupants' adaptive response and perception of the thermal environment in a naturally conditioned space. Comparisons between the Actual Mean Vote (AMV) and Predicted Mean Vote (PMV) have been made as well as between the Actual Percentage of Dissatisfied (APD) and Predicted Percentage of Dissatisfied (PPD). The adaptive thermal comfort zone for the naturally conditioned space for Chongqing, which has hot summer and cold winter climatic characteristics, has been proposed based on the field study results. The Chongqing adaptive comfort range is broader than that of the ASHRAE Standard 55-2004 in general, but in the extreme cold and hot months, it is narrower. The thermal conditions in classrooms in Chongqing in summer and winter are severe. Behavioural adaptation such as changing clothing, adjusting indoor air velocity, taking hot/cold drinks, etc., as well as psychological adaptation, has played a role in adapting to the thermal environment. (author)

  3. Heat exchange studies on coconut oil cells as thermal energy storage for room thermal conditioning

    Science.gov (United States)

    Sutjahja, I. M.; Putri, Widya A.; Fahmi, Z.; Wonorahardjo, S.; Kurnia, D.

    2017-07-01

    As reported by many thermal environment experts, room air conditioning might be controlled by thermal mass system. In this paper we discuss the performance of coconut oil cells as room thermal energy storage. The heat exchange mechanism of coconut oil (CO) which is one of potential organic Phase Change Material (PCM) is studied based on the results of temperature measurements in the perimeter and core parts of cells. We found that the heat exchange performance, i.e. heat absorption and heat release processes of CO cells are dominated by heat conduction in the sensible solid from the higher temperature perimeter part to the lower temperature core part and heat convection during the solid-liquid phase transition and sensible liquid phase. The capability of heat absorption as measured by the reduction of air temperature is not influenced by CO cell size. Besides that, the application of CO as the thermal mass has to be accompanied by air circulation to get the cool sensation of the room’s occupants.

  4. Experimental study of the influence of anticipated control on human thermal sensation and thermal comfort.

    Science.gov (United States)

    Zhou, X; Ouyang, Q; Zhu, Y; Feng, C; Zhang, X

    2014-04-01

    To investigate whether occupants' anticipated control of their thermal environment can influence their thermal comfort and to explain why the acceptable temperature range in naturally ventilated environments is greater than that in air-conditioned environments, a series of experiments were conducted in a climate chamber in which the thermal environment remained the same but the psychological environment varied. The results of the experiments show that the ability to control the environment can improve occupants' thermal sensation and thermal comfort. Specifically, occupants' anticipated control decreased their thermal sensation vote (TSV) by 0.4-0.5 and improved their thermal comfort vote (TCV) by 0.3-0.4 in neutral-warm environment. This improvement was due exclusively to psychological factors. In addition, having to pay the cost of cooling had no significant influence on the occupants' thermal sensation and thermal comfort in this experiment. Thus, having the ability to control the thermal environment can improve occupants' comfort even if there is a monetary cost involved. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Thermal history and comfort in a Brazilian subtropical climate: a 'cool' addiction hypothesis

    OpenAIRE

    Vecchi, Renata De; Cândido, Christhina Maria; Lamberts, Roberto

    2016-01-01

    Abstract Currently, there is a rising trend for commercial buildings to use air conditioning to provide indoor thermal comfort. This paper focuses on the impact of prolonged exposure to indoor air-conditioned environments on occupants' thermal acceptability and preferences in a mixed-mode building in Brazil. Questionnaires were administered while indoor microclimatic measurements were carried out (i.e., air temperature, radiant air temperature, air speed and humidity). Results suggest signifi...

  6. Thermal Dehydration Kinetics of Gypsum and Borogypsum under Non-isothermal Conditions

    Institute of Scientific and Technical Information of China (English)

    I.Y.Elbeyli; S.Piskin

    2004-01-01

    Thermal dehydration of gypsum and borogypsum was investigated under nonisothermal conditions in air by using simultaneous thermogravimetric-differential thermal analyzer. Nonisothermal experiments were carried out at various linear heating rates. Kinetics of dehydration in the temperature range of 373-503 K were evaluated from the DTA (differential thermal analysis)-TGA (thermogravimetric analysis) data by means of Coats-Redfern,Kissinger and Doyle Equations. Values of the activation energy and the pre-exponential factor of the dehydration were calculated. The results of thermal experiments and kinetic parameters indicated that borogypsum is similar to gypsum from dehydration mechanism point of view although it consists of boron and small amount of alkali metal oxides.

  7. Theoretical and experimental investigations of thermal conditions of household biogas plant

    Directory of Open Access Journals (Sweden)

    Zhelykh Vasil

    2016-06-01

    Full Text Available The construction of domestic continuous bioreactor is proposed. The modeling of thermal modes of household biogas plant using graph theory was done. The correction factor taking into account with the influence of variables on its value was determined. The system of balance equations for the desired thermal conditions in the bioreactor was presented.

  8. Thermal properties of bentonite under extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Vasicek, R. [Czech Technical Univ., Centre of Experimental Geotechnics, Faculty of Civil Engineering, Prague (Czech Republic)

    2005-07-01

    Centre of Experimental Geotechnics (CEG) deals with the research of the behaviour of bentonite and clays. The measurement of thermal properties is not so frequent test in geotechnical laboratory but in relation to deep repository it is a part which should not be overlooked. The reason is the heat generated by canister with spent nuclear fuel and possible influence of the heat on the materials of the engineered barrier. In the initial stages following the burial of canister with the waste the barrier materials will be exposed to elevated temperature. According to existing information, these temperatures should not exceed 90 C. That heat can induce a creation of cracks and opening of joint between highly compacted blocks. It will predispose the bentonite barrier to penetration of water from surrounding towards to canister. Therefore easy removal of heat through the barrier is required. It is essential that the tests aimed at determining the real values of measured parameters are carried out in conditions identical with those anticipated in a future disposal system. These relatively complicated thermophysical tests are logical continuation of the simple ones, carried out under laboratory temperature and on not fully saturated samples without possibility to measure the swelling pressure. Thermophysical properties and swelling pressure are dominantly influenced by water content (which is influenced by temperature). Therefore is important to realize the tests under different moisture and thermal conditions. These tests are running at the APT-PO1 Analyser, designed to fulfill mentioned requirements - it allows measurement of thermal properties under temperature up to 200 C and swelling pressure up to 20 MPa. The device is capable to register the evolution of temperature, swelling and vapor pressure. The measurement of thermal conductivity and volume heat capacity is realized by the dynamic impulse method with point source of heat. Four types of tests are possible: at

  9. Guidelines on Thermal Comfort of Air Conditioned Indoor Environment

    Science.gov (United States)

    Miura, Toyohiko

    The thermal comfort of air conditioned indoor environment for workers depended, of course, on metabolic rate of work, race, sex, age, clothing, climate of the district and state of acclimatization. The attention of the author was directed to the seasonal variation and the sexual difference of comfortable temperature and a survey through a year was conducted on the thermal comfort, and health conditions of workers engaged in light work in a precision machine factory, in some office workers. Besides, a series of experiments were conducted for purpose of determinning the optimum temperature of cooling in summer time in relation to the outdoor temperature. It seemed that many of workers at present would prefer somewhat higher temperature than those before the World War II. Forty years ago the average homes and offices were not so well heated as today, and clothing worn on the average was considerably heavier.

  10. Thermal Conductivity of the Multicomponent Neutral Atmosphere

    Science.gov (United States)

    Pavlov, A. V.

    2017-12-01

    Approximate expressions for the thermal conductivity coefficient of the multicomponent neutral atmosphere consisting of N2, O2, O, He, and H are analyzed and evaluated for the atmospheric conditions by comparing them with that given by the rigorous hydrodynamic theory. The new approximations of the thermal conductivity coefficients of simple gases N2, O2, O, He, and H are derived and used. It is proved that the modified Mason and Saxena approximation of the atmospheric thermal conductivity coefficient is more accurate in reproducing the atmospheric values of the rigorous hydrodynamic thermal conductivity coefficient in comparison with those that are generally accepted in atmospheric studies. This approximation of the thermal conductivity coefficient is recommended to use in calculations of the neutral temperature of the atmosphere.

  11. Thermal shock behaviour of different tungsten grades under varying conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wirtz, Oliver Marius

    2012-07-19

    Thermonuclear fusion power plants are a promising option to ensure the energy supply for future generations, but in many fields of research enormous challenges have to be faced. A major step on the way to the prototype fusion reactor DEMO will be ITER which is build in Cadarache, southern France. One of the most critical issues is the field of in-vessel materials and components, in particular the plasma facing materials (PFM). PFMs that will be used in a device like ITER have to withstand severe environmental conditions in terms of steady state and transient thermal loads as well as high particle fluxes such as hydrogen, helium and neutrons. Candidate wall materials are beryllium, tungsten and carbon based materials like CFC (carbon fibre composite). Tungsten is the most promising material for an application in the divertor region with very severe loading conditions and it will most probably also be used as PFM for DEMO. Hence, this work focuses on the investigation of the thermal shock response of different tungsten grades in order to understand the damage mechanisms and to identify material parameters which influence this behaviour under ITER and DEMO relevant operation conditions. Therefore the microstructure and the mechanical and thermal properties of five industrially manufactured tungsten grades were characterised. All five tungsten grades were exposed to transient thermal events with very high power densities of up to 1.27 GWm{sup -2} at varying base temperatures between RT and 600 C in the electron beam device JUDITH 1. The pulse numbers were limited to a maximum of 1000 in order to avoid immoderate workload on the test facility and to have enough time to cover a wide range of loading conditions. The results of this damage mapping enable to define different damage and cracking thresholds for the investigated tungsten grades and to identify certain material parameters which influence the location of these thresholds and the distinction of the induced

  12. Thermal shock behaviour of different tungsten grades under varying conditions

    International Nuclear Information System (INIS)

    Wirtz, Oliver Marius

    2012-01-01

    Thermonuclear fusion power plants are a promising option to ensure the energy supply for future generations, but in many fields of research enormous challenges have to be faced. A major step on the way to the prototype fusion reactor DEMO will be ITER which is build in Cadarache, southern France. One of the most critical issues is the field of in-vessel materials and components, in particular the plasma facing materials (PFM). PFMs that will be used in a device like ITER have to withstand severe environmental conditions in terms of steady state and transient thermal loads as well as high particle fluxes such as hydrogen, helium and neutrons. Candidate wall materials are beryllium, tungsten and carbon based materials like CFC (carbon fibre composite). Tungsten is the most promising material for an application in the divertor region with very severe loading conditions and it will most probably also be used as PFM for DEMO. Hence, this work focuses on the investigation of the thermal shock response of different tungsten grades in order to understand the damage mechanisms and to identify material parameters which influence this behaviour under ITER and DEMO relevant operation conditions. Therefore the microstructure and the mechanical and thermal properties of five industrially manufactured tungsten grades were characterised. All five tungsten grades were exposed to transient thermal events with very high power densities of up to 1.27 GWm -2 at varying base temperatures between RT and 600 C in the electron beam device JUDITH 1. The pulse numbers were limited to a maximum of 1000 in order to avoid immoderate workload on the test facility and to have enough time to cover a wide range of loading conditions. The results of this damage mapping enable to define different damage and cracking thresholds for the investigated tungsten grades and to identify certain material parameters which influence the location of these thresholds and the distinction of the induced damages

  13. Effects of growth conditions on thermal profiles during Czochralski silicon crystal growth

    Science.gov (United States)

    Choe, Kwang Su; Stefani, Jerry A.; Dettling, Theodore B.; Tien, John K.; Wallace, John P.

    1991-01-01

    An eddy current testing method was used to continuously monitor crystal growth process and investigate the effects of growth conditions on thermal profiles during Czochralski silicon crystal growth. The experimental concept was to monitor the intrinsic electrical conductivities of the growing crystal and deduce temperature values from them. In terms of the experiments, the effects of changes in growth parameters, which include the crystal and crucible rotation rates, crucible position, and pull rate, and hot-zone geometries were investigated. The results show that the crystal thermal profile could shift significantly as a function of crystal length if the closed-loop control fails to maintain a constant thermal condition. As a direct evidence to the effects of the melt flow on heat transfer processes, a thermal gradient minimum was observed when the crystal/crucible rotation combination was 20/-10 rpm cw. The thermal gradients in the crystal near the growth interface were reduced most by decreasing the pull rate or by reducing the radiant heat loss to the environment; a nearly constant axial thermal gradient was achieved when either the pull rate was decreased by half, the height of the exposed crucible wall was doubled, or a radiation shield was placed around the crystal. Under these conditions, the average axial thermal gradient along the surface of the crystal was about 4-5°C/mm. When compared to theoretical results found in literature, the axial profiles correlated well with the results of the models which included radiant interactions. However, the radial gradients estimated from three-frequency data were much higher than what were predicted by known theoretical models. This discrepancy seems to indicate that optical phenomenon within the crystal is significant and should be included in theoretical modeling.

  14. Thermal comfort of heterogeneous and dynamic indoor conditions - An overview

    NARCIS (Netherlands)

    Mishra, A.K.; Loomans, M.G.L.C.; Hensen, J.L.M.

    2016-01-01

    The buildings sector, being a leading energy consumer, would need to lead in conservation efforts as well. There is a growing consensus that variability in indoor conditions can be acceptable to occupants, improve comfort perception, and lower building energy consumption. This work endeavours to

  15. Thermal hydraulic feasibility assessment of the spent nuclear fuel project

    International Nuclear Information System (INIS)

    Heard, F.J.

    1996-01-01

    A series of analyses have been completed investigating the thermal-hydraulic performance and feasibility of the Spent Nuclear Fuel Project (SNFP) Integrated Process Strategy (IPS). The goal was to develop a series of thermal-hydraulic models that could respond to all process and safety related issues that may arise pertaining to the SNFP, as well as provide a basis for validation of the results. Results show that there is a reasonable envelope for process conditions and requirements that are thermally and hydraulically acceptable

  16. INDOOR THERMAL CONDITION OF FACTORY BUILDING IN BANGLADESH

    Directory of Open Access Journals (Sweden)

    Muhammed Abdullah Al Sayem Khan

    2011-12-01

    Full Text Available Bangladesh is a developing country and has a lot of factories for different products for local use and also export to abroad. Garments industries are one of the top most items of exported items. A huge number of populations are working in garments industries. But these factories are not well designed in sense of the thermal environment. Workers experiences sickness related to indoor environment. The productions of these factories are affected due to employees’ health condition. The research is done in two different methods. One is empirical data collection using thermal data loggers and the other is questionnaire survey on the spots for three factory buildings. The field study was conducted in four different months of the same year during winter and summer period. Expected findings of this research are that the indoor environment is not comfortable for works at day time during summer season. This research will help the factory workers in providing a comfortable thermal environment and also help the employers or factory owners to increase their production margin.

  17. Sidewalk Landscape Structure and Thermal Conditions for Child and Adult Pedestrians

    Science.gov (United States)

    Kim, Young-Jae; Lee, Chanam; Kim, Jun-Hyun

    2018-01-01

    Walking is being promoted for health and transportation purposes across all climatic regions in the US and beyond. Despite this, an uncomfortable microclimate condition along sidewalks is one of the major deterrents of walking, and more empirical research is needed to determine the risks of heat exposure to pedestrians while walking. This study examined the effect of street trees and grass along sidewalks on air temperatures. A series of thermal images were taken at the average heights of adults and children in the US to objectively measure the air temperatures of 10 sidewalk segments in College Station, TX, USA. After controlling the other key physical environmental conditions, sidewalks with more trees or wider grass buffer areas had lower air temperatures than those with less vegetation. Children were exposed to higher temperatures due to the greater exposure or proximity to the pavement surface, which tends to have higher radiant heat. Multivariate regression analysis suggested that the configuration of trees and grass buffers along the sidewalks helped to promote pleasant thermal conditions and reduced the differences in ambient air temperatures measured at child and adult heights. This study suggests that street trees and vegetated ground help reduce the air temperatures, leading to more thermally comfortable environments for both child and adult pedestrians in warm climates. The thermal implications of street landscape require further attention by researchers and policy makers that are interested in promoting outdoor walking. PMID:29346312

  18. The importance of thermal loading conditions to waste package performance at Yucca Mountain

    International Nuclear Information System (INIS)

    Buscheck, T.A.; Nitao, J.J.

    1994-10-01

    Temperature and relative humidity are primary environmental factors affecting waste package corrosion rates for the potential repository in the unsaturated zone at Yucca Mountain, Nevada. Under ambient conditions, the repository environment is quite humid. If relative humidity is low enough (<70%), corrosion will be minimal. Under humid conditions, corrosion is reduced if the temperature is low (<60 C). Using the V-TOUGH code, the authors model thermo-hydrological flow to investigate the effect of repository heat on temperature and relative humidity in the repository for a wide range of thermal loads. These calculations indicate that repository heat may substantially reduce relative humidity on the waste package, over hundreds of years for low thermal loads and over tens of thousands of year for high thermal loads. Temperatures associated with a given relative humidity decrease with increasing thermal load. Thermal load distributions can be optimized to yield a more uniform reduction in relative humidity during the boiling period

  19. Characterization of a thermoelectric cooler based thermal management system under different operating conditions

    International Nuclear Information System (INIS)

    Russel, M.K.; Ewing, D.; Ching, C.Y.

    2013-01-01

    The performance of a thermoelectric cooler (TEC) based thermal management system for an electronic packaging design that operates under a range of ambient conditions and system loads is examined using a standard model for the TEC and a thermal resistance network for the other components. Experiments were performed and it was found that the model predictions were in good agreement with the experimental results. An operating envelope is developed to characterize the TEC based thermal management system for peak and off peak operating conditions. Parametric studies were performed to analyze the effect of the number of TEC module(s) in the system, geometric factor of the thermo-elements and the cold to hot side thermal resistances on the system performance. The results showed that there is a tradeoff between the extent of off peak heat fluxes and ambient temperatures when the system can be operated at a low power penalty region and the maximum capacity of the system. - Highlights: ► A model was developed for thermal management systems using thermoelectric coolers. ► Model predictions were in good agreement with experimental results. ► An operating envelope was developed for peak and off peak conditions. ► The effect of the number of thermoelectric coolers on the system was determined.

  20. Mathematical model for thermal solar collectors by using magnetohydrodynamic Maxwell nanofluid with slip conditions, thermal radiation and variable thermal conductivity

    Directory of Open Access Journals (Sweden)

    Asif Mahmood

    Full Text Available Solar energy is the cleanest, renewable and most abundant source of energy available on earth. The main use of solar energy is to heat and cool buildings, heat water and to generate electricity. There are two types of solar energy collection system, the photovoltaic systems and the solar thermal collectors. The efficiency of any solar thermal system depend on the thermophysical properties of the operating fluids and the geometry/length of the system in which fluid is flowing. In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The flow is induced by a non-uniform stretching of the porous sheet and the uniform magnetic field is applied in the transverse direction to the flow. The non-Newtonian Maxwell fluid model is utilized for the working fluid along with slip boundary conditions. Moreover the high temperature effect of thermal radiation and temperature dependent thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for cu-water and TiO2-water nanofluids. Results are presented for the velocity and temperature profiles as well as the skin friction coefficient and Nusselt number and the discussion is concluded on the effect of various governing parameters on the motion, temperature variation, velocity gradient and the rate of heat transfer at the boundary. Keywords: Solar energy, Thermal collectors, Maxwell-nanofluid, Thermal radiation, Partial slip, Variable thermal conductivity

  1. Three dimensional neutronic/thermal-hydraulic coupled simulation of MSR in transient state condition

    International Nuclear Information System (INIS)

    Zhou, Jianjun; Zhang, Daling; Qiu, Suizheng; Su, Guanghui; Tian, Wenxi; Wu, Yingwei

    2015-01-01

    Highlights: • Developed a three dimensional neutronic/thermal-hydraulic coupled transient analysis code for MSR. • Investigated the neutron distribution and thermal-hydraulic characters of the core under transient condition. • Analyzed three different transient conditions of inlet temperature drop, reactivity jump and pump coastdown. - Abstract: MSR (molten salt reactor) use liquid molten salt as coolant and fuel solvent, which was the only one liquid reactor of six Generation IV reactor types. As a liquid reactor the physical property of reactor was significantly influenced by fuel salt flow and the conventional analysis methods applied in solid fuel reactors are not applicable for this type of reactors. The present work developed a three dimensional neutronic/thermal-hydraulic coupled code investigated the neutronics and thermo-hydraulics characteristics of the core in transient condition based on neutron diffusion theory and numerical heat transfer. The code consists of two group neutron diffusion equations for fast and thermal neutron fluxes and six group balance equations for delayed neutron precursors. The code was separately validated by neutron benchmark and flow and heat transfer benchmark. Three different transient conditions was analyzed with inlet temperature drop, reactivity jump and pump coastdown. The results provide some valuable information in design and research this kind of reactor

  2. Three dimensional neutronic/thermal-hydraulic coupled simulation of MSR in transient state condition

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jianjun [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xianning Road, 28, Xi’an 710049, Shaanxi (China); College of Mechanical and Power Engineering, China Three Gorges University, No 8, Daxue road, Yichang, Hubei 443002 (China); Zhang, Daling, E-mail: dlzhang@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xianning Road, 28, Xi’an 710049, Shaanxi (China); Qiu, Suizheng; Su, Guanghui; Tian, Wenxi; Wu, Yingwei [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xianning Road, 28, Xi’an 710049, Shaanxi (China)

    2015-02-15

    Highlights: • Developed a three dimensional neutronic/thermal-hydraulic coupled transient analysis code for MSR. • Investigated the neutron distribution and thermal-hydraulic characters of the core under transient condition. • Analyzed three different transient conditions of inlet temperature drop, reactivity jump and pump coastdown. - Abstract: MSR (molten salt reactor) use liquid molten salt as coolant and fuel solvent, which was the only one liquid reactor of six Generation IV reactor types. As a liquid reactor the physical property of reactor was significantly influenced by fuel salt flow and the conventional analysis methods applied in solid fuel reactors are not applicable for this type of reactors. The present work developed a three dimensional neutronic/thermal-hydraulic coupled code investigated the neutronics and thermo-hydraulics characteristics of the core in transient condition based on neutron diffusion theory and numerical heat transfer. The code consists of two group neutron diffusion equations for fast and thermal neutron fluxes and six group balance equations for delayed neutron precursors. The code was separately validated by neutron benchmark and flow and heat transfer benchmark. Three different transient conditions was analyzed with inlet temperature drop, reactivity jump and pump coastdown. The results provide some valuable information in design and research this kind of reactor.

  3. Implementation and verification of a coupled fire model as a thermal boundary condition within P3/THERMAL

    International Nuclear Information System (INIS)

    Hensinger, D.M.; Gritzo, L.A.; Koski, J.A.

    1996-01-01

    A user-defined boundary condition subroutine has been implemented within P3/THERMAL to represent the heat flux between a noncombusting object and an engulfing fire. The heat flux calculations includes a simple 2D fire model in which energy and radiative heat transport equations are solved to produce estimates of the heat fluxes at the fire-object interface. These estimates reflect radiative coupling between a cold object and the flow of hot combustion gases which has been observed in fire experiments. The model uses a database of experimental pool fire measurements for far field boundary conditions and volumetric heat release rates. Taking into account the coupling between a structure and the fire is an improvement over the σT 4 approximation frequently used as a boundary condition for engineered system response and is the preliminary step in the development of a fire model with a predictive capability. This paper describes the implementation of the fire model as a P3/THERMAL boundary condition and presents the results of a verification calculation carried out using the model

  4. Thermal comfort in air-conditioned mosques in the dry desert climate

    Energy Technology Data Exchange (ETDEWEB)

    Al-ajmi, Farraj F. [Department of Civil Engineering, College of Technological Studies, Shuwaikh 70654 (Kuwait)

    2010-11-15

    In Kuwait, as in most countries with a typical dry desert climate, the summer season is long with a mean daily maximum temperature of 45 C. Centralized air-conditioning, which is generally deployed from the beginning of April to the end of October, can have tremendous impact on the amount of electrical energy utilized to mechanically control the internal environment in mosque buildings. The indoor air temperature settings for all types of air-conditioned buildings and mosque buildings in particular, are often calculated based on the analytical model of ASHRAE 55-2004 and ISO 7730. However, a field study was conducted in six air-conditioned mosque buildings during the summers of 2007 to investigate indoor climate and prayers thermal comfort in state of Kuwait. The paper presents statistical data about the indoor environmental conditions in Kuwait mosque buildings, together with an analysis of prayer thermal comfort sensations for a total of 140 subjects providing 140 sets of physical measurements and subjective questionnaires were used to collect data. Results show that the neutral temperature (T{sub n}) of the prayers is found to be 26.1 C, while that for PMV is 23.3 C. Discrepancy of these values is in fact about 2.8 C higher than those predicted by PMV model. Therefore, thermal comfort temperature in Kuwait cannot directly correlate with ISO 7730 and ASHRAE 55-2004 standards. Findings from this study should be considered when designing air conditioning for mosque buildings. This knowledge can contribute towards the development of future energy-related design codes for Kuwait. (author)

  5. Attitudes of belgian students of medicine, philosophy, and law toward euthanasia and the conditions for its acceptance.

    Science.gov (United States)

    Roelands, Marc; Van den Block, Lieve; Geurts, Sylvie; Deliens, Luc; Cohen, Joachim

    2015-01-01

    Euthanasia is legal in Belgium if due care criteria are met, which is judged by committees including physicians, ethicists, and jurists. We examined whether students in these disciplines differ in how they judge euthanasia as an acceptable act. A cross-sectional, anonymous e-mail survey revealed that they have similar attitudes and accept its legalization. Therefore, joint decision-making of physicians, ethicists, and lawyers regarding euthanasia seems to have a common attitudinal base in Belgium. However, they differ to some extent regarding the conditions they put forward for euthanasia being acceptable. Philosophy of life (religion) was an independent predictor of these attitudes.

  6. Experimental study on occupant's thermal responses under the non-uniform conditions in vehicle cabin during the heating period

    Science.gov (United States)

    Zhang, Wencan; Chen, Jiqing; Lan, Fengchong

    2014-03-01

    The existing investigations on thermal comfort mostly focus on the thermal environment conditions, especially of the air-flow field and the temperature distributions in vehicle cabin. Less attention appears to direct to the thermal comfort or thermal sensation of occupants, even to the relationship between thermal conditions and thermal sensation. In this paper, a series of experiments were designed and conducted for understanding the non-uniform conditions and the occupant's thermal responses in vehicle cabin during the heating period. To accurately assess the transient temperature distribution in cabin in common daily condition, the air temperature at a number of positions is measured in a full size vehicle cabin under natural winter environment in South China by using a discrete thermocouples network. The occupant body is divided into nine segments, the skin temperature at each segment and the occupant's local thermal sensation at the head, body, upper limb and lower limb are monitored continuously. The skin temperature is observed by using a discrete thermocouples network, and the local thermal sensation is evaluated by using a seven-point thermal comfort survey questionnaire proposed by American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc(ASHRAE) Standard. The relationship between the skin temperature and the thermal sensation is discussed and regressed by statistics method. The results show that the interior air temperature is highly non-uniform over the vehicle cabin. The locations where the occupants sit have a significant effect on the occupant's thermal responses, including the skin temperature and the thermal sensation. The skin temperature and thermal sensation are quite different between body segments due to the effect of non-uniform conditions, clothing resistance, and the human thermal regulating system. A quantitative relationship between the thermal sensation and the skin temperature at each body segment of occupant in

  7. Thermal advantage of tracking solar collectors under Danish weather conditions

    DEFF Research Database (Denmark)

    Andersen, Elsa; Dragsted, Janne; Furbo, Simon

    2010-01-01

    Theoretical investigations have been carried out with the aim to elucidate the thermal advantage of tracking solar collectors for different weather conditions in Kgs. Lyngby, Denmark (55.8°N), and for the weather conditions in Sisimiut, Greenland (66.9°N), just north of the arctic circle....... The investigations are based on calculations with a newly developed program. Measured weather data from a solar radiation measurement station at Technical University of Denmark in Kgs. Lyngby Denmark in the period 1990 to 2002 and the Danish Design Reference Year, DRY data file are used in the investigations....... The weather data used for Sisimiut are based on a Test Reference Year, TRY weather data file. The thermal advantages of different tracking strategies is investigated for two flat plate solar collectors with different efficiencies, operated at different temperature levels. The investigations show...

  8. Sintering Characteristics of Multilayered Thermal Barrier Coatings Under Thermal Gradient and Isothermal High Temperature Annealing Conditions

    Science.gov (United States)

    Rai, Amarendra K.; Schmitt, Michael P.; Bhattacharya, Rabi; Zhu, Dongming; Wolfe, Douglas E.

    2014-01-01

    Pyrochlore oxides have most of the relevant attributes for use as next generation thermal barrier coatings such as phase stability, low sintering kinetics and low thermal conductivity. One of the issues with the pyrochlore oxides is their lower toughness and therefore higher erosion rate compared to the current state-of-the-art TBC material, yttria (6 to 8 wt%) stabilized zirconia (YSZ). In this work, sintering characteristics were investigated for novel multilayered coating consisted of alternating layers of pyrochlore oxide viz Gd2Zr2O7 and t' low k (rare earth oxide doped YSZ). Thermal gradient and isothermal high temperature (1316 C) annealing conditions were used to investigate sintering and cracking in these coatings. The results are then compared with that of relevant monolayered coatings and a baseline YSZ coating.

  9. Comparative evaluation of thermal decomposition behavior and thermal stability of powdered ammonium nitrate under different atmosphere conditions.

    Science.gov (United States)

    Yang, Man; Chen, Xianfeng; Wang, Yujie; Yuan, Bihe; Niu, Yi; Zhang, Ying; Liao, Ruoyu; Zhang, Zumin

    2017-09-05

    In order to analyze the thermal decomposition characteristics of ammonium nitrate (AN), its thermal behavior and stability under different conditions are studied, including different atmospheres, heating rates and gas flow rates. The evolved decomposition gases of AN in air and nitrogen are analyzed with a quadrupole mass spectrometer. Thermal stability of AN at different heating rates and gas flow rates are studied by differential scanning calorimetry, thermogravimetric analysis, paired comparison method and safety parameter evaluation. Experimental results show that the major evolved decomposition gases in air are H 2 O, NH 3 , N 2 O, NO, NO 2 and HNO 3 , while in nitrogen, H 2 O, NH 3 , NO and HNO 3 are major components. Compared with nitrogen atmosphere, lower initial and end temperatures, higher heat flux and broader reaction temperature range are obtained in air. Meanwhile, higher air gas flow rate tends to achieve lower reaction temperature and to reduce thermal stability of AN. Self-accelerating decomposition temperature of AN in air is much lower than that in nitrogen. It is considered that thermostability of AN is influenced by atmosphere, heating rate and gas flow rate, thus changes of boundary conditions will influence its thermostability, which is helpful to its safe production, storage, transportation and utilization. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Thermal Simulations, Open Boundary Conditions and Switches

    Science.gov (United States)

    Burnier, Yannis; Florio, Adrien; Kaczmarek, Olaf; Mazur, Lukas

    2018-03-01

    SU(N) gauge theories on compact spaces have a non-trivial vacuum structure characterized by a countable set of topological sectors and their topological charge. In lattice simulations, every topological sector needs to be explored a number of times which reflects its weight in the path integral. Current lattice simulations are impeded by the so-called freezing of the topological charge problem. As the continuum is approached, energy barriers between topological sectors become well defined and the simulations get trapped in a given sector. A possible way out was introduced by Lüscher and Schaefer using open boundary condition in the time extent. However, this solution cannot be used for thermal simulations, where the time direction is required to be periodic. In this proceedings, we present results obtained using open boundary conditions in space, at non-zero temperature. With these conditions, the topological charge is not quantized and the topological barriers are lifted. A downside of this method are the strong finite-size effects introduced by the boundary conditions. We also present some exploratory results which show how these conditions could be used on an algorithmic level to reshuffle the system and generate periodic configurations with non-zero topological charge.

  11. Thermal Simulations, Open Boundary Conditions and Switches

    Directory of Open Access Journals (Sweden)

    Burnier Yannis

    2018-01-01

    Full Text Available SU(N gauge theories on compact spaces have a non-trivial vacuum structure characterized by a countable set of topological sectors and their topological charge. In lattice simulations, every topological sector needs to be explored a number of times which reflects its weight in the path integral. Current lattice simulations are impeded by the so-called freezing of the topological charge problem. As the continuum is approached, energy barriers between topological sectors become well defined and the simulations get trapped in a given sector. A possible way out was introduced by Lüscher and Schaefer using open boundary condition in the time extent. However, this solution cannot be used for thermal simulations, where the time direction is required to be periodic. In this proceedings, we present results obtained using open boundary conditions in space, at non-zero temperature. With these conditions, the topological charge is not quantized and the topological barriers are lifted. A downside of this method are the strong finite-size effects introduced by the boundary conditions. We also present some exploratory results which show how these conditions could be used on an algorithmic level to reshuffle the system and generate periodic configurations with non-zero topological charge.

  12. Effect of fee-for-service air-conditioning management in balancing thermal comfort and energy usage.

    Science.gov (United States)

    Chen, Chen-Peng; Hwang, Ruey-Lung; Shih, Wen-Mei

    2014-11-01

    Balancing thermal comfort with the requirement of energy conservation presents a challenge in hot and humid areas where air-conditioning (AC) is frequently used in cooling indoor air. A field survey was conducted in Taiwan to demonstrate the adaptive behaviors of occupants in relation to the use of fans and AC in a school building employing mixed-mode ventilation where AC use was managed under a fee-for-service mechanism. The patterns of using windows, fans, and AC as well as the perceptions of students toward the thermal environment were examined. The results of thermal perception evaluation in relation to the indoor thermal conditions were compared to the levels of thermal comfort predicted by the adaptive models described in the American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 55 and EN 15251 and to that of a local model for evaluating thermal adaption in naturally ventilated buildings. A thermal comfort-driven adaptive behavior model was established to illustrate the probability of fans/AC use at specific temperature and compared to the temperature threshold approach to illustrate the potential energy saving the fee-for-service mechanism provided. The findings of this study may be applied as a reference for regulating the operation of AC in school buildings of subtropical regions.

  13. Thermal conditions and functional requirements for molten fuel containment

    International Nuclear Information System (INIS)

    Kang, C.S.; Torri, A.

    1980-05-01

    This paper discusses the configuration and functional requirements for the molten fuel containment system (MFCS) in the GCFR demonstration plant design. Meltdown conditions following a loss of shutdown cooling (LOSC) accident were studied to define the core debris volume for a realistic meltdown case. Materials and thicknesses of the molten fuel container were defined. Stainless steel was chosen as the sacrificial material and magnesium oxide was chosen as the crucible material. Thermal conditions for an expected quasi-steady state were analyzed. Highlights of the functional requirements which directly affect the MFCS design are discussed

  14. Three-party quantum teleportation using thermal states in Heisenberg XX model with open boundary condition

    International Nuclear Information System (INIS)

    Bhan, Jaemi; Kwon, Younghun

    2007-01-01

    Recently Yeo showed that thermal states in Heisenberg XX model with periodic boundary condition could be used for three-party quantum teleportation. However it is hard to implement the periodic boundary condition in spin chain. So instead of imposing the periodic boundary condition, we consider open boundary condition in Heisenberg XX model and investigate the possibility of using thermal states in Heisenberg XX model with open boundary condition. Using this way, we find the best fidelity conditions to three known protocols in three-party quantum teleportation. It turns out that the best fidelity in every protocol would be 23

  15. The influence of local effects on thermal sensation under non-uniform environmental conditions — Gender differences in thermophysiology, thermal comfort and productivity during convective and radiant cooling

    DEFF Research Database (Denmark)

    Schellen, L.; Loomans, M.G.L.C.; de Wit, M.H.

    2012-01-01

    , thermal comfort and productivity in response to thermal non-uniform environmental conditions. Twenty healthy subjects (10 males and 10 females, age 20–29years) were exposed to two different experimental conditions: a convective cooling situation (CC) and a radiant cooling situation (RC). During...... the experiments physiological responses, thermal comfort and productivity were measured. The results show that under both experimental conditions the actual mean thermal sensation votes significantly differ from the PMV-index; the subjects are feeling colder than predicted. Furthermore, the females are more...... of the occupants. Non-uniform thermal conditions, which may occur due to application of high temperature cooling systems, can be responsible for discomfort. Contradictions in literature exist regarding the validity of the often used predicted mean vote (PMV) index for both genders, and the index is not intended...

  16. Outdoor thermal comfort in public space in warm-humid Guayaquil, Ecuador

    Science.gov (United States)

    Johansson, Erik; Yahia, Moohammed Wasim; Arroyo, Ivette; Bengs, Christer

    2018-03-01

    The thermal environment outdoors affects human comfort and health. Mental and physical performance is reduced at high levels of air temperature being a problem especially in tropical climates. This paper deals with human comfort in the warm-humid city of Guayaquil, Ecuador. The main aim was to examine the influence of urban micrometeorological conditions on people's subjective thermal perception and to compare it with two thermal comfort indices: the physiologically equivalent temperature (PET) and the standard effective temperature (SET*). The outdoor thermal comfort was assessed through micrometeorological measurements of air temperature, humidity, mean radiant temperature and wind speed together with a questionnaire survey consisting of 544 interviews conducted in five public places of the city during both the dry and rainy seasons. The neutral and preferred values as well as the upper comfort limits of PET and SET* were determined. For both indices, the neutral values and upper thermal comfort limits were lower during the rainy season, whereas the preferred values were higher during the rainy season. Regardless of season, the neutral values of PET and SET* are above the theoretical neutral value of each index. The results show that local people accept thermal conditions which are above acceptable comfort limits in temperate climates and that the subjective thermal perception varies within a wide range. It is clear, however, that the majority of the people in Guayaquil experience the outdoor thermal environment during daytime as too warm, and therefore, it is important to promote an urban design which creates shade and ventilation.

  17. Application of 13C and 15N stable isotope probing to characterize RDX degrading microbial communities under different electron-accepting conditions

    International Nuclear Information System (INIS)

    Cho, Kun-Ching; Lee, Do Gyun; Fuller, Mark E.; Hatzinger, Paul B.; Condee, Charles W.; Chu, Kung-Hui

    2015-01-01

    Highlights: • SIP characterized RDX-degrading communities under different e-accepting conditions. • Dominant RDX degradation pathways differed under different e-accepting conditions. • More complete detoxification of RDX occurred under methanogenic and sulfate-reducing conditions than under manganese(IV) and iron(III)-reducing conditions. - Abstract: This study identified microorganisms capable of using the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) or its metabolites as carbon and/or nitrogen sources under different electron-accepting conditions using 13 C and 15 N stable isotope probing (SIP). Mesocosms were constructed using groundwater and aquifer solids from an RDX-contaminated aquifer. The mesocosms received succinate as a carbon source and one of four electron acceptors (nitrate, manganese(IV), iron(III), or sulfate) or no additional electron acceptor (to stimulate methanogenesis). When RDX degradation was observed, subsamples from each mesocosm were removed and amended with 13 C 3 - or ring- 15 N 3 -, nitro- 15 N 3 -, or fully-labeled 15 N 6 -RDX, followed by additional incubation and isolation of labeled nucleic acids. A total of fifteen 16S rRNA sequences, clustering in α- and γ-Proteobacteria, Clostridia, and Actinobacteria, were detected in the 13 C-DNA fractions. A total of twenty seven sequences were derived from different 15 N-DNA fractions, with the sequences clustered in α- and γ-Proteobacteria, and Clostridia. Interestingly, sequences identified as Desulfosporosinus sp. (in the Clostridia) were not only observed to incorporate the labeled 13 C or 15 N from labeled RDX, but also were detected under each of the different electron-accepting conditions. The data suggest that 13 C- and 15 N-SIP can be used to characterize microbial communities involved in RDX biodegradation, and that the dominant pathway of RDX biodegradation may differ under different electron-accepting conditions

  18. A Novel 3D Thermal Impedance Model for High Power Modules Considering Multi-layer Thermal Coupling and Different Heating/Cooling Conditions

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2015-01-01

    accurate temperature estimation either vertically or horizontally inside the power devices is still hard to identify. This paper investigates the thermal behavior of high power module in various operating conditions by means of Finite Element Method (FEM). A novel 3D thermal impedance network considering......Thermal management of power electronic devices is essential for reliable performance especially at high power levels. One of the most important activities in the thermal management and reliability improvement is acquiring the temperature information in critical points of the power module. However...

  19. Field study of thermal comfort in non-air-conditioned buildings in a tropical island climate.

    Science.gov (United States)

    Lu, Shilei; Pang, Bo; Qi, Yunfang; Fang, Kun

    2018-01-01

    The unique geographical location of Hainan makes its climate characteristics different from inland areas in China. The thermal comfort of Hainan also owes its uniqueness to its tropical island climate. In the past decades, there have been very few studies on thermal comfort of the residents in tropical island areas in China. A thermal environment test for different types of buildings in Hainan and a thermal comfort field investigation of 1944 subjects were conducted over a period of about two months. The results of the survey data show that a high humidity environment did not have a significant impact on human comfort. The neutral temperature for the residents in tropical island areas was 26.1 °C, and the acceptable temperature range of thermal comfort was from 23.1 °C to 29.1 °C. Residents living in tropical island areas showed higher heat resistance capacity, but lower cold tolerance than predicted. The neutral temperature for females (26.3 °C) was higher than for males (25.8 °C). Additionally, females were more sensitive to air temperature than males. The research conclusions can play a guiding role in the thermal environment design of green buildings in Hainan Province. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Mathematical model for thermal and entropy analysis of thermal solar collectors by using Maxwell nanofluids with slip conditions, thermal radiation and variable thermal conductivity

    Science.gov (United States)

    Aziz, Asim; Jamshed, Wasim; Aziz, Taha

    2018-04-01

    In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The non-Newtonian Maxwell nanofluid model is utilized for the working fluid along with slip and convective boundary conditions and comprehensive analysis of entropy generation in the system is also observed. The effect of thermal radiation and variable thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for Cu-water and TiO2-water nanofluids. Results are presented for the velocity, temperature and entropy generation profiles, skin friction coefficient and Nusselt number. The discussion is concluded on the effect of various governing parameters on the motion, temperature variation, entropy generation, velocity gradient and the rate of heat transfer at the boundary.

  1. Thermal comfort study of hospital workers in Malaysia.

    Science.gov (United States)

    Yau, Y H; Chew, B T

    2009-12-01

    This article presents findings of the thermal comfort study in hospitals. A field survey was conducted to investigate the temperature range for thermal comfort in hospitals in the tropics. Thermal acceptability assessment was conducted to examine whether the hospitals in the tropics met the ASHRAE Standard-55 80% acceptability criteria. A total of 114 occupants in four hospitals were involved in the study. The results of the field study revealed that only 44% of the examined locations met the comfort criteria specified in ASHRAE Standard 55. The survey also examined the predicted percentage of dissatisfied in the hospitals. The results showed that 49% of the occupants were satisfied with the thermal environments in the hospitals. The field survey analysis revealed that the neutral temperature for Malaysian hospitals was 26.4 degrees C. The comfort temperature range that satisfied 90% of the occupants in the space was in the range of 25.3-28.2 degrees C. The results from the field study suggested that a higher comfort temperature was required for Malaysians in hospital environments compared with the temperature criteria specified in ASHRAE Standard (2003). In addition, the significant deviation between actual mean vote and predicted mean vote (PMV) strongly implied that PMV could not be applied without errors in hospitals in the tropics. The new findings on thermal comfort temperature range in hospitals in the tropics could be used as an important guide for building services engineers and researchers who are intending to minimize energy usage in heating, ventilating and air conditioning systems in hospitals operating in the tropics with acceptable thermal comfort level and to improve the performance and well-being of its workers.

  2. Evaluation of thermal comfort in university classrooms through objective approach and subjective preference analysis.

    Science.gov (United States)

    Nico, Maria Anna; Liuzzi, Stefania; Stefanizzi, Pietro

    2015-05-01

    Assessing thermal comfort becomes more relevant when the aim is to maximise learning and productivity performances, as typically occurs in offices and schools. However, if, in the offices, the Fanger model well represents the thermal occupant response, then on the contrary, in schools, adaptive mechanisms significantly influence the occupants' thermal preference. In this study, an experimental approach was performed in the Polytechnic University of Bari, during the first days of March, in free running conditions. First, the results of questionnaires were compared according to the application of the Fanger model and the adaptive model; second, using a subjective scale, a complete analysis was performed on thermal preference in terms of acceptability, neutrality and preference, with particular focus on the influence of gender. The user possibility to control the indoor plant system produced a significant impact on the thermal sensation and the acceptability of the thermal environment. Gender was also demonstrated to greatly influence the thermal judgement of the thermal environment when an outdoor cold climate occurs. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  3. Identification of complex model thermal boundary conditions based on exterior temperature measurement

    International Nuclear Information System (INIS)

    Lu Jianming; Ouyang Guangyao; Zhang Ping; Rong Bojun

    2012-01-01

    Combining the advantages of the finite element software in temperature field analyzing with the multivariate function optimization arithmetic, a feasibility method based on the exterior temperature was proposed to get the thermal boundary conditions, which was required in temperature field analyzing. The thermal boundary conditions can be obtained only by some temperature measurement values. Taking the identification of the convection heat transfer coefficient of a high power density diesel engine cylinder head as an example, the calculation result shows that when the temperature measurement error was less than 0.5℃, the maximum relative error was less than 2%. It is shown that the new method was feasible (authors)

  4. INDOOR THERMAL CONDITION OF FACTORY BUILDING IN BANGLADESH

    OpenAIRE

    Muhammed Abdullah Al Sayem Khan; Mohd. Hamdan Ahmad; Tareef Hayat Khan

    2011-01-01

    Bangladesh is a developing country and has a lot of factories for different products for local use and also export to abroad. Garments industries are one of the top most items of exported items. A huge number of populations are working in garments industries. But these factories are not well designed in sense of the thermal environment. Workers experiences sickness related to indoor environment. The productions of these factories are affected due to employees’ health condition. The research i...

  5. Experimental study of human thermal sensation under hypobaric conditions in winter clothes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haiying; Hu, Songtao; Liu, Guodan [Department of Environment and Municipal Engineering, Qingdao Technological University, Qingdao (China); Li, Angui [Department of Environment and Municipal Engineering, Xi' an University of Architecture and Technology, Xi' an (China)

    2010-11-15

    Hypobaric conditions, with pressures about 20-30% below that at sea level, are often experienced at mountain resorts and plateau areas. The diffusive transfer of water evaporation increases at hypobaric conditions whereas dry heat loss by convection decreases. In order to clarify the effects of barometric on human thermal comfort, experiments are conducted in a decompression chamber where the air parameters were controllable. During experiments, air temperature is set at a constant of 20, air velocity is controlled at <0.1 m/s, 0.2 m/s, 0.25 m/s, and 0.3 m/s by stages. The barometric condition is examined stepwise for 1atm, 0.85 atm and 0.75 atm of simulated hypobaric conditions, which is equivalent to altitude of 0 m, 1300 m, and 2300 m respectively. Ten males and ten females in winter clothes participate in the experiments. Thermal sensations are measured with ASHRAE seven-point rating scales and skin temperatures were tested at each altitude. The main results are as follows: when the altitude rises, (1) the mean thermal sensation drops; (2) people become more sensitive to draught and expect lower air movements; (3) no significant change of mean skin temperature has been found. The results of the present study indicate that hypobaric environment tends to make people feel cooler. (author)

  6. The Impact of Listening Condition on Background Noise Acceptance for Young Adults with Normal Hearing

    Science.gov (United States)

    Gordon-Hickey, Susan; Moore, Robert E.; Estis, Julie M.

    2012-01-01

    Purpose: To evaluate the effect of different speech conditions on background noise acceptance. A total of 23 stimulus pairings, differing in primary talker gender (female, male, conventional), number of background talkers (1, 4, 12), and gender composition of the background noise (female, male, mixed) were used to evaluate background noise…

  7. Thermal conditions and perceived air quality in an air-conditioned auditorium

    Science.gov (United States)

    Polednik, Bernard; Guz, Łukasz; Skwarczyński, Mariusz; Dudzińska, Marzenna R.

    2016-07-01

    The study reports measurements of indoor air temperature (T) and relative humidity (RH), perceived air quality (PAQ) and CO2, fine aerosol particle number (PN) and mass (PM1) concentrations in an air conditioned auditorium. The measurements of these air physical parameters have been carried out in the unoccupied auditorium with the air conditioning system switched off (AC off mode) and in the unoccupied and occupied auditorium with the air conditioning system switched off during the night and switched on during the day (AC on/off mode). The average indoor air thermal parameters, CO2 concentration and the PAQ value (in decipols) were elevated, while average PM1 concentration was lower in the AC on/off mode. A statistically significant (p PAQ values and CO2 concentrations (r = 0.66 and r = 0.59, respectively) in that AC mode. A significant negative correlation has been observed between T and PN and PM1 concentrations (r = -0.38 and r = -0.49, respectively). In the AC off mode the above relations between T and the particle concentrations were not that unequivocal. These findings may be of importance as they indicate that in certain AC operation modes the indoor air quality deteriorates along with the variation of the indoor air microclimate and room occupation. This, in turn, may adversely affect the comfort and productivity of the users of air conditioned premises.

  8. Thermodynamic model of a thermal storage air conditioning system with dynamic behavior

    International Nuclear Information System (INIS)

    Fleming, Evan; Wen, Shaoyi; Shi, Li; Silva, Alexandre K. da

    2013-01-01

    Highlights: • We developed an automotive thermal storage air conditioning system model. • The thermal storage unit utilizes phase change materials. • We use semi-analytic solution to the coupled phase change and forced convection. • We model the airside heat exchange using the NTU method. • The system model can incorporate dynamic inputs, e.g. variable inlet airflow. - Abstract: A thermodynamic model was developed to predict transient behavior of a thermal storage system, using phase change materials (PCMs), for a novel electric vehicle climate conditioning application. The main objectives of the paper are to consider the system’s dynamic behavior, such as a dynamic air flow rate into the vehicle’s cabin, and to characterize the transient heat transfer process between the thermal storage unit and the vehicle’s cabin, while still maintaining accurate solution to the complex phase change heat transfer. The system studied consists of a heat transfer fluid circulating between either of the on-board hot and cold thermal storage units, which we refer to as thermal batteries, and a liquid–air heat exchanger that provides heat exchange with the incoming air to the vehicle cabin. Each thermal battery is a shell-and-tube configuration where a heat transfer fluid flows through parallel tubes, which are surrounded by PCM within a larger shell. The system model incorporates computationally inexpensive semi-analytic solution to the conjugated laminar forced convection and phase change problem within the battery and accounts for airside heat exchange using the Number of Transfer Units (NTUs) method for the liquid–air heat exchanger. Using this approach, we are able to obtain an accurate solution to the complex heat transfer problem within the battery while also incorporating the impact of the airside heat transfer on the overall system performance. The implemented model was benchmarked against a numerical study for a melting process and against full system

  9. Predicting thermal reference conditions for USA streams and rivers

    Science.gov (United States)

    Hill, Ryan A.; Hawkins, Charles P.; Carlisle, Daren M.

    2013-01-01

    Temperature is a primary driver of the structure and function of stream ecosystems. However, the lack of stream temperature (ST) data for the vast majority of streams and rivers severely compromises our ability to describe patterns of thermal variation among streams, test hypotheses regarding the effects of temperature on macroecological patterns, and assess the effects of altered STs on ecological resources. Our goal was to develop empirical models that could: 1) quantify the effects of stream and watershed alteration (SWA) on STs, and 2) accurately and precisely predict natural (i.e., reference condition) STs in conterminous USA streams and rivers. We modeled 3 ecologically important elements of the thermal regime: mean summer, mean winter, and mean annual ST. To build reference-condition models (RCMs), we used daily mean ST data obtained from several thousand US Geological Survey temperature sites distributed across the conterminous USA and iteratively modeled ST with Random Forests to identify sites in reference condition. We first created a set of dirty models (DMs) that related STs to both natural factors (e.g., climate, watershed area, topography) and measures of SWA, i.e., reservoirs, urbanization, and agriculture. The 3 models performed well (r2 = 0.84–0.94, residual mean square error [RMSE] = 1.2–2.0°C). For each DM, we used partial dependence plots to identify SWA thresholds below which response in ST was minimal. We then used data from only the sites with upstream SWA below these thresholds to build RCMs with only natural factors as predictors (r2 = 0.87–0.95, RMSE = 1.1–1.9°C). Use of only reference-quality sites caused RCMs to suffer modest loss of predictor space and spatial coverage, but this loss was associated with parts of ST response curves that were flat and, therefore, not responsive to further variation in predictor space. We then compared predictions made with the RCMs to predictions made with the DMs with SWA set to 0. For most

  10. Influence of thermal conditioning media on Charpy specimen test temperature

    International Nuclear Information System (INIS)

    Nanstad, R.K.; Swain, R.L.; Berggren, R.G.

    1989-01-01

    The Charpy V-notch (CVN) impact test is used extensively for determining the toughness of structural materials. Research programs in many technologies concerned with structural integrity perform such testing to obtain Charpy energy vs temperature curves. American Society for Testing and Materials Method E 23 includes rather strict requirements regarding determination and control of specimen test temperature. It specifies minimum soaking times dependent on the use of liquids or gases as the medium for thermally conditioning the specimen. The method also requires that impact of the specimen occur within 5 s removal from the conditioning medium. It does not, however, provide guidance regarding choice of conditioning media. This investigation was primarily conducted to investigate the changes in specimen temperature which occur when water is used for thermal conditioning. A standard CVN impact specimen of low-alloy steel was instrumented with surface-mounted and embedded thermocouples. Dependent on the media used, the specimen was heated or cooled to selected temperatures in the range -100 to 100 degree C using cold nitrogen gas, heated air, acetone and dry ice, methanol and dry ice, heated oil, or heated water. After temperature stabilization, the specimen was removed from the conditioning medium while the temperatures were recorded four times per second from all thermocouples using a data acquisition system and a computer. The results show that evaporative cooling causes significant changes in the specimen temperatures when water is used for conditioning. Conditioning in the other media did not result in such significant changes. The results demonstrate that, even within the guidelines of E 23, significant test temperature changes can occur which may substantially affect the Charpy impact test results if water is used for temperature conditioning. 7 refs., 11 figs

  11. Examination of thermal comfort in a hospital using PMV-PPD model.

    Science.gov (United States)

    Pourshaghaghy, A; Omidvari, M

    2012-11-01

    In this study, the performance of air conditioning system and the level of thermal comfort are determined in a state hospital located in Kermanshah city in the west of Iran in winter and summer using the Predicted Mean Vote (PMV) model which has been presented by ISO-7730 (2005). The Predicted Mean Vote (PMV) and the Predicted Percentage Dissatisfied (PPD) indices were computed using the data acquired from the experimental measurements performed in the building. The results showed that the values of PMV in some parts of the building, both for men and women, are not within the standard acceptable range defined by ISO. It was found that the most thermal problems in winter occur in morning work shift, and the worst thermal conditions in summer occur in noon work shift. The t-test results revealed that there is no noticeable difference between the thermal conditions of some rooms and those of the surroundings. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  12. Evaluation of thermal perception in schoolyards under Mediterranean climate conditions

    Science.gov (United States)

    Antoniadis, D.; Katsoulas, N.; Papanastasiou, D.; Christidou, V.; Kittas, C.

    2016-03-01

    The aim of this paper was to study qualitatively and quantitatively the thermal perception and corresponding heat stress conditions that prevail in two schoolyards in a coastal city in central Greece. For this purpose, meteorological parameters (i.e., wind speed, temperature, relative humidity, solar radiation) were recorded at 70 and 55 measuring points in the schoolyards, from 14:00 to 15:30 local time, during May and June of 2011. The measuring points were distributed so as to get measurements at points (a) directly exposed to the sun, (b) under the shadow of trees and building structures, and (c) near building structures. Cluster analysis was applied to group observations and revealed places that are microclimatically homogeneous. Thermal perception and heat stress conditions were assessed by means of the physiologically equivalent temperature (PET, °C), and the results are presented in relevant charts. The impact of material's albedo, radiation's reflection by structures and obstacles, and different tree species on thermal perception and heat stress conditions was also assessed. The analysis showed that trees triggered a reduction of incident solar radiation that ranged between 79 and 94 % depending on tree's species, crown dimension, tree height, and leaf area. PET values were mainly affected by solar radiation and wind speed. Trees caused a reduction of up to 37 % in PET values, while a 1-m s-1 increase in wind speed triggered a reduction of 3.7-5.0 °C in PET value. The effective shading area in the two schoolyards was small, being 27.5 and 11 %. The results of this study could be exploited by urban planning managers when designing or improving the outdoor environment of a school complex.

  13. Mathematical model for thermal solar collectors by using magnetohydrodynamic Maxwell nanofluid with slip conditions, thermal radiation and variable thermal conductivity

    Science.gov (United States)

    Mahmood, Asif; Aziz, Asim; Jamshed, Wasim; Hussain, Sajid

    Solar energy is the cleanest, renewable and most abundant source of energy available on earth. The main use of solar energy is to heat and cool buildings, heat water and to generate electricity. There are two types of solar energy collection system, the photovoltaic systems and the solar thermal collectors. The efficiency of any solar thermal system depend on the thermophysical properties of the operating fluids and the geometry/length of the system in which fluid is flowing. In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The flow is induced by a non-uniform stretching of the porous sheet and the uniform magnetic field is applied in the transverse direction to the flow. The non-Newtonian Maxwell fluid model is utilized for the working fluid along with slip boundary conditions. Moreover the high temperature effect of thermal radiation and temperature dependent thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for cu-water and TiO2 -water nanofluids. Results are presented for the velocity and temperature profiles as well as the skin friction coefficient and Nusselt number and the discussion is concluded on the effect of various governing parameters on the motion, temperature variation, velocity gradient and the rate of heat transfer at the boundary.

  14. Effects of service condition on rolling contact fatigue failure mechanism and lifetime of thermal spray coatings—A review

    Science.gov (United States)

    Cui, Huawei; Cui, Xiufang; Wang, Haidou; Xing, Zhiguo; Jin, Guo

    2015-01-01

    The service condition determines the Rolling Contact Fatigue(RCF) failure mechanism and lifetime under ascertain material structure integrity parameter of thermal spray coating. The available literature on the RCF testing of thermal spray coatings under various condition services is considerable; it is generally difficult to synthesize all of the result to obtain a comprehensive understanding of the parameters which has a great effect on a thermal spray coating's resistance of RCF. The effects of service conditions(lubrication states, contact stresses, revolve speed, and slip ratio) on the changing of thermal spray coatings' contact fatigue lifetime is introduced systematically. The effects of different service condition on RCF failure mechanism of thermal spray coating from the change of material structure integrity are also summarized. Moreover, In order to enhance the RCF performance, the parameter optimal design formula of service condition and material structure integrity is proposed based on the effect of service condition on thermal spray coatings' contact fatigue lifetime and RCF failure mechanism. The shortage of available literature and the forecast focus in future researches are discussed based on available research. The explicit result of RCF lifetime law and parameter optimal design formula in term of lubrication states, contact stresses, revolve speed, and slip ratio, is significant to improve the RCF performance on the engineering application.

  15. Thermal science under extreme conditions. Proceedings of the annual congress of the French Society of Thermal science - SFT 2012, 29 May-1 June, Bordeaux-Talence

    International Nuclear Information System (INIS)

    Gendrhi, Philippe; Perrin, Bernard; Journeau, Christophe; MOST, Jean-Michel; Nicolai, Philippe

    2012-06-01

    This publication proposes the contributions made during plenary sessions, and those made on various themes (Multi-physical couplings combustion; Contacts and interfaces; Natural, hybrid and forced convection, Energy and the environment; High temperatures and high flows; Metrology and identification; Micro- and nano-thermal science; Radiation; Control of systems and thermal process; System thermal science; Life thermal science; Transfer in multi-phase media; Transfer in porous media). Among the plenary session conferences some authors more particularly addressed the following issues: Thermal science at the heart of thermonuclear fusion (presentation of thermonuclear fusion by magnetic confinement); Thermal science of severe accidents of nuclear reactors (study of the thermal science of corium-water interaction which could result in a thermal detonation, study of corium baths at the vessel bottom or in interaction with the vessel well concrete, proposition of technological solutions for corium recovery); Fusion by inertial confinement and associated energy exchanges (case of inertial confinement by power lasers, presentation of needed conditions to obtain an energetic gain, of different energy and heat transfers under extreme conditions)

  16. Thermal-hydraulic analysis of PWR cores in transient condition

    International Nuclear Information System (INIS)

    Silva Galetti, M.R. da.

    1984-01-01

    A calculational methodology for thermal - hydraulic analysis of PWR cores under steady-state and transient condition was selected and made available to users. An evaluation of the COBRA-IIIP/MIT code, used for subchannel analysis, was done through comparison of the code results with experimental data on steady state and transient conditions. As a result, a comparison study allowing spatial and temporal localization of critical heat flux was obtained. A sensitivity study of the simulation model to variations in some empirically determined parameter is also presented. Two transient cases from Angra I FSAR were analysed, showing the evolution of minimum DNBR with time. (Author) [pt

  17. Assessing Thermal Comfort Due to a Ventilated Double Window

    Science.gov (United States)

    Carlos, Jorge S.; Corvacho, Helena

    2017-10-01

    Building design and its components are the result of a complex process, which should provide pleasant conditions to its inhabitants. Therefore, indoor acceptable comfort is influenced by the architectural design. ISO and ASHRAE standards define thermal comfort as the condition of mind that expresses satisfaction with the thermal environment. The energy demand for heating, beside the building’s physical properties, also depend on human behaviour, like opening or closing windows. Generally, windows are the weakest façade element concerning to thermal performance. A lower thermal resistance allows higher thermal conduction through it. When a window is very hot or cold, and the occupant is very close to it, it may result in thermal discomfort. The functionality of a ventilated double window introduces new physical considerations to a traditional window. In consequence, it is necessary to study the local effect on human comfort in function of the boundary conditions. Wind, solar availability, air temperature and therefore heating and indoor air quality conditions will affect the relationship between this passive system and the indoor environment. In the present paper, the influence of thermal performance and ventilation on human comfort resulting from the construction and geometry solutions is shown, helping to choose the best solution. The presented approach shows that in order to save energy it is possible to reduce the air changes of a room to the minimum, without compromising air quality, enhancing simultaneously local thermal performance and comfort. The results of the study on the effect of two parallel windows with a ventilated channel in the same fenestration on comfort conditions for several different room dimensions, are also presented. As the room dimensions’ rate changes so does the window to floor rate; therefore, under the same climatic conditions and same construction solution, different results are obtained.

  18. Mathematical Modelling of Thermal Process to Aquatic Environment with Different Hydrometeorological Conditions

    Directory of Open Access Journals (Sweden)

    Alibek Issakhov

    2014-01-01

    Full Text Available This paper presents the mathematical model of the thermal process from thermal power plant to aquatic environment of the reservoir-cooler, which is located in the Pavlodar region, 17 Km to the north-east of Ekibastuz town. The thermal process in reservoir-cooler with different hydrometeorological conditions is considered, which is solved by three-dimensional Navier-Stokes equations and temperature equation for an incompressible flow in a stratified medium. A numerical method based on the projection method, divides the problem into three stages. At the first stage, it is assumed that the transfer of momentum occurs only by convection and diffusion. Intermediate velocity field is solved by fractional steps method. At the second stage, three-dimensional Poisson equation is solved by the Fourier method in combination with tridiagonal matrix method (Thomas algorithm. Finally, at the third stage, it is expected that the transfer is only due to the pressure gradient. Numerical method determines the basic laws of the hydrothermal processes that qualitatively and quantitatively are approximated depending on different hydrometeorological conditions.

  19. Design parameters of a non-air-conditioned cinema hall for thermal comfort under arid-zone climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, G.N. (Indian Inst. of Tech., New Delhi (India). Centre for Energy Studies); Lugani, N. (Indian Inst. of Tech., New Delhi (India). Centre for Energy Studies); Singh, A.K. (Indian Inst. of Tech., New Delhi (India). Centre for Energy Studies)

    1993-01-01

    In this communication, a design of a cinema hall suitable for climatic conditions in an arid zone has been presented. The various cooling techniques, namely evaporative cooling, wind tower, ventilation/infiltration and natural cooling, have been incorporated in the design to achieve thermal comfort during the period of operation. The design parameters have been optimized on the basis of numerical computations after establishing an energy balance for each component of a cinema hall. It is observed that cooling treatment, i.e., a wind tower with a cooling pool on the roof provides reasonable thermal comfort inside the enclosure. (orig.)

  20. Impact of building forms on thermal performance and thermal comfort conditions in religious buildings in hot climates: a case study in Sharjah city

    Science.gov (United States)

    Mushtaha, Emad; Helmy, Omar

    2017-11-01

    The common system used for thermal regulation in mosques of United Arab Emirates (UAE) is the heating, ventilating and air-conditioning (HVAC) system. This system increases demands on energy consumption and increases CO2 emission. A passive design approach is one of the measures to reduce these problems. This study involved an analytical examination of building forms, followed by testing the impact of these forms on its thermal performance and indoor thermal comfort. The tests were conducted using energy simulations software packages. Passive parameters such as shading devices, thermal insulation and natural ventilation were applied in six cases, including the baseline case within each form. The obtained results showed a significant effect of mosque forms as well as passive design techniques on the thermal comfort within the structures. The findings confirmed that the use of passive design alone would not help achieve thermal comfort, but reduce the annual energy consumption by10%. By integrating a hybrid air-conditioning system as another supporting approach, the annual energy consumption could be reduced by 67.5%, which allows for the designing of a much smaller HVAC system.

  1. PETher - Physical Properties of Thermal Water under In-situ-Conditions

    Science.gov (United States)

    Herfurth, Sarah; Schröder, Elisabeth

    2016-04-01

    The objective of PETher, a research project funded by the German Federal Ministry for Economic Affairs and Energy (BMWi), is to experimentally determine thermo-physical properties (specific isobaric heat capacity, kinematic viscosity, density and thermal conductivity) of geothermal water in-situ-conditions (pressure, temperature, chemical composition including gas content of the brine) present in geothermal applications. Knowing these thermo-physical properties reduces the uncertainties with respect to estimating the thermal output and therefore the economic viability of the power plant. Up to now, only a limited number of measurements of selected physical properties have been made, usually under laboratory conditions and for individual geothermal plants. In-situ measured parameters, especially in the temperature range of 120°C and higher, at pressures of 20 bar and higher, as well as with a salinity of up to 250 g/l, are sparse to non-existing. Therefore, pure water properties are often used as reference data and for designing the power plant and its components. Currently available numerical models describing the thermo-physical properties are typically not valid for the conditions in geothermal applications and do not consider the substantial influence of the chemical composition of the thermal water. Also, actual geothermal waters have not been subject of detailed measurements systematically performed under operational conditions on a large-scale basis. Owing to the lack of reliable data, a validation of numerical models for investigating geothermal systems is not possible. In order to determine the dependency of the thermo-physical properties of geothermal water on temperature, pressure and salinity in-situ measurements are conducted. The measurements are taking place directly at several geothermal applications located in Germany's hydrogeothermal key regions. In order to do this, a mobile testing unit was developed and refined with instruments specifically

  2. DNS, LES and RANS of turbulent heat transfer in boundary layer with suddenly changing wall thermal conditions

    International Nuclear Information System (INIS)

    Hattori, Hirofumi; Yamada, Shohei; Tanaka, Masahiro; Houra, Tomoya; Nagano, Yasutaka

    2013-01-01

    Highlights: • We study the turbulent boundary layer with heat transfer by DNS. • Turbulent boundary layers with suddenly changing wall thermal conditions are observed. • The detailed turbulent statistics and structures in turbulent thermal boundary layer are discussed. • Turbulence models in LES and RANS are evaluated using DNS results. • LES and RANS are almost in good agreement with DNS results. -- Abstract: The objectives of this study are to investigate a thermal field in a turbulent boundary layer with suddenly changing wall thermal conditions by means of direct numerical simulation (DNS), and to evaluate predictions of a turbulence model in such a thermal field, in which DNS of spatially developing boundary layers with heat transfer can be conducted using the generation of turbulent inflow data as a method. In this study, two types of wall thermal condition are investigated using DNS and predicted by large eddy simulation (LES) and Reynolds-averaged Navier–Stokes equation simulation (RANS). In the first case, the velocity boundary layer only develops in the entrance of simulation, and the flat plate is heated from the halfway point, i.e., the adiabatic wall condition is adopted in the entrance, and the entrance region of thermal field in turbulence is simulated. Then, the thermal boundary layer develops along a constant temperature wall followed by adiabatic wall. In the second case, velocity and thermal boundary layers simultaneously develop, and the wall thermal condition is changed from a constant temperature to an adiabatic wall in the downstream region. DNS results clearly show the statistics and structure of turbulent heat transfer in a constant temperature wall followed by an adiabatic wall. In the first case, the entrance region of thermal field in turbulence can be also observed. Thus, both the development and the entrance regions in thermal fields can be explored, and the effects upstream of the thermal field on the adiabatic region are

  3. General 3D Lumped Thermal Model with Various Boundary Conditions for High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2016-01-01

    Accurate thermal dynamics modeling of high power Insulated Gate Bipolar Transistor (IGBT) modules is important information for the reliability analysis and thermal design of power electronic systems. However, the existing thermal models have their limits to correctly predict these complicated...... thermal behaviors in the IGBTs. In this paper, a new three-dimensional (3D) lumped thermal model is proposed, which can easily be characterized from Finite Element Methods (FEM) based simulation and acquire the thermal distribution in critical points. Meanwhile the boundary conditions including...... the cooling system and power losses are modeled in the 3D thermal model, which can be adapted to different real field applications of power electronic converters. The accuracy of the proposed thermal model is verified by experimental results....

  4. Towards the control of car underhood thermal conditions

    International Nuclear Information System (INIS)

    Khaled, Mahmoud; Harambat, Fabien; Peerhossaini, Hassan

    2011-01-01

    The present paper reports an experimental study of the aerothermal phenomena in the vehicle underhood compartment as investigated by measuring temperature, convective heat flux, and radiative heat flux. Measurements are carried out on a passenger vehicle in wind tunnel S4 of Saint-Cyr-France. The underhood space is instrumented by 120 surface and air thermocouples and 20 fluxmeters. Measurements are performed for three thermal functioning conditions while the engine is in operation and the front wheels are positioned on the test facility with power-absorption-controlled rollers. In the thermal analysis, particular attention is given to measuring absorbed convective heat fluxes at component surfaces. It is shown that, in some components, the outside air entering the engine compartment (for cooling certain components) can in fact heat other components. This problem arises from the underhood architecture, specifically the positioning of some components downstream of warmer components in the same airflow. Optimized thermal management suggests placing these components further upstream or isolating them from the hot stream by deflectors. Given style constraints, however, the use of air deflectors is more suitable than underhood architectural changes. Much of the present paper is devoted to heat flux analysis of the specific thermal behaviours in the underhood compartment (especially the absorption of convective heat fluxes) and to a description of a new control approach exploiting air deflectors to optimize underhood aerothermal management. - Research highlights: → We present a physical analysis of particular underhood aerothermal behaviors. → In this analysis, convective heat flux absorption should be noted. → A new optimization procedure based on this physical analysis is proposed. → It entails airflow redistribution in the underhood through deflectors. → The new procedures are simple and easy to implement in the car underhood.

  5. Ability of Cu2+-montmorillonite to accept an toxic pollutants

    International Nuclear Information System (INIS)

    Janikova, V.; Jona, E.; Janik, R.; Pavlik, V.

    2015-01-01

    It is global problem that toxic pollutants are in the permanent contact to people through soil and water. Nowadays, it is important to eliminate these pollutants for future generations and to keep environment in the health condition. In relation to this article, aromatic organic compounds like benzene, phenol and aniline were chosen. These are used in various branches of industry, mainly in rubber industry or for production of dyes and in addition, phenol is commonly used in cosmetics or in food industry. Montmorillonite is clay mineral consisting of 2:1 sheets (tetrahedral:octahedral) and interlayer space where exchangeable cations and water molecules are present. Due to its structure, montmorillonite is able to accept some compounds or pollutants. This is the reason why it is mainly used as the covering material of radioactive waste in order to remove toxic pollutants. For investigation of toxic pollutants removing, XRD powder diffraction, infrared spectroscopy and thermal analysis were used. Our results show that Cu 2+ -montmorillonite is able to accept toxic benzene ring-based pollutants into interlayer. This mentioned ability can be proven on the basis of the investigation results relating to difference of interlayer distance, typical frequencies of -OH group or -NH 2 group, while these results were supplemented by thermal properties. (authors)

  6. Thermal Performance for Wet Cooling Tower with Different Layout Patterns of Fillings under Typical Crosswind Conditions

    Directory of Open Access Journals (Sweden)

    Ming Gao

    2017-01-01

    Full Text Available A thermal-state model experimental study was performed in lab to investigate the thermal performance of a wet cooling tower with different kinds of filling layout patterns under windless and 0.4 m/s crosswind conditions. In this paper, the contrast analysis was focused on comparing a uniform layout pattern and one kind of optimal non-uniform layout pattern when the environmental crosswind speed is 0 m/s and 0.4 m/s. The experimental results proved that under windless conditions, the heat transfer coefficient and total heat rejection of circulating water for the optimal non-uniform layout pattern can enhance by approximately 40% and 28%, respectively, compared with the uniform layout pattern. It was also discovered that the optimal non-uniform pattern can dramatically relieve the influence of crosswind on the thermal performance of the tower when the crosswind speed is equal to 0.4 m/s. For the uniform layout pattern, the heat transfer coefficient under 0.4 m/s crosswind conditions decreased by 9.5% compared with the windless conditions, while that value lowered only by 2.0% for the optimal non-uniform layout pattern. It has been demonstrated that the optimal non-uniform layout pattern has the better thermal performance under 0.4 m/s crosswind condition.

  7. Direct measurement of thermal conductivity in solid iron at planetary core conditions.

    Science.gov (United States)

    Konôpková, Zuzana; McWilliams, R Stewart; Gómez-Pérez, Natalia; Goncharov, Alexander F

    2016-06-02

    The conduction of heat through minerals and melts at extreme pressures and temperatures is of central importance to the evolution and dynamics of planets. In the cooling Earth's core, the thermal conductivity of iron alloys defines the adiabatic heat flux and therefore the thermal and compositional energy available to support the production of Earth's magnetic field via dynamo action. Attempts to describe thermal transport in Earth's core have been problematic, with predictions of high thermal conductivity at odds with traditional geophysical models and direct evidence for a primordial magnetic field in the rock record. Measurements of core heat transport are needed to resolve this difference. Here we present direct measurements of the thermal conductivity of solid iron at pressure and temperature conditions relevant to the cores of Mercury-sized to Earth-sized planets, using a dynamically laser-heated diamond-anvil cell. Our measurements place the thermal conductivity of Earth's core near the low end of previous estimates, at 18-44 watts per metre per kelvin. The result is in agreement with palaeomagnetic measurements indicating that Earth's geodynamo has persisted since the beginning of Earth's history, and allows for a solid inner core as old as the dynamo.

  8. Thermal power plant efficiency enhancement with Ocean Thermal Energy Conversion

    International Nuclear Information System (INIS)

    Soto, Rodrigo; Vergara, Julio

    2014-01-01

    In addition to greenhouse gas emissions, coastal thermal power plants would gain further opposition due to their heat rejection distressing the local ecosystem. Therefore, these plants need to enhance their thermal efficiency while reducing their environmental offense. In this study, a hybrid plant based on the principle of Ocean Thermal Energy Conversion was coupled to a 740 MW coal-fired power plant project located at latitude 28°S where the surface to deepwater temperature difference would not suffice for regular OTEC plants. This paper presents the thermodynamical model to assess the overall efficiency gained by adopting an ammonia Rankine cycle plus a desalinating unit, heated by the power plant condenser discharge and refrigerated by cold deep seawater. The simulation allowed us to optimize a system that would finally enhance the plant power output by 25–37 MW, depending on the season, without added emissions while reducing dramatically the water temperature at discharge and also desalinating up to 5.8 million tons per year. The supplemental equipment was sized and the specific emissions reduction was estimated. We believe that this approach would improve the acceptability of thermal and nuclear power plant projects regardless of the plant location. -- Highlights: • An Ocean Thermal Energy Conversion hybrid plant was designed. • The waste heat of a power plant was delivered as an OTEC heat source. • The effect of size and operating conditions on plant efficiency were studied. • The OTEC implementation in a Chilean thermal power plant was evaluated. • The net efficiency of the thermal power plant was increased by 1.3%

  9. Numerical simulation of diurnally varying thermal environment in a street canyon under haze-fog conditions

    Science.gov (United States)

    Tan, Zijing; Dong, Jingliang; Xiao, Yimin; Tu, Jiyuan

    2015-10-01

    The impact of haze-fog on surface temperature, flow pattern, pollutant dispersion and pedestrian thermal comfort are investigated using computational fluid dynamics (CFD) approach based on a three-dimensional street canyon model under different haze-fog conditions. In this study, light extinction coefficient (Kex) is adopted to represent haze-fog pollution level. Numerical simulations are performed for different Kex values at four representative time events (1000 LST, 1300 LST, 1600 LST and 2000 LST). The numerical results suggest that the surface temperature is strongly affected by the haze-fog condition. Surface heating induced by the solar radiation is enhanced by haze-fog, as higher surface temperature is observed under thicker haze-fog condition. Moreover, the temperature difference between sunlit and shadow surfaces is reduced, while that for the two shadow surfaces is slightly increased. Therefore, the surface temperature among street canyon facets becomes more evenly distributed under heavy haze-fog conditions. In addition, flow patterns are considerably altered by different haze-fog conditions, especially for the afternoon (1600 LST) case, in which thermal-driven flow has opposite direction as that of the wind-driven flow direction. Consequently, pollutants such as vehicular emissions will accumulate at pedestrian level, and pedestrian thermal comfort may lower under thicker haze-fog condition.

  10. Large-acceptance diamond planar refractive lenses manufactured by laser cutting.

    Science.gov (United States)

    Polikarpov, Maxim; Snigireva, Irina; Morse, John; Yunkin, Vyacheslav; Kuznetsov, Sergey; Snigirev, Anatoly

    2015-01-01

    For the first time, single-crystal diamond planar refractive lenses have been fabricated by laser micromachining in 300 µm-thick diamond plates which were grown by chemical vapour deposition. Linear lenses with apertures up to 1 mm and parabola apex radii up to 500 µm were manufactured and tested at the ESRF ID06 beamline. The large acceptance of these lenses allows them to be used as beam-conditioning elements. Owing to the unsurpassed thermal properties of single-crystal diamond, these lenses should be suitable to withstand the extreme flux densities expected at the planned fourth-generation X-ray sources.

  11. 41 CFR 102-75.1140 - What is the policy governing the acceptance or rejection of a conditional gift of real property...

    Science.gov (United States)

    2010-07-01

    ... applicable to the acceptance of gifts under the provisions of other laws. Following receipt of such... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What is the policy governing the acceptance or rejection of a conditional gift of real property for a particular defense...

  12. Influence of thermal charge preparation on coke comminution under blast-furnace operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shkoller, M.B.; Dinel' t, V.M.; Korchuganova, G.S.; Petrov, V.B.

    1983-01-01

    An investigation is described for the study of structural breakdown of coke by thermochemical action of alkali and alkaline-earth metal vapors under blast furnace operating conditions. Bench-scale test facilities are described in which a pair of coke samples are exposed to the metal vapors then subjected to gasification. Structural strength tests were performed before and after each experiment. Coke samples were obtained in either moist or thermally prepared condition. The value of thermal charge preparation (heat treatment of the coal at 150/sup 0/C in a fluidized bed) was established, since it shifts the pore size distribution to the smaller size, thereby retarding adsorption of the metal vapors. 16 references, 4 figures, 2 tables.

  13. Energy efficient hybrid nanocomposite-based cool thermal storage air conditioning system for sustainable buildings

    International Nuclear Information System (INIS)

    Parameshwaran, R.; Kalaiselvam, S.

    2013-01-01

    The quest towards energy conservative building design is increasingly popular in recent years, which has triggered greater interests in developing energy efficient systems for space cooling in buildings. In this work, energy efficient silver–titania HiTES (hybrid nanocomposites-based cool thermal energy storage) system combined with building A/C (air conditioning) system was experimentally investigated for summer and winter design conditions. HiNPCM (hybrid nanocomposite particles embedded PCM) used as the heat storage material has exhibited 7.3–58.4% of improved thermal conductivity than at its purest state. The complete freezing time for HiNPCM was reduced by 15% which was attributed to its improved thermophysical characteristics. Experimental results suggest that the effective energy redistribution capability of HiTES system has contributed for reduction in the chiller nominal cooling capacity by 46.3% and 39.6% respectively, under part load and on-peak load operating conditions. The HiTES A/C system achieved 27.3% and 32.5% of on-peak energy savings potential in summer and winter respectively compared to the conventional A/C system. For the same operating conditions, this system yield 8.3%, 12.2% and 7.2% and 10.2% of per day average and yearly energy conservation respectively. This system can be applied for year-round space conditioning application without sacrificing energy efficiency in buildings. - Highlights: • Energy storage is acquired by HiTES (hybrid nanocomposites-thermal storage) system. • Thermal conductivity of HiNPCM (hybrid nanocomposites-PCM) was improved by 58.4%. • Freezing time of HiNPCM was reduced by 15% that enabled improved energy efficiency. • Chiller nominal capacity was reduced by 46.3% and 39.6% in on-peak and part load respectively. • HiTES A/C system achieved appreciable energy savings in the range of 8.3–12.2%

  14. Effect of Material Composition and Environmental Condition on Thermal Characteristics of Conductive Asphalt Concrete

    Directory of Open Access Journals (Sweden)

    Pan Pan

    2017-02-01

    Full Text Available Conductive asphalt concrete with high thermal conductivity has been proposed to improve the solar energy collection and snow melting efficiencies of asphalt solar collector (ASC. This paper aims to provide some insight into choosing the basic materials for preparation of conductive asphalt concrete, as well as determining the evolution of thermal characteristics affected by environmental factors. The thermal properties of conductive asphalt concrete were studied by the Thermal Constants Analyzer. Experimental results showed that aggregate and conductive filler have a significant effect on the thermal properties of asphalt concrete, while the effect of asphalt binder was not evident due to its low proportion. Utilization of mineral aggregate and conductive filler with higher thermal conductivity is an efficient method to prepare conductive asphalt concrete. Moreover, change in thermal properties of asphalt concrete under different temperature and moisture conditions should be taken into account to determine the actual thermal properties of asphalt concrete. There was no noticeable difference in thermal properties of asphalt concrete before and after aging. Furthermore, freezing–thawing cycles strongly affect the thermal properties of conductive asphalt concrete, due to volume expansion and bonding degradation.

  15. DEVELOPMENT OF PROTOTYPE SYSTEM FOR REGULATING THERMAL CONDITIONS OF TELECOMMUNICATIONS EQUIPMENT CABINETS

    Directory of Open Access Journals (Sweden)

    A. T. Rashidkhanov

    2017-01-01

    Full Text Available Objectives. The main objective of the study was to regulate the thermal regime and ensure the reliability of electronic equipmentMethods. In order to conduct experimental studies of the thermoelectric cooling system using heat pipes, a stand was assembled on which the developed and manufactured prototype was studied. The object of the experimental studies was a prototype cooling system, consisting of a thermoelectric battery made of conventional unified thermoelectric materials of ICE-71 type. The solution of the research problems carried out by the method of reduction to ordinary differential equations (Kantorovich method provides acceptable accuracy for such a class of problems.Results. A design of a telecommunication equipment cabinet with a thermal management system based on the use of heat pipes and thermoelectric cooling units is proposed. A mathematical model for the determination of the thermal field in the cabinet volume is considered; an experimental stand for the prototype study is described; the results of experimental studies for various power sources of heat release are presented.Conclusion. Experimental studies confirm the operability of the developed cooling system for cabinets with telecommunication equipment; this cooling method has advantages over conventional forced or natural cooling; the temperature in the block volume and the peak values of the heat sources are significantly reduced; at dissipation powers on one board within 50 W there is no need to use special means to remove heat from hot junctions of the thermoelectric battery.

  16. Thermal conditions influence changes in body temperature induced by intragastric administration of capsaicin in mice.

    Science.gov (United States)

    Mori, Noriyuki; Urata, Tomomi; Fukuwatari, Tsutomu

    2016-08-01

    Capsaicin has been reported to have unique thermoregulatory actions. However, changes in core temperature after the administration of capsaicin are a controversial point. Therefore, we investigated the effects of environmental thermal conditions on changes in body temperature caused by capsaicin in mice. We showed that intragastric administration of 10 and 15 mg/kg capsaicin increased tail temperature and decreased colonic temperatures in the core temperature (CT)-constant and CT-decreasing conditions. In the CT-increasing condition, 15 mg/kg capsaicin increased tail temperature and decreased colonic temperature. However, 10 mg/kg capsaicin increased colonic temperature. Furthermore, the amount of increase in tail temperature was greater in the CT-decreasing condition and lower in the CT-increasing condition, compared with that of the CT-constant condition. These findings suggest that the changes in core temperature were affected by the environmental thermal conditions and that preliminary thermoregulation state might be more important than the constancy of temperature to evaluate the effects of heat diffusion and thermogensis.

  17. Characteristics of Syngas Auto-ignition at High Pressure and Low Temperature Conditions with Thermal Inhomogeneities

    KAUST Repository

    Pal, Pinaki; Mansfield, Andrew B.; Wooldridge, Margaret S.; Im, Hong G.

    2015-01-01

    Effects of thermal inhomogeneities on syngas auto-ignition at high-pressure low-temperature conditions, relevant to gas turbine operation, are investigated using detailed one-dimensional numerical simulations. Parametric tests are carried out for a range of thermodynamic conditions (T = 890-1100 K, P = 3-20 atm) and composition (Ф = 0.1, 0.5). Effects of global thermal gradients and localized thermal hot spots are studied. In the presence of a thermal gradient, the propagating reaction front transitions from spontaneous ignition to deflagration mode as the initial mean temperature decreases. The critical mean temperature separating the two distinct auto-ignition modes is computed using a predictive criterion and found to be consistent with front speed and Damkohler number analyses. The hot spot study reveals that compression heating of end-gas mixture by the propagating front is more pronounced at lower mean temperatures, significantly advancing the ignition delay. Moreover, the compression heating effect is dependent on the domain size.

  18. Characteristics of Syngas Auto-ignition at High Pressure and Low Temperature Conditions with Thermal Inhomogeneities

    KAUST Repository

    Pal, Pinaki

    2015-05-31

    Effects of thermal inhomogeneities on syngas auto-ignition at high-pressure low-temperature conditions, relevant to gas turbine operation, are investigated using detailed one-dimensional numerical simulations. Parametric tests are carried out for a range of thermodynamic conditions (T = 890-1100 K, P = 3-20 atm) and composition (Ф = 0.1, 0.5). Effects of global thermal gradients and localized thermal hot spots are studied. In the presence of a thermal gradient, the propagating reaction front transitions from spontaneous ignition to deflagration mode as the initial mean temperature decreases. The critical mean temperature separating the two distinct auto-ignition modes is computed using a predictive criterion and found to be consistent with front speed and Damkohler number analyses. The hot spot study reveals that compression heating of end-gas mixture by the propagating front is more pronounced at lower mean temperatures, significantly advancing the ignition delay. Moreover, the compression heating effect is dependent on the domain size.

  19. Comparison of different test methods to assess thermal stresses of metal oxide surge arresters under pollution conditions

    International Nuclear Information System (INIS)

    Bargigia, A.; de Nigris, M.; Pigini, A.; Sironi, A.

    1992-01-01

    The report deals with the research conducted by ENEL, the Italian Electricity Board, to assess the performance of zinc oxide surge arresters under pollution condition, with special reference to the consequent thermal stress on internal active parts which can affect the energy handling capabality of the arrester and may lead, in particular conditions, even to thermal runaway

  20. The effect of atmospheric thermal conditions and urban thermal pollution on all-cause and cardiovascular mortality in Bangladesh

    International Nuclear Information System (INIS)

    Burkart, Katrin; Schneider, Alexandra; Breitner, Susanne; Khan, Mobarak Hossain; Kraemer, Alexander; Endlicher, Wilfried

    2011-01-01

    This study assessed the effect of temperature and thermal atmospheric conditions on all-cause and cardiovascular mortality in Bangladesh. In particular, differences in the response to elevated temperatures between urban and rural areas were investigated. Generalized additive models (GAMs) for daily death counts, adjusted for trend, season, day of the month and age were separately fitted for urban and rural areas. Breakpoint models were applied for determining the increase in mortality above and below a threshold (equivalent) temperature. Generally, a 'V'-shaped (equivalent) temperature-mortality curve with increasing mortality at low and high temperatures was observed. Particularly, urban areas suffered from heat-related mortality with a steep increase above a specific threshold. This adverse heat effect may well increase with ongoing urbanization and the intensification of the urban heat island due to the densification of building structures. Moreover, rising temperatures due to climate change could aggravate thermal stress. - Highlights: → Temperature exhibits a strong influence on mortality in Bangladesh. → Mortality increases at low and high end of the temperature range. → Temperature is increased in the urban area of Dhaka, particular during summer. → Urban areas are facing increased risk of heat-related mortality. → Urbanization and climate change are likely to increase heat-related mortality. - Mortality in Bangladesh is strongly affected by thermal atmospheric conditions with particularly urban areas facing excess mortality above a specific threshold temperature.

  1. Thermal comfort assessment in civil aircraft cabins

    Directory of Open Access Journals (Sweden)

    Pang Liping

    2014-04-01

    Full Text Available Aircraft passengers are more and demanding in terms of thermal comfort. But it is not yet easy for aircraft crew to control the environment control system (ECS that satisfies the thermal comfort for most passengers due to a number of causes. This paper adopts a corrected predicted mean vote (PMV model and an adaptive model to assess the thermal comfort conditions for 31 investigated flights and draws the conclusion that there does exist an uncomfortable thermal phenomenon in civil aircraft cabins, especially in some short-haul continental flights. It is necessary to develop an easy way to predict the thermal sensation of passengers and to direct the crew to control ECS. Due to the assessment consistency of the corrected PMV model and the adaptive model, the adaptive model of thermal neutrality temperature can be used as a method to predict the cabin optimal operative temperature. Because only the mean outdoor effective temperature ET∗ of a departure city is an input variable for the adaptive model, this method can be easily understood and implemented by the crew and can satisfy 80–90% of the thermal acceptability levels of passengers.

  2. Thermodynamic model of a thermal storage air conditioning system with dynamic behavior

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, E; Wen, SY; Shi, L; da Silva, AK

    2013-12-01

    A thermodynamic model was developed to predict transient behavior of a thermal storage system, using phase change materials (PCMs), for a novel electric vehicle climate conditioning application. The main objectives of the paper are to consider the system's dynamic behavior, such as a dynamic air flow rate into the vehicle's cabin, and to characterize the transient heat transfer process between the thermal storage unit and the vehicle's cabin, while still maintaining accurate solution to the complex phase change heat transfer. The system studied consists of a heat transfer fluid circulating between either of the on-board hot and cold thermal storage units, which we refer to as thermal batteries, and a liquid-air heat exchanger that provides heat exchange with the incoming air to the vehicle cabin. Each thermal battery is a shell-and-tube configuration where a heat transfer fluid flows through parallel tubes, which are surrounded by PCM within a larger shell. The system model incorporates computationally inexpensive semianalytic solution to the conjugated laminar forced convection and phase change problem within the battery and accounts for airside heat exchange using the Number of Transfer Units (NTUs) method for the liquid-air heat exchanger. Using this approach, we are able to obtain an accurate solution to the complex heat transfer problem within the battery while also incorporating the impact of the airside heat transfer on the overall system performance. The implemented model was benchmarked against a numerical study for a melting process and against full system experimental data for solidification using paraffin wax as the PCM. Through modeling, we demonstrate the importance of capturing the airside heat exchange impact on system performance, and we investigate system response to dynamic operating conditions, e.g., air recirculation. (C) 2013 Elsevier Ltd. All rights reserved.

  3. Effect of Galleries on Thermal Conditions of Urban Open Areas

    Directory of Open Access Journals (Sweden)

    Shahab Kariminia

    2016-06-01

    Full Text Available Computer simulations were performed by ENVI-met model along with physical measurements in two urban squares under hot summer conditions in Isfahan, central Iran. Each scenario concentrated on adding or extending galleries in each square. The results confirmed the role of galleries on thermal conditions; however, it was found that the effectiveness of this strategy depends on the square geometry. It presented higher efficiency for the small square with higher H/W ratio. This solution is advisable for smaller squares and when the peripheral parts are frequently used compared to the middle areas. Galleries are most efficient when allowing enough natural ventilation.

  4. EXAMINATION OF THE SIMULATED THERMAL CONDITIONS IN A POPULAR PLAYGROUND RELATED TO THE HUMAN REACTIONS AND THE JUDGMENT OF THE AREA DESIGN

    Directory of Open Access Journals (Sweden)

    L.A. ÉGERHÁZI

    2013-03-01

    Full Text Available In the field of urban bioclimatology an important and timely research direction today is to examine the thermal conditions of public places. In our study, human thermal comfort analysis was performed in a modern and well-attended children playground located in Szeged (Hungary. The aim of the paper is to reveal the changes in the thermal comfort conditions between two seasons and also the resulting subjective thermal reactions of visitors in this relatively small area. Thermal comfort conditions were quantified by the Physiologically Equivalent Temperature (PET. For typical summer and autumn days of 2011 numerical simulations of thermal comfort conditions in the playground were carried out by means of the urban microclimate model ENVI-met. Spatial distribution of the simulated PET, i.e. thermal stress maps were created in two different times of the selected days in order to characterize the distinct microclimatological conditions appearing in the area. The relationship between the momentary spatial patterns of visitors and the thermal conditions was also under investigation. Additionally, onsite questionnaire survey was implemented which highlights the people’s subjective evaluation related to the design of the playground.

  5. Validation of the thermal balance of Laguna Verde turbine under conditions of extended power increase

    International Nuclear Information System (INIS)

    Castaneda G, M. A.; Cruz B, H. J.; Mercado V, J. J.; Cardenas J, J. B.; Garcia de la C, F. M.

    2012-10-01

    The present work is a continuation of the task: Modeling of the vapor cycle of Laguna Verde with the PEPSE code to conditions of thermal power licensed at present (2027 MWt) in which the modeling of the vapor cycle of the nuclear power plant of Laguna Verde was realized with PEPSE code (Performance Evaluation of Power System Efficiencies). Once reached the conditions of nominal operation of extended power increase, operating both units to 2371 MWt; after the tests phase of starting-up and operation is necessary to carry out a verification of the proposed design of the vapor cycle for the new operation conditions. All this, having in consideration that the vapor cycle designer only knows the detail of the prospective performance of the main turbine, for all the other components (for example pumps, heat inter changers, valves, reactor, humidity separators and re-heaters, condensers, etc.) makes generic suppositions based on engineering judgment. This way carries out the calculations of thermal balance to determine the guaranteed gross power. The purpose of the present work is to comment the detail of the validation carried out of the specific thermal balance (thermal kit) of the nuclear power plant, making use of the design characteristics of the different components that conform the vapor cycle. (Author)

  6. Effects of Urban Configuration on Human Thermal Conditions in a Typical Tropical African Coastal City

    Directory of Open Access Journals (Sweden)

    Emmanuel Lubango Ndetto

    2013-01-01

    Full Text Available A long-term simulation of urban climate was done using the easily available long-term meteorological data from a nearby synoptic station in a tropical coastal city of Dar es Salaam, Tanzania. The study aimed at determining the effects of buildings’ height and street orientations on human thermal conditions at pedestrian level. The urban configuration was represented by a typical urban street and a small urban park near the seaside. The simulations were conducted in the microscale applied climate model of RayMan, and results were interpreted in terms of the thermal comfort parameters of mean radiant (Tmrt and physiologically equivalent (PET temperatures. PET values, high as 34°C, are observed to prevail during the afternoons especially in the east-west oriented streets, and buildings’ height of 5 m has less effect on the thermal comfort. The optimal reduction of Tmrt and PET values for pedestrians was observed on the nearly north-south reoriented streets and with increased buildings’ height especially close to 100 m. Likewise, buildings close to the park enhance comfort conditions in the park through additional shadow. The study provides design implications and management of open spaces like urban parks in cities for the sake of improving thermal comfort conditions for pedestrians.

  7. Automatic Traffic Data Collection under Varying Lighting and Temperature Conditions in Multimodal Environments: Thermal versus Visible Spectrum Video-Based Systems

    Directory of Open Access Journals (Sweden)

    Ting Fu

    2017-01-01

    Full Text Available Vision-based monitoring systems using visible spectrum (regular video cameras can complement or substitute conventional sensors and provide rich positional and classification data. Although new camera technologies, including thermal video sensors, may improve the performance of digital video-based sensors, their performance under various conditions has rarely been evaluated at multimodal facilities. The purpose of this research is to integrate existing computer vision methods for automated data collection and evaluate the detection, classification, and speed measurement performance of thermal video sensors under varying lighting and temperature conditions. Thermal and regular video data was collected simultaneously under different conditions across multiple sites. Although the regular video sensor narrowly outperformed the thermal sensor during daytime, the performance of the thermal sensor is significantly better for low visibility and shadow conditions, particularly for pedestrians and cyclists. Retraining the algorithm on thermal data yielded an improvement in the global accuracy of 48%. Thermal speed measurements were consistently more accurate than for the regular video at daytime and nighttime. Thermal video is insensitive to lighting interference and pavement temperature, solves issues associated with visible light cameras for traffic data collection, and offers other benefits such as privacy, insensitivity to glare, storage space, and lower processing requirements.

  8. 20 CFR 703.207 - Kinds of negotiable securities that may be deposited; conditions of deposit; acceptance of deposits.

    Science.gov (United States)

    2010-04-01

    ... amount fixed by the Office under the regulations in this part shall deposit any negotiable securities... deposited; conditions of deposit; acceptance of deposits. 703.207 Section 703.207 Employees' Benefits... AND RELATED STATUTES INSURANCE REGULATIONS Insurance Carrier Security Deposit Requirements § 703.207...

  9. Differences between young adults and elderly in thermal comfort, productivity, and thermal physiology in response to a moderate temperature drift and a steady-state condition

    NARCIS (Netherlands)

    Schellen, L.; Marken Lichtenbelt, van W.D.; Loomans, M.G.L.C.; Toftum, J.; Wit, de M.H.

    2010-01-01

    Results from naturally ventilated buildings show that allowing the indoor temperature to drift does not necessarily result in thermal discomfort and may allow for a reduction in energy use. However, for stationary conditions, several studies indicate that the thermal neutral temperature and optimum

  10. A real time study on condition monitoring of distribution transformer using thermal imager

    Science.gov (United States)

    Mariprasath, T.; Kirubakaran, V.

    2018-05-01

    The transformer is one of the critical apparatus in the power system. At any cost, a few minutes of outages harshly influence the power system. Hence, prevention-based maintenance technique is very essential. The continuous conditioning and monitoring technology significantly increases the life span of the transformer, as well as reduces the maintenance cost. Hence, conditioning and monitoring of transformer's temperature are very essential. In this paper, a critical review has been made on various conditioning and monitoring techniques. Furthermore, a new method, hot spot indication technique, is discussed. Also, transformer's operating condition is monitored by using thermal imager. From the thermal analysis, it is inferred that major hotspot locations are appearing at connection lead out; also, the bushing of the transformer is the very hottest spot in transformer, so monitoring the level of oil is essential. Alongside, real time power quality analysis has been carried out using the power analyzer. It shows that industrial drives are injecting current harmonics to the distribution network, which causes the power quality problem on the grid. Moreover, the current harmonic limit has exceeded the IEEE standard limit. Hence, the adequate harmonics suppression technique is need an hour.

  11. Experimental analysis of the thermal entrainment factor of air curtains in vertical open display cabinets for different ambient air conditions

    International Nuclear Information System (INIS)

    Gaspar, Pedro Dinis; Carrilho Goncalves, L.C.; Pitarma, R.A.

    2011-01-01

    The vertical open refrigerated display cabinets suffer alterations of their thermal performance and energy efficiency due to variations of ambient air conditions. The air curtain provides an aerothermodynamics insulation effect that can be evaluated by the thermal entrainment factor calculation as an engineering approximation or by the calculus of all sensible and latent thermal loads. This study presents the variation of heat transfer rate and thermal entrainment factor obtained through experimental tests carried out for different ambient air conditions, varying air temperature, relative humidity, velocity and its direction relatively to the display cabinet frontal opening. The thermal entrainment factor are analysed and compared with the total sensible and latent heats results for the experimental tests. From an engineering point of view, it is concluded that thermal entrainment factor cannot be used indiscriminately, although its use is suitable to design better cabinet under the same climate class condition.

  12. Stochastic Estimation Methods for Induction Motor Transient Thermal Monitoring Under Non Linear Condition

    Directory of Open Access Journals (Sweden)

    Mellah HACEN

    2012-08-01

    Full Text Available The induction machine, because of its robustness and low-cost, is commonly used in the industry. Nevertheless, as every type of electrical machine, this machine suffers of some limitations. The most important one is the working temperature which is the dimensioning parameter for the definition of the nominal working point and the machine lifetime. Due to a strong demand concerning thermal monitoring methods appeared in the industry sector. In this context, the adding of temperature sensors is not acceptable and the studied methods tend to use sensorless approaches such as observators or parameters estimators like the extended Kalman Filter (EKF. Then the important criteria are reliability, computational cost ad real time implementation.

  13. The role of waste package specifications as a forerunner to ILW repository conditions for acceptance

    International Nuclear Information System (INIS)

    Barlow, S.V.; Palmer, J.D.

    1998-01-01

    In the absence of a finalized repository site, design or associated safety case, Nirex is not in a position to issue conditions for acceptance. Nirex has therefore developed a strategy which facilitates packaging of intermediate level waste by providing guidance through waste package specifications, supported by the formal assessment of specific packaging proposals on a case-by-case basis. The waste package specifications are comprehensive and cover all aspects of the waste package including dimensions and other key features, performance standards, wasteform, quality assurance, and data recording requirements. The waste package specifications will be subject to periodic review as repository design and safety cases are finalized and will progressively become site- and design-specific. The waste package specifications will eventually form the basis for conditions for acceptance. The strategy described in this paper has been successfully followed by Nirex and customers for the past ten years and has permitted wastes to be packaged for a deep repository with confidence in the absence of a finalized site and safety cases for the repository. Because the process has its basis in a generic repository concept, it remains robust, despite the increased uncertainty following the March 1997 Secretary of State's decision, as to the siting and time-scale of a deep waste repository, and continues to be an important component of the UK's waste management strategy. (author)

  14. Classification of radioactive waste and determination of waste specifications as well as conditions of acceptance for ultimate storage

    International Nuclear Information System (INIS)

    Merz, E.

    1983-04-01

    The determination of waste specification and conditions of acceptance must follow a certain scheme, the basics of which will be presented. First the types of waste and the ultimate storage facilities will be characterized. The various categories of waste will be listed in a universally valid system, and the preliminary conditioning options will be determined. Based on the results of safety analysis taking into account the whole system - geological circumstances, ultimate store mines, types and forms of waste - specifications for the various ultimate store products are to be derived following iterative methods. Suggestions though not of a binding nature and probably subject to eventual revisions in part will be presented. To ensure the safety goals, i.e. the exclusion of radioactivity from the human biosphere, appropriate quality control is required concerning the production and the acceptance at the ultimate store. The guiding principles to be heeded will be discussed in brief. (orig./HP) [de

  15. Thermal design of a modern, air-conditioned, single-floor, solar-powered desert house

    KAUST Repository

    Serag-Eldin, M. A.

    2011-01-01

    The paper presents a thermal analysis of a single-floor, solar-powered desert house. The house is air-conditioned and provides all modern comforts and facilities. Electrical power, which drives the entire energy system, is generated by roof

  16. Use of local convective and radiant cooling at warm environment: effect on thermal comfort and perceived air quality

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Duszyk, Marcin; Krejcirikova, Barbora

    2012-01-01

    The effect of four local cooling devices (convective, radiant and combined) on thermal comfort and perceived air quality reported by 24 subjects at 28 ˚C and 50% RH was studied. The devices studied were: (1) desk cooling fan, (2) personalized ventilation providing clean air, (3) two radiant panels...... and (4) two radiant panels with one panel equipped with small fans. A reference condition without cooling was tested as well. The response of the subjects to the exposed conditions was collected by computerized questionnaires. The cooling devices significantly (pthermal comfort...... compared to without cooling. The acceptability of the thermal environment was similar for all cooling devices. The acceptability of air movement and PAQ increased when the local cooling methods were used. The best results were achieved with personalized ventilation and cooling fan. The improvement in PAQ...

  17. Thermal Behavior of Aerospace Spur Gears in Normal and Loss-of-Lubrication Conditions

    Science.gov (United States)

    Handschuh, Robert F.

    2015-01-01

    Testing of instrumented spur gears operating at aerospace rotorcraft conditions was conducted. The instrumented gears were operated in a normal and in a loss-of-lubrication environment. Thermocouples were utilized to measure the temperature at various locations on the test gears and a test utilized a full-field, high-speed infrared thermal imaging system. Data from thermocouples was recorded during all testing at 1 hertz. One test had the gears shrouded and a second test was run without the shrouds to permit the infrared thermal imaging system to take data during loss-of-lubrication operation. Both tests using instrumented spur gears were run in normal and loss-of-lubrication conditions. Also the result from four other loss-of-lubrication tests will be presented. In these tests two different torque levels were used while operating at the same rotational speed (10000 revolutions per minute).

  18. Cerebral cortex classification by conditional random fields applied to intraoperative thermal imaging

    Directory of Open Access Journals (Sweden)

    Hoffmann Nico

    2016-09-01

    Full Text Available Intraoperative thermal neuroimaging is a novel intraoperative imaging technique for the characterization of perfusion disorders, neural activity and other pathological changes of the brain. It bases on the correlation of (sub-cortical metabolism and perfusion with the emitted heat of the cortical surface. In order to minimize required computational resources and prevent unwanted artefacts in subsequent data analysis workflows foreground detection is a important preprocessing technique to differentiate pixels representing the cerebral cortex from background objects. We propose an efficient classification framework that integrates characteristic dynamic thermal behaviour into this classification task to include additional discriminative features. The first stage of our framework consists of learning this representation of characteristic thermal time-frequency behaviour. This representation models latent interconnections in the time-frequency domain that cover specific, yet a priori unknown, thermal properties of the cortex. In a second stage these features are then used to classify each pixel’s state with conditional random fields. We quantitatively evaluate several approaches to learning high-level features and their impact to the overall prediction accuracy. The introduction of high-level features leads to a significant accuracy improvement compared to a baseline classifier.

  19. Analysis Thermal Comfort Condition in Complex Residential Building, Case Study: Chiangmai, Thailand

    Science.gov (United States)

    Juangjandee, Warangkana

    2017-10-01

    Due to the increasing need for complex residential buildings, it appears that people migrate into the high-density urban areas because the infrastructural facilities can be easily found in the modern metropolitan areas. Such rapid growth of urbanization creates congested residential buildings obstructing solar radiation and wind flow, whereas most urban residents spend 80-90% of their time indoor. Furthermore, the buildings were mostly built with average materials and construction detail. This causes high humidity condition for tenants that could promote mould growth. This study aims to analyse thermal comfort condition in complex residential building, Thailand for finding the passive solution to improve indoor air quality and respond to local conditions. The research methodology will be in two folds: 1) surveying on case study 2) analysis for finding the passive solution of reducing humidity indoor air The result of the survey indicated that the building need to find passive solution for solving humidity problem, that can be divided into two ways which raising ventilation and indoor temperature including increasing wind-flow ventilation and adjusting thermal temperature, for example; improving building design and stack driven ventilation. For raising indoor temperature or increasing mean radiant temperature, daylight can be passive solution for complex residential design for reducing humidity and enhance illumination indoor space simultaneous.

  20. Thermal conditions in selected urban and semi-natural habitats, important for the forensic entomology.

    Science.gov (United States)

    Michalski, Marek; Nadolski, Jerzy

    2018-06-01

    A long-term study on thermal conditions in selected urban and semi-natural habitats, where human corpses are likely to be found, was conducted in the city of Lodz (Central Poland). Thermal data were collected during two years at nine sites and compared with corresponding data from the nearest permanent meteorological station at Lodz Airport (ICAO code: EPLL). The conditions closest to those at the meteorological station prevailed in the deciduous forest, coefficient of determination R 2 for those sets of data was above 0.96. The open field was characterized by high daily amplitudes, especially during spring, while the site in the allotment gardens was characterized by relatively high winter temperatures. The conditions prevailing in all closed space sites were very diverse and only slightly similar to the external ones. The most distinct site was an unheated basement in a tenement house, where temperature was almost always above 0°C and daily amplitudes were negligible. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. EXAMINATION OF THE SIMULATED THERMAL CONDITIONS IN A POPULAR PLAYGROUND RELATED TO THE HUMAN REACTIONS AND THE JUDGMENT OF THE AREA DESIGN

    OpenAIRE

    L.A. ÉGERHÁZI; A. KOVÁCS; N. KÁNTOR; J. UNGER

    2013-01-01

    In the field of urban bioclimatology an important and timely research direction today is to examine the thermal conditions of public places. In our study, human thermal comfort analysis was performed in a modern and well-attended children playground located in Szeged (Hungary). The aim of the paper is to reveal the changes in the thermal comfort conditions between two seasons and also the resulting subjective thermal reactions of visitors in this relatively small area. Thermal comfort conditi...

  2. Variability of thermal and precipitation conditions in the growing season in Poland in the years 1966-2015

    Science.gov (United States)

    Tomczyk, Arkadiusz M.; Szyga-Pluta, Katarzyna

    2018-03-01

    The aim of the study was to identify the thermal and precipitation conditions and their changes in the growing season in Poland in the years 1966-2015. Data on average daily air temperature and daily precipitation totals for 30 stations from the period of 1966-2015 were used. The data were obtained from the collections of the Institute of Meteorology and Water Management—National Research Institute. The growing season was defined as the period of average daily air temperature ≥ 5 °C. The mathematical formulas proposed by Gumiński (1948) were used to determine its start and end dates. In the growing season in Poland in the years 1966-2015, there were more significant changes in the thermal conditions than there were in the precipitation conditions. In terms of long-term trends over the study period, thermal conditions during the growing season are characterised by an increase in mean air temperature, an increase in the sum of air temperatures and an increasing occurrence of seasons classified as above-normal seasons. Precipitation conditions of the growing season show large temporal and spatial variations in precipitation and a predominance of normal conditions. The changes in precipitation were not statistically significant, except for Świnoujście.

  3. Investigation on the asymmetry of thermal condition and grain defect formation in the customary directional solidification process

    International Nuclear Information System (INIS)

    Ma, D; Wu, Q; Hollad, S; Bührig-Polaczek, A

    2012-01-01

    In the present study, the non-uniformity of the thermal condition and the corresponding grain defect formation in the customary Bridgman process were investigated. The casting clusters in radial alignment were directionally solidified in a Bridgman furnace. It was found that in the casting cluster, the shadow side facing the central rod was ineffectively heated in the hot zone and ineffectively cooled in the cooling zone during withdrawal, compared with the heater side facing the furnace heater. The metallographic examination of the simplified turbine blades exhibited that the platforms on the shadow side are very prone to stray grain formation, while the heater side reveals a markedly lower tendency for that. The asymmetric thermal condition causes the asymmetrical formation of these grain defects. This non-uniformity of the thermal condition should be minimized as far as possible, in order to effectively optimize the quality of the SC superalloy components.

  4. Solar Thermal | Climate Neutral Research Campuses | NREL

    Science.gov (United States)

    building can still be designed and constructed to be solar ready with roof exposures and slopes that accept Solar Thermal Solar Thermal Solar thermal applications can be simple, cost effective, and diverse for research campuses. The following links go to sections that describe when and where solar thermal

  5. Measured versus calculated thermal conductivity of high-grade metamorphic rocks – inferences on the thermal properties of the lower crust at ambient and in-situ conditions

    DEFF Research Database (Denmark)

    Ray, Labani; Förster, Hans-Jürgen; Förster, Andrea

    in the literature are applied. Thus, if appropriate samples (in terms of sample size or physical-chemical-mechanical condition) for laboratory measurement are not available, bulk TC of high-grade metamorphic rocks with low anisotropy and porosity could be satisfactorily good assessed from modal mineralogy, using......The bulk thermal conductivity (TC) of 26 rock samples representing felsic, intermediate and mafic granulites, from the Southern Granulite Province, India, is measured at dry and saturated conditions with the optical-scanning method. Thermal conductivity is also calculated from modal mineralogy...... (determined by XRD and EPMA), applying mixing models commonly used in thermal studies. Most rocks are fine- to medium -grained equigranular in texture. All samples are isotropic to weakly anisotropic and possess low porosities (

  6. Hypothetical accident conditions, free drop and thermal tests: Specification 6M

    International Nuclear Information System (INIS)

    Blankenship, R.W.

    1980-05-01

    The 30 gallon Specification 6M shipping container with rolled-top food pack cans as inner containers is evaluated under conditions required by 10 CFR 71.42. One kilogram of depleted uranium as UO 2 was packaged in each of the inner containers. After completion of a free drop test and a simulated thermal test, the maximum observed leakage of UO 2 for the following week was 3.2 μg. This leakage is well below the allowable leakage per week for most plutonium isotopic mixtures. Using the examples provided, any plutonium isotopic mixture can be easily compared with the allowable leakage per week. Test conditions and results are reported

  7. Evaluation of the Acceptance of Audience Response System by Corporations Using the Technology Acceptance Model

    Science.gov (United States)

    Chu, Hsing-Hui; Lu, Ta-Jung; Wann, Jong-Wen

    The purpose of this research is to explore enterprises' acceptance of Audience Response System (ARS) using Technology Acceptance Model (TAM). The findings show that (1) IT characteristics and facilitating conditions could be external variables of TAM. (2) The degree of E-business has positive significant correlation with behavioral intention of employees. (3) TAM is a good model to predict and explain IT acceptance. (4) Demographic variables, industry and firm characteristics have no significant correlation with ARS acceptance. The results provide useful information to managers and ARS providers that (1) ARS providers should focus more on creating different usages to enhance interactivity and employees' using intention. (2) Managers should pay attention to build sound internal facilitating conditions for introducing IT. (3) According to the degree of E-business, managers should set up strategic stages of introducing IT. (4) Providers should increase product promotion and also leverage academic and government to promote ARS.

  8. Consideration of loading conditions initiated by thermal transients in PWR pressure vessels

    International Nuclear Information System (INIS)

    Azodi; Glahn; Kersting; Schulz; Jansky.

    1983-01-01

    This report describes the present state of PWR-plants in the Federal Republic of Germany with respect to - the design of the primary pressure boundary - the analysis of thermal transients and resulting loads - the material conditions and neutron fluence - the requirements for protection against fast fracture. The experimental and analytical research and development programs are delineated together with some foreign R and D programs. It is shown that the parameters investigated (loading condition, crack shape and orientation etc.) cover a broad range. Extensive analytical investigations are emphasized. (orig./RW) [de

  9. In-Pile thermal fatigue of First Wall mock-ups under ITER relevant conditions

    International Nuclear Information System (INIS)

    Blom, F.; Schmalz, F.; Kamer, S.; Ketema, D.J.

    2006-01-01

    The objective of this study is to perform in-pile thermal fatigue testing of three actively cooled First Wall (FW) mock-ups to check the effect of neutron irradiation on the Be/CuCrZr joints under representative FW operation conditions. Three FW mock-ups with Beryllium armor tiles will be neutron irradiated at 1 dpa (in Be) with parallel thermal fatigue testing for 30,000 cycles. The temperatures, stress distributions and stress amplitudes at the Be/CuCrZr interface of the mock-ups will be as close as possible to the values calculated for ITER FW panels. For this objective the PWM mocks-up subjected to thermal fatigue will be integrated with high density (W) plates on the Be-side to provide heat flux by nuclear heating. The assembly will be placed in the pool-side facility of the HFR and thermal cycling is then arranged by mechanical movement towards and from the core box. As the thermal design of the irradiation rig is very critical a pilot-irradiation will be performed to cross check the models used in the thermal design of the rig. The project is currently in the design phase of both the pilot and actual irradiation rig. The irradiation of the actual rig is planned to start at mid 2007 and last for two years. (author)

  10. Cognitive Appraisals Affect Both Embodiment of Thermal Sensation and Its Mapping to Thermal Evaluation.

    Science.gov (United States)

    Keeling, Trevor P; Roesch, Etienne B; Clements-Croome, Derek

    2016-01-01

    The physical environment leads to a thermal sensation that is perceived and appraised by occupants. The present study focuses on the relationship between sensation and evaluation. We asked 166 people to recall a thermal event from their recent past. They were then asked how they evaluated this experience in terms of 10 different emotions (frustrated, resigned, dislike, indifferent, angry, anxious, liking, joyful, regretful, proud). We tested whether four psychological factors (appraisal dimensions) could be used to predict the ensuing emotions, as well as comfort, acceptability, and sensation. The four dimensions were: the Conduciveness of the event, who/what caused the event (Causality), who had control (Agency), and whether the event was expected (Expectations). These dimensions, except for Expectations, were good predictors of the reported emotions. Expectations, however, predicted the reported thermal sensation, its acceptability, and ensuing comfort. The more expected an event was, the more uncomfortable a person felt, and the less likely they reported a neutral thermal sensation. Together, these results support an embodied view of how subjective appraisals affect thermal experience. Overall, we show that appraisal dimensions mediate occupants' evaluation of their thermal sensation, which suggests an additional method for understanding psychological adaption.

  11. Thermo-active building systems and sound absorbers: Thermal comfort under real operation conditions

    DEFF Research Database (Denmark)

    Köhler, Benjamin; Rage, Nils; Chigot, Pierre

    2018-01-01

    Radiant systems are established today and have a high ecological potential in buildings while ensuring thermal comfort. Free-hanging sound absorbers are commonly used for room acoustic control, but can reduce the heat exchange when suspended under an active slab. The aim of this study...... is to evaluate the impact on thermal comfort of horizontal and vertical free-hanging porous sound absorbers placed in rooms of a building cooled by Thermo-Active Building System (TABS), under real operation conditions. A design comparing five different ceiling coverage ratios and two room types has been...... implemented during three measurement periods. A clear correlation between increase of ceiling coverage ratio and reduction of thermal comfort could not be derived systematically for each measurement period and room type, contrarily to what was expected from literature. In the first two monitoring periods...

  12. Combined photovoltaic and solar-thermal systems: overcoming barriers to market acceptance

    International Nuclear Information System (INIS)

    Collins, M.R.

    2005-01-01

    Combined Photovoltaic and Solar-Thermal Systems (PV/T Systems) combine Photovoltaic (PV) and solar thermal technologies into one system with both electrical and thermal energy output. PV/T systems have several perceived advantages to stand-alone PV or solar-thermal systems. The increased efficiency and dual nature of the systems make suitable for situations where installation space is limited, and for homeowners who are forced to decide between meeting thermal or electrical needs. The financial benefit of the combined system is also significant, as the long payback of PV systems is joined with a relatively short payback of solar thermal systems. A background of PV/T was presented, with details of classifications and the International Energy Association's program to evaluate the technical status of PV/T systems and formulate a roadmap for future development. It was noted that input from the Solar Heating and Cooling Program (SHCP) is needed to help identify market barriers in PV/T systems. This paper reviewed existing and potential PV/T systems and their technical status, and reported on the methodology established by IEA group 35. The systems were grouped according to thermal collector types of unglazed water collectors, glazed water collectors, unglazed air collectors, glazed air collectors, air-flow windows, and concentrating collectors. It was noted that a number of new systems are currently being developed, including concentrating collectors with water and air heating, unglazed air heating systems, and unglazed water heating systems. It was noted that apart from technical barriers, efficient design and performance prediction are also problematic, as tools for predicting performance do not exist. The same tools will be used to optimize PV/T system designs. It was suggested that standardized reporting methods, simulation and sizing tools and demonstration products need to be created and that regional certification issues need to be identified. Environmental

  13. Thermal performance evaluation of a massive brick wall under real weather conditions via the Conduction Transfer function method

    Directory of Open Access Journals (Sweden)

    Emilio Sassine

    2017-12-01

    Full Text Available The reliable estimation of buildings energy needs for cooling and heating is essential for any eventual thermal improvement of the envelope or the HVAC equipment. This paper presents an interesting method to evaluate the thermal performance of a massive wall by using the frequency-domain regression (FDR method to calculate CTF coefficients by means of the Fourier transform. The method is based on the EN ISO 13786 (2007 procedure by using the Taylor expansion for the elements of the heat matrix. Numerical results were validated through an experimental heating box with stochastic boundary conditions on one side of the wall representing real weather conditions and constant temperature profile on the other side representing the inside ambiance in real cases. Finally, a frequency analysis was performed in order to assess the validity and accuracy of the method used. The results show that development to the second order is sufficient to predict the thermal behavior of the studied massive wall in the range of frequencies encountered in the building applications (one hour time step. This method is useful for thermal transfer analysis in real weather conditions where the outside temperature is stochastic; it also allows the evaluation of the thermal performance of a wall through a frequency analysis.

  14. Effects of different brewing conditions on catechin content and sensory acceptance in Turkish green tea infusions.

    Science.gov (United States)

    Saklar, Sena; Ertas, Erdal; Ozdemir, Ibrahim S; Karadeniz, Bulent

    2015-10-01

    The optimal brewing conditions for Turkish green tea were determined on the basis of extracted catechins and sensory attributes. Green tea infusions were prepared at 75, 85 and 95 °C with brewing times of 1, 2, 3, 5, 10, 20, 30 and 45 min. The amounts of epistructured catechins (EGCG, EGC, ECG, EC), non-epistructured catechins (C, GC, GCG) and caffeine in brewed tea samples were analysed. Sensory analyses were performed by nine trained panelists for infusion colour, taste, aroma and overall acceptability. Brewing at 85 °C for 3 min was found to be the optimal condition, where the EGCG content was at a maximum of 50.69 mg/100 ml with the highest sensory scores. It was observed that the yield of epistructured catechins increased rapidly for the first 3-5 min of brewing at 85 °C, and increased brewing time resulted in a decrease in the yield of epistructured catechins. The amount of nonepistructured catechins continued to increase with longer extraction times. Sensory scores for infusion colour, taste, aroma and overall acceptability were highest at 3 and 5 min brewing times at all temperatures. Sensory scores were very low for 30 and 45 min brewing at 85 and 95 °C due to the bitter taste and dark colour.

  15. Thermal hydraulic conditions inducing incipient cracking in the 900 MWe unit 93 D reactor coolant pump shafts

    International Nuclear Information System (INIS)

    Bore, C.

    1995-01-01

    From 1987, 900 MWe plant operating feedback revealed cracking in the lower part of the reactor coolant pump shafts, beneath the thermal ring. Metallurgical examinations established that this was due to a thermal fatigue phenomenon known as thermal crazing, occurring after a large number of cycles. Analysis of thermal hydraulic conditions initiating the cracks does not allow exact quantification of the thermal load inducing cracking. Only qualitative analyses are thus possible, the first of which, undertaken by the pump manufacturer, Jeumont Industrie, showed that the cracks could not be due to the major transients (stop-start, injection cut-off), which were too few in number. Another explanation was then put forward: the thermal ring, shrunk onto the shaft it is required to protect against thermal shocks, loosens to allow an alternating downflow of cold water from the shaft seals and an upflow of hot water from the primary system. However, approximate calculations showed that the flow involved would be too slight to initiate the cracking observed. A more stringent analysis undertaken with the 2D flow analysis code MELODIE subsequently refuted the possibility of alternating flows beneath the ring establishing that only a hot water upflow occurred due to a 'viscosity pump' phenomenon. Crack initiation was finally considered to be due to flowrate variations beneath the ring, with the associated temperature fluctuations. This flowrate fluctuation could be due to an unidentified transient phenomenon or to a variation in pump operating conditions. This analysis of the hydraulic conditions initiating the cracks disregards shaft surface residual stresses. These are tensile stresses and show that loads less penalizing than those initially retained could cause incipient cracking. Thermal ring modifications to reduce these risks were proposed and implemented. In addition, final metallurgical treatment of the shafts was altered and implemented. In addition, final metallurgical

  16. Fracture appraisal of large scale glass block under various realistic thermal conditions

    International Nuclear Information System (INIS)

    Laude, F.; Vernaz, E.; Saint-Gaudens, M.

    1982-06-01

    Fracturing of nuclear waste glass caused primarily by thermal and residual stresses during cooling increases the potential leaching surface area and the number of small particles. A theoretical study shows that it is possible to calculate the stresses created but it is difficult to evaluate the state of fracture. Theoretical results are completed by an experimental study with inactive industrial scale glass blocks. The critical stages of its thermal history are simulated and the total surface area of the pieces is measured by comparison of leaching rate of the fractured glass with known samples in the same conditions. Quenching due to water impact, air cooling in a storage fit and experimental reassembly of fractured glass by re-heating are examined

  17. Development of RETRAN-03/MOV code for thermal-hydraulic analysis of nuclear reactor under moving conditions

    International Nuclear Information System (INIS)

    Kim, Hak Jae; Park, Goon Cherl

    1996-01-01

    Nuclear ship reactors have several; features different from land-based PWR's. Especially, effects of ship motions on reactor thermal-hydraulics and good load following capability for abrupt load changes are essential characteristics of nuclear ship reactors. This study modified the RETRAN-03 to analyze the thermal-hydraulic transients under three-dimensional ship motions, named RETRAN-03/MOV in order to apply to future marine reactors. First Japanese nuclear ship MUTSU reactor have been analyzed under various ship motions to verify this code. Calculations have been performed under rolling,heaving and stationary inclination conditions during normal operation. Also, the natural circulation has been analyzed, which can provide the decay heat removed to ensure the passive safety of marine reactors. As results, typical thermal-hydraulic characteristics of marine reactors such as flow rate oscillations and S/G water level oscillations have been successfully simulated at various conditions. 7 refs., 11 figs. (author)

  18. Energy managemant through PCM based thermal storage system for building air-conditioning: Tidel Park, Chennai

    International Nuclear Information System (INIS)

    Nallusamy, N.; Sampath, S.; Velraj, R.

    2006-01-01

    Many modern building are designed for air-conditioning and the amount of electrical energy required for providing air-conditioning can be very significant especially in the tropics. Conservation of energy is major concern to improve the overall efficiency of the system. Integration is energy storage with the conventional system gives a lot of potential for energy saving and long-term economics. Thermal energy storage systems can improve energy management and help in matching supply and demand patterns. In the present work, a detailed study has been done on the existing thermal energy storage system used in the air-conditioning system in Tidel Park, Chennai. The present study focuses on the cool energy storage system. The modes of operation and advantages of such a system for energy management are highlighted. The reason for the adoption of combined storage system and the size of the storage medium in the air-conditioning plant are analyzed. The possibility of using this concept in other cooling and heating applications, such as storage type solar water heating system, has been explored

  19. Modeling of composite synthesis in conditions of controlled thermal explosion

    Science.gov (United States)

    Kukta, Yaroslav; Knyazeva, Anna

    2017-12-01

    The paper proposes the model for the titanium-based composite synthesis from powders of titanium and carbon of non-stoichiometric composition. The model takes into account the mixture heating from chamber walls, the dependence of liquidus and solidus temperatures on the composition of reacting mixture and the formation of possible irreversible phases. The reaction retardation by the reaction product is taken into consideration in kinetic laws. As an example, the results of temperature and conversion level calculation are presented for the system Ti-C with the summary reaction for different temperatures of chamber walls heating. It was revealed that the reaction retardation being the reaction product can be the cause of incomplete conversion in the thermal explosion conditions. Non-stoichiometric composition leads to the conditions of degenerated mode when some additional heating is necessary to complete the reaction.

  20. Thermal Transport and Entropy Production Mechanisms in a Turbulent Round Jet at Supercritical Thermodynamic Conditions

    Directory of Open Access Journals (Sweden)

    Florian Ries

    2017-08-01

    Full Text Available In the present paper, thermal transport and entropy production mechanisms in a turbulent round jet of compressed nitrogen at supercritical thermodynamic conditions are investigated using a direct numerical simulation. First, thermal transport and its contribution to the mixture formation along with the anisotropy of heat fluxes and temperature scales are examined. Secondly, the entropy production rates during thermofluid processes evolving in the supercritical flow are investigated in order to identify the causes of irreversibilities and to display advantageous locations of handling along with the process regimes favorable to mixing. Thereby, it turned out that (1 the jet disintegration process consists of four main stages under supercritical conditions (potential core, separation, pseudo-boiling, turbulent mixing, (2 causes of irreversibilities are primarily due to heat transport and thermodynamic effects rather than turbulence dynamics and (3 heat fluxes and temperature scales appear anisotropic even at the smallest scales, which implies that anisotropic thermal diffusivity models might be appropriate in the context of both Reynolds-averaged Navier–Stokes (RANS and large eddy simulation (LES approaches while numerically modeling supercritical fluid flows.

  1. 14. Thermal management in the electrified propulsion; 14. Thermomanagement im elektrifizierten Antrieb

    Energy Technology Data Exchange (ETDEWEB)

    Wiebelt, Achim; Wawzyniak, Markus [Behr GmbH und Co. KG, Stuttgart (Germany)

    2013-07-15

    In conventional vehicles powered by an internal combustion engine, the thermal management usually is considered related with improvements in efficiency and the after-treatment of exhaust gas. New challenges come along due to the electrification of the drive train. Firstly, the temperature-sensitive lithium-ion battery must be cooled to the target temperature. This requires a connection of the battery cooling to the air conditioning of the vehicle. On the other side, the air conditionings in the summer as well as especially the interior heating in the winter are demanding in the design of those systems. With increasing electrification of the drive train, the required power of the drive train has to be provided by the battery more and more. This reduces the range of the electric vehicle. These thermal management systems have to operate as efficiently as possible. However, the air conditioning is not only to be seen in terms of air conditioning and thus in terms of customer acceptance, but also in terms of safety aspects. In winter, the windows must be kept free of ice and condensation as rapidly and permanently as possible. Because of the pleasant air-conditioned passenger compartment of vehicles, the so-called thermal stress for drivers is reduced in the summer thus promoting the driver's concentration.

  2. Numerical simulation of time-dependent deformations under hygral and thermal transient conditions

    International Nuclear Information System (INIS)

    Roelfstra, P.E.

    1987-01-01

    Some basic concepts of numerical simulation of the formation of the microstructure of HCP are outlined. The aim is to replace arbitrary terms like aging by more realistic terms like bond density in the xerogel and bonds between hydrating particles of HCP. Actual state parameters such as temperature, humidity and degree of hydration can be determined under transient hygral and thermal conditions by solving numerically a series of appropriate coupled differential equations with given boundary conditions. Shrinkage of a composite structure without crack formation, based on calculated moisture distributions, has been determined with numerical concrete codes. The influence of crack formation, tensile strain-hardening and softening on the total deformation of a quasi-homogeneous drying material has been studied by means of model based on FEM. The difference between shrinkage without crack formation and shrinkage with crack formation can be quantified. Drying shrinkage and creep of concrete cannot be separated. The total deformation depends on the superimposed stress fields. Transient hygral deformation can be realistically predicted if the concept of point properties is applied rigorously. Transient thermal deformation has to be dealt with in the same way. (orig./HP)

  3. A dynamic model for air-based photovoltaic thermal systems working under real operating conditions

    International Nuclear Information System (INIS)

    Sohel, M. Imroz; Ma, Zhenjun; Cooper, Paul; Adams, Jamie; Scott, Robert

    2014-01-01

    Highlights: • A dynamic model suitable for air-based photovoltaic thermal (PVT) systems is presented. • The model is validated with PVT data from two unique buildings. • The simulated output variables match very well with the experimental data. • The performance of the PVT system under changing working condition is analysed. - Abstract: In this paper a dynamic model suitable for simulating real operating conditions of air-based photovoltaic thermal (PVT) systems is presented. The performance of the model is validated by using the operational data collected from the building integrated photovoltaic (PVT) systems installed in two unique buildings. The modelled air outlet temperature and electrical power match very well with the experimental data. In Solar Decathlon house PVT, the average (RMS) error in air outlet temperatures was 4.2%. The average (RMS) error in electrical power was also 4.2%. In the Sustainable Buildings Research Centre PVT, the average errors (RMS) of PV and air temperatures were 3.8% and 2.2%, respectively. The performance of the PVT system under changing working condition is also analysed in this paper. The analysis includes the effect of ambient air temperature, air inlet temperature, air flow rate and solar irradiation on thermal, electrical, first law and second law efficiencies. Both the thermal and the 1st law efficiencies almost linearly increased with the increase of the ambient temperature. However, the PVT electrical efficiency and the second law efficiency decreased with the increase of the ambient temperature. All efficiencies expect the second law efficiency decreased with increase of the PVT air inlet temperature. The second law efficiency first increased and then reduced. With increasing the air flow rate all the efficiencies increased. The electrical and second law efficiencies become less sensitive when the air flow rate exceeded 300 l/s. Both the thermal and the 1st law efficiencies decreased while the electrical

  4. Thermal energy recovery of air conditioning system--heat recovery system calculation and phase change materials development

    International Nuclear Information System (INIS)

    Gu Zhaolin; Liu Hongjuan; Li Yun

    2004-01-01

    Latent heat thermal energy storage systems can be used to recover the rejected heat from air conditioning systems, which can be used to generate low-temperature hot water. It decreases not only the consumption of primary energy for heating domestic hot water but also the calefaction to the surroundings due to the rejection of heat from air conditioning systems. A recovery system using phase change materials (PCMs) to store the rejected (sensible and condensation) heat from air conditioning system has been developed and studied, making up the shortage of other sensible heat storage system. Also, PCMs compliant for heat recovery of air conditioning system should be developed. Technical grade paraffin wax has been discussed in this paper in order to develop a paraffin wax based PCM for the recovery of rejected heat from air conditioning systems. The thermal properties of technical grade paraffin wax and the mixtures of paraffin wax with lauric acid and with liquid paraffin (paraffin oil) are investigated and discussed, including volume expansion during the phase change process, the freezing point and the heat of fusion

  5. Do sex, body size and reproductive condition influence the thermal preferences of a large lizard? A study in Tupinambis merianae.

    Science.gov (United States)

    Cecchetto, Nicolas Rodolfo; Naretto, Sergio

    2015-10-01

    Body temperature is a key factor in physiological processes, influencing lizard performances; and life history traits are expected to generate variability of thermal preferences in different individuals. Gender, body size and reproductive condition may impose specific requirements on preferred body temperatures. If these three factors have different physiological functions and thermal requirements, then the preferred temperature may represent a compromise that optimizes these physiological functions. Therefore, the body temperatures that lizards select in a controlled environment may reflect a temperature that maximizes their physiological needs. The tegu lizard Tupinambis merianae is one of the largest lizards in South America and has wide ontogenetic variation in body size and sexual dimorphism. In the present study we evaluate intraspecific variability of thermal preferences of T. merianae. We determined the selected body temperature and the rate at which males and females attain their selected temperature, in relation to body size and reproductive condition. We also compared the behavior in the thermal gradient between males and females and between reproductive condition of individuals. Our study show that T. merianae selected body temperature within a narrow range of temperatures variation in the laboratory thermal gradient, with 36.24±1.49°C being the preferred temperature. We observed no significant differences between sex, body size and reproductive condition in thermal preferences. Accordingly, we suggest that the evaluated categories of T. merianae have similar thermal requirements. Males showed higher rates to obtain heat than females and reproductive females, higher rates than non-reproductive ones females. Moreover, males and reproductive females showed a more dynamic behavior in the thermal gradient. Therefore, even though they achieve the same selected temperature, they do it differentially. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Monitoring Thermal Performance of Hollow Bricks with Different Cavity Fillers in Difference Climate Conditions

    Science.gov (United States)

    Pavlík, Zbyšek; Jerman, Miloš; Fořt, Jan; Černý, Robert

    2015-03-01

    Hollow brick blocks have found widespread use in the building industry during the last decades. The increasing requirements to the thermal insulation properties of building envelopes given by the national standards in Europe led the brick producers to reduce the production of common solid bricks. Brick blocks with more or less complex systems of internal cavities replaced the traditional bricks and became dominant on the building ceramics market. However, contrary to the solid bricks where the thermal conductivity can easily be measured by standard methods, the complex geometry of hollow brick blocks makes the application of common techniques impossible. In this paper, a steady-state technique utilizing a system of two climatic chambers separated by a connecting tunnel for sample positioning is used for the determination of the thermal conductivity, thermal resistance, and thermal transmittance ( U value) of hollow bricks with the cavities filled by air, two different types of mineral wool, polystyrene balls, and foam polyurethane. The particular brick block is provided with the necessary temperature- and heat-flux sensors and thermally insulated in the tunnel. In the climatic chambers, different temperatures are set. After steady-state conditions are established in the measuring system, the effective thermal properties of the brick block are calculated using the measured data. Experimental results show that the best results are achieved with hydrophilic mineral wool as a cavity filler; the worst performance exhibits the brick block with air-filled cavities.

  7. Nuclear power plant accident simulations of gasket materials under simultaneous radiation plus thermal plus mechanical stress conditions

    International Nuclear Information System (INIS)

    Gillen, K.T.; Malone, G.M.

    1997-07-01

    In order to probe the response of silicone door gasket materials to a postulated severe accident in an Italian nuclear power plant, compression stress relaxation (CSR) and compression set (CS) measurements were conducted under combined radiation (approximately 6 kGy/h) and temperature (up to 230 degrees C) conditions. By making some reasonable initial assumptions, simplified constant temperature and dose rates were derived that should do a reasonable job of simulating the complex environments for worst-case severe events that combine overall aging plus accidents. Further simplification coupled with thermal-only experiments allowed us to derive thermal-only conditions that can be used to achieve CSR and CS responses similar to those expected from the combined environments that are more difficult to simulate. Although the thermal-only simulations should lead to sealing forces similar to those expected during a severe accident, modulus and density results indicate that significant differences in underlying chemistry are expected for the thermal-only and the combined environment simulations. 15 refs., 31 figs., 15 tabs

  8. Development of Boundary Condition Independent Reduced Order Thermal Models using Proper Orthogonal Decomposition

    Science.gov (United States)

    Raghupathy, Arun; Ghia, Karman; Ghia, Urmila

    2008-11-01

    Compact Thermal Models (CTM) to represent IC packages has been traditionally developed using the DELPHI-based (DEvelopment of Libraries of PHysical models for an Integrated design) methodology. The drawbacks of this method are presented, and an alternative method is proposed. A reduced-order model that provides the complete thermal information accurately with less computational resources can be effectively used in system level simulations. Proper Orthogonal Decomposition (POD), a statistical method, can be used to reduce the order of the degree of freedom or variables of the computations for such a problem. POD along with the Galerkin projection allows us to create reduced-order models that reproduce the characteristics of the system with a considerable reduction in computational resources while maintaining a high level of accuracy. The goal of this work is to show that this method can be applied to obtain a boundary condition independent reduced-order thermal model for complex components. The methodology is applied to the 1D transient heat equation.

  9. Thermal properties of nuclear matter under the periodic boundary condition

    International Nuclear Information System (INIS)

    Otuka, Naohiko; Ohnishi, Akira

    1999-01-01

    We present the thermal properties of nuclear matter under the periodic boundary condition by the use of our hadronic nucleus-nucleus cascade model (HANDEL) which is developed to treat relativistic heavy-ion collisions from BNL-AGS to CERN-SPS. We first show some results of p-p scattering calculation in our new version which is improved in order to treat isospin ratio and multiplicity more accurately. We then display the results of calculation of nuclear matter with baryon density ρ b = 0.77 fm 3 at some energy densities. Time evolution of particle abundance and temperature are shown. (author)

  10. Temperature and Thermal Expansion Analysis of the Cooling Roller Based on the Variable Heat Flux Boundary Condition

    Science.gov (United States)

    Li, Yongkang; Yang, Yang; He, Changyan

    2018-06-01

    Planar flow casting (PFC) is a primary method for preparing an amorphous ribbon. The qualities of the amorphous ribbon are significantly influenced by the temperature and thermal expansion of the cooling roller. This study proposes a new approach to analyze the three-dimensional temperature and thermal expansion of the cooling roller using variable heat flux that acted on the cooling roller as a boundary condition. First, a simplified two-dimensional model of the PFC is developed to simulate the distribution of the heat flux in the circumferential direction with the software FLUENT. The resulting heat flux is extended to be three-dimensional in the ribbon's width direction. Then, the extended heat flux is imported as the boundary condition by the CFX Expression Language, and the transient temperature of the cooling roller is analyzed in the CFX software. Next, the transient thermal expansion of the cooling roller is simulated through the thermal-structural coupling method. Simulation results show that the roller's temperature and expansion are unevenly distributed, reach the peak value in the middle width direction, and the quasi-steady state of the maximum temperature and thermal expansion are achieved after approximately 50 s and 150 s of casting, respectively. The minimum values of the temperature and expansion are achieved when the roller has a thickness of 45 mm. Finally, the reliability of the approach proposed is verified by measuring the roller's thermal expansion on the spot. This study provides theoretical guidance for the roller's thermal expansion prediction and the gap adjustment in the PFC.

  11. Thermal processing of conditioned waste and fuel substitutes; Thermische Behandlung vorbehandelter Abfaelle und Ersatzbrennstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Velden, F. van der; Engweiler, J. [Von Roll Umwelttechnik AG, Zurich (Switzerland)

    1998-12-31

    Different technologies for the thermal processing of mechanical-biologically conditioned waste are described and compared in terms of cost and flexibility. (orig.) [Deutsch] Es werden verschiedene Technologien der thermischen Behandlung mechanisch-biologisch vorbehandelter Abfaelle vorgestellt und im Hinblick auf Kosten und Flexibilitaet verglichen. (orig.)

  12. Expression for the thermal H-mode energy confinement time under ELM-free conditions

    International Nuclear Information System (INIS)

    Ryter, F.; Gruber, O.; Kardaun, O.J.W.F.; Menzler, H.P.; Wagner, F.; Schissel, D.P.; DeBoo, J.C.; Kaye, S.M.

    1992-07-01

    The design of future tokamaks, which are supposed to reach ignition with the H-mode, requires a reliable scaling expression for the H-mode energy confinement time. In the present work, an H-mode scaling expression for the thermal plasma energy confinement time has been developed by combining data from four existing divertor tokamaks, ASDEX, DIII-D, JET and PBX-M. The plasma conditions, which were as similar as possible to ensure a coherent set of data, were ELM-free deuterium discharges heated by deuterium neutral beam injection. By combining four tokamaks, the parametric dependence of the thermal energy confinement on the main plasma parameters, including the three main geometrical variables, was determined. (orig./WL)

  13. Pressurized Thermal Shock Analysis for OPR1000 Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, P. K.; Shamim, J. A.; Gairola, A.; Suh, Kune Y. [Seoul National Univ., Seoul (Korea, Republic of)

    2014-10-15

    The study provides a brief understanding of the analysis procedure and techniques using ANSYS, such as the acceptance criteria, selection and categorization of events, thermal analysis, structural analysis including fracture mechanics assessment, crack propagation and evaluation of material properties. PTS may result from instrumentation and control malfunction, inadvertent steam dump, and postulated accidents such as smallbreak (SB) LOCA, large-break (LB) LOCA, main steam line break (MSLB), feedwater line breaks and steam generator overfill. In this study our main focus is to consider only the LB LOCA due to a cold leg break of the Optimized Power Reactor 1000 MWe (OPR1000). Consideration is given as well to the emergency core cooling system (ECCS) specific sequence with the operating parameters like pressure, temperature and time sequences. The static structural and thermal analysis to investigate the effects of PTS on RPV is the main motivation of this study. Specific surface crack effects and its propagation is also considered to measure the integrity of the RPV. This study describes the procedure for pressurized thermal shock analysis due to a loss of coolant accidental condition and emergency core cooling system operation for reactor pressure vessel.. Different accidental events that cause pressurized thermal shock to nuclear RPV that can also be analyzed in the same way. Considering the limitations of low speed computer only the static analysis is conducted. The modified LBLOCA phases and simplified geometry can is utilized to analyze the effect of PTS on RPV for general understanding not for specific specialized purpose. However, by integrating the disciplines of thermal and structural analysis, and fracture mechanics analysis a clearer understanding of the total aspect of the PTS problem has resulted. By adopting the CFD, thermal hydraulics, uncertainties and risk analysis for different type of accidental conditions, events and sequences with proper

  14. Hybrid heating systems optimization of residential environment to have thermal comfort conditions by numerical simulation.

    Science.gov (United States)

    Jahantigh, Nabi; Keshavarz, Ali; Mirzaei, Masoud

    2015-01-01

    The aim of this study is to determine optimum hybrid heating systems parameters, such as temperature, surface area of a radiant heater and vent area to have thermal comfort conditions. DOE, Factorial design method is used to determine the optimum values for input parameters. A 3D model of a virtual standing thermal manikin with real dimensions is considered in this study. Continuity, momentum, energy, species equations for turbulent flow and physiological equation for thermal comfort are numerically solved to study heat, moisture and flow field. K - ɛRNG Model is used for turbulence modeling and DO method is used for radiation effects. Numerical results have a good agreement with the experimental data reported in the literature. The effect of various combinations of inlet parameters on thermal comfort is considered. According to Pareto graph, some of these combinations that have significant effect on the thermal comfort require no more energy can be used as useful tools. A better symmetrical velocity distribution around the manikin is also presented in the hybrid system.

  15. Effects of thermal underwear on thermal and subjective responses in winter.

    Science.gov (United States)

    Choi, Jeong-Wha; Lee, Joo-Young; Kim, So-Young

    2003-01-01

    This study was conducted to obtain basic data in improving the health of Koreans, saving energy and protecting environments. This study investigated the effects of wearing thermal underwear for keeping warm in the office in winter where temperature is not as low as affecting work efficiency, on thermoregulatory responses and subjective sensations. In order to create an environment where every subject feels the same thermal sensation, two experimental conditions were selected through preliminary experiments: wearing thermal underwear in 18 degrees C air (18-condition) and not wearing thermal underwear in 23 degrees C air (23-condition). Six healthy male students participated in this study as experiment subjects. Measurement items included rectal temperature (T(re)), skin temperature (T(sk)), clothing microclimate temperature (T(cm)), thermal sensation and thermal comfort. The results are as follows: (1) T(re) of all subjects was maintained constant at 37.1 degrees C under both conditions, indicating no significant differences. (2) (T)(sk) under the 18-condition and the 23-condition were 32.9 degrees C and 33.7 degrees C, respectively, indicating a significant level of difference (pcomfortable under both conditions. It was found (T)(sk) decreased due to a drop in the skin temperature of hands and feet, and the subjects felt cooler wearing only one layer of normal thermal underwear at 18 degrees C. Yet, the thermal comfort level, T(re) and T(cm) of chest part under the 18-condition were the same as those under the 23-condition. These results show that the same level of comfort, T(re) and T(cm) can be maintained as that of an environment about 5 degrees C higher in the office in winter, by wearing one layer of thermal underwear. In this regard, this study suggests that lowering indoor temperature by wearing thermal underwear in winter can contribute to saving energy and improving health.

  16. Human biometeorological analysis of the thermal conditions of the hot Turkish city of Şanliurfa

    Science.gov (United States)

    Toy, Süleyman; Aytaç, Ahmet Serdar; Kántor, Noémi

    2018-01-01

    This paper offers a throughout human biometeorological assessment about the thermal conditions of Şanliurfa in one of the hottest parts of Turkey, in the hottest period of the year (from April to October), and a comparative analysis of three built-up types (urban, suburban and rural). Therefore, the values of physiologically equivalent temperature (PET), one of the most extensively used indices, were calculated from basic climate data with the help of the RayMan model. It was found by regarding the resulted mean PET values and the occurrence frequency of extreme heat stress periods (PET values above 41 °C) that the urban area exhibited the most unfavourable properties, followed by the suburban and rural areas. We also found very severe heat stress conditions in the summer, which may be explained by the torrid and arid climate, calm air conditions and the lack of abundant vegetation. Aiming to optimise human thermal conditions, thereby improving local life quality and facilitating international tourism, increment of vegetated areas and water surfaces would be required and, of course, highlighting the traditional methods taking into account the important aspects of sustainability.

  17. Thermal cycling fatigue of organic thermal interface materials using a thermal-displacement measurement technique

    Science.gov (United States)

    Steill, Jason Scott

    The long term reliability of polymer-based thermal interface materials (TIM) is essential for modern electronic packages which require robust thermal management. The challenge for today's materials scientists and engineers is to maximize the heat flow from integrated circuits through a TIM and out the heat sink. Thermal cycling of the electronic package and non-uniformity in the heat flux with respect to the plan area can lead to void formation and delamination which re-introduces inefficient heat transfer. Measurement and understanding at the nano-scale is essential for TIM development. Finding and documenting the evolution of the defects is dependent upon a full understanding of the thermal probes response to changing environmental conditions and the effects of probe usage. The response of the thermal-displacement measurement technique was dominated by changes to the environment. Accurate measurement of the thermal performance was hindered by the inability to create a model system and control the operating conditions. This research highlights the need for continued study into the probe's thermal and mechanical response using tightly controlled test conditions.

  18. Energetic performance analysis of a commercial water-based photovoltaic thermal system (PV/T) under summer conditions

    Science.gov (United States)

    Nardi, I.; Ambrosini, D.; de Rubeis, T.; Paoletti, D.; Muttillo, M.; Sfarra, S.

    2017-11-01

    In the last years, the importance of integrating the production of electricity with the production of sanitary hot water led to the development of new solutions, i.e. PV/T systems. It is well known that hybrid photovoltaic-thermal systems, able to produce electricity and thermal energy at the same time with better energetic performance in comparison with two separate systems, present many advantages for application in a residential building. A PV/T is constituted generally by a common PV panel with a metallic pipe, in which fluid flows. Pipe accomplishes two roles: it absorbs the heat from the PV panel, thus increasing, or at least maintaining its efficiency; furthermore, it stores the heat for sanitary uses. In this work, the thermal and electrical efficiencies of a commercial PV/T panel have been evaluated during the summer season in different days, to assess the effect of environmental conditions on the system total efficiency. Moreover, infrared thermographic diagnosis in real time has been effected during the operating mode in two conditions: with cooling and without cooling; cooling was obtained by natural flowing water. This analysis gave information about the impact of a non-uniform temperature distribution on the thermal and electrical performance. Furthermore, measurements have been performed in two different operating modes: 1) production of solely electrical energy and 2) simultaneous production of thermal and electrical energy. Finally, total efficiency is largely increased by using a simple solar concentrator nearby the panel.

  19. Importance of initial buoyancy field on evolution of mantle thermal structure: Implications of surface boundary conditions

    Directory of Open Access Journals (Sweden)

    Petar Glišović

    2015-01-01

    Full Text Available Although there has been significant progress in the seismic imaging of mantle heterogeneity, the outstanding issue that remains to be resolved is the unknown distribution of mantle temperature anomalies in the distant geological past that give rise to the present-day anomalies inferred by global tomography models. To address this question, we present 3-D convection models in compressible and self-gravitating mantle initialised by different hypothetical temperature patterns. A notable feature of our forward convection modelling is the use of self-consistent coupling of the motion of surface tectonic plates to the underlying mantle flow, without imposing prescribed surface velocities (i.e., plate-like boundary condition. As an approximation for the surface mechanical conditions before plate tectonics began to operate we employ the no-slip (rigid boundary condition. A rigid boundary condition demonstrates that the initial thermally-dominated structure is preserved, and its geographical location is fixed during the evolution of mantle flow. Considering the impact of different assumed surface boundary conditions (rigid and plate-like on the evolution of thermal heterogeneity in the mantle we suggest that the intrinsic buoyancy of seven superplumes is most-likely resolved in the tomographic images of present-day mantle thermal structure. Our convection simulations with a plate-like boundary condition reveal that the evolution of an initial cold anomaly beneath the Java-Indonesian trench system yields a long-term, stable pattern of thermal heterogeneity in the lowermost mantle that resembles the present-day Large Low Shear Velocity Provinces (LLSVPs, especially below the Pacific. The evolution of subduction zones may be, however, influenced by the mantle-wide flow driven by deeply-rooted and long-lived superplumes since Archean times. These convection models also detect the intrinsic buoyancy of the Perm Anomaly that has been identified as a unique

  20. The effect of atmospheric thermal conditions and urban thermal pollution on all-cause and cardiovascular mortality in Bangladesh.

    Science.gov (United States)

    Burkart, Katrin; Schneider, Alexandra; Breitner, Susanne; Khan, Mobarak Hossain; Krämer, Alexander; Endlicher, Wilfried

    2011-01-01

    This study assessed the effect of temperature and thermal atmospheric conditions on all-cause and cardiovascular mortality in Bangladesh. In particular, differences in the response to elevated temperatures between urban and rural areas were investigated. Generalized additive models (GAMs) for daily death counts, adjusted for trend, season, day of the month and age were separately fitted for urban and rural areas. Breakpoint models were applied for determining the increase in mortality above and below a threshold (equivalent) temperature. Generally, a 'V'-shaped (equivalent) temperature-mortality curve with increasing mortality at low and high temperatures was observed. Particularly, urban areas suffered from heat-related mortality with a steep increase above a specific threshold. This adverse heat effect may well increase with ongoing urbanization and the intensification of the urban heat island due to the densification of building structures. Moreover, rising temperatures due to climate change could aggravate thermal stress. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Stochastic simulation of PWR vessel integrity for pressurized thermal shock conditions

    International Nuclear Information System (INIS)

    Jackson, P.S.; Moelling, D.S.

    1984-01-01

    A stochastic simulation methodology is presented for performing probabilistic analyses of Pressurized Water Reactor vessel integrity. Application of the methodology to vessel-specific integrity analyses is described in the context of Pressurized Thermal Shock (PTS) conditions. A Bayesian method is described for developing vessel-specific models of the density of undetected volumetric flaws from ultrasonic inservice inspection results. Uncertainty limits on the probabilistic results due to sampling errors are determined from the results of the stochastic simulation. An example is provided to illustrate the methodology

  2. A Comparative Experimental Study of Fixed Temperature and Fixed Heat Flux Boundary Conditions in Turbulent Thermal Convection

    Science.gov (United States)

    Huang, Shi-Di; Wang, Fei; Xi, Heng-Dong; Xia, Ke-Qing

    2014-11-01

    We report an experimental study of the influences of thermal boundary condition in turbulent thermal convection. Two configurations were examined: one was fixed heat flux at the bottom boundary and fixed temperature at the top (HC cells); the other was fixed temperature at both boundaries (CC cells). It is found that the flow strength in the CC cells is on average 9% larger than that in the HC ones, which could be understood as change in plume emission ability under different boundary conditions. It is further found, rather surprisingly, that flow reversals of the large-scale circulation occur more frequently in the CC cell, despite a stronger large-scale flow and more uniform temperature distribution over the boundaries. These findings provide new insights into turbulent thermal convection and should stimulate further studies, especially experimental ones. This work is supported by the Hong Kong Research Grants Council under Grant No. CUHK 403712.

  3. Investigation of film boiling thermal hydraulics under FCI conditions. Results of a numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Dinh, T.N.; Dinh, A.T.; Nourgaliev, R.R.; Sehgal, B.R. [Div. of Nuclear Power Safety Royal Inst. of Tech. (RIT), Brinellvaegen 60, 10044 Stockholm (Sweden)

    1998-01-01

    Film boiling on the surface of a high-temperature melt jet or of a melt particle is one of key phenomena governing the physics of fuel-coolant interactions (FCIs) which may occur during the course of a severe accident in a light water reactor (LWR). A number of experimental and analytical studies have been performed, in the past, to address film boiling heat transfer and the accompanying hydrodynamic aspects. Most of the experiments have, however, been performed for temperature and heat flux conditions, which are significantly lower than the prototypic conditions. For ex-vessel FCIs, high liquid subcooling can significantly affect the FCI thermal hydraulics. Presently, there are large uncertainties in predicting natural-convection film boiling of subcooled liquids on high-temperature surfaces. In this paper, research conducted at the Division of Nuclear Power Safety, Royal Institute of Technology (RIT/NPS), Stockholm, concerning film-boiling thermal hydraulics under FCI condition is presented. Notably, the focus is placed on the effects of (1) water subcooling, (2) high-temperature steam properties, (3) the radiation heat transfer and (4) mixing zone boiling dynamics, on the vapor film characteristics. Numerical investigations are performed using a novel CFD modeling concept named as the local-homogeneous-slip model (LHSM). Results of the analytical and numerical studies are discussed with respect to boiling dynamics under FCI conditions. (author)

  4. Evaluation of Haney-Type Surface Thermal Boundary Conditions Using a Coupled Atmosphere and Ocean Model

    National Research Council Canada - National Science Library

    Chu, Peter C; Chen, Yuchun; Lu, Shihua

    2001-01-01

    ... (Russell et al,, 1995) was used to verify the validity of Haney-type surface thermal boundary condition, which linearly connects net downward surface heat flux Q to air / sea temperature difference DeltaT by a relaxation coefficient K...

  5. Normal conditions of transport thermal analysis and testing of a Type B drum package

    International Nuclear Information System (INIS)

    Jerrell, J.W.; Alstine, M.N. van; Gromada, R.J.

    1995-01-01

    Increasing the content limits of radioactive material packagings can save money and increase transportation safety by decreasing the total number of shipments required to transport large quantities of material. The contents of drum packages can be limited by unacceptable containment vessel pressures and temperatures due to the thermal properties of the insulation. The purpose of this work is to understand and predict the effects of insulation properties on containment system performance. The type B shipping container used in the study is a double containment fiberboard drum package. The package is primarily used to transport uranium and plutonium metals and oxides. A normal condition of transport (NCT) thermal test was performed to benchmark an NCT analysis of the package. A 21 W heater was placed in an instrumented package to simulate the maximum source decay heat. The package reached thermal equilibrium 120 hours after the heater was turned on. Testing took place indoors to minimize ambient temperature fluctuations. The thermal analysis of the package used fiberboard properties reported in the literature and resulted in temperature significantly greater than those measured during the test. Details of the NCT test will be described and transient temperatures at key thermocouple locations within the package will be presented. Analytical results using nominal fiberboard properties will be presented. Explanations of the results and the attempt to benchmark the analysis will be presented. The discovery that fiberboard has an anisotropic thermal conductivity and its effect on thermal performance will also be discussed

  6. Diurnal Thermal Behavior of Photovoltaic Panel with Phase Change Materials under Different Weather Conditions

    Directory of Open Access Journals (Sweden)

    Jae-Han Lim

    2017-12-01

    Full Text Available The electric power generation efficiency of photovoltaic (PV panels depends on the solar irradiation flux and the operating temperature of the solar cell. To increase the power generation efficiency of a PV system, this study evaluated the feasibility of phase change materials (PCMs to reduce the temperature rise of solar cells operating under the climate in Seoul, Korea. For this purpose, two PCMs with different phase change characteristics were prepared and the phase change temperatures and thermal conductivities were compared. The diurnal thermal behavior of PV panels with PCMs under the Seoul climate was evaluated using a 2-D transient thermal analysis program. This paper discusses the heat flow characteristics though the PV cell with PCMs and the effects of the PCM types and macro-packed PCM (MPPCM methods on the operating temperatures under different weather conditions. Selection of the PCM type was more important than the MMPCM methods when PCMs were used to enhance the performance of PV panels and the mean operating temperature of PV cell and total heat flux from the surface could be reduced by increasing the heat transfer rate through the honeycomb grid steel container for PCMs. Considering the mean operating temperature reduction of 4 °C by PCM in this study, an efficiency improvement of approximately 2% can be estimated under the weather conditions of Seoul.

  7. Space thermal control development

    Science.gov (United States)

    Hoover, M. J.; Grodzka, P. G.; Oneill, M. J.

    1971-01-01

    The results of experimental investigations on a number of various phase change materials (PCMs) and PCMs in combination with metals and other materials are reported. The evaluations include the following PCM system performance characteristics: PCM and PCM/filler thermal diffusivities, the effects of long-term thermal cycling, PCM-container compatibility, and catalyst effectiveness and stability. Three PCMs demonstrated performance acceptable enough to be considered for use in prototype aluminum thermal control devices. These three PCMs are lithium nitrate trihydrate with zinc hydroxy nitrate catalyst, acetamide, and myristic acid. Of the fillers tested, aluminum honeycomb filler was found to offer the most increase in system thermal diffusivity.

  8. Psychometric Properties of the Chinese Version of the Acceptance of Chronic Health Conditions (Stoma) Scale for Patients With Stoma.

    Science.gov (United States)

    Lim, Siew Hoon; He, Hong-Gu; Chan, Sally Wai Chi

    Formation of a stoma is a common outcome in surgical treatment of colorectal cancer. A higher acceptance of stoma was shown to improve quality of life of patients. No instrument in Chinese is available that can be used to measure the acceptance of stoma among patients with colorectal cancer. The aims of this study were to translate and test the psychometric properties of Chinese version of Acceptance of Chronic Health Conditions (ACHC) (Stoma) scale. A sample of 100 Chinese-speaking patients with stoma was recruited from a public tertiary care hospital in Singapore. The scale was translated into Chinese and reviewed by an expert panel for semantic equivalence and content validity testing. Convergent validity was established by exploring correlations between scores of the Chinese version of the ACHC (Stoma) scale and those of the 5-level version of European Quality of Life Questionnaire-5 Dimensions. Reliability was assessed by internal consistency and test-retest reliability. The newly translated scale had high content validity (content validity index = 94%) and acceptable internal consistency (Cronbach's α = .846). The test-retest reliability was satisfactory with an intraclass coefficient of 0.997. A positive correlation was found between both scores on ACHC (Stoma) scale and EQ-5D utility score (r = 0.63, P Stoma) scale demonstrated satisfactory content validity, good convergent validity, and adequate internal consistency and stability. This scale can be used as a convenient screening tool in clinical settings to assess the level of acceptance in Chinese-speaking patients with stoma.

  9. Infrared survey of 50 buildings constructed during 100 years: thermal performances and damage conditions

    Science.gov (United States)

    Ljungberg, Sven-Ake

    1995-03-01

    Different building constructions and craftsmanship give rise to different thermal performance and damage conditions. The building stock of most industrial countries consists of buildings of various age, and constructions, from old historic buildings with heavy stone or wooden construction, to new buildings with heavy or light concrete construction, or modern steel or wooden construction. In this paper the result from a detailed infrared survey of 50 buildings from six Swedish military camps is presented. The presentation is limited to a comparison of thermal performance and damage conditions of buildings of various ages, functions, and constructions, of a building period of more than 100 years. The result is expected to be relevant even to civilian buildings. Infrared surveys were performed during 1992-1993, with airborne, and mobile short- and longwave infrared systems, out- and indoor thermography. Interpretation and analysis of infrared data was performed with interactive image and analyzing systems. Field inspections were carried out with fiber optics system, and by ocular inspections. Air-exchange rate was measured in order to quantify air leakages through the building envelope, indicated in thermograms. The objects studied were single-family houses, barracks, office-, service-, school- and exercise buildings, military hotels and restaurants, aircraft hangars, and ship factory buildings. The main conclusions from this study are that most buildings from 1880 - 1940 have a solid construction with a high quality of craftsmanship, relatively good thermal performance, due to extremely thick walls, and adding insulation at the attic floor. From about 1940 - 1960 the quality of construction, thermal performance and craftsmanship seem to vary a lot. Buildings constructed during the period of 1960 - 1990 have in general the best thermal performance due to a better insulation capacity, however, also one finds here the greatest variety of problems. The result from this

  10. Gerontechnology acceptance by elderly Hong Kong Chinese: a senior technology acceptance model (STAM).

    Science.gov (United States)

    Chen, Ke; Chan, Alan Hoi Shou

    2014-01-01

    The purpose of this study was to develop and test a senior technology acceptance model (STAM) aimed at understanding the acceptance of gerontechnology by older Hong Kong Chinese people. The proposed STAM extended previous technology acceptance models and theories by adding age-related health and ability characteristics of older people. The proposed STAM was empirically tested using a cross-sectional questionnaire survey with a sample of 1012 seniors aged 55 and over in Hong Kong. The result showed that STAM was strongly supported and could explain 68% of the variance in the use of gerontechnology. For older Hong Kong Chinese, individual attributes, which include age, gender, education, gerontechnology self-efficacy and anxiety, and health and ability characteristics, as well as facilitating conditions explicitly and directly affected technology acceptance. These were better predictors of gerontechnology usage behaviour (UB) than the conventionally used attitudinal factors (usefulness and ease of use).

  11. Thermal Conditions in the City of Poznań (Poland during Selected Heat Waves

    Directory of Open Access Journals (Sweden)

    Marek Półrolniczak

    2018-01-01

    Full Text Available The aim of the study was to characterise the occurrence of hot days and heat waves in Poznań in the 1966–2015 period, as well as to describe the thermal conditions in the city during selected heat waves between 2008 and 2015. The basis of the study was the daily maximum and minimum air temperature values for Poznań–Ławica station from 1966–2015 and the daily values of air temperature from eight measuring points located in the city in various land types from 2008 to 2015. A hot day was defined as a day with Tmax above the 95th annual percentile (from 1966 to 2015, while a heat wave was assumed to be at least five consecutive hot days. The research study conducted shows the increase of Tmax, number of hot days and frequency of heat waves in Poznań over the last 50 years. Across the area of the city (differentiation of urban area types according to Urban Atlas 2012, there was a great diversity of thermal conditions during the heat waves analysed.

  12. A dynamic switching strategy for air-conditioning systems operated in light-thermal-load conditions

    International Nuclear Information System (INIS)

    Lin, Jin-Long; Yeh, T.-J.; Hwang, Wei-Yang

    2009-01-01

    Recently, modern air-conditioners have begun to incorporate variable-speed compressors and variable-opening expansion valves, together with feedback control to improve the performance and energy efficiency. However, for the compressor there usually exists a low-speed limit below which its speed can not be continuously modulated unless it is completely turned off. When the air-conditioning system is operated in light-thermal-load conditions, the low-speed limit causes the compressor to run in an on-off manner which can significantly degrade the performance and efficiency. In this paper, a dynamic switching strategy is proposed for such scenarios. The strategy is basically an integration of a cascading control structure, an intuitive switching strategy, and a dynamic compensator. While the control structure provides the nominal performance, the intuitive switching strategy and the dynamic compensator together can account for the compressor's low-speed limitation. Theoretical analysis reveals that when the output matrix of the dynamic compensator is chosen properly, the proposed strategy can effectively reduce the output error caused by the on-off operation of the compressor. Experiments also demonstrate that the proposed strategy can simultaneously provide better regulation for the indoor temperature and improve the energy efficiency at steady state.

  13. The Borexino Thermal Monitoring & Management System and simulations of the fluid-dynamics of the Borexino detector under asymmetrical, changing boundary conditions

    Science.gov (United States)

    Bravo-Berguño, D.; Mereu, R.; Cavalcante, P.; Carlini, M.; Ianni, A.; Goretti, A.; Gabriele, F.; Wright, T.; Yokley, Z.; Vogelaar, R. B.; Calaprice, F.; Inzoli, F.

    2018-03-01

    A comprehensive monitoring system for the thermal environment inside the Borexino neutrino detector was developed and installed in order to reduce uncertainties in determining temperatures throughout the detector. A complementary thermal management system limits undesirable thermal couplings between the environment and Borexino's active sections. This strategy is bringing improved radioactive background conditions to the region of interest for the physics signal thanks to reduced fluid mixing induced in the liquid scintillator. Although fluid-dynamical equilibrium has not yet been fully reached, and thermal fine-tuning is possible, the system has proven extremely effective at stabilizing the detector's thermal conditions while offering precise insights into its mechanisms of internal thermal transport. Furthermore, a Computational Fluid-Dynamics analysis has been performed, based on the empirical measurements provided by the thermal monitoring system, and providing information into present and future thermal trends. A two-dimensional modeling approach was implemented in order to achieve a proper understanding of the thermal and fluid-dynamics in Borexino. It was optimized for different regions and periods of interest, focusing on the most critical effects that were identified as influencing background concentrations. Literature experimental case studies were reproduced to benchmark the method and settings, and a Borexino-specific benchmark was implemented in order to validate the modeling approach for thermal transport. Finally, fully-convective models were applied to understand general and specific fluid motions impacting the detector's Active Volume.

  14. Thermal fatigue testing of a diffusion-bonded beryllium divertor mock-up under ITER relevant conditions

    International Nuclear Information System (INIS)

    Youchison, D.L.; Guiniiatouline, R.; Watson, R.D.

    1994-01-01

    Thermal response and thermal fatigue tests of four 5 mm thick beryllium tiles on a Russian divertor mock-up were completed on the Electron Beam Test System at Sandia National Laboratories. The beryllium tiles were diffusion bonded onto an OFHC copper saddleblock and a DSCu (MAGT) tube containing a porous coating. Thermal response tests were performed on the tiles to an absorbed heat flux of 5 MW/m 2 and surface temperatures near 300 degrees C using 1.4 MPa water at 5.0 m/s flow velocity and an inlet temperature of 8-15 degrees C. One tile was exposed to incrementally increasing heat fluxes up to 9.5 MW/m 2 and surface temperatures up to 690 degrees C before debonding at 10 MW/m 2 . A third tile debonded after 9200 thermal fatigue cycles at 5 MW/m 2 , while another debonded after 6800 cycles. In all cases, fatigue failure occurred in the intermetallic layers between the beryllium and copper. No fatigue cracking of the bulk beryllium was observed. During thermal cycling, a gradual loss of porous coating produced increasing sample temperatures. These experiments indicate that diffusion-bonded beryllium tiles can survive several thousand thermal cycles under ITER relevant conditions without failure. However, the reliability of the diffusion bonded Joint remains a serious issue

  15. Thermal comfort of various building layouts with a proposed discomfort index range for tropical climate.

    Science.gov (United States)

    Md Din, Mohd Fadhil; Lee, Yee Yong; Ponraj, Mohanadoss; Ossen, Dilshan Remaz; Iwao, Kenzo; Chelliapan, Shreeshivadasan

    2014-04-01

    Recent years have seen issues related to thermal comfort gaining more momentum in tropical countries. The thermal adaptation and thermal comfort index play a significant role in evaluating the outdoor thermal comfort. In this study, the aim is to capture the thermal sensation of respondents at outdoor environment through questionnaire survey and to determine the discomfort index (DI) to measure the thermal discomfort level. The results indicated that most respondents had thermally accepted the existing environment conditions although they felt slightly warm and hot. A strong correlation between thermal sensation and measured DI was also identified. As a result, a new discomfort index range had been proposed in association with local climate and thermal sensation of occupants to evaluate thermal comfort. The results had proved that the respondents can adapt to a wider range of thermal conditions.Validation of the questionnaire data at Putrajaya was done to prove that the thermal sensation in both Putrajaya and UTM was almost similar since they are located in the same tropical climate region. Hence, a quantitative field study on building layouts was done to facilitate the outdoor human discomfort level based on newly proposed discomfort index range. The results showed that slightly shaded building layouts of type- A and B exhibited higher temperature and discomfort index. The resultant adaptive thermal comfort theory was incorporated into the field studies as well. Finally, the study also showed that the DI values were highly dependent on ambient temperature and relative humidity but had fewer effects for solar radiation intensity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Studies in the statistical and thermal properties of hadronic matter under some extreme conditions

    International Nuclear Information System (INIS)

    Chase, K.C.; Mekjian, A.Z.; Bhattacharyya, P.

    1997-01-01

    The thermal and statistical properties of hadronic matter under some extreme conditions are investigated using an exactly solvable canonical ensemble model. A unified model describing both the fragmentation of nuclei and the thermal properties of hadronic matter is developed. Simple expressions are obtained for quantities such as the hadronic equation of state, specific heat, compressibility, entropy, and excitation energy as a function of temperature and density. These expressions encompass the fermionic aspect of nucleons, such as degeneracy pressure and Fermi energy at low temperatures and the ideal gas laws at high temperatures and low density. Expressions are developed which connect these two extremes with behavior that resembles an ideal Bose gas with its associated Bose condensation. In the thermodynamic limit, an infinite cluster exists below a certain critical condition in a manner similar to the sudden appearance of the infinite cluster in percolation theory. The importance of multiplicity fluctuations is discussed and some recent data from the EOS collaboration on critical point behavior of nuclei can be accounted for using simple expressions obtained from the model. copyright 1997 The American Physical Society

  17. Hypothetical accident conditions free drop and thermal tests USA/5791/BLF (ERDA-AL)

    International Nuclear Information System (INIS)

    Blankenship, R.W.

    1980-05-01

    The USA/5791/BLF (ERDA-AL) shipping container with rolled-top food pack cans as inner containers is evaluated under conditions required by 10 CFR 71.42. One kilogram of depleted uranium as UO 2 was packaged in each of the inner containers. After completion of a free drop test and a simulated thermal test, the maximum observed leakage of UO 2 for the following week was 3.0 μg. This leakage is well below the allowable leakage per week for most plutonium isotopic mixtures. Using the examples provided, any plutonium isotopic mixture can be easily compared with the allowable leakage per week. Test conditions and results are reported

  18. The Effect of Fuel Mass Fraction on the Combustion and Fluid Flow in a Sulfur Recovery Unit Thermal Reactor

    Directory of Open Access Journals (Sweden)

    Chun-Lang Yeh

    2016-11-01

    Full Text Available Sulfur recovery unit (SRU thermal reactors are negatively affected by high temperature operation. In this paper, the effect of the fuel mass fraction on the combustion and fluid flow in a SRU thermal reactor is investigated numerically. Practical operating conditions for a petrochemical corporation in Taiwan are used as the design conditions for the discussion. The simulation results show that the present design condition is a fuel-rich (or air-lean condition and gives acceptable sulfur recovery, hydrogen sulfide (H2S destruction, sulfur dioxide (SO2 emissions and thermal reactor temperature for an oxygen-normal operation. However, for an oxygen-rich operation, the local maximum temperature exceeds the suggested maximum service temperature, although the average temperature is acceptable. The high temperature region must be inspected very carefully during the annual maintenance period if there are oxygen-rich operations. If the fuel mass fraction to the zone ahead of the choke ring (zone 1 is 0.0625 or 0.125, the average temperature in the zone behind the choke ring (zone 2 is higher than the zone 1 average temperature, which can damage the downstream heat exchanger tubes. If the zone 1 fuel mass fraction is reduced to ensure a lower zone 1 temperature, the temperature in zone 2 and the heat exchanger section must be monitored closely and the zone 2 wall and heat exchanger tubes must be inspected very carefully during the annual maintenance period. To determine a suitable fuel mass fraction for operation, a detailed numerical simulation should be performed first to find the stoichiometric fuel mass fraction which produces the most complete combustion and the highest temperature. This stoichiometric fuel mass fraction should be avoided because the high temperature could damage the zone 1 corner or the choke ring. A higher fuel mass fraction (i.e., fuel-rich or air-lean condition is more suitable because it can avoid deteriorations of both zone 1

  19. Thermal behaviour of high burnup PWR fuel under different fill gas conditions

    International Nuclear Information System (INIS)

    Tverberg, T.

    2001-01-01

    During its more than 40 years of existence, a large number of experiments have been carried out at the Halden Reactor Project focusing on different aspects related to nuclear reactor fuel. During recent years, the fuels testing program has mainly been focusing on aspects related to high burnup, in particular in terms of fuel thermal performance and fission gas release, and often involving reinstrumentation of commercially irradiated fuel. The paper describes such an experiment where a PWR rod, previously irradiated in a commercial reactor to a burnup of ∼50 MWd/kgUO 2 , was reinstrumented with a fuel central oxide thermocouple and a cladding extensometer together with a high pressure gas flow line, allowing for different fill gas compositions and pressures to be applied. The paper focuses on the thermal behaviour of such LWR rods with emphasis on how different fill gas conditions influence the fuel temperatures and gap conductance. Rod growth rate was also monitored during the irradiation in the Halden reactor. (author)

  20. Effect of thermal treatment conditions on properties of vanadium molybdenum oxide catalyst in acrolein oxidation reaction to acrylic acid

    International Nuclear Information System (INIS)

    Gorshkova, T.P.; Tarasova, D.V.; Olen'kova, I.P.; Andrushkevich, T.V.; Nikoro, T.A.

    1984-01-01

    The effect of thermal treatment conditions (temperature and gas medium) on properties of vanadium molybdenum oxide catalyst in acrolein oxidation reaction to acrylic acid is investigated. It is shown that active and selective catalysts are formed in the course of thermal decomposition of the drying product of ammonium metavanadate and paramolybdate under the conditions ensuring the vanadium ion reduction up to tetravalent state with conservation of molybdenum oxidation degree equal to 6. It is possible to realize it either by treatment of the catalyst calcinated in the air flow at 300 deg by the reaction mixture at the activation stage or by gas-reducer flow treatment at 280 deg. Thermal treatment in the reducing medium of the oxidized catalyst does not lead to complete regeneration of its properties

  1. Metallurgical properties of reduced activation martensitic steel Eurofer'97 in the as-received condition and after thermal ageing

    International Nuclear Information System (INIS)

    Fernandez, P.; Lancha, A.M.; Lapena, J.; Serrano, M.; Hernandez-Mayoral, M.

    2002-01-01

    This paper describes the microstructural studies and the mechanical testing (hardness, tensile and charpy tests) performed on the Eurofer'97 steel in the as-received condition and after thermal ageing treatments up to 600 deg. C. In addition, fracture toughness tests on the as-received condition have been carried out in order to determine the Master Curve. During the thermal ageing treatments studied (500 deg. C/5000 h and 600 deg. C/1000 h) the general microstructure of the steel (tempered martensite with M 23 C 6 and MX precipitates) remained stable. Only a slight growth of the particles has been observed. In terms of mechanical properties, the Eurofer'97 steel exhibited similar values of tensile properties (tensile and yield strength) and ductile-brittle transition temperature regardless of the material condition studied.

  2. Acceptance and Utilization of Technology (UTAUT) as a Method of Technology Acceptance Model of Mitigation Disaster Website

    Science.gov (United States)

    Siswanto, T.; Shofiati, R.; Hartini, H.

    2018-01-01

    www.mitigasi-bencana.com as a knowledge management website created based on survey results in April-July 2014 in East Java and Central Java provinces, indicates a gap between the expectations and reality that exist in the services provided by the regional disaster management agency. Based on condition analysis, the gaps that occur can be reduced if the community has the understanding and knowledge of adequate disaster mitigation. The problem that arises later is whether the chosen technology solution is appropriate and acceptable to the public? The methodology used in this study using the Technology Acceptance Model development is the Unified Theory of Acceptance and Utilization of Technology (UTAUT). Feedback obtained from respondents KarangTaruna youth SelogedongBantul, www.mitigasi-bencana.com can be accepted by the respondents, but from processed data is obtained only UTAUT hypotheses on the relationship dimension eligible for Social Expectancy on the Attitude toward technology, which means the higher the perception of the Social Expectancy, the higher the perception of the Attitude toward technology. Because www.mitigasi-bencana.com is new socialized so that society still need time to explore content information and knowledge contained therein. To be accepted by user, a knowledge management application must prepare various aspects of Performance Expectancy, Effort Expectancy, Social Factors, Facilitating Conditions and Attitude.

  3. Cooling Performance Characteristics of the Stack Thermal Management System for Fuel Cell Electric Vehicles under Actual Driving Conditions

    Directory of Open Access Journals (Sweden)

    Ho-Seong Lee

    2016-04-01

    Full Text Available The cooling performance of the stack radiator of a fuel cell electric vehicle was evaluated under various actual road driving conditions, such as highway and uphill travel. The thermal stability was then optimized, thereby ensuring stable operation of the stack thermal management system. The coolant inlet temperature of the radiator in the highway mode was lower than that associated with the uphill mode because the corresponding frontal air velocity was higher than obtained in the uphill mode. In both the highway and uphill modes, the coolant temperatures of the radiator, operated under actual road driving conditions, were lower than the allowable limit (80 °C; this is the maximum temperature at which stable operation of the stack thermal management system of the fuel cell electric vehicle could be maintained. Furthermore, under actual road driving conditions in uphill mode, the initial temperature difference (ITD between the coolant temperature and air temperature of the system was higher than that associated with the highway mode; this higher ITD occurred even though the thermal load of the system in uphill mode was greater than that corresponding to the highway mode. Since the coolant inlet temperature is expected to exceed the allowable limit (80 °C in uphill mode under higher ambient temperature with air conditioning system operation, the FEM design layout should be modified to improve the heat capacity. In addition, the overall volume of the stack cooling radiator is 52.2% higher than that of the present model and the coolant inlet temperature of the improved radiator is 22.7% lower than that of the present model.

  4. Investigation of Thermal Comfort Conditions in Higher Education Facilities: A Case Study for Engineering Faculty in Edirne

    Directory of Open Access Journals (Sweden)

    E. Mıhlayanlar

    2017-02-01

    Full Text Available In this study, a higher education institution in Edirne (Trakya University Engineering Faculty is investigated for indoor thermal comfort conditions of the classrooms (indoor temperature, relative humidity, average radiant temperature, “Satisfaction from thermal environment” (PMV and “Dissatisfaction from thermal environment” (PPD. The classrooms in the institution are heated by a central heating system and utilise natural ventilation system. Measurements were taken with the proper devices at the same time of the weekdays during lecture times in winter (heating season in December. The results obtained from measurements are given in graphics and compared with the values given in ASHRAE 55 and ISO 7730 standards.

  5. Summary of research and development activities in support of waste acceptance criteria for WIPP

    International Nuclear Information System (INIS)

    Hunter, T.O.

    1979-11-01

    The development of waste acceptance criteria for the Waste Isolation Pilot Plant (WIPP) is summarized. Specifications for acceptable waste forms are included. Nine program areas are discussed. They are: TRU characterization, HLW interactions, thermal/structural interactions, nuclide migration, permeability, brine migration, borehole plugging, operation/design support, and instrumentation development. Recommendations are included

  6. Thermal analysis on NAC-STC spent fuel transport cask under different transport conditions

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yumei [Institute of Process Equipment, Zhejiang University, Hangzhou (China); Yang, Jian, E-mail: zdhjkz@zju.edu.cn [Institute of Process Equipment, Zhejiang University, Hangzhou (China); Xu, Chao; Wang, Weiping [Institute of Process Equipment, Zhejiang University, Hangzhou (China); Ma, Zhijun [Department of Material Engineering, South China University of Technology, Guangzhou (China)

    2013-12-15

    Highlights: • Spent fuel cask was investigated as a whole instead of fuel assembly alone. • The cask was successfully modeled and meshed after several simplifications. • Equivalence method was used to calculate the properties of parts. • Both the integral thermal field and peak values are captured to verify safety. • The temperature variations of key parts were also plotted. - Abstract: Transport casks used for conveying spent nuclear fuel are inseparably related to the safety of the whole reprocessing system for spent nuclear fuel. Thus they must be designed according to rigorous safety standards including thermal analysis. In this paper, for NAC-STC cask, a finite element model is established based on some proper simplifications on configurations and the heat transfer mechanisms. Considering the complex components and gaps, the equivalence method is presented to define their material properties. Then an equivalent convection coefficient is introduced to define boundary conditions. Finally, the temperature field is captured and analyzed under both normal and accident transport conditions by using ANSYS software. The validity of numerical calculation is given by comparing its results with theoretical calculation. Obtaining the integral distribution laws of temperature and peak temperature values of all vital components, the security of the cask can be evaluated and verified.

  7. Deconvolution of Thermal Emissivity Spectra of Mercury to their Endmember Counterparts measured in Simulated Mercury Surface Conditions

    Science.gov (United States)

    Varatharajan, I.; D'Amore, M.; Maturilli, A.; Helbert, J.; Hiesinger, H.

    2017-12-01

    The Mercury Radiometer and Thermal Imaging Spectrometer (MERTIS) payload of ESA/JAXA Bepicolombo mission to Mercury will map the thermal emissivity at wavelength range of 7-14 μm and spatial resolution of 500 m/pixel [1]. Mercury was also imaged at the same wavelength range using the Boston University's Mid-Infrared Spectrometer and Imager (MIRSI) mounted on the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii with the minimum spatial coverage of 400-600km/spectra which blends all rocks, minerals, and soil types [2]. Therefore, the study [2] used quantitative deconvolution algorithm developed by [3] for spectral unmixing of this composite thermal emissivity spectrum from telescope to their respective areal fractions of endmember spectra; however, the thermal emissivity of endmembers used in [2] is the inverted reflectance measurements (Kirchhoff's law) of various samples measured at room temperature and pressure. Over a decade, the Planetary Spectroscopy Laboratory (PSL) at the Institute of Planetary Research (PF) at the German Aerospace Center (DLR) facilitates the thermal emissivity measurements under controlled and simulated surface conditions of Mercury by taking emissivity measurements at varying temperatures from 100-500°C under vacuum conditions supporting MERTIS payload. The measured thermal emissivity endmember spectral library therefore includes major silicates such as bytownite, anorthoclase, synthetic glass, olivine, enstatite, nepheline basanite, rocks like komatiite, tektite, Johnson Space Center lunar simulant (1A), and synthetic powdered sulfides which includes MgS, FeS, CaS, CrS, TiS, NaS, and MnS. Using such specialized endmember spectral library created under Mercury's conditions significantly increases the accuracy of the deconvolution model results. In this study, we revisited the available telescope spectra and redeveloped the algorithm by [3] by only choosing the endmember spectral library created at PSL for unbiased model

  8. Optimum thermal sizing and operating conditions for once through steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Kunwoo; Ju, Kyongin; Im, Inyoung; Kim, Eunkee [KEPCO Engineering and Construction Company., Inc., Daejeon (Korea, Republic of)

    2014-10-15

    The steam generator is designed to be optimized so as to remove heat and to produce steam vapor. Because of its importance, theoretical and experimental researches have been performed on forced convection boiling heat transfer. The purpose of this study is to predict the thermal behavior and to perform optimum thermal sizing of once through steam generator. To estimate the tube thermal sizing and operating conditions of the steam generator, the analytical modeling is employed on the basis of the empirical correlation equations and theory. The optimized algorithm model, Non-dominated Sorting Genetic Algorithm (NSGA)-II, uses for this analysis. This research is focused on the design of in-vessel steam generator. An one dimensional analysis code is developed to evaluate previous researches and to optimize steam generator design parameters. The results of one-dimensional analysis need to be verified with experimental data. Goals of multi-objective optimization are to minimize tube length, pressure drop and tube number. Feedwater flow rate up to 115.425kg/s is selected so as to have margin of feedwater temperature 20 ..deg. C. For the design of 200MWth once through steam generator, it is evaluated that the tube length shall be over 12.0m for the number of tubes, 2500ea, and the length of the tube shall be over 8.0m for the number of tubes, 4500ea. The parallel coordinates chart can be provided to determine the optimal combination of number of tube, pressure drop, tube diameter and length.

  9. Brief Mindfulness Meditation Training Reduces Mind-Wandering: The Critical Role of Acceptance

    Science.gov (United States)

    Rahl, Hayley A.; Lindsay, Emily K.; Pacilio, Laura E.; Brown, Kirk W.; Creswell, J. David

    2016-01-01

    Mindfulness meditation programs, which train individuals to monitor their present moment experience in an open or accepting way, have been shown to reduce mind-wandering on standardized tasks in several studies. Here we test two competing accounts for how mindfulness training reduces mind-wandering, evaluating whether the attention monitoring component of mindfulness training alone reduces mind-wandering or whether the acceptance training component is necessary for reducing mind-wandering. Healthy young adults (N=147) were randomized to either a 3-day brief mindfulness training condition incorporating instruction in both attention monitoring and acceptance, a mindfulness training condition incorporating attention monitoring instruction only, a relaxation training condition, or a reading control condition. Participants completed measures of dispositional mindfulness and treatment expectancies before the training session on Day 1 and then completed a 6-minute Sustained Attention Response Task (SART) measuring mind-wandering after the training session on Day 3. Acceptance training was important for reducing mind-wandering, such that the monitoring + acceptance mindfulness training condition had the lowest mind-wandering relative to the other conditions, including significantly lower mind-wandering relative to the monitor-only mindfulness training condition. In one of the first experimental mindfulness training dismantling studies to-date, we show that training in acceptance is a critical driver of mindfulness training reductions in mind-wandering. This effect suggests that acceptance skills may facilitate emotion regulation on boring and frustrating sustained attention tasks that foster mind-wandering, such as the SART. PMID:27819445

  10. Preliminary waste acceptance requirements - Konrad repository project

    International Nuclear Information System (INIS)

    Brennecke, P.W.; Warnecke, E.H.

    1991-01-01

    In Germany, the planned Konrad repository is proposed for the disposal of all types of radioactive wastes whose thermal influence upon the host rock is negligible. The Bundesamt fuer Strahlenschutz has established Preliminary Waste Acceptance Requirements (as of April 1990) for this facility. The respective requirements were developed on the basis of the results of site-specific safety assessments. They include general requirements on the waste packages to be disposed of as well as more specific requirements on the waste forms, the packaging and the radionuclide inventory per waste package. In addition, the delivery of waste packages was regulated. An outline of the structure and the elements of the Preliminary Waste Acceptance Requirements of April 1990 is given including comments on their legal status. (Author)

  11. Thermal Impact Assessment of Groundwater Heat Pumps (GWHPs: Rigorous vs. Simplified Models

    Directory of Open Access Journals (Sweden)

    Bruno Piga

    2017-09-01

    Full Text Available Groundwater Heat Pumps (GWHPs are increasingly adopted for air conditioning in urban areas, thus reducing CO2 emissions, and this growth needs to be managed to ensure the sustainability of the thermal alteration of aquifers. However, few studies have addressed the propagation of thermal plumes from open-loop geothermal systems from a long-term perspective. We provide a comprehensive sensitivity analysis, performed with numerical finite-element simulations, to assess how the size of the thermally affected zone is driven by hydrodynamic and thermal subsurface properties, the vadose zone and aquifer thickness, and plant setup. In particular, we focus the analysis on the length and width of thermal plumes, and on their time evolution. Numerical simulations are compared with two simplified methods, namely (i replacing the time-varying thermal load with its yearly average and (ii analytical formulae for advective heat transport in the aquifer. The former proves acceptable for the assessment of plume length, while the latter can be used to estimate the width of the thermally affected zone. The results highlight the strong influence of groundwater velocity on the plume size and, especially for its long-term evolution, of ground thermal properties and of subsurface geometrical parameters.

  12. Creep and Environmental Durability of EBC/CMCs Under Imposed Thermal Gradient Conditions

    Science.gov (United States)

    Appleby, Matthew; Morscher, Gregory N.; Zhu, Dongming

    2013-01-01

    Interest in SiC fiber-reinforced SiC ceramic matrix composite (CMC) environmental barrier coating (EBC) systems for use in high temperature structural applications has prompted the need for characterization of material strength and creep performance under complex aerospace turbine engine environments. Stress-rupture tests have been performed on SiC/SiC composites systems, with varying fiber types and coating schemes to demonstrate material behavior under isothermal conditions. Further testing was conducted under exposure to thermal stress gradients to determine the effect on creep resistance and material durability. In order to understand the associated damage mechanisms, emphasis is placed on experimental techniques as well as implementation of non-destructive evaluation; including electrical resistivity monitoring. The influence of environmental and loading conditions on life-limiting material properties is shown.

  13. Gas Control and Thermal Modeling Methods for Pressed Pellet and Fast Rise Thin-Film Thermal Batteries

    Science.gov (United States)

    2015-09-01

    high operating battery case temperatures. Acceptable hermetic seals for thermal batteries ordinarily use laser welding , tungsten inert gas ( TIG ...20 Fig. 16 Sierra TABS Internal Plotter – Final pre- processing step for Low Cost Competent Munition (LCCM) thermal battery (battery shown drawn to...of experimental and DOE statistical methods. Such studies could be used to identify 2 electrochemical and thermodynamic processes that occur

  14. Cellulose nanowhiskers from coconut husk fibers: effect of preparation conditions on their thermal and morphological behavior

    Science.gov (United States)

    Cellulose nanowhiskers were prepared by sulfuric acid hydrolysis from coconut husk fibers which had previously been submitted to a delignification process. The effects of preparation conditions on the thermal and morphological behavior of the nanocrystals were investigated. Cellulose nanowhisker sus...

  15. Thermal Interaction of Closely Spaced Persons

    DEFF Research Database (Denmark)

    Brohus, Henrik; Nielsen, Peter V.; Tøgersen, Michael

    2011-01-01

    This paper presents results from a pilot study on the thermal interaction of closely spaced persons in a large enclosure. The surface temperature at different densities of persons is evaluated using a high resolution thermo vision camera in a controlled thermal environment. The corresponding ther...... thermal sensation is evaluated using questionnaires for the various densities. The results indicate that it may be acceptable to consider persons standalone, in a thermal sense, disregarding thermal interaction at usual densities in the design of large enclosures.......This paper presents results from a pilot study on the thermal interaction of closely spaced persons in a large enclosure. The surface temperature at different densities of persons is evaluated using a high resolution thermo vision camera in a controlled thermal environment. The corresponding...

  16. N,N-Diethyl-1-Tosyl-3-Indoleglyoxylamide as a Dienophile in Diels-Alder Reactions. Hyperbaric vs. Thermal Conditions

    Directory of Open Access Journals (Sweden)

    B. Biolatto

    2000-03-01

    Full Text Available Under high pressure conditions, the Diels-Alder reaction involving N,N-diethyl-1-tosyl-3-indoleglyoxylamide and 1-(N-acetyl-N-propylamino-1,3-butadiene produces a highly functionalized intermediate for the synthesis of Indole Alkaloids, in shorter times and higher yields than under thermal conditions.

  17. Predicting Public Acceptability in Controversial Technologies

    International Nuclear Information System (INIS)

    Bruce, Donald M.

    2003-01-01

    Technology and society have a synergic relationship. New technologies are a product of the values and aspirations of the culture in which they emerge. In turn, each new technology shapes and alters these values and aspirations, to a greater or lesser degree. The acceptance by society of any particular technology depends, however, on how far the values embodied in the technology reflect those of the wider society, or only those of some privileged sector - perhaps a ruling elite, a group of academic researchers, a commercial company, or even a special interest group. As public disquiet about controversial technologies has grown, their acceptance can no longer be taken for granted. It is now becoming more important to evaluate in advance the degree of likely mismatch between the aspirations of the technologists and the values of society. This paper explores one approach to making this evaluation, based on the notion of a conditional social contract between technology and society. A given society may be prepared to embrace a new technology to deliver certain benefits, and may accept a certain degree of risk and adaptation of life styles, provided certain basic conditions are fulfilled. These conditions include the upholding of basic values, familiarity, how it compares with similar technologies, the degree of control and choice, trust in those in control, the nature of any risks, the tangible benefits, and the media profile given to the new area. If several of these factors are not fulfilled, the technology is unlikely to be accepted. This was dramatically illustrated in the UK public reaction to food products derived from imported US GM soya and maize. These failed nearly all the conditions, so that public rejection should have been seen as a foregone conclusion. In the light of this, the likely public reaction to a number of future biotechnological innovations is assessed, based on the same conditions. Some examples taken from the energy sector are also compared. The

  18. Heating, ventilating, and air conditioning deactivation thermal analysis of PUREX Plant

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.W.; Gregonis, R.A. [Westinghouse Hanford Company, Richland, WA (United States)

    1997-08-01

    Thermal analysis was performed for the proposed Plutonium Uranium Extraction Plant exhaust system after deactivation. The purpose of the analysis was to determine if enough condensation will occur to plug or damage the filtration components. A heat transfer and fluid flow analysis was performed to evaluate the thermal characteristics of the underground duct system, the deep-bed glass fiber filter No. 2, and the high-efficiency particulate air filters in the fourth filter building. The analysis is based on extreme variations of air temperature, relative humidity, and dew point temperature using 15 years of Hanford Site weather data as a basis. The results will be used to evaluate the need for the electric heaters proposed for the canyon exhaust to prevent condensation. Results of the analysis indicate that a condition may exist in the underground ductwork where the duct temperature can lead or lag changes in the ambient air temperature. This condition may contribute to condensation on the inside surfaces of the underground exhaust duct. A worst case conservative analysis was performed assuming that all of the water is removed from the moist air over the inside surface of the concrete duct area in the fully developed turbulent boundary layer while the moist air in the free stream will not condense. The total moisture accumulated in 24 hours is negligible. Water puddling would not be expected. The results of the analyses agree with plant operating experiences. The filters were designed to resist high humidity and direct wetting, filter plugging caused by slight condensation in the upstream duct is not a concern. 19 refs., 2 figs.

  19. Short-term airing by natural ventilation - implication on IAQ and thermal comfort.

    Science.gov (United States)

    Heiselberg, P; Perino, M

    2010-04-01

    The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. Among the available ventilation strategies that are currently available, buoyancy driven, single-sided natural ventilation has proved to be very effective and can provide high air change rates for temperature and Indoor Air Quality (IAQ) control. However, to promote a wider distribution of these systems an improvement in the knowledge of their working principles is necessary. The present study analyses and presents the results of an experimental evaluation of airing performance in terms of ventilation characteristics, IAQ and thermal comfort. It includes investigations of the consequences of opening time, opening frequency, opening area and expected airflow rate, ventilation efficiency, thermal comfort and dynamic temperature conditions. A suitable laboratory test rig was developed to perform extensive experimental analyses of the phenomenon under controlled and repeatable conditions. The results showed that short-term window airing is very effective and can provide both acceptable IAQ and thermal comfort conditions in buildings. Practical Implications This study gives the necessary background and in-depth knowledge of the performance of window airing by single-sided natural ventilation necessary for the development of control strategies for window airing (length of opening period and opening frequency) for optimum IAQ and thermal comfort in naturally ventilated buildings.

  20. Nevada Test Site Waste Acceptance Criteria (NTSWAC)

    Energy Technology Data Exchange (ETDEWEB)

    NNSA/NSO Waste Management Project

    2008-06-01

    This document establishes the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, Nevada Test Site Waste Acceptance Criteria (NTSWAC). The NTSWAC provides the requirements, terms, and conditions under which the Nevada Test Site will accept low-level radioactive (LLW) and LLW Mixed Waste (MW) for disposal.

  1. Nevada Test Site Waste Acceptance Criteria (NTSWAC)

    International Nuclear Information System (INIS)

    NNSA/NSO Waste Management Project

    2008-01-01

    This document establishes the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, Nevada Test Site Waste Acceptance Criteria (NTSWAC). The NTSWAC provides the requirements, terms, and conditions under which the Nevada Test Site will accept low-level radioactive (LLW) and LLW Mixed Waste (MW) for disposal

  2. Impact of shade on outdoor thermal comfort—a seasonal field study in Tempe, Arizona

    Science.gov (United States)

    Middel, Ariane; Selover, Nancy; Hagen, Björn; Chhetri, Nalini

    2016-12-01

    Shade plays an important role in designing pedestrian-friendly outdoor spaces in hot desert cities. This study investigates the impact of photovoltaic canopy shade and tree shade on thermal comfort through meteorological observations and field surveys at a pedestrian mall on Arizona State University's Tempe campus. During the course of 1 year, on selected clear calm days representative of each season, we conducted hourly meteorological transects from 7:00 a.m. to 6:00 p.m. and surveyed 1284 people about their thermal perception, comfort, and preferences. Shade lowered thermal sensation votes by approximately 1 point on a semantic differential 9-point scale, increasing thermal comfort in all seasons except winter. Shade type (tree or solar canopy) did not significantly impact perceived comfort, suggesting that artificial and natural shades are equally efficient in hot dry climates. Globe temperature explained 51 % of the variance in thermal sensation votes and was the only statistically significant meteorological predictor. Important non-meteorological factors included adaptation, thermal comfort vote, thermal preference, gender, season, and time of day. A regression of subjective thermal sensation on physiological equivalent temperature yielded a neutral temperature of 28.6 °C. The acceptable comfort range was 19.1 °C-38.1 °C with a preferred temperature of 20.8 °C. Respondents exposed to above neutral temperature felt more comfortable if they had been in air-conditioning 5 min prior to the survey, indicating a lagged response to outdoor conditions. Our study highlights the importance of active solar access management in hot urban areas to reduce thermal stress.

  3. Effect of mode of operation on hydrogen production from glycerol at thermal neutral conditions: Thermodynamic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pairojpiriyakul, Thirasak; Soottitantawat, Apinan; Arpornwichanop, Amornchai; Assabumrungrat, Suttichai [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University (Thailand); Kiatkittipong, Worapon [Department of Chemical Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University (Thailand); Wiyaratn, Wisitsree [Department of Production Technology Education, Faculty of Industrial Education and Technology, King Mongkut' s University of Technology Thonburi (Thailand); Laosiripojana, Navadol [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi (Thailand); Croiset, Eric [Department of Chemical Engineering, University of Waterloo (Canada)

    2010-10-15

    Thermodynamic analysis of hydrogen production from glycerol under thermal neutral conditions is studied in this work. Heat requirement from the process can be achieved from the exothermic reaction of glycerol with oxygen in air fed to the system. Two modes of operation for air feeding are considered including (i) Single-feed mode in which air is fed in combination with water and glycerol to the reformer, and (ii) Split-feed mode in which air and part of glycerol is fed to a combustor in order to generate heat. The thermal neutral conditions are considered for two levels including Reformer and System levels. It was found that the H{sub 2} yield from both modes is not significantly different at the Reformer level. In contrast, the difference becomes more pronounced at the System level. Single-feed and Split-feed modes offer high H{sub 2} yield in low (600-900 K) and high (900-1200 K) temperature ranges, respectively. The maximum H{sub 2} yields are 5.67 (water to glycerol ratio, WGR = 12, oxygen to glycerol ratio, OGR = 0.37, T = 900 K, Split-feed mode), and 3.28 (WGR = 3, OGR = 1.40, T = 900 K, Single-feed mode), for the Reformer and System levels, respectively. The difference between H{sub 2} yields in both levels mainly arises from the huge heat demand for preheating feeds in the System level, and therefore, a higher amount of air is needed to achieve the thermal neutral condition. Split-feed mode is a favorable choice in term of H{sub 2} purity because the gas product is not diluted with N{sub 2} from the air. The use of pure O{sub 2} and afterburner products (ABP) stream were also considered at the System level. The maximum H{sub 2} yield becomes 3.75 (WGR = 5.21, OGR = 1.28, T = 900 K, Split-feed mode) at thermal neutral condition when utilizing heat from the ABP stream. Finally comparisons between the different modes and levels are addressed in terms of yield of by-products, and carbon formation. (author)

  4. Installation of PMV Operation Program in DDC Controller and Air Conditioning Control Using PMV Directly as Set Point

    Science.gov (United States)

    Haramoto, Ken-Ichi

    In general, air conditioning control in a building is operated mainly by indoor air temperature control. Although the operators of the machine in the building accepted a claim for indoor air temperature presented by the building inhabitants, the indoor conditions have been often too cool or warm. Therefore, in an attempt to create better thermal environments, the author paid attention to the PMV that is a thermal comfort index. And then, the possibility of air conditioning control using the PMV directly as the set point was verified by employing actual equipment in an air conditioning testing room and an office building. Prior to the execution of this control, the operation program of the PMV was installed in a DDC controller for the air conditioning control. And information from indoor sensors and so on was inputted to the controller, and the computed PMV was used as the feedback variable.

  5. Displacement compressors - acceptance tests

    CERN Document Server

    International Organization for Standardization. Geneva

    1996-01-01

    ISO 1217:2009 specifies methods for acceptance tests regarding volume rate of flow and power requirements of displacement compressors. It also specifies methods for testing liquid-ring type compressors and the operating and testing conditions which apply when a full performance test is specified.

  6. Experimental results of thermally controlled superconducting switches for high frequency operation

    International Nuclear Information System (INIS)

    Mulder, G.B.J.; IerAvest, D.; Tenkate, H.H.J.; Krooshoop, H.J.G.; Van de Klundert, L.

    1988-01-01

    The aim of this study is to develop thermally controlled switches which are to be used in superconducting rectifiers operating at a few hertz and 1 kA. Usually, the operating frequency of thermally controlled rectifiers is limited to about 0.1 Hz due to the thermal recovery times of the switches. The thermal switches have to satisfy two conditions which are specific for the application in a superconducting rectifier: a) they have to operate in the repetitive mode so beside short activation times, fast recovery times of the switches are equally important, b) the power required to effect and maintain the normal state of the switches should be low since it will determine the rectifier efficiency. To what extent these obviously conflicting demands can be satisfied depends on the material and geometry of the switch. This paper presents a theoretical model of the thermal behaviour of a switch. The calculations are compared with experimental results of several switches having recovery times between 40 and 200 ms. Also, the feasibility of such switches for application in superconducting rectifiers operating at a few hertz with an acceptable efficiency is demonstrated

  7. Evaluating local and overall thermal comfort in buildings using thermal manikins

    Energy Technology Data Exchange (ETDEWEB)

    Foda, E.

    2012-07-01

    Evaluation methods of human thermal comfort that are based on whole-body heat balance with its surroundings may not be adequate for evaluations in non-uniform thermal conditions. Under these conditions, the human body's segments may experience a wide range of room physical parameters and the evaluation of the local (segmental) thermal comfort becomes necessary. In this work, subjective measurements of skin temperature were carried out to investigate the human body's local responses due to a step change in the room temperature; and the variability in the body's local temperatures under different indoor conditions and exposures as well as the physiological steady state local temperatures. Then, a multi-segmental model of human thermoregulation was developed based on these findings to predict the local skin temperatures of individuals' body segments with a good accuracy. The model predictability of skin temperature was verified for steady state and dynamic conditions using measured data at uniform neutral, cold and warm as well as different asymmetric thermal conditions. The model showed very good predictability with average absolute deviation ranged from 0.3-0.8 K. The model was then implemented onto the control system of the thermal manikin 'THERMINATOR' to adjust the segmental skin temperature set-points based on the indoor conditions. This new control for the manikin was experimentally validated for the prediction of local and overall thermal comfort using the equivalent temperature measure. THERMINATOR with the new control mode was then employed in the evaluation of localized floor-heating system variants towards maximum energy efficiency. This aimed at illustrating a design strategy using the thermal manikin to find the optimum geometry and surface area of a floor-heater for a single seated person. Furthermore, a psychological comfort model that is based on local skin temperature was adapted for the use with the model of human

  8. Electro-thermal Modeling of Modern Power Devices for Studying Abnormal Operating Conditions

    DEFF Research Database (Denmark)

    Wu, Rui

    in industrial power electronic systems in the range above 10 kW. The failure of IGBTs can be generally classified as catastrophic failures and wear out failures. A wear out failure is mainly induced by accumulated degradation with time, while a catastrophic failure is triggered by a single-event abnormal....... The objective of this project has been to model and predict the electro-thermal behavior of IGBT power modules under abnormal conditions, especially short circuits. A thorough investigation on catastrophic failure modes and mechanisms of modern power semiconductor devices, including IGBTs and power diodes, has...

  9. Pregnancy planning and acceptance among Danish pregnant women

    DEFF Research Database (Denmark)

    Rasch, V; Knudsen, L B; Wielandt, H

    2001-01-01

    OBJECTIVE: To study how living conditions influence pregnancy planning and acceptance among Danish women. METHOD: A cross-sectional questionnaire study performed among 3516 pregnant women attending Odense University Hospital, Denmark. The study population consisted of women with spontaneous...... abortion, women with ectopic pregnancies, women attending antenatal care and women with induced abortion. They were divided into four groups: women with planned and accepted pregnancies (accepting planners, n=2137), women who accepted an initially unplanned pregnancy (accepting non-planners, n=1006), women...... who rejected an initially planned pregnancy (rejecting planners, n=31), and women with unplanned and rejected pregnancies (rejecting non-planners, n=342). The association between socio-economic characteristics and pregnancy planning and acceptance was evaluated by comparing accepting non...

  10. Time consistency conditions for acceptability measures, with an application to Tail Value at Risk

    NARCIS (Netherlands)

    Roorda, Berend; Schumacher, Hans

    2005-01-01

    An acceptability measure is a number that summarizes information on monetary outcomes of a given position in various scenarios, and that, depending on context, may be interpreted as a capital requirement or as a price. In a multiperiod setting, it is reasonable to require that an acceptability

  11. Robust Vehicle Detection under Various Environmental Conditions Using an Infrared Thermal Camera and Its Application to Road Traffic Flow Monitoring

    Directory of Open Access Journals (Sweden)

    Toshiyuki Nakamiya

    2013-06-01

    Full Text Available We have already proposed a method for detecting vehicle positions and their movements (henceforth referred to as “our previous method” using thermal images taken with an infrared thermal camera. Our experiments have shown that our previous method detects vehicles robustly under four different environmental conditions which involve poor visibility conditions in snow and thick fog. Our previous method uses the windshield and its surroundings as the target of the Viola-Jones detector. Some experiments in winter show that the vehicle detection accuracy decreases because the temperatures of many windshields approximate those of the exterior of the windshields. In this paper, we propose a new vehicle detection method (henceforth referred to as “our new method”. Our new method detects vehicles based on tires’ thermal energy reflection. We have done experiments using three series of thermal images for which the vehicle detection accuracies of our previous method are low. Our new method detects 1,417 vehicles (92.8% out of 1,527 vehicles, and the number of false detection is 52 in total. Therefore, by combining our two methods, high vehicle detection accuracies are maintained under various environmental conditions. Finally, we apply the traffic information obtained by our two methods to traffic flow automatic monitoring, and show the effectiveness of our proposal.

  12. Robust vehicle detection under various environmental conditions using an infrared thermal camera and its application to road traffic flow monitoring.

    Science.gov (United States)

    Iwasaki, Yoichiro; Misumi, Masato; Nakamiya, Toshiyuki

    2013-06-17

    We have already proposed a method for detecting vehicle positions and their movements (henceforth referred to as "our previous method") using thermal images taken with an infrared thermal camera. Our experiments have shown that our previous method detects vehicles robustly under four different environmental conditions which involve poor visibility conditions in snow and thick fog. Our previous method uses the windshield and its surroundings as the target of the Viola-Jones detector. Some experiments in winter show that the vehicle detection accuracy decreases because the temperatures of many windshields approximate those of the exterior of the windshields. In this paper, we propose a new vehicle detection method (henceforth referred to as "our new method"). Our new method detects vehicles based on tires' thermal energy reflection. We have done experiments using three series of thermal images for which the vehicle detection accuracies of our previous method are low. Our new method detects 1,417 vehicles (92.8%) out of 1,527 vehicles, and the number of false detection is 52 in total. Therefore, by combining our two methods, high vehicle detection accuracies are maintained under various environmental conditions. Finally, we apply the traffic information obtained by our two methods to traffic flow automatic monitoring, and show the effectiveness of our proposal.

  13. Plug-in hybrid electric vehicle LiFePO4 battery life implications of thermal management, driving conditions, and regional climate

    Science.gov (United States)

    Yuksel, Tugce; Litster, Shawn; Viswanathan, Venkatasubramanian; Michalek, Jeremy J.

    2017-01-01

    Battery degradation strongly depends on temperature, and many plug-in electric vehicle applications employ thermal management strategies to extend battery life. The effectiveness of thermal management depends on the design of the thermal management system as well as the battery chemistry, cell and pack design, vehicle system characteristics, and operating conditions. We model a plug-in hybrid electric vehicle with an air-cooled battery pack composed of cylindrical LiFePO4/graphite cells and simulate the effect of thermal management, driving conditions, regional climate, and vehicle system design on battery life. We estimate that in the absence of thermal management, aggressive driving can cut battery life by two thirds; a blended gas/electric-operation control strategy can quadruple battery life relative to an all-electric control strategy; larger battery packs can extend life by an order of magnitude relative to small packs used for all-electric operation; and batteries last 73-94% longer in mild-weather San Francisco than in hot Phoenix. Air cooling can increase battery life by a factor of 1.5-6, depending on regional climate and driving patterns. End of life criteria has a substantial effect on battery life estimates.

  14. NEVADA TEST SITE WASTE ACCEPTANCE CRITERIA

    International Nuclear Information System (INIS)

    U.S. DEPARTMENT OF ENERGY, NATIONAL NUCLEAR SECURITY ADMINISTRATION, NEVADA SITE OFFICE

    2005-01-01

    This document establishes the U. S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) waste acceptance criteria (WAC). The WAC provides the requirements, terms, and conditions under which the Nevada Test Site will accept low-level radioactive and mixed waste for disposal. Mixed waste generated within the State of Nevada by NNSA/NSO activities is accepted for disposal. It includes requirements for the generator waste certification program, characterization, traceability, waste form, packaging, and transfer. The criteria apply to radioactive waste received at the Nevada Test Site Area 3 and Area 5 Radioactive Waste Management Site for storage or disposal

  15. Induction of MHC-mismatched Mouse Lung Allograft Acceptance with Combined Donor Bone Marrow: Lung Transplant using a 12-Hour Nonmyeloablative Conditioning Regimen

    Science.gov (United States)

    Vulic, Ante; Panoskaltsis-Mortari, Angela; McDyer, John F.; Luznik, Leo

    2016-01-01

    Background Despite broad and intense conventional immunosuppression, long-term survival after lung transplantation lags behind that for other solid organ transplants, primarily because of allograft rejection. Therefore, new strategies to promote lung allograft acceptance are urgently needed. The purpose of the present study was to induce allograft tolerance with a protocol compatible with deceased donor organ utilization. Methods Using the MHC-mismatched mouse orthotopic lung transplant model, we investigated a conditioning regimen consisting of pretransplant T cell depletion, low dose total body irradiation and posttransplant (donor) bone marrow and splenocyte infusion followed by posttransplantation cyclophosphamide (PTTT-PTB/PTCy). Results Our results show that C57BL/6 recipients of BALB/c lung allografts undergoing this complete short-duration nonmyeloablative conditioning regimen had durable lung allograft acceptance. Mice that lacked 1 or more components of this regimen exhibited significant graft loss. Mechanistically, animals with lung allograft acceptance had established higher levels of donor chimerism, lymphocyte responses which were attenuated to donor antigens but maintained to third-party antigens, and clonal deletion of donor-reactive host Vβ T cells. Frequencies of Foxp3+ T regulatory cells were comparable in both surviving and rejected allografts implying that their perturbation was not a dominant cell-regulatory mechanism. Donor chimerism was indispensable for sustained tolerance, as evidenced by acute rejection of allografts in established chimeric recipients of PTTT-PTB/PTCy following a chimerism-ablating secondary recipient lymphocyte infusion. Conclusion Together, these data provide proof-of-concept for establishing lung allograft tolerance with tandem donor bone marrow transplantation (BMT) using a short-duration nonmyeloablative conditioning regimen and PTCy. PMID:27861294

  16. Numerical investigations of buoyancy-driven natural ventilation in a simple atrium building and its effect on the thermal comfort conditions

    International Nuclear Information System (INIS)

    Hussain, Shafqat; Oosthuizen, Patrick H.

    2012-01-01

    In the present study use of solar-assisted buoyancy-driven natural ventilation in a simple atrium building is explored numerically with particular emphasis on the thermal comfort conditions in the building. Initially various geometric configurations of the atrium space were considered in order to investigate airflows and temperature distributions in the building using a validated computational fluid dynamics (CFD) model. The Reynolds Averaged Navier–Stokes (RANS) modelling approach with the SST-k–ω turbulence model and the Discrete Transfer Radiation Model (DTRM) was used for the investigations. The steady-state governing equations were solved using a commercial CFD solver FLUENT © . From the numerical results obtained, it was noted that an atrium space integrated with a solar chimney would be a relatively better option to be used in an atrium building. In the geometry selected, the performance of the building in response to various changes in design parameters was investigated. The produced airflows and temperature distributions were then used to evaluate indoor thermal comfort conditions in terms of the thermal comfort indices, i.e. the well-known predicted mean vote (PMV) index, its modifications especially for natural ventilation, predicted percent dissatisfied (PPD) index and Percent dissatisfied (PD) factor due to draft. It was found that the thermal conditions in the occupied areas of the building developed as a result of the use of solar-assisted buoyancy-driven ventilation for the particular values of the design parameters selected are mostly in the comfortable zone. Finally, it is demonstrated that the proposed methodology leads to reliable thermal comfort predictions, while the effect of various design variables on the performance of the building is easily recognized. - Highlights: ► Numerical investigations were carried for the use of buoyancy-driven displacement ventilation in a simple atrium building. ► Effect of various atrium

  17. Agricultural utilization of industrial thermal effluents

    International Nuclear Information System (INIS)

    Guillermin, P.; Delmas, J.; Grauby, A.

    1976-01-01

    An assessment is made of the utilization of thermal effluent for agricultural purpose (viz. early vegetables, cereals, trees). Heated waters are being used in field experiments on soil heating, improvement of agricultural procedures and crop yields. Thermal pollution cannot be removed yet it is reduced to acceptable limits. New prospects are open to traditional agriculture, leading towards a more competitive industrial model [fr

  18. Investigating the adaptive model of thermal comfort for naturally ventilated school buildings in Taiwan

    Science.gov (United States)

    Hwang, Ruey-Lung; Lin, Tzu-Ping; Chen, Chen-Peng; Kuo, Nai-Jung

    2009-03-01

    Divergence in the acceptability to people in different regions of naturally ventilated thermal environments raises a concern over the extent to which the ASHRAE Standard 55 may be applied as a universal criterion of thermal comfort. In this study, the ASHRAE 55 adaptive model of thermal comfort was investigated for its applicability to a hot and humid climate through a long-term field survey performed in central Taiwan among local students attending 14 elementary and high schools during September to January. Adaptive behaviors, thermal neutrality, and thermal comfort zones are explored. A probit analysis of thermal acceptability responses from students was performed in place of the conventional linear regression of thermal sensation votes against operative temperature to investigate the limits of comfort zones for 90% and 80% acceptability; the corresponding comfort zones were found to occur at 20.1-28.4°C and 17.6-30.0°C, respectively. In comparison with the yearly comfort zones recommended by the adaptive model for naturally ventilated spaces in the ASHRAE Standard 55, those observed in this study differ in the lower limit for 80% acceptability, with the observed level being 1.7°C lower than the ASHRAE-recommended value. These findings can be generalized to the population of school children, thus providing information that can supplement ASHRAE Standard 55 in evaluating the thermal performance of naturally ventilated school buildings, particularly in hot-humid areas such as Taiwan.

  19. Thermal analysis of the modified Hallum Nuclear Power Facility cask using experimentally obtained thermal boundary conditions corresponding to an engulfing open pool fire

    International Nuclear Information System (INIS)

    Longenbaugh, R.S.; Sanchez, L.C.; Gregory, J.J.

    1987-08-01

    This report presents the two-dimensional heat transfer analysis of an open pool fire surrounding a modified radioactive materials transport cask. The cask is an older cask that was used by the Hallum Nuclear Power Facility (HNPF). The HNPF cask did not have a neutron shielding region but was modified to include one for testing purposes. Analysis of the thermal effects of an engulfing open pool fire was performed with the use of the heat transfer code Q/TRAN, which had previously been used in thermal benchmarking problems for spent nuclear fuel casks. Boundary condition data for the analysis were derived from experimental open pool fire tests of large-scale calorimeter test articles performed at SNL that produced information about cask surface heat flux versus surface temperature relationships. Data analysis was directed toward a determination of the thermal response of the cask, particularly the extent of lead melt since lead is used within the HNPF cask's gamma-shielding region. Parameters, such as surface emissivity and internal heat generation rate, can affect the results of the thermal analysis which control the amount of lead melt. A parameter sensitivity analysis was performed using a one-dimensional model to describe how surface emissivity and internal heat generation rates affect the temperature distribution within the cask. The information from this analysis was used to determine the range of parameters for the two-dimensional thermal analysis. 13 refs., 57 figs., 8 tabs

  20. System and method of providing quick thermal comfort with reduced energy by using directed spot conditioning

    Science.gov (United States)

    Wang, Mingyu; Kadle, Prasad S.; Ghosh, Debashis; Zima, Mark J.; Wolfe, IV, Edward; Craig, Timothy D

    2016-10-04

    A heating, ventilation, and air conditioning (HVAC) system and a method of controlling a HVAC system that is configured to provide a perceived comfortable ambient environment to an occupant seated in a vehicle cabin. The system includes a nozzle configured to direct an air stream from the HVAC system to the location of a thermally sensitive portion of the body of the occupant. The system also includes a controller configured to determine an air stream temperature and an air stream flow rate necessary to establish the desired heat supply rate for the sensitive portion and provide a comfortable thermal environment by thermally isolating the occupant from the ambient vehicle cabin temperature. The system may include a sensor to determine the location of the sensitive portion. The nozzle may include a thermoelectric device to heat or cool the air stream.

  1. Influence of the thermal boundary conditions on the flow and the isotope separation of a gas centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Novelli, P.

    1981-11-01

    The axisymmetric steady gas flow in a so called thermally driven ultracentrifuge at total reflux and its /sup 235/UF/sub 6/-/sup 238/UF/sub 6/- separating characteristics are treated numerically. The top and the bottom end-caps are thermally conducting and kept at temperatures generally depending on radius. Regarding the side-wall temperature conditions, three cases will be considered: (1) insulated side-wall; (2) side-wall at constant temperature; (3) linear temperature profile continuously joining the end-plate temperatures. 20 figures, 2 tables.

  2. Multiregion, multigroup collision probability method with white boundary condition for light water reactor thermalization calculations

    International Nuclear Information System (INIS)

    Ozgener, B.; Ozgener, H.A.

    2005-01-01

    A multiregion, multigroup collision probability method with white boundary condition is developed for thermalization calculations of light water moderated reactors. Hydrogen scatterings are treated by Nelkin's kernel while scatterings from other nuclei are assumed to obey the free-gas scattering kernel. The isotropic return (white) boundary condition is applied directly by using the appropriate collision probabilities. Comparisons with alternate numerical methods show the validity of the present formulation. Comparisons with some experimental results indicate that the present formulation is capable of calculating disadvantage factors which are closer to the experimental results than alternative methods

  3. Thermal convection in a closed cavity in zero-gravity space conditions with stationary magnetic forces

    International Nuclear Information System (INIS)

    Lyubimova, T; Mailfert, A

    2013-01-01

    The paper deals with the investigation of thermo-magnetic convection in a paramagnetic liquid subjected to a non-uniform magnetic field in weightlessness conditions. Indeed, in zero-g space conditions such as realized in International Space Station (ISS), or in artificial satellite, or in free-flight space vessels, the classical thermo-gravitational convection in fluid disappears. In any cases, it may be useful to restore the convective thermal exchange inside fluids such as liquid oxygen. In this paper, the restoration of heat exchange by the way of creation of magnetic convection is numerically studied.

  4. Influence of Thermal Treatment Conditions on the Properties of Dental Silicate Cements

    Directory of Open Access Journals (Sweden)

    Georgeta Voicu

    2016-02-01

    Full Text Available In this study the sol-gel process was used to synthesize a precursor mixture for the preparation of silicate cement, also called mineral trioxide aggregate (MTA cement. This mixture was thermally treated under two different conditions (1400 °C/2 h and 1450 °C/3 h followed by rapid cooling in air. The resulted material (clinker was ground for one hour in a laboratory planetary mill (v = 150 rot/min, in order to obtain the MTA cements. The setting time and mechanical properties, in vitro induction of apatite formation by soaking in simulated body fluid (SBF and cytocompatibility of the MTA cements were assessed in this study. The hardening processes, nature of the reaction products and the microstructural characteristics were also investigated. The anhydrous and hydrated cements were characterized by different techniques e.g., X-ray diffraction (XRD, scanning electron microscopy (SEM, infrared spectroscopy (FT-IR and thermal analysis (DTA-DTG-TG. The setting time of the MTA cement obtained by thermal treatment at 1400 °C/2 h (MTA1 was 55 min and 15 min for the MTA cement obtained at 1450 °C/3 h (MTA2. The compressive strength values were 18.5 MPa (MTA1 and 22.9 MPa (MTA2. Both MTA cements showed good bioactivity (assessed by an in vitro test, good cytocompatibility and stimulatory effect on the proliferation of cells.

  5. Thermal denaturation of sunflower globulins in low moisture conditions

    International Nuclear Information System (INIS)

    Rouilly, A.; Orliac, O.; Silvestre, F.; Rigal, L.

    2003-01-01

    DSC analysis in pressure resisting pans of sunflower oil cake makes appear the endothermic peak of sunflower globulins denaturation. Its temperature decreases from 189.5 to 119.9 deg. C while the corresponding enthalpy increases from 2.6 to 3.3 J/g of sample, or from 6.7 to 12.2 J/g of dry protein, when the samples moisture content varies from 0 to 30.0% of the total weight. The plot of the denaturation temperature versus the moisture content is not linear but has a rounded global shape and seems to follow the hydration behavior of the proteins, modeled with the sorption isotherm. As it can be seen on scanning electron microscopy (SEM) micrographs, protein corpuscles 'melt' after such a thermal treatment and large aggregates form by coagulation. Moisture dependence of the 'fusion' temperature of native proteic organization, in low moisture conditions, offers so a new characterization method for the use of vegetable proteins in agro-materials

  6. Thermal denaturation of sunflower globulins in low moisture conditions

    Energy Technology Data Exchange (ETDEWEB)

    Rouilly, A.; Orliac, O.; Silvestre, F.; Rigal, L

    2003-03-05

    DSC analysis in pressure resisting pans of sunflower oil cake makes appear the endothermic peak of sunflower globulins denaturation. Its temperature decreases from 189.5 to 119.9 deg. C while the corresponding enthalpy increases from 2.6 to 3.3 J/g of sample, or from 6.7 to 12.2 J/g of dry protein, when the samples moisture content varies from 0 to 30.0% of the total weight. The plot of the denaturation temperature versus the moisture content is not linear but has a rounded global shape and seems to follow the hydration behavior of the proteins, modeled with the sorption isotherm. As it can be seen on scanning electron microscopy (SEM) micrographs, protein corpuscles 'melt' after such a thermal treatment and large aggregates form by coagulation. Moisture dependence of the 'fusion' temperature of native proteic organization, in low moisture conditions, offers so a new characterization method for the use of vegetable proteins in agro-materials.

  7. An inverse method for calculation of thermal inertia and heat gain in air conditioning and refrigeration systems

    International Nuclear Information System (INIS)

    Fayazbakhsh, M.A.; Bagheri, F.; Bahrami, M.

    2015-01-01

    Highlights: • An inverse method is proposed to calculate thermal inertia in HVAC-R systems. • Real-time thermal loads are estimated using the proposed intelligent algorithm. • Calculation algorithm is validated with on-site measurements. • Freezer duty cycle data are extracted only based on temperature measurements. - Abstract: A new inverse method is proposed for estimation of thermal inertia and heat gain in air conditioning and refrigeration systems using on-site temperature measurements. The method is applied on a walk-in freezer room of a restaurant in Surrey, British Columbia, Canada during one week of its regular operation. The thermal inertia and instantaneous heat gain are calculated and the results are validated using actual information of the materials inside the freezer room. The proposed method can be implemented in intelligent control systems designed for new and existing HVAC-R systems to improve their overall energy efficiency and reduce their environmental impacts

  8. Pregnancy planning and acceptance among Danish pregnant women

    DEFF Research Database (Denmark)

    Rasch, V; Knudsen, L B; Wielandt, H

    2001-01-01

    OBJECTIVE: To study how living conditions influence pregnancy planning and acceptance among Danish women. METHOD: A cross-sectional questionnaire study performed among 3516 pregnant women attending Odense University Hospital, Denmark. The study population consisted of women with spontaneous......-planners with accepting planners and by comparing rejecting planners with rejecting non-planners. The variables studied comprise age, number of children, partner relationship, education, occupation, economic situation and contraceptives. RESULTS: The characteristics of accepting non-planners and accepting planners were...... in accordance and in contrast to those of rejecting planners and in particular of rejecting non-planners. The contraceptive prevalence rate among accepting non-planners was 15%. Among rejecting non-planners the same figure was 51%. CONCLUSION: Accepting non-planners seemed to be in a situation which could...

  9. 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...

  10. TPX vacuum vessel transient thermal and stress conditions

    International Nuclear Information System (INIS)

    Feldshteyn, Y.; Dinkevich, S.; Feng, T.; Majumder, D.

    1995-01-01

    The TPX vacuum vessel provides the vacuum boundary for the plasma and the mechanical support for the internal components. Another function of the vacuum vessel is to contain neutron shielding water in the double wall space during normal operation. This double wall space serves as a heat reservoir for the entire vacuum vessel during bakeout. The vacuum vessel and the internal components are subjected to thermal stresses induced by a nonuniform temperature distribution within the structure during bakeout. A successful Conceptual Design Review in March 1993 has established superheated steam as the heating source of the vacuum vessel. A transient bakeout mode of the vacuum vessel and in-vessel components has been analyzed to evaluate transient period duration, proper temperature level, actual thermal stresses and performance of the steam equipment. Thermally, the vacuum vessel structure may be considered as an adiabatic system because it is perfectly insulated by the strong surrounding vacuum and multiple layers of superinsulation. Important aspects of the analysis are described herein

  11. Thermal comfort in air-conditioned buildings in hot and humid climates--why are we not getting it right?

    Science.gov (United States)

    Sekhar, S C

    2016-02-01

    While there are plenty of anecdotal experiences of overcooled buildings in summer, evidence from field studies suggests that there is indeed an issue of overcooling in tropical buildings. The findings suggest that overcooled buildings are not a consequence of occupant preference but more like an outcome of the HVAC system design and operation. Occupants' adaptation in overcooled indoor environments through additional clothing cannot be regarded as an effective mitigating strategy for cold thermal discomfort. In the last two decades or so, several field studies and field environmental chamber studies in the tropics provided evidence for occupants' preference for a warmer temperature with adaptation methods such as elevated air speeds. It is important to bear in mind that indoor humidity levels are not compromised as they could have an impact on the inhaled air condition that could eventually affect perceived air quality. This review article has attempted to track significant developments in our understanding of the thermal comfort issues in air-conditioned office and educational buildings in hot and humid climates in the last 25 years, primarily on occupant preference for thermal comfort in such climates. The issue of overcooled buildings, by design intent or otherwise, is discussed in some detail. Finally, the article has explored some viable adaptive thermal comfort options that show considerable promise for not only improving thermal comfort in tropical buildings but are also energy efficient and could be seen as sustainable solutions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Using Upper Extremity Skin Temperatures to Assess Thermal Comfort in Office Buildings in Changsha, China.

    Science.gov (United States)

    Wu, Zhibin; Li, Nianping; Cui, Haijiao; Peng, Jinqing; Chen, Haowen; Liu, Penglong

    2017-09-21

    Existing thermal comfort field studies are mainly focused on the relationship between the indoor physical environment and the thermal comfort. In numerous chamber experiments, physiological parameters were adopted to assess thermal comfort, but the experiments' conclusions may not represent a realistic thermal environment due to the highly controlled thermal environment and few occupants. This paper focuses on determining the relationships between upper extremity skin temperatures (i.e., finger, wrist, hand and forearm) and the indoor thermal comfort. Also, the applicability of predicting thermal comfort by using upper extremity skin temperatures was explored. Field studies were performed in office buildings equipped with split air-conditioning (SAC) located in the hot summer and cold winter (HSCW) climate zone of China during the summer of 2016. Psychological responses of occupants were recorded and physical and physiological factors were measured simultaneously. Standard effective temperature (SET*) was used to incorporate the effect of humidity and air velocity on thermal comfort. The results indicate that upper extremity skin temperatures are good indicators for predicting thermal sensation, and could be used to assess the thermal comfort in terms of physiological mechanism. In addition, the neutral temperature was 24.7 °C and the upper limit for 80% acceptability was 28.2 °C in SET*.

  13. Using Upper Extremity Skin Temperatures to Assess Thermal Comfort in Office Buildings in Changsha, China

    Directory of Open Access Journals (Sweden)

    Zhibin Wu

    2017-09-01

    Full Text Available Existing thermal comfort field studies are mainly focused on the relationship between the indoor physical environment and the thermal comfort. In numerous chamber experiments, physiological parameters were adopted to assess thermal comfort, but the experiments’ conclusions may not represent a realistic thermal environment due to the highly controlled thermal environment and few occupants. This paper focuses on determining the relationships between upper extremity skin temperatures (i.e., finger, wrist, hand and forearm and the indoor thermal comfort. Also, the applicability of predicting thermal comfort by using upper extremity skin temperatures was explored. Field studies were performed in office buildings equipped with split air-conditioning (SAC located in the hot summer and cold winter (HSCW climate zone of China during the summer of 2016. Psychological responses of occupants were recorded and physical and physiological factors were measured simultaneously. Standard effective temperature (SET* was used to incorporate the effect of humidity and air velocity on thermal comfort. The results indicate that upper extremity skin temperatures are good indicators for predicting thermal sensation, and could be used to assess the thermal comfort in terms of physiological mechanism. In addition, the neutral temperature was 24.7 °C and the upper limit for 80% acceptability was 28.2 °C in SET*.

  14. Impact of shade on outdoor thermal comfort-a seasonal field study in Tempe, Arizona.

    Science.gov (United States)

    Middel, Ariane; Selover, Nancy; Hagen, Björn; Chhetri, Nalini

    2016-12-01

    Shade plays an important role in designing pedestrian-friendly outdoor spaces in hot desert cities. This study investigates the impact of photovoltaic canopy shade and tree shade on thermal comfort through meteorological observations and field surveys at a pedestrian mall on Arizona State University's Tempe campus. During the course of 1 year, on selected clear calm days representative of each season, we conducted hourly meteorological transects from 7:00 a.m. to 6:00 p.m. and surveyed 1284 people about their thermal perception, comfort, and preferences. Shade lowered thermal sensation votes by approximately 1 point on a semantic differential 9-point scale, increasing thermal comfort in all seasons except winter. Shade type (tree or solar canopy) did not significantly impact perceived comfort, suggesting that artificial and natural shades are equally efficient in hot dry climates. Globe temperature explained 51 % of the variance in thermal sensation votes and was the only statistically significant meteorological predictor. Important non-meteorological factors included adaptation, thermal comfort vote, thermal preference, gender, season, and time of day. A regression of subjective thermal sensation on physiological equivalent temperature yielded a neutral temperature of 28.6 °C. The acceptable comfort range was 19.1 °C-38.1 °C with a preferred temperature of 20.8 °C. Respondents exposed to above neutral temperature felt more comfortable if they had been in air-conditioning 5 min prior to the survey, indicating a lagged response to outdoor conditions. Our study highlights the importance of active solar access management in hot urban areas to reduce thermal stress.

  15. Energy metrics of photovoltaic/thermal and earth air heat exchanger integrated greenhouse for different climatic conditions of India

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, Sujata; Tiwari, G.N. [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

    2010-10-15

    In this paper, a study is carried out to evaluate the annual thermal and exergy performance of a photovoltaic/thermal (PV/T) and earth air heat exchanger (EAHE) system, integrated with a greenhouse, located at IIT Delhi, India, for different climatic conditions of Srinagar, Mumbai, Jodhpur, New Delhi and Bangalore. A comparison is made of various energy metrics, such as energy payback time (EPBT), electricity production factor (EPF) and life cycle conversion efficiency (LCCE) of the system by considering four weather conditions (a-d type) for five climatic zones. The embodied energy and annual energy outputs have been used for evaluation of the energy metrics. The annual overall thermal energy, annual electrical energy savings and annual exergy was found to be best for the climatic condition of Jodhpur at 29,156.8 kWh, 1185 kWh and 1366.4 kWh, respectively when compared with other weather stations covered in the study, due to higher solar intensity I and sunshine hours, and is lowest for Srinagar station. The results also showed that energy payback time for Jodhpur station is lowest at 16.7 years and highest for Srinagar station at 21.6 years. Electricity production factor (EPF) is highest for Jodhpur, i.e. 2.04 and Life cycle conversion efficiency (LCCE) is highest for Srinagar station. It is also observed that LCCE increases with increase in life cycle. (author)

  16. Thermal Control Subsystem Design for the Avionics of a Space Station Payload

    Science.gov (United States)

    Moran, Matthew E.

    1996-01-01

    A case study of the thermal control subsystem development for a space based payload is presented from the concept stage through preliminary design. This payload, the Space Acceleration Measurement System 2 (SAMS-2), will measure the acceleration environment at select locations within the International Space Station. Its thermal control subsystem must maintain component temperatures within an acceptable range over a 10 year life span, while restricting accessible surfaces to touch temperature limits and insuring fail safe conditions in the event of loss of cooling. In addition to these primary design objectives, system level requirements and constraints are imposed on the payload, many of which are driven by multidisciplinary issues. Blending these issues into the overall system design required concurrent design sessions with the project team, iterative conceptual design layouts, thermal analysis and modeling, and hardware testing. Multiple tradeoff studies were also performed to investigate the many options which surfaced during the development cycle.

  17. Effects of source, water conditioning and thermal treatment on ...

    African Journals Online (AJOL)

    at 15 % moisture content amounting to 61.3 MJ was the optimum thermal treatment for achieving germination of 69 %. R. heudelotii seeds soaked in water for 15 days at moisture content of 24 % over dry weight followed by thermal treatment improved germination by 22 %. The highest germination of 79 % was obtained for ...

  18. Influence of Urban Microclimate on Air-Conditioning Energy Needs and Indoor Thermal Comfort in Houses

    Directory of Open Access Journals (Sweden)

    Feng-Chi Liao

    2015-01-01

    Full Text Available A long-term climate measurement was implemented in the third largest city of Taiwan, for the check of accuracy of morphing approach on generating the hourly data of urban local climate. Based on observed and morphed meteorological data, building energy simulation software EnergyPlus was used to simulate the cooling energy consumption of an air-conditioned typical flat and the thermal comfort level of a naturally ventilated typical flat. The simulated results were used to quantitatively discuss the effect of urban microclimate on the energy consumption as well as thermal comfort of residential buildings. The findings of this study can serve as a reference for city planning and energy management divisions to study urban sustainability strategies in the future.

  19. Dos and Donts for Conditional Acceptance of Nonconforming Supplies or Services

    Science.gov (United States)

    2016-06-01

    credit for an on-time delivery. Was this in the government’s best interest? To answer this ques - tion, we need to review FAR 46.407 (c)(1), which...acceptance of a nonconforming item with a critical noncon- formance in appropriate circumstances such as “ economy or urgency,” FAR 46.407(c)(2

  20. Dynamic thermal reaction analysis of wall structures in various cooling operation conditions

    International Nuclear Information System (INIS)

    Yan, Biao; Long, Enshen; Meng, Xi

    2015-01-01

    Highlights: • Four different envelop structures are separately built in the same test building. • Cooling temperature and operation time were chosen as perturbations. • State Space Method is used to analyze the influence of wall sequence order. • The numerical models are validated by the comparisons of theory and test results. • The contrast of temperature change of different envelop structures was stark. - Abstract: This paper proposes a methodology of performance assessing of envelops under different cooling operation conditions, by focusing on indoor temperature change and dynamic thermal behavior performance of walls. To obtain a general relationship between the thermal environment change and the reaction of envelop, variously insulated walls made with the same insulation material are separately built in the same wall of a testing building with the four different structures, namely self-heat insulation (full insulation material), exterior insulation, internal insulation and intermediate insulation. The advantage of this setting is that the test targets are exposed to the same environmental variables, and the tests results are thus comparable. The target responses to two types of perturbations, cooling temperature and operation time were chosen as the important variations in the tests. Parameters of cooling set temperature of 22 °C and 18 °C, operation and restoring time 10 min and 15 min are set in the test models, and discussed with simulation results respectively. The results reveal that the exterior insulation and internal insulation are more sensitive to thermal environment change than self-heat insulation and intermediate insulation.

  1. Fatigue evaluation of piping connections under thermal transients

    International Nuclear Information System (INIS)

    Aquino, C.T.E. de; Maneschy, J.E.

    1993-01-01

    In designing nuclear power plant piping, thermal transients, caused by non-steady operation conditions, should be considered. These events may reduce considerably the lifetime of the pipes, creating the necessity of using structural elements designed in such a way to minimize the acting thermal stresses. Typical examples of the usage of these elements are the connections between pipes of small and large diameters, in which it is usually used a weldolet. Nevertheless, in some situations, the thermal stresses caused by the transients are greater than the allowable limits, being, in this case, an alternative for best results, the introduction of a special fitting replacing the weldolet. Such a fitting is designed in a way to permit a better distribution of the stresses, reducing its maximum value to acceptable levels. This paper intends to present a fatigue evaluation of a connection, using the above mentioned fitting, when subjected to a load expressed in terms of a step thermal gradient, varying from 263 deg to 40 deg C. Two different methodologies are used in this analysis: (a) Determination of the temperature distribution from the heat transfer equations for piping, being the stresses calculated according to ASME III NB-3600. (b) Thermal and stress analyses using axisymmetric elements, according to the rules presented at ASME III NB-3200. In the first case, named simplified analysis, the computer code used is the PIPESTRESS, while in the second case, the ANSYS program was adopted

  2. A questionnaire survey on sleeping thermal environment and bedroom air conditioning in high-rise residences in Hong Kong

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Z. [Institute of Heating, Ventilation, Air Conditioning and Gas Engineering, Tongji University, Shanghai (China); Deng, S. [Department of Building Services Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR (China)

    2006-07-01

    This paper reports on the results of a questionnaire survey on sleeping thermal environment and bedroom air conditioning in high-rise residential buildings in Hong Kong. The survey aimed at investigating the current situation of sleeping thermal environment and bedroom air conditioning, in order to gather relevant background information to develop strategies for bedroom air conditioning in the subtropics. It focused on the use patterns and types of bedroom air conditioning systems used, human factors such as the use of bedding and sleep wear during sleep, preference for indoor air temperature settings in bedrooms, ventilation control at nighttime with room air conditioner (RAC) turned on, etc. The results of the survey showed that most of the respondents would prefer a relatively low indoor air temperature at below 24 {sup o}C. Most of the respondents might however not be satisfied with the indoor air quality (IAQ) in bedrooms in Hong Kong. On the other hand, 68% of the respondents did not use any ventilation control intentionally during their sleep with their RACs turned on. A lack of knowledge of the ventilation control devices provided on window type room air conditioners (WRACs) indicated an urgent need for user education. (author)

  3. Management applications for thermal IR imagery of lake processes

    Science.gov (United States)

    Whipple, J. M.; Haynes, R. B.

    1971-01-01

    A thermal infrared scanning program was conducted in the Lake Ontario Basin region in an effort to determine: (1) limonologic data that could be collected by remote sensing techniques, and (2) local interest in and routine use of such data in water management programs. Difficulties encountered in the development of an infrared survey program in New York suggest that some of the major obstacles to acceptance of remotely sensed data for routine use are factors of psychology rather than technology. Also, terminology used should suit the measurement technique in order to encourage acceptance of the surface thermal data obtained.

  4. Thermal behavior and failure mechanism of lithium ion cells during overcharge under adiabatic conditions

    International Nuclear Information System (INIS)

    Ye, Jiana; Chen, Haodong; Wang, Qingsong; Huang, Peifeng; Sun, Jinhua; Lo, Siuming

    2016-01-01

    Highlights: • The modified adiabatic method is used to measure the heat generation under overcharge. • Side reactions contribute 80% heat to thermal runaway in the cases with cycling rate below 1.0 C. • The inflection and maximum voltages increase linearly with the increasing current rates. • The decomposed products of cathode materials are soluble with that of SiO_x. • Lithium plating on anode is due to changes of distance between the cathode and anode. - Abstract: Cells in battery packs are easily overcharged when battery management system (BMS) is out of order, causing thermal runaway. However, the traditional calorimetry could not estimate dynamic overcharging heat release. In this study, commercial LiCoO_2 + Li(Ni_0_._5Co_0_._2Mn_0_._3)O_2/C + SiO_x cells are employed to investigate the dynamic thermal behaviors during overcharge under adiabatic condition by combining a multi-channel battery cycler with an accelerating rate calorimeter. The results indicate that overcharging with galvanostatic - potentiostatic - galvanostatic regime is more dangerous than that with galvanostatic way. Side reactions contribute 80% heat to thermal runaway in cases below 1.0 C charging rate. To prevent the thermal runaway, the effective methods should be taken within 2 min to cool down the batteries as soon as the cells pass inflection point voltage. Hereinto, the inflection and maximum voltages increase linearly with the increasing current rates. By scanning electron microscope and energy dispersive spectrometer, the decomposed products of cathode materials are suspected to be soluble with SiOx. The overcharge induced decomposition reaction of Li(Ni_0_._5Co_0_._2Mn_0_._3)O_2 is also proposed. These results can provide support for the safety designs of lithium ion batteries and BMS.

  5. A methodology for on-line calculation of temperature and thermal stress under non-linear boundary conditions

    International Nuclear Information System (INIS)

    Botto, D.; Zucca, S.; Gola, M.M.

    2003-01-01

    In the literature many works have been written dealing with the task of on-line calculation of temperature and thermal stress for machine components and structures, in order to evaluate fatigue damage accumulation and estimate residual life. One of the most widespread methodologies is the Green's function technique (GFT), by which machine parameters such as fluid temperatures, pressures and flow rates are converted into metal temperature transients and thermal stresses. However, since the GFT is based upon the linear superposition principle, it cannot be directly used in the case of varying heat transfer coefficients. In the present work, a different methodology is proposed, based upon CMS for temperature transient calculation and upon the GFT for the related thermal stress evaluation. This new approach allows variable heat transfer coefficients to be accounted for. The methodology is applied for two different case studies, taken from the literature: a thick pipe and a nozzle connected to a spherical head, both subjected to multiple convective boundary conditions

  6. Thermal decomposition of hydroxylamine: Isoperibolic calorimetric measurements at different conditions

    International Nuclear Information System (INIS)

    Adamopoulou, Theodora; Papadaki, Maria I.; Kounalakis, Manolis; Vazquez-Carreto, Victor; Pineda-Solano, Alba; Wang, Qingsheng; Mannan, M.Sam

    2013-01-01

    Highlights: • Hydroxylamine thermal decomposition enthalpy was measured using larger quantities. • The rate at which heat is evolved depends on hydroxylamine concentration. • Decomposition heat is strongly affected by the conditions and the selected baseline. • The need for enthalpy measurements using a larger reactant mass is pinpointed. • Hydroxylamine decomposition in the presence of argon is much faster than in air. -- Abstract: Thermal decomposition of hydroxylamine, NH 2 OH, was responsible for two serious accidents. However, its reactive behavior and the synergy of factors affecting its decomposition are not being understood. In this work, the global enthalpy of hydroxylamine decomposition has been measured in the temperature range of 130–150 °C employing isoperibolic calorimetry. Measurements were performed in a metal reactor, employing 30–80 ml solutions containing 1.4–20 g of pure hydroxylamine (2.8–40 g of the supplied reagent). The measurements showed that increased concentration or temperature, results in higher global enthalpies of reaction per unit mass of reactant. At 150 °C, specific enthalpies as high as 8 kJ per gram of hydroxylamine were measured, although in general they were in the range of 3−5 kJ g −1 . The accurate measurement of the generated heat was proven to be a cumbersome task as (a) it is difficult to identify the end of decomposition, which after a fast initial stage, proceeds very slowly, especially at lower temperatures and (b) the environment of gases affects the reaction rate

  7. Thermal decomposition of hydroxylamine: Isoperibolic calorimetric measurements at different conditions

    Energy Technology Data Exchange (ETDEWEB)

    Adamopoulou, Theodora [Department of Environmental and Natural Resources Management, University of Western Greece (formerly of University of Ioannina), Seferi 2, Agrinio GR30100 (Greece); Papadaki, Maria I., E-mail: mpapadak@cc.uoi.gr [Department of Environmental and Natural Resources Management, University of Western Greece (formerly of University of Ioannina), Seferi 2, Agrinio GR30100 (Greece); Kounalakis, Manolis [Department of Environmental and Natural Resources Management, University of Western Greece (formerly of University of Ioannina), Seferi 2, Agrinio GR30100 (Greece); Vazquez-Carreto, Victor; Pineda-Solano, Alba [Mary Kay O’Connor Process Safety Center, Artie McFerrin Department of Chemical Engineering, Texas A and M University, College Station, TX 77843 (United States); Wang, Qingsheng [Department of Fire Protection and Safety and Department of Chemical Engineering, Oklahoma State University, 494 Cordell South, Stillwater, OK 74078 (United States); Mannan, M.Sam [Mary Kay O’Connor Process Safety Center, Artie McFerrin Department of Chemical Engineering, Texas A and M University, College Station, TX 77843 (United States)

    2013-06-15

    Highlights: • Hydroxylamine thermal decomposition enthalpy was measured using larger quantities. • The rate at which heat is evolved depends on hydroxylamine concentration. • Decomposition heat is strongly affected by the conditions and the selected baseline. • The need for enthalpy measurements using a larger reactant mass is pinpointed. • Hydroxylamine decomposition in the presence of argon is much faster than in air. -- Abstract: Thermal decomposition of hydroxylamine, NH{sub 2}OH, was responsible for two serious accidents. However, its reactive behavior and the synergy of factors affecting its decomposition are not being understood. In this work, the global enthalpy of hydroxylamine decomposition has been measured in the temperature range of 130–150 °C employing isoperibolic calorimetry. Measurements were performed in a metal reactor, employing 30–80 ml solutions containing 1.4–20 g of pure hydroxylamine (2.8–40 g of the supplied reagent). The measurements showed that increased concentration or temperature, results in higher global enthalpies of reaction per unit mass of reactant. At 150 °C, specific enthalpies as high as 8 kJ per gram of hydroxylamine were measured, although in general they were in the range of 3−5 kJ g{sup −1}. The accurate measurement of the generated heat was proven to be a cumbersome task as (a) it is difficult to identify the end of decomposition, which after a fast initial stage, proceeds very slowly, especially at lower temperatures and (b) the environment of gases affects the reaction rate.

  8. Internal thermotopography and shifts in general thermal balance in man under special heat transfer conditions

    Science.gov (United States)

    Gorodinskiy, S. M.; Gramenitskiy, P. M.; Kuznets, Y. I.; Ozerov, O. Y.; Yakovleva, E. V.; Groza, P.; Kozlovskiy, S.; Naremski, Y.

    1974-01-01

    Thermal regulation for astronauts working in pressure suits in open space provides for protection by a system of artificial heat removal and compensation to counteract possible changes in the heat regulating function of the human body that occur under the complex effects of space flight conditions. Most important of these factors are prolonged weightlessness, prolonged limitation of motor activity, and possible deviations of microclimatic environmental parameters.

  9. Nevada Test Site Waste Acceptance Criteria, December 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    This document establishes the US Department of Energy, Nevada Operations Office waste acceptance criteria. The waste acceptance criteria provides the requirements, terms, and conditions under which the Nevada Test Site will accept low-level radioactive waste and mixed waste for disposal. It includes requirements for the generator waste certification program, characterization, traceability, waste form, packaging, and transfer. The criteria apply to radioactive waste received at the Nevada Test Site Area 3 and Area 5 Radioactive Waste Management Sites for storage or disposal.

  10. Nevada Test Site Waste Acceptance Criteria, December 2000

    International Nuclear Information System (INIS)

    2000-01-01

    This document establishes the US Department of Energy, Nevada Operations Office waste acceptance criteria. The waste acceptance criteria provides the requirements, terms, and conditions under which the Nevada Test Site will accept low-level radioactive waste and mixed waste for disposal. It includes requirements for the generator waste certification program, characterization, traceability, waste form, packaging, and transfer. The criteria apply to radioactive waste received at the Nevada Test Site Area 3 and Area 5 Radioactive Waste Management Sites for storage or disposal

  11. Thermal conditions of the grape growing season within the North-Eastern steppe land of Ukraine (on the example of Kharkiv region

    Directory of Open Access Journals (Sweden)

    Борис Шуліка

    2016-10-01

    Full Text Available The article analyzes the results of the thermal conditions observations within the North-Eastern steppe land of Ukraine as one of the most important factors for successful cultivation of grapes, thus providing crop productivity. Considering the effect of thermal factors, it can be noted that the intensity and speed of life processes of plants are well- defined under temperature conditions only in the circumstances where other environmental factors are not limited. The thermal regime was initially taken into account in practice in XVII century. In XIX century the agro-climatic areas to grow grapes were determined in North-Eastern steppe land of Ukraine. Detailed studies of agro-climatic conditions of specific areas can more thoroughly to make conclusions and recommendations for the cultivation of grapes as a whole in the territory, and specifically in those areas were given. In studying the thermal balance of the territory the average and extreme temperature should be paid attention to. Characteristic features of the thermal regime are given in this paper based on the study of atmospheric phenomena, geomorphology and territories with radiation influence and water flow regime. Thermal treatment is subjected to anthropogenic influence, and in cultivating tenants can use appropriate agricultural practices (conceal bushes, warm soil and air, and even crops in protective ground, in greenhouses. Characteristically, technology of greenhouses growers is even used in Kherson region. These data can be used in neighborhood and the adjacent areas, especially they are useful for the practice of growing grapes. The possibility of successful cultivation of dozens of grape varieties in the North-Eastern steppe land of Ukraine has been well-grounded.

  12. Influence of Absorption of Thermal Radiation in the Surface Water Film on the Characteristics and Ignition Conditions

    Directory of Open Access Journals (Sweden)

    Syrodoy Samen V.

    2016-01-01

    Full Text Available The results of the mathematical modeling of homogeneous particle ignition process of coal-water fuel covered with water film have been presented in article. The set co-occurring physical (inert heating, evaporation of water film and thermochemical (thermal degradation, inflammation process have been considered. Heat inside the film has been considered as the model of radiation-conductive heat transfer. Delay times have been determined according to the results of numerical modeling of the ignition. It has been shown that the water film can have a significant impact on performance and the ignition conditions. It has been found that heating main fuel layer occurs in the process of evaporation of water film. For this reason, the next (after the evaporation of the water film thermal preparation (coal heating, thermal decomposition of the organic part of the fuel and inflammation occur faster.

  13. Unsteady Casson nanofluid flow over a stretching sheet with thermal radiation, convective and slip boundary conditions

    Directory of Open Access Journals (Sweden)

    Ibukun Sarah Oyelakin

    2016-06-01

    Full Text Available In this paper we report on combined Dufour and Soret effects on the heat and mass transfer in a Casson nanofluid flow over an unsteady stretching sheet with thermal radiation and heat generation. The effects of partial slip on the velocity at the boundary, convective thermal boundary condition, Brownian and thermophoresis diffusion coefficients on the concentration boundary condition are investigated. The model equations are solved using the spectral relaxation method. The results indicate that the fluid flow, temperature and concentration profiles are significantly influenced by the fluid unsteadiness, the Casson parameter, magnetic parameter and the velocity slip. The effect of increasing the Casson parameter is to suppress the velocity and temperature growth. An increase in the Dufour parameter reduces the flow temperature, while an increase in the value of the Soret parameter causes increase in the concentration of the fluid. Again, increasing the velocity slip parameter reduces the velocity profile whereas increasing the heat generation parameter increases the temperature profile. A validation of the work is presented by comparing the current results with existing literature.

  14. Experimental research on thermal comfort in the university classroom of regular semesters in Korea

    International Nuclear Information System (INIS)

    Jung, Gun Joo; Oh, Geun Sug; Im, Young Bin; Song, Sung Ki; Ahn, Young Chull

    2011-01-01

    This research has investigated physical variables affecting indoor thermal comfort and subjective responses of thermal comfort of students in a university in Korea in which the weather is oceanic temperate climate, and has been performed to contribute to the research fields of Sustainable Thermal Standard and Adaptive Thermal Comfort (ATC). This research is based on the ISO 7730-2005 standard and the ATC theories and 4 main variables of PMV such as dry bulb temperature (Ta), relative humidity (RH), black bulb temperature (Tg), and air velocity (Va) are measured once a week during two regular semesters. A clothing insulation, a thermal sensation vote (TSV), an acceptability of thermal environment, and a preference for cooling and heating are investigated at the same time using a questionnaire. This study was carried out for 26 weeks during the spring season, from March to June 2009, and the autumn season, from September to December 2009. The main achievements of this study are as follows. Monthly Mean Outdoor Temperature (MMOT) and Operative Temperature (OT) in the classroom during research periods are 7.4∼23.3 .deg. C and 17.5∼29.0 .deg. C, respectively. The acceptability ratio of thermal environment shows over 80% when the range of OT in the classroom is 17∼25 .deg. C, and the range can be applicable to operative index of heating and cooling of classroom. The mean TSV of respondents is almost 'neutral (0)' when the PMV in the classroom moves to 'neutral (0)' and 'slightly cool (-1)', and the TSV is almost '+1.5' when the PMV moves to 'slightly warm (+1)'. The acceptability ratio of thermal environment is slightly different from ASHRAE Standard 55-2004. So it is necessary to more investigate standard range of acceptability of thermal environment in oceanic temperate climate region using much more databases

  15. Thermal Testing Methods for Solar Dryers

    DEFF Research Database (Denmark)

    Singh, Shobhana

    2017-01-01

    Solar food drying is a complex heat and mass transfer phenomena which depend on a number of drying process-dependent parameters such as operating conditions and characteristics of the food product to be dried. The variation in these parameters significantly affects the overall performance...... of the dryer system. Since commercial growth and acceptance of any solar dryer system momentously depend on its performance guarantee, the development of a standard methodology for their thermal testing has become necessary. The standard testing method not only provides better performance management...... of the dryer system but allows the manufacturers to achieve competitive efficiency and good product quality by comparing the available designs. In this chapter, an extensive review of solar dryer performance evaluation has been carried out. Furthermore, the chapter describes the existing testing procedures...

  16. Thermal hydraulic conditions inducing incipient cracking in the 900 MWe unit 93 D reactor coolant pump shafts; Pompes primaires 93 D des tranches de 900 MW. Conditions thermo-hydrauliques d`amorcage des fissures d`arbres

    Energy Technology Data Exchange (ETDEWEB)

    Bore, C.

    1995-12-31

    From 1987, 900 MWe plant operating feedback revealed cracking in the lower part of the reactor coolant pump shafts, beneath the thermal ring. Metallurgical examinations established that this was due to a thermal fatigue phenomenon known as thermal crazing, occurring after a large number of cycles. Analysis of thermal hydraulic conditions initiating the cracks does not allow exact quantification of the thermal load inducing cracking. Only qualitative analyses are thus possible, the first of which, undertaken by the pump manufacturer, Jeumont Industrie, showed that the cracks could not be due to the major transients (stop-start, injection cut-off), which were too few in number. Another explanation was then put forward: the thermal ring, shrunk onto the shaft it is required to protect against thermal shocks, loosens to allow an alternating downflow of cold water from the shaft seals and an upflow of hot water from the primary system. However, approximate calculations showed that the flow involved would be too slight to initiate the cracking observed. A more stringent analysis undertaken with the 2D flow analysis code MELODIE subsequently refuted the possibility of alternating flows beneath the ring establishing that only a hot water upflow occurred due to a `viscosity pump` phenomenon. Crack initiation was finally considered to be due to flowrate variations beneath the ring, with the associated temperature fluctuations. This flowrate fluctuation could be due to an unidentified transient phenomenon or to a variation in pump operating conditions. This analysis of the hydraulic conditions initiating the cracks disregards shaft surface residual stresses. These are tensile stresses and show that loads less penalizing than those initially retained could cause incipient cracking. Thermal ring modifications to reduce these risks were proposed and implemented. In addition, final metallurgical treatment of the shafts was altered and implemented. (Abstract Truncated)

  17. Thermal Comfort in Simulated Office Environment with Four Convective and Radiant Cooling Systems

    DEFF Research Database (Denmark)

    Bolashikov, Zhecho Dimitrov; Mustakallio, Panu; Kolencíková, Sona

    2013-01-01

    with overhead mixing ventilation (MVRC). Whole body thermal sensation (TS) and whole body TS acceptability under the four systems in a simulated office room for one hour exposure were collected. The simulated two-man office (4.12 x 4.20 x 2.89 m, L x W x H) was kept at 26 oC room air temperature. Moderate heat...... to “neutral” compared to male, whose votes were closer to the “slightly warm” thermal sensation. The whole body TS acceptability was rated close to ''clearly acceptable'' (EN 15251-2007) and was independent of subject's gender for all tested systems....

  18. Thermal and economical optimization of air conditioning units with vapor compression refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Sanaye, S.; Malekmohammadi, H.R. [Iran University of Science and Technology, Tehran (Iran). Dept. of Mechanical Engineering

    2004-09-01

    A new method of thermal and economical optimum design of air conditioning units with vapor compression refrigeration system, is presented. Such a system includes compressor, condenser, evaporator, centrifugal and axial fans. Evaporator and condenser temperatures, their heating surface areas (frontal surface area and number of tubes), centrifugal and axial fan powers, and compressor power are among the design variables. The data provided by manufacturers for fan (volume flow rate versus pressure drop) and compressor power (using evaporator and condenser temperatures) was used to choose these components directly from available data for consumers. To study the performance of the system under various situations, and implementing the optimization procedure, a simulation program including all thermal and geometrical parameters was developed. The objective function for optimization was the total cost per unit cooling load of the system including capital investment for components as well as the required electricity cost. To find the system design parameters, this objective function was minimized by Lagrange multipliers method. The effects of changing the cooling load on optimal design parameters were studied. (author)

  19. OPTIMIZATION OF ETHANOL CONCENTRATION, GLYCEROL CONCENTRATION AND TEMPERATURE CONDITIONS OF GRAPE-MAHUA WINE TO MAXIMIZE THE QUALITY AND OVERALL ACCEPTABILITY

    Directory of Open Access Journals (Sweden)

    Mandeep Kaur

    2013-06-01

    Full Text Available Black grapes (Vitis vinifera and mahua (Madhuca longfolia extract was used in 90:10 grape-mahua ratio for fermentation for 15 days and subjected to clarification using bentonite and gelatin as fining agents. Ageing was allowed for three months and studies were conducted using response surface methodology to assess the effect of ethanol, glycerol and temperature on viscosity, color, specific gravity, pH and overall acceptability. Experimental designs were conducted and 20 samples were prepared containing varying concentration of ethanol (7.55%-13.44%, glycerol (6.19-18.8g/l and temperature (5.6-22.4oC respectively. The maximum desirability of 93% was obtained for wine under the optimized conditions 13.44% ethanol, 6.19g/l glycerol and 14oC temperature, having viscosity (efflux time, 12.9 s; color absorbance, 4.61; SG, 1.0012; pH, 3.34 and overall acceptability, 8.47.

  20. Acceptance criteria for the ITER divertor vertical target

    International Nuclear Information System (INIS)

    Fouquet, S.; Schlosser, J.; Merola, M.; Durocher, A.; Escourbiac, F.; Grosman, A.; Missirlian, M.; Portafaix, C.

    2006-01-01

    In the frame of the toroidal pump limiter fabrication for Tore Supra, CEA developed a large experience of infrared test for acceptance of high heat flux components armoured with carbon fibre composite flat tiles. The test is based on a thermal transient induced by an alternative hot/cold water flow in the heat sink structure. The tile surface temperature transients are compared with those of a reference element, the maximum difference for each tile leading to a value called ΔT ref m ax . This method is proposed for the commissioning of plasma facing components for the ITER divertor vertical target. This paper describes the determination of the best acceptance criteria for the 'monoblock' geometry of the carbon part. First, it has been shown that the location and the extension of the defects could reliably be determined by monitoring both top and lateral surfaces during the test. Second, it was possible to fix an acceptance method based on ΔT ref m ax . Samples with calibrated defects are now under fabrication to validate the results

  1. Student acceptance of e-books: A case study of landmark university ...

    African Journals Online (AJOL)

    Student acceptance of e-books was tested using UTAUT model. Performance expectancy Effort expectancy and Facilitating conditions were seen to significantly influence the acceptance of e-books by students in Landmark University, while Social Influence did not influence acceptance of e-books. Key Words: E-books, ...

  2. Development of a 30-cm ion thruster thermal-vacuum power processor

    Science.gov (United States)

    Herron, B. G.

    1976-01-01

    The 30-cm Hg electron-bombardment ion thruster presently under development has reached engineering model status and is generally accepted as the prime propulsion thruster module to be used on the earliest solar electric propulsion missions. This paper presents the results of a related program to develop a transistorized 3-kW Thermal-Vacuum Breadboard (TVBB) Power Processor for this thruster. Emphasized in the paper are the implemented electrical and mechanical designs as well as the resultant system performance achieved over a range of test conditions. In addition, design modifications affording improved performance are identified and discussed.

  3. Thermal modeling of core sampling in flammable gas waste tanks. Part 2: Rotary-mode sampling

    International Nuclear Information System (INIS)

    Unal, C.; Poston, D.; Pasamehmetoglu, K.O.; Witwer, K.S.

    1997-01-01

    The radioactive waste stored in underground storage tanks at Hanford site includes mixtures of sodium nitrate and sodium nitrite with organic compounds. The waste can produce undesired violent exothermic reactions when heated locally during the rotary-mode sampling. Experiments are performed varying the downward force at a maximum rotational speed of 55 rpm and minimum nitrogen purge flow of 30 scfm. The rotary drill bit teeth-face temperatures are measured. The waste is simulated with a low thermal conductivity hard material, pumice blocks. A torque meter is used to determine the energy provided to the drill string. The exhaust air-chip temperature as well as drill string and drill bit temperatures and other key operating parameters were recorded. A two-dimensional thermal model is developed. The safe operating conditions were determined for normal operating conditions. A downward force of 750 at 55 rpm and 30 scfm nitrogen purge flow was found to yield acceptable substrate temperatures. The model predicted experimental results reasonably well. Therefore, it could be used to simulate abnormal conditions to develop procedures for safe operations

  4. A novel human body exergy consumption formula to determine indoor thermal conditions for optimal human performance in office buildings

    DEFF Research Database (Denmark)

    Wu, Xiaozhou; Zhao, Jianing; Olesen, Bjarne W.

    2013-01-01

    In this paper, a novel human body exergy consumption formula was derived strictly according to Gagge's two-node thermal transfer model. The human body exergy consumption calculated by the formula was compared with values calculated using Shukuya's formula for a typical office environment....... The results show that human body exergy consumption calculated by either of these formulas reaches a minimum under the same thermal condition. It is shown that this is in accordance with expectation. The relation between human performance and human body exergy consumption was studied by analyzing the data...... obtained in simulated office environments in winter. The results show that human body exergy consumption and human performance are inversely as operative temperature changes from 17 to 28°C or human thermal sensation changes from −1.0 to +1.4, and that optimum thermal comfort cannot be expected to lead...

  5. Effect of the combined stress on the life of components under thermal cycling conditions

    International Nuclear Information System (INIS)

    Zuchowski, R.; Zietkowski, L.

    1987-01-01

    The life of structural components subjected to temperature changes is affected, among other factors, by the nature of the stress field. If life prediction for axially stressed components can be accomplished with a number of well established techniques, the behaviour under a complex state of stress and varying temperature conditions still is the object of intensive research. The present study was aimed at assessing the influence of the stress field upon the life of specimens made of chromium-nickel H23N18 steel under thermal cycling conditions. The designation of steel is in accordance with Polish Standards. The experiments were made on thin-walled tubular specimens loaded with various combinations of a static axial force and a static torque. (orig./GL)

  6. Assessment of the thermal environment in an aircraft cabin

    DEFF Research Database (Denmark)

    Ingers, S.; Melikov, Arsen Krikor

    2004-01-01

    equivalent temperature, up to 5.8°C, was identified in the outer seats. The results reveal that in an aircraft cabin, passengers in the outer seats may be exposed to thermal asymmetry and draught and may not find the thermal environment acceptable if the ventilation air is not properly supplied....

  7. Online optimal control of variable refrigerant flow and variable air volume combined air conditioning system for energy saving

    International Nuclear Information System (INIS)

    Zhu, Yonghua; Jin, Xinqiao; Du, Zhimin; Fang, Xing

    2015-01-01

    The variable refrigerant flow (VRF) and variable air volume (VAV) combined air conditioning system can solve the problem of the VRF system in outdoor air ventilation while taking advantage of its high part load energy efficiency. Energy performance of the combined air conditioning system can also be optimized by joint control of both the VRF and the VAV parts. A model-based online optimal control strategy for the combined air conditioning system is presented. Simplified adaptive models of major components of the combined air conditioning system are firstly developed for predicting system performances. And a cost function in terms of energy consumption and thermal comfort is constructed. Genetic algorithm is used to search for the optimal control sets. The optimal control strategy is tested and evaluated through two case studies based on the simulation platform. Results show that the optimal strategy can effectively reduce energy consumption of the combined air conditioning system while maintaining acceptable thermal comfort. - Highlights: • A VRF and VAV combined system is proposed. • A model-based online optimal control strategy is proposed for the combined system. • The strategy can reduce energy consumption without sacrificing thermal comfort. • Novel simplified adaptive models are firstly developed for the VRF system

  8. Thermal electron mobilities in low density gaseous mixtures

    International Nuclear Information System (INIS)

    Dmitriev, O.W.; Tchorzewska, W.; Szamrej, I.; Forys, M.

    1992-01-01

    A new method of obtaining thermal electron mobilities from experimental dependencies observed in the electron swarm is described; the method is suitable for both electron accepting and non-accepting systems. The electron mobilities for CO 2 , CH 4 C 2 H 6 as well as for N 2 , Ar, Xe, Kr and their mixtures with carbon dioxide are obtained. (Author)

  9. Thermal and physiochemical properties of pellets with power aims made of sawmill residual product

    International Nuclear Information System (INIS)

    Casanova Treto, Pedro; Solis, Kattia; Carrillo, Tonny

    2017-01-01

    Sawmill residual product of Pylon (Hyeronima alchorneoides) and Eucalyptus (Eucalyptus spp) species was used to produce pellets under different conditions of densification. Experimental equipment was used to determine the thermal conductivity, thermal diffusivity and specific heat. Physicochemical properties of the pellets obtained under different conditions of densification, such as ash content and calorific value were determined. The content of nitrogen, chlorine and sulfur present in the material used to produce the pellets was estimated. Thermal conductivity values were determined between 0,253 W/m·K and 0,279 W/m·K; 1,748 m2 /s and 2,314 m2 /s for the thermal diffusivity, and in the case of specific heat were determined values between 3,019 kJ/kg·K and 2,183 kJ/kg·K. The high heat values was between 18 907 kJ/kg and 18 960 kJ/kg. An ash content of 1,31% was determined on a dry basis. Finally, the content of nitrogen, chlorine and sulfur determined in the residual biomass used, corresponds to 0,1129%, 0,0592 % and 0,0317%, respectively. A direct relationship between increasing the bulk density of the pellets and the thermal properties was determined. The calorific value and the ash content had a negligible effect due to the treatments applied. The estimated content of N, Cl and S corresponds to that expected in the selected biomass. Comparison of the properties of the pellets produced under the conditions studied -densification, against regulations-, showed acceptable results, entering these in terms of different categories of quality. (author) [es

  10. Analysis of Reactor Pressurized Thermal Shock Conditions Considering Upgrading of Systems Important to Safety

    International Nuclear Information System (INIS)

    Mazurok, A.S; Vyshemirskyij, M.P.

    2015-01-01

    The paper analyzes conditions of pressurized thermal shock on the reactor pressure vessel taking into account upgrading of the emergency core cooling system and primary overpressure protection system. For representative accident scenarios, calculation and comparative analysis was carried out. These scenarios include a small leak from the hot leg and PRZ SV stuck opening with re closure after 3600 sec and 3 SG heat transfer tube rupture. The efficiency of mass flow control by valves on the pump head (emergency core cooling systems) and cold overpressure protection (primary overpressure protection system) was analyzed. The thermal hydraulic model for RELAP5/Mod3.2 code with detailed downcomer (DC) model and changes in accordance with upgrades was used for calculations. Detailed (realistic) modeling of piping and equipment was performed. The upgrades prevent excessive primary cooling and, consequently, help to preserve the RPV integrity and to avoid the formation of a through crack, which can lead to a severe accident

  11. Pathways of the Maillard reaction under physiological conditions.

    Science.gov (United States)

    Henning, Christian; Glomb, Marcus A

    2016-08-01

    Initially investigated as a color formation process in thermally treated foods, nowadays, the relevance of the Maillard reaction in vivo is generally accepted. Many chronic and age-related diseases such as diabetes, uremia, atherosclerosis, cataractogenesis and Alzheimer's disease are associated with Maillard derived advanced glycation endproducts (AGEs) and α-dicarbonyl compounds as their most important precursors in terms of reactivity and abundance. However, the situation in vivo is very challenging, because Maillard chemistry is paralleled by enzymatic reactions which can lead to both, increases and decreases in certain AGEs. In addition, mechanistic findings established under the harsh conditions of food processing might not be valid under physiological conditions. The present review critically discusses the relevant α-dicarbonyl compounds as central intermediates of AGE formation in vivo with a special focus on fragmentation pathways leading to formation of amide-AGEs.

  12. Thermal modeling of nickel-hydrogen battery cells operating under transient orbital conditions

    Science.gov (United States)

    Schrage, Dean S.

    1991-01-01

    An analytical study of the thermal operating characteristics of nickel-hydrogen battery cells is presented. Combined finite-element and finite-difference techniques are employed to arrive at a computationally efficient composite thermal model representing a series-cell arrangement operating in conjunction with a radiately coupled baseplate and coldplate thermal bus. An aggressive, low-mass design approach indicates that thermal considerations can and should direct the design of the thermal bus arrangement. Special consideration is given to the potential for mixed conductive and convective processes across the hydrogen gap. Results of a compressible flow model are presented and indicate the transfer process is suitably represented by molecular conduction. A high-fidelity thermal model of the cell stack (and related components) indicates the presence of axial and radial temperature gradients. A detailed model of the thermal bus reveals the thermal interaction of individual cells and is imperative for assessing the intercell temperature gradients.

  13. Application of uncertainty analysis method for calculations of accident conditions for RP AES-2006

    International Nuclear Information System (INIS)

    Zajtsev, S.I.; Bykov, M.A.; Zakutaev, M.O.; Siryapin, V.N.; Petkevich, I.G.; Siryapin, N.V.; Borisov, S.L.; Kozlachkov, A.N.

    2015-01-01

    An analysis of some accidents using the uncertainly assessment methods is given. The list of the variable parameters incorporated the model parameters of the computer codes, initial and boundary conditions of reactor plant, neutronics. On the basis of the performed calculations of the accident conditions using the statistical method, errors assessment is presented in the determination of the main parameters comparable with the acceptance criteria. It was shown that in the investigated accidents the values of the calculated parameters with account for their error obtained from TRAP-KS and KORSAR/GP Codes do not exceed the established acceptance criteria. Besides, these values do not exceed the values obtained in the conservative calculations. A possibility in principle of the actual application of the method of estimation of uncertainty was shown to justify the safety of WWER AES-2006 using the thermal-physical codes KORSAR/GP and TRAP-KS, PANDA and SUSA programs [ru

  14. Thermal performance of marketed SDHW systems under laboratory conditions

    DEFF Research Database (Denmark)

    Furbo, Simon; Andersen, Elsa; Fan, Jianhua

    A test facility for solar domestic hot water systems, SDHW systems was established at the Technical University of Denmark in 1992. During the period 1992-2012 21 marketed SDHW systems, 16 systems from Danish manufacturers and 5 systems from manufacturers from abroad, have been tested in the test...... comfort, avoiding simple errors, using the low flow principle and heat stores with a high degree of thermal stratification and by using components with good thermal characteristics....

  15. A comparison between the IAEA Safety Series 6 thermal environment and a proposed alternative thermal environment

    International Nuclear Information System (INIS)

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

    1994-01-01

    The present regulations for packaging and transportation of radioactive materials, IAEA Safety Series No. 6; 1985, establish specific criteria for the thermal environment of a hypothetical accident. The regulation states: The scope of this paper is to examine the effects on modeling that result with the Fry proposed thermal boundary conditions. The examination is accomplished by comparing thermal model results using the current IAEA specified thermal environment and the Fry proposed thermal boundary conditions

  16. Protection against cold in prehospital care-thermal insulation properties of blankets and rescue bags in different wind conditions.

    Science.gov (United States)

    Henriksson, Otto; Lundgren, J Peter; Kuklane, Kalev; Holmér, Ingvar; Bjornstig, Ulf

    2009-01-01

    In a cold, wet, or windy environment, cold exposure can be considerable for an injured or ill person. The subsequent autonomous stress response initially will increase circulatory and respiratory demands, and as body core temperature declines, the patient's condition might deteriorate. Therefore, the application of adequate insulation to reduce cold exposure and prevent body core cooling is an important part of prehospital primary care, but recommendations for what should be used in the field mostly depend on tradition and experience, not on scientific evidence. The objective of this study was to evaluate the thermal insulation properties in different wind conditions of 12 different blankets and rescue bags commonly used by prehospital rescue and ambulance services. The thermal manikin and the selected insulation ensembles were setup inside a climatic chamber in accordance to the modified European Standard for assessing requirements of sleeping bags. Fans were adjusted to provide low (value, Itr (m2 C/Wclo; where C = degrees Celcius, and W = watts), was calculated from ambient air temperature (C), manikin surface temperature (C), and heat flux (W/m2). In the low wind condition, thermal insulation of the evaluated ensembles correlated to thickness of the ensembles, ranging from 2.0 to 6.0 clo (1 clo = 0.155 m2 C/W), except for the reflective metallic foil blankets that had higher values than expected. In moderate and high wind conditions, thermal insulation was best preserved for ensembles that were windproof and resistant to the compressive effect of the wind, with insulation reductions down to about 60-80% of the original insulation capacity, whereas wind permeable and/or lighter materials were reduced down to about 30-50% of original insulation capacity. The evaluated insulation ensembles might all be used for prehospital protection against cold, either as single blankets or in multiple layer combinations, depending on ambient temperatures. However, with extended

  17. Measurement of thermal transmittance of opaque facade wall relationship with meteorological conditions

    Directory of Open Access Journals (Sweden)

    Antunović Biljana S.

    2015-01-01

    Full Text Available This paper presents the results of measurements of thermal transmittance or as otherwise called U-value [W/m2⋅K] of opaque facade wall of preschool institution built in 1977. The building has an incomplete technical documentation according to which considered wall was built of brick and masonry mortar. Thermal characteristics of the incorporated materials have not been specified. Considering that in the period of building construction JUS standards was used, a possible range of calculated U-vales was obtained (1,241-1,404 W/m2·K. Measurements were performed in accordance with ISO 9869 during three time periods with the resulting U-values (1,269±0,276 W/m2·K; 1,025±0,175 W/m2·K; 1,200±0,212 W/m2·K that do not differ from each other within experimental uncertainty. Furthermore, the correlation of the measured U-values and meteorological conditions that prevailed during the measurements was analyzed. In the second measurement period, the average values of the total cloud cover and low cloud cover were less, and the average duration of sunshine was longer than in the other two measurement periods.

  18. Efficacy of Thermally Conditioned Sisal FRP Composite on the Shear Characteristics of Reinforced Concrete Beams

    Directory of Open Access Journals (Sweden)

    Tara Sen

    2013-01-01

    Full Text Available The development of commercially viable composites based on natural resources for a wide range of applications is on the rise. Efforts include new methods of production and the utilization of natural reinforcements to make biodegradable composites with lignocellulosic fibers, for various engineering applications. In this work, thermal conditioning of woven sisal fibre was carried out, followed by the development of woven sisal fibre reinforced polymer composite system, and its tensile and flexural behaviour was characterized. It was observed that thermal conditioning improved the tensile strength and the flexural strength of the woven sisal fibre composites, which were observed to bear superior values than those in the untreated ones. Then, the efficacy of woven sisal fibre reinforced polymer composite for shear strengthening of reinforced concrete beams was evaluated using two types of techniques: full and strip wrapping techniques. Detailed analysis of the load deflection behaviour and fracture study of reinforced concrete beams strengthened with woven sisal under shearing load were carried out, and it was concluded that woven sisal FRP strengthened beams, underwent very ductile nature of failure, without any delamination or debonding of sisal FRP, and also increased the shear strength and the first crack load of the reinforced concrete beams.

  19. Quantum thermal rectification to design thermal diodes and transistors

    Energy Technology Data Exchange (ETDEWEB)

    Joulain, Karl; Ezzahri, Younes; Ordonez-Miranda, Jose [Univ. de Poitiers, Futuroscope Chasseneuil (France). Inst. Pprime, CNRS

    2017-05-01

    We study in this article how heat can be exchanged between two-level systems, each of them being coupled to a thermal reservoir. Calculations are performed solving a master equation for the density matrix using the Born-Markov approximation. We analyse the conditions for which a thermal diode and a thermal transistor can be obtained as well as their optimisation.

  20. Thermal comfort

    CSIR Research Space (South Africa)

    Osburn, L

    2010-01-01

    Full Text Available Thermal comfort is influenced by environmental parameters as well as other influences including asymmetric heating and cooling conditions. Additionally, some aspects of thermal comfort may be exploited so as to enable a building to operate within a...

  1. Human thermal physiological and psychological responses under different heating environments.

    Science.gov (United States)

    Wang, Zhaojun; Ning, Haoran; Ji, Yuchen; Hou, Juan; He, Yanan

    2015-08-01

    Anecdotal evidence suggests that many residents of severely cold areas of China who use floor heating (FH) systems feel warmer but drier compared to those using radiant heating (RH) systems. However, this phenomenon has not been verified experimentally. In order to validate the empirical hypothesis, and research the differences of human physiological and psychological responses in these two asymmetrical heating environments, an experiment was designed to mimic FH and RH systems. The subjects participating in the experiment were volunteer college-students. During the experiment, the indoor air temperature, air speed, relative humidity, globe temperature, and inner surface temperatures were measured, and subjects' heart rate, blood pressure and skin temperatures were recorded. The subjects were required to fill in questionnaires about their thermal responses during testing. The results showed that the subjects' skin temperatures, heart rate and blood pressure were significantly affected by the type of heating environment. Ankle temperature had greatest impact on overall thermal comfort relative to other body parts, and a slightly cool FH condition was the most pleasurable environment for sedentary subjects. The overall thermal sensation, comfort and acceptability of FH were higher than that of RH. However, the subjects of FH felt drier than that of RH, although the relative humidity in FH environments was higher than that of the RH environment. In future environmental design, the thermal comfort of the ankles should be scrutinized, and a FH cool condition is recommended as the most comfortable thermal environment for office workers. Consequently, large amounts of heating energy could be saved in this area in the winter. The results of this study may lead to more efficient energy use for office or home heating systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Nevada Test Site Waste Acceptance Criteria

    International Nuclear Information System (INIS)

    U.S. Department of Energy, Nevada Operations Office, Waste Acceptance Criteria

    1999-01-01

    This document provides the requirements, terms, and conditions under which the Nevada Test Site will accept low-level radioactive and mixed waste for disposal; and transuranic and transuranic mixed waste for interim storage at the Nevada Test Site

  3. Nevada Test Site Waste Acceptance Criteria

    International Nuclear Information System (INIS)

    U. S. Department of Energy, National Nuclear Security Administration Nevada Site Office

    2005-01-01

    This document establishes the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) waste acceptance criteria (WAC). The WAC provides the requirements, terms, and conditions under which the Nevada Test Site (NTS) will accept low-level radioactive (LLW) and mixed waste (MW) for disposal. It includes requirements for the generator waste certification program, characterization, traceability, waste form, packaging, and transfer. The criteria apply to radioactive waste received at the NTS Area 3 and Area 5 Radioactive Waste Management Complex (RWMC) for storage or disposal

  4. Reduce, reuse, recycle: Acceptance of CO_2-utilization for plastic products

    International Nuclear Information System (INIS)

    Heek, Julia van; Arning, Katrin; Ziefle, Martina

    2017-01-01

    Global warming is a central threat for today's society caused by greenhouse gas emissions, mostly carbon dioxide emissions. Carbon dioxide capture and utilization (CCU) is a promising approach to reduce emissions and the use of expensive and limited fossil resources. Applying CCU, carbon dioxide (CO_2) can be incorporated as raw material during the manufacture of plastic products. While most of the studies address technical feasibilities, hardly any systematic research on public perception and acceptance of those specific products exists so far. This study empirically investigates the acceptance of CCU plastic products (mattress as example). First, interviews with experts and lay people revealed critical acceptance factors (CO_2 proportion, saving of fossil resources, disposal conditions, perceived health complaints). Their relative importance was detailed in two consecutive conjoint studies. Study 1 revealed disposal conditions and saving of fossil resources as essential for product selection, while the products’ CO_2 proportion was less important. In study 2, potential health complaints were integrated as well as individual levels of domain knowledge and risk perception, which significantly affected acceptance of CCU products. Recommendations concerning communication strategies for policy and industry were derived. - Highlights: • Study provides insights into the acceptance of specific CCU products. • Disposal conditions and savings of fossil resource are main drivers of acceptance. • Concerns about potential health effects act as major barrier especially for laypeople. • Perceived knowledge and risk perception affect CCU product acceptance. • Communication strategy recommendations for policy and industry are derived.

  5. Thermal perceptions, general adaptation methods and occupant's idea about the trade-off between thermal comfort and energy saving in hot-humid regions

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ruey-Lung [Department of Occupational Safety and Health, China Medical University, 91 Huseh-Shin Road, Taichung 404 (China); Cheng, Ming-Jen [Department of Architecture, Feng Chia University, 100 Wen-Hwa Road, Seatwen, Taichung 407 (China); Lin, Tzu-Ping [Department of Leisure Planning, National Formosa University, 64 Wen-Hua Road, Huwei, Yunlin 632 (China); Ho, Ming-Chin [Architecture and Building Research Institute, Ministry of the Interior, 13F, No. 200, Sec. 3, Bei-sin Road, Sindian City, Taipei County 231 (China)

    2009-06-15

    A field study conducted in workplaces and residences in Taiwan is carried out to clarify two questions in detail: (1) do people in the tropical climate regions demonstrate a correlation between thermal sensation and thermal dissatisfaction the same as the PMV-PPD formula in the ISO 7730; and (2) does the difference in opportunities to choose from a variety of methods to achieve thermal comfort affects thermal perceptions of occupants? A new predicted formula of percentage of dissatisfied (PD) relating to mean thermal sensation votes (TSVs) is proposed for hot and humid regions. Besides an increase in minimum rate of dissatisfied from 5% to 9%, a shift of the TSV with minimum PD to the cool side of sensation scale is suggested by the new proposed formula. It also reveals that the limits of TSV corresponding to 80% acceptability for hot and humid regions are -1.45 and +0.65 rather than -0.85 and +0.85 suggested by ISO 7730. It is revealed in the findings that the effectiveness, availability and cost of a thermal adaptation method can affect the interviewees' thermal adaptation behaviour. According to the discussion of interviewees' idea about the trade-off between thermal comfort and energy saving, it is found that an energy-saving approach at the cost of sacrificing occupant's thermal comfort is difficult to set into action, but those ensure the occupant's comfort are more acceptable and can be easily popularized. (author)

  6. Monitoring results and analysis of thermal comfort conditions in experimental buildings for different heating systems and ventilation regimes during heating and cooling seasons

    Science.gov (United States)

    Gendelis, S.; Jakovičs, A.; Ratnieks, J.; Bandeniece, L.

    2017-10-01

    This paper focuses on the long-term monitoring of thermal comfort and discomfort parameters in five small test buildings equipped with different heating and cooling systems. Calculations of predicted percentage of dissatisfied people (PPD) index and discomfort factors are provided for the room in winter season running three different heating systems - electric heater, air-air heat pump and air-water heat pump, as well as for the summer cooling with split type air conditioning systems. It is shown that the type of heating/cooling system and its working regime has an important impact on thermal comfort conditions in observed room. Recommendations for the optimal operating regimes and choice of the heating system from the thermal comfort point of view are summarized.

  7. Efficacy of Thermally Conditioned Sisal FRP Composite on the Shear Characteristics of Reinforced Concrete Beams

    OpenAIRE

    Sen, Tara; Reddy, H. N. Jagannatha

    2013-01-01

    The development of commercially viable composites based on natural resources for a wide range of applications is on the rise. Efforts include new methods of production and the utilization of natural reinforcements to make biodegradable composites with lignocellulosic fibers, for various engineering applications. In this work, thermal conditioning of woven sisal fibre was carried out, followed by the development of woven sisal fibre reinforced polymer composite system, and its tensile and flex...

  8. Development of Waste Acceptance Criteria at 221-U Building: Initial Flow and Transport Scoping Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Freedman, Vicky L.; Zhang, Z. F.; Keller, Jason M.; Chen, Yousu

    2007-05-30

    This report documents numerical flow and transport simulations performed that establish initial waste acceptance criteria for the potential waste streams that may be safely sequestered in the 221-U Building and similar canyon structures. Specifically, simulations were executed to identify the maximum loading of contaminant mass (without respect to volume) that can be emplaced within the 221-U Building with no more than 1 pCi/m2 of contaminant migrating outside the structure within a 1,000 year time period. The initial scoping simulations were executed in one dimension to assess important processes, and then two dimensions to establish waste acceptance criteria. Two monolithic conditions were assessed: (1) a grouted canyon monolith; and (2) a canyon monolith filled with sand, both assuming no cracks or fissures were present to cause preferential transport. A three-staged approach was taken to account for different processes that may impact the amount of contaminant that can be safely sequestered in canyon structure. In the first stage, flow and transport simulations established waste acceptance criteria based on a linear (Kd) isotherm approach. In the second stage, impacts on thermal loading were examined and the differences in waste acceptance criteria quantified. In the third stage of modeling, precipitation/dissolution reactions were considered on the release and transport of the contaminants, and the subsequent impact on the maximum contaminant loading. The reactive transport modeling is considered a demonstration of the reactive transport capability, and shows the importance of its use for future performance predictions once site-specific data have been obtained.

  9. Thermal Radiation Effects on Thermal Explosion in Polydisperse Fuel Spray-Probabilistic Model

    Directory of Open Access Journals (Sweden)

    Ophir Navea

    2011-06-01

    Full Text Available We investigate the effect of thermal radiation on the dynamics of a thermal explosion of polydisperse fuel spray with a complete description of the chemistry via a single-step two-reactant model of general order. The polydisperse spray is modeled using a Probability Density Function (PDF. The thermal radiation energy exchange between the evaporation surface of the fuel droplets and the burning gas is described using the Marshak boundary conditions. An explicit expression of the critical condition for thermal explosion limit is derived analytically and represents a generalization of the critical parameter of the classical Semenov theory. Because we investigated the model in the range where the temperature is very high, the effect of the thermal radiation is significant.

  10. A comparison of the CHF between tubes and annuli under PWR thermal-hydraulic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Herer, C. [RRAMATOME EP/TC, Paris (France); Souyri, A. [EdF DER/RNE/TTA, Chatou (France); Garnier, J. [CEA DRN/DTP/STR/LETC, Grenoble (France)

    1995-09-01

    Critical Heat Flux (CHF) tests were carried out in three tubes with inside diameters of 8, 13, and 19.2 mm and in two annuli with an inner tube of 9.5 mm and an outer tube of 13 or 19.2 mm. All axial heat flux distributions in the test sections were uniform. The coolant fluid was Refrigerant 12 (Freon-12) under PWR thermal-hydraulic conditions (equivalent water conditions - Pressure: 7 to 20 MPa, Mass Velocity: 1000 to 6000 kg/m2/s, Local Quality: -75% to +45%). The effect of tube diameter is correlated for qualities under 15%. The change from the tube to the annulus configuration is correctly taken into account by the equivalent hydraulic diameter. Useful information is also provided concerning the effect of a cold wall in an annulus.

  11. Thermal Assessment of Low-Cost Rural Housing—A Case Study in the Ecuadorian Andes

    Directory of Open Access Journals (Sweden)

    Isabel Miño-Rodríguez

    2016-09-01

    Full Text Available The aim of this research is to assess the indoor thermal performance of rural dwellings in the Ecuadorian highlands through both experimental and numerical analysis. A three-step methodology was applied to conduct the research: (a field data collection, (b building thermal model development and calibration, and (c comparison analysis and assessment of traditional improvement strategies. Qualitative and quantitative data were collected from two representative rural dwellings under typical usage conditions. The first is a traditional construction, medium-exposed thermal mass dwelling (Case A. The second is a local common, uninsulated, lightweight construction (Case B. The thermal model was calibrated by comparing hourly temperature values of the observed and the predicted indoor air temperature. A high correlation level (R2 was achieved between the observed and predicted data; 0.89 in Case A and 0.94 in Case B. The results show that the roof, floor, and the airtightness are the critical building parameters affecting the indoor thermal environment. Likewise, the indoor air temperature is increased up to 4 °C through the implementation of traditional strategies. However, despite the rise in indoor air temperature, acceptable thermal comfort ranges were only reached for 25% of the total hours.

  12. Junction temperature measurements via thermo-sensitive electrical parameters and their application to condition monitoring and active thermal control of power converters

    DEFF Research Database (Denmark)

    Baker, Nick; Liserre, Marco; Dupont, L.

    2013-01-01

    implementation of active thermal control to reduce losses and increase lifetime can be performed given an accurate knowledge of temperature. Temperature measurements via thermo-sensitive electrical parameters (TSEP) are one way to carry out immediate temperature readings on fully packaged devices. However...... scale implementation of these methods are discussed. Their potential use in the aforementioned goals in condition monitoring and active thermal control is also described....

  13. Thermal testing of solid neutron shielding materials

    International Nuclear Information System (INIS)

    Boonstra, R.H.

    1993-01-01

    In May-June 1989 the first series of full-scale thermal tests was performed on three shielding materials: Bisco Products NS-4-FR, and Reactor Experiments RX-201 and RX-207. The tests are described in Thermal Testing of Solid Neutron Shielding Materials, GA-A19897, R.H. Boonstra, General Atomics (1990), and demonstrated the acceptability of these materials in a thermal accident. Subsequent design changes to the cask rendered these materials unattractive in terms of weight or adequate service temperature margin. For the second test series a material specification was developed for a polypropylene based neutron shield with a softening point of at least 280degF. Table 1 lists the neutron shield materials tested. The Envirotech and Bisco materials are not polypropylene, but were tested as potential backup materials in the event that a satisfactory polypropylene could not be found. The Bisco modified NS-4 and Reactor Experiments HMPP are both acceptable materials from a thermal accident standpoint for use in the shipping cask. Tests of the Kobe PP-R01 and Envirotech HDPE were stopped for safety reasons, due to inability to deal with the heavy smoke, before completion of the 30-minute heating phase. However these materials may prove satisfactory if they could undergo the complete heating. (J.P.N.)

  14. Personal values and pain tolerance: does a values intervention add to acceptance?

    Science.gov (United States)

    Branstetter-Rost, Ann; Cushing, Christopher; Douleh, Tanya

    2009-08-01

    Previous research suggests that acceptance is a promising alternative to distraction and control techniques in successfully coping with pain. Acceptance interventions based upon Acceptance and Commitment Therapy (ACT) have been shown to lead to greater tolerance of acute pain as well as increased adjustment and less disability among individuals with chronic pain. However, in these previous intervention studies, the ACT component of values has either not been included or not specifically evaluated. The current study compares the effects of an ACT-based acceptance intervention with and without the values component among individuals completing the cold-pressor task. Results indicate that inclusion of the values component (n = 34) of ACT leads to significantly greater pain tolerance than acceptance alone (n = 30). Consistent with previous research, both conditions were associated with greater pain tolerance than control (n = 35). Despite the difference in tolerance, pain threshold did not differ, and participants in the control condition provided lower ratings of pain severity. The findings from this study support the important role of values and values clarification in acceptance-based interventions such as ACT, and provide direction for clinicians working with individuals with chronic pain conditions. This article evaluates the additive effect of including a personalized-values exercise in an acceptance-based treatment for pain. Results indicate that values interventions make a significant contribution and improvement to acceptance interventions, which may be of interest to clinicians who provide psychological treatment to individuals with chronic pain.

  15. Behavioural responses to thermal conditions affect seasonal mass change in a heat-sensitive northern ungulate.

    Directory of Open Access Journals (Sweden)

    Floris M van Beest

    Full Text Available BACKGROUND: Empirical tests that link temperature-mediated changes in behaviour (activity and resource selection to individual fitness or condition are currently lacking for endotherms yet may be critical to understanding the effect of climate change on population dynamics. Moose (Alces alces are thought to suffer from heat stress in all seasons so provide a good biological model to test whether exposure to non-optimal ambient temperatures influence seasonal changes in body mass. Seasonal mass change is an important fitness correlate of large herbivores and affects reproductive success of female moose. METHODOLOGY/PRINCIPAL FINDINGS: Using GPS-collared adult female moose from two populations in southern Norway we quantified individual differences in seasonal activity budget and resource selection patterns as a function of seasonal temperatures thought to induce heat stress in moose. Individual body mass was recorded in early and late winter, and autumn to calculate seasonal mass changes (n = 52 over winter, n = 47 over summer. We found large individual differences in temperature-dependent resource selection patterns as well as within and between season variability in thermoregulatory strategies. As expected, individuals using an optimal strategy, selecting young successional forest (foraging habitat at low ambient temperatures and mature coniferous forest (thermal shelter during thermally stressful conditions, lost less mass in winter and gained more mass in summer. CONCLUSIONS/SIGNIFICANCE: This study provides evidence that behavioural responses to temperature have important consequences for seasonal mass change in moose living in the south of their distribution in Norway, and may be a contributing factor to recently observed declines in moose demographic performance. Although the mechanisms that underlie the observed temperature mediated habitat-fitness relationship remain to be tested, physiological state and individual variation in

  16. Behavioural responses to thermal conditions affect seasonal mass change in a heat-sensitive northern ungulate.

    Science.gov (United States)

    van Beest, Floris M; Milner, Jos M

    2013-01-01

    Empirical tests that link temperature-mediated changes in behaviour (activity and resource selection) to individual fitness or condition are currently lacking for endotherms yet may be critical to understanding the effect of climate change on population dynamics. Moose (Alces alces) are thought to suffer from heat stress in all seasons so provide a good biological model to test whether exposure to non-optimal ambient temperatures influence seasonal changes in body mass. Seasonal mass change is an important fitness correlate of large herbivores and affects reproductive success of female moose. Using GPS-collared adult female moose from two populations in southern Norway we quantified individual differences in seasonal activity budget and resource selection patterns as a function of seasonal temperatures thought to induce heat stress in moose. Individual body mass was recorded in early and late winter, and autumn to calculate seasonal mass changes (n = 52 over winter, n = 47 over summer). We found large individual differences in temperature-dependent resource selection patterns as well as within and between season variability in thermoregulatory strategies. As expected, individuals using an optimal strategy, selecting young successional forest (foraging habitat) at low ambient temperatures and mature coniferous forest (thermal shelter) during thermally stressful conditions, lost less mass in winter and gained more mass in summer. This study provides evidence that behavioural responses to temperature have important consequences for seasonal mass change in moose living in the south of their distribution in Norway, and may be a contributing factor to recently observed declines in moose demographic performance. Although the mechanisms that underlie the observed temperature mediated habitat-fitness relationship remain to be tested, physiological state and individual variation in thermal tolerance are likely contributory factors. Climate-related effects on animal

  17. Environmental conditions using thermal-hydraulics computer code GOTHIC for beyond design basis external events

    International Nuclear Information System (INIS)

    Pleskunas, R.J.

    2015-01-01

    In response to the Fukushima Dai-ichi beyond design basis accident in March 2011, the Nuclear Regulatory Commission (NRC) issued Order EA-12-049, 'Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies Beyond-Design-Basis-External-Events'. To outline the process to be used by individual licensees to define and implement site-specific diverse and flexible mitigation strategies (FLEX) that reduce the risks associated with beyond design basis conditions, Nuclear Energy Institute document NEI 12-06, 'Diverse and Flexible Coping Strategies (FLEX) Implementation Guide', was issued. A beyond design basis external event (BDBEE) is postulated to cause an Extended Loss of AC Power (ELAP), which will result in a loss of ventilation which has the potential to impact room habitability and equipment operability. During the ELAP, portable FLEX equipment will be used to achieve and maintain safe shutdown, and only a minimal set of instruments and controls will be available. Given these circumstances, analysis is required to determine the environmental conditions in several vital areas of the Nuclear Power Plant. The BDBEE mitigating strategies require certain room environments to be maintained such that they can support the occupancy of personnel and the functionality of equipment located therein, which is required to support the strategies associated with compliance to NRC Order EA-12-049. Three thermal-hydraulic analyses of vital areas during an extended loss of AC power using the GOTHIC computer code will be presented: 1) Safety-related pump and instrument room transient analysis; 2) Control Room transient analysis; and 3) Auxiliary/Control Building transient analysis. GOTHIC (Generation of Thermal-Hydraulic Information for Containment) is a general purpose thermal-hydraulics software package for the analysis of nuclear power plant containments, confinement buildings, and system components. It is a volume/path/heat sink

  18. Guidelines for CubeSat's Thermal Design

    Science.gov (United States)

    Rodriguez-Ruiz, Juan; Patel, Deepak

    2015-01-01

    Thermal and Fluids Analysis Workshop 2015, Silver Spring, MD. NCTS 19104-15. What does it take to thermally designlow cost, low mass cubesats? What are the differences in the approach when you compare with large scale missions?What additional risk is acceptable? What is the approach to hardware? How is the testing campaign run? These aresome of the questions that will be addressed in this course, which is designed to equip the attendees to support thedevelopment of cubesats at their organization.

  19. Constraining Non-thermal and Thermal properties of Dark Matter

    Directory of Open Access Journals (Sweden)

    Bhupal eDev

    2014-05-01

    Full Text Available We describe the evolution of Dark Matter (DM abundance from the very onset of its creation from inflaton decay under the assumption of an instantaneous reheating. Based on the initial conditions such as the inflaton mass and its decay branching ratio to the DM species, the reheating temperature, and the mass and interaction rate of the DM with the thermal bath, the DM particles can either thermalize (fully/partially with the primordial bath or remain non-thermal throughout their evolution history. In the thermal case, the final abundance is set by the standard freeze-out mechanism for large annihilation rates, irrespective of the initial conditions. For smaller annihilation rates, it can be set by the freeze-in mechanism which also does not depend on the initial abundance, provided it is small to begin with. For even smaller interaction rates, the DM decouples while being non-thermal, and the relic abundance will be essentially set by the initial conditions. We put model-independent constraints on the DM mass and annihilation rate from over-abundance by exactly solving the relevant Boltzmann equations, and identify the thermal freeze-out, freeze-in and non-thermal regions of the allowed parameter space. We highlight a generic fact that inflaton decay to DM inevitably leads to an overclosure of the Universe for a large range of DM parameter space, and thus poses a stringent constraint that must be taken into account while constructing models of DM. For the thermal DM region, we also show the complementary constraints from indirect DM search experiments, Big Bang Nucleosynthesis, Cosmic Microwave Background, Planck measurements, and theoretical limits due to the unitarity of S-matrix. For the non-thermal DM scenario, we show the allowed parameter space in terms of the inflaton and DM masses for a given reheating temperature, and compute the comoving free-streaming length to identify the hot, warm and cold DM regimes.

  20. CARBON-RICH GIANT PLANETS: ATMOSPHERIC CHEMISTRY, THERMAL INVERSIONS, SPECTRA, AND FORMATION CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Madhusudhan, Nikku [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Mousis, Olivier [Institut UTINAM, CNRS-UMR 6213, Observatoire de Besancon, BP 1615, F-25010 Besancon Cedex (France); Johnson, Torrence V. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Lunine, Jonathan I., E-mail: nmadhu@astro.princeton.edu [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States)

    2011-12-20

    The recent inference of a carbon-rich atmosphere, with C/O {>=} 1, in the hot Jupiter WASP-12b motivates the exotic new class of carbon-rich planets (CRPs). We report a detailed study of the atmospheric chemistry and spectroscopic signatures of carbon-rich giant (CRG) planets, the possibility of thermal inversions in their atmospheres, the compositions of icy planetesimals required for their formation via core accretion, and the apportionment of ices, rock, and volatiles in their envelopes. Our results show that CRG atmospheres probe a unique region in composition space, especially at high temperature (T). For atmospheres with C/O {>=} 1, and T {approx}> 1400 K in the observable atmosphere, most of the oxygen is bound up in CO, while H{sub 2}O is depleted and CH{sub 4} is enhanced by up to two or three orders of magnitude each, compared to equilibrium compositions with solar abundances (C/O = 0.54). These differences in the spectroscopically dominant species for the different C/O ratios cause equally distinct observable signatures in the spectra. As such, highly irradiated transiting giant exoplanets form ideal candidates to estimate atmospheric C/O ratios and to search for CRPs. We also find that the C/O ratio strongly affects the abundances of TiO and VO, which have been suggested to cause thermal inversions in highly irradiated hot Jupiter atmospheres. A C/O = 1 yields TiO and VO abundances of {approx}100 times lower than those obtained with equilibrium chemistry assuming solar abundances, at P {approx} 1 bar. Such a depletion is adequate to rule out thermal inversions due to TiO/VO even in the most highly irradiated hot Jupiters, such as WASP-12b. We estimate the compositions of the protoplanetary disk, the planetesimals, and the envelope of WASP-12b, and the mass of ices dissolved in the envelope, based on the observed atmospheric abundances. Adopting stellar abundances (C/O = 0.44) for the primordial disk composition and low-temperature formation conditions

  1. Investigation and modelling of thermal conditions in low flow SDHW systems

    Energy Technology Data Exchange (ETDEWEB)

    Shah, L.J.

    1999-07-01

    The purpose of this study was to characterise the thermal conditions in low flow SDHW systems. As the heat storage has proved to be the most important system component, there has been an emphasis on this component in the study. A literature survey revealed that the mantle tank heat storage type is one of the most promising storage designs and therefore only the mantle tank is investigated in this study. To optimise the design of mantle tanks and low flow SDHW systems, it was found necessary to understand how the thermal stratification is built up in the heat storage. In addition, it was necessary to model the flow and heat transfer in the tanks. Due to the complexity of the problems, CFD-models were used to take mantle tanks into calculation. Two CFD programs were used to model the mantle tank: CFX and Fluent. As the CFD-models formed the basis for the theoretical work, they were validated with experiments. In this study, both thermal measurements and experimentally visualised flow patterns were compared with CFD-predictions. The experimental flow visualisation was carried out with Particle image Velocimetry (PIV). With a transparent glass mantle tank, the structures in the mantle were visualised and compared with the CFD-predicted flow structures in the mantle. The results showed that the mantle flow was highly dominated by buoyancy and the CFD-models were able to model this flow. With a steel mantle tank, different dynamic thermal experiments were carried out in a heat storage test facility. These results were used to evaluate the CFD-predicted temperatures. Inner tank and mantle outlet temperatures were compared to the similar CFD-predictions and a good degree of similarity was found between measured and calculated temperatures. With the verified CFX models a parameter analysis was carried out. Based on this analysis, two Nusselt-Rayleigh heat transfer correlations were developed - one for the convective heat transfer in the mantle and one for the convective

  2. Experimental research on thermal comfort in the university classroom of regular semesters in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Gun Joo; Oh, Geun Sug; Im, Young Bin [Pukyong National University, Busan (Korea, Republic of); Song, Sung Ki [Hiroshima Institute of Technology, Hiroshima (Japan); Ahn, Young Chull [Pusan National University, Busan (Korea, Republic of)

    2011-02-15

    This research has investigated physical variables affecting indoor thermal comfort and subjective responses of thermal comfort of students in a university in Korea in which the weather is oceanic temperate climate, and has been performed to contribute to the research fields of Sustainable Thermal Standard and Adaptive Thermal Comfort (ATC). This research is based on the ISO 7730-2005 standard and the ATC theories and 4 main variables of PMV such as dry bulb temperature (Ta), relative humidity (RH), black bulb temperature (Tg), and air velocity (Va) are measured once a week during two regular semesters. A clothing insulation, a thermal sensation vote (TSV), an acceptability of thermal environment, and a preference for cooling and heating are investigated at the same time using a questionnaire. This study was carried out for 26 weeks during the spring season, from March to June 2009, and the autumn season, from September to December 2009. The main achievements of this study are as follows. Monthly Mean Outdoor Temperature (MMOT) and Operative Temperature (OT) in the classroom during research periods are 7.4{approx}23.3 .deg. C and 17.5{approx}29.0 .deg. C, respectively. The acceptability ratio of thermal environment shows over 80% when the range of OT in the classroom is 17{approx}25 .deg. C, and the range can be applicable to operative index of heating and cooling of classroom. The mean TSV of respondents is almost 'neutral (0)' when the PMV in the classroom moves to 'neutral (0)' and 'slightly cool (-1)', and the TSV is almost '+1.5' when the PMV moves to 'slightly warm (+1)'. The acceptability ratio of thermal environment is slightly different from ASHRAE Standard 55-2004. So it is necessary to more investigate standard range of acceptability of thermal environment in oceanic temperate climate region using much more databases.

  3. A novel louvered fin design to enhance thermal and drainage performances during periodic frosting/defrosting conditions

    International Nuclear Information System (INIS)

    Kim, Min-Hwan; Kim, Hisuk; Kim, Dong Rip; Lee, Kwan-Soo

    2016-01-01

    Highlights: • Thermal and drainage performances of a novel design louvered fin were investigated. • The thermal performance of the asymmetric fin was improved in the re-frosting cycle. • The asymmetric louvered fin exhibited better drainage on the leading edge of fins. • Lower surface tension between fin surface and water droplet improved the drainage. - Abstract: The retention water on fin surface can significantly degrade the thermal performance of heat exchangers under periodic frosting/defrosting conditions, which also leads to a decrease in the energy efficiency of air-source heat pumps. A novel louvered fin design was suggested to improve the drainage and the thermal performance of heat exchanger. The novel louvered fin had an asymmetric louver arrangement by flattening two louvers on the leading edge. The retention water formed on fin surface markedly decreased the heat transfer rate of the conventional symmetric louvered fins in re-frosting cycles. On the other hand, the asymmetric louvered fins improved the drainage performance of the retention water, which enhanced the heat transfer rate. To identify the reason of the difference in drainage performance between two fin geometries, additional experiments were carried out with enlargement models. The improvement in drainage performance of the asymmetric fin design originated from the lowered surface tension between the fin surface and water droplet.

  4. Influence of label information on dark chocolate acceptability.

    Science.gov (United States)

    Torres-Moreno, M; Tarrega, A; Torrescasana, E; Blanch, C

    2012-04-01

    The aim of the present work was to study how the information on product labels influences consumer expectations and their acceptance and purchase intention of dark chocolate. Six samples of dark chocolate, varying in brand (premium and store brand) and in type of product (regular dark chocolate, single cocoa origin dark chocolate and high percentage of cocoa dark chocolate), were evaluated by 109 consumers who scored their liking and purchase intention under three conditions: blind (only tasting the products), expected (observing product label information) and informed (tasting the products together with provision of the label information). In the expected condition, consumer liking was mainly affected by the brand. In the blind condition, differences in liking were due to the type of product; the samples with a high percentage of cocoa were those less preferred by consumers. Under the informed condition, liking of dark chocolates varied depending on both brand and type of product. Premium brand chocolates generated high consumer expectations of chocolate acceptability, which were fulfilled by the sensory characteristics of the products. Store brand chocolates created lower expectations, but when they were tasted they were as acceptable as premium chocolates. Claims of a high percentage of cocoa and single cocoa origin on labels did not generate higher expectations than regular dark chocolates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Thermal processing of bone: in vitro response of mesenchymal cells to bone-conditioned medium.

    Science.gov (United States)

    Sawada, K; Caballé-Serrano, J; Schuldt Filho, G; Bosshardt, D D; Schaller, B; Buser, D; Gruber, R

    2015-08-01

    The autoclaving, pasteurization, and freezing of bone grafts to remove bacteria and viruses, and for preservation, respectively, is considered to alter biological properties during graft consolidation. Fresh bone grafts release paracrine-like signals that are considered to support tissue regeneration. However, the impact of the autoclaving, pasteurization, and freezing of bone grafts on paracrine signals remains unknown. Therefore, conditioned medium was prepared from porcine cortical bone chips that had undergone thermal processing. The biological properties of the bone-conditioned medium were assessed by examining the changes in expression of target genes in oral fibroblasts. The data showed that conditioned medium obtained from bone chips that had undergone pasteurization and freezing changed the expression of adrenomedullin, pentraxin 3, BTB/POZ domain-containing protein 11, interleukin 11, NADPH oxidase 4, and proteoglycan 4 by at least five-fold in oral fibroblasts. Bone-conditioned medium obtained from autoclaved bone chips, however, failed to change the expression of the respective genes. Also, when bone-conditioned medium was prepared from fresh bone chips, autoclaving blocked the capacity of bone-conditioned medium to modulate gene expression. These in vitro results suggest that pasteurization and freezing of bone grafts preserve the release of biologically active paracrine signals, but autoclaving does not. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  6. PENGARUH TECHNOLOGY ACCEPTANCE MODEL DAN PENGEMBANGANNYA DALAM PERILAKU MENGGUNAKAN CORE BANKING SYSTEM

    Directory of Open Access Journals (Sweden)

    Dessanti Putri Sekti Ari

    2017-03-01

    Full Text Available The purpose of this study was to examine the antecedents that affected the acceptance of individuals in using theCore Banking System through the constructs Technology Acceptance Model and its development. Constructsused in this study were perceived usefulness, perceived ease of use, attitude, social influences, behavioral inten-tion, facilitating conditions, and behavior. Data were collected through survey methods. The samples of thisstudy were employees working in commercial banks in Malang Raya. This study used 136 respondents and wasanalyzed by smart PLS. The result of this study was that the construct of perceived usefulness and perceived easeof use in the Technology Acceptance Model affected attitude and behavior. Attitude and behavior in the Technol-ogy Acceptance Model and social influence which was the development of the Technology Acceptance Modelaffected behavioral intention to use the Core Banking System, as well as the construct of behavioral intention inTechnology Acceptance Model affected behavior, whereas construct of facilitating conditions which was thedevelopment of the Technology Acceptance Model did not affect the behavior on using the Core Banking System.

  7. Thermal conductivity of sintered UO2 under in-pile conditions

    International Nuclear Information System (INIS)

    Stora, J.P.; Bernardy De Sigoyer, B.; Delmas, R.; Deschamps, P.; Lavaud, B.; Ringot, C.

    1964-01-01

    The temperature distribution in a stack of sintered UO 2 cylinders has been studied both in the laboratory where the heat energy is produced by an axial heating element, and in-pile, where the heating is due solely to nuclear effects. Under a high thermal gradient the UO 2 cracks both along radial planes and along pseudo-cylindrical surfaces: these latter act as thermal barriers to the heat flow, It is therefore an apparent thermal conductivity k a (T), lower than the intrinsic value k(T) of this parameter which is measured. The efficiency of these barriers decreases when the gap decreases and when the external pressure acting on the cracked stack increases: in the limiting case, for high values of the binding strain, k a (T) ≅ k(T). In the domain of phonon conduction (T ≤ 1350 deg C), the expression kw.cm -1 .C -1 =1/(11+0.024*T) accounts for the real thermal conductivity. Above 1350 deg C the thermal conductivity increases. Two in-pile measurements up to 1250 deg C carried out using cartridges fitted with thermocouples confirm, within the limits of experimental error, the above expression and the qualitative effects of the binding strains. Similar tests have been carried out-of-pile and in-pile on the real shape of the EL-4 fuel 'pencils'. Out-of-pile, the influence of the initial free gap, of the nature of the gas filing the 'pencil' and of the external pressure have been studied; the results are compatible with the above interpretation; It appears that an external pressure of 60 kg/cm 2 is insufficient to restore completely the thermal conductivity of the fuel. (authors) [fr

  8. Single walled carbon nanotubes on MHD unsteady flow over a porous wedge with thermal radiation with variable stream conditions

    Directory of Open Access Journals (Sweden)

    R. Kandasamy

    2016-03-01

    Full Text Available The objective of the present work was to investigate theoretically the effect of single walled carbon nanotubes (SWCNTs in the presence of water and seawater with variable stream condition due to solar radiation energy. The conclusion is drawn that the flow motion and the temperature field for SWCNTs in the presence of base fluid are significantly influenced by magnetic field, convective radiation and thermal stratification. Thermal boundary layer of SWCNTs-water is compared to that of Cu-water, absorbs the incident solar radiation and transits it to the working fluid by convection.

  9. Thermal performance of air-conditioned office buildings constructed with inclined walls in different climates in China

    International Nuclear Information System (INIS)

    Chan, A.L.S.; Chow, T.T.

    2014-01-01

    Highlights: • A generic fully air-conditioned office building with inclined walls was modeled. • Simulations were run under climatic conditions in three modern cities in China. • Reduction in cooling load can outweigh the increase in heating load for Hong Kong. • Inclined angle of 30° is appropriate for inverted pyramidal building in Hong Kong. • Building constructed with inclined walls is not encouraged in Shanghai and Beijing. - Abstract: An inverted pyramidal building is built with inclined walls instead of the traditional vertical façades. In terms of thermal performance, an inverted pyramidal building can provide a self-shading effect against the beam solar radiation, leading to a reduction in solar heat gain as well as building cooling load. On the other hand, the heating requirement of an inverted pyramidal building will be increased in winter. There is a strong dependency of building performance on the climatic condition. In this study, a generic air-conditioned office building with inclined walls set at different inclination angles was modeled using a building energy simulation program. Computer simulations were run to assess the thermal performance of the building constructed with inclined walls under different climatic conditions in three modern cities in China–Hong Kong, Shanghai and Beijing. The results reveal that for the building cases with inclined walls set at different inclination angles in subtropical Hong Kong, the saving in annual cooling load ranges from 0.6% to 10.9% and can outweigh the increase in heating load. Moreover, an inclination angle of 30° was found as a better design option for an inverted pyramidal building with symmetrical layout design under the climatic condition in Hong Kong. For the other two cities: Shanghai and Beijing, the saving in cooling load due to self-shading effect cannot offset the increased heating requirement. Design and construction of an inverted pyramidal building is not encouraged in these two

  10. Determination of equilibrium composition of thermally ionized monoatomic gas under different physical conditions

    Science.gov (United States)

    Romanova, M. S.; Rydalevskaya, M. A.

    2017-05-01

    Perfect gas mixtures that result from thermal ionization of spatially and chemically homogeneous monoatomic gases are considered. Equilibrium concentrations of the components of such mixtures are determined using integration over the momentum space and summation with respect to energy levels of the distribution functions that maximize the entropy of system under condition for constancy of the total number of nuclei and electrons. It is demonstrated that such a method allows significant simplification of the calculation of the equilibrium composition for ionized mixtures at different temperatures and makes it possible to study the degree of ionization of gas versus gas density and number in the periodic table of elements.

  11. Effect of the insulation materials filling on the thermal performance of sintered hollow bricks under the air-conditioning intermittent operation

    Directory of Open Access Journals (Sweden)

    Chaoping Hou

    2018-06-01

    Full Text Available Wall insulation performance is an important factor affecting building energy consumption and indoor comfortable level. This study proposes that the insulation materials are filled into the cavities of the sintered hollow brick to replace the single insulation layer. The physical models of typical walls were built by the hollow bricks filled with expanding polystyrene board (EPS in cavities and wall thermal performance is numerically analyzed by the Finite Volume Method under air-conditioning intermittent operation, which conforms to the actual operation rules of air-conditioning. Results show that filling EPS in cavities is beneficial to improve the thermal performance of the bricks, and the larger the EPS filling ratio, the higher the thermal performance improvement. The EPS filling ratio increase has the higher sensitivity on inner surface heat flow under the low EPS filling ratio, and filling EPS in the external cavities is optimum with the decrement rate 5.92% higher than filling EPS in internal cavities for the EPS filling ratio of 20%, while filling EPS in internal and external cavities simultaneously is optimum with decrement rate 2.45%–6.87% higher than that with filling EPS in the internal cavities for the EPS filling ratio of 40%–80%. Keywords: Insulation filling ratio, Insulation filling location, Thermal performance, Sintered hollow bricks

  12. (6) Oriola thermal paper IJAAR

    African Journals Online (AJOL)

    Adeyinka Odunsi

    harvest coupled with non-‐availability of acceptable storage alternatives. This practice leads to ... of tuber age and moisture content on the thermal properties of cassava roots. Freshly harvested ... processed into starch, chips, high quality cassava flour ... for other crops such as sweet potato and yam. (Oke et al., 2007; Farinu ...

  13. Exploring E-Learning Acceptance among University Students in Thailand: A National Survey

    Science.gov (United States)

    Teo, Timothy; Ruangrit, Nammon; Khlaisang, Jintavee; Thammetar, Thapanee; Sunphakitjumnong, Kobkul

    2014-01-01

    This study surveys the e-learning acceptance of university students in Thailand. One thousand nine hundred and eighty-one (1,981) participants completed the E-Learning Acceptance Measure (Teo, 2010) which measures three constructs that predict e-learning acceptance (tutor quality, perceived usefulness, and facilitating conditions). Data analysis…

  14. Correlation of denitrification-accepted fraction of electrons with NAD(P)H fluorescence for Pseudomonas aeruginosa performing simultaneous denitrification and respiration at extremely low dissolved oxygen conditions.

    Science.gov (United States)

    Chen, Fan; Xia, Qing; Ju, Lu-Kwang

    2004-01-01

    In cystic fibrosis airway infection, Pseudomonas aeruginosa forms a microaerobic biofilm and undergoes significant physiological changes. It is important to understand the bacterium's metabolism at microaerobic conditions. In this work, the culture properties and two indicators (the denitrification-accepted e- fraction and an NAD(P)H fluorescence fraction) for the culture's "fractional approach" to a fully anaerobic denitrifying state were examined in continuous cultures with practically zero DO but different aeration rates. With decreasing aeration, specific OUR decreased while specific NAR and NIR increased and kept Y(ATP/S) relatively constant. P. aeruginosa thus appeared to effectively compensate for energy generation at microaerobic conditions with denitrification. At the studied dilution rate of 0.06 h(-1), the maximum specific OUR was 2.8 mmol O2/g cells-h and the Monod constant for DO, in the presence of nitrate, was extremely low (Y(X/S) increased significantly (from 0.24 to 0.34) with increasing aeration, attributed to a roughly opposite trend of Y(ATP/X) (ATP generation required for cell growth). As for the denitrification-accepted e- fraction and the fluorescence fraction, both decreased with increasing aeration as expected. The two fractions, however, were not directly proportional. The fluorescence fraction changed more rapidly than the e- fraction at very low aeration rates, whereas the opposite was true at higher aeration. The results demonstrated the feasibility of using online NAD(P)H fluorescence to monitor sensitive changes of cellular physiology and provided insights to the shift of e- -accepting mechanisms of P. aeruginosa under microaerobic conditions.

  15. Frontal brain activity and behavioral indicators of affective states are weakly affected by thermal stimuli in sheep living in different housing conditions

    Directory of Open Access Journals (Sweden)

    Sabine eVögeli

    2015-05-01

    Full Text Available Many stimuli evoke short-term emotional reactions. These reactions may play an important role in assessing how a subject perceives a stimulus. Additionally, long-term mood may modulate the emotional reactions but it is still unclear in what way. The question seems to be important in terms of animal welfare, as a negative mood may taint emotional reactions. In the present study with sheep, we investigated the effects of thermal stimuli on emotional reactions and the potential modulating effect of mood induced by manipulations of the housing conditions. We assume that unpredictable, stimulus-poor conditions lead to a negative and predictable, stimulus-rich conditions to a positive mood state. The thermal stimuli were applied to the upper breast during warm ambient temperatures: hot (as presumably negative, intermediate, and cold (as presumably positive. We recorded cortical activity by functional near-infrared spectroscopy, restlessness behavior (e.g. locomotor activity, aversive behaviors and ear postures as indicators of emotional reactions. The strongest hemodynamic reaction was found during a stimulus of intermediate valence independent of the animal’s housing conditions, whereas locomotor activity, ear movements and aversive behaviors were seen most in sheep from the unpredictable, stimulus-poor housing conditions, independent of stimulus valence. We conclude that, sheep perceived the thermal stimuli and differentiated between some of them. An adequate interpretation of the neuronal activity pattern remains difficult, though. The effects of housing conditions were small indicating that the induction of mood was only modestly efficacious. Therefore, a modulating effect of mood on the emotional reaction was not found.

  16. Influence of thermal processing conditions on flavor stability in fluid milk: benzaldehyde.

    Science.gov (United States)

    Potineni, R V; Peterson, D G

    2005-01-01

    Flavor loss in dairy products has been associated with enzymatic degradation by xanthine oxidase. This study was conducted to investigate the influence of milk thermal processing conditions (or xanthine oxidase inactivation) on benzaldehyde stability. Benzaldehyde was added to whole milk which had been thermally processed at 4 levels: (1) none or raw, (2) high temperature, short time (HTST) pasteurization, (3) HTST pasteurization, additionally heated to 100 degrees C (PAH), and (4) UHT sterilized. Additionally, PAH and UHT milk samples containing benzaldehyde (with and without ferrous sulfate) were spiked with xanthine oxidase. Azide was added as an antimicrobial agent (one additional pasteurized sample without) and the microbial load (total plate count) was determined on d 0, 2, and 6. The concentration of benzaldehyde and benzoic acid in all milk samples were determined at d 0, 1, 2, 4, and 6 (stored at 5 degrees C) by gas chromatography/mass spectrometry in selective ion monitory mode. Over the 6-d storage period, more than 80% of the benzaldehyde content was converted (oxidized) to benzoic acid in raw and pasteurized milk, whereas no change in the benzaldehyde concentration was found in PAH or UHT milk samples. Furthermore, the addition of xanthine oxidase or xanthine oxidase plus ferrous sulfate to PAH or UHT milk samples did not result in benzaldehyde degradation over the storage period.

  17. Identifying Time Periods of Minimal Thermal Gradient for Temperature-Driven Structural Health Monitoring

    Directory of Open Access Journals (Sweden)

    John Reilly

    2018-03-01

    Full Text Available Temperature changes play a large role in the day to day structural behavior of structures, but a smaller direct role in most contemporary Structural Health Monitoring (SHM analyses. Temperature-Driven SHM will consider temperature as the principal driving force in SHM, relating a measurable input temperature to measurable output generalized strain (strain, curvature, etc. and generalized displacement (deflection, rotation, etc. to create three-dimensional signatures descriptive of the structural behavior. Identifying time periods of minimal thermal gradient provides the foundation for the formulation of the temperature–deformation–displacement model. Thermal gradients in a structure can cause curvature in multiple directions, as well as non-linear strain and stress distributions within the cross-sections, which significantly complicates data analysis and interpretation, distorts the signatures, and may lead to unreliable conclusions regarding structural behavior and condition. These adverse effects can be minimized if the signatures are evaluated at times when thermal gradients in the structure are minimal. This paper proposes two classes of methods based on the following two metrics: (i the range of raw temperatures on the structure, and (ii the distribution of the local thermal gradients, for identifying time periods of minimal thermal gradient on a structure with the ability to vary the tolerance of acceptable thermal gradients. The methods are tested and validated with data collected from the Streicker Bridge on campus at Princeton University.

  18. Identifying Time Periods of Minimal Thermal Gradient for Temperature-Driven Structural Health Monitoring.

    Science.gov (United States)

    Reilly, John; Glisic, Branko

    2018-03-01

    Temperature changes play a large role in the day to day structural behavior of structures, but a smaller direct role in most contemporary Structural Health Monitoring (SHM) analyses. Temperature-Driven SHM will consider temperature as the principal driving force in SHM, relating a measurable input temperature to measurable output generalized strain (strain, curvature, etc.) and generalized displacement (deflection, rotation, etc.) to create three-dimensional signatures descriptive of the structural behavior. Identifying time periods of minimal thermal gradient provides the foundation for the formulation of the temperature-deformation-displacement model. Thermal gradients in a structure can cause curvature in multiple directions, as well as non-linear strain and stress distributions within the cross-sections, which significantly complicates data analysis and interpretation, distorts the signatures, and may lead to unreliable conclusions regarding structural behavior and condition. These adverse effects can be minimized if the signatures are evaluated at times when thermal gradients in the structure are minimal. This paper proposes two classes of methods based on the following two metrics: (i) the range of raw temperatures on the structure, and (ii) the distribution of the local thermal gradients, for identifying time periods of minimal thermal gradient on a structure with the ability to vary the tolerance of acceptable thermal gradients. The methods are tested and validated with data collected from the Streicker Bridge on campus at Princeton University.

  19. Effect of the position of the visible sky in determining the sky view factor on micrometeorological and human thermal comfort conditions in urban street canyons

    Science.gov (United States)

    Qaid, Adeb; Lamit, Hasanuddin Bin; Ossen, Dilshan Remaz; Rasidi, Mohd Hisyam

    2018-02-01

    Poor daytime and night-time micrometeorological conditions are issues that influence the quality of environmental conditions and can undermine a comfortable human lifestyle. The sky view factor (SVF) is one of the essential physical parameters used to assess the micrometeorological conditions and thermal comfort levels within city streets. The position of the visible sky relative to the path of the sun, in the cardinal and ordinal directions, has not been widely discerned as a parameter that could have an impact on the micrometeorological conditions of urban streets. To investigate this parameter, different urban streets that have a similar SVF value but diverse positions of visible sky were proposed in different street directions intersecting with the path of the sun, namely N-S, NE-SW and NW-SE. The effects of daytime and night-time micrometeorological variables and human thermal comfort variables on the street were investigated by applying ENVI-met V3.1 Beta software. The results show that the position of the visible sky has a greater influence on the street's meteorological and human thermal comfort conditions than the SVF value. It has the ability to maximise or minimise the mean radiation temperature (Tmrt, °C) and the physiological equivalent temperature (PET, °C) at street level. However, the visible sky positioned to the zenith in a NE-SW or N-S street direction and to the SW of a NW-SE street direction achieves the best daytime micrometeorological and thermal comfort conditions. Alternatively, the visible sky positioned to the NE for a NW-SE street direction, to the NW and the zenith for a NE-SW street direction and to the zenith for a N-S street direction reduces the night-time air temperature (Ta, °C). Therefore, SVF and the position of the visible sky relative to the sun's trajectory, in the cardinal and ordinal directions, must be considered during urban street planning to better understand the resultant micrometeorological and human thermal

  20. The role of heater thermal response in reactor thermal limits during oscillartory two-phase flows

    Energy Technology Data Exchange (ETDEWEB)

    Ruggles, A.E.; Brown, N.W. [Univ. of Tennessee, Knoxville, TN (United States); Vasil`ev, A.D. [Nuclear Safety Institute, Moscow, (Russian Federation); Wendel, M.W. [Oak Ridge National Lab., TN (United States)

    1995-09-01

    Analytical and numerical investigations of critical heat flux (CHF) and reactor thermal limits are conducted for oscillatory two-phase flows often associated with natural circulation conditions. It is shown that the CHF and associated thermal limits depend on the amplitude of the flow oscillations, the period of the flow oscillations, and the thermal properties and dimensions of the heater. The value of the thermal limit can be much lower in unsteady flow situations than would be expected using time average flow conditions. It is also shown that the properties of the heater strongly influence the thermal limit value in unsteady flow situations, which is very important to the design of experiments to evaluate thermal limits for reactor fuel systems.

  1. Effects of varying environmental conditions on emissivity spectra of bulk lunar soils: Application to Diviner thermal infrared observations of the Moon

    Science.gov (United States)

    Donaldson Hanna, K. L.; Greenhagen, B. T.; Patterson, W. R.; Pieters, C. M.; Mustard, J. F.; Bowles, N. E.; Paige, D. A.; Glotch, T. D.; Thompson, C.

    2017-02-01

    Currently, few thermal infrared measurements exist of fine particulate (samples (e.g. minerals, mineral mixtures, rocks, meteorites, and lunar soils) measured under simulated lunar conditions. Such measurements are fundamental for interpreting thermal infrared (TIR) observations by the Diviner Lunar Radiometer Experiment (Diviner) onboard NASA's Lunar Reconnaissance Orbiter as well as future TIR observations of the Moon and other airless bodies. In this work, we present thermal infrared emissivity measurements of a suite of well-characterized Apollo lunar soils and a fine particulate (sample as we systematically vary parameters that control the near-surface environment in our vacuum chamber (atmospheric pressure, incident solar-like radiation, and sample cup temperature). The atmospheric pressure is varied between ambient (1000 mbar) and vacuum (radiation is varied between 52 and 146 mW/cm2, and the sample cup temperature is varied between 325 and 405 K. Spectral changes are characterized as each parameter is varied, which highlight the sensitivity of thermal infrared emissivity spectra to the atmospheric pressure and the incident solar-like radiation. Finally spectral measurements of Apollo 15 and 16 bulk lunar soils are compared with Diviner thermal infrared observations of the Apollo 15 and 16 sampling sites. This comparison allows us to constrain the temperature and pressure conditions that best simulate the near-surface environment of the Moon for future laboratory measurements and to better interpret lunar surface compositions as observed by Diviner.

  2. Impact of an Acceptance Facilitating Intervention on Patients' Acceptance of Internet-based Pain Interventions: A Randomized Controlled Trial.

    Science.gov (United States)

    Baumeister, Harald; Seifferth, Holger; Lin, Jiaxi; Nowoczin, Lisa; Lüking, Marianne; Ebert, David

    2015-06-01

    Results from clinical trials indicate that Internet-based psychological pain interventions are effective in treating chronic pain. However, little is known about patients' acceptance of these programs and how to positively influence patients' intention to engage in them. Therefore, the present study aimed (1) to assess patients' acceptance of Internet-based interventions, and (2) to examine whether patients' acceptance can be increased by an acceptance facilitating intervention. A total of 104 patients with chronic pain from 2 pain units were randomly allocated to an intervention group (IG) and a no-intervention control group (CG). The IG was shown a short informational video about Internet-based psychological pain interventions before receiving a questionnaire on patients' acceptance of Internet-based psychological pain interventions and predictors of acceptance (performance expectancy, effort expectancy, social influence, facilitating conditions, Internet usage, and Internet anxiety). The CG filled out the questionnaire immediately. Patients' acceptance was measured with a 4-item scale (sum score ranging from 4 to 20). Baseline acceptance of Internet-based interventions was reported as low (sum-score:4-9) by 53.8%, moderate (10 to 15) by 42.3%, and high (16 to 20) by 3.9% of the patients with chronic pain in the CG. The IG showed a significantly higher acceptance (M = 12.17, SD = 4.22) than the CG (M = 8.94, SD = 3.71) with a standardized mean difference of d = 0.81 (95% CI, 0.41, 1.21). All predictor variables were significantly improved in the IG compared with the CG, except for Internet usage. Patients with chronic pain display a relatively low acceptance of Internet-based psychological pain interventions, which can be substantially increased by a short informational video.

  3. Influence of nanoparticle addition on the formation and growth of intermetallic compounds (IMCs) in Cu/Sn–Ag–Cu/Cu solder joint during different thermal conditions

    International Nuclear Information System (INIS)

    Ting Tan, Ai; Wen Tan, Ai; Yusof, Farazila

    2015-01-01

    Nanocomposite lead-free solders are gaining prominence as replacements for conventional lead-free solders such as Sn–Ag–Cu solder in the electronic packaging industry. They are fabricated by adding nanoparticles such as metallic and ceramic particles into conventional lead-free solder. It is reported that the addition of such nanoparticles could strengthen the solder matrix, refine the intermetallic compounds (IMCs) formed and suppress the growth of IMCs when the joint is subjected to different thermal conditions such as thermal aging and thermal cycling. In this paper, we first review the fundamental studies on the formation and growth of IMCs in lead-free solder joints. Subsequently, we discuss the effect of the addition of nanoparticles on IMC formation and their growth under several thermal conditions. Finally, an outlook on the future growth of research in the fabrication of nanocomposite solder is provided. (review)

  4. Thermodynamic analysis of a low-temperature organic Rankine cycle power plant operating at off-design conditions

    International Nuclear Information System (INIS)

    He, Zhonglu; Zhang, Yufeng; Dong, Shengming; Ma, Hongting; Yu, Xiaohui; Zhang, Yan; Ma, Xuelian; Deng, Na; Sheng, Ying

    2017-01-01

    Highlights: • An ORC power plant driven by low grade heat source is set up. • Energy and exergy analysis at off-design conditions is conducted. • The twin screw expander performance is characterized. • An empirical model to predict the net power output and thermal efficiency. - Abstract: This paper deals with an experimental study on a 50-kW Organic Rankine cycle (ORC) power generation plant driven by low-grade heat source. Hot water boiler and solar-thermal system were used as the low-grade heat source providing hot water at temperature ranging from 65 to 95 °C. A twin screw compressor has been modified as the expansion machine in the ORC module and its expansion efficiency under variable operating conditions was tested in the experiments. This work was purposed to assess the ORC system and get the performance map at off-design operating conditions in a typical year from the view of the first and the second law of thermodynamics. The maximum electricity production and thermal efficiency were 46.5 kW and 6.52% respectively at the optimal operating condition. The highest exergetic efficiency reached 36.3% and the exergy analysis showed that evaporation pressure and condensation pressure were the key parameters to influence the exergy flow and exergetic efficiency. Furthermore, by fitting the actual plant data obtained in different months, an empirical model has been developed to predict the net power output and thermal efficiency with acceptable accuracy. Lastly, as an illustration, the empirical model is used to analyze the performance of the solar-driven ORC system.

  5. Improving PAQ and comfort conditions in Spanish office buildings with passive climate control

    Energy Technology Data Exchange (ETDEWEB)

    Orosa, Jose A.; Baalina, A. [Departamento de Energia y P.M. Escuela Tecnica Superior de N. y M, Universidade da Coruna, Paseo de Ronda 51, P.C.:15011 A Coruna (Spain)

    2009-03-15

    Some researchers have demonstrated that passive moisture transfer between indoor air and hygroscopic structures has the potential to moderate variations of indoor air relative humidity and, thus, to improve comfort and PAQ [Simonson CJ, Salonvaara M, Ojalen T. The effect of structures on indoor humidity-possibility to improve comfort and perceived air quality. Indoor Air 2002; 12: 243-51; Simonson CJ, Salonvaara M, Ojalen T. Improving indoor climate and comfort with wooden structures. Espoo 2001. Technical Research Centre of Finland, VTT Publications 431.200p+app 91p]. The main objective of this study is to show the internal wall coating effect on indoor air conditions and, as a consequence of this, in comfort conditions and PAQ. In a previous paper [Orosa JA, Baalina A. Passive climate control in Spanish office buildings for long periods of time. Building and Environment 2008], we analysed the influence of permeable and impermeable materials on indoor air conditions, during the unoccupied period, in 25 office buildings in different seasons. Results obtained lead us to conclude that real coverings such as permeable, semi-permeable and impermeable types, present different behavioural patterns in indoor air conditions. Furthermore, we concluded that an absorbent structure will moderate relative humidity indoors. In this paper, we study this indoor relative humidity effect on local thermal discomfort, due to decreased respiratory cooling, and indoor ambience acceptability for the early hours of morning applying PD and Acc models [Toftum J, Jorgensen AS, Fanger PO. Upper limits for indoor air humidity to avoid uncomfortably humid skin. Energy and buildings 1998; 28: 1-13; Toftum J, Jorgensen AS, Fanger PO. Upper limits of air humidity for preventing warm respiratory discomfort. Energy and Buildings 1998; 28: 15-23] such as that proposed by Simonson et al. [The effect of structures on indoor humidity-possibility to improve comfort and perceived air quality. Indoor Air

  6. Radwaste characteristics and Disposal Facility Waste Acceptance Criteria

    International Nuclear Information System (INIS)

    Sung, Suk Hyun; Jeong, Yi Yeong; Kim, Ki Hong

    2008-01-01

    The purpose of Radioactive Waste Acceptance Criteria (WAC) is to verify a radioactive waste compliance with radioactive disposal facility requirements in order to maintain a disposal facility's performance objectives and to ensure its safety. To develop WAC which is conformable with domestic disposal site conditions, we furthermore analysed the WAC of foreign disposal sites similar to the Kyung-Ju disposal site and the characteristics of various wastes which are being generated from Korea nuclear facilities. Radioactive WAC was developed in the technical cooperation with the Korea Atomic Energy Research Institute in consideration of characteristics of the wastes which are being generated from various facilities, waste generators' opinions and other conditions. The established criteria was also discussed and verified at an advisory committee which was comprised of some experts from universities, institutes and the industry. So radioactive WAC was developed to accept all wastes which are being generated from various nuclear facilities as much as possible, ensuring the safety of a disposal facility. But this developed waste acceptance criteria is not a criteria to accept all the present wastes generated from various nuclear facilities, so waste generators must seek an alternative treatment method for wastes which were not worth disposing of, and then they must treat the wastes more to be acceptable at a disposal site. The radioactive disposal facility WAC will continuously complement certain criteria related to a disposal concentration limit for individual radionuclide in order to ensure a long-term safety.

  7. Fission gas behavior during fast thermal transients

    International Nuclear Information System (INIS)

    Esteves, R.G.

    1976-01-01

    The behavior of non-equilibrium fission in fuel elements undergoing fast thermal transients is analyzed. To facilitate the analysis, a new variable, the equilibrium variable (EV) is defined. This variable, together with bubble radius, completely specifies a bubble with respect to its size and equilibrium condition. The analysis is coded using a two-variable (radius and EV) multigroup numerical approximation that accepts as input the time-temperature history, the time-fission rate history, and the time-thermal gradient history of the fuel element. Studies were performed to test the code for convergence with respect to the time interval and the number of groups chosen. For a series of transient simulation studies, the measurements obtained at HEDL (microscopic examination of intragranular porosity in oxide fuel transient-tested in TREAT) are used. Two different transient histories were selected; the first, a high-temperature transient (HTT) with a peak at 2477 0 K and the second, a low-temperature transient (LTT) with a peak-temperature at 2000 0 K. The LTT was simulated for three different conditions: Bubbles were allowed to move via (a) only biased migration, (b) via random migration, and (c) via both mechanisms. The HTT was also run for both mechanisms. The agreement with HEDL microscopic observations was fair for bubbles smaller than 964 A in diameter, and poor for larger bubbles. Bubbles that grew during the heat-up part of the transient were frozen at a larger size during the cool down

  8. The Swedish version of the Acceptance of Chronic Health Conditions Scale for people with multiple sclerosis: Translation, cultural adaptation and psychometric properties.

    Science.gov (United States)

    Forslin, Mia; Kottorp, Anders; Kierkegaard, Marie; Johansson, Sverker

    2016-11-11

    To translate and culturally adapt the Acceptance of Chronic Health Conditions (ACHC) Scale for people with multiple sclerosis into Swedish, and to analyse the psychometric properties of the Swedish version. Ten people with multiple sclerosis participated in translation and cultural adaptation of the ACHC Scale; 148 people with multiple sclerosis were included in evaluation of the psychometric properties of the scale. Translation and cultural adaptation were carried out through translation and back-translation, by expert committee evaluation and pre-test with cognitive interviews in people with multiple sclerosis. The psychometric properties of the Swedish version were evaluated using Rasch analysis. The Swedish version of the ACHC Scale was an acceptable equivalent to the original version. Seven of the original 10 items fitted the Rasch model and demonstrated ability to separate between groups. A 5-item version, including 2 items and 3 super-items, demonstrated better psychometric properties, but lower ability to separate between groups. The Swedish version of the ACHC Scale with the original 10 items did not fit the Rasch model. Two solutions, either with 7 items (ACHC-7) or with 2 items and 3 super-items (ACHC-5), demonstrated acceptable psychometric properties. Use of the ACHC-5 Scale with super-items is recommended, since this solution adjusts for local dependency among items.

  9. Acceptance test procedure for core sample trucks

    International Nuclear Information System (INIS)

    Smalley, J.L.

    1995-01-01

    The purpose of this Acceptance Test Procedure is to provide instruction and documentation for acceptance testing of the rotary mode core sample trucks, HO-68K-4600 and HO-68K-4647. The rotary mode core sample trucks were based upon the design of the second core sample truck (HO-68K-4345) which was constructed to implement rotary mode sampling of the waste tanks at Hanford. Acceptance testing of the rotary mode core sample trucks will verify that the design requirements have been met. All testing will be non-radioactive and stand-in materials shall be used to simulate waste tank conditions. Compressed air will be substituted for nitrogen during the majority of testing, with nitrogen being used only for flow characterization

  10. A detailed thermal-electrical model of three photovoltaic/thermal (PV/T) hybrid air collectors and photovoltaic (PV) module: Comparative study under Algiers climatic conditions

    International Nuclear Information System (INIS)

    Slimani, Mohamed El Amine; Amirat, Madjid; Kurucz, Ildikó; Bahria, Sofiane; Hamidat, Abderrahmane; Chaouch, Wafa Braham

    2017-01-01

    Highlights: • A detailed thermal and electrical model for PV and PV/T systems has been presented. • The developed numerical model was validated successfully with previously published experimental results. • A comparative study between four solar devices (PV and PV/T systems) was carried out. • The experimental weather conditions of Algiers site are used in the numerical model. • The glazed double-pass photovoltaic/thermal air collector shows the best overall energy efficiency. - Abstract: The thermal photovoltaic hybrid collector is a genuine cogeneration technology; it can produce electricity and heat simultaneously. In this paper, a comparative study is presented between four solar device configurations: photovoltaic module (PV-I), conventional hybrid solar air collector (PV/T-II), glazed hybrid solar air collector (PV/T-III) and glazed double-pass hybrid solar air collector (PV/T-IV). A numerical model is developed and validated through experimental results indicated in the previous literature. The numerical model takes the heat balance equations and different thermal and electrical parameters into account for each configuration included in this study, the energy performances are evaluated with a sample weather data of Algiers site. The numerical results show that the daily average of overall energy efficiency reaches: 29.63%, 51.02%, 69.47% and 74% for the first (PV-I), the second (PV/T-II), the third (PV/T-III) and the fourth (PV/T-IV) configurations respectively. These values are obtained with an air flow of 0.023 kg/s and introducing a sample of experimental weather data collected in Algiers site for a sunny day in summer.

  11. Battery Pack Thermal Design

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, Ahmad

    2016-06-14

    This presentation describes the thermal design of battery packs at the National Renewable Energy Laboratory. A battery thermal management system essential for xEVs for both normal operation during daily driving (achieving life and performance) and off-normal operation during abuse conditions (achieving safety). The battery thermal management system needs to be optimized with the right tools for the lowest cost. Experimental tools such as NREL's isothermal battery calorimeter, thermal imaging, and heat transfer setups are needed. Thermal models and computer-aided engineering tools are useful for robust designs. During abuse conditions, designs should prevent cell-to-cell propagation in a module/pack (i.e., keep the fire small and manageable). NREL's battery ISC device can be used for evaluating the robustness of a module/pack to cell-to-cell propagation.

  12. Research on the characterization and conditioning of uranium mill tailings. II. Thermal stabilization of uranium mill tailings: technical and economic evaluation. Volume 2

    International Nuclear Information System (INIS)

    Dreesen, D.R.; Cokal, E.J.; Thode, E.F.; Wangen, L.E.; Williams, J.M.

    1983-06-01

    A method of conditioning uranium mill tailings has been devised to greatly reduce radon emanation and contaminant leachability by using high-temperature treatments, i.e., thermal stabilization. The thermally stabilized products appear resistant to weathering as measured by the effects of grinding and water leaching. The technical feasibility of the process has been partially verified in pilot-scale experiments. A conceptual thermal stabilization process has been designed and the economics of the process show that the thermal stabilization of tailings can be cost competitive compared with relocation of tailings during remedial action. The alteration of morphology, structure, and composition during thermal treatment would indicate that this stabilization method may be a long-lasting solution to uranium mill tailings disposal problems

  13. Societal acceptance of carbon capture and storage technologies

    International Nuclear Information System (INIS)

    Alphen, Klaas van; Voorst tot Voorst, Quirine van; Hekkert, Marko P.; Smits, Ruud E.H.M.

    2007-01-01

    For the actual implementation of carbon capture and storage (CCS) technologies, societal support is a crucial precondition. This paper describes an extensive study on the acceptance of CCS by stakeholders in the Netherlands and explores one of the determining factors in the acceptance of CCS by the lay public, i.e. the way the Dutch press perceives and portrays CCS. The stakeholder analysis shows that there is a positive attitude towards CCS by industry, government, and environmental NGOs, provided that the conditions they pose on the deployment of CCS are met. The content analysis of Dutch news articles conveys that the media portrayal of CCS is-to a certain extent-a balanced reflection of the way CCS is perceived by the stakeholders. Both analyses show that the concerns about CCS have not overshadowed the main promise that CCS is part of the solution to climate change. However, the current negative aspects of CCS as raised by different stakeholders and the media will remain if no action is taken. Therefore, the conditions posed on the use of CCS, as well as the actions required to meet these conditions, could function as a proxy for the 'societal voice', articulating the most important issues concerning the future acceptance of CCS technology

  14. Unsteady-state human-body exergy consumption rate and its relation to subjective assessment of dynamic thermal environments

    DEFF Research Database (Denmark)

    Schweiker, Marcel; Kolarik, Jakub; Dovjak, Mateja

    2016-01-01

    of the present study confirmed previously indicated trends that lowest human body exergy consumption rate is associated with thermal sensation close to neutrality. Moreover, higher acceptability was in general associated with lower human body exergy consumption rate. (C) 2016 Elsevier B.V. All rights reserved.......Few examples studied applicability of exergy analysis on human thermal comfort. These examples relate the human-body exergy consumption rate with subjectively obtained thermal sensation votes and had been based on steady-state calculation methods. However, humans are rarely exposed to steady...... between the human-body exergy consumption rate and subjective assessment of thermal environment represented by thermal sensation as well as to extend the investigation towards thermal acceptability votes. Comparison of steady-state and unsteady-state model showed that results from both models were...

  15. Modelling LiBr-H2O solution concentration/crystallization of low thermal-powered absorption air conditioning system

    International Nuclear Information System (INIS)

    Abdullah, M.O.

    2000-01-01

    A computer model is developed to predict the concentration of lithium bromide - water (LiBr-H 2 O) solution for used in low thermal energy-driven absorption air conditioning plants design. The computer program is capable to alert the users from undesirable solidification or crystallization zones. Good agreements between simulated concentration and experimental data from standard chart/table have been obtained. (Author)

  16. Measurements of thermal properties of rocks

    International Nuclear Information System (INIS)

    Kumada, Toshiaki

    2001-02-01

    The report concerns the measurement of thermal conductivity and specific heat of supplied sedimental rock B and Funyu rock. The method of measurement of these properties was done with the method which was developed at 1997 and improved much in its accuracy by the present author et al. The porosity of sedimental rock B is 0.55, which is deduced from the density of rock (the porosity deduced from the difference between dry and water filled conditions is 0.42) and the shape and size of pores in rock are much different. Its thermal conductivity is 0.238 W/mK in dry and 1.152 W/mK in water filled conditions respectively, while the thermal conductivity of bentonite is 0.238 W/mK in dry and 1.152 W/mK in water saturated conditions. The difference of thermal conductivity between dry and water saturated conditions is little difference in sedimental rock B and bentonite at same porosity. The porosity of Funyu rock is 0.26 and the shape and size of pores in the rock are uniform. Its thermal conductivity is 0.914 W/mK in dry and 1.405 W/mK in water saturated conditions, while the thermal conductivity of bentonite is 0.606 W/mK in dry and 1.591 W/mK in water saturated conditions respectively. The correlation estimating thermal conductivity of rocks was derived based on Fricke correlation by presuming rocks as a suspension. (author)

  17. Quantifying the Interactions Between Soil Thermal Characteristics, Soil Physical Properties, Hydro-geomorphological Conditions and Vegetation Distribution in an Arctic Watershed

    Science.gov (United States)

    Dafflon, B.; Leger, E.; Robert, Y.; Ulrich, C.; Peterson, J. E.; Soom, F.; Biraud, S.; Tran, A. P.; Hubbard, S. S.

    2017-12-01

    Improving understanding of Arctic ecosystem functioning and parameterization of process-rich hydro-biogeochemical models require advances in quantifying ecosystem properties, from the bedrock to the top of the canopy. In Arctic regions having significant subsurface heterogeneity, understanding the link between soil physical properties (incl. fraction of soil constituents, bedrock depth, permafrost characteristics), thermal behavior, hydrological conditions and landscape properties is particularly challenging yet is critical for predicting the storage and flux of carbon in a changing climate. This study takes place in Seward Peninsula Watersheds near Nome AK and Council AK, which are characterized by an elevation gradient, shallow bedrock, and discontinuous permafrost. To characterize permafrost distribution where the top of permafrost cannot be easily identified with a tile probe (due to rocky soil and/or large thaw layer thickness), we developed a novel technique using vertically resolved thermistor probes to directly sense the temperature regime at multiple depths and locations. These measurements complement electrical imaging, seismic refraction and point-scale data for identification of the various thermal behavior and soil characteristics. Also, we evaluate linkages between the soil physical-thermal properties and the surface properties (hydrological conditions, geomorphic characteristics and vegetation distribution) using UAV-based aerial imaging. Data integration and analysis is supported by numerical approaches that simulate hydrological and thermal processes. Overall, this study enables the identification of watershed structure and the links between various subsurface and landscape properties in representative Arctic watersheds. Results show very distinct trends in vertically resolved soil temperature profiles and strong lateral variations over tens of meters that are linked to zones with various hydrological conditions, soil properties and vegetation

  18. Latitudinal discontinuity in thermal conditions along the nearshore of central-northern Chile.

    Science.gov (United States)

    Tapia, Fabian J; Largier, John L; Castillo, Manuel; Wieters, Evie A; Navarrete, Sergio A

    2014-01-01

    Over the past decade, evidence of abrupt latitudinal changes in the dynamics, structure and genetic variability of intertidal and subtidal benthic communities along central-northern Chile has been found consistently at 30-32°S. Changes in the advective and thermal environment in nearshore waters have been inferred from ecological patterns, since analyses of in situ physical data have thus far been missing. Here we analyze a unique set of shoreline temperature data, gathered over 4-10 years at 15 sites between 28-35°S, and combine it with satellite-derived winds and sea surface temperatures to investigate the latitudinal transition in nearshore oceanographic conditions suggested by recent ecological studies. Our results show a marked transition in thermal conditions at 30-31°S, superimposed on a broad latitudinal trend, and small-scale structures associated with cape-and-bay topography. The seasonal cycle dominated temperature variability throughout the region, but its relative importance decreased abruptly south of 30-31°S, as variability at synoptic and intra-seasonal scales became more important. The response of shoreline temperatures to meridional wind stress also changed abruptly at the transition, leading to a sharp drop in the occurrence of low-temperature waters at northern sites, and a concurrent decrease in corticated algal biomass. Together, these results suggest a limitation of nitrate availability in nearshore waters north of the transition. The localized alongshore change results from the interaction of latitudinal trends (e.g., wind stress, surface warming, inertial period) with a major headland-bay system (Punta Lengua de Vaca at 30.25°S), which juxtaposes a southern stretch of coast characterized by upwelling with a northern stretch of coast characterized by warm surface waters and stratification. This transition likely generates a number of latitude-dependent controls on ecological processes in the nearshore that can explain species

  19. Nevada National Security Site Waste Acceptance Criteria

    International Nuclear Information System (INIS)

    2012-01-01

    This document establishes the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO), Nevada National Security Site Waste Acceptance Criteria (NNSSWAC). The NNSSWAC provides the requirements, terms, and conditions under which the Nevada National Security Site (NNSS) will accept DOE non-radioactive classified waste, DOE non-radioactive hazardous classified waste, DOE low-level radioactive waste (LLW), DOE mixed low-level waste (MLLW), and U.S. Department of Defense (DOD) classified waste for permanent disposal. Classified waste is the only waste accepted for disposal that may be non-radioactive and will be required to meet the waste acceptance criteria for radioactive waste as specified in this document. The NNSA/NSO and support contractors are available to assist you in understanding or interpreting this document. For assistance, please call the NNSA/NSO Waste Management Project (WMP) at (702) 295-7063, and your call will be directed to the appropriate contact.

  20. Nevada National Security Site Waste Acceptance Criteria

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Management

    2012-02-28

    This document establishes the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO), Nevada National Security Site Waste Acceptance Criteria (NNSSWAC). The NNSSWAC provides the requirements, terms, and conditions under which the Nevada National Security Site (NNSS) will accept DOE non-radioactive classified waste, DOE non-radioactive hazardous classified waste, DOE low-level radioactive waste (LLW), DOE mixed low-level waste (MLLW), and U.S. Department of Defense (DOD) classified waste for permanent disposal. Classified waste is the only waste accepted for disposal that may be non-radioactive and will be required to meet the waste acceptance criteria for radioactive waste as specified in this document. The NNSA/NSO and support contractors are available to assist you in understanding or interpreting this document. For assistance, please call the NNSA/NSO Waste Management Project (WMP) at (702) 295-7063, and your call will be directed to the appropriate contact.

  1. Using High-Resolution Hyperspectral and Thermal Airborne Imagery to Assess Physiological Condition in the Context of Wheat Phenotyping

    Directory of Open Access Journals (Sweden)

    Victoria Gonzalez-Dugo

    2015-10-01

    Full Text Available There is a growing need for developing high-throughput tools for crop phenotyping that would increase the rate of genetic improvement. In most cases, the indicators used for this purpose are related with canopy structure (often acquired with RGB cameras and multispectral sensors allowing the calculation of NDVI, but using approaches related with the crop physiology are rare. High-resolution hyperspectral remote sensing imagery provides optical indices related to physiological condition through the quantification of photosynthetic pigment and chlorophyll fluorescence emission. This study demonstrates the use of narrow-band indicators of stress as a potential tool for phenotyping under rainfed conditions using two airborne datasets acquired over a wheat experiment with 150 plots comprising two species and 50 varieties (bread and durum wheat. The flights were performed at the early stem elongation stage and during the milking stage. Physiological measurements made at the time of flights demonstrated that the second flight was made during the terminal stress, known to largely determine final yield under rainfed conditions. The hyperspectral imagery enabled the extraction of thermal, radiance, and reflectance spectra from 260 spectral bands from each plot for the calculation of indices related to photosynthetic pigment absorption in the visible and red-edge regions, the quantification of chlorophyll fluorescence emission, as well as structural indices related to canopy structure. Under the conditions of this study, the structural indices (i.e., NDVI did not show a good performance at predicting yield, probably because of the large effects of terminal water stress. Thermal indices, indices related to chlorophyll fluorescence (calculated using the FLD method, and carotenoids pigment indices (PRI and CAR demonstrated to be better suited for screening complex traits such as crop yield. The study concludes that the indicators derived from high

  2. Evaluation of natural illumination and thermal comfort conditions in the Ribeirao Preto's Technological Village

    Energy Technology Data Exchange (ETDEWEB)

    Basso, A.; Caram, R.M. [Department of Architecture and Urbanism, EESC University of Sao Paulo (USP), Sao Carlos (Brazil)

    2004-07-01

    The results of post-occupancy surveys of the 11 different construction systems used in the dwellings of the Technological Village of Ribeirao Preto, Brazil are analysed. The analyses focus on evaluating the natural illumination and thermal comfort conditions in selected habitation units after 2 years of use. All systems were devised to provide living conditions to low-income families with low purchasing power and, most importantly, to disseminate construction technologies adapted to, and appropriate for, this specific region of the country. The results indicate that the methodology employed is not appropriate using only classical factors to assess the illumination conditions, i.e. illuminance level and daylight factor, for a direct quantification of the illumination. The isolated use of these factors can result in distortions. The evaluation of the environmental conditions is relevant to observe that there can be differences between theoretical thermo-physical properties and actual features of the materials and construction systems analyzed. (author)

  3. Investigation of Heat Pump Operation Strategies with Thermal Storage in Heating Conditions

    Directory of Open Access Journals (Sweden)

    Wangsik Jung

    2017-12-01

    Full Text Available A heat pump with thermal storage system is a system that operates a heat pump during nighttime using inexpensive electricity; during this time, the generated thermal energy is stored in a thermal storage tank. The stored thermal energy is used by the heat pump during daytime. Based on a model of a dual latent thermal storage tank and a heat pump, this study conducts control simulations using both conventional and advanced methods for heating in a building. Conventional methods include the thermal storage priority method and the heat pump priority method, while advanced approaches include the region control method and the dynamic programming method. The heating load required for an office building is identified using TRNSYS (Transient system simulation, used for simulations of various control methods. The thermal storage priority method shows a low coefficient of performance (COP, while the heat pump priority method leads to high electricity costs due to the low use of thermal storage. In contrast, electricity costs are lower for the region control method, which operates using the optimal part load ratio of the heat pump, and for dynamic programming, which operates the system by following the minimum cost path. According to simulation results for the winter season, the electricity costs using the dynamic programming method are 17% and 9% lower than those of the heat pump priority and thermal storage priority methods, respectively. The region control method shows results similar to the dynamic programming method with respect to electricity costs. In conclusion, advanced control methods are proven to have advantages over conventional methods in terms of power consumption and electricity costs.

  4. Thermal Energy Storage for Building Load Management: Application to Electrically Heated Floor

    Directory of Open Access Journals (Sweden)

    Hélène Thieblemont

    2016-07-01

    Full Text Available In cold climates, electrical power demand for space conditioning becomes a critical issue for utility companies during certain periods of the day. Shifting a portion or all of it to off-peak periods can help reduce peak demand and reduce stress on the electrical grid. Sensible thermal energy storage (TES systems, and particularly electrically heated floors (EHF, can store thermal energy in buildings during the off-peak periods and release it during the peak periods while maintaining occupants’ thermal comfort. However, choosing the type of storage system and/or its configuration may be difficult. In this paper, the performance of an EHF for load management is studied. First, a methodology is developed to integrate EHF in TRNSYS program in order to investigate the impact of floor assembly on the EHF performance. Then, the thermal comfort (TC of the night-running EHF is studied. Finally, indicators are defined, allowing the comparison of different EHF. Results show that an EHF is able to shift 84% of building loads to the night while maintaining acceptable TC in cold climate. Moreover, this system is able to provide savings for the customer and supplier if there is a significant difference between off-peak and peak period electricity prices.

  5. Thermal sensation models: a systematic comparison.

    Science.gov (United States)

    Koelblen, B; Psikuta, A; Bogdan, A; Annaheim, S; Rossi, R M

    2017-05-01

    Thermal sensation models, capable of predicting human's perception of thermal surroundings, are commonly used to assess given indoor conditions. These models differ in many aspects, such as the number and type of input conditions, the range of conditions in which the models can be applied, and the complexity of equations. Moreover, the models are associated with various thermal sensation scales. In this study, a systematic comparison of seven existing thermal sensation models has been performed with regard to exposures including various air temperatures, clothing thermal insulation, and metabolic rate values after a careful investigation of the models' range of applicability. Thermo-physiological data needed as input for some of the models were obtained from a mathematical model for human physiological responses. The comparison showed differences between models' predictions for the analyzed conditions, mostly higher than typical intersubject differences in votes. Therefore, it can be concluded that the choice of model strongly influences the assessment of indoor spaces. The issue of comparing different thermal sensation scales has also been discussed. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Relationship of core exit-temperature noise to thermal-hydraulic conditions in PWRs

    International Nuclear Information System (INIS)

    Sweeney, F.J.; Upadhyaya, B.R.

    1983-01-01

    Core exit thermocouple temperature noise and neutron detector noise measurements were performed at the Loss of Fluid Test Facility (LOFT) reactor and a Westinghouse, 1148 MW(e) PWR to relate temperature noise to core thermal-hydraulic conditions. The noise analysis results show that the RMS of the temperature noise increases linearly with increasing core δT at LOFT and the commercial PWR. Out-of-core test loop temperature noise has shown similar behavior. The phase angle between core exit temperature noise and in-core or ex-core neutron noise is directly related to the core coolant flow velocity. However, if the thermocouple response time is slow, compared to the coolant transit time between the sensors, velocities inferred from the phase angle are lower than measured coolant flow velocities

  7. Stress induced conditioning and thermal relaxation in the simulation of quasi-static compression experiments

    International Nuclear Information System (INIS)

    Scalerandi, M; Delsanto, P P; Johnson, P A

    2003-01-01

    Local interaction simulation approach simulations of the ultrasonic wave propagation in multi-grained materials have succeeded in reproducing most of the recently observed nonclassical nonlinear effects, such as stress-strain hysteresis and discrete memory in quasi-static experiments and a downwards shift of the resonance frequency and the generation of odd harmonics at specific amplitude rates in dynamics experiments. By including a simple mechanism of thermally activated random transitions, we can predict the occurrence of experimentally observed effects, such as the conditioning and relaxation of the specimen. Experiments are also suggested for a quantitative assessment of the validity of the model

  8. Stress induced conditioning and thermal relaxation in the simulation of quasi-static compression experiments

    CERN Document Server

    Scalerandi, M; Johnson, P A

    2003-01-01

    Local interaction simulation approach simulations of the ultrasonic wave propagation in multi-grained materials have succeeded in reproducing most of the recently observed nonclassical nonlinear effects, such as stress-strain hysteresis and discrete memory in quasi-static experiments and a downwards shift of the resonance frequency and the generation of odd harmonics at specific amplitude rates in dynamics experiments. By including a simple mechanism of thermally activated random transitions, we can predict the occurrence of experimentally observed effects, such as the conditioning and relaxation of the specimen. Experiments are also suggested for a quantitative assessment of the validity of the model.

  9. Thermal Conductivity of EB-PVD Thermal Barrier Coatings Evaluated by a Steady-State Laser Heat Flux Technique

    Science.gov (United States)

    Zhu, Dongming; Miller, Robert A.; Nagaraj, Ben A.; Bruce, Robert W.

    2000-01-01

    The thermal conductivity of electron beam-physical vapor deposited (EB-PVD) Zr02-8wt%Y2O3 thermal barrier coatings was determined by a steady-state heat flux laser technique. Thermal conductivity change kinetics of the EB-PVD ceramic coatings were also obtained in real time, at high temperatures, under the laser high heat flux, long term test conditions. The thermal conductivity increase due to micro-pore sintering and the decrease due to coating micro-delaminations in the EB-PVD coatings were evaluated for grooved and non-grooved EB-PVD coating systems under isothermal and thermal cycling conditions. The coating failure modes under the high heat flux test conditions were also investigated. The test technique provides a viable means for obtaining coating thermal conductivity data for use in design, development, and life prediction for engine applications.

  10. Genotypic Influence on Aversive Conditioning in Honeybees, Using a Novel Thermal Reinforcement Procedure

    Science.gov (United States)

    Junca, Pierre; Carcaud, Julie; Moulin, Sibyle; Garnery, Lionel; Sandoz, Jean-Christophe

    2014-01-01

    In Pavlovian conditioning, animals learn to associate initially neutral stimuli with positive or negative outcomes, leading to appetitive and aversive learning respectively. The honeybee (Apis mellifera) is a prominent invertebrate model for studying both versions of olfactory learning and for unraveling the influence of genotype. As a queen bee mates with about 15 males, her worker offspring belong to as many, genetically-different patrilines. While the genetic dependency of appetitive learning is well established in bees, it is not the case for aversive learning, as a robust protocol was only developed recently. In the original conditioning of the sting extension response (SER), bees learn to associate an odor (conditioned stimulus - CS) with an electric shock (unconditioned stimulus - US). This US is however not a natural stimulus for bees, which may represent a potential caveat for dissecting the genetics underlying aversive learning. We thus first tested heat as a potential new US for SER conditioning. We show that thermal stimulation of several sensory structures on the bee’s body triggers the SER, in a temperature-dependent manner. Moreover, heat applied to the antennae, mouthparts or legs is an efficient US for SER conditioning. Then, using microsatellite analysis, we analyzed heat sensitivity and aversive learning performances in ten worker patrilines issued from a naturally inseminated queen. We demonstrate a strong influence of genotype on aversive learning, possibly indicating the existence of a genetic determinism of this capacity. Such determinism could be instrumental for efficient task partitioning within the hive. PMID:24828422

  11. Entropy generation method to quantify thermal comfort

    Science.gov (United States)

    Boregowda, S. C.; Tiwari, S. N.; Chaturvedi, S. K.

    2001-01-01

    The present paper presents a thermodynamic approach to assess the quality of human-thermal environment interaction and quantify thermal comfort. The approach involves development of entropy generation term by applying second law of thermodynamics to the combined human-environment system. The entropy generation term combines both human thermal physiological responses and thermal environmental variables to provide an objective measure of thermal comfort. The original concepts and definitions form the basis for establishing the mathematical relationship between thermal comfort and entropy generation term. As a result of logic and deterministic approach, an Objective Thermal Comfort Index (OTCI) is defined and established as a function of entropy generation. In order to verify the entropy-based thermal comfort model, human thermal physiological responses due to changes in ambient conditions are simulated using a well established and validated human thermal model developed at the Institute of Environmental Research of Kansas State University (KSU). The finite element based KSU human thermal computer model is being utilized as a "Computational Environmental Chamber" to conduct series of simulations to examine the human thermal responses to different environmental conditions. The output from the simulation, which include human thermal responses and input data consisting of environmental conditions are fed into the thermal comfort model. Continuous monitoring of thermal comfort in comfortable and extreme environmental conditions is demonstrated. The Objective Thermal Comfort values obtained from the entropy-based model are validated against regression based Predicted Mean Vote (PMV) values. Using the corresponding air temperatures and vapor pressures that were used in the computer simulation in the regression equation generates the PMV values. The preliminary results indicate that the OTCI and PMV values correlate well under ideal conditions. However, an experimental study

  12. Seasonal differences in the subjective assessment of outdoor thermal conditions and the impact of analysis techniques on the obtained results

    Science.gov (United States)

    Kántor, Noémi; Kovács, Attila; Takács, Ágnes

    2016-11-01

    Wide research attention has been paid in the last two decades to the thermal comfort conditions of different outdoor and semi-outdoor urban spaces. Field studies were conducted in a wide range of geographical regions in order to investigate the relationship between the thermal sensation of people and thermal comfort indices. Researchers found that the original threshold values of these indices did not describe precisely the actual thermal sensation patterns of subjects, and they reported neutral temperatures that vary among nations and with time of the year. For that reason, thresholds of some objective indices were rescaled and new thermal comfort categories were defined. This research investigates the outdoor thermal perception patterns of Hungarians regarding the Physiologically Equivalent Temperature ( PET) index, based on more than 5800 questionnaires. The surveys were conducted in the city of Szeged on 78 days in spring, summer, and autumn. Various, frequently applied analysis approaches (simple descriptive technique, regression analysis, and probit models) were adopted to reveal seasonal differences in the thermal assessment of people. Thermal sensitivity and neutral temperatures were found to be significantly different, especially between summer and the two transient seasons. Challenges of international comparison are also emphasized, since the results prove that neutral temperatures obtained through different analysis techniques may be considerably different. The outcomes of this study underline the importance of the development of standard measurement and analysis methodologies in order to make future studies comprehensible, hereby facilitating the broadening of the common scientific knowledge about outdoor thermal comfort.

  13. The Temperature Condition of the Plate with Temperature-Dependent Thermal Conductivity and Energy Release

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    Full Text Available The temperature state of a solid body, in addition to the conditions of its heat exchange with the environment, can greatly depend on the heat release (or heat absorption processes within the body volume. Among the possible causes of these processes should be noted such as a power release in the fuel elements of nuclear reactors, exothermic or endothermic chemical reactions in the solid body material, which respectively involve heat release or absorbtion, heat transfer of a part of the electric power in the current-carrying conductors (so-called Joule’s heat or the energy radiation penetrating into the body of a semitransparent material, etc. The volume power release characterizes an intensity of these processes.The extensive list of references to the theory of heat conductivity of solids offers solutions to problems to determine a stationary (steady over time and non-stationary temperature state of the solids (as a rule, of the canonical form, which act as the sources of volume power release. Thus, in general case, a possibility for changing power release according to the body volume and in solving the nonstationary problems also a possible dependence of this value on the time are taken into consideration.However, in real conditions the volume power release often also depends on the local temperature, and such dependence can be nonlinear. For example, with chemical reactions the intensity of heat release or absorption is in proportion to their rate, which, in turn, is sensitive to the temperature value, and a dependence on the temperature is exponential. A further factor that in such cases makes the analysis of the solid temperature state complicated, is dependence on the temperature and the thermal conductivity of this body material, especially when temperature distribution therein  is significantly non-uniform. Taking into account the influence of these factors requires the mathematical modeling methods, which allow us to build an adequate

  14. Influence of nanoparticle addition on the formation and growth of intermetallic compounds (IMCs) in Cu/Sn–Ag–Cu/Cu solder joint during different thermal conditions

    Science.gov (United States)

    Ting Tan, Ai; Wen Tan, Ai; Yusof, Farazila

    2015-01-01

    Nanocomposite lead-free solders are gaining prominence as replacements for conventional lead-free solders such as Sn–Ag–Cu solder in the electronic packaging industry. They are fabricated by adding nanoparticles such as metallic and ceramic particles into conventional lead-free solder. It is reported that the addition of such nanoparticles could strengthen the solder matrix, refine the intermetallic compounds (IMCs) formed and suppress the growth of IMCs when the joint is subjected to different thermal conditions such as thermal aging and thermal cycling. In this paper, we first review the fundamental studies on the formation and growth of IMCs in lead-free solder joints. Subsequently, we discuss the effect of the addition of nanoparticles on IMC formation and their growth under several thermal conditions. Finally, an outlook on the future growth of research in the fabrication of nanocomposite solder is provided. PMID:27877786

  15. Bridging the Gap between Social Acceptance and Ethical Acceptability.

    Science.gov (United States)

    Taebi, Behnam

    2017-10-01

    New technology brings great benefits, but it can also create new and significant risks. When evaluating those risks in policymaking, there is a tendency to focus on social acceptance. By solely focusing on social acceptance, we could, however, overlook important ethical aspects of technological risk, particularly when we evaluate technologies with transnational and intergenerational risks. I argue that good governance of risky technology requires analyzing both social acceptance and ethical acceptability. Conceptually, these two notions are mostly complementary. Social acceptance studies are not capable of sufficiently capturing all the morally relevant features of risky technologies; ethical analyses do not typically include stakeholders' opinions, and they therefore lack the relevant empirical input for a thorough ethical evaluation. Only when carried out in conjunction are these two types of analysis relevant to national and international governance of risky technology. I discuss the Rawlsian wide reflective equilibrium as a method for marrying social acceptance and ethical acceptability. Although the rationale of my argument is broadly applicable, I will examine the case of multinational nuclear waste repositories in particular. This example will show how ethical issues may be overlooked if we focus only on social acceptance, and will provide a test case for demonstrating how the wide reflective equilibrium can help to bridge the proverbial acceptance-acceptability gap. © 2016 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

  16. Providing better thermal and air quality conditions in school classrooms would be cost-effective

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Wyon, David Peter

    2013-01-01

    codes stipulate that they should be. This is sometimes because financial resources for the maintenance and upgrade of school buildings are inadequate, but it is also because schools are increasingly allowing classroom temperatures to drift above the recommended range of 20–22 °C in warm weather......This paper is an overall summary of research by the authors on how classroom conditions affect the performance of schoolwork by children, motivated by the fact that the thermal and air quality conditions in school classrooms are now almost universally worse than the relevant standards and building...... and allowing outdoor air supply rates to remain so low that carbon dioxide (CO2) levels during school hours exceed 1000 ppm for long periods, in order to conserve energy. The research that is summarized in this paper shows that the indoor environmental consequences of either of these investment-free but ill...

  17. Short-term changes in thermal perception associated with heatwave conditions in Melbourne, Australia

    Science.gov (United States)

    Lam, Cho Kwong Charlie; Gallant, Ailie J. E.; Tapper, Nigel J.

    2018-05-01

    Variations in human thermal perception have been described on timescales from minutes to seasons. However, the effect of weather-related thermal extremes on inter-daily changes to outdoor thermal perception has not been well characterised. This study used human thermal comfort data from an outdoor botanic garden in sub-urban Melbourne, Australia as a case study. We examined inter-daily variations in local visitors' thermal perception before (11-12 January 2014) and after (18-19 January 2014) a severe heatwave from 14 to 17 January 2014, when daily maximum temperature exceeded 41 °C for 4 consecutive days. We compared thermal comfort survey results (pre-heatwave: n = 342, post-heatwave: n = 294) with air temperature and the Universal Thermal Climate Index (UTCI) measurements. Even though the days preceding and following the heatwave had a similar range in temperature (19-25 °C) and UTCI (26-32 °C), the visitors felt cooler in the days following the heatwave (i.e. lower thermal sensation votes). In the 2 days following the heatwave, visitors also wore less clothing compared with before the heatwave. Our results show that the thermal perception of visitors changed significantly following their exposure to the heatwave, even after controlling for changes in clothing choices and the ages of survey participants. Psychological adaptation to heat (such as thermal history and expectation) might be one of the possible explanations for this inter-daily variability of local visitors' thermal perception.

  18. Conditions of Thermal Reclamation Process Realization on a Sample of Spent Moulding Sand from an Aluminum Alloy Foundry Plant

    Directory of Open Access Journals (Sweden)

    Łucarz M.

    2017-06-01

    Full Text Available The results of investigations of thermal reclamation of spent moulding sands originating from an aluminum alloy foundry plant are presented in this paper. Spent sands were crushed by using two methods. Mechanical fragmentation of spent sand chunks was realized in the vibratory reclaimer REGMAS. The crushing process in the mechanical device was performed either with or without additional crushing-grinding elements. The reclaimed material obtained in this way was subjected to thermal reclamations at two different temperatures. It was found that a significant binder gathering on grain surfaces favors its spontaneous burning, even in the case when a temperature lower than required for the efficient thermal reclamation of furan binders is applied in the thermal reclaimer. The burning process, initiated by gas burners in the reclaimer chamber, generates favorable conditions for self-burning (at a determined amount of organic binders on grain surfaces. This process is spontaneously sustained and decreases the demand for gas. However, due to the significant amount of binder, this process is longer than in the case of reclaiming moulding sand prepared with fresh components.

  19. Thermal characteristics of non-edible oils as phase change materials candidate to application of air conditioning chilled water system

    Science.gov (United States)

    Irsyad, M.; Indartono, Y. S.; Suwono, A.; Pasek, A. D.

    2015-09-01

    The addition of phase change material in the secondary refrigerant has been able to reduce the energy consumption of air conditioning systems in chilled water system. This material has a high thermal density because its energy is stored as latent heat. Based on material melting and freezing point, there are several non-edible oils that can be studied as a phase change material candidate for the application of chilled water systems. Forests and plantations in Indonesia have great potential to produce non-edible oil derived from the seeds of the plant, such as; Calophyllum inophyllum, Jatropha curcas L, and Hevea braziliensis. Based on the melting temperature, these oils can further studied to be used as material mixing in the secondary refrigerant. Thermal characteristics are obtained from the testing of T-history, Differential Scanning Calorimetric (DSC) and thermal conductivity materials. Test results showed an increase in the value of the latent heat when mixed with water with the addition of surfactant. Thermal characteristics of each material of the test results are shown completely in discussion section of this article.

  20. Nevada test site waste acceptance criteria

    International Nuclear Information System (INIS)

    1996-01-01

    This document provides the requirements, terms, and conditions under which the Nevada Test Site (NTS) will accept low-level radioactive and mixed waste for disposal; and transuranic and transuranic mixed waste for interim storage at the NTS. Review each section of this document. This document is not intended to include all of the requirements; rather, it is meant as a guide toward meeting the regulations. All references in this document should be observed to avoid omission of requirements on which acceptance or rejection of waste will be based. The Department of Energy/Nevada Operations Office (DOE/NV) and support contractors are available to assist you in understanding or interpreting this document

  1. Nevada test site waste acceptance criteria

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    This document provides the requirements, terms, and conditions under which the Nevada Test Site (NTS) will accept low-level radioactive and mixed waste for disposal; and transuranic and transuranic mixed waste for interim storage at the NTS. Review each section of this document. This document is not intended to include all of the requirements; rather, it is meant as a guide toward meeting the regulations. All references in this document should be observed to avoid omission of requirements on which acceptance or rejection of waste will be based. The Department of Energy/Nevada Operations Office (DOE/NV) and support contractors are available to assist you in understanding or interpreting this document.

  2. A fracture mechanics method of evaluating structural integrity of a reactor vessel due to thermal shock effects following LOCA condition

    International Nuclear Information System (INIS)

    Ramani, D.T.

    1977-01-01

    The importance of knowledge of structural integrity of a reactor vessel due to thermal shock effects, is related to safety and operational requirements in assessing the adequacy and flawless functioing of the nuclear power systems. Followig a loss-of-coolant accident (LOCA) condition the integrity of the reactor vessel due to a sudden thermal shock induced by actuation of emergency core cooling system (ECCS), must be maintained to ensure safe and orderly shutdown of the reactor and its components. The paper encompasses criteria underlaying a fracture mechanics method of analysis to evaluate structural integrity of a typical 950 MWe PWR vessel as a result of very drastic changes in thermal and mechanical stress levels in the reactor vessel wall. The main object of this investigation therefore consists in assessing the capability of a PWR vessel to withstand the most critical thermal shock without inpairing its ability to conserve vital coolant owing to probable crack propagation. (Auth.)

  3. Basic thermal-mechanical properties and thermal shock, fatigue resistance of swaged + rolled potassium doped tungsten

    Science.gov (United States)

    Zhang, Xiaoxin; Yan, Qingzhi; Lang, Shaoting; Xia, Min; Ge, Changchun

    2014-09-01

    The potassium doped tungsten (W-K) grade was achieved via swaging + rolling process. The swaged + rolled W-K alloy exhibited acceptable thermal conductivity of 159.1 W/m K and ductile-to-brittle transition temperature of about 873 K while inferior mechanical properties attributed to the coarse pores and small deformation degree. Then the thermal shock, fatigue resistance of the W-K grade were characterized by an electron beam facility. Thermal shock tests were conducted at absorbed power densities varied from 0.22 to 1.1 GW/m2 in a step of 0.22 GW/m2. The cracking threshold was in the range of 0.44-0.66 GW/m2. Furthermore, recrystallization occurred in the subsurface of the specimens tested at 0.66-1.1 GW/m2 basing on the analysis of microhardness and microstructure. Thermal fatigue tests were performed at 0.44 GW/m2 up to 1000 cycles and no cracks emerged throughout the tests. Moreover, recrystallization occurred after 1000 cycles.

  4. The Effects of Audiovisual Stimulation on the Acceptance of Background Noise.

    Science.gov (United States)

    Plyler, Patrick N; Lang, Rowan; Monroe, Amy L; Gaudiano, Paul

    2015-05-01

    Previous examinations of noise acceptance have been conducted using an auditory stimulus only; however, the effect of visual speech supplementation of the auditory stimulus on acceptance of noise remains limited. The purpose of the present study was to determine the effect of audiovisual stimulation on the acceptance of noise in listeners with normal and impaired hearing. A repeated measures design was utilized. A total of 92 adult participants were recruited for this experiment. Of these participants, 54 were listeners with normal hearing and 38 were listeners with sensorineural hearing impairment. Most comfortable levels and acceptable noise levels (ANL) were obtained using auditory and auditory-visual stimulation modes for the unaided listening condition for each participant and for the aided listening condition for 35 of the participants with impaired hearing that owned hearing aids. Speech reading ability was assessed using the Utley test for each participant. The addition of visual input did not impact the most comfortable level values for listeners in either group; however, visual input improved unaided ANL values for listeners with normal hearing and aided ANL values in listeners with impaired hearing. ANL benefit received from visual speech input was related to the auditory ANL in listeners in each group; however, it was not related to speech reading ability for either listener group in any experimental condition. Visual speech input can significantly impact measures of noise acceptance. The current ANL measure may not accurately reflect acceptance of noise values when in more realistic environments, where the signal of interest is both audible and visible to the listener. American Academy of Audiology.

  5. Analysis of incoloy 800ht alloy tested in thermal transient conditions

    International Nuclear Information System (INIS)

    Velciu, L.; Meleg, T.; Nitu, A.; Popa, L.

    2015-01-01

    This paper investigated Incoloy 800 HT alloy after following thermal transient tests: fast heating rates (50° and 90°C/minute) up to 1,000°C, maintaining this temperature level (0 and 60 minutes), furnace-cooling until 220°C, and then air-cooling. This alloy is one of the candidate materials for construction of the steam generators of the future NPP reactors. The analysis consisted in metallographic examination and traction tests. The samples were investigated using the Olympus GX 71 optical microscope, the OPL microdurometer with automatic cycle and WALTER BAI traction device. The average grain size was determined by linear interception method. The micro hardness was calculated by the relationship from the device technical book. On the traction diagrams were obtained: strength resistance (Rm), elongation at rupture (A) and elastic modulus (E). The tested alloy was compared with the ''as received'' material, and the results showed a good behavior of this alloy in the presented conditions. (authors)

  6. Thermal-hydraulic models for use in simplified reactivity calculations under secondary break conditions

    International Nuclear Information System (INIS)

    Wagner, S.G.; Harris, K.P.; Mansur, J.M.

    1981-01-01

    PWR accident analyses for breaks in the secondary system are characterized by extreme cooling of the core, large inlet temperature gradients, asymmetric stuck control rods and primary coolant flow predictions ranging from a few percent of nominal to full flow. For several years Combustion Engineering has been using the Hermite code to compute reacitvities, power distributions and flow distributions in 3-D for far off nominal thermal-hydraulic and neutronic conditions. These 3-D methods, while costly, have been very successful in analyzing a large class of PWR secondary break accidents. They indicate a much reduced post-scram return-to-power compared to less detailed, bounding core average feedback methods. The availability of a growing number of 3-D calculations has made it possible to develop and benchmark faster running of 2-D methods which account for many of the same effects seen in 3-D. Two such methods are described and evaluated in this paper and one method is shown to be realiable over a wide range of conditions. (orig.) [de

  7. Acceptance of the institutions and the organs of inspection for the nuclear under pressure equipment

    International Nuclear Information System (INIS)

    2006-05-01

    The candidate companies in the acceptance have to justify their competence in inspection on one hand, in nuclear pressure equipment on the other hand. The guide defines the conditions of the acceptance (competence and modes of proof), the contents of the demand of acceptance, the procedure of instruction as well as the conditions of the preservation of the acceptance. The general direction of the nuclear safety and the radiation protection implements the control of the companies and the organs of inspection for their activities in nuclear equipment under pressure. (N.C.)

  8. The Effect of Passive Design Strategies on Thermal Performance of Female Secondary School Buildings during Warm Season in Hot Dry Climate

    Directory of Open Access Journals (Sweden)

    Sahar eZahiri

    2016-03-01

    Full Text Available This paper describes a series of field studies and simulation analysis to improve the thermal performance of school buildings in the city of Tehran in Iran during warm season. The field studies used on-site measurement and questionnaire-based survey in the warm spring season in a typical female secondary school building. The on-site monitoring assessed the indoor air temperature and humidity levels of six classrooms while the occupants completed questionnaires covering their thermal sensations and thermal preferences. Moreover, thermal simulation analysis was also carried out to evaluate and improve the thermal performance of the classrooms based on the students’ thermal requirements and passive design strategies. In this study, the environmental design guidelines for female secondary school buildings were introduced for the hot and dry climate of Tehran, using passive design strategies. The study shows that the application of passive design strategies including south and south-east orientation, 10cm thermal insulation in wall and 5cm in the roof, and the combination of 30cm side fins and overhangs as a solar shading devices, as well as all-day ventilation strategy and the use of thermal mass materials with 25cm-30cm thickness, has considerable impact on indoor air temperatures in warm season in Tehran and keeps the indoor environment in an acceptable thermal condition. The results of the field studies also indicated that most of the occupants found their thermal environment not to be comfortable and the simulation results showed that passive design techniques had a significant influence on the indoor air temperature and can keep it in an acceptable range based on the female students’ thermal requirement. Therefore, in order to enhance the indoor environment and to increase the learning performance of the students, it is necessary to use the appropriate passive design strategies, which also reduce the need for mechanical systems and

  9. Impact of different environmental conditions on lithium-ion batteries performance through the thermal monitoring with fiber sensors

    Science.gov (United States)

    Nascimento, Micael; Ferreira, Marta S.; Pinto, João. L.

    2017-08-01

    In this work, an optical fiber sensing network has been developed to assess the impact of different environmental conditions on lithium batteries performance through the real time thermal monitoring. The battery is submitted to constant current charge and different discharge C-rates, under normal and abusive operating conditions. The results show that for the discharge C-rate of 5.77C, the LiB under cold and dry climates had 32.5% and 27.2% lower temperature variations, when compared with temperate climates, respectively. The higher temperature shift detected in the temperate climate was related to the battery better performance regarding discharge capacity and power capabilities.

  10. Hydromagnetic nonlinear thermally radiative nanoliquid flow with Newtonian heat and mass conditions

    Directory of Open Access Journals (Sweden)

    Muhammad Ijaz Khan

    Full Text Available This paper communicates the analysis of MHD three-dimensional flow of Jeffrey nanoliquid over a stretchable surface. Flow due to a bidirectional surface is considered. Heat and mass transfer subject to volume fraction of nanoparticles, heat generation and nonlinear solar radiation are examined. Newtonian heat and mass transportation conditions are employed at surface. Concept of boundary layer is utilized to developed the mathematical problem. The boundary value problem is dictated by ten physical parameters: Deborah number, Hartman number, ratio of stretching rates, thermophoretic parameter, Brownian motion parameter, Prandtl number, temperature ratio parameter, conjugate heat and mass parameters and Lewis number. Convergent solutions are obtained using homotopic procedure. Convergence zone for obtained results is explicitly identified. The obtained solutions are interpreted physically. Keywords: Hydromagnetic flow, Viscoelastic nanofluid, Thermophoretic and Brownian moment, Nonlinear thermal radiation, Heat generation

  11. Thermal Fatigue Behavior of Air-Plasma Sprayed Thermal Barrier Coating with Bond Coat Species in Cyclic Thermal Exposure

    Directory of Open Access Journals (Sweden)

    Ungyu Paik

    2013-08-01

    Full Text Available The effects of the bond coat species on the delamination or fracture behavior in thermal barrier coatings (TBCs was investigated using the yclic thermal fatigue and thermal-shock tests. The interface microstructures of each TBC showed a good condition without cracking or delamination after flame thermal fatigue (FTF for 1429 cycles. The TBC with the bond coat prepared by the air-plasma spray (APS method showed a good condition at the interface between the top and bond coats after cyclic furnace thermal fatigue (CFTF for 1429 cycles, whereas the TBCs with the bond coats prepared by the high-velocity oxygen fuel (HVOF and low-pressure plasma spray (LPPS methods showed a partial cracking (and/or delamination and a delamination after 780 cycles, respectively. The TBCs with the bond coats prepared by the APS, HVOF and LPPS methods were fully delaminated (>50% after 159, 36, and 46 cycles, respectively, during the thermal-shock tests. The TGO thickness in the TBCs was strongly dependent on the both exposure time and temperature difference tested. The hardness values were found to be increased only after the CFTF, and the TBC with the bond coat prepared by the APS showed the highest adhesive strength before and after the FTF.

  12. Thorium utilisation in thermal reactors

    International Nuclear Information System (INIS)

    Balakrishnan, K.

    1997-01-01

    It is now more or less accepted that the best way to use thorium is in thermal reactors. This is due to the fact that U233 is a good material in the thermal spectrum. Studies of different thorium cycles in various reactor concepts had been carried out in the early days of nuclear power. After three decades of neglect, the world is once again looking at thorium with some interest. We in India have been studying thorium cycles in most of the existing thermal reactor concepts, with greater emphasis on heavy water reactors. In this paper, we report some of the work done in India on different thorium cycles in the Indian pressurized heavy water reactor (PHWR), and also give a description of the design of the advanced heavy water reactor (AHWR). (author). 1 ref., 2 tabs., 5 figs

  13. Thermodynamic study of the effects of ambient air conditions on the thermal performance characteristics of a closed wet cooling tower

    International Nuclear Information System (INIS)

    Papaefthimiou, V.D.; Rogdakis, E.D.; Koronaki, I.P.; Zannis, T.C.

    2012-01-01

    A thermodynamic model was developed and used to assess the sensitivity of thermal performance characteristics of a closed wet cooling tower to inlet air conditions. In the present study, three cases of different ambient conditions are considered: In the first case, the average mid-winter and mid-summer conditions as well as the extreme case of high temperature and relative humidity, in Athens (Greece) during summer are considered according to the Greek Regulation for Buildings Energy Performance. In the second case, the varied inlet air relative humidity while the inlet air dry bulb temperature remains constant were taken into account. In the last case, the effects on cooling tower thermal behaviour when the inlet air wet bulb temperature remains constant were examined. The proposed model is capable of predicting the variation of air thermodynamic properties, sprayed water and serpentine water temperature inside the closed wet cooling tower along its height. The reliability of simulations was tested against experimental data, which were obtained from literature. Thus, the proposed model could be used for the design of industrial and domestic applications of conventional air-conditioning systems as well as for sorption cooling systems with solid and liquid desiccants where closed wet cooling towers are used for precooling the liquid solutions. The most important result of this theoretical investigation is that the highest fall of serpentine water temperature and losses of sprayed water are observed for the lowest value of inlet wet bulb temperature. Hence, the thermal effectiveness, which is associated with the temperature reduction of serpentine water as well as the operational cost, which is related to the sprayed water loss due to evaporation, of a closed wet cooling tower depend predominantly on the degree of saturation of inlet air.

  14. Den betingede accept

    DEFF Research Database (Denmark)

    Kolind, Torsten

    1999-01-01

    The article focus on aspects of identity and social order in relation to the interaction between ‘normals' and ex-prisoners, that is, ex-prisoners, who wants to live a normal life without criminality. It is argued, that this interaction and the normality that the ex-prisoner is granted often......, on the surface, can look rather unproblematic, but that it, none the less, is ruled by, what the author calls the conditioned accept. That is, the ex-prisoner should see himself as normal, at the same time that he withdraw from those situations, practices and attitude where the normals would have difficulties...

  15. Palmitic acid/polypyrrole composites as form-stable phase change materials for thermal energy storage

    International Nuclear Information System (INIS)

    Silakhori, Mahyar; Metselaar, Hendrik Simon Cornelis; Mahlia, Teuku Meurah Indra; Fauzi, Hadi; Baradaran, Saeid; Naghavi, Mohammad Sajad

    2014-01-01

    Highlights: • A novel phase change composite of palmitic acid–polypyrrole(PA–PPy) was fabricated. • Thermal properties of PA–PPy are characterized in different mass ratios of PA–PPy. • Thermal cycling test showed that form stable PCM had a favorable thermal reliability. - Abstract: In this study a novel palmitic acid (PA)/polypyrrole (PPy) form-stable PCMs were readily prepared by in situ polymerization method. PA was used as thermal energy storage material and PPy was operated as supporting material. Form-stable PCMs were investigated by SEM (scanning electron microscopy) and FTIR (Fourier transform infrared spectrometer) analysis that illustrated PA Particles were wrapped by PPy particles. XRD (X-ray diffractometer) was used for crystalline phase of PA/PPy composites. Thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC) were used for investigating Thermal stability and thermal energy storage properties of prepared form-stable PCMs. According to the obtained results the form stable PCMs exhibited favorable thermal stability in terms of their phase change temperature. The form-stable PCMs (79.9 wt% loading of PA) were considered as the highest loading PCM with desirable latent heat storage of 166.3 J/g and good thermal stability. Accelerated thermal cycling tests also showed that form stable PCM had an acceptable thermal reliability. As a consequence of acceptable thermal properties, thermal stability and chemical stability, we can consider the new kind of form stable PCMs for low temperature solar thermal energy storage applications

  16. A computational model for thermal fluid design analysis of nuclear thermal rockets

    International Nuclear Information System (INIS)

    Given, J.A.; Anghaie, S.

    1997-01-01

    A computational model for simulation and design analysis of nuclear thermal propulsion systems has been developed. The model simulates a full-topping expander cycle engine system and the thermofluid dynamics of the core coolant flow, accounting for the real gas properties of the hydrogen propellant/coolant throughout the system. Core thermofluid studies reveal that near-wall heat transfer models currently available may not be applicable to conditions encountered within some nuclear rocket cores. Additionally, the possibility of a core thermal fluid instability at low mass fluxes and the effects of the core power distribution are investigated. Results indicate that for tubular core coolant channels, thermal fluid instability is not an issue within the possible range of operating conditions in these systems. Findings also show the advantages of having a nonflat centrally peaking axial core power profile from a fluid dynamic standpoint. The effects of rocket operating conditions on system performance are also investigated. Results show that high temperature and low pressure operation is limited by core structural considerations, while low temperature and high pressure operation is limited by system performance constraints. The utility of these programs for finding these operational limits, optimum operating conditions, and thermal fluid effects is demonstrated

  17. Effects of thermal efficiency in DCMD and the preparation of membranes with low thermal conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhehao, E-mail: ccgri_lzh@163.com [Changchun Gold Research Institute, 130012 (China); Peng, Yuelian, E-mail: pyl@live.com.au [Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Dong, Yajun; Fan, Hongwei [Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Chen, Ping [The Research Institute of Environmental Protection, North China Pharmaceutical Group Corporation, 050015 (China); Qiu, Lin [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Jiang, Qi [National Major Science and Technology Program Management Office for Water Pollution Control and Treatment, MEP, 100029 (China)

    2014-10-30

    Highlights: • The effects on vapor flux and thermal efficiency were simulated. • The conditions favoring vapor flux also favored thermal efficiency. • Four microporous polymer membranes were compared. • The SiO{sub 2} aerogel coating reduced the thermal conductivity of polymer membranes. • A 3ω technique was used to measure the thermal conductivity of membranes. - Abstract: The effects of the membrane characteristics and operational conditions on the vapor flux and thermal efficiency in a direct contact membrane distillation (DCMD) process were studied with a mathematical simulation. The membrane temperature, driving force of vapor transfer, membrane distillation coefficient, etc. were used to analyze the effects. The operating conditions that increased the vapor flux improved the thermal efficiency. The membrane characteristics of four microporous membranes and their performances in DCMD were compared. A polysulfone (PSf) membrane prepared via vapor-induced phase separation exhibited the lowest thermal conductivity. The PSf and polyvinylidene difluoride (PVDF) membranes were modified using SiO{sub 2} aerogel blending and coating to reduce the thermal conductivity of the membrane. The coating process was more effective than the blending process toward this end. The changes in the structure of the modified membrane were observed with a scanning electron microscope. Si was found on the modified membrane surface with an energy spectrometer. The PVDF composite and support membranes were tested during the DCMD process; the composite membrane had a higher vapor flux and a better thermal efficiency than the support. A new method based on a 3ω technique was used to measure the thermal conductivity of the membranes.

  18. Effects of thermal efficiency in DCMD and the preparation of membranes with low thermal conductivity

    International Nuclear Information System (INIS)

    Li, Zhehao; Peng, Yuelian; Dong, Yajun; Fan, Hongwei; Chen, Ping; Qiu, Lin; Jiang, Qi

    2014-01-01

    Highlights: • The effects on vapor flux and thermal efficiency were simulated. • The conditions favoring vapor flux also favored thermal efficiency. • Four microporous polymer membranes were compared. • The SiO 2 aerogel coating reduced the thermal conductivity of polymer membranes. • A 3ω technique was used to measure the thermal conductivity of membranes. - Abstract: The effects of the membrane characteristics and operational conditions on the vapor flux and thermal efficiency in a direct contact membrane distillation (DCMD) process were studied with a mathematical simulation. The membrane temperature, driving force of vapor transfer, membrane distillation coefficient, etc. were used to analyze the effects. The operating conditions that increased the vapor flux improved the thermal efficiency. The membrane characteristics of four microporous membranes and their performances in DCMD were compared. A polysulfone (PSf) membrane prepared via vapor-induced phase separation exhibited the lowest thermal conductivity. The PSf and polyvinylidene difluoride (PVDF) membranes were modified using SiO 2 aerogel blending and coating to reduce the thermal conductivity of the membrane. The coating process was more effective than the blending process toward this end. The changes in the structure of the modified membrane were observed with a scanning electron microscope. Si was found on the modified membrane surface with an energy spectrometer. The PVDF composite and support membranes were tested during the DCMD process; the composite membrane had a higher vapor flux and a better thermal efficiency than the support. A new method based on a 3ω technique was used to measure the thermal conductivity of the membranes

  19. Investigation of stress in a circular tunnel due to overburden and thermal loading of horizontally placed 21 PWR multi purpose canisters

    International Nuclear Information System (INIS)

    Kandalaft-Ladkany, N.; Wyman, R.V.

    1994-01-01

    The drift of a High Level Nuclear Waste (HLNW) Repository were subjected to 2-D thermal loading resulting from the horizontal emplacement of 125 Ton Multi-Purpose Canisters (MPC). Ten 2-D temperature profiles, resulting from 57 Kw/acre and 114 Kw/acre thermal loading conditions, were used in a finite element analysis of the drift; in which a quadrant of the drift and surrounding rock ±100m above and below the drift were modeled. Our analysis shows that the 114 Kw/acre thermal loading results in compressive stresses around the drift, 60 years after emplacement, that exceed the unconfined compressive strength of the TSW tuff analyzed. Stresses resulting from a 57 Kw/acre thermal loading are within the acceptable limit in tunnel rock. A parametric analysis of the invert backfill material showed that Young's modulus for the invert backfill should closely match that of the surrounding unconfined rock in the tunnel in order to prevent an unacceptable stress rise in both rock and backfill

  20. Wireless smart meters and public acceptance: the environment, limited choices, and precautionary politics.

    Science.gov (United States)

    Hess, David J; Coley, Jonathan S

    2014-08-01

    Wireless smart meters (WSMs) promise numerous environmental benefits, but they have been installed without full consideration of public acceptance issues. Although societal-implications research and regulatory policy have focused on privacy, security, and accuracy issues, our research indicates that health concerns have played an important role in the public policy debates that have emerged in California. Regulatory bodies do not recognize non-thermal health effects for non-ionizing electromagnetic radiation, but both homeowners and counter-experts have contested the official assurances that WSMs pose no health risks. Similarities and differences with the existing social science literature on mobile phone masts are discussed, as are the broader political implications of framing an alternative policy based on an opt-out choice. The research suggests conditions under which health-oriented precautionary politics can be particularly effective, namely, if there is a mandatory technology, a network of counter-experts, and a broader context of democratic contestation.

  1. Indoor Air Quality and Thermal Comfort in School Buildings

    Science.gov (United States)

    Juhásová Šenitková, Ingrid

    2017-12-01

    This paper presents results to thermal comfort and environment quality questions in 21 school building rooms. Results show that about 80% of the occupants expressed satisfaction with their thermal comfort in only 11% of the buildings surveyed. Air quality scores were somewhat higher, with 26% of buildings having 80% or occupant satisfaction. With respect to thermal comfort and air quality performance goals set out by standards, most buildings appear to be falling far short. Occupant surveys offer a means to systematically measure this performance, and also to provide diagnostic information for building designers and operators. The odours from building materials as well as human odours were studied by field measurement. The odour intensity and indoor air acceptability were assessed by a sensory panel. The concentrations of total volatile organic compounds and carbon dioxide were measured. The odours from occupancy and building materials were studied under different air change rate. The case study of indoor air acceptability concerning to indoor odours and its effect on perceived air quality are also presented in this paper.

  2. Thermal Analysis of a Power Conditioning Unit for a Howitzer

    Science.gov (United States)

    2009-08-01

    contact resistance Interface ( mA2 -K / W) AL-PCB 0.000389 AL-AL (thermal grease) 0.000083 AL-power chips 0.003891 AL-power chips (thermal grease...1120 W/ mA2 . Figure 3 shows the view of the box that the source of the solar radiation sees. The inside of the box is cluttered with cables, wiring, and...temperature (130°F) and a conservative convective heat transfer coefficient (5 W/ mA2 ) to all of the outer surfaces. These outer surfaces would

  3. Underground Coal Thermal Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P. [Univ. of Utah, Salt Lake City, UT (United States); Deo, M. [Univ. of Utah, Salt Lake City, UT (United States); Eddings, E. [Univ. of Utah, Salt Lake City, UT (United States); Sarofim, A. [Univ. of Utah, Salt Lake City, UT (United States); Gueishen, K. [Univ. of Utah, Salt Lake City, UT (United States); Hradisky, M. [Univ. of Utah, Salt Lake City, UT (United States); Kelly, K. [Univ. of Utah, Salt Lake City, UT (United States); Mandalaparty, P. [Univ. of Utah, Salt Lake City, UT (United States); Zhang, H. [Univ. of Utah, Salt Lake City, UT (United States)

    2012-01-11

    The long-term objective of this work is to develop a transformational energy production technology by insitu thermal treatment of a coal seam for the production of substitute natural gas (SNG) while leaving much of the coal's carbon in the ground. This process converts coal to a high-efficiency, low-GHG emitting gas fuel. It holds the potential of providing environmentally acceptable access to previously unusable coal resources. This topical report discusses the development of experimental capabilities, the collection of available data, and the development of simulation tools to obtain process thermo-chemical and geo-thermal parameters in preparation for the eventual demonstration in a coal seam. It also includes experimental and modeling studies of CO2 sequestration.

  4. Impact of an acceptance facilitating intervention on diabetes patients' acceptance of Internet-based interventions for depression: a randomized controlled trial.

    Science.gov (United States)

    Baumeister, H; Nowoczin, L; Lin, J; Seifferth, H; Seufert, J; Laubner, K; Ebert, D D

    2014-07-01

    To (1) determine diabetes patients' acceptance of Internet-based interventions (IBIs) for depression, to (2) examine the effectiveness of an acceptance facilitating intervention (AFI) and to (3) explore subgroup specific effects. 141 diabetes patients from two inpatient rehabilitation units and one outpatient clinic in Germany were randomly allocated to an intervention (IG) and a no-intervention control group (CG). The IG received an AFI consisting of a personal information session before filling-out a questionnaire on patients' acceptance of IBIs, predictors of acceptance (performance expectancy, effort expectancy, social influence, facilitating conditions, and Internet anxiety) as well as sociodemographic, depression-related and diabetes-related variables. The CG filled out the questionnaire immediately. Patients' acceptance of IBIs was measured with a four-item scale (sum-score ranging from 4 to 20). The CG showed a low (50.7%) to medium (40.8%) acceptance with only 8.5% of all diabetes patients reporting a high acceptance of IBIs for depression. The AFI had no significant effect on acceptance (IG: M=10.55, SD=4.69, n=70; KG: M=9.65, SD=4.27, n=71; d=0.20 [95%-CI: -0.13;0.53]) and the predictors of acceptance. Yet, subgroup analyses yielded a trend for depressed, diabetes-related distressed, female and younger (Internet to profit from the AFI. Diabetes patients show a rather low acceptance toward IBIs for depression. Findings indicate that the AFI is likely to be effective in the subgroup of depressed, diabetes-related distressed, female or younger diabetes patients, but not in the whole target population. Hence, AFIs might need to be tailored to the specific needs of subpopulations. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. Effect of the Evaporative Cooling on the Human Thermal Comfort and Heat Stress in a Greenhouse under Arid Conditions

    Directory of Open Access Journals (Sweden)

    A. M. Abdel-Ghany

    2013-01-01

    Full Text Available Thermal sensation and heat stress were evaluated in a plastic greenhouse, with and without evaporative cooling, under arid climatic conditions in Riyadh, Saudi Arabia. Suitable thermal comfort and heat stress scales were selected for the evaluation. Experiments were conducted in hot sunny days to measure the required parameters (i.e., the dry and wet bulb temperatures, globe temperature, natural wet bulb temperature, and solar radiation flux in the greenhouse. The results showed that in the uncooled greenhouse, workers are exposed to strong heat stress and would feel very hot most of the day time; they are safe from heat stress risk and would feel comfortable during night. An efficient evaporative cooling is necessary during the day to reduce heat stress and to improve the comfort conditions and is not necessary at night. In the cooled greenhouse, workers can do any activity: except at around noon they should follow a proposed working schedule, in which the different types of work were scheduled along the daytimes based on the heat stress value. To avoid heat stress and to provide comfort conditions in the greenhouses, the optimum ranges of relative humidity and air temperature are 48–55% and 24–28°C, respectively.

  6. Behaviour at landfills of waste having undergone mechanic-biological and thermal conditioning; Deponieverhalten mechanisch-biologisch und thermisch behandelten Restabfalls

    Energy Technology Data Exchange (ETDEWEB)

    Danhamer, H.; Dach, J.; Jager, J. [Institut WAR, Darmstadt (Germany). FG Abfalltechnik

    1998-12-31

    The work studies, in landfill test reactors, water, gas and heat transport as well as gas and leachate formation in waste having undergone mechanical-biological and thermal conditioning. (orig.) [Deutsch] Es wurde der Wasser-, Gas- und Waermetransport, sowie die Gasbildung- und Sickerwasserbelastung mechanisch-biologisch und thermisch vorbehandelter Abfaelle in Deponieversuchsreaktoren untersucht. (orig.)

  7. A Study of Demand Response Effect of Thermal Storage Air-Conditioning Systems in Consideration of Electricity Market Prices

    Science.gov (United States)

    Omagari, Yuko; Sugihara, Hideharu; Tsuji, Kiichiro

    This paper evaluates the economic impact of the introduction of customer-owned Thermal Storage Air-conditioning (TSA) systems, in an electricity market, from the viewpoint of the load service entity. We perform simulations on the condition that several thousand customers install TSA systems and shift peak demand in an electricity market by one percent. Our numerical results indicate that the purchase cost of the LSE was reduced through load management of customers with TSA systems. The introduction of TSA systems also reduced the volatility of market clearing price and reduced the whole-trade cost in an electricity market.

  8. Challenging the assumptions for thermal sensation scales

    DEFF Research Database (Denmark)

    Schweiker, Marcel; Fuchs, Xaver; Becker, Susanne

    2016-01-01

    Scales are widely used to assess the personal experience of thermal conditions in built environments. Most commonly, thermal sensation is assessed, mainly to determine whether a particular thermal condition is comfortable for individuals. A seven-point thermal sensation scale has been used...... extensively, which is suitable for describing a one-dimensional relationship between physical parameters of indoor environments and subjective thermal sensation. However, human thermal comfort is not merely a physiological but also a psychological phenomenon. Thus, it should be investigated how scales for its...... assessment could benefit from a multidimensional conceptualization. The common assumptions related to the usage of thermal sensation scales are challenged, empirically supported by two analyses. These analyses show that the relationship between temperature and subjective thermal sensation is non...

  9. Guide to Setting Thermal Comfort Criteria and Minimizing Energy Use in Delivering Thermal Comfort

    Energy Technology Data Exchange (ETDEWEB)

    Regnier, Cindy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-08-01

    Historically thermal comfort in buildings has been controlled by simple dry bulb temperature settings. As we move into more sophisticated low energy building systems that make use of alternate systems such as natural ventilation, mixed mode system and radiant thermal conditioning strategies, a more complete understanding of human comfort is needed for both design and control. This guide will support building designers, owners, operators and other stakeholders in defining quantifiable thermal comfort parameters?these can be used to support design, energy analysis and the evaluation of the thermal comfort benefits of design strategies. This guide also contains information that building owners and operators will find helpful for understanding the core concepts of thermal comfort. Whether for one building, or for a portfolio of buildings, this guide will also assist owners and designers in how to identify the mechanisms of thermal comfort and space conditioning strategies most important for their building and climate, and provide guidance towards low energy design options and operations that can successfully address thermal comfort. An example of low energy design options for thermal comfort is presented in some detail for cooling, while the fundamentals to follow a similar approach for heating are presented.

  10. Macro- and microclimate conditions may alter grapevine deacclimation: variation in thermal amplitude in two contrasting wine regions from North and South America

    Science.gov (United States)

    Antivilo, Francisco Gonzalez; Paz, Rosalía Cristina; Keller, Markus; Borgo, Roberto; Tognetti, Jorge; Juñent, Fidel Roig

    2017-12-01

    Low temperature is a limiting factor that affects vineyard distribution globally. The level of cold hardiness acquired during the dormant season by Vitis sp. is crucial for winter survival. Most research published on this topic has been generated beyond 40° N latitude, where daily mean temperatures may attain injurious levels during the dormant season resulting in significant damage to vines and buds. Symptoms of cold injury have been identified in Mendoza (32-35° S latitude), a Southern Hemisphere wine region characterized by a high thermal amplitude, and warm winds during the dormant season. These symptoms have usually been attributed to drought and/or pathogens, but not to rapid deacclimation followed by injurious low temperatures. Because local information on meteorological events as probable causes is scarce, this research was designed to test and study this assumption by comparing macro-, meso-, and microclimatic data from Mendoza, Argentina, and eastern Washington, USA. The goal was to unveil why freezing damage has occurred in both regions, despite the existence of large climatic differences. Because environmental parameters under field conditions may not correspond to data recorded by conventional weather stations, sensors were installed in vineyards for comparison. Microclimatic conditions on grapevines were also evaluated to assess the most vulnerable portions of field-grown grapevines. In order to better understand if it may be possible to modify cold hardiness status in a short period with high thermal amplitude conditions, deacclimation was induced using a thermal treatment. Hence, despite the fact that Mendoza is warmer, and temperatures are not as extreme as in Washington, high daily thermal amplitude might be partially involved in plant deacclimation, leading to a differential cold hardiness response.

  11. Thermal, physiological strain index and perceptual responses in Iranian Muslim women under Thermal Condition in order to Guide in Prevention of Heat Stress

    Directory of Open Access Journals (Sweden)

    Peymaneh Habibi

    2014-09-01

    Full Text Available Heat stress risk assessment, as a harmful agent at workplace, is essential for controlling heat strain. The purpose of this study was relation between physiological and perceptual heat strain responses in Iranian veiled women under laboratory thermal conditions. This experimental study was carried out on 36 healthy females (age 22.3 ± 2.0 yr, height 162.76±5. 57cm, weight 55.82 ± 9.27kg in sitting state under thermal conditions (27 - 38° C in the hot-dry climatic condition for 120 min. In order to calculate the physiological strain index (PSI, oral temperature and heart rate were measured every 5 min. Physiological factors, and Heat Strain Score Index (HSSI questionnaires are simultaneous measurements taken at any 5 min during the exposure and physiological factors, and Heat Strain Score Index (HSSI questionnaires are the initial measurements. The data were analyzed using correlation and line regression by test spss16. The results showed that the average heart rate and oral temperature at resting and sitting were between 83.06 ±9.41bpm, 87.91 ±7.87 bpm and 36.7° C, 37. 1° C respectively. Also, the results have revealed a direct and significant and direct correlation among HSSI with WBGT (R2 = 0.97, P< 0.001, PSI (R2 = 0.96, P< 0.001, oral temperature (R2 = 0.96, P< 0.001 and heart rate (R2 = 0.62, P< 0.01 indices. The results have shown that simultaneously with the increase in valid indices of heat stress evaluation such as WBGT and PSI indices, the amount of HSSI index has also increased with high power. Therefore, it can be conclude that when there is no access to a reliable heat stress method such as WBGT or PSI indices, HSSI index, an objective and subjective heat strain method, can be used as a simple, fast and inexpensive method for evaluating the heat strain in women.

  12. Acceptance criteria for radioactive waste deposition

    International Nuclear Information System (INIS)

    Rzyski, B.M.

    1989-01-01

    The disposal of low-and intermediate level radioactive waste in either shallow ground or rock cavities must be subjected to special guidelines which are used by national authorities and implementing bodies when establishing and regulating respositories. These informations are given by the acceptance criteria and will depend on specific site conditions and optmized procedures. (author) [pt

  13. The assessment of the impact of socio-economic factors in accepting cancer using the Acceptance of Illness Scale (AIS).

    Science.gov (United States)

    Czerw, Aleksandra I; Bilińska, Magdalena; Deptała, Andrzej

    2016-01-01

    The paper presents the results of examining the level of acceptance of the illness in cancer patients using the Acceptance of Illness Scale (AIS). The study involved cancer patients treated at the Central Clinical Hospital of the Ministry the Interior in Warsaw in 2014. The questionnaire comprised basic demographic questions (socio-economic factors) and the AIS test estimating the level of illness acceptance in patients. For the group of patients in the research group, the arithmetic mean amounted to 27.56 points. The period of time that elapsed between the first cancer diagnosis and the start of the study did not influence the score of accepting illness. The acceptance of illness in patients diagnosed with metastases differed from the acceptance of illness by patients diagnosed with metastatic cancer. Females obtained the average of 29.59 in the AIS test, whereas the average in male patients was 26.17. The patients' age did not impact the AIS test. There were no differences in the AIS test results between a group of people with secondary education and a group of people with higher education. There were no differences in the AIS test results between employed individuals versus pensioners. The inhabitants of cities were characterized by the highest degree of acceptance of their health condition. The lowest degree of acceptance of illness was observed in the group with the lowest average incomes. In the group of married individuals the average degree of acceptance of illness amounted to 27.37 points. The average degree of acceptance of illness in patients that declared themselves as single amounted to 25.75. The average degree of acceptance of illness in the study group was 27.56 points, which is a relatively high level of acceptance of cancer. The main socio-economic factor, which influenced the AIS test results was whether metastases were diagnosed or not. There were no differences between patients in groups where the time that elapsed from the first diagnosis of

  14. The assessment of the impact of socio-economic factors in accepting cancer using the Acceptance of Illness Scale (AIS

    Directory of Open Access Journals (Sweden)

    Aleksandra I. Czerw

    2015-11-01

    Full Text Available Aim of the study : The paper presents the results of examining the level of acceptance of the illness in cancer patients using the Acceptance of Illness Scale (AIS. Materials and methods: The study involved cancer patients treated at the Central Clinical Hospital of the Ministry the Interior in Warsaw in 2014. The questionnaire comprised basic demographic questions (socio-economic factors and the AIS test estimating the level of illness acceptance in patients. Results : For the group of patients in the research group, the arithmetic mean amounted to 27.56 points. The period of time that elapsed between the first cancer diagnosis and the start of the study did not influence the score of accepting illness. The acceptance of illness in patients diagnosed with metastases differed from the acceptance of illness by patients diagnosed with metastatic cancer. Females obtained the average of 29.59 in the AIS test, whereas the average in male patients was 26.17. The patients’ age did not impact the AIS test. There were no differences in the AIS test results between a group of people with secondary education and a group of people with higher education. There were no differences in the AIS test results between employed individuals versus pensioners. The inhabitants of cities were characterized by the highest degree of acceptance of their health condition. The lowest degree of acceptance of illness was observed in the group with the lowest average incomes. In the group of married individuals the average degree of acceptance of illness amounted to 27.37 points. The average degree of acceptance of illness in patients that declared themselves as single amounted to 25.75. Conclusions : The average degree of acceptance of illness in the study group was 27.56 points, which is a relatively high level of acceptance of cancer. The main socio-economic factor, which influenced the AIS test results was whether metastases were diagnosed or not. There were no

  15. Waste acceptance and impact ON D and D in Switzerland

    International Nuclear Information System (INIS)

    Maxeiner, Harald

    2002-01-01

    Harald Maxeiner described clearance and waste conditioning requirements in Switzerland, and their impacts on decommissioning: Although decommissioning of the first (oldest) reactor will not take place until 2009 at the earliest (hypothetical operating lifetime of 40 years), detailed decommissioning studies have to be carried out today, in order to demonstrate the feasibility of the technologies to be used and to determine anticipated costs (for the purpose of calculating financial contributions to a decommissioning fund). The studies are based on waste acceptance criteria and guidelines that apply to waste already in existence. The focus is on preparing inventories of activated and contaminated components and conditioning of these components. The basis for present and future conditioning of radioactive wastes, as well as for their interim storage and final disposal, is provided by the official guideline HSK R-14. According to this guideline, raw waste requires to be solidified (inter alia with cement) and the resulting waste product must: remain intact until final disposal, not be readily dispersible, be resistant to aqueous media, not be readily combustible, not contain any unnecessary voids, contain as little organic material as possible. The waste package containing the waste product must: constitute a further barrier to dispersion, outlast (at least) interim storage, be documented with details of manufacturing, composition, properties, be designed to resist corrosion using suitable materials, be characterised by a quality assurance program for raw waste, waste product and waste package. The only possible reasons for interim storage of waste without solidification are: decay storage followed by conventional waste management, if waste packages fulfil acceptance criteria for the final repository without further treatment, if, in the foreseeable future, an alternative conditioning method can be expected. The guidelines and acceptance criteria mentioned set strict

  16. Providing thermal-hydraulic boundary conditions to the reactor code TINTE through a Flownex-TINTE coupling - HTR2008-58110

    International Nuclear Information System (INIS)

    Marais, D.; Greyvenstein, G. P.

    2008-01-01

    TINTE is a well established reactor analysis code which models the transient behaviour of pebble bed reactor cores but it does not include the capabilities to model a power conversion unit (PCU). This raises the issue that TINTE cannot model full system transients. One way to overcome this problem is to supply TINTE with time-dependant thermal-hydraulic boundary conditions which are obtained from PCU simulations. This study investigates a method to provide boundary conditions for the nuclear code TINTE during full system transients. This was accomplished by creating a high level interface between the systems CFD code Flownex and TINTE. An indirect coupling method is explored whereby characteristics of the PCU are matched to characteristics of the nuclear core. This method eliminates the need to iterate between the two codes. A number of transients are simulated using the coupled code and then compared against stand-alone Flownex simulations. The coupling method introduces relatively small errors when reproducing mass flow, temperature and pressure in steady state analysis, but become more pronounced when dealing with fast thermal-hydraulic transients. Decreasing the maximum time step length of TINTE reduces this problem, but increases the computational time. Copyright ASME 2008. (authors)

  17. Diffusion Mechanisms and Lattice Locations of Thermal-Equilibrium Defects in Si-Ge Alloys

    CERN Multimedia

    Lyutovich, K; Touboltsev, V; Laitinen, P O; Strohm, A

    2002-01-01

    It is generally accepted that Ge and Si differ considerably with respect to intrinsic-point-defect-mediated diffusion. In Ge, the native point defects dominating under thermal-equilibium conditions at all solid-state temperatures accessible in diffusion experiments are vacancies, and therefore Ge self-diffusion is vacancy-controlled. In Si, by contrast, self-interstitials and vacancies co-exist in thermal equilibrium. Whereas in the most thoroughly investigated temperature regime above about 1000$^\\circ$C Si self-diffusion is self-interstitial-controlled, it is vacancy-controlled at lower temperatures. According to the scenario displayed above, self-diffusion in Si-Ge alloys is expected to change from an interstitialcy mechanism on the Si side to a vacancy mechanism on the Ge side. Therefore, $^{71}$Ge self-diffusion experiments in Si$_{1- \\it y}$Ge$_{\\it y}$ as a function of composition Y are highly interesting. In a first series of experiments the diffusion of Ge in 0.4 to 10 $\\mu$m thick, relaxed, low-disl...

  18. Evaluative conditioning of food technologies

    DEFF Research Database (Denmark)

    Loebnitz, Natascha; Grunert, Klaus G

    2015-01-01

    Consumer attitudes play an important role in the acceptance of new technologies. The success of food innovations depends on understanding how consumers form and change attitudes toward food technologies. Earlier post hoc explanations suggest that evaluative conditioning can change consumer...... attitudes toward food technologies. The present study tests how evaluative conditioning can affect consumer acceptance of new food technologies. Furthermore, authors investigate whether evaluative conditioning is resistant to extinction after a two-month period and whether the evaluative conditioning effect...... prevails in a product-related context. Within an evaluative conditioning paradigm including between-subjects control groups in addition to standard within-subjects control conditions, participants were presented with three food technologies (conventional, enzyme, and genetic technology) paired...

  19. The social acceptance of artificial photosynthesis: towards a conceptual framework

    Science.gov (United States)

    Sovacool, Benjamin K.; Gross, Allan

    2015-01-01

    Advancements in artificial photosynthesis have the potential to radically transform how societies convert and use energy. Their successful development, however, hinges not only on technical breakthroughs, but also acceptance and adoption by energy users. This article introduces a conceptual framework enabling analysts, planners and even investors to determine environments where artificial photosynthesis may thrive, and those where it may struggle. Drawn from work looking at the barriers and acceptance of solar photovoltaic and wind energy systems, the article proposes that social acceptance has multiple dimensions—socio-political, community and market—that must be met holistically in order for investors and users to embrace new technologies. The article argues that any future market acceptance for artificial photosynthesis will depend upon the prevalence of nine factors, which create conducive environments; the lack of the conditions engenders environments where they will likely be rejected. The conditions are (i) strong institutional capacity; (ii) political commitment; (iii) favourable legal and regulatory frameworks; (iv) competitive installation and/or production costs; (v) mechanisms for information and feedback; (vi) access to financing; (vii) prolific community and/or individual ownership and use; (viii) participatory project siting; and (ix) recognition of externalities or positive public image. PMID:26052424

  20. An Examination of Acceptable Navigation Accuracy for LISA Orbits

    National Research Council Canada - National Science Library

    Smythe, Reid W

    2007-01-01

    .... Preliminary analysis indicated the values of each parameter varied sinusoidally, and increasing the initial error conditions tended to reduce the time each parameter fell within the acceptable tolerance values...

  1. Stepping towards new parameterizations for non-canonical atmospheric surface-layer conditions

    Science.gov (United States)

    Calaf, M.; Margairaz, F.; Pardyjak, E.

    2017-12-01

    Representing land-atmosphere exchange processes as a lower boundary condition remains a challenge. This is partially a result of the fact that land-surface heterogeneity exists at all spatial scales and its variability does not "average" out with decreasing scales. Such variability need not rapidly blend away from the boundary thereby impacting the near-surface region of the atmosphere. Traditionally, momentum and energy fluxes linking the land surface to the flow in NWP models have been parameterized using atmospheric surface layer (ASL) similarity theory. There is ample evidence that such representation is acceptable for stationary and planar-homogeneous flows in the absence of subsidence. However, heterogeneity remains a ubiquitous feature eliciting appreciable deviations when using ASL similarity theory, especially in scalars such moisture and air temperature whose blending is less efficient when compared to momentum. The focus of this project is to quantify the effect of surface thermal heterogeneity with scales Ο(1/10) the height of the atmospheric boundary layer and characterized by uniform roughness. Such near-canonical cases describe inhomogeneous scalar transport in an otherwise planar homogeneous flow when thermal stratification is weak or absent. In this work we present a large-eddy simulation study that characterizes the effect of surface thermal heterogeneities on the atmospheric flow using the concept of dispersive fluxes. Results illustrate a regime in which the flow is mostly driven by the surface thermal heterogeneities, in which the contribution of the dispersive fluxes can account for up to 40% of the total sensible heat flux. Results also illustrate an alternative regime in which the effect of the surface thermal heterogeneities is quickly blended, and the dispersive fluxes provide instead a quantification of the flow spatial heterogeneities produced by coherent turbulent structures result of the surface shear stress. A threshold flow

  2. Resistance to radiation and concretes thermal cycles for conditioning of spent radioactive sources

    International Nuclear Information System (INIS)

    Gonzalez N, M.; Monroy G, F.; Gonzalez D, R. C.; Corona P, I. J.; Ortiz A, G.

    2014-10-01

    In order to know the concrete type most suitable for use as a matrix of conditioning of spent radioactive sources, concrete test tubes using 4 different types of cement were prepared: CPC 30-Rs Extra, CPC 30-R Impercem, CPC 30-R Rs and CPC 30-R with two gravel sizes >30 mm and <10 mm. The concrete test tubes were subjected to testing compressive strength after 28 days of hardening and after being irradiated and subjected to thermal cycles. Subsequently they were characterized by X-ray diffraction and scanning electron microscopy, in order to evaluate whether these concretes accredited the tests set by the NOM-019-Nucl-1995. The results show that the compressive strength of the hardened concretes to 28 days presents values between 36 and 25 MPa; applying irradiation the resistance may decrease to 30% of its original strength; and if subjected to high and low temperatures the ettringite formation also causes a decrease in resistance. The results show that concretes made from cement Impercem, Cruz Azul with gravel <10 mm comply with the provisions of standard and they can be used for conditioning of spent radioactive sources. (Author)

  3. Modeling and optimization of energy generation and storage systems for thermal conditioning of buildings targeting conceptual building design

    Energy Technology Data Exchange (ETDEWEB)

    Grahovac, Milica

    2012-11-29

    The thermal conditioning systems are responsible for almost half of the energy consump-tion by commercial buildings. In many European countries and in the USA, buildings account for around 40% of primary energy consumption and it is therefore vital to explore further ways to reduce the HVAC (Heating, Ventilation and Air Conditioning) system energy consumption. This thesis investigates the relationship between the energy genera-tion and storage systems for thermal conditioning of buildings (shorter: primary HVAC systems) and the conceptual building design. Certain building design decisions irreversibly influence a building's energy performance and, conversely, many generation and storage components impose restrictions on building design and, by their nature, cannot be introduced at a later design stage. The objective is, firstly, to develop a method to quantify this influence, in terms of primary HVAC system dimensions, its cost, emissions and energy consumption and, secondly, to enable the use of the developed method by architects during the conceptual design. In order to account for the non-stationary effects of the intermittent renewable energy sources (RES), thermal storage and for the component part load efficiencies, a time domain system simulation is required. An abstract system simulation method is proposed based on seven pre-configured primary HVAC system models, including components such as boil-ers, chillers and cooling towers, thermal storage, solar thermal collectors, and photovoltaic modules. A control strategy is developed for each of the models and their annual quasi-stationary simulation is performed. The performance profiles obtained are then used to calculate the energy consumption, carbon emissions and costs. The annuity method has been employed to calculate the cost. Optimization is used to automatically size the HVAC systems, based on their simulation performance. Its purpose is to identify the system component dimensions that provide

  4. Modeling and optimization of energy generation and storage systems for thermal conditioning of buildings targeting conceptual building design

    Energy Technology Data Exchange (ETDEWEB)

    Grahovac, Milica

    2012-11-29

    The thermal conditioning systems are responsible for almost half of the energy consump-tion by commercial buildings. In many European countries and in the USA, buildings account for around 40% of primary energy consumption and it is therefore vital to explore further ways to reduce the HVAC (Heating, Ventilation and Air Conditioning) system energy consumption. This thesis investigates the relationship between the energy genera-tion and storage systems for thermal conditioning of buildings (shorter: primary HVAC systems) and the conceptual building design. Certain building design decisions irreversibly influence a building's energy performance and, conversely, many generation and storage components impose restrictions on building design and, by their nature, cannot be introduced at a later design stage. The objective is, firstly, to develop a method to quantify this influence, in terms of primary HVAC system dimensions, its cost, emissions and energy consumption and, secondly, to enable the use of the developed method by architects during the conceptual design. In order to account for the non-stationary effects of the intermittent renewable energy sources (RES), thermal storage and for the component part load efficiencies, a time domain system simulation is required. An abstract system simulation method is proposed based on seven pre-configured primary HVAC system models, including components such as boil-ers, chillers and cooling towers, thermal storage, solar thermal collectors, and photovoltaic modules. A control strategy is developed for each of the models and their annual quasi-stationary simulation is performed. The performance profiles obtained are then used to calculate the energy consumption, carbon emissions and costs. The annuity method has been employed to calculate the cost. Optimization is used to automatically size the HVAC systems, based on their simulation performance. Its purpose is to identify the system component dimensions that provide minimal

  5. Thermal and Electrical Characterization of a Semi-Transparent Dye-Sensitized Photovoltaic Module under Real Operating Conditions

    Directory of Open Access Journals (Sweden)

    Cristina Cornaro

    2018-01-01

    Full Text Available Dye-sensitized solar cell technology is having an important role in renewable energy research due to its features and low-cost manufacturing processes. Devices based on this technology appear very well suited for integration into glazing systems due to their characteristics of transparency, color tuning and manufacturing directly on glass substrates. Field data of thermal and electrical characteristics of dye-sensitized solar modules (DSM are important since they can be used as input of building simulation models for the evaluation of their energy saving potential when integrated into buildings. However, still few studies in the literature provide this information. The study presented here aims to contribute to fill this lack providing a thermal and electrical characterization of a DSM in real operating conditions using a method developed in house. This method uses experimental data coming from test boxes exposed outdoor and dynamic simulation to provide thermal transmittance (U-value and solar heat gain coefficient (SHGC of a DSM prototype. The device exhibits a U-value of 3.6 W/m2·K, confirmed by an additional measurement carried on in the lab using a heat flux meter, and a SHGC of 0.2, value compliant with literature results. Electrical characterization shows an increase of module power with respect to temperature resulting DSM being suitable for integration in building facades.

  6. Exergy and energy analyses of two different types of PCM based thermal management systems for space air conditioning applications

    International Nuclear Information System (INIS)

    Tyagi, V.V.; Pandey, A.K.; Buddhi, D.; Tyagi, S.K.

    2013-01-01

    Highlights: ► Calcium chloride hexahydrate (CaCl 2 ⋅6H 2 O) as a PCM was used in this study. ► Two different capsulated system (HDPE based panel and balls) were designed. ► The results of CaCl 2 ⋅6H 2 O are very attractive for space air conditioning. ► Energy and exergy analyses for space cooling applications. - Abstract: This communication presents the experimental study of PCM based thermal management systems for space heating and cooling applications using energy and exergy analysis. Two different types of based thermal management system (TMS-I and TMS-II) using calcium chloride hexahydrate as the heat carrier has been designed, fabricated and studied for space heating and cooling applications at a typical climatic zone in India. In the first experimental arrangement the charging of PCM has been carried out with air conditioning system while discharging has been carried out using electric heater for both the thermal management systems. While in the second arrangement the charging of PCM has been carried out by solar energy and the discharging has been carried out by circulating the cooler ambient air during the night time. In the first experiment, TMS-I is found to be more effective than that of TMS-II while it was found to be reverse in the case of second experiment for both the charging and discharging processes not only for energetic but also for the exergetic performances

  7. Account of External Cooling Medium Temperature while Modeling Thermal Processes in Power Oil-Immersed Transformers

    OpenAIRE

    Yu. A. Rounov; O. G. Shirokov; D. I. Zalizny; D. M. Los

    2004-01-01

    The paper proposes a thermal model of a power oil-immersed transformer as a system of four homogeneous bodies: winding, oil, core and cooling medium. On the basis of experimental data it is shown that such model describes more precisely actual thermal processes taking place in a transformer than the thermal model accepted in GOST 14209-85.

  8. Thermal design of a modern, air-conditioned, single-floor, solar-powered desert house

    KAUST Repository

    Serag-Eldin, M. A.

    2011-12-01

    The paper presents a thermal analysis of a single-floor, solar-powered desert house. The house is air-conditioned and provides all modern comforts and facilities. Electrical power, which drives the entire energy system, is generated by roof-mounted photovoltaic modules. The modules are fixed on special cradles which fold at night to expose the roof to the night sky, thereby enhancing night-time cooling, which is substantial in the desert environment. A detailed dynamic heat transfer analysis is conducted for the building envelope, coupled with a solar radiation model. Application to a typical Middle-Eastern desert site reveals that indeed such a design is feasible with present-day technology; and should be even more attractive with future advances in technology. © 2011 Copyright Taylor and Francis Group, LLC.

  9. Anisotropic Thermal Diffusivities of Plasma-Sprayed Thermal Barrier Coatings

    Science.gov (United States)

    Akoshima, Megumi; Takahashi, Satoru

    2017-09-01

    Thermal barrier coatings (TBCs) are used to shield the blades of gas turbines from heat and wear. There is a pressing need to evaluate the thermal conductivity of TBCs in the thermal design of advanced gas turbines with high energy efficiency. These TBCs consist of a ceramic-based top coat and a bond coat on a superalloy substrate. Usually, the focus is on the thermal conductivity in the thickness direction of the TBC because heat tends to diffuse from the surface of the top coat to the substrate. However, the in-plane thermal conductivity is also important in the thermal design of gas turbines because the temperature distribution within the turbine cannot be ignored. Accordingly, a method is developed in this study for measuring the in-plane thermal diffusivity of the top coat. Yttria-stabilized zirconia top coats are prepared by thermal spraying under different conditions. The in-plane and cross-plane thermal diffusivities of the top coats are measured by the flash method to investigate the anisotropy of thermal conduction in a TBC. It is found that the in-plane thermal diffusivity is higher than the cross-plane one for each top coat and that the top coats have significantly anisotropic thermal diffusivity. The cross-sectional and in-plane microstructures of the top coats are observed, from which their porosities are evaluated. The thermal diffusivity and its anisotropy are discussed in detail in relation to microstructure and porosity.

  10. Optimization of the thermal conditions for processing hatchery waste eggs as meal for feed.

    Science.gov (United States)

    Chiu, W Z; Wei, H W

    2011-05-01

    The purpose of this study was to optimize the thermal conditions for processing hatchery waste eggs (HWE) into rich feedstuff with lower electricity consumption by using response surface methodology. In the study, the effects of processing temperature and time on HWE meal (HWEM) quality and production were evaluated. As the results indicate, optimization was obtained when the processing lasted for 23 h at the fixed temperature of 65°C, resulting in higher protein digestibility in vitro (89.6%) and DM (88.5%) content of HWEM with lower electricity consumption (82.4 kWh/60 kg of HWE). No significant differences existed between the quality values predicted by mathematical formulae and those obtained through practical analyses in DM (87 vs. 88.5%), CP (39.2 vs. 38.3%), protein digestibility in vitro (90.7 vs. 89.6%), and electricity consumed (80.8 vs. 82.4 kWh/60 kg of HWE). Furthermore, the product derived from the optimized processing conditions had better biosecurity; Salmonella spp. were not found and Escherichia coli levels were substantially reduced (from 10(7) to 10(4) cfu/g). In summary, HWEM of superior quality can be produced when the processing conditions optimized in the current research are utilized.

  11. The NTF Inlet Guide Vanes Thermal Gradient Problem and Its Mitigation

    Science.gov (United States)

    Venkat, Venki S.; Paryz, Roman W.; Bissett, Owen W.; Kilgore, W.

    2013-01-01

    The National Transonic Facility (NTF) utilizes Inlet Guide Vanes (IGV) to provide precise, quick response Mach number control for the tunnel. During cryogenic operations, the massive IGV structure can experience large thermal gradients, measured as "Delta T or (Delta)T", between the IGV ring and its support structure called the transfer case. If these temperature gradients are too large, the IGV structure can be stressed beyond its safety limit and cease operation. In recent years, (Delta)T readings exceeding the prescribed safety limits were observed frequently during cryogenic operations, particularly during model access. The tactical operation methods of the tunnel to minimize (Delta)T did not always succeed. One obvious option to remedy this condition is to warm up the IGV structure by disabling the main drive operation, but this "natural" warm up method can takes days in some cases, resulting in productivity loss. This paper documents the thermal gradient problem associated with the IGV structure during cryogenic operation and how the facility has recently achieved an acceptable mitigation which has resulted in improved efficiency of operations.

  12. Acceptance sampling using judgmental and randomly selected samples

    Energy Technology Data Exchange (ETDEWEB)

    Sego, Landon H.; Shulman, Stanley A.; Anderson, Kevin K.; Wilson, John E.; Pulsipher, Brent A.; Sieber, W. Karl

    2010-09-01

    We present a Bayesian model for acceptance sampling where the population consists of two groups, each with different levels of risk of containing unacceptable items. Expert opinion, or judgment, may be required to distinguish between the high and low-risk groups. Hence, high-risk items are likely to be identifed (and sampled) using expert judgment, while the remaining low-risk items are sampled randomly. We focus on the situation where all observed samples must be acceptable. Consequently, the objective of the statistical inference is to quantify the probability that a large percentage of the unsampled items in the population are also acceptable. We demonstrate that traditional (frequentist) acceptance sampling and simpler Bayesian formulations of the problem are essentially special cases of the proposed model. We explore the properties of the model in detail, and discuss the conditions necessary to ensure that required samples sizes are non-decreasing function of the population size. The method is applicable to a variety of acceptance sampling problems, and, in particular, to environmental sampling where the objective is to demonstrate the safety of reoccupying a remediated facility that has been contaminated with a lethal agent.

  13. The effect of adiabatic and conducting wall boundary conditions on LES of a thermal mixing tee

    International Nuclear Information System (INIS)

    Howard, Richard J.A.; Pasutto, Thomas

    2009-01-01

    In this paper preliminary LES simulations are carried out of the FATHERINO mixing T junction experiment. In this experiment 80degC hot water enters a lateral steel pipe which has a diameter of D=0.054m, at a speed of 1.04m/s and meets 5degC cold water which enters a perpendicular steel pipe branch that also has a diameter D=0.054m but this time at a lower speed of 0.26m/s. The modelling of the steel pipe walls is tested by comparing adiabatic and 1D conducting wall boundary conditions. The numerical grid used contains approximately 440,000 hexahedral elements. The near wall refinement is not sufficient to resolve the near wall boundary layer (y + approx. = 32) and a standard logarithmic boundary condition is used. A method known as the synthetic eddy method is used to generate the turbulent flow at the pipe inlets. Three different LES models are used (Smagorinsky, dynamic Smagorinsky and wale) to resolve the subgrid turbulent motion beyond the wall grid. An additional test is carried out where no subgrid model is used with only the wall modelling being applied. The results show that the wale model generates much less resolved turbulence than the other cases and this model shows virtually no difference between the two methods of wall thermal modelling. The dynamic Smagorinsky model shows that, downstream of the mixing T, the lower wall remains at a lower temperature for longer when the adiabatic boundary condition is applied. The Smagorinsky model is found to produce the highest level of resolved temperature fluctuation. For this model the 1D thermal modelling approach increases the unsteadiness of both the velocity and temperature fields at the onset of the mixing and in the middle of the pipe downstream of the T junction. However near the lower wall the 1D thermal modelling approach tends to reduce the unsteadiness. The case with no subgrid modelling shows higher levels of turbulence kinetic energy but lower levels of temperature fluctuation than the cases with

  14. Thermal performance and efficiency of supercritical nuclear reactors

    International Nuclear Information System (INIS)

    Romney Duffey; Tracy Zhou; Hussam Khartabil

    2009-01-01

    The paper reviews the major advances and innovative aspects of the thermal performance of recent concepts for super-critical water-cooled nuclear reactors (SCWR). The concepts are based on the extensive experience in the thermal power industry with super and ultra-supercritical boilers and turbines. The challenges and goals of increased efficiency, reduced cost, enhanced safety and co-generation have been pursued over the last ten years, and have resulted both in viable concepts and a vibrant defined R and D effort. The supercritical concept has wide acceptance among industry, as it reflects standard engineering practices and current thermal plant technology that is being already deployed. The SCWR concept represents a continuous development of water-cooled reactor technology, which utilizes the best and latest advances made in the thermal power industry. (author)

  15. Analysis of Technical State of Thermal and Mechanical Equipment of Thermal Power Stations in the Republic of Belarus under Conditions of Investment Deficit

    Directory of Open Access Journals (Sweden)

    S. N. Shichko

    2004-01-01

    Full Text Available The paper contains an analysis of the equipment state at a number of thermal power stations. This analysis is made on the basis of indifferent curves. Relationship of two factors is taken as a criterion for estimation of the equipment state. These factors are faultiness (parameter of failure fi"equency and operating time from the moment when the equipment was put into operation. It is noted that operation of the equipment in excess of specified life without replacement of so-called «weab> elements and estimation of metal state will lead to conditions of high risk in opieration of such equipment.

  16. Thermal conductivity at different humidity conditions

    DEFF Research Database (Denmark)

    Kristiansen, Finn Harken; Rode, Carsten

    1999-01-01

    by an accumulation of moisture as condensation in the parts of the insulation that lie immediately close to the cold side of the apparatus. The high l-values found are therefore of no practical importance in structures where no condensation occurs. Disregarding these condensation situations, the maximum increase...... humidified air can pass. Thus, it is possible to build up different degrees of moisture on each side of the test specimen.The thermal conductivity is determined for the following types of alternative insulation: sheep's wool, flax, paper insulation, perlite and mineral wool. The insulation products were...... Ekofiber Vind, Herawool (without support fibres), Heraflax, Isodan with and without salts, Miljø Isolering with and without salts, Perlite (water-repellent), and Rockwool A-batts for comparison.All measurements of the materials started with no affection of moisture. Nevertheless, results were achieved...

  17. Responsible technology acceptance

    DEFF Research Database (Denmark)

    Toft, Madeleine Broman; Schuitema, Geertje; Thøgersen, John

    2014-01-01

    As a response to climate change and the desire to gain independence from imported fossil fuels, there is a pressure to increase the proportion of electricity from renewable sources which is one of the reasons why electricity grids are currently being turned into Smart Grids. In this paper, we focus...... on private consumers’ acceptance of having Smart Grid technology installed in their home. We analyse acceptance in a combined framework of the Technology Acceptance Model and the Norm Activation Model. We propose that individuals are only likely to accept Smart Grid technology if they assess usefulness...... in terms of a positive impact for society and the environment. Therefore, we expect that Smart Grid technology acceptance can be better explained when the well-known technology acceptance parameters included in the Technology Acceptance Model are supplemented by moral norms as suggested by the Norm...

  18. Effect of thermal exposure on the residual stress relaxation in a hardened cylindrical sample under creep conditions

    Science.gov (United States)

    Radchenko, V. P.; Saushkin, M. N.; Tsvetkov, V. V.

    2016-05-01

    This paper describes the effect of thermal exposure (high-temperature exposure) ( T = 675°C) on the residual creep stress relaxation in a surface hardened solid cylindrical sample made of ZhS6UVI alloy. The analysis is carried out with the use of experimental data for residual stresses after micro-shot peening and exposures to temperatures equal to T = 675°C during 50, 150, and 300 h. The paper presents the technique for solving the boundary-value creep problem for the hardened cylindrical sample with the initial stress-strain state under the condition of thermal exposure. The uniaxial experimental creep curves obtained under constant stresses of 500, 530, 570, and 600 MPa are used to construct the models describing the primary and secondary stages of creep. The calculated and experimental data for the longitudinal (axial) tensor components of residual stresses are compared, and their satisfactory agreement is determined.

  19. Effects of ageing and moisture content on thermal properties of ...

    African Journals Online (AJOL)

    Effects of ageing and moisture content on thermal properties of cassava roots ... after harvest coupled with non-‐availability of acceptable storage alternatives. ... the properties simultaneously based on the transient line heat source method.

  20. Experimental determination about thermal comfort conditions in buildings; Determinacion experimental de las condiciones de confort termico en edificaciones

    Energy Technology Data Exchange (ETDEWEB)

    Ambriz Garcia, Juan Jose; Garcia Chavez, Jose Roberto; Paredes Rubio, Hernando Romero [Universidad Autonoma Metropolitana (Mexico)]. E-mail: agj@xanum.uam.mx; jgc@correo.azc.uam.mx; hrp@xanum.uam.mx

    2006-04-15

    This paper analyzes the thermal comfort importance in a building. And the influence it exerts on quality of life as well as the efficiency of people work activities. There are comments about some models which better help to estimate the recommended temperature levels. The experimental evaluation results from a Mexico City population sampler are presented. This work was done in a Controlled Environment Laboratory; the obtained outcomes proved the preferences occupants exceed the comfort zone greatest limit accepted in the reference international standards. The meaning of this conclusion is thermal comfort can be reached with higher temperatures and consequently an energy consumption and an environment impact decrease. [Spanish] En este trabajo se analiza la importancia que tiene el confort termico en la calidad de vida de las personas que ocupan una edificacion y en la eficiencia de sus actividades. Se comentan algunos modelos con los cuales se estiman los niveles de temperatura recomendados y se presentan los resultados de una evaluacion experimental realizada en un Laboratorio de Ambiente Controlado con una muestra de la poblacion del Distrito Federal. Los resultados que se obtuvieron demuestran que los ocupantes tienen preferencias que rebasan el limite superior de la zona de confort comunmente aceptada en los estandares internacionales de referencia. Esto quiere decir que el confort puede lograrse con mayores temperaturas, lo que se traduce en menor consumo de energia y menor impacto en el ambiente.

  1. Differences between young adults and elderly in thermal comfort, productivity and thermal physiology in response to a moderate temperature drift

    DEFF Research Database (Denmark)

    Schellen, Lisje; Lichtenbelt, Wouter van Marken; Loomans, Marcel

    2010-01-01

    thermal condition differ between young adults and elderly. There is a lack of studies that describe the effect of aging on thermal comfort and productivity during a moderate temperature drift. In this study, the effect of a moderate temperature drift on physiological responses, thermal comfort......Results from naturally ventilated buildings show that allowing the indoor temperature to drift does not necessarily result in thermal discomfort and may allow for a reduction in energy use. However, for stationary conditions, several studies indicate that the thermal neutral temperature and optimum......, temperature drift: first 4 h: +2 K/h, last 4 h: –2 K/h. The results indicate that thermal sensation of the elderly was, in general, 0.5 scale units lower in comparison with their younger counterparts. Furthermore, the elderly showed more distal vasoconstriction during both conditions. Nevertheless, TS...

  2. The influence of outdoor thermal environment on young Japanese females

    Science.gov (United States)

    Kurazumi, Yoshihito; Ishii, Jin; Kondo, Emi; Fukagawa, Kenta; Bolashikov, Zhecho Dimitrov; Sakoi, Tomonori; Tsuchikawa, Tadahiro; Matsubara, Naoki; Horikoshi, Tetsumi

    2014-07-01

    acceptability raised the mean skin temperature even for thermal environment conditions in which ETFe was high.

  3. Development of thermal conditioning technology for alpha-contaminated wastes

    International Nuclear Information System (INIS)

    Kim, Joon Hyung; Kim, H. Y.; Kim, J. G.

    2001-04-01

    To develop a thermal conditioning technology for alpha-contaminated wastes, which are presumed to generate from pyrochemical processing of spent fuel, research on the three different fields have been performed; incineration, off-gas treatment, and vitrification/cementation technology. Through the assessment on the amount of alpha-contaminated waste and incineration characterises, an oxygen-enriched incineration process, which can greatly reduce the off-gas volume, was developed by our own technology. Trial burn test with paper waste resulted in a reduction of off-gas volume by 3.5. A study on the behavior and adsorption of nuclides/heavy metals at high-temperature was performed to develop an efficient removal technology. Off-gas treatment technologies for radioiodine at high-temperature and 14 CO 2 , acidic gases, and radioactive gaseous wastes such as Xe/Kr at room temperature were established. As a part of development of high-level waste solidification technology, manufacture of high-frequency induction melter, fabrication and characterization of base-glass media fabricated with spent HEPA filter medium, and development of titanate ceramic material as a precursor of SYNROC by a self-combustion method were performed. To develop alpha-contaminated waste solidification technology, a process to convert periodontal in the cement matrix to calcite with SuperCritical Carbon Dioxide (SCCD) was manufactured. The SCCD treatment enhanced the physicochemical properties of cement matrices, which increase the long-term integrity of cement waste forms during transportation and storage

  4. Nevada National Security Site Waste Acceptance Criteria

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-06-01

    This document establishes the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO), Nevada National Security Site Waste Acceptance Criteria (NNSSWAC). The NNSSWAC provides the requirements, terms, and conditions under which the Nevada National Security Site (NNSS) will accept the following: • DOE hazardous and non-hazardous non-radioactive classified waste • DOE low-level radioactive waste (LLW) • DOE mixed low-level waste (MLLW) • U.S. Department of Defense (DOD) classified waste The LLW and MLLW listed above may also be classified waste. Classified waste is the only waste accepted for disposal that may be non-radioactive and shall be required to meet the waste acceptance criteria for radioactive waste as specified in this document. Classified waste may be sent to the NNSS as classified matter. Section 3.1.18 provides the requirements that must be met for permanent burial of classified matter. The NNSA/NFO and support contractors are available to assist the generator in understanding or interpreting this document. For assistance, please call the NNSA/NFO Environmental Management Operations (EMO) at (702) 295-7063, and the call will be directed to the appropriate contact.

  5. Nevada National Security Site Waste Acceptance Criteria

    International Nuclear Information System (INIS)

    2013-01-01

    This document establishes the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO), Nevada National Security Site Waste Acceptance Criteria (NNSSWAC). The NNSSWAC provides the requirements, terms, and conditions under which the Nevada National Security Site (NNSS) will accept the following: DOE hazardous and non-hazardous non-radioactive classified waste; DOE low-level radioactive waste (LLW); DOE mixed low-level waste (MLLW); and, U.S. Department of Defense (DOD) classified waste. The LLW and MLLW listed above may also be classified waste. Classified waste is the only waste accepted for disposal that may be non-radioactive and shall be required to meet the waste acceptance criteria for radioactive waste as specified in this document. Classified waste may be sent to the NNSS as classified matter. Section 3.1.18 provides the requirements that must be met for permanent burial of classified matter. The NNSA/NFO and support contractors are available to assist the generator in understanding or interpreting this document. For assistance, please call the NNSA/NFO Environmental Management Operations (EMO) at (702) 295-7063, and the call will be directed to the appropriate contact.

  6. Evidentiary requirements to identify potentially acceptable sites (PAS) in crystalline rock

    International Nuclear Information System (INIS)

    Comella, P.A.; Smith, B.H.

    1985-01-01

    This report contains information on the evidentiary requirements to identify potentially acceptable sites in crystalline rock for waste disposal. Topics addressed include: chronology, key regulatory assumptions, statutory framework for identifying potentially acceptable sites, application of 10 disqualifiers, consideration of favorable and potentially adverse conditions, a composite favorability analysis, and a proposed outline for PAS identification decision document

  7. Acceptance of Others, Feeling of Being Accepted and Striving for Being Accepted Among the Representatives of Different Kinds of Occupations

    Directory of Open Access Journals (Sweden)

    Gergana Stanoeva

    2012-05-01

    Full Text Available This paper deals with an important issue related to the human attitudes and needs in interpersonal and professional aspects. The theoretical part deals with several psychological components of the self-esteem and esteem of the others – acceptance of the others, feeling of being accepted, need for approval. Some gender differences in manifestations of acceptance and feeling of being accepted at the workplace are discussed. This article presents some empirical data for the degree of acceptance of others, feeling of being accepted and the strive for being accepted among the representatives of helping, pedagogical, administrative and economic occupations, as well as non-qualified workers. The goals of the study were to reveal the interdependency between these constructs and to be found some significant differences between the representatives of the four groups of occupations. The methods of the first study were W. Fey’s scales “Acceptance of others”, and “How do I feel accepted by others”. The method of the second study was Crown and Marlowe Scale for Social Desirability. The results indicated some significant differences in acceptance of others and feeling of being accepted between the non-qualified workers and the representatives of helping, administrative and economic occupations. There were not any significant difference in strive for being accepted between the fouroccupational groups.

  8. Numerical Investigation of the Thermal Regime of Underground Channel Heat Pipelines Under Flooding Conditions with the Use of a Conductive-Convective Heat Transfer Model

    Science.gov (United States)

    Polovnikov, V. Yu.

    2018-05-01

    This paper presents the results of numerical analysis of thermal regimes and heat losses of underground channel heating systems under flooding conditions with the use of a convective-conductive heat transfer model with the example of the configuration of the heat pipeline widely used in the Russian Federation — a nonpassage ferroconcrete channel (crawlway) and pipelines insulated with mineral wool and a protective covering layer. It has been shown that convective motion of water in the channel cavity of the heat pipeline under flooding conditions has no marked effect on the intensification of heat losses. It has been established that for the case under consideration, heat losses of the heat pipeline under flooding conditions increase from 0.75 to 52.39% due to the sharp increase in the effective thermal characteristics of the covering layer and the heat insulator caused by their moistening.

  9. Operating modes of high-Tc composite superconductors and thermal runaway conditions under current charging

    International Nuclear Information System (INIS)

    Romanovskii, V R; Watanabe, K

    2006-01-01

    The operating thermal and electric modes of a high-T c superconducting composite in partially and fully penetrated states induced by the charging current are investigated. They were studied under conditions in which the current charging rate, the volume fraction of the superconductor in a composite or the temperature of the cooling bath were changed. The transient behaviour of the voltage-current dependence, which is characteristic during stable and unstable increases in electric field inside the composite under a continuous current charging, is discussed. Simulations were done using zero- and one-dimensional steady and unsteady thermoelectric models with a power equation describing the virgin voltage-current characteristic of a superconductor. It is found that some thermoelectric trends underlie the shape of the voltage-current characteristic of the high-T c superconducting composite. These have to be considered during experiments in which the critical or quench currents are defined. First, in the initial stage of the fully penetrated regime (in the low voltage range), the electric field distribution does not have a uniform character. These states depend on the volume fraction of the superconductor and the current charging rate: the higher these quantities, the higher the heterogeneity of the electric field. Second, during the stable over-critical regime (in the high voltage range) occurring in complete penetration modes, the evolution of the electric field may depend on the relevant temperature increase of a composite according to the corresponding increase in its temperature-dependent heat capacity. Consequently, the shape of the voltage-current characteristic of a composite high-T c superconductor during continuous current charging, both before and after thermal runaway, has only a positive slope. Moreover, it is proved that the growth of the fully penetrated part of the voltage-current characteristic becomes less intensive when the current charging rate or the

  10. Estec2003: European solar thermal energy conference. Proceedings; Estec2003: Europaeische Solarthermie-Konferenz. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    In December 2002 more than 40 solar thermal companies and associations joined forces in the European Solar Thermal Industry Federation (ESTIF), to strengthen support for this clean technology on the European level. ESTIF aims at building a close partnership between industry and public authorities in order to overcome the main barriers to growth. Over the last 6 months we have seen some positive developments, which we could build upon. Here are some examples: 1. Germany, the country with the largest demand for solar thermal technology, is back on track to repeat the growth rates we have witnessed in the 1990s. 2. The rules for the solar Keymark quality label were approved by CEN board in January 2003. 3. The city of Madrid became the first European capital to follow the example of Barcelona in requiring the use of solar thermal in new residential buildings. 4. The long awaited ''Sun in Action II - a solar thermal strategy for Europe was published last month. 5. Now, the first European Solar Thermal Energy Conference brings together decision makers from industry and politics to discuss the future of renewable heating and cooling in Europe. - Solar thermal has a great potential - 1.4 billion square meters in the 15 EU member states alone. 99% of this potential are still to be developed. ESTIF has made it its mission 'to achieve high priority and acceptance for solar thermal as a key element for sustainable heating and cooling in Europe and to work for the implementation, as soon as possible, of all steps necessary to realise the high potential of solar thermal'. With estec2003 we offer a platform to exchange information and opinions concerning how this goal can be achieved. The developments in different countries show that the use of solar thermal technologies does not depend on climatic conditions alone. (orig.)

  11. Pressurized Thermal Shock, Pts

    International Nuclear Information System (INIS)

    Boyd, C.

    2008-01-01

    Pressurized Thermal Shock (Pts) refers to a condition that challenges the integrity of the reactor pressure vessel. The root cause of this problem is the radiation embrittlement of the reactor vessel. This embrittlement leads to an increase in the reference temperature for nil ductility transition (RTNDT). RTNDT can increase to the point where the reactor vessel material can loose fracture toughness during overcooling events. The analysis of the risk of having a Pts for a specific plant is a multi-disciplinary problem involving probabilistic risk analysis (PRA), thermal-hydraulic analysis, and ultimately a structural and fracture analysis of the vessel wall. The PRA effort involves the postulation of overcooling events and ultimately leads to an integrated risk analysis. The thermal-hydraulic effort involves the difficult task of predicting the system behavior during a postulated overcooling scenario with a special emphasis on predicting the thermal and mechanic loadings on the reactor pressure vessel wall. The structural and fracture analysis of the reactor vessel wall relies on the thermal-hydraulic conditions as boundary conditions. The US experience has indicated that medium and large diameter primary system breaks dominate the risk of Pts along with scenarios that involve a stuck open valve (and associated system cooldown) that recloses resulting in system re-pressurization while the vessel wall is cool.

  12. Acceptability, acceptance and decision making

    International Nuclear Information System (INIS)

    Ackerschott, H.

    2002-01-01

    There is a fundamental difference between the acceptability of a civilizatory or societal risk and the acceptability of the decision-making process that leads to a civilizatory or societal risk. The analysis of individual risk decisions - regarding who, executes when which indisputably hazardous, unhealthy or dangerous behaviour under which circumstances - is not helpful in finding solutions for the political decisions at hand in Germany concerning nuclear energy in particular or energy in general. The debt for implementation of any technology, in the sense of making the technology a success in terms of broad acceptance and general utilisation, lies with the particular industry involved. Regardless of the technology, innovation research identifies the implementation phase as most critical to the success of any innovation. In this sense, nuclear technology is at best still an innovation, because the implementation has not yet been completed. Fear and opposition to innovation are ubiquitous. Even the economy - which is often described as 'rational' - is full of this resistance. Innovation has an impact on the pivotal point between stability, the presupposition for the successful execution of decisions already taken and instability, which includes insecurity, but is also necessary for the success of further development. By definition, innovations are beyond our sphere of experience; not at the level of reliability and trust yet to come. Yet they are evaluated via the simplifying heuristics for making decisions proven not only to be necessary and useful, but also accurate in the familiar. The 'settlement of the debt of implementation', the accompanying communication, the decision-making procedures concerning the regulation of averse effects of the technology, but also the tailoring of the new technology or service itself must be directed to appropriate target groups. But the group often aimed at in the nuclear debate, the group, which largely determines political

  13. Account of External Cooling Medium Temperature while Modeling Thermal Processes in Power Oil-Immersed Transformers

    Directory of Open Access Journals (Sweden)

    Yu. A. Rounov

    2004-01-01

    Full Text Available The paper proposes a thermal model of a power oil-immersed transformer as a system of four homogeneous bodies: winding, oil, core and cooling medium. On the basis of experimental data it is shown that such model describes more precisely actual thermal processes taking place in a transformer than the thermal model accepted in GOST 14209-85.

  14. Evaluation of conditions of SNCR in small boilers

    International Nuclear Information System (INIS)

    Kullendorff, A.; Lorentzon, K.

    1996-04-01

    The report describes the first part of a project 'SNCR for small boilers', supported by Vaermeforsk (Thermal Engineering Research Institute), with the purpose of assessing the potential for SNCR in small boilers. Given favourable conditions, the project was to be continued in a second part with the demonstration of a SNCR system in a small boiler (or several boilers). During the base establishment, the temperatures in four locations per boiler, in a couple of horizontal or vertical levels and at 2-3 thermal outputs, were measured. Out of the four locations two showed temperatures mainly within the theoretical temperature window for SNCR. These locations were used during the try-out tests to inject urea and ammonia. The locations and the equipment used during the try-out tests together with existing operation strategies seem to limit the reduction levels to approximately 10-20% at acceptable levels of ammonia slip. The measurements and try-out tests carried out does not provide enough basis for forming any general conclusions concerning SNCR in small boilers. Neither the base establishment nor the try-out tests included any optimisation of the boilers regarding the operation strategy or, for the try-out tests, locations and equipment (drop size, flow shape and direction). Therefore, it is likely to believe that better results can be obtained, given other conditions of operation and using well established SNCR technology, adapted to the circumstances. 2 refs, 27 figs, 5 tabs

  15. Constraining the thermal conditions of impact environments through integrated low-temperature thermochronometry and numerical modeling

    Science.gov (United States)

    Kelly, N. M.; Marchi, S.; Mojzsis, S. J.; Flowers, R. M.; Metcalf, J. R.; Bottke, W. F., Jr.

    2017-12-01

    Impacts have a significant physical and chemical influence on the surface conditions of a planet. The cratering record is used to understand a wide array of impact processes, such as the evolution of the impact flux through time. However, the relationship between impactor size and a resulting impact crater remains controversial (e.g., Bottke et al., 2016). Likewise, small variations in the impact velocity are known to significantly affect the thermal-mechanical disturbances in the aftermath of a collision. Development of more robust numerical models for impact cratering has implications for how we evaluate the disruptive capabilities of impact events, including the extent and duration of thermal anomalies, the volume of ejected material, and the resulting landscape of impacted environments. To address uncertainties in crater scaling relationships, we present an approach and methodology that integrates numerical modeling of the thermal evolution of terrestrial impact craters with low-temperature, (U-Th)/He thermochronometry. The approach uses time-temperature (t-T) paths of crust within an impact crater, generated from numerical simulations of an impact. These t-T paths are then used in forward models to predict the resetting behavior of (U-Th)/He ages in the mineral chronometers apatite and zircon. Differences between the predicted and measured (U-Th)/He ages from a modeled terrestrial impact crater can then be used to evaluate parameters in the original numerical simulations, and refine the crater scaling relationships. We expect our methodology to additionally inform our interpretation of impact products, such as lunar impact breccias and meteorites, providing robust constraints on their thermal histories. In addition, the method is ideal for sample return mission planning - robust "prediction" of ages we expect from a given impact environment enhances our ability to target sampling sites on the Moon, Mars or other solar system bodies where impacts have strongly

  16. Durability and Design Issues of Thermal/environmental Barrier Coatings on Sic/sic Ceramic Matrix Composites Under 1650 C Test Conditions

    Science.gov (United States)

    Zhu, Dong-Ming; Choi, Sung R.; Ghosn, Louis J.; Miller, Robert A.

    2004-01-01

    Ceramic thermal/environmental barrier coatings for SiC-based ceramics will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. However, the coating durability remains a major concern with the ever-increasing temperature requirements. Currently, advanced T/EBC systems, which typically include a high temperature capable zirconia- (or hahia-) based oxide top coat (thermal barrier) on a less temperature capable mullite/barium-strontium-aluminosilicate (BSAS)/Si inner coat (environmental barrier), are being developed and tested for higher temperature capability Sic combustor applications. In this paper, durability of several thermal/environmental barrier coating systems on SiC/SiC ceramic matrix composites was investigated under laser simulated engine thermal gradient cyclic, and 1650 C (3000 F) test conditions. The coating cracking and delamination processes were monitored and evaluated. The effects of temperature gradients and coating configurations on the ceramic coating crack initiation and propagation were analyzed using finite element analysis (FEA) models based on the observed failure mechanisms, in conjunction with mechanical testing results. The environmental effects on the coating durability will be discussed. The coating design approach will also be presented.

  17. Subjective study of thermal acceptability of novel enhanced displacement ventilation system and implication of occupants' personal control

    DEFF Research Database (Denmark)

    Sun, Weimeng; Cheong, K.W.D.; Melikov, Arsen Krikor

    2012-01-01

    with DV and constant heat load at different supply air temperatures, namely 20, 22, and 24 °C and room air temperatures, 22, 24, and 26 °C. Subjective assessments were carried out with 32 tropically-acclimatized college students who were given the choice to adjust the fan speed. Subjects' thermal comfort...... of 22 and 24 °C when the fans were in operation. It was also found that the Whole Body Thermal Sensation (WBTS) reported by the subjects was correlated with the Local Thermal Sensation (LTS) at the waist, the arms, the calf and the feet when the novel DV system was employed. An expression which allows...

  18. Thermal Properties of Carbon Nanotube–Copper Composites for Thermal Management Applications

    Directory of Open Access Journals (Sweden)

    Jia Chengchang

    2010-01-01

    Full Text Available Abstract Carbon nanotube–copper (CNT/Cu composites have been successfully synthesized by means of a novel particles-compositing process followed by spark plasma sintering (SPS technique. The thermal conductivity of the composites was measured by a laser flash technique and theoretical analyzed using an effective medium approach. The experimental results showed that the thermal conductivity unusually decreased after the incorporation of CNTs. Theoretical analyses revealed that the interfacial thermal resistance between the CNTs and the Cu matrix plays a crucial role in determining the thermal conductivity of bulk composites, and only small interfacial thermal resistance can induce a significant degradation in thermal conductivity for CNT/Cu composites. The influence of sintering condition on the thermal conductivity depended on the combined effects of multiple factors, i.e. porosity, CNTs distribution and CNT kinks or twists. The composites sintered at 600°C for 5 min under 50 MPa showed the maximum thermal conductivity. CNT/Cu composites are considered to be a promising material for thermal management applications.

  19. New acrylic resin composite with improved thermal diffusivity.

    Science.gov (United States)

    Messersmith, P B; Obrez, A; Lindberg, S

    1998-03-01

    Studies have shown that physical characteristics of denture base materials may affect patient acceptance of denture prostheses by altering sensory experience of food during mastication. Thermal diffusivity is one material property that has been cited as being important in determining gustatory response, with denture base acrylic resins having low thermal diffusivity compared with denture base metal alloys. This study prepared and characterized experimental acrylic resin composite material with increased thermal diffusivity. Sapphire (Al2O3) whiskers were added to conventional denture base acrylic resin during processing to achieve loadings of 9.35% and 15% by volume. Cylindrical test specimens containing an embedded thermocouple were used to determine thermal diffusivity over a physiologic temperature range (0 degree to 70 degrees C). Thermal diffusivities of the sapphire containing composites were found to be significantly higher than the unmodified acrylic resin. Thermal diffusivity was found to increase in proportion to the volume percentage of sapphire filler, which suggested that the high aspect ratio ceramic particles formed a pathway for heat conduction through the insulating polymer matrix. The thermal diffusivity of denture base acrylic resin was increased by the addition of thermally conducting sapphire whiskers.

  20. Public acceptance: A Japanese view

    International Nuclear Information System (INIS)

    1972-01-01

    A number of factors enter into a consideration of the public acceptance of nuclear power ? the public, nuclear power as an entity, and the interaction between the two. Interaction here implies the manner in which nuclear power is presented to the public ? what is the public need for nuclear power, and what public risk is entailed in having it? The problem of public acceptance, in this sense, is time-dependent. For the public is changeable, just as nuclear power is subject to technical progress and ' social' improvement. Japan is geographically a very small country with a very high density of population. Any industrial activity and any large-scale employment of modern technology is apt to have a much greater impact on the physical, social and biological environment of individual Japanese people than similar activities would have on those of other countries. Industrial pollutants such as sulphur dioxide from power plants, oxides of nitrogen from automobile engine exhausts, organic mercury from chemical industries and so on affect society to a high degree, considered in terms of their concentration either per capita or per square kilometre. In the case of nuclear power, therefore, people are more concerned with radiological effects than with thermal pollution.no matter how one looks at it, the experience of Hiroshima and Nagasaki has made the average member of the Japanese public, very sensitive to the problem of radiation safety. This is no longer a subject in which science or logic can persuade

  1. Public acceptance: A Japanese view

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1972-07-01

    A number of factors enter into a consideration of the public acceptance of nuclear power ? the public, nuclear power as an entity, and the interaction between the two. Interaction here implies the manner in which nuclear power is presented to the public ? what is the public need for nuclear power, and what public risk is entailed in having it? The problem of public acceptance, in this sense, is time-dependent. For the public is changeable, just as nuclear power is subject to technical progress and ' social' improvement. Japan is geographically a very small country with a very high density of population. Any industrial activity and any large-scale employment of modern technology is apt to have a much greater impact on the physical, social and biological environment of individual Japanese people than similar activities would have on those of other countries. Industrial pollutants such as sulphur dioxide from power plants, oxides of nitrogen from automobile engine exhausts, organic mercury from chemical industries and so on affect society to a high degree, considered in terms of their concentration either per capita or per square kilometre. In the case of nuclear power, therefore, people are more concerned with radiological effects than with thermal pollution.no matter how one looks at it, the experience of Hiroshima and Nagasaki has made the average member of the Japanese public, very sensitive to the problem of radiation safety. This is no longer a subject in which science or logic can persuade.

  2. Operating conditions of an open and direct solar thermal Brayton cycle with optimised cavity receiver and recuperator

    International Nuclear Information System (INIS)

    Le Roux, W.G.; Bello-Ochende, T.; Meyer, J.P.

    2011-01-01

    The small-scale open and direct solar thermal Brayton cycle with recuperator has several advantages, including low cost, low operation and maintenance costs and it is highly recommended. The main disadvantages of this cycle are the pressure losses in the recuperator and receiver, turbomachine efficiencies and recuperator effectiveness, which limit the net power output of such a system. The irreversibilities of the solar thermal Brayton cycle are mainly due to heat transfer across a finite temperature difference and fluid friction. In this paper, thermodynamic optimisation is applied to concentrate on these disadvantages in order to optimise the receiver and recuperator and to maximise the net power output of the system at various steady-state conditions, limited to various constraints. The effects of wind, receiver inclination, rim angle, atmospheric temperature and pressure, recuperator height, solar irradiance and concentration ratio on the optimum geometries and performance were investigated. The dynamic trajectory optimisation method was applied. Operating points of a standard micro-turbine operating at its highest compressor efficiency and a parabolic dish concentrator diameter of 16 m were considered. The optimum geometries, minimum irreversibility rates and maximum receiver surface temperatures of the optimised systems are shown. For an environment with specific conditions and constraints, there exists an optimum receiver and recuperator geometry so that the system produces maximum net power output. -- Highlights: → Optimum geometries exist such that the system produces maximum net power output. → Optimum operating conditions are shown. → Minimum irreversibility rates and minimum entropy generation rates are shown. → Net power output was described in terms of total entropy generation rate. → Effects such as wind, recuperator height and irradiance were investigated.

  3. A development approach for nuclear thermal propulsion

    International Nuclear Information System (INIS)

    Buden, D.

    1992-01-01

    The cost and time to develop nuclear thermal propulsion systems are very approach dependent. The objectives addressed are the development of an ''acceptable'' nuclear thermal propulsion system that can be used as part of the transportation system for people to explore Mars and the enhancement performance of other missions, within highly constrained budgets and schedules. To accomplish this, it was necessary to identify the cost drivers considering mission parameters, safety of the crew, mission success, facility availability and time and cost to construct new facilities, qualification criteria, status of technologies, management structure, and use of such system engineering techniques as concurrent engineering

  4. Definition of acceptance criteria for the ITER divertor plasma-facing components through systematic experimental analysis

    International Nuclear Information System (INIS)

    Escourbiac, F; Richou, M; Guigon, R; Durocher, A; Schlosser, J; Grosman, A; Constans, S; Merola, M; Riccardi, B

    2009-01-01

    Experience has shown that a critical part of the high-heat flux (HHF) plasma-facing component (PFC) is the armour to heat sink bond. An experimental study was performed in order to define acceptance criteria with regards to thermal hydraulics and fatigue performance of the International Thermonuclear Experimental Reactor (ITER) divertor PFCs. This study, which includes the manufacturing of samples with calibrated artificial defects relevant to the divertor design, is reported in this paper. In particular, it was concluded that defects detectable with non-destructive examination (NDE) techniques appeared to be acceptable during HHF experiments relevant to heat fluxes expected in the ITER divertor. On the basis of these results, a set of acceptance criteria was proposed and applied to the European vertical target medium-size qualification prototype: 98% of the inspected carbon fibre composite (CFC) monoblocks and 100% of tungsten (W) monoblock and flat tiles elements (i.e. 80% of the full units) were declared acceptable.

  5. Definition of acceptance criteria for the ITER divertor plasma-facing components through systematic experimental analysis

    Science.gov (United States)

    Escourbiac, F.; Richou, M.; Guigon, R.; Constans, S.; Durocher, A.; Merola, M.; Schlosser, J.; Riccardi, B.; Grosman, A.

    2009-12-01

    Experience has shown that a critical part of the high-heat flux (HHF) plasma-facing component (PFC) is the armour to heat sink bond. An experimental study was performed in order to define acceptance criteria with regards to thermal hydraulics and fatigue performance of the International Thermonuclear Experimental Reactor (ITER) divertor PFCs. This study, which includes the manufacturing of samples with calibrated artificial defects relevant to the divertor design, is reported in this paper. In particular, it was concluded that defects detectable with non-destructive examination (NDE) techniques appeared to be acceptable during HHF experiments relevant to heat fluxes expected in the ITER divertor. On the basis of these results, a set of acceptance criteria was proposed and applied to the European vertical target medium-size qualification prototype: 98% of the inspected carbon fibre composite (CFC) monoblocks and 100% of tungsten (W) monoblock and flat tiles elements (i.e. 80% of the full units) were declared acceptable.

  6. Definition of acceptance criteria for the ITER divertor plasma-facing components through systematic experimental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Escourbiac, F; Richou, M; Guigon, R; Durocher, A; Schlosser, J; Grosman, A [CEA/IRFM, F-13108, Saint-Paul-lez-Durance (France); Constans, S [AREVA-NP, Le Creusot (France); Merola, M [ITER Organization, Cadarache (France); Riccardi, B [Fusion For Energy, Barcelona (Spain)], E-mail: frederic.escourbiac@cea.fr

    2009-12-15

    Experience has shown that a critical part of the high-heat flux (HHF) plasma-facing component (PFC) is the armour to heat sink bond. An experimental study was performed in order to define acceptance criteria with regards to thermal hydraulics and fatigue performance of the International Thermonuclear Experimental Reactor (ITER) divertor PFCs. This study, which includes the manufacturing of samples with calibrated artificial defects relevant to the divertor design, is reported in this paper. In particular, it was concluded that defects detectable with non-destructive examination (NDE) techniques appeared to be acceptable during HHF experiments relevant to heat fluxes expected in the ITER divertor. On the basis of these results, a set of acceptance criteria was proposed and applied to the European vertical target medium-size qualification prototype: 98% of the inspected carbon fibre composite (CFC) monoblocks and 100% of tungsten (W) monoblock and flat tiles elements (i.e. 80% of the full units) were declared acceptable.

  7. Establishment of an equivalence acceptance criterion for accelerated stability studies.

    Science.gov (United States)

    Burdick, Richard K; Sidor, Leslie

    2013-01-01

    In this article, the use of statistical equivalence testing for providing evidence of process comparability in an accelerated stability study is advocated over the use of a test of differences. The objective of such a study is to demonstrate comparability by showing that the stability profiles under nonrecommended storage conditions of two processes are equivalent. Because it is difficult at accelerated conditions to find a direct link to product specifications, and hence product safety and efficacy, an equivalence acceptance criterion is proposed that is based on the statistical concept of effect size. As with all statistical tests of equivalence, it is important to collect input from appropriate subject-matter experts when defining the acceptance criterion.

  8. Evaluation Framework and Analyses for Thermal Energy Storage Integrated with Packaged Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Kung, F.; Deru, M.; Bonnema, E.

    2013-10-01

    Few third-party guidance documents or tools are available for evaluating thermal energy storage (TES) integrated with packaged air conditioning (AC), as this type of TES is relatively new compared to TES integrated with chillers or hot water systems. To address this gap, researchers at the National Renewable Energy Laboratory conducted a project to improve the ability of potential technology adopters to evaluate TES technologies. Major project outcomes included: development of an evaluation framework to describe key metrics, methodologies, and issues to consider when assessing the performance of TES systems integrated with packaged AC; application of multiple concepts from the evaluation framework to analyze performance data from four demonstration sites; and production of a new simulation capability that enables modeling of TES integrated with packaged AC in EnergyPlus. This report includes the evaluation framework and analysis results from the project.

  9. The effect of thermal pre-treatment of titanium hydride (TiH2) powder in argon condition

    Science.gov (United States)

    Franciska P., L.; Erryani, Aprilia; Annur, Dhyah; Kartika, Ika

    2018-04-01

    Titanium hydride (TiH2) powders are used to enhance the foaming process in the formation of a highly porous metallic material with a cellular structure. But, the low temperature of hydrogen release is one of its problems. The present study, different thermal pre-treatment temperatures were employed to investigate the decomposition behavior of TiH2 to retard or delay a hydrogen gas release process during foaming. As a foaming agent, TiH2 was subjected to various heat treatments prior at 450 and 500°C during 2 hours in argon condition. To study the formation mechanism, the thermal behavior of titanium hydride and hydrogen release are investigated by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The morphology of pre-treated titanium hydride powders were examined using Scanning Electron Microscope (SEM) while unsure mapping and elemental composition of the pre-treated powders processed by Energy Dispersive Spectroscopy (EDS). To study the phase formation was characterized by X-ray diffraction analysis (XRD). In accordance with the results, an increase in pre-treatment temperature of TiH2 to higher degrees are changing the process of releasing hydrogen from titanium hydride powder. DTA/TGA results showed that thermal pre-treatment TiH2 at 450°C, released the hydrogen gas at 560°C in heat treatment when foaming process. Meanwhile, thermal pre-treatment in TiH2 at 500°C, released the hydrogen gas at 670°C when foaming process. There is plenty of direct evidence for the existence of oxide layers that showed by EDS analysis obtained in SEM. As oxygen is a light element and qualitative proof shows that the higher pre-treatment temperature produces more and thicker oxygen layers on the surface of the TiH2 powder particles. It might the thickness of oxide layer are different from different pre-treatment temperatures, which leading to the differences in the decomposition temperature. But from SEM result that oxidation of the powder does not

  10. Time perception and illness acceptance among remitting-relapsing multiple sclerosis patients under treatment.

    Science.gov (United States)

    Król, Joanna; Szcześniak, Małgorzata; Koziarska, Dorota; Rzepa, Teresa

    2015-01-01

    The aim of the study was to determine temporal orientation in patients diagnosed with RR-MS as compared with that of healthy individuals; to analyse self-evaluated acceptance levels in terms of physical and psychological condition and self-reliance; an attempt to identify factors of illness acceptance in patients with RR-MS including temporal perspective. Acceptance of Illness Scale (AIS, adapted into Polish by Z. Juczyński), Zimbardo Time Perspective Inventory (ZTPI, adapted into Polish by M. Mażewski), and original interview aimed to assess socio-demographic data and self-evaluated physical as well as psychological condition and self-reliance of patients with MS (referred to the neurological testing according to the EDSS). Patients with RR-MS focus on fatalistic and hedonistic present more than healthy individuals. They also tend to reflect on their negative past experience. Acceptance of illness correlated positively with subjective assessment of physical and psychological condition as well as self-reliance, and negatively with objective disability score (measured with the use of EDSS) and a factor considering time of disease duration. Avoiding contemplation of negative past and concentrating on hedonistic future constitute significant predictors of illness acceptance. These results may be of importance in terms of holistic approach to treatment of RR-MS patients. In the initial stage of the disease progression, patients might benefit from psychological support due to change in temporal orientation.

  11. Numerically Analysed Thermal Condition of Hearth Rollers with the Water-Cooled Shaft

    Directory of Open Access Journals (Sweden)

    A. V. Ivanov

    2016-01-01

    rollers without insulation. Insulation (screens or bulk insulation between the shaft and the barrel of roller allows reducing the cooling water losses. A comparative analysis of research results allowed us to find that operating conditions of the furnace rolls with screen insulation are more favorable in terms of thermal conditions and losses, than those of rollers without the insulation and rollers with the bulk insulation.

  12. Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation

    Directory of Open Access Journals (Sweden)

    Mohamad Irfan Fathurrohman

    2015-07-01

    Full Text Available The vulcanization kinetics of Ethylene-propylene diene monomer (EPDM rubber thermal insulation was studied by using rheometer under isothermal condition at different temperatures. The rheometry analysis was used to determining the cure kinetic parameters and predicting the cure time of EPDM thermal insulation. The experimental results revealed that the curing curves of EPDM thermal insulation were marching and the optimum curing time decreased with increasing the temperature. The kinetic parameters were determined from the autocatalytic model showed close fitting with the experimental results, indicating suitability of autocatalytic model in characterizing the cure kinetics. The activation energy was determined from the autocatalytic model is 46.3661 kJ mol-1. The cure time were predicted from autocatalytic model and the obtained kinetic parameter by using the relationship among degree of conversion, cure temperature, and cure time. The predictions of cure time provide information for the actual curing characteristic of EPDM thermal insulation. The mechanical properties of EPDM thermal insulation with different vulcanization temperatures showed the same hardness, tensile strength and modulus at 300%, except at temperature 70 °C, while the elongation at breaking point decreased with increasing temperature of vulcanization. © 2015 BCREC UNDIP. All rights reservedReceived: 8th April 2014; Revised: 7th January 2015; Accepted: 16th January 2015How to Cite: Fathurrohman, M.I., Maspanger, D.R., Sutrisno, S. (2015. Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation. Bulletin of Chemi-cal Reaction Engineering & Catalysis, 10 (2, 104-110. (doi:10.9767/bcrec.10.2.6682.104-110Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.6682.104-110 

  13. K-West and K-East basin thermal analyses for dry conditions

    International Nuclear Information System (INIS)

    Beaver, T.R.; Cramer, E.R.; Hinman, C.A.

    1994-01-01

    Detailed 3 dimensional thermal analyses of the 100K East and 100 K West basins were conducted to determine the peak fuel temperature for intact fuel in the event of a complete loss of water from the basins. Thermal models for the building, an array of fuel encapsulation canisters on the basin floor, and the fuel within a single canister are described along with conservative predictions for the maximum expected temperatures for the loss of water event

  14. Using a modified technology acceptance model in hospitals.

    Science.gov (United States)

    Aggelidis, Vassilios P; Chatzoglou, Prodromos D

    2009-02-01

    The use of information technology in the health care sector and especially in hospitals offers great potential for improving the quality of services provided and the efficiency and effectiveness of the personnel, but also for reducing the organizational expenses. However, the main question that arises according to the literature is whether hospital personnel are willing to use state of the art information technology while performing their tasks. This study attempts to address this issue by developing and testing a modified technology acceptance model taking into consideration other relevant models found in the literature. The original TAM has been extended to include some exogenous variables in order to examine HIS acceptance by Greek hospital personnel. Correlation, explanatory and confirmation factor analysis was performed to test the reliability and validity of the measurement model. The structural equation modeling technique has also been used to evaluate the causal model. The results indicate that perceived usefulness, ease of use, social influence, attitude, facilitating conditions and self-efficacy significantly affect hospital personnel behavioral intention. Training has a strong indirect impact on behavioral intention through the mediators of facilitating condition and ease of use. Furthermore, the existence of significant positive effects between self-efficacy and social influence, perceived usefulness and anxiety, and facilitating conditions and social influence is also supported. The proposed model can explain 87% of the variance of behavioral intention indicating that the core constructs of the technology acceptance models have a strong and statistically significant influence on hospital personnel usage intention.

  15. Acceptability of the rainwater harvesting system to the slum dwellers of Dhaka City.

    Science.gov (United States)

    Islam, M M; Chou, F N-F; Kabir, M R

    2010-01-01

    Urban area like Dhaka City, in Bangladesh, has scarcity of safe drinking water which is one of the prominent basic needs for human kind. This study explored the acceptability of harvested rainwater in a densely populated city like Dhaka, using a simple and low cost technology. A total of 200 random people from four slums of water-scarce Dhaka City were surveyed to determine the dwellers' perception on rainwater and its acceptability as a source of drinking water. The questionnaire was aimed at finding the socio-economic condition and the information on family housing, sanitation, health, existing water supply condition, knowledge about rainwater, willingness to accept rainwater as a drinking source etc. A Yield before Spillage (YBS) model was developed to know the actual rainwater availability and storage conditions which were used to justify the effective tank size. Cost-benefit analysis and feasibility analysis were performed using the survey results and the research findings. The survey result and overall study found that the low cost rainwater harvesting technique was acceptable to the slum dwellers as only the potential alternative source of safe drinking water.

  16. Perceptual-Semantic Congruency Facilitates Semantic Discrimination of Thermal Qualities

    Directory of Open Access Journals (Sweden)

    Yizhen Zhou

    2017-12-01

    Full Text Available The ability to sense temperature is vital to our life. It signals the environmental condition, reflects the physiological conditions of our own body, and generates feelings of pleasantness or unpleasantness. Moreover, recent studies have demonstrated implicit associations between physical temperature and social/emotional concepts, suggesting the processing of temperature may even influence cognition. In this work, we examined the effect of physical warmth and coldness on semantic cognition. Participants performed speeded target categorization for thermal descriptors in the form of semantic words or illustrative figures representing the thermal qualities “warm” or “cold” while physical thermal stimulation was presented. We compared the average reaction time (RT for the congruent and incongruent conditions managed by response key assignments. In the congruent condition, the response key for the symbol associated with warmth (coldness was assigned to the hand with warm (cold thermal stimulation, and in the incongruent condition the key assignment was reversed. Our results demonstrate that the average RT in the congruent condition was faster than in the incongruent one for both forms of thermal descriptors, suggesting that the experience of physical temperature facilitates the internal processing of the meaning of thermal quality.

  17. The influence of variable operating conditions on the design and exploitation of fly ash pneumatic transport systems in thermal power plants

    Directory of Open Access Journals (Sweden)

    M. Stanojević

    2008-12-01

    Full Text Available The efficiency of an air-slide pneumatic conveying system depends, first of all, on several basic elements chosen or calculated during the design of a plant: air-slide design parameters, air mover characteristics, as well as the physical and chemical properties of the material to be transported. However, during the exploitation of this type of system which is used for handling ash in thermal-power plants, either gradual and/or sudden changes in the operating conditions can arise. This may be due to changes both in the proportion of ash content, and in the flow characteristics of the porous membrane. The consequences of changes in these conditions on the performance of the ash handling system are analyzed, based upon the results of the experimental work carried out on the test rig at the Faculty of Mechanical Engineering in Belgrade, and upon the on-site measurements at the thermal-power plant "Nikola Tesla B".

  18. The influence of variable operating conditions on the design and exploitation of fly ash pneumatic transport systems in thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Stanojevic, M.; Radic, D.; Jovovic, A. (and others) [University of Belgrade, Belgrade (Serbia). Dept. of Processing Engineering

    2008-10-15

    The efficiency of an air-slide pneumatic conveying system depends, first of all, on several basic elements chosen or calculated during the design of a plant: air-slide design parameters, air mover characteristics, as well as the physical and chemical properties of the material to be transported. However, during the exploitation of this type of system which is used for handling ash in thermal-power plants, either gradual and/or sudden changes in the operating conditions can arise. This may be due to changes both in the proportion of ash content and in the flow characteristics of the porous membrane. The consequences of changes in these conditions on the performance of the ash handling system are analyzed, based upon the results of the experimental work carried out on the test rig at the Faculty of Mechanical Engineering in Belgrade, and upon the on-site measurements at the thermal-power plant 'Nikola Tesla B'. 5 refs., 8 figs., 4 tabs.

  19. Outdoor thermal comfort.

    Science.gov (United States)

    Nikolopoulou, Marialena

    2011-06-01

    A review of the various approaches in understanding outdoor thermal comfort is presented. The emphasis on field surveys from around the world, particularly across Europe, enables us to understand thermal perception and evaluate outdoor thermal comfort conditions. The consistent low correlations between objective microclimatic variables, subjective thermal sensation and comfort outdoors, internationally, suggest that thermophysiology alone does not adequate describe these relationships. Focusing on the concept of adaptation, it tries to explain how this influences outdoor comfort, enabling us to inhabit and get satisfaction from outdoor spaces throughout the year. Beyond acclimatization and behavioral adaptation, through adjustments in clothing and changes to the metabolic heat, psychological adaptation plays a critical role to ensure thermal comfort and satisfaction with the outdoor environment. Such parameters include recent experiences and expectations; personal choice and perceived control, more important than whether that control is actually exercised; and the need for positive environmental stimulation suggesting that thermal neutrality is not a pre-requisite for thermal comfort. Ultimately, enhancing environmental diversity can influence thermal perception and experience of open spaces.

  20. Factors influencing nurses' acceptance of hospital information systems in Iran: application of the Unified Theory of Acceptance and Use of Technology.

    Science.gov (United States)

    Sharifian, Roxana; Askarian, Fatemeh; Nematolahi, Mohtaram; Farhadi, Payam

    User acceptance is a precondition for successful implementation of hospital information systems (HISs). Increasing investment in information technology by healthcare organisations internationally has made user acceptance an important issue in technology implementation and management. Despite the increased focus on hospital information systems, there continues to be user resistance. The present study aimed to investigate the factors affecting hospital information systems nurse-user acceptance of HISs, based on the Unified Theory of Acceptance and Use of Technology (UTAUT), in the Shiraz University of Medical Sciences teaching hospitals. A descriptive-analytical research design was employed to study nurses' adoption and use of HISs. Data collection was undertaken using a cross-sectional survey of nurses (n=303). The research model was examined using the LISREL path confirmatory modeling. The results demonstrated that the nurses' behavioural intention (BI) to use hospital information systems was predicted by Performance Expectancy (PE) (β= 2.34, pExpectancy (EE) (β= 2.21, pexpectancy, effort expectancy, social influence and facilitating conditions, with performance expectancy having the strongest effect on user intention.