WorldWideScience

Sample records for activation decay heat

  1. Evaluation of induced activity, decay heat and dose rate distribution after shutdown in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Maki, Koichi [Hitachi Ltd., Ibaraki (Japan). Hitachi Research Lab.; Satoh, Satoshi; Hayashi, Katsumi; Yamada, Koubun; Takatsu, Hideyuki; Iida, Hiromasa

    1997-03-01

    Induced activity, decay heat and dose rate distributions after shutdown were estimated for 1MWa/m{sup 2} operation in ITER. The activity in the inboard blanket one day after shutdown is 1.5x10{sup 11}Bq/cm{sup 3}, and the average decay heating rate 0.01w/cm{sup 3}. The dose rate outside the 120cm thick concrete biological shield is two order higher than the design criterion of 5{mu}Sv/h. This indicates that the biological shield thickness should be enhanced by 50cm in concrete, that is, total thickness 170cm for workers to enter the reactor room and to perform maintenance. (author)

  2. THIDA-2: an advanced code system for calculation of transmutation, activation, decay heat and dose rate

    International Nuclear Information System (INIS)

    In a D-T burning fusion reactor, the radioactivity induced by the 14 MeV neutrons causes many problems. It limits personnel access to the reactor during shutdown, generates decay heat and produces radwastes. A code system THIDA had been developed in 1978 to calculate the radioactivity and dose rate around a fusion device. The THIDA system consisted of the followings: one- and two-dimensional discrete ordinates radiation transport codes; induced activity calculation code; three libraries for transmutation and decay chain data, transmutation cross sections and delayed gamma-ray emission data. The present report gives a complete description of THIDA-2, a new advanced version of the THIDA system which has the following major improvements: 1. Capability to treat three-dimensional calculation models by the use of a Monte Carlo transport code. 2. Accurate decay heat calculation following the transport of delayed gamma rays. 3. Simplification of the data input process by the use of free format scheme and closer coupling between the radiation transport codes and the induced activity calculation code. 4. Self-descriptive output format and additional plotter output. 5. Capability to calculate problems requiring larger core memory by the use of variable dimension. (author)

  3. Benchmarking of Decay Heat Measured Values of ITER Materials Induced by 14 MeV Neutron Activation with Calculated Results by ACAB Activation Code

    Energy Technology Data Exchange (ETDEWEB)

    Tore, C.; Ortego, P.; Rodriguez Rivada, A.

    2014-07-01

    The aim of this paper is the comparison between the calculated and measured decay heat of material samples which were irradiated at the Fusion Neutron Source of JAERI in Japan with D-T production of 14MeV neutrons. In the International Thermonuclear Experimental Reactor (ITER) neutron activation of the structural material will result in a source of heat after shutdown of the reactor. The estimation of decay heat value with qualified codes and nuclear data is an important parameter for the safety analyses of fusion reactors against lost of coolant accidents. When a loss of coolant and/or flow accident happen plasma facing components are heated up by decay heat. If the temperature of the components exceeds the allowable temperature, the accident would expand to loose the integrity of ITER. Uncertainties associated with decay prediction less than 15% are strongly requested by the ITER designers. Additionally, accurate decay heat prediction is required for making reasonable shutdown scenarios of ITER. (Author)

  4. Material composition and nuclear data libraries' influence on nickel-chromium alloys activation evaluation: a comparison with decay heat experiments

    International Nuclear Information System (INIS)

    The paper presents the activation analyses on Inconel-600 nickel-chromium alloy. Three activation data libraries, namely the EAF-4.1, the EAF-97 and the FENDL/A-2, and the FENDL/D-2 decay data library, have been used to perform the calculation with the European activation code ANITA-4/M. The neutron flux distribution into the material samples was provided by JAERI as results of 3D Monte-Carlo MCNP transport code experiment simulation. A comparison with integral decay heat measurement performed at the Fusion Neutronics Source (FNS), JAERI, Tokai, Japan, is used to validate the computational approach. The calculation results are given and discussed. The impact of the material composition, including impurities, on the decay heat of samples irradiated in fusion-like neutron spectra is assessed and discussed. The discrepancies calculations-experiments are within the experimental errors, that is between 6% and 10%, except for the short cooling times (less than 40 min after the end of irradiation). To improve calculation consistency with the experimental results, the knowledge of the material impurities content is mandatory

  5. Material composition and nuclear data libraries' influence on nickel-chromium alloys activation evaluation: a comparison with decay heat experiments

    CERN Document Server

    Cepraga, D G

    2000-01-01

    The paper presents the activation analyses on Inconel-600 nickel-chromium alloy. Three activation data libraries, namely the EAF-4.1, the EAF-97 and the FENDL/A-2, and the FENDL/D-2 decay data library, have been used to perform the calculation with the European activation code ANITA-4/M. The neutron flux distribution into the material samples was provided by JAERI as results of 3D Monte-Carlo MCNP transport code experiment simulation. A comparison with integral decay heat measurement performed at the Fusion Neutronics Source (FNS), JAERI, Tokai, Japan, is used to validate the computational approach. The calculation results are given and discussed. The impact of the material composition, including impurities, on the decay heat of samples irradiated in fusion-like neutron spectra is assessed and discussed. The discrepancies calculations-experiments are within the experimental errors, that is between 6% and 10%, except for the short cooling times (less than 40 min after the end of irradiation). To improve calcul...

  6. Decay Heat Removal System of Monju

    International Nuclear Information System (INIS)

    MONJU has three decay heat removal systems. The intermediate heat exchanger of the decay heat removal system is incorporated within the main IHX shell, and the heat from the secondary system is rejected to the air. Forced circulation is adopted for both primary and secondary coolant, though natural circulation capability is designed into the plant itself. Feasibility of rejecting the decay heat through steam plant is also being studied. In this paper, MONJU's decay heat removal system design, operational procedures, and the considerations behind the concept will be presented. (author)

  7. Heat Transfer Characteristics of SiC-coated Heat Pipe for Passive Decay Heat Removal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Mo; Kim, In Guk; Jeong, Yeong Shin; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-10-15

    The main concern with the Fukushima accident was the failure of active and passive core cooling systems. The main function of existing passive decay heat removal systems is feeding additional coolant to the reactor core. Thus, an established emergency core cooling system (ECCS) cannot operate properly because of impossible depressurization under the station blackout (SBO) condition. Therefore, a new concept for passive decay heat removal system is required. In this study, an innovative hybrid control rod concept is considered for passive in-core decay heat removal that differs from the existing direct vessel injection core cooling system and passive auxiliary feedwater system (PAFS). The heat transfer between the evaporator and condenser sections occurs by phase change of the working fluid and capillary action induced by wick structures installed on the inner wall of the heat pipe. In this study, a hybrid control rod is developed to take the roles of both neutron absorption and heat removal by combining the functions of a heat pipe and control rod. Previous studies on enhancing the heat removal capacity of heat pipes used nanofluids, self-rewetting fluids, various wick structures and condensers. Many studies have examined the thermal performances of heat pipes using various nanofluids. They concluded that the enhanced thermal performance of the heat pipe using nanofluids is due to nanoparticle deposition on the wick structures. Thus, the wick structure of heat pipes has been modified by nanoparticle deposition to enhance the heat removal capacity. However, previous studies used relatively small heat pipes and narrow ranges of heat loads. The environment of a nuclear reactor is very specific, and the decay heat produced by fission products after shutdown is relatively large. Thus, this study tested a large-scale heat pipe over a wide range of power. The concept of a hybrid heat pipe for an advanced in-core decay heat removal system was introduced for complete

  8. Development of limiting decay heat values

    International Nuclear Information System (INIS)

    A number of tools are used in the assessment of decay heat during an outage of the CANDU-6. Currently, the technical basis for all of these tools is 'CANDU Channel Decay Power', Reference 1. The methods used in that document were limited to channel decay powers. However, for most outage support analysis, decay heat limits are based on bundle heats. Since the production of that document in 1977, new versions of codes, and updates of general-purpose and CANDU-specific libraries have become available. These tools and libraries have both a more formal technical basis than Reference 1, and also a more formal validation base. Using these tools it is now possible to derive decay heat with more specific input parameters, such as fuel composition, heat per unit of fuel, and irradiation history, and to assign systematically derived uncertainty allowances to such decay heat values. In particular, we sought to examine a broad range of likely bundle histories, and thus establish a set of limiting bundle decay beat values, that could serve as a bounding envelope for use in Nuclear Safety Analysis. (author)

  9. Decay heat studies for nuclear energy

    Science.gov (United States)

    Algora, A.; Jordan, D.; Taín, J. L.; Rubio, B.; Agramunt, J.; Caballero, L.; Nácher, E.; Perez-Cerdan, A. B.; Molina, F.; Estevez, E.; Valencia, E.; Krasznahorkay, A.; Hunyadi, M. D.; Gulyás, J.; Vitéz, A.; Csatlós, M.; Csige, L.; Eronen, T.; Rissanen, J.; Saastamoinen, A.; Moore, I. D.; Penttilä, H.; Kolhinen, V. S.; Burkard, K.; Hüller, W.; Batist, L.; Gelletly, W.; Nichols, A. L.; Yoshida, T.; Sonzogni, A. A.; Peräjärvi, K.

    2014-01-01

    The energy associated with the decay of fission products plays an important role in the estimation of the amount of heat released by nuclear fuel in reactors. In this article we present results of the study of the beta decay of some refractory isotopes that were considered important contributors to the decay heat in reactors. The measurements were performed at the IGISOL facility of the University of Jyväskylä, Finland. In these studies we have combined for the first time a Penning trap (JYFLTRAP), which was used as a high resolution isobaric separator, with a total absorption spectrometer. The results of the measurements as well as their consequences for decay heat summation calculations are discussed.

  10. Assessment of the activation, decay heat, and waste disposal of the US helium-cooled ceramic breeder test blanket module in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Youssef, Mahmoud Z. [University of California-Los Angeles, Los Angeles, CA 90025 (United States); University of Wisconsin-Madison (United States)], E-mail: youssef@fusion.ucla.edu; Ying, Alice [University of California-Los Angeles, Los Angeles, CA 90025 (United States)

    2008-12-15

    The radioactivity inventory and decay heat in the US helium-cooled ceramic breeder (HCCB) test blanket module (TBM) have been assessed at shutdown and for several times thereafter. The sub-module will have its own FW and structural container box that houses the breeder and beryllium pebble bed units, arranged in an edge-on-configuration. Low activation ferritic steel (F82H) is used as the structure and helium is used as a coolant. The breeder beds are made of Li{sub 2}TiO{sub 3} pebbles in which lithium has been enriched up to 75% in Li-6. Pulsed operation mode is assumed. During operation in the D-T phase, the total heating rate in the TBM is {approx}263 kW. The total amount of tritium generated in the breeder and the beryllium multiplier is {approx}9 g and 0.07 g, respectively, after reaching the 0.3 MWa/m{sup 2} fluence limit. At shutdown, the total radioactivity and decay heat levels are {approx}0.89 MCi and {approx}0.002 MW, respectively. These values drop sharply after 1 min to {approx}0.098 MCi and {approx}0.0006 MW. The contribution from the F82H structure is the dominant one up to {approx}10 years following shutdown. After {approx}10 years, the contribution to the total activation and decay heat from the breeder material is the dominant one due to the generated tritium. The WDR of various components are far below unity and thus are well within ITER regulatory guidelines.

  11. Fission product decay heat for thermal reactors

    Energy Technology Data Exchange (ETDEWEB)

    Dickens, J. K.

    1979-01-01

    In the past five years there have been new experimental programs to measure decay heat (i.e., time dependent beta- plus gamma-ray energy release rates from the decay of fission products) following thermal-neutron fission of /sup 235/U, /sup 239/Pu, and /sup 241/Pu for times after fission between 1 and approx. 10/sup 5/ sec. Experimental results from the ORNL program stress the very short times following fission, particularly in the first few hundred sec. Complementing the experimental effort, computer codes have been developed for the computation of decay heat by summation of calculated individual energies released by each one of the fission products. By suitably combining the results of the summation calculations with the recent experimental results, a new Decay Heat Standard has been developed for application to safety analysis of operations of light water reactors. The new standard indicates somewhat smaller energy release rates than those being used at present, and the overall uncertainties assigned to the new standard are much smaller than those being used at present.

  12. Applications of TAGS data in beta decay energies and decay heat calculations

    OpenAIRE

    Pham, N. S.; 片倉 純一

    2007-01-01

    The recent data of beta-decay intensity measured by using the total absorption gamma-ray spectrometer (TAGS), for several fission products (FP), has been applied for calculations of the average energies and spectra, and decay heat summations. The calculations were performed based on the Gross theory of beta decay, in which the beta strength functions were experimentally derived from TAGS data. The deviations of decay heat power predictions from the original decay data of JENDL Decay Data File...

  13. Jeff-3 and decay heat calculations

    International Nuclear Information System (INIS)

    The decay heat power, i.e. the residual heat generated by irradiated nuclear fuels, is a significant parameter to define the power of a reactor. A good evaluation of this power depends both on the accuracy of the processing algorithm and on the quality of the physical data used. This report describes the steps carried out, ranging from tests of consistency to the validation by calculations - experiments comparisons, allowing to choose the validated nuclear data. We have compared the Jeff-3 evaluation (only the file 8 containing decay data) with the Jeff-2.2 and Endf/B7.O evaluations through the computation of residual power. It appears that the residual powers computed by the DARWIN code from Jeff-3.1.1 data for short times agree more with experimental data. There is a slight discrepancy (∼ 2%) between Jeff-3.1 and Jeff-3.1.1 on the total residual power computed for PWR UO2 fuel. For long decay times the discrepancy is more significant between Jeff-3.1.1 and Jeff-2 on the computation of detailed residual powers because some prevailing isotopes have more formation channels taken into account in Jeff-3 and Jeff-3.1.1 than in Jeff-2

  14. Decay heat experiment and validation of calculation code systems for fusion reactor

    International Nuclear Information System (INIS)

    Although accurate estimation of decay heat value is essential for safety analyses of fusion reactors against loss of coolant accidents and so on, no experimental work has been devoted to validating the estimation. Hence, a decay heat measurement experiment was performed as a task (T-339) of ITER/EDA. A new detector, the Whole Energy Absorption Spectrometer (WEAS), was developed for accurate and efficient measurements of decay heat. Decay heat produced in the thirty-two sample materials which were irradiated by 14-MeV neutrons at FNS/JAERI were measured with WEAS for a wide cooling time period from 1 min to 400 days. The data presently obtained were the first experimental decay heat data in the field of fusion. Validity of decay heat calculation codes of ACT4 and CINAC-V4, activation cross section libraries of FENDL/A-2.0 and JENDL Activation File, and decay data was investigated through analyses of the experiment. As a result, several points that should be modified were found in the codes and data. After solving the problems, it was demonstrated that decay heat valued calculated for most of samples were in good agreement with the experimental data. Especially for stainless steel 316 and copper, which were important materials for ITER, decay heat could be predicted with accuracy of ±10%. (author)

  15. Decay heat experiment and validation of calculation code systems for fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Fujio; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Wada, Masayuki

    1999-10-01

    Although accurate estimation of decay heat value is essential for safety analyses of fusion reactors against loss of coolant accidents and so on, no experimental work has been devoted to validating the estimation. Hence, a decay heat measurement experiment was performed as a task (T-339) of ITER/EDA. A new detector, the Whole Energy Absorption Spectrometer (WEAS), was developed for accurate and efficient measurements of decay heat. Decay heat produced in the thirty-two sample materials which were irradiated by 14-MeV neutrons at FNS/JAERI were measured with WEAS for a wide cooling time period from 1 min to 400 days. The data presently obtained were the first experimental decay heat data in the field of fusion. Validity of decay heat calculation codes of ACT4 and CINAC-V4, activation cross section libraries of FENDL/A-2.0 and JENDL Activation File, and decay data was investigated through analyses of the experiment. As a result, several points that should be modified were found in the codes and data. After solving the problems, it was demonstrated that decay heat valued calculated for most of samples were in good agreement with the experimental data. Especially for stainless steel 316 and copper, which were important materials for ITER, decay heat could be predicted with accuracy of {+-}10%. (author)

  16. Assessment of the activation, decay heat, and waste disposal of the US helium-cooled ceramic breeder test blanket module in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Youssef, M.; Ying, A. [California Univ., Los Angeles, CA (United States)

    2007-07-01

    The radioactivity inventory and after heat in the U.S. helium-cooled ceramic breeder (HCCB) test blanket module (TBM) have been accessed at shut down and for several times thereafter. Also assessed is the waste disposal rating (WDR) of its various components. The objectives are: (1) to provide the information needed for further safety assessment of the generated radionuclides and their volatility, as well as after heat on the safety operation of ITER, and (2) to aid in determining the waiting cooling period prior to removing and transporting the TBM for further treatment outside ITER site. The TBM is proposed to be placed in one of the three dedicated test ports of ITER. The current proposal is that it will occupy 1/3 of the horizontal upper half of a port next to Japan and Korea sub-modules. The sub-module will have its own FW and structural container box that houses the breeder and beryllium pebble bed units, arranged in an edge-on-configuration. Helium is used to cool the FW, sides of the box, and the internal plates. Conventional ferritic steel (F82H) is used as the structure. The sub-module has 71 cm height, 38.9 cm wide and 60 cm depth in the radial direction. The breeder beds are made of Li{sub 2}TiO{sub 3} pebbles with 94% theoretical density and 62% packing factor (as the beryllium pebbles). Lithium-6 is enriched to 75%. A 2 mm thick beryllium layer is used as a plasma facing material on the FW area subjected to 0.78 MW/m{sup 2} neutron wall load. Pulsed operation mode is assumed. Each pulse is assumed to be 400 s full flat top followed by 1800 s dwell time, during which the decay of the generated radionuclides are accounted for. The 500 MW pulses are assumed to be generated one after another until a fluence limit of 0.3 MWa/m{sup 2} is reached without replacing the TBM. This gives upper conservative estimates for the radioactive inventory and decay heat. During operation in the D-T phase, the total heating rate in the TBM is {proportional_to}263 KW. The

  17. Experimental Investigation on Decay Heat Removal System of CEFR

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The decay heat exists in a relative long time period after reactor shut down. The decay heat is removed by the decay heat removal system (DHRS).The manager of CEFR demanded that experiments should be carried out to make sure that natural circulation could be established under the conditions of < 1.0 percent of the normal power. Experiments are therefore performed under the heating power of 2, 3, 4, 6 and 8.5 kW respectively. The measured temperature in the hot plenum will be used to validate the computer codes. Moreover,

  18. CFD Analysis of a Hybrid Heat Pipe for In-Core Passive Decay Heat Removal System

    Energy Technology Data Exchange (ETDEWEB)

    Jeong Yeong Shin; Kim, Kyung Mo; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-05-15

    Station blackout (SBO) accident is the event that all AC power is totally lost from the failure of offsite and onsite power sources. Although electricity was provided from installed batteries for active system after shutdown, they were failed due to flooding after tsunami. The vulnerability of the current operating power plant's cooling ability during extended station blackout events is demonstrated and the importance of passive system becomes emphasized. Numerous researches about passive system have been studied for proper cooling residual heat after Fukushima nuclear power plant accident. Heat pipe is the effective passive heat transfer device that latent heat of vaporization is used to transport heat over long distance with even small temperature difference. Since liquid flows due to capillary force from wick structure and steam flows up due to buoyancy force, power is not necessary. Heat pipe is widely used in removal of local hot spot heat fluxes in CPU and thermal management in space crafts and satellites. Hybrid control rod, which consists of heat pipe with B{sub 4}C for wick structure material can be used for removing residual heat after. It can be applied to both for shutdown and cooling of decay heat in reactor. This concept is independent of external reactor situation like operator's mistake or malfunction of active cooling system. Heat pipe cooling system can be applied to Emergency Core Cooling System, In-Vessel Retention, containment and spent fuel cooling, contributing to decrease Core Damage Frequency.

  19. Consistency among integral measurements of aggregate decay heat power

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, H.; Sagisaka, M.; Oyamatsu, K.; Kukita, Y. [Nagoya Univ. (Japan)

    1998-03-01

    Persisting discrepancies between summation calculations and integral measurements force us to assume large uncertainties in the recommended decay heat power. In this paper, we develop a hybrid method to calculate the decay heat power of a fissioning system from those of different fissioning systems. Then, this method is applied to examine consistency among measured decay heat powers of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U and {sup 239}Pu at YAYOI. The consistency among the measured values are found to be satisfied for the {beta} component and fairly well for the {gamma} component, except for cooling times longer than 4000 s. (author)

  20. Decay heat calculation an international nuclear code comparison

    International Nuclear Information System (INIS)

    The results of an international code comparison on decay heat are presented and discussed. Participants from more than ten laboratories calculated, using the same input data, decay heat for thirteen cooling times between 1 and 1013 sec. Two irradiation cases were proposed: fission pulse and 3x107 seconds of irradiation of 235U fuel. The results are analysed and compared. This inter-comparison shows that, if the same input data are given, most of the codes give very similar results for the decay heat and consequently also for the fission product contribution

  1. LWR decay heat calculations using a GRS improved ENDF/B-6 based ORIGEN data library

    Energy Technology Data Exchange (ETDEWEB)

    Hesse, U.; Hummelsheim, K.I.; Kilger, R.; Moser, F.E.; Langenbuch, S. [Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS) mbH, Forschungsinstitute, Garching (Germany)

    2008-07-01

    The known ORNL ORIGEN code is widely spread over the world for inventory, activity and decay heat tasks and is used stand-alone or implemented in activation, shielding or burn-up systems. More than 1000 isotopes with more than six coupled neutron capture and radioactive decay channels are handled simultaneously by the code. The characteristics of the calculated inventories, e.g., masses, activities, neutron and photon source terms or the decay heat during short or long decay time steps are achieved by summing over all isotopes, characterized in the ORIGEN libraries. An extended nuclear GRS-ORIGENX data library is now developed for practical appliance. The library was checked for activation tasks of structure material isotopes and for actinide and fission product burn-up calculations compared with experiments and standard methods. The paper is directed to the LWR decay heat calculation features of the new library and shows the differences of dynamical and time integrated results of Endf/B-6 based and older Endf/B-5 based libraries for decay heat tasks compared to fission burst experiments, ANS curves and some other published data. A multi-group time exponential evaluation is given for the fission burst power of {sup 235}U, {sup 238}U, {sup 239}Pu and {sup 241}Pu, to be used in quick LWR reactor accident decay heat calculation tools. (authors)

  2. Decay heat measurement of fusion related materials in an ITER-like neutron field

    Science.gov (United States)

    Morimoto, Y.; Ochiai, K.; Maekawa, F.; Wada, M.; Nishitani, T.; Takeuchi, H.

    2002-12-01

    Decay heat is one of the most important factors for the safety aspect of ITER. Especially, the prediction of decay heat with an uncertainty less than 15% for the three most important materials, i.e., copper, type-316 stainless steel (SS316) and tungsten, is strongly requested by designers of ITER. To provide experimental decay heat data needed for validation of decay heat calculations for SS316 and copper, an experiment was conducted as the ITER/EDA task T-426. An ITER-like neutron field was constructed, and decay heat source distributions in thick copper and SS316 plates were measured with the whole energy absorption spectrometer. The measured decay heat distributions in the thick sample plates were compared with the predicted values by MCNP calculations. It was found that the use of an effective activation cross-section calculated by MCNP was needed to consider the self-shielding effects and, for both cases, MCNP calculations could predict the decay heat adequately.

  3. Proliferation resistance of plutonium based on decay heat

    International Nuclear Information System (INIS)

    Proliferation resistance of plutonium can be enhanced by increasing the decay heat of plutonium. For example, it can be enhanced by increasing the isotopic fraction of 238Pu, which has the largest decay heat among plutonium isotopes, produced by transmutation of Minor Actinides (Protected Plutonium Production: P3). In the present paper, proliferation resistance of plutonium was evaluated based on decay heat with physical assessment model. As a summary of the evaluation, new criteria to evaluate proliferation resistance of plutonium based on its isotopic composition from the view point of decay heat were suggested. The present methodology and the criteria were applied to evaluate the impact of P3 by the transmutation of Minor Actinides in fast breeder reactor blanket on proliferation resistance of plutonium. (author)

  4. Gas-Cooled Fast Reactor (GFR) Decay Heat Removal Concepts

    Energy Technology Data Exchange (ETDEWEB)

    K. D. Weaver; L-Y. Cheng; H. Ludewig; J. Jo

    2005-09-01

    Current research and development on the Gas-Cooled Fast Reactor (GFR) has focused on the design of safety systems that will remove the decay heat during accident conditions, ion irradiations of candidate ceramic materials, joining studies of oxide dispersion strengthened alloys; and within the Advanced Fuel Cycle Initiative (AFCI) the fabrication of carbide fuels and ceramic fuel matrix materials, development of non-halide precursor low density and high density ceramic coatings, and neutron irradiation of candidate ceramic fuel matrix and metallic materials. The vast majority of this work has focused on the reference design for the GFR: a helium-cooled, direct power conversion system that will operate with an outlet temperature of 850ºC at 7 MPa. In addition to the work being performed in the United States, seven international partners under the Generation IV International Forum (GIF) have identified their interest in participating in research related to the development of the GFR. These are Euratom (European Commission), France, Japan, South Africa, South Korea, Switzerland, and the United Kingdom. Of these, Euratom (including the United Kingdom), France, and Japan have active research activities with respect to the GFR. The research includes GFR design and safety, and fuels/in-core materials/fuel cycle projects. This report is a compilation of work performed on decay heat removal systems for a 2400 MWt GFR during this fiscal year (FY05).

  5. Uncertainties in fission-product decay-heat calculations

    Energy Technology Data Exchange (ETDEWEB)

    Oyamatsu, K.; Ohta, H.; Miyazono, T.; Tasaka, K. [Nagoya Univ. (Japan)

    1997-03-01

    The present precision of the aggregate decay heat calculations is studied quantitatively for 50 fissioning systems. In this evaluation, nuclear data and their uncertainty data are taken from ENDF/B-VI nuclear data library and those which are not available in this library are supplemented by a theoretical consideration. An approximate method is proposed to simplify the evaluation of the uncertainties in the aggregate decay heat calculations so that we can point out easily nuclei which cause large uncertainties in the calculated decay heat values. In this paper, we attempt to clarify the justification of the approximation which was not very clear at the early stage of the study. We find that the aggregate decay heat uncertainties for minor actinides such as Am and Cm isotopes are 3-5 times as large as those for {sup 235}U and {sup 239}Pu. The recommended values by Atomic Energy Society of Japan (AESJ) were given for 3 major fissioning systems, {sup 235}U(t), {sup 239}Pu(t) and {sup 238}U(f). The present results are consistent with the AESJ values for these systems although the two evaluations used different nuclear data libraries and approximations. Therefore, the present results can also be considered to supplement the uncertainty values for the remaining 17 fissioning systems in JNDC2, which were not treated in the AESJ evaluation. Furthermore, we attempt to list nuclear data which cause large uncertainties in decay heat calculations for the future revision of decay and yield data libraries. (author)

  6. {beta}-decay data requirements for reactor decay heat calculations: study of the possible source of the gamma-ray discrepancy in reactor heat summation calculations

    Energy Technology Data Exchange (ETDEWEB)

    Algora, A.; Tain, J.L.; Perez-Cerdan, A.B.; Rubio, B.; Agramunt, J.; Caballero, L.; Nacher, E.; Jordan, D.; Molina, F. [Valencia Univ., IFIC (Spain); Algora, A.; Krasznahorkay, A.; Hunyadi, M.D.; Gulyas, J.; Vitez, A.; Csatlos, M.; Csige, L. [Institute of Nuclear Research, Debrecen (Hungary); Aysto, J.; Penttila, H.; Rinta-Antila, S.; Moore, I.; Eronen, T.; Jokinen, A.; Nieminen, A.; Hakala, J.; Karvonen, P.; Kankainen, A.; Hager, U.; Sonoda, T.; Saastamoinen, A.; Rissanen, J.; Kessler, T.; Weber, C.; Ronkainen, J.; Rahaman, S.; Elomaa, V. [Jyvaskyla Univ. (Finland); Burkard, K.; Huller, W. [GSI, Darmstadt (Germany); Batist, L. [PNPI, Gatchina (Russian Federation); Gelletly, W. [Surrey Univ., Guildford (United Kingdom); Yoshida, T. [Mushashi Institute of Technology (Japan); Nichols, A.L. [IAEA Nuclear Data Section, Vienna (Austria); Sonzogni, A. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY (United States); Perajarvi, K. [STUK, Helsinki (Finland)

    2008-07-01

    The decay heat of fission products plays an important role in predictions of the heat up of nuclear fuel in reactors. The released energy is calculated as the summation of the activities of all fission products P(t) equals {sigma}(E{sub i}*{lambda}{sub i}*N{sub i}(t)), where E{sub i} is the decay energy of nuclide i (gamma and beta component), {lambda}{sub i} is the decay constant of nuclide i and N{sub i}(t) is the number of nuclide i at cooling time t. Even though the reproduction of the measured decay heat has improved in recent years, there is still a long standing discrepancy in the t about 1000 s cooling time for some fuels. A possible explanation to this improper description has been found in the work of Yoshida et al., where it has been shown that the incomplete knowledge of the {beta}-decay of some T{sub c} isotopes can be the source of the systematic discrepancy. We have recently measured the {beta}-decay process of some Tc isotopes using a total absorption spectrometer at the IGISOL facility in Jyvaskyla (Finland). The results of the measurements as well as the their consequences on summation calculations are discussed. (authors)

  7. Optimization design of emergency decay heat removal system for CEFR

    International Nuclear Information System (INIS)

    Background: China experimental fast reactor (CEFR) is the first fast reactor in China, the piping designs are very important for the fast reactor. Purpose: The purpose is to improve the economy of pipeline design for the fast reactor. Methods: According to the optimization principles, redesign the support system of emergency decay heat removal system. Results: The piping of emergency decay heat removal system meets the ASME standard stress limit value under various prospective loads, and reduces the number of dampers, spring hangers. Conclusions: We accumulate layout experience for the support design of high temperature piping by the optimization design for emergency decay heat removal system, lay the foundation for the fast reactor piping design in the future. (authors)

  8. Decay Heat Measurements Using Total Absorption Gamma-ray Spectroscopy

    Science.gov (United States)

    Rice, S.; Valencia, E.; Algora, A.; Taín, J. L.; Regan, P. H.; Podolyák, Z.; Agramunt, J.; Gelletly, W.; Nichols, A. L.

    2012-09-01

    A knowledge of the decay heat emitted by thermal neutron-irradiated nuclear fuel is an important factor in ensuring safe reactor design and operation, spent fuel removal from the core, and subsequent storage prior to and after reprocessing, and waste disposal. Decay heat can be readily calculated from the nuclear decay properties of the fission products, actinides and their decay products as generated within the irradiated fuel. Much of the information comes from experiments performed with HPGe detectors, which often underestimate the beta feeding to states at high excitation energies. This inability to detect high-energy gamma emissions effectively results in the derivation of decay schemes that suffer from the pandemonium effect, although such a serious problem can be avoided through application of total absorption γ-ray spectroscopy (TAS). The beta decay of key radionuclei produced as a consequence of the neutron-induced fission of 235U and 239Pu are being re-assessed by means of this spectroscopic technique. A brief synopsis is given of the Valencia-Surrey (BaF2) TAS detector, and their method of operation, calibration and spectral analysis.

  9. Easy-to-use application programs for decay heat and delayed neutron calculations on personal computers

    Energy Technology Data Exchange (ETDEWEB)

    Oyamatsu, Kazuhiro [Nagoya Univ. (Japan)

    1998-03-01

    Application programs for personal computers are developed to calculate the decay heat power and delayed neutron activity from fission products. The main programs can be used in any computers from personal computers to main frames because their sources are written in Fortran. These programs have user friendly interfaces to be used easily not only for research activities but also for educational purposes. (author)

  10. Decay heat calculations for a 500 kW W-Ta spallation target

    Science.gov (United States)

    Yu, Quanzhi; Lu, Youlian; Hu, Zhiliang; Zhou, Bin; Yin, Wen; Liang, Tianjiao

    2015-05-01

    The China Spallation Neutron Source (CSNS) is a short-pulsed neutron scattering facility. The beam power is designed to be 100 kW in Phase I, with the capability of upgrading to 500 kW. Tantalum (Ta)-cladded tungsten (W) was chosen as the spallation target due to its high neutron yield. Ta claddings can solve the problem of the corrosiveness of W plates, although they produce high decay heat after intense irradiation. This paper presents the decay heat distributions and evolutions for the future upgraded 500 kW W-Ta spallation target. The calculations are performed using the MCNPX2.5 Monte Carlo code and the CINDER'90 activation code. The decay heat distributions show that for the W plates, decay heat is mainly produced via the spallation reaction process, whereas for the Ta claddings, it is mainly produced via the neutron capture process. An effective method of reducing the decay heat in the W-Ta target is also presented and discussed.

  11. Decay heat calculations for a 500 kW W–Ta spallation target

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Quanzhi, E-mail: qzhyu@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Lu, Youlian; Hu, Zhiliang; Zhou, Bin [Dongguan Campus, Institute of High Energy Physics, Chinese Academy of Sciences, Dongguan 523800 (China); Dongguan Neutron Science Center, Dongguan 523800 (China); Yin, Wen; Liang, Tianjiao [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2015-05-15

    The China Spallation Neutron Source (CSNS) is a short-pulsed neutron scattering facility. The beam power is designed to be 100 kW in Phase I, with the capability of upgrading to 500 kW. Tantalum (Ta)-cladded tungsten (W) was chosen as the spallation target due to its high neutron yield. Ta claddings can solve the problem of the corrosiveness of W plates, although they produce high decay heat after intense irradiation. This paper presents the decay heat distributions and evolutions for the future upgraded 500 kW W–Ta spallation target. The calculations are performed using the MCNPX2.5 Monte Carlo code and the CINDER’90 activation code. The decay heat distributions show that for the W plates, decay heat is mainly produced via the spallation reaction process, whereas for the Ta claddings, it is mainly produced via the neutron capture process. An effective method of reducing the decay heat in the W–Ta target is also presented and discussed.

  12. Multidimensional Thermal-Hydraulic Analysis for Decay Heat Exchanger of PGSFR

    International Nuclear Information System (INIS)

    The decay heat exchanger (DHX) of PGSFR is a shell-and-tube type counter-current flow sodium heat exchanger, and each unit is designed for the rated thermal power of 1.0 MWt, which is corresponding to the nominal design capacity of a single passive decay heat removal system (PDHRS) and active decay heat removal system (ADHRS) loops. The DHX unit is fully immersed in the cold sodium pool region and removes the system heat load sufficiently and reliably during the temperature transient. In this work, a multidimensional thermal-hydraulic analysis for the DHX was carried out numerically and the numerical results were compared with the calculated results of the 1-D DHX design code to verify the reliability of the design code. In addition, an influence of the cold pool sodium which flows into the shell-side of the DHX through the shell outlet was evaluated. The SHXSA code was conservative in calculating the pressure drop of the shell-side which is our major concern in designing the natural circulation of the decay heat removal system. It was revealed that the buffer region is needed to reduce the thermal stress in the lower tubesheet by the inflow of the cold pool sodium

  13. Decaying particles do not heat up the universe

    International Nuclear Information System (INIS)

    It is usually assumed that a massive relic species, which comes to dominate the mass density of the Universe and later decays, heats up the Universe when the age of the Universe approx. = its lifetime. We show that if its decay follows the usual exponential decay law, then the Universe is never reheated, rather it tust cools more slowly. We calculate the evolution of the temperature and entropy, and find that to within numerical factors of order unity, the usual estimates for the entropy increase are found to be correct. Our results have implications for primordial nucleosynthesis in scenarios where a massive relic with lifetime approx. = 10-2 to 103 sec is present, and for baryogenesis in the new inflationary Universe scenario

  14. Decay heat removal in GEN IV gas cooled fast reactors

    International Nuclear Information System (INIS)

    The safety goal of the current designs of advanced high-temperature thermal gas-cooled reactors (HTRs) is that no core meltdown would occur in a depressurization event with a combination of concurrent safety system failures. This study focused on the analysis of passive decay heat removal (DHR) in a GEN IV direct-cycle gas-cooled fast reactor (GFR) which is based on the technology developments of the HTRs. Given the different criteria and design characteristics of the GFR, an approach different from that taken for the HTRs for passive DHR would have to be explored. Different design options based on maintaining core flow were evaluated by performing transient analysis of a depressurization accident using the system code RELAP5-3D. The study also reviewed the conceptual design of autonomous systems for shutdown decay heat removal and recommends that future work in this area should be focused on the potential for Brayton cycle DHRs.

  15. Passive Decay Heat Removal System for Micro Modular Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jangsik; Lee, Jeong Ik; Jeong, Yong Hoon [KAIST, Daejeon (Korea, Republic of)

    2015-10-15

    Dry cooling system is applied as waste heat removal system therefore it is able to consider wide construction site. Schematic figure of the reactor is shown in Fig. 1. In safety features, the reactor has double containment and passive decay heat removal (PDHR) system. The double containment prevents leakage from reactor coolant system to be emitted into environment. The passive decay heat removal system copes with design basis accidents (DBAs). Micros Modular Reactor (MMR) which has been being developed in KAIST is S-CO{sub 2} gas cooled reactor and shows many advantages. The S-CO{sub 2} power cycle reduces size of compressor, and it makes small size of power plant enough to be transported by trailer.The passive residual heat removal system is designed and thermal hydraulic (TH) analysis on coolant system is accomplished. In this research, the design process and TH analysis results are presented. PDHR system is designed for MMR and coolant system with the PDHR system is analyzed by MARS-KS code. Conservative assumptions are applied and the results show that PDHR system keeps coolant system under the design limitation.

  16. HTGR spent fuel element decay heat and source term analysis

    International Nuclear Information System (INIS)

    Decay heat, gamma dose rates, and neutron source strengths were determined for spent fuel elements from a High-Temperature Gas-Cooled Reactor (HTGR). The calculations were based on curie values reported in General Atomic Report GA-A13886 for the earlier commercial version of a 3000-MW(t) HTGR utilizing the thorium-uranium four-year fuel cycle. The reactor core was designed for an average thermal power density of 8.5 watts per cm3 and a carbon-to-thorium atom ratio which varies between 210:1 and 240:1. Calculations of decay heat, gamma dose rates, and neutron source strengths were made for spent fuel elements from the initial core and from representative nonrecycle and recycle reloads. The study was performed for decay times from 180 days to 10 years. Tables of the isotopic results are given for both the fertile and fissile particles in the fuel elements. In addition, ordered tables of the important isotopic contributors are presented. Graphical presentations of the results are shown and discussed; in addition, comparisons are made with previous determinations

  17. Castor-1C spent fuel storage cask decay heat, heat transfer, and shielding analyses

    International Nuclear Information System (INIS)

    This report documents the decay heat, heat transfer, and shielding analyses of the Gesellschaft fuer Nuklear Services (GNS) CASTOR-1C cask used in a spent fuel storage demonstration performed at Preussen Elektra's Wurgassen nuclear power plant. The demonstration was performed between March 1982 and January 1984, and resulted in cask and fuel temperature data and cask exterior surface gamma-ray and neutron radiation dose rate measurements. The purpose of the analyses reported here was to evaluate decay heat, heat transfer, and shielding computer codes. The analyses consisted of (1) performing pre-look predictions (predictions performed before the analysts were provided the test data), (2) comparing ORIGEN2 (decay heat), COBRA-SFS and HYDRA (heat transfer), and QAD and DOT (shielding) results to data, and (3) performing post-test analyses if appropriate. Even though two heat transfer codes were used to predict CASTOR-1C cask test data, no attempt was made to compare the two codes. The codes are being evaluated with other test data (single-assembly data and other cask data), and to compare the codes based on one set of data may be premature and lead to erroneous conclusions

  18. Transient Performance of Air-cooled Condensing Heat Exchanger in Long-term Passive Cooling System during Decay Heat Load

    International Nuclear Information System (INIS)

    In the event of a 'loss of coolant accident'(LOCA) and a non-LOCA, the secondary passive cooling system would be activated to cool the steam in a condensing heat exchanger that is immersed in an emergency cooldown tank (ECT). Currently, the capacities of these ECTs are designed to be sufficient to remove the sensible and residual heat from the reactor coolant system for 72 hours after the occurrence of an accident. After the operation of a conventional passive cooling system for an extended period, however, the water level falls as a result of the evaporation from the ECT, as steam is emitted from the open top of the tank. Therefore, the tank should be refilled regularly from an auxiliary water supply system when the system is used for more than 72 hours. Otherwise, the system would fail to dissipate heat from the condensing heat exchanger due to the loss of the cooling water. Ultimately, the functionality of the passive cooling system would be seriously compromised. As a passive means of overcoming the water depletion in the tank, Kim et al. applied for a Korean patent covering the concept of a long-term passive cooling system for an ECT even after 72 hours. This study presents transient performance of ECT with installing air-cooled condensing heat exchanger under decay heat load. The cooling capacity of an air-cooled condensing heat exchanger was evaluated to determine its practicality

  19. Decay heat measurement on fusion reactor materials and validation of calculation code system

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Fujio; Ikeda, Yujiro; Wada, Masayuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Decay heat rates for 32 fusion reactor relevant materials irradiated with 14-MeV neutrons were measured for the cooling time period between 1 minute and 400 days. With using the experimental data base, validity of decay heat calculation systems for fusion reactors were investigated. (author)

  20. Probabilistic approach for decay heat uncertainty estimation using URANIE platform and MENDEL depletion code

    Science.gov (United States)

    Tsilanizara, A.; Gilardi, N.; Huynh, T. D.; Jouanne, C.; Lahaye, S.; Martinez, J. M.; Diop, C. M.

    2014-06-01

    The knowledge of the decay heat quantity and the associated uncertainties are important issues for the safety of nuclear facilities. Many codes are available to estimate the decay heat. ORIGEN, FISPACT, DARWIN/PEPIN2 are part of them. MENDEL is a new depletion code developed at CEA, with new software architecture, devoted to the calculation of physical quantities related to fuel cycle studies, in particular decay heat. The purpose of this paper is to present a probabilistic approach to assess decay heat uncertainty due to the decay data uncertainties from nuclear data evaluation like JEFF-3.1.1 or ENDF/B-VII.1. This probabilistic approach is based both on MENDEL code and URANIE software which is a CEA uncertainty analysis platform. As preliminary applications, single thermal fission of uranium 235, plutonium 239 and PWR UOx spent fuel cell are investigated.

  1. Sodium Experiments on Natural Circulation Decay Heat Removal and 3D Simulation of Plenum Thermal Hydraulics

    International Nuclear Information System (INIS)

    Natural circulation decay heat removal is one of the significant issues for fast reactor safety, especially in long term station blackout events. Several sodium experiments were carried out using a 7-subassembly core model for core thermal hydraulics under natural circulation conditions and for onset transients of natural circulation in a decay heat removal system (DHRS) including natural draft. Significant heat removal via inter-wrapper flow was confirmed in the experiments. Solidification of sodium in an air cooler is one of key issues in loss of heat sink events. Natural circulation characteristics under long-term decay heat removal were also obtained. Multi-dimensional phenomena, e.g., thermal stratification and bypass flow in plenums and/or heat exchangers, may influence the natural circulation. Thus, 3D simulation method was developed for entire region in the primary loop. Comparison of temperature distributions in a DHRS heat exchanger between experiment and analysis was done. (author)

  2. Effect of magnetic field decay on the chemical heating of cooling neutron stars

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xia; KANG Miao; WANG Na

    2013-01-01

    The effect of magnetic field decay on the chemical heating and thermal evolution of neutron stars is discussed in this paper.Our main goal is to study how the chemical heating mechanism and thermal evolution are changed by the field decay and how the magnetic field decay is modified by the thermal evolution.We compare stars cooling with chemical heating with one without chemical heating and find that the decay of the magnetic field is delayed significantly by the chemical heating.We find that the effect of chemical heating has been suppressed through the decaying magnetic field by the spin-down of the stars at a later stage.Compared with typical chemical heating,we find the decay of the magnetic field can even cause the surface temperature to turn down at an older age.When we discuss the cooling of neutron stars,we should consider the coupling effect of the magnetic field and the rotational evolution of neutron stars on the heating mechanisms.

  3. Time decay rates for the equations of the compressible heat-conductive flow through porous media

    Science.gov (United States)

    Chen, Qing; Tan, Zhong; Wu, Guochun

    2015-11-01

    We consider the time decay rates of smooth solutions to the Cauchy problem for the equations of the compressible heat-conductive flow through porous media. We prove the global existence and uniqueness of the solutions by the standard energy method. Moreover, we establish the optimal decay rates of the solution as well as its higher-order spatial derivatives. And the damping effect on the time decay rates of the solution is studied in detail.

  4. Passive Decay Heat Removal Strategy of Integrated Passive Safety System (IPSS) for SBO-combined Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Ho; Chang, Soon Heung; Jeong, Yong Hoon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-10-15

    The weak points of nuclear safety would be in outmoded nuclear power plants like the Fukushima reactors. One of the systems for the safety enhancement is integrated passive safety system (IPSS) proposed after the Fukushima accidents. It has the five functions for the prevention and mitigation of a severe accident. Passive decay heat removal (PDHR) strategy using IPSS is proposed for coping with SBO-combined accidents in this paper. The two systems for removing decay heat before core-melt were applied in the strategy. The accidents were simulated by MARS code. The reference reactor was OPR1000, specifically Ulchin-3 and 4. The accidents included loss-of-coolant accidents (LOCA) because the coolant losses could be occurred in the SBO condition. The examples were the stuck open of PSV, the abnormal open of SDV and the leakage of RCP seal water. Also, as LOCAs with the failure of active safety injection systems were considered, various LOCAs were simulated in SBO. Based on the thermal hydraulic analysis, the probabilistic safety analysis was carried out for the PDHR strategy to estimate the safety enhancement in terms of the variation of core damage frequency. AIMS-PSA developed by KAERI was used for calculating CDF of the plant. The IPSS was applied in the PDHR strategy which was developed in order to cope with the SBO-combined accidents. The estimation for initiating SGGI or PSIS was based on the pressure in RCS. The simulations for accidents showed that the decay heat could be removed for the safety duration time in SBO. The increase of safety duration time from the strategy provides the increase of time for the restoration of AC power.

  5. Improvements on Decay Heat Summation Calculations by Means of Total Absorption Gamma-ray Spectroscopy Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Algora, A.; Sonzogni, A.; Algora, A.; Jordan, D.; Tain, J. L.; Rubio, B.; Agramunt, J.; Caballero, L.; Nacher, E.; Perez-Cerdan, A. B.; Molina, F.; Krasznahorkay, A.; Hunyadi, M. D.; Gulyas, J.; Vitez, A.; Csatlos, M.; Csige, L.; Aysto, J.; Penttila, H.; Rinta-Antila, S.; Moore, I.; Eronen, T.; Jokinen, A.; Nieminen, A.; Hakala, J.; Karvonen, P.; Kankainen, A.; Hager, U.; Sonoda, T.; Saastamoinen, A.; Rissanen, J.; Kessler, T.; Weber, C.; Ronkainen, J.; Rahaman, S.; Elomaa, V.; Burkard, K.; Hueller, W.; Batist, L.; Gelletly, W.; Yoshida, T.; Nichols, A. L.; Sonzogni, A.; Perajarvi, K.

    2011-08-01

    The decay heat of fission products plays an important role in predictions of the heat released by nuclear fuel in reactors. In this contribution we present results of the analysis of the measurement of the beta decay of some refractory isotopes that were considered possible important contributors to the decay heat in reactors. The measurements presented here were performed at the IGISOL facility of the University of Jyvaeskylae, Finland. In our measurements we have combined for the first time a Penning trap (JYFLTRAP), which was used as a high resolution isobaric separator, with a total absorption spectrometer. The results of the measurements as well as their consequences for decay heat summation calculations are discussed.

  6. Fission Product Decay Heat Calculations for Neutron Fission of 232Th

    Science.gov (United States)

    Son, P. N.; Hai, N. X.

    2016-06-01

    Precise information on the decay heat from fission products following times after a fission reaction is necessary for safety designs and operations of nuclear-power reactors, fuel storage, transport flasks, and for spent fuel management and processing. In this study, the timing distributions of fission products' concentrations and their integrated decay heat as function of time following a fast neutron fission reaction of 232Th were exactly calculated by the numerical method with using the DHP code.

  7. [The influence of oil heat treatment on wood decay resistance by Fourier infrared spectrum analysis].

    Science.gov (United States)

    Wang, Ya-Mei; Ma, Shu-Ling; Feng, Li-Qun

    2014-03-01

    Wood preservative treatment can improve defects of plantation wood such as easy to corrupt and moth eaten. Among them heat-treatment is not only environmental and no pollution, also can improve the corrosion resistance and dimension stability of wood. In this test Poplar and Mongolian Seoteh Pine was treated by soybean oil as heat-conducting medium, and the heat treatment wood was studied for indoor decay resistance; wood chemical components before and after treatment, the effect of heat treatment on wood decay resistance performance and main mechanism of action were analysed by Fourier infrared spectrometric. Results showed that the mass loss rate of poplar fell from 19.37% to 5% and Mongolian Seoteh Pine's fell from 8.23% to 3.15%, so oil heat treatment can effectively improve the decay resistance. Infrared spectrum analysis shows that the heat treatment made wood's hydrophilic groups such as hydroxyl groups in largely reduced, absorbing capacity decreased and the moisture of wood rotting fungi necessary was reduced; during the heat treatment wood chemical components such as cellulose, hemicellu lose were degraded, and the nutrient source of wood rotting fungi growth necessary was reduced. Wood decay fungi can grow in the wood to discredit wood is because of that wood can provide better living conditions for wood decay fungi, such as nutrients, water, oxygen, and so on. The cellulose and hemicellulose in wood is the main nutrition source of wood decay fungi. So the oil heat-treatment can reduce the cellulose, hemicellulose nutrition source of wood decay fungi so as to improve the decay resistance of wood.

  8. [The influence of oil heat treatment on wood decay resistance by Fourier infrared spectrum analysis].

    Science.gov (United States)

    Wang, Ya-Mei; Ma, Shu-Ling; Feng, Li-Qun

    2014-03-01

    Wood preservative treatment can improve defects of plantation wood such as easy to corrupt and moth eaten. Among them heat-treatment is not only environmental and no pollution, also can improve the corrosion resistance and dimension stability of wood. In this test Poplar and Mongolian Seoteh Pine was treated by soybean oil as heat-conducting medium, and the heat treatment wood was studied for indoor decay resistance; wood chemical components before and after treatment, the effect of heat treatment on wood decay resistance performance and main mechanism of action were analysed by Fourier infrared spectrometric. Results showed that the mass loss rate of poplar fell from 19.37% to 5% and Mongolian Seoteh Pine's fell from 8.23% to 3.15%, so oil heat treatment can effectively improve the decay resistance. Infrared spectrum analysis shows that the heat treatment made wood's hydrophilic groups such as hydroxyl groups in largely reduced, absorbing capacity decreased and the moisture of wood rotting fungi necessary was reduced; during the heat treatment wood chemical components such as cellulose, hemicellu lose were degraded, and the nutrient source of wood rotting fungi growth necessary was reduced. Wood decay fungi can grow in the wood to discredit wood is because of that wood can provide better living conditions for wood decay fungi, such as nutrients, water, oxygen, and so on. The cellulose and hemicellulose in wood is the main nutrition source of wood decay fungi. So the oil heat-treatment can reduce the cellulose, hemicellulose nutrition source of wood decay fungi so as to improve the decay resistance of wood. PMID:25208386

  9. Development of whole energy absorption spectrometer for decay heat measurement on fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Fujio; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    To measure decay heat on fusion reactor materials irradiated by D-T neutrons, a Whole Energy Absorption Spectrometer (WEAS) consisting of a pair of large BGO (bismuth-germanate) scintillators was developed. Feasibility of decay heat measurement with WEAS for various materials and for a wide range of half-lives (seconds - years) was demonstrated by experiments at FNS. Features of WEAS, such as high sensitivity, radioactivity identification, and reasonably low experimental uncertainty of {approx} 10 %, were found. (author)

  10. Beta and gamma decay-heat measurements for fast and thermal reactors, particularly for Pu-239

    Energy Technology Data Exchange (ETDEWEB)

    Dickens, J.K.

    1981-01-01

    The mounting evidence suggests (a) that the ORNL thermal-neutron fission decay heat data are likely correct to within stated uncertainties; (b) present data files (ENDF/B-V and others related to it) require more effort, and as improvements are made agreement with ORNL results is likely to become better; and (c) fast fission decay heat, induced by reactor-spectrum neutrons, appears to be little, if any, different from thermal-neutron fission-decay heat. The ANS 5.1 working group seems to be moving toward the above position but the standard for /sup 235/U has not yet been revised. Using /sup 235/U decay-heat data for /sup 239/Pu is quite conservative. Use of /sup 235/U decay-heat data for /sup 241/Pu decay-heat data as required in the standard is conservative only because of the over-statement (by approx. = 8%) of the /sup 235/U data in the standard.

  11. Decay heat removal in pool type fast reactor using passive systems

    Energy Technology Data Exchange (ETDEWEB)

    Parthasarathy, U. [Thermal Hydraulics Section, Nuclear and Safety Engineering Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Sundararajan, T. [Department of Mechanical Engineering, IIT-Madras, Chennai 600 036 (India); Balaji, C., E-mail: balaji@iitm.ac.in [Department of Mechanical Engineering, IIT-Madras, Chennai 600 036 (India); Velusamy, K.; Chellapandi, P.; Chetal, S.C. [Thermal Hydraulics Section, Nuclear and Safety Engineering Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Three dimensional thermal hydraulic analysis of decay heat system in a fast reactor model predictions compared with experimental results from PHENIX. Black-Right-Pointing-Pointer Calculations confirm adequacy of natural convection in decay heat removal. Black-Right-Pointing-Pointer Inter-wrapper flow found to reduce peak temperatures by 50 K in the blanket zone. - Abstract: Post shutdown decay heat removal in a fast reactor is one of the most important safety functions which must be accomplished with a very high reliability. To achieve high reliability, the fast breeder reactor design has emphasized on passive or near passive decay heat removal systems utilizing the natural convection in the heat removal path. A typical passive decay heat removal system used in recent designs of fast breeder reactors consists of a sodium to sodium heat exchanger and sodium to air heat exchanger which together remove heat directly from the hot pool to the final heat sink, which is air. Since these are safety systems, it is necessary to confirm the design with detailed numerical analysis. The numerical studies include pool hydraulics, natural convection phenomena in closed loops, flow through narrow gaps between SA, multi-scale modeling, etc. Toward understanding the evolution of thermal hydraulic parameters during natural convection decay heat removal, a three-dimensional CFD model for the primary system coupled with an appropriate one-dimensional model for the secondary system is proposed. The model has been validated against the results of natural convection test conducted in PHENIX reactor. Adopting the model for the Indian PFBR, six different decay heat removal cases have been studied which bring out the effect of safety grade decay heat removal system (SGDHRS) capacity, secondary sodium inventory and inter-wrapper flow heat transfer on the subassembly outlet temperatures that are important for safety evaluation of the reactor. From the

  12. Decay heat removal in pool type fast reactor using passive systems

    International Nuclear Information System (INIS)

    Highlights: ► Three dimensional thermal hydraulic analysis of decay heat system in a fast reactor model predictions compared with experimental results from PHENIX. ► Calculations confirm adequacy of natural convection in decay heat removal. ► Inter-wrapper flow found to reduce peak temperatures by 50 K in the blanket zone. - Abstract: Post shutdown decay heat removal in a fast reactor is one of the most important safety functions which must be accomplished with a very high reliability. To achieve high reliability, the fast breeder reactor design has emphasized on passive or near passive decay heat removal systems utilizing the natural convection in the heat removal path. A typical passive decay heat removal system used in recent designs of fast breeder reactors consists of a sodium to sodium heat exchanger and sodium to air heat exchanger which together remove heat directly from the hot pool to the final heat sink, which is air. Since these are safety systems, it is necessary to confirm the design with detailed numerical analysis. The numerical studies include pool hydraulics, natural convection phenomena in closed loops, flow through narrow gaps between SA, multi-scale modeling, etc. Toward understanding the evolution of thermal hydraulic parameters during natural convection decay heat removal, a three-dimensional CFD model for the primary system coupled with an appropriate one-dimensional model for the secondary system is proposed. The model has been validated against the results of natural convection test conducted in PHENIX reactor. Adopting the model for the Indian PFBR, six different decay heat removal cases have been studied which bring out the effect of safety grade decay heat removal system (SGDHRS) capacity, secondary sodium inventory and inter-wrapper flow heat transfer on the subassembly outlet temperatures that are important for safety evaluation of the reactor. From the results, it is concluded that the delay in initiation of SGDHRS, replacement

  13. Decay heat and anti-neutrino energy spectra in fission fragments from total absorption spectroscopy

    Science.gov (United States)

    Rykaczewski, Krzysztof

    2015-10-01

    Decay studies of over forty 238U fission products have been studied using ORNL's Modular Total Absorption Spectrometer. The results are showing increased decay heat values, by 10% to 50%, and the energy spectra of anti-neutrinos shifted towards lower energies. The latter effect is resulting in a reduced number of anti-neutrinos interacting with matter, often by tens of percent per fission product. The results for several studied nuclei will be presented and their impact on decay heat pattern in power reactors and reactor anti-neutrino physics will be discussed.

  14. Decay heat removal and heat transfer under normal and accident conditions in gas cooled reactors

    International Nuclear Information System (INIS)

    The meeting was convened by the International Atomic Energy Agency on the recommendation of the IAEA's International Working Group on Gas Cooled Reactors. It was attended by participants from China, France, Germany, Japan, Poland, the Russian Federation, Switzerland, the United Kingdom and the United States of America. The meeting was chaired by Prof. Dr. K. Kugeler and Prof. Dr. E. Hicken, Directors of the Institute for Safety Research Technology of the KFA Research Center, and covered the following: Design and licensing requirements for gas cooled reactors; concepts for decay heat removal in modern gas cooled reactors; analytical methods for predictions of thermal response, accuracy of predictions; experimental data for validation of predictive methods - operational experience from gas cooled reactors and experimental data from test facilities. Refs, figs and tabs

  15. Total Absorption Spectroscopy of Fission Fragments Relevant for Reactor Antineutrino Spectra and Decay Heat Calculations

    Science.gov (United States)

    Porta, A.; Zakari-Issoufou, A.-A.; Fallot, M.; Algora, A.; Tain, J. L.; Valencia, E.; Rice, S.; Bui, V. M.; Cormon, S.; Estienne, M.; Agramunt, J.; Äystö, J.; Bowry, M.; Briz, J. A.; Caballero-Folch, R.; Cano-Ott, D.; Cucouanes, A.; Elomaa, V.-V.; Eronen, T.; Estévez, E.; Farrelly, G. F.; Garcia, A. R.; Gelletly, W.; Gomez-Hornillos, M. B.; Gorlychev, V.; Hakala, J.; Jokinen, A.; Jordan, M. D.; Kankainen, A.; Karvonen, P.; Kolhinen, V. S.; Kondev, F. G.; Martinez, T.; Mendoza, E.; Molina, F.; Moore, I.; Perez-Cerdán, A. B.; Podolyák, Zs.; Penttilä, H.; Regan, P. H.; Reponen, M.; Rissanen, J.; Rubio, B.; Shiba, T.; Sonzogni, A. A.; Weber, C.

    2016-03-01

    Beta decay of fission products is at the origin of decay heat and antineutrino emission in nuclear reactors. Decay heat represents about 7% of the reactor power during operation and strongly impacts reactor safety. Reactor antineutrino detection is used in several fundamental neutrino physics experiments and it can also be used for reactor monitoring and non-proliferation purposes. 92,93Rb are two fission products of importance in reactor antineutrino spectra and decay heat, but their β-decay properties are not well known. New measurements of 92,93Rb β-decay properties have been performed at the IGISOL facility (Jyväskylä, Finland) using Total Absorption Spectroscopy (TAS). TAS is complementary to techniques based on Germanium detectors. It implies the use of a calorimeter to measure the total gamma intensity de-exciting each level in the daughter nucleus providing a direct measurement of the beta feeding. In these proceedings we present preliminary results for 93Rb, our measured beta feedings for 92Rb and we show the impact of these results on reactor antineutrino spectra and decay heat calculations.

  16. Total Absorption Spectroscopy of Fission Fragments Relevant for Reactor Antineutrino Spectra and Decay Heat Calculations

    Directory of Open Access Journals (Sweden)

    Porta A.

    2016-01-01

    Full Text Available Beta decay of fission products is at the origin of decay heat and antineutrino emission in nuclear reactors. Decay heat represents about 7% of the reactor power during operation and strongly impacts reactor safety. Reactor antineutrino detection is used in several fundamental neutrino physics experiments and it can also be used for reactor monitoring and non-proliferation purposes. 92,93Rb are two fission products of importance in reactor antineutrino spectra and decay heat, but their β-decay properties are not well known. New measurements of 92,93Rb β-decay properties have been performed at the IGISOL facility (Jyväskylä, Finland using Total Absorption Spectroscopy (TAS. TAS is complementary to techniques based on Germanium detectors. It implies the use of a calorimeter to measure the total gamma intensity de-exciting each level in the daughter nucleus providing a direct measurement of the beta feeding. In these proceedings we present preliminary results for 93Rb, our measured beta feedings for 92Rb and we show the impact of these results on reactor antineutrino spectra and decay heat calculations.

  17. Measurement and analysis of decay heat of fast reactor spent fuel

    International Nuclear Information System (INIS)

    Decay heat of the JOYO Mk-II spent fuel subassemblies was measured using the calorimetric method as a non-destructive examination. The measurement of the subassembly was taken in the spent fuel storage pond at JOYO. Its burn-up was approximately 60 GWd/t and the cooling time was between 24 and 258 days. The measured decay heat was compared with the calculated values by 'ORIGEN2' code using the cross section library of JENDL-3.2, and the decay data and the fission yield data library of JNDC-V2. Calculated to Experimental (C/E) values for the measured subassembly were 0.96 - 0.90. The decay heat generated by 238Pu and 241Am, which amount to 1% of initial composition of the fresh fuel, reached 6% - 17% of decay heat during 24 -258 days of cooling time. These results indicate that the initial composition and the burn-up calculation of actinides are important to accurately evaluate the decay heat of spent fuel. (author)

  18. A passive decay heat removal system for LWRs based on air cooling

    Energy Technology Data Exchange (ETDEWEB)

    Mochizuki, Hiroyasu, E-mail: mochizki@u-fukui.ac.jp [Research Institute of Nuclear Engineering, University of Fukui, 1-2-4 Kanawa-cho, Tsuruga, Fukui 914-0055 (Japan); Yano, Takahiro [Graduate School of Engineering, University of Fukui, 1-2-4 Kanawa-cho, Tsuruga, Fukui 914-0055 (Japan)

    2015-05-15

    Highlights: • A passive decay heat removal system for LWRs is discussed. • An air cooler model which condenses steam is developed. • The decay heat can be removed by air coolers with forced convection. • The dimensions of the air cooler are proposed. - Abstract: The present paper describes the capability of an air cooling system (ACS) to remove decay heat from a core of LWR such as an advanced boiling water reactor (ABWR) and a pressurized water reactor (PWR). The motivation of the present research is the Fukushima severe accident (SA) on 11 March 2011. Since emergency cooling systems using electricity were not available due to station blackout (SBO) and malfunctions, many engineers might understand that water cooling was not completely reliable. Therefore, a passive decay heat removal (DHR) system would be proposed in order to prevent such an SA under the conditions of an SBO event. The plant behaviors during the SBO are calculated using the system code NETFLOW++ for the ABWR and PWR with the ACS. Two types of air coolers (ACs) are applied for the ABWR, i.e., a steam condensing air cooler (SCAC) of which intake for heat transfer tubes is provided in the steam region, and single-phase type of which intake is provided in the water region. The DHR characteristics are calculated under the conditions of the forced air circulation and also the natural air convection. As a result of the calculations, the decay heat can be removed safely by the reasonably sized ACS when heat transfer tubes are cooled with the forced air circulation. The heat removal rate per one finned heat transfer tube is evaluated as a function of air flow rate. The heat removal rate increases as a function of the air flow rate.

  19. Los Alamos PWR decay-heat-removal studies. Summary results and conclusions

    International Nuclear Information System (INIS)

    The adequacy of shutdown-decay-heat removal in pressurized water reactors (PWRs) is currently under investigation by the Nuclear Regulatory Commission. One part of this effort is the review of feed-and-bleed procedures that could be used if the normal cooling mode through the steam generators were unavailable. Feed-and-bleed cooling is effected by manually activating the high-pressure injection (HPI) system and opening the power-operated relief valves (PORVs) to release the core decay energy. The feasibility of the feed-and-bleed concept as a diverse mode of heat removal has been evaluated at the Los Alamos National Laboratory. The TRAC-PF1 code has been used to predict the expected performance of the Oconee-1 and Calvert Cliffs-1 reactors of Bobcock and Wilcox and Combustion Engineering, respectively, and the Zion-1 and H.B. Robinson-2 plants of Westinghouse. Feed and bleed was successfully applied in each of the four plants studied, provided it was initiated no later than the time of loss of secondary heat sink. Feed and bleed was successfully applied in two of the plants, Oconee-1 and Zion-1, provided it was initiated no later than the time of primary system saturation. Feed and bleed in Calvert Cliffs-1 when initiated at the time of primary system saturation did result in core dryout; however, the core heatup was eventually terminated by coolant injection. Feed-and-bleed initiation at primary system saturation was not studied for H.B. Robinson-2. Insights developed during the analyses of specific plant transients have been identified and documented. 33 refs., 107 figs., 26 tabs

  20. Radiotoxicity and decay heat power of spent nuclear fuel of VVER type reactors at long-term storage.

    Science.gov (United States)

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Radiotoxicity and decay heat power of the spent nuclear fuel of VVER-1000 type reactors are calculated during storage time up to 300,000 y. Decay heat power of radioactive waste (radwaste) determines parameters of the heat removal system for the safe storage of spent nuclear fuel. Radiotoxicity determines the radiological hazard of radwaste after its leakage and penetration into the environment.

  1. The decay heat of fission products and actinides of the SNR-300

    International Nuclear Information System (INIS)

    The report describes the computer code RASPA, which calculates the build-up and decay of fission products and actinides. The verification of the code and its library has been performed by comparison with theoretical and experimental results of other authors, whereby a good agreement has been achieved. Furthermore, an error analysis has shown, that the error of the calculated decay heat, which is induced by uncertainties of nuclear data, is less than 10 % up to decay times of one month. The results of calculations of the time dependent decay heat and the gamma source strength in various zones of the cores Mark-Ia and Mark-II of the SNR-300 are documented and discussed in detail

  2. Study on thermal-hydraulics of natural circulation operation for decay heat removal of LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Tomonari [Central Research Inst. of Electric Power Industry, Abiko, Chiba (Japan). Abiko Research Lab

    2000-05-01

    Thermal-hydraulic characteristics of the decay heat removal system (DHRS) has been evaluated by both a water test and its computational analysis. The direct reactor auxiliary cooling system (DRACS) was studied as a representative DHRS in the LMFBR design. A natural circulation flow of the DRACS is originated from the buoyancy force balanced with the pressure loss within the active core. Hence it appears that the performance of the DRACS could be fully estimated by the thermal-hydraulic study of one fuel sub-assembly under the condition of low flow rate. The inter-wrapper flow occurring in the gap between core sub-assemblies under the natural circulation operation might have a large capacity to cool the core. An inverse flow occurring at the outer region of the core was due to the cooling effect of the inter-wrapper flow. (author)

  3. Thermal-hydraulic characteristics of natural circulation operation for decay heat removal of LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Tomonari [Central Research Inst. of Electric Power Industry, Abiko, Chiba (Japan); Watanabe, Osamu [Advanced Reactor Technology Co., Ltd., Tokyo (Japan)

    2000-10-01

    Thermal-hydraulic characteristics of the decay heat removal system (DHRS) has been evaluated by both a water test and its computational analysis. The direct reactor auxiliary cooling system (DRACS) was studied as a representative DHRS in the LMFBR design. A natural circulation flow of the DRACS is originated from the buoyancy force balanced with the pressure loss within the active core. Hence it appears that the performance of the DRACS could be fully estimated by the thermal-hydraulic study of one fuel sub-assembly under the condition of low flow rate. The inter-wrapper flow occurring in the gap between core sub-assemblies under the natural circulation operation might have a large capacity to cool the core. An inverse flow occurring at the outer region of the core was due to the cooling effect of the inter-wrapper flow. (author)

  4. Revisions to the decay heat standard: ANSI/ANS 5.1

    Energy Technology Data Exchange (ETDEWEB)

    Brady Raap, M. C. [Pacific Northwest National Laboratory, 902 Battelle Blvd., Richland, WA 99352 (United States); Gauld, I. C. [Oak Ridge National Laboratory, Oak Ridge, TN 37832 (United States); Dickens, J. K. [Dept. of Physics, Univ. of Tennessee, Knoxville, TN 37996 (United States); Wilson, W. B. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2006-07-01

    This paper presents a summary of the 2005 revision to ANSI/ANS-5.1, Decay Heat Power for Light Water Reactors. The 2005 revision to ANSI/ANS-5.1 [1] represented an important milestone for this Standard. The reconstitution of the working group, incorporation of ENDF/B-VI data, and revisions to the 'simplified method' are the most significant accomplishments realized in the approval and publication of this Standard. A discussion comparing the content of the 2005 revision to the previous version of the Standard [2] is provided. In addition, an outline of the current activities of the working group and goals for the next revision is presented. (authors)

  5. Preliminary Test of a small heat pipe for hybrid control rod in-core passive decay heat removal system

    International Nuclear Information System (INIS)

    This paper introduces 'Hybrid control rod' combining its original function and heat removal ability. The high temperature operation and high resistance of radiation should be considered to adopt the hybrid heat pipe at the in-core condition. Other design consideration is to make extra inlet parts because it has a high risk of inlet boundary failure. It means that the introduction of heat pipe system is difficult to present nuclear power plants. The other concepts are presented to out-core cooling design but it has low performance compared with in-core heat removal system. Hybrid heat pipe for in-core heat removal system suggests the solution of these problems. Ultimate objective of this research is to develop the passive emergency decay heat removal system using hybrid heat pipes targeting design bases accidents such as station black-out (SBO) and small break loss of coolant accident (SBLOCA). The purpose of this work is to confirm the performance and heat transfer behavior of hybrid heat pipe. The hybrid heat pipe has special condition for operation. Therefore, it is hard to analyze their behavior in core. Table I shows the characteristics of hybrid heat pipe and consideration for manufacturing the heat pipe

  6. Preliminary Test of a small heat pipe for hybrid control rod in-core passive decay heat removal system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Guk; Ban, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-05-15

    This paper introduces 'Hybrid control rod' combining its original function and heat removal ability. The high temperature operation and high resistance of radiation should be considered to adopt the hybrid heat pipe at the in-core condition. Other design consideration is to make extra inlet parts because it has a high risk of inlet boundary failure. It means that the introduction of heat pipe system is difficult to present nuclear power plants. The other concepts are presented to out-core cooling design but it has low performance compared with in-core heat removal system. Hybrid heat pipe for in-core heat removal system suggests the solution of these problems. Ultimate objective of this research is to develop the passive emergency decay heat removal system using hybrid heat pipes targeting design bases accidents such as station black-out (SBO) and small break loss of coolant accident (SBLOCA). The purpose of this work is to confirm the performance and heat transfer behavior of hybrid heat pipe. The hybrid heat pipe has special condition for operation. Therefore, it is hard to analyze their behavior in core. Table I shows the characteristics of hybrid heat pipe and consideration for manufacturing the heat pipe.

  7. Water test of natural circulation for decay heat removal in JSFR

    International Nuclear Information System (INIS)

    Japan Atomic Energy Agency (JAEA) is conducting a design study of Japan Sodium-cooled Fast Reactor (JSFR), in which a decay heat removal system (DHRS) utilizing natural circulation (NC) is applied as an innovative technology. The Central Research Institute of Electric Power Industry (CRIEPI) has carried out a water test to verify the applicability of NC to decay heat removal. The test used a 1/10-scale model of JSFR. Key issues on thermal-hydraulics were identified through simulation tests on representative events. Measures were also proposed to resolve these issues. The present study has demonstrated that a sufficient and stable NC is established in each event. (author)

  8. Water test of natural circulation for decay heat removal in JSFR

    Energy Technology Data Exchange (ETDEWEB)

    Koga, T.; Murakami, T.; Eguchi, Y., E-mail: koga@criepi.denken.or.jp, E-mail: murakami@criepi.denken.or.jp, E-mail: eguchi@criepi.denken.or.jp [Central Research Inst. of Electric Power Industry (CRIEPI), Abiko-shi, Chiba-ken (Japan); Matsuzawa, T.; Watanabe, O., E-mail: takaharu_matsuzawa@mfbr.mhi.co.jp, E-mail: osamu4_watanabe@mfbr.mhi.co.jp [Mitsubishi FBR Systems, Inc. (MFBR), Shibuya-ku, Tokyo (Japan)

    2011-07-01

    Japan Atomic Energy Agency (JAEA) is conducting a design study of Japan Sodium-cooled Fast Reactor (JSFR), in which a decay heat removal system (DHRS) utilizing natural circulation (NC) is applied as an innovative technology. The Central Research Institute of Electric Power Industry (CRIEPI) has carried out a water test to verify the applicability of NC to decay heat removal. The test used a 1/10-scale model of JSFR. Key issues on thermal-hydraulics were identified through simulation tests on representative events. Measures were also proposed to resolve these issues. The present study has demonstrated that a sufficient and stable NC is established in each event. (author)

  9. Conceptual study of ferromagnetic pebbles for heat exhaust in fusion reactors with short power decay length

    OpenAIRE

    Gierse, N.; Coenen, J W; C. Thomser; Panin, A.; Ch. Linsmeier; Unterberg, B.; Philipps, V

    2015-01-01

    Ferromagnetic pebbles are investigated as high heat flux (q∥) plasma facing components in fusion devices with short power decay length (λq) on a conceptual level. The ability of a pebble concept to cope with high heat fluxes is retained and extended by the acceleration of ferromagnetic pebbles in magnetic fields. An alloying concept suited for fusion application is outlined and the compatibility of ferromagnetic pebbles with plasma operation is discussed. Steel grade 1.4510 is chosen as a ...

  10. VVER-1000/V320 decay heat analysis involving TVS-M and TVSA fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Petkov, Plamen V. [' Kozloduy' NPP, 3321 Kozloduy, Vratsa (Bulgaria)], E-mail: pvpetkov@yahoo.com; Hristov, Danail V. [' Kozloduy' NPP, 3321 Kozloduy, Vratsa (Bulgaria)], E-mail: dvhristov@npp.bg

    2008-12-15

    MELCOR 1.8.4 is an integral computer code, developed for severe accident calculations. It is used primarily for the simulation of PWR and BWR types of reactors as there exists an internal database, suitable for modeling of their core inventory. Despite similarity between VVER-1000/V320 and PWR, accounting of specificities of Russian reactor designs is still required. Part of it is the simulation of core decay heat rate after the shutdown. MELCOR 1.8.4 distinguishes fifteen classes. Each of them contains chemical elements with similar properties. Twelve are involved in radioactive products decay. In current paper the authors present two boundary reactor core loadings, designed with corresponding fuel assemblies: TVS-M and TVSA. They have calculated decay heat after reactor shutdown from 100% and 104% of nominal power by SCALE 4.4a package. The amount of generated nuclides had also been estimated. Irradiation history had been accounted as proposed in Kolobashkin et al. (p. 141) [Kolobashkin, V.M., Rubtsov, P.M., Rujanskiy, P.A., Sidorenko, V.D., 1983. Radionuclide Inventory Estimation Handbook (on Russian). Energoatomizdat, Moscow, pp. 138-188]. Newly developed Core Inventory Estimation Tool (CIET), described in this paper, written and tested previously, has been used for the evaluation of core decay heat fractions, distributed over chemical classes. Twelve curves were generated by following the same numerical procedure implemented in MELCOR for representation of decay in W/kg. Comparison of chemical element decay rates to the defaults for PWR shows deviations from the expectations to maximal values of 37% in Uranium for TVSA fuel assemblies. The total number of radionuclides, separated in chemical classes, given in Gauntt et al. [Gauntt, R.O., Cole, R.K., Rodrigez, S.B., Sanders, R.L., Smith, R.C., Stuard, D.S., Summers, R.M., Young, M.F., 1997. MELCOR Computer Code Manuals. NUREG/CR-6119 Report, Vol. 1 and Vol. 2, SAND97-2398] was compared to the ones involved in

  11. DECAY RESISTANCE AND PHYSICAL PROPERTIES OF OIL HEAT TREATED ASPEN WOOD

    Directory of Open Access Journals (Sweden)

    Behzad Bazyar

    2011-12-01

    Full Text Available The decay resistance of oil-heat treated aspen wood (Populus tremula l. against white rot fungi (Coriolus versicolor and brown rot fungi (Coniophora puteana was investigated. Three different temperature stages and two time levels for oil heat treatment for the selection of optimum conditions were determined. Linseed oil as a heating medium was used. The mass loss of treated samples that were exposed to both fungi was significantly lower than that of the control samples. Results also showed improvement in dimensional stability after oil heat treatment. Decay resistance and dimensional stability of aspen wood were increased significantly with temperature increasing, but time seemed to have no effect on those properties. Oil heat treatment is a suitable method to improve decay resistance of aspen wood as it reduced the mass loss by 71% and 77% against Coriolus versicolor and Coniophora puteana compared with control samples, respectively. On the other hand, oil heat treatment improved the dimensional stability by about 20.5%.

  12. Integral decay-heat measurements and comparisons to ENDF/B--IV and V

    Energy Technology Data Exchange (ETDEWEB)

    England, T.R.; Schenter, R.E.; Schmittroth, F.

    1978-05-22

    Results from recent integral decay-power experiments are presented and compared with summation calculations. The experiments include the decay power following thermal fission of /sup 233/U, /sup 235/U, and /sup 239/Pu. The summation calculations use ENDF/B-IV decay data and yields from Versions IV and V. Limited comparisons of experimental ..beta.. and ..gamma.. spectra with summation calculations using ENDF/B-IV are included. Generalized least-squares methods are applied to the recent /sup 235/U and /sup 239/Pu decay-power experiments and summation calculations to arrive at evaluated values and uncertainties. Results for /sup 235/U imply uncertainties less than 2% (1 sigma) for the ''infinite'' exposure case for all cooling times greater than 10 seconds. The uncertainties for /sup 239/Pu are larger. Accurate analytical representations of the decay power are presented for /sup 235/,/sup 238/U, and /sup 239/Pu for use in light-water reactors and as the nominal values in the new ANS 5.1 Draft Standard (1978). Comparisons of the nominal values with ENDF/B-IV and the 1973 ANS Draft Standard in current use are included. Gas content, important to decay-heat experiments, and absorption effects on decay power are reviewed. 37 figures, 8 tables.

  13. Integral decay-heat measurements and comparisons to ENDF/B-IV and V

    Energy Technology Data Exchange (ETDEWEB)

    England, T.R.; Schenter, R.E.; Schmittroth, F.

    1978-07-01

    Results from recent integral decay-power experiments are presented and compared with summation calculations. The experiments include the decay power following thermal fission of /sup 233/U, /sup 235/U, and /sup 239/Pu. The summation calculations use ENDF/B-IV decay data and yields from Versions IV and V. Limited comparisons of experimental ..beta.. and ..gamma.. spectra with summation calculations using ENDF/B-IV are included. Generalized least-squares methods are applied to the recent /sup 235/U and /sup 239/Pu decay-power experiments and summation calculations to arrive at evaluated values and uncertainties. Results for /sup 235/U imply uncertainties less than 2% (1 sigma) for the ''infinite'' exposure case for all cooling times greater than 10 seconds. The uncertainties for /sup 239/Pu are larger. Accurate analytical representations of the decay power are presented for /sup 235/ /sup 238/U, and /sup 239/Pu for use in light-water reactors and as the nominal values in the new ANS 5.1 Draft Standard (1978). Comparisons of the nominal values with ENDF/B-IV and the 1973 ANS Draft Standard in current use are included. Gas content, important to decay-heat experiments, and absorption effects on decay power are reviewed. 37 figures, 8 tables.

  14. Application of optimal estimation techniques to FFTF decay heat removal analysis

    International Nuclear Information System (INIS)

    The verification and adjustment of plant models for decay heat removal analysis using a mix of engineering judgment and formal techniques from control theory are discussed. The formal techniques facilitate dealing with typical test data which are noisy, redundant and do not measure all of the plant model state variables directly. Two pretest examples are presented. 5 refs

  15. Thermal Capacitance (Slug) Calorimeter Theory Including Heat Losses and Other Decaying Processes

    Science.gov (United States)

    Hightower, T. Mark; Olivares, Ricardo A.; Philippidis, Daniel

    2008-01-01

    A mathematical model, termed the Slug Loss Model, has been developed for describing thermal capacitance (slug) calorimeter behavior when heat losses and other decaying processes are not negligible. This model results in the temperature time slope taking the mathematical form of exponential decay. When data is found to fit well to this model, it allows a heat flux value to be calculated that corrects for the losses and may be a better estimate of the cold wall fully catalytic heat flux, as is desired in arc jet testing. The model was applied to the data from a copper slug calorimeter inserted during a particularly severe high heating rate arc jet run to illustrate its use. The Slug Loss Model gave a cold wall heat flux 15% higher than the value of 2,250 W/sq cm obtained from the conventional approach to processing the data (where no correction is made for losses). For comparison, a Finite Element Analysis (FEA) model was created and applied to the same data, where conduction heat losses from the slug were simulated. The heat flux determined by the FEA model was found to be in close agreement with the heat flux determined by the Slug Loss Model.

  16. FIP Bias Evolution in a Decaying Active Region

    CERN Document Server

    Baker, D; Démoulin, P; Yardley, S L; van Driel-Gesztelyi, L; Long, D M; Green, L M

    2015-01-01

    Solar coronal plasma composition is typically characterized by first ionization potential (FIP) bias. Using spectra obtained by Hinode's EUV Imaging Spectrometer (EIS) instrument, we present a series of large-scale, spatially resolved composition maps of active region (AR) 11389. The composition maps show how FIP bias evolves within the decaying AR from 2012 January 4-6. Globally, FIP bias decreases throughout the AR. We analyzed areas of significant plasma composition changes within the decaying AR and found that small-scale evolution in the photospheric magnetic field is closely linked to the FIP bias evolution observed in the corona. During the AR's decay phase, small bipoles emerging within supergranular cells reconnect with the pre-existing AR field, creating a pathway along which photospheric and coronal plasmas can mix. The mixing time scales are shorter than those of plasma enrichment processes. Eruptive activity also results in shifting the FIP bias closer to photospheric in the affected areas. Final...

  17. On Error Analysis of ORIGEN Decay Data Library Based on ENDF/B-VII.1 via Decay Heat Estimation after a Fission Event

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Heon; Gil, Choong-Sup; Lee, Young-Ouk [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The method is strongly dependent on the available nuclear structure data, i.e., fission product yield data and decay data. Consequently, the improvements in the nuclear structure data could have guaranteed more reliable decay heat estimation for short cooling times after fission. The SCALE-6.1.3 code package includes the ENDF/B-VII.0-based fission product yield data and ENDF/B-VII.1-based decay data libraries for the ORIGEN-S code. The generation and validation of the new ORIGEN-S yield data libraries based on the recently available fission product yield data such as ENDF/B-VII.1, JEFF-3.1.1, JENDL/FPY-2011, and JENDL-4.0 have been presented in the previous study. According to the study, the yield data library in the SCALE-6.1.3 could be regarded as the latest one because it resulted in almost the same outcomes as the ENDF/B-VII.1. A research project on the production of the nuclear structure data for decay heat estimation of nuclear fuel has been carried out in Korea Atomic Energy Research Institute (KAERI). The data errors contained in the ORIGEN-S decay data library of SCALE-6.1.3 have been clearly identified by their changing variables. Also, the impacts of the decay data errors have been analyzed by estimating the decay heats for the fission product nuclides and their daughters after {sup 235}U thermal-neutron fission. Although the impacts of decay data errors are quite small, it reminds us the possible importance of decay data when estimating the decay heat for short cooling times after a fission event.

  18. Study on a decay heat removal system of light water reactors using air coolers

    International Nuclear Information System (INIS)

    In the present work, a passive decay heat removal system for light water reactors (LWRs) based on a new concept is studied referring to an air cooling system (ACS) of the fast breeder reactor Monju. The present study will contribute to the reduction of severe accident risks of nuclear power plants. In this system, a blower for an air cooler (AC) is operated using the rotation of a small steam turbine by generated steam in order to cool heat transfer tubes by forced convection of air. The purpose of the present work is to investigate the plant transient caused by a station blackout (SBO) using the plant system code NETFLOW++ and decay heat removal characteristics. A calculation model is the Advanced Boiling Water Reactor (ABWR) in Japan. (author)

  19. Approximation of the decay of fission and activation product mixtures

    International Nuclear Information System (INIS)

    The decay of the exposure rate from a mixture of fission and activation products is a complex function of time. The exact solution of the problem involves the solution of more than 150 tenth order Bateman equations. An approximation of this function is required for the practical solution of problems involving multiple integrations of this function. Historically this has been a power function, or a series of power functions, of time. The approach selected here has been to approximate the decay with a sum of exponential functions. This produces a continuous, single valued function, that can be made to approximate the given decay scheme to any desired degree of closeness. Further, the integral of the sum is easily calculated over any period. 3 refs

  20. Decay Heat Removal and Transient Analysis in Accidental Conditions in the EFIT Reactor

    Directory of Open Access Journals (Sweden)

    Giacomino Bandini

    2008-01-01

    Full Text Available The development of a conceptual design of an industrial-scale transmutation facility (EFIT of several 100 MW thermal power based on accelerator-driven system (ADS is addressed in the frame of the European EUROTRANS Integral Project. In normal operation, the core power of EFIT reactor is removed through steam generators by four secondary loops fed by water. A safety-related decay heat removal (DHR system provided with four independent inherently safe loops is installed in the primary vessel to remove the decay heat by natural convection circulation under accidental conditions which are caused by a loss-of-heat sink (LOHS. In order to confirm the adequacy of the adopted solution for decay heat removal in accidental conditions, some multi-D analyses have been carried out with the SIMMER-III code. The results of the SIMMER-III code have been then used to support the RELAP5 1D representation of the natural circulation flow paths in the reactor vessel. Finally, the thermal-hydraulic RELAP5 code has been employed for the analysis of LOHS accidental scenarios.

  1. Radiotoxicity and decay heat power of spent nuclear fuel of VVER type reactors at long-term storage.

    Science.gov (United States)

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Radiotoxicity and decay heat power of the spent nuclear fuel of VVER-1000 type reactors are calculated during storage time up to 300,000 y. Decay heat power of radioactive waste (radwaste) determines parameters of the heat removal system for the safe storage of spent nuclear fuel. Radiotoxicity determines the radiological hazard of radwaste after its leakage and penetration into the environment. PMID:16381764

  2. Decay Heat Removal in GEN IV Gas-Cooled Fast Reactors

    International Nuclear Information System (INIS)

    The safety goal of the current designs of advanced high-temperature thermal gas-cooled reactors (HTRs) is that no core meltdown would occur in a depressurization event with a combination of concurrent safety system failures. This study focused on the analysis of passive decay heat removal (DHR) in a GEN IV direct-cycle gas-cooled fast reactor (GFR) which is based on the technology developments of the HTRs. Given the different criteria and design characteristics of the GFR, an approach different from that taken for the HTRs for passive DHR would have to be explored. Different design options based on maintaining core flow were evaluated by performing transient analysis of a depressurization accident using the system code RELAP5-3D. The study also reviewed the conceptual design of autonomous systems for shutdown decay heat removal and recommends that future work in this area should be focused on the potential for Brayton cycle DHRs.

  3. Online calculation of the decay heat of assemblies at the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    The Fast Flux Test Facility (FFTF) is utilized by the US Department of Energy and the international community as a fast reactor research tool. Its use includes, among other things, the irradiation testing of nuclear reactor fuels and materials required for the development of commercial liquid metal reactors. The decay heat rate of assemblies irradiated in the FFTF is an important parameter in establishing the transportation, examination, and storage of irradiated assemblies. The decay heat program which is maintained on a Cray super computer along with a Symphony speadsheet program running on a personal computer (PC) were created to accommodate this need. This unique synthesis provides a method of combing the capabilities of a mainframe computer with those of a PC

  4. Study of Nuclear Decay Data Contribution to Uncertainties in Heat Load Estimations for Spent Fuel Pools

    Science.gov (United States)

    Ferroukhi, H.; Leray, O.; Hursin, M.; Vasiliev, A.; Perret, G.; Pautz, A.

    2014-04-01

    At the Paul Scherrer Institut (PSI), a methodology for nuclear data uncertainty propagation in CASMO-5M (C5M) assembly calculations is under development. This paper presents a preliminary application of this methodology to C5M decay heat calculations. Applying a stochastic sampling method, nuclear decay data uncertainties are first propagated for the cooling phase only. Thereafter, the uncertainty propagation is enlarged to gradually account for cross-section as well as fission yield uncertainties during the depletion phase. On that basis, assembly heat load uncertainties as well as total uncertainty for the entire pool are quantified for cooling times up to one year. The relative contributions from the various types of nuclear data uncertainties are in this context also estimated.

  5. Decay Heat Removal in GEN IV Gas-Cooled Fast Reactors

    Directory of Open Access Journals (Sweden)

    Lap-Yan Cheng

    2009-01-01

    Full Text Available The safety goal of the current designs of advanced high-temperature thermal gas-cooled reactors (HTRs is that no core meltdown would occur in a depressurization event with a combination of concurrent safety system failures. This study focused on the analysis of passive decay heat removal (DHR in a GEN IV direct-cycle gas-cooled fast reactor (GFR which is based on the technology developments of the HTRs. Given the different criteria and design characteristics of the GFR, an approach different from that taken for the HTRs for passive DHR would have to be explored. Different design options based on maintaining core flow were evaluated by performing transient analysis of a depressurization accident using the system code RELAP5-3D. The study also reviewed the conceptual design of autonomous systems for shutdown decay heat removal and recommends that future work in this area should be focused on the potential for Brayton cycle DHRs.

  6. Reliability analysis of safety grade decay heat removal system of Indian prototype fast breeder reactor

    International Nuclear Information System (INIS)

    The 500 MW Indian pool type Prototype Fast Breeder Reactor (PFBR), is provided with two independent and diverse Decay Heat Removal (DHR) systems viz., Operating Grade Decay Heat Removal System (OGDHRS) and Safety Grade Decay Heat Removal System (SGDHRS). OGDHRS utilizes the secondary sodium loops and Steam-Water System with special decay heat removal condensers for DHR function. The unreliability of this system is of the order of 0.1-0.01. The safety requirements of the present generation of fast reactors are very high, and specifically for DHR function the failure frequency should be less than ∼1E-7/ry. Therefore, a passive SGDHR system using four completely independent thermo-siphon loops in natural convection mode is provided to ensure adequate core cooling for all Design Basis Events. The very high reliability requirement for DHR function is achieved mainly with the help of SGDHRS. This paper presents the reliability analysis of SGDHR system. Analysis is performed by Fault Tree method using 'CRAFT' software developed at Indira Gandhi Centre for Atomic Research. This software has special features for compact representation and CCF analysis of high redundancy safety systems encountered in nuclear reactors. Common Cause Failures (CCF) are evaluated by β factor method. The reliability target for SGDHRS arrived from DHR reliability requirement and the ultimate number of demands per year (7/y) on SGDHRS is that the failure frequency should be ≤1.4E-8/de. Since it is found from the analysis that the unreliability of SGDHRS with identical loops is 5.2E-6/de and dominated by leak rates of components like AHX, DHX and sodium dump and isolation valves, options with diversity measures in important components were studied. The failure probability of SGDHRS for a design consisting of 2 types of diverse loops (Diverse AHX, DHX and sodium dump and isolation valves) is 2.1E-8/de, which practically meets the reliability requirement

  7. Fast neutron reactor safety. Reliability analysis of Phenix decay heat removal function

    International Nuclear Information System (INIS)

    This paper presents a reliability analysis of the Phenix decay heat removal function. After summarizing analysis results of sequences leading to failure of this function, the main steps in a probabilistic risk assessment are described: computation of reliability and maintenance parameters for the various systems involved, followed by probabilistic analysis of failure sequences. The extent to which the various systems contribute to the total risk is analyzed. Certain maintenance recommendations were made accordingly

  8. Testing JEFF-3.1.1 and ENDF/B-VII.1 Decay and Fission Yield Nuclear Data Libraries with Fission Pulse Neutron Emission and Decay Heat Experiments

    Science.gov (United States)

    Cabellos, O.; de Fusco, V.; Diez de la Obra, C. J.; Martinez, J. S.; Gonzalez, E.; Cano-Ott, D.; Alvarez-Velarde, F.

    2014-04-01

    The aim of this work is to test the present status of Evaluated Nuclear Decay and Fission Yield Data Libraries to predict decay heat and delayed neutron emission rate, average neutron energy and neutron delayed spectra after a neutron fission pulse. Calculations are performed with JEFF-3.1.1 and ENDF/B-VII.1, and these are compared with experimental values. An uncertainty propagation assessment of the current nuclear data uncertainties is performed.

  9. Radioactivity and decay heat generation in precambrian magmatic rocks (with the South Pamirs as an example)

    International Nuclear Information System (INIS)

    The evaluation of the heat generation share in the results of the long-living radioactive elements (RAE) decay in the Earth surface layers is accomplished on the basis of the data on the uranium and thorium concentration in the precambrian magmatic rocks of the South Pamirs. It was supposed by the calculations, that the value of the heat flux, generated by the rocks, is determined mainly by the RAE content in the Earth upper layer crust itself of 10-15 km. It is shown that the radioheat generation share is within the range of 5-10% from the measured values of the geothermal flows

  10. Decay heat removal under boiling condition in a pin-bundle geometry

    International Nuclear Information System (INIS)

    Decay heat removal capability under boiling condition was investigated using an electrically heated 37-pin bundle test section. The flow was driven by natural circulation force of the out-of-pile sodium loop SIENA in O-arai Engineering Center, PNC. As the heater power was increased, the two-phase flow regime changed from bubbly flow to slug flow and then to annular or annular mist flow. In 15 runs, dry-out was not observed in the average exit quality region of less than 0.5. The results indicated the existance of a large ''boiling window'' for low flow rate and low power conditions. (author)

  11. Meeting of Specialists on the Reliability of Decay Heat Removal Systems for Fast Reactors. Summary Report

    International Nuclear Information System (INIS)

    The Specialists Meeting on Reliability of Decay Heat Removal Systems proposed for Fast Reactors was sponsored by the UKAEA Safety & Reliability Directorate and held at Harwell between 28th April and 1st May, 1975. The meeting was attended by delegates from six countries - (USA, Federal Republic of Germany, France, Japan, USSR and the UK). A list of participants is included in an Appendix to this report. The subject matter of the meeting was concerned with the degree to which the ability to maintain decay heat removal from a fast reactor after shutdown in normal and abnormal circumstances could be guaranteed by design provisions and substantiated by reliability analysis techniques, operational testing etc. Consideration of conditions prevailing after a hypothetical core melt down incident were not included in the subject matter. The deliberations of the meeting were focussed at each working session on a defined theme and its dependant topics as shown in the detailed Agenda included in this report. Although provision had been made in the Agenda for a limited amount of discussion of the decay heat rejection problems of Gas Cooled Fast Reactors, delegates had no contributions to offer on this subject. During each session a Recording Secretary prepared a summary of the main points made by national delegates and of the resulting recommendations and conclusions. These draft summaries were made available to delegates during subsequent sessions of the meeting and approved by them for inclusion in the Summary, General Conclusions and Recommendations provided under Table of Contents (item 3 and 4)

  12. Preliminary study of the decay heat removal strategy for the gas demonstrator allegro

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Gusztáv, E-mail: gusztav.mayer@energia.mta.hu [Hungarian Academy of Sciences, Centre for Energy Research, P.O. Box 49, H-1525 Budapest (Hungary); Bentivoglio, Fabrice, E-mail: fabrice.bentivoglio@cea.fr [CEA/DEN/DM2S/STMF/LMES, F-38054, Grenoble (France)

    2015-05-15

    Highlights: • Improved decay heat removal strategy was adapted for the 75 MW ALLEGRO MOX core. • New nitrogen injection strategy was proposed for the DEC LOCA transients. • Preliminary CATHARE study shows that most of the investigated transients fulfill criteria. • Further improvements and optimizations are needed for nitrogen injection. - Abstract: The helium cooled Gas Fast Reactor (GFR) is one of the six reactor concepts selected in the frame of the Generation IV International Forum. Since no gas cooled fast reactor has ever been built, a medium power demonstrator reactor – named ALLEGRO – is necessary on the road towards the 2400 MWth GFR power reactor. The French Commissariat à l’Energie Atomique (CEA) completed a wide range of studies during the early stage of development of ALLEGRO, and later the ALLEGRO reactor concept was developed in several European Union projects in parallel with the GFR2400. The 75 MW thermal power ALLEGRO is currently developed in the frame of the European ALLIANCE project. As a result of the collaboration between CEA and the Hungarian Academy of Sciences Centre for Energy Research (MTA EK) new improvements were done in the safety approach of ALLEGRO. A complete Decay Heat Removal (DHR) strategy was devised, relying on the primary circuits as a first way to remove decay heat using pony-motors to drive the primary blowers, and on the secondary and tertiary circuits being able to work in forced or natural circulation. Three identical dedicated loops circulating in forced convection are used as a second way to remove decay heat, and these loops can circulate in natural convection for pressurized transients, providing a third way to remove decay heat in case of accidents when the primary circuit is still under pressure. The possibility to use nitrogen to enhance both forced and natural circulation is discussed. This DHR strategy is supported by a wide range of accident transient simulations performed using the CATHARE2 code

  13. Recruitment and activation of mRNA decay enzymes by two ARE-mediated decay activation domains in the proteins TTP and BRF-1

    OpenAIRE

    Lykke-Andersen, Jens; Wagner, Eileen

    2005-01-01

    In human cells, a critical pathway in gene regulation subjects mRNAs with AU-rich elements (AREs) to rapid decay by a poorly understood process. AREs have been shown to directly activate deadenylation, decapping, or 3′-to-5′ exonucleolytic decay. We demonstrate that enzymes involved in all three of these mRNA decay processes, as well as 5′-to-3′ exonucleolytic decay, associate with the protein tristetraprolin (TTP) and its homolog BRF-1, which bind AREs and activate mRNA decay. TTP and BRF-1 ...

  14. Interim storage of solidified fission products from fuel element reprocessing with utilization of obtaining post-decay heat

    International Nuclear Information System (INIS)

    It is noted that the out-lined interim store for HRW with industrial utilization of decay heat (production of saturated steam and hydrogen) does include a certain risk potential like any technical plant but that it does not represent a danger to the population living nearby. All internal and external impacts on the store result in safely triggering natural convection cooling. A further emergency cooling system is provided by the water irrigation facility so that obtaining after-heat can be safely removed under all circumstances. Therefore, there are no safety-technology arguments against any realization of the concept presented for interim storage of solidified high-level radio-active wastes. An interim store of this type may be built and operated even in densely populated regions and urban agglomerations. (orig./HP)

  15. Derivation of decay heat benchmarks for U235 and Pu239 by a least squares fit to measured data

    International Nuclear Information System (INIS)

    A least squares technique used by previous authors has been applied to an extended set of available decay heat measurements for both U235 and Pu239 to yield simultaneous fits to the corresponding beta, gamma and total decay heat. The analysis takes account of both systematic and statistical uncertainties, including correlations, via calculations which use covariance matrices constructed for the measured data. The results of the analysis are given in the form of beta, gamma and total decay heat estimates following fission pulses and a range of irradiation times in both U235 and Pu239. These decay heat estimates are considered to form a consistent set of benchmarks for use in the assessment of summation calculations. (author)

  16. Development of numerical analysis methods for natural circulation decay heat removal system applied to a large scale JSFR

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, O.; Suemori, M.; Endoh, J.; Oyama, K. [Mitsubishi FBR Systems, Inc. (MFBR), Tokyo (Japan); Koga, T. [Central Research Inst. of Electric Power Industry (CRIEPI), Chiba (Japan); Kamide, H. [Japan Atomic Energy Agency (JAEA), Ibaraki (Japan)

    2011-07-01

    A decay heat removal system utilizing passive natural circulation is applied to a large scale Japan Sodium-cooled Fast Reactor. As preparing for the future licensing, a one-dimensional flow network method and a three-dimensional numerical analysis method were developed to evaluate core cooling capability and thermal transient under decay heat removal modes after reactor trip. The one-dimensional method was applied to a water test simulating the primary system of the reactor, while the three-dimensional method was applied to the water test and a sodium test focusing on the decay heat removal system. The numerical results of both methods have turned out to agree well with the test results. And then the thermal-hydraulic behavior under a typical decay heat removal mode of the reactor has been predicted by the three-dimensional method. (author)

  17. Resonance shielding-factor cross-section processing technique validation based on tungsten decay heat experimental data

    CERN Document Server

    Cepraga, D G; Frisoni, M

    2000-01-01

    This study presents a method to obtain corrected self-shielded radiative capture cross-sections for tungsten isotopes to be used for activation calculations. The approach used is based on the application of the Bondarenko shielding factor method to the 175-group AMPX master library by means of the Bonami-Nitawl scale-4.3 sequence calculation. The ANITA-4M activation code calculates the tungsten radioisotopes production and the decay heat using the self-shielded cross-sections from ENDF/B-VI, JEF-2.2 and JENDL-3.2 data files. Two irradiation scenarios (5 min and 7 h) in the international thermonuclear experimental reactor (ITER)-like neutron flux spectrum defined by the fusion neutron source experiments are analyzed. The unshielded calculations result in discrepancy with experiment up to 70%, while the self-shielding treatment reduces drastically that discrepancy to less than few percents. In comparison to the experimental integral decay heat values provides a validation of the method used to deal with the sel...

  18. FIP Bias Evolution in a Decaying Active Region

    Science.gov (United States)

    Baker, D.; Brooks, D. H.; Démoulin, P.; Yardley, S. L.; van Driel-Gesztelyi, L.; Long, D. M.; Green, L. M.

    2015-04-01

    Solar coronal plasma composition is typically characterized by first ionization potential (FIP) bias. Using spectra obtained by Hinode’s EUV Imaging Spectrometer instrument, we present a series of large-scale, spatially resolved composition maps of active region (AR)11389. The composition maps show how FIP bias evolves within the decaying AR during the period 2012 January 4-6. Globally, FIP bias decreases throughout the AR. We analyzed areas of significant plasma composition changes within the decaying AR and found that small-scale evolution in the photospheric magnetic field is closely linked to the FIP bias evolution observed in the corona. During the AR’s decay phase, small bipoles emerging within supergranular cells reconnect with the pre-existing AR field, creating a pathway along which photospheric and coronal plasmas can mix. The mixing timescales are shorter than those of plasma enrichment processes. Eruptive activity also results in shifting the FIP bias closer to photospheric in the affected areas. Finally, the FIP bias still remains dominantly coronal only in a part of the AR’s high-flux density core. We conclude that in the decay phase of an AR’s lifetime, the FIP bias is becoming increasingly modulated by episodes of small-scale flux emergence, i.e., decreasing the AR’s overall FIP bias. Our results show that magnetic field evolution plays an important role in compositional changes during AR development, revealing a more complex relationship than expected from previous well-known Skylab results showing that FIP bias increases almost linearly with age in young ARs.

  19. Contribution to decay heat calculation: fission product mean beta and gamma assessment

    International Nuclear Information System (INIS)

    Following a reactor shutdown, after the fission chain process has completely faded out, a significant quantity of energy (around seven per cent of the total power of the reactor) continues to be generated in the core. This is known as residual power or decay heat. The principal source of this energy is due to the radioactive decay of fission products and is at any time equal to the sum of the powers released by these different nuclei (P = Σ = Pi). Each of the powers Pi is the product of three terms: the concentration of the relevant nuclide, its decay constant and its mean decay energy. The evaluation of the first two term is straightforward. On the other hand the evaluation of the mean energies presents some difficulties due to a lack of data in beta and gamma spectra of some fission products. This study intends, after a critical analysis of the current method of evaluation of the mean energies, to propose a new model for this calculation. The new model tested on several well known nuclides, has been proved correct and precise. It has then been applied to approximatively sixty nuclides among the lesser known ones. The results obtained have lead to a better prediction of both beta and gamma ray components of the residual power. Consequently, this new model, which allows to take into account the lack of beta branching ratio corresponding to the highest levels of the product nucleus in the beta decay reaction, can be adopted to replace the current method, for calculation of the mean energies of fission products, especially in the case of the lesser known nuclides

  20. Ion slip effect on unsteady Hartmann flow with heat transfer under exponential decaying pressure gradient

    Directory of Open Access Journals (Sweden)

    Hazem A. Attia

    2006-01-01

    Full Text Available The unsteady Hartmann flow of an electrically conducting, viscous, incompressible fluid bounded by two parallel nonconducting porous plates is studied with heat transfer taking the ion slip into consideration. An external uniform magnetic field and a uniform suction and injection are applied perpendicular to the plates, while the fluid motion is subjected to an exponential decaying pressure gradient. The two plates are kept at different but constant temperatures while the Joule and viscous dissipations are included in the energy equation. The effect of the ion slip and the uniform suction and injection on both the velocity and temperature distributions is examined.

  1. Passive decay heat removal by natural air convection after severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Erbacher, F.J.; Neitzel, H.J. [Forschungszentrum Karlsruhe Institut fur Angewandte Thermo- und Fluiddynamik, Karlsruhe (Germany); Cheng, X. [Technische Universitaet Karlsruhe Institut fur Stroemungslehre und Stroemungsmaschinen, Karlsruhe (Germany)

    1995-09-01

    The composite containment proposed by the Research Center Karlsruhe and the Technical University Karlsruhe is to cope with severe accidents. It pursues the goal to restrict the consequences of core meltdown accidents to the reactor plant. One essential of this new containment concept is its potential to remove the decay heat by natural air convection and thermal radiation in a passive way. To investigate the coolability of such a passive cooling system and the physical phenomena involved, experimental investigations are carried out at the PASCO test facility. Additionally, numerical calculations are performed by using different codes. A satisfying agreement between experimental data and numerical results is obtained.

  2. A value/impact assessment for alternative decay heat removal systems

    International Nuclear Information System (INIS)

    A Value/Impact assessment for several alternative decay heat removal systems has been carried out using several measures. The assessment is based on an extension of the methodology presented in the Value/Impact Handbook and includes the effects of uncertainty. The assessment was carried out as a function of site population density, existing plant features, and new plant features. Value/Impact measures based on population dose are shown to be sensitive to site, while measures which monetize and aggregate risk are less so. The latter are dominated by on-site costs such as replacement power costs. (orig.)

  3. Electron heating caused by the ion-acoustic decay instability in a finite-length system

    International Nuclear Information System (INIS)

    The ion-acoustic decay instability is investigated for a finite-length plasma with density somewhat below the cutoff density of the electromagnetic driver (napprox.0.7n/sub c/). For this regime, the heating in a very long system can overpopulate the electron tail and cause linear saturation of the low phase velocity electron plasma waves. For a short system, the instability is nonlinearly saturated at larger amplitude by ion trapping. Absorption can be significantly increased by the large-amplitude ion waves. These results compare favorably with microwave experiments

  4. Radioactive decay products in neutron star merger ejecta: heating efficiency and $\\gamma$-ray emission

    CERN Document Server

    Hotokezaka, Kenta; Tanaka, Masaomi; Bamba, Aya; Terada, Yukikatsu; Piran, Tsvi

    2015-01-01

    The radioactive decay of the freshly synthesized $r$-process nuclei ejected in compact binary mergers power optical/infrared macronovae (kilonovae) that follow these events. The light curves depend critically on the energy partition among the different products of the radioactive decay and this plays an important role in estimates of the amount of ejected $r$-process elements from a given observed signal. We study the energy partition and $\\gamma$-ray emission of the radioactive decay. We show that $20$-$50\\%$ of the total radioactive energy is released in $\\gamma$-rays on timescales from hours to a month. The number of emitted $\\gamma$-rays per unit energy interval has roughly a flat spectrum between a few dozen keV and $1$ MeV so that most of this energy is carried by $\\sim 1$ MeV $\\gamma$-rays. However at the peak of macronova emission the optical depth of the $\\gamma$-rays is $\\sim 0.02$ and most of the $\\gamma$-rays escape. The loss of these $\\gamma$-rays reduces the heat deposition into the ejecta and h...

  5. Quantification of modeling uncertainties based on scaling laws in natural circulation decay heat removal

    International Nuclear Information System (INIS)

    A Best Estimate Plus Uncertainty (BEPU) analysis is one of the good methods to estimate the uncertainty of phenomenon in a nuclear power plant dynamics. In BEPU analysis, a number of numerical analyses, in which input parameters are varied based on their probabilistic distributions, are carried out to obtain statistical characteristics of the output result. In general, the uncertainty of input parameters, such as a probabilistic distribution form and variance, are estimated based on experimental knowledge and/or engineering judgment. In the present research, we focus on a scaling law (dimensionless number) in constitutive equations from a view point of phenomenological theory. An influence of uncertainty in the dimensionless number and its dependency on BEPU analysis has been investigated. Plant dynamics analyses of Super Safe, Small and Simple (4S) reactor, being developed by Toshiba, are carried out under a natural circulation decay heat removal condition. In the analysis, uncertainties of the dimensionless numbers such as Nusselt, Reynolds, and Prandtl numbers are taken into consideration, as well as an uncertainty of decay heat power. The Latin Hypercube Sampling is applied to determine the input deck set. As a result, it is demonstrated that the parameter dependency on the output result can be revealed by using the dimensionless numbers. (author)

  6. VVER-1000/V320 decay heat analysis, involving TVS-M and TVS-A fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Petkov, P.V.; Hristov, D.V. [Kozloduy NPP, Vratsa (Bulgaria)

    2007-07-01

    MELCOR-1.8.4 is an integrated computer code, developed for severe accident calculations. It is used primarily for simulation of PWR and BWR types of reactors since the code includes an internal database, suitable for modeling of their cores inventory. Despite similarity between VVER-1000/V320 and PWR, there is still required accounting of specificities of Russian reactor design. MELCOR distinguishes 15 classes, each of them containing chemical elements with similar properties, 12 are involved in radioactive product decay. Part of it appears in the simulation of core decay heat rate after shutdown. In this paper the authors present two reactor core loadings corresponding to fuel assemblies: TVS-M and TVS-A. They have calculated decay heat after reactor shutdown from 100% and 104% of nominal power by SCALE 4.4a package. They also have estimated the amount of generated nuclides. The Newly developed Core Inventory Estimation Tool (CIET), described in this paper, written and tested previously, has been used for the evaluation of core decay heat fractions, distributed over chemical classes. Twelve curves were generated, following the same numerical procedure, implemented in MELCOR for representation of decay heat in W/kg. Comparison of curves shows deviations from the expectations. The total amount of radionuclides, separated in chemical classes, given in MELCOR Computer Code User's was compared to the ones involved in default MELCOR decay heat calculation. The results have confirmed that neglected chemical elements give 0.9% and 1.1% of total core mass for TVS-M and TVS-A and correspondingly 0.5% and 0.6% of total core decay heat.

  7. Summary report of NEPTUN investigations into the steady state thermal hydraulics of the passive decay heat removal

    International Nuclear Information System (INIS)

    During the course of steady state NEPTUN investigations, the effects of different design and operating parameters were studied; in particular: The shell design of the above core sturcture, the core power, the number of decay heat exchangers put in operation, the complete flow path blockage at the primary side of the intermediate heat exchangers, and the fluid level in the primary vessel. The findings of the NEPTUN experiments indicate that the decay heat can be safely removed by natural convection. The interwrapper flow makes an essential contribution to that behavior. The decay heat exchangers installed in the upper plenum cause a thermal stratification associated with a pronounced gradient. The vertical extent of the stratification and the quantity of the gradient are depending on the fact whether a permeable or an impermeable shell covers the above core structure. An increase of the core power or a reduction of the number of decay heat exchangers being in operation leads to a higher temperature level in the primary system but does not alter the global temperature distribution. In the case that no coolant enters the inlet windows at the primary side of the intermediate and decay heat exchangers, the core remains coolable as far as the primary vessel is filled with fluid up to a minimum level. Cold water penetrates from the upper plenum into the core and removes the decay heat. The thermal hydraulic computer code FLUTAN was applied for the three-dimensional numerical simulation of the majority of NEPTUN tests reported here. The comparison of computed against experimental data indicates a qualitatively and quantitatively satisfying agreement of the findings with respect to the field of isotherms as well as the temperature profiles in the upper plenum and within the core region of very complex geometry. (orig./HP)

  8. Radioactive decay products in neutron star merger ejecta: heating efficiency and γ-ray emission

    Science.gov (United States)

    Hotokezaka, K.; Wanajo, S.; Tanaka, M.; Bamba, A.; Terada, Y.; Piran, T.

    2016-06-01

    The radioactive decay of the freshly synthesized r-process nuclei ejected in compact binary mergers powers optical/infrared macronovae (kilonovae) that follow these events. The light curves depend critically on the energy partition among the different decay products and it plays an important role in estimates of the amount of ejected r-process elements from a given observed signal. We show that 20-50 per cent of the total radioactive energy is released in γ-rays on time-scales from hours to a month. The number of emitted γ-rays per unit energy interval has roughly a flat spectrum between a few dozen keV and 1 MeV so that most of the energy is carried by ˜1 MeV γ-rays. However, at the peak of macronova emission the optical depth of the γ-rays is ˜0.02 and most of the γ-rays escape. The loss of these γ-rays reduces the heat deposition into the ejecta and hence reduces the expected macronova signals if those are lanthanides dominated. This implies that the ejected mass is larger by a factor of 2-3 than what was previously estimated. Spontaneous fission heats up the ejecta and the heating rate can increase if a sufficient amount of transuranic nuclei are synthesized. Direct measurements of these escaping γ-rays may provide the ultimate proof for the macronova mechanisms and an identification of the r-process nucleosynthesis sites. However, the chances to detect these signals are slim with current X-ray and γ-ray missions. New detectors, more sensitive by at least a factor of 10, are needed for a realistic detection rate.

  9. Improvement of the decay heat removal characteristics of the generation IV gas-cooled fast reactor

    International Nuclear Information System (INIS)

    The majority of NPPs worldwide are currently light water reactors, using ordinary water as both coolant and moderator. (...) For the longer-term future, viz. beyond the year 2030, Research and Development is currently ongoing on Generation IV NPPs, aimed at achieving closure of the nuclear fuel cycle, and hence both drastically improved utilization of fuel resources and minimization of long-lived radioactive wastes. Since the very beginning of the international cooperation on Generation IV, viz. the year 2000, the main research interest in Europe as regards the advanced fast-spectrum systems needed for achieving complete fuel cycle closure, has been for the Sodium-cooled Fast Reactor (SFR). However, the Gas-cooled Fast Reactor (GFR) is currently considered as the main back-up solution. Like the SFR, the GFR is an efficient breeder, also able to work as iso-breeder using simply natural uranium as feed and producing waste which is predominantly in the form of fission products. The main drawback of the GFR is the difficulty to evacuate decay heat following a loss-of-coolant accident (LOCA) due to the low thermal inertia of the core, as well as to the low coolant density. The present doctoral research focuses on the improvement of decay heat removal (DHR) for the Generation-IV GFR. The reference GFR system design considered in the thesis is the 2006 CEA concept, with a power of 2400 MWth. The CEA 2006 DHR strategy foresees, in all accidental cases (independent of the system pressure), that the reactor is shut down. For high pressure events, dedicated DHR loops with blowers and heat exchangers are designed to operate when the power conversion system cannot be used to provide acceptable core temperatures under natural convection conditions. For depressurized events, the strategy relies on a dedicated small containment (called the guard containment) providing an intermediate back-up pressure. The DHR blowers, designed to work under these pressure conditions, need to be

  10. Improvement of the decay heat removal characteristics of the generation IV gas-cooled fast reactor

    International Nuclear Information System (INIS)

    Gas cooling in nuclear power plants (NPPs) has a long history, the corresponding reactor types developed in France, the UK and the US having been thermal neutron spectrum systems using graphite as the moderator. The majority of NPPs worldwide, however, are currently light water reactors, using ordinary water as both coolant and moderator. These NPPs - of the so-called second generation - will soon need replacement, and a third generation is now being made available, offering increased safety while still based on light water technology. For the longer-term future, viz. beyond the year 2030, R and D is currently ongoing on Generation IV NPPs, aimed at achieving closure of the nuclear fuel cycle, and hence both drastically improved utilization of fuel resources and minimization of long-lived radioactive wastes. Like the SFR, the GFR is an efficient breeder, also able to work as iso-breeder using simply natural uranium as feed and producing waste which is predominantly in the form of fission products. The main drawback of the GFR is the difficulty to evacuate decay heat following a loss-of-coolant accident (LOCA) due to the low thermal inertia of the core, as well as to the low coolant density. The present doctoral research focuses on the improvement of decay heat removal (DHR) for the Generation-IV GFR. The reference GFR system design considered in the thesis is the 2006 CEA concept, with a power of 2400 MWth. The CEA 2006 DHR strategy foresees, in all accidental cases (independent of the system pressure), that the reactor is shut down. For high pressure events, dedicated DHR loops with blowers and heat exchangers are designed to operate when the power conversion system cannot be used to provide acceptable core temperatures under natural convection conditions. For de-pressurized events, the strategy relies on a dedicated small containment (called the guard containment) providing an intermediate back-up pressure. The DHR blowers, designed to work under these pressure

  11. Gap between active and passive solar heating

    Energy Technology Data Exchange (ETDEWEB)

    Balcomb, J.D.

    1985-01-01

    The gap between active and passive solar could hardly be wider. The reasons for this are discussed and advantages to narrowing the gap are analyzed. Ten years of experience in both active and passive systems are reviewed, including costs, frequent problems, performance prediction, performance modeling, monitoring, and cooling concerns. Trends are analyzed, both for solar space heating and for service water heating. A tendency for the active and passive technologies to be converging is observed. Several recommendations for narrowing the gap are presented.

  12. Reactor decay heat in 239Pu: solving the γ discrepancy in the 4-3000-s cooling period.

    Science.gov (United States)

    Algora, A; Jordan, D; Taín, J L; Rubio, B; Agramunt, J; Perez-Cerdan, A B; Molina, F; Caballero, L; Nácher, E; Krasznahorkay, A; Hunyadi, M D; Gulyás, J; Vitéz, A; Csatlós, M; Csige, L; Aysto, J; Penttilä, H; Moore, I D; Eronen, T; Jokinen, A; Nieminen, A; Hakala, J; Karvonen, P; Kankainen, A; Saastamoinen, A; Rissanen, J; Kessler, T; Weber, C; Ronkainen, J; Rahaman, S; Elomaa, V; Rinta-Antila, S; Hager, U; Sonoda, T; Burkard, K; Hüller, W; Batist, L; Gelletly, W; Nichols, A L; Yoshida, T; Sonzogni, A A; Peräjärvi, K

    2010-11-12

    The β feeding probability of (102,104,105,106,107)Tc, 105Mo, and 101Nb nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the γ component of the decay heat for 239Pu in the 4-3000 s range. PMID:21231223

  13. Reactor Decay Heat in 239Pu: Solving the Gamma Discrepancy in the 4–3000-s Cooling Period

    Energy Technology Data Exchange (ETDEWEB)

    Algora, A.; Sonzogni, A.; Algora,A.; Jordan,D.; Tain,J.L.; Rubio,B.; Agramunt,J.; Perez-Cerdan,A.B.; Molina,F; Caballero,L.; Nacher,E.; Krasznahorkay,A.; Hunyadi,M.D.; Gulyas,J; Vitez,A.; Csatlos,M.; Csige,L.; Aysto,J.; Penttila,H.; Moore,I.D.; Eronen,T.; Jokinen,A.; Nieminen,A.; Hakala,J.; Karvonen,P.; Kankainen,A.; Saastamoinen,A.; Rissanen,J.; Kessler,T.; Weber,C.; Ronkainen,J.; Rahaman,S.; Elomaa,V.; Rinta-Antila,S.; Hager,U.; Sonoda,T.; Burkard,K.; Huller,W.; Batist,L.; Gelletly,W.; Nichols,A.L.; Yoshida,T.; Sonzogni,A.A.; Perajarvi,K.

    2010-11-08

    The {beta} feeding probability of {sup 102,104,105,106,107}Tc, {sup 105}Mo, and {sup 101}Nb nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the {gamma} component of the decay heat for {sup 239}Pu in the 4-3000 s range.

  14. Modeling the decay of energy containing eddies: A source of solar wind heating

    Science.gov (United States)

    Hossain, M.; Gray, P. C.; Pontius, D. H.; Matthaeus, W. H.; Oughton, S.

    1995-01-01

    To understand the solar wind heating and acceleration mechanisms one needs to understand the decay of energy containing eddies. With this goal in mind, attempts have been made to extend the fluid dynamic phenomenology of large scale quasi-equilibrium to the case of magnetohydrodynamics. Matthaeus et al. have proposed a model for the inhomogeneous transport and decay of five mean variables, namely, two mean square Elsasser variables z(exp 2) (sub +/-) their correlation lengths, and the difference between the kinetic and magnetic energies. We test the validity of this model in the simplified case of homogeneous turbulence simulated in a periodic box. We propose a class of models and show that they may fit the simulation satisfactorily. Analytic solutions of this class of model reveal their inherent properties and demonstrate the difficulties associated with finite cross helicity. It is noted that adjustments are required to make the simplest models, which are based upon isotropic turbulence, scale properly with respect to the strength of the mean magnetic field. This can be interpreted as due to anisotropic turbulence, which can be modelled by simple parameterization in the phenomenology.

  15. The Decay of Stellar Dynamos and X-ray Activity

    CERN Document Server

    Wright, Nicholas J; Civano, Francesca

    2010-01-01

    Existing stellar X-ray surveys suggest major problems in our understanding of the evolution of stellar magnetic activity in solar and late-type stars, reaching conflicting conclusions over the rate of decay of X-ray activity and the spectral types responsible. We are confronting these discrepancies with a new model of the expected stellar X-ray luminosity distribution, combining a Galactic population synthesis model with current theories for rotational spin- down and the rotation - activity relation for the stellar magnetic dynamo. Here we test our model using new observations of the stellar content of the Chandra COSMOS survey, for which 60 new stellar X-ray sources are identified from the thin disk and Galactic halo populations. Our model is in approximate agreement with the observed X-ray luminosity distribution and the distribution of spectral types responsible. However, slight differences in the form of the X-ray luminosity distribution exist that may hint at problems in our understanding of stellar X-ra...

  16. Reliability study of a special decay heat removal system of a gas-cooled fast reactor demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Burgazzi, Luciano, E-mail: luciano.burgazzi@enea.it

    2014-12-15

    The European roadmap toward the development of generation IV concepts addresses the safety and reliability assessment of the special system designed for decay heat removal of a gas-cooled fast reactor demonstrator (GFRD). The envisaged system includes the combination of both active and passive means to accomplish the fundamental safety function. Failure probabilities are calculated on various system configurations, according to either pressurized or depressurized accident events under investigation, and integrated with probabilities of occurrence of corresponding hardware components and natural circulation performance assessment. The analysis suggests the improvement of measures against common cause failures (CCF), in terms of an appropriate diversification among the redundant systems, to reduce the system failure risk. Particular emphasis is placed upon passive system reliability assessment, being recognized to be still an open issue, and the approach based on the functional reliability is adopted to address the point. Results highlight natural circulation as a challenging factor for the decay heat removal safety function accomplishment by means of passive devices. With the models presented here, the simplifying assumptions and the limited scenarios considered according to the level of definition of the design, where many systems are not yet established, one can conclude that attention has to be paid to the functional aspects of the passive system, i.e. the ones not pertaining to the “hardware” of the system. In this article the results of the analysis are discussed, where the effects of the analytical assumptions, design options, accident managements on the reliability are examined. The design diversity of the components undergoing CCFs can be effective for the improvement and some accident management measures are also possible by making use of the long grace period in GFRD.

  17. Analysis of integral circulation and decay heat removal experiments in the lead-bismuth CIRCE facility with RELAP5 code

    International Nuclear Information System (INIS)

    In this paper, the results of the post-test analysis of some integral circulation experiments conducted on the lead-bismuth CIRCE facility are presented in comparison with the experimental data. These experiments include the simulation of unprotected loss of flow and unprotected loss of heat sink transients in a pool-type heavy liquid metal reactor. Furthermore, the results of the pre-test analysis of a protected loss of heat sink and flow transient with decay heat removal by a heat exchanger immersed in the pool and operating in natural circulation is presented. All transient analyses have been performed with the RELAP5 thermal-hydraulic code. (author)

  18. Dual active surface heat flux gage probe

    Science.gov (United States)

    Liebert, Curt H.; Kolodziej, Paul

    1995-02-01

    A unique plug-type heat flux gage probe was tested in the NASA Ames Research Center 2x9 turbulent flow duct facility. The probe was fabricated by welding a miniature dual active surface heat flux gage body to the end of a hollow metal cylindrical bolt containing a metal inner tube. Cooling air flows through the inner tube, impinges onto the back of the gage body and then flows out through the annulus formed between the inner tube and the hollow bolt wall. Heat flux was generated in the duct facility with a Huels arc heater. The duct had a rectangular cross section and one wall was fabricated from 2.54 centimeter thick thermal insulation rigid surface material mounted onto an aluminum plate. To measure heat flux, the probe was inserted through the plate and insulating materials with the from of the gage located flush with the hot gas-side insulation surface. Absorbed heat fluxes measured with the probe were compared with absorbed heat fluxes measured with six water-cooled reference calorimeters. These calorimeters were located in a water-cooled metal duct wall which was located across from the probe position. Correspondence of transient and steady heat fluxes measured with the reference calorimeters and heat flux gage probe was generally within a satisfactory plus or minus 10 percent. This good correspondence was achieved even though the much cooler probe caused a large surface temperature disruption of 1000K between the metal gage and the insulation. However, this temperature disruption did not seriously effect the accuracy of the heat flux measurement. A current application for dual active surface heat flux gages is for transient and steady absorbed heat flux, surface temperature and heat transfer coefficient measurements on the surface of an oxidizer turbine inlet deflector operating in a space shuttle test bed engine.

  19. CdWO4 scintillating bolometer for Double Beta Decay: Light and Heat anticorrelation, light yield and quenching factors

    OpenAIRE

    Arnaboldi, C.; Beeman, J.W.; Cremonesi, O.; Gironi, L.; M. Pavan; Pessina, G.(Sezione INFN di Milano Bicocca, Milan, Italy); Pirro, S.(INFN-Laboratori Nazionali del Gran Sasso, Assergi, 67010 , L’Aquila, Italy); Previtali, E.

    2010-01-01

    Abstract We report the performances of a 0.51 kg CdWO4 scintillating bolometer to be used for future Double Beta Decay Experiments. The simultaneous read-out of the heat and the scintillation light allows to discriminate between different interacting particles aiming at the disentanglement and the reduction of background contribution, key issue for next generation experiments. We will describe the observed anticorrelation between the heat and the light signal and we will show how t...

  20. BWR spent fuel storage cask performance test. Volume 2. Pre- and post-test decay heat, heat transfer, and shielding analyses

    International Nuclear Information System (INIS)

    This report describes the decay heat, heat transfer, and shielding analyses conducted in support of performance testing of a Ridhihalgh, Eggers and Associates REA 2033 boiling water reactor (BWR) spent fuel storage cask. The cask testing program was conducted for the US Department of Energy (DOE) Commercial Spent Fuel Management Program by the Pacific Northwest Laboratory (PNL) and by General Electric at the latters' Morris Operation (GE-MO) as reported in Volume I. The analyses effort consisted of performing pretest calculations to (1) select spent fuel for the test; (2) symmetrically load the spent fuel assemblies in the cask to ensure lateral symmetry of decay heat generation rates; (3) optimally locate temperature and dose rate instrumentation in the cask and spent fuel assemblies; and (4) evaluate the ORIGEN2 (decay heat), HYDRA and COBRA-SFS (heat transfer), and QAD and DOT (shielding) computer codes. The emphasis of this second volume is on the comparison of code predictions to experimental test data in support of the code evaluation process. Code evaluations were accomplished by comparing pretest (actually pre-look, since some predictions were not completed until testing was in progress) predictions with experimental cask testing data reported in Volume I. No attempt was made in this study to compare the two heat transfer codes because results of other evaluations have not been completed, and a comparison based on one data set may lead to erroneous conclusions

  1. Integrated assessment approach to ensure removal of decay heat with RCW out of service

    International Nuclear Information System (INIS)

    In the unusual event that Recirculated Cooling Water System of a CANDU NPP is drained for maintenance or generally incapacitated and the reactor is in the Guaranteed Shutdown State, an alternative source of cooling water is required to remove decay heat. For the Cernavoda Unit 1 NPP, CNE-PROD assessed and proposed a novel arrangement to address this issue, prepared a design, and requested AECL to assess the proposed approach. As part of the assessment, AECL developed and performed an integrated approach that brought together a variety of design, operational, maintenance and safety considerations. First, a simplified hydraulic analysis was performed, the heat removal requirements of the system were reviewed and alternative heat sinks were evaluated. Then, the maintenance and operational implications were considered in detail, using AECL's Systematic Assessment of Maintenance (SAM) process. This included a detailed assessment of failure modes of interest and associated effects (Failure Modes and Effects Analysis). This assessment included consideration of the impact on operational chemistry. In addition, the safety implications (potential for human error and safety consequences of failure) were reviewed. Based upon the system requirements, hydraulic assessment, and maintenance review, several alternatives or improvements to the CNE-PROD proposal were developed. In addition, a number of operational suggestions, as well as additional concerns and considerations were identified. Finally, potential alternative solutions were looked at based upon previous AECL experience. This paper will describe the novel CNE-PROD arrangement and provide an overview of the integrated assessment approach taken by AECL (using Plant Life Management technologies) to evaluate the proposed arrangement and to identify additional considerations. (author)

  2. Neutronic and thermo-hydraulic analyses of a small, long-life HTGR for passive decay-heat removal

    International Nuclear Information System (INIS)

    Since the accident at Fukushima Daiichi Nuclear Power Plant in 2011, design concepts for nuclear reactors have been reconsidered with much greater emphasis placed upon passive systems for decay-heat removal. By considering this issue, the design parameter conditions for high temperature gas-cooled reactors (HTGRs) with passive safety features of decay-heat removal were obtained by residual-heat transfer calculation using equations for fundamental heat transfer mechanisms in our previous works. In the present study, the appropriate size of reactor core for a 100 MWt reactor operating at 1123 K of the initial core temperature was found using the conditions. Consequently, neutronics and thermo-hydraulic analyses for the proposed reactor core were performed and the proper optimizations to control the excess reactivity and flatten the change in power peaking factor during operation were done successfully. By the systematic method to decide the core design which satisfies the condition for passive decay-heat removal, a long-life small HTGR concept whose excess reactivity was small during the operation was shown. The small excess reactivity is a significant advantage from the view point of safety in reactivity accident. (author)

  3. Experimental and analytical studies for the validation of HTR-VGD and primary cell passive decay heat removal. Supplement. Calculations

    International Nuclear Information System (INIS)

    The alternative concept for a modular HTR-reactor design by Siempelkamp, Krefeld, using a prestressed cast iron vessel (VGD) combined with a cast iron/concrete module for the primary cell with integrated passive decay heat removal system was fully qualified with respect to operational and accidental thermal loads. The main emphasis was to confirm and validate the passive decay heat removal capability. An experimental facility (INWA) was designed, instrumented and operated with an appropriate electrical heating system simulating steady-state operational and transient accidental thermal loads. The experiments were accompanied by extensive computations concerning the combination of conductive, radiative and convective energy transport mechanisms in the different components of the VGD/primary cell structures, as well as elastic-plastic stress analyses of the VGD. In addition, a spectrum of potential alternatives for passive energy removed options have been parametrically examined. The experimental data clearly demonstrate that the proposed Siempelkamp-design is able to passively and safely remove the decay heat for operational and accidental conditions without invalidating technological important thermal limits. This also holds in case of failures of both the natural convection system and ultimate heat sink by outside concrete water film cooling. (orig./HP)

  4. Shutdown Decay Heat Removal analysis of a Westinghouse 3-loop pressurized water reactor: Case study

    International Nuclear Information System (INIS)

    This is one of six case studies for USI A-45 Decay Heat Removal (DHR) Requirements. The purpose of this study is to identify any potential vulnerabilities in the DHR systems of a typical Westinghouse 3-loop PWR, to suggest possible modifications to improve the DHR capability, and to assess the value and impact of the most promising alternatives to the existing DHR systems. The systems analysis considered small LOCAs and transient internal initiating events, and seismic, fire, extreme wind, internal and external flood, and lightning external events. A full-scale systems analysis was performed with detailed fault trees and event trees including support system dependencies. The system analysis results were extrapolated into release categories using applicable past PRA phenomenological results and improved containment failure mode probabilities. Public consequences were estimated using site specific CRAC2 calculations. The Value-Impact (VI) analysis of possible alternatives considered both onsite and offsite impacts arriving at several risk measures such as averted population dose out to a 50-mile radius and dollars per person rem averted. Uncertainties in the VI analysis are discussed and the issues of feed and bleed and secondary blowdown are analyzed

  5. Numerical investigation of multidimensional natural circulation phenomenon in passive safety systems for decay heat removal in large pools

    International Nuclear Information System (INIS)

    Many advanced designs of nuclear reactors adopt a methodology of passive safety systems in which the decay heat generated from a reactor is transferred by natural circulation into large pool of water called the Gravity Driven Water Pool (GDWP). Three-dimensional convection flows develop, which in turn affect the heat transfer process and hence the temperature pattern. The heat transfer process can get compromised by the possible stratification of the temperature. The objective of this study is to investigate the transient multidimensional natural circulation phenomenon in GDWP having total volume of 9247 m3 using open source CFD code (OpenFOAM-2.2). In order to reduce the thermal stratification, various geometrical modifications have been incorporated on the heat exchanger design, such as distributing and submergence of heat source; provision of passive elements such as draft tube. A detailed CFD analysis has confirmed the mitigation of thermal stratification phenomenon. (author)

  6. Development of margin assessment methodology of decay heat removal function against external hazards. (2) Tornado PRA methodology

    International Nuclear Information System (INIS)

    Probabilistic Risk Assessment (PRA) for external events has been recognized as an important safety assessment method after the TEPCO's Fukushima Daiichi nuclear power station accident. The PRA should be performed not only for earthquake and tsunami which are especially key events in Japan, but also the PRA methodology should be developed for the other external hazards (e.g. tornado). In this study, the methodology was developed for Sodium-cooled Fast Reactors paying attention to that the ambient air is their final heat sink for removing decay heat under accident conditions. First, tornado hazard curve was estimated by using data recorded in Japan. Second, important structures and components for decay heat removal were identified and an event tree resulting in core damage was developed in terms of wind load and missiles (i.e. steel pipes, boards and cars) caused by a tornado. Main damage cause for important structures and components is the missiles and the tornado missiles that can reach those components and structures placed on high elevations were identified, and the failure probabilities of the components and structures against the tornado missiles were calculated as a product of two probabilities: i.e., a probability for the missiles to enter the intake or outtake in the decay heat removal system, and a probability of failure caused by the missile impacts. Finally, the event tree was quantified. As a result, the core damage frequency was enough lower than 10-10/ry. (author)

  7. Development of a water boil-off spent-fuel calorimeter system. [To measure decay heat generation rate

    Energy Technology Data Exchange (ETDEWEB)

    Creer, J.M.; Shupe, J.W. Jr.

    1981-05-01

    A calorimeter system was developed to measure decay heat generation rates of unmodified spent fuel assemblies from commercial nuclear reactors. The system was designed, fabricated, and successfully tested using the following specifications: capacity of one BWR or PWR spent fuel assembly; decay heat generation range 0.1 to 2.5 kW; measurement time of < 12 h; and an accuracy of +-10% or better. The system was acceptance tested using a dc reference heater to simulate spent fuel assembly heat generation rates. Results of these tests indicated that the system could be used to measure heat generation rates between 0.5 and 2.5 kW within +- 5%. Measurements of heat generation rates of approx. 0.1 kW were obtained within +- 15%. The calorimeter system has the potential to permit measurements of heat generation rates of spent fuel assemblies and other devices in the 12- to 14-kW range. Results of calorimetry of a Turkey Point spent fuel assembly indicated that the assembly was generating approx. 1.55 kW.

  8. BWR spent fuel storage cask performance test. Volume 1. Cask handling experience and decay heat, heat transfer, and shielding data

    International Nuclear Information System (INIS)

    This report documents a heat transfer and shielding performance test conducted on a Ridihalgh, Eggers and Associates REA 2023 boiling water reactor (BWR) spent fuel storage cask. The testing effort consisted of three parts: pretest preparations, performance testing, and post-test activities. Pretest preparations included conducting cask handling dry runs and characterizing BWR spent fuel assemblies from Nebraska Public Power District's Cooper Nuclear Station. The performance test matrix included 14 runs consisting of two loadings, two cask orientations, and three backfill environments. Post-test activities included calorimetry and axial radiation scans of selected fuel assemblies, in-basin sipping of each assembly, crud collection, video and photographic scans, and decontamination of the cask interior and exterior

  9. BWR spent fuel storage cask performance test. Volume 1. Cask handling experience and decay heat, heat transfer, and shielding data

    Energy Technology Data Exchange (ETDEWEB)

    McKinnon, M.A.; Doman, J.W.; Tanner, J.E.; Guenther, R.J.; Creer, J.M.; King, C.E.

    1986-02-01

    This report documents a heat transfer and shielding performance test conducted on a Ridihalgh, Eggers and Associates REA 2023 boiling water reactor (BWR) spent fuel storage cask. The testing effort consisted of three parts: pretest preparations, performance testing, and post-test activities. Pretest preparations included conducting cask handling dry runs and characterizing BWR spent fuel assemblies from Nebraska Public Power District's Cooper Nuclear Station. The performance test matrix included 14 runs consisting of two loadings, two cask orientations, and three backfill environments. Post-test activities included calorimetry and axial radiation scans of selected fuel assemblies, in-basin sipping of each assembly, crud collection, video and photographic scans, and decontamination of the cask interior and exterior.

  10. Reliability Assessment of 2400 MWth Gas-Cooled Fast Reactor Natural Circulation Decay Heat Removal in Pressurized Situations

    Directory of Open Access Journals (Sweden)

    C. Bassi

    2008-01-01

    Full Text Available As the 2400 MWth gas-cooled fast reactor concept makes use of passive safety features in combination with active safety systems, the question of natural circulation decay heat removal (NCDHR reliability and performance assessment into the ongoing probabilistic safety assessment in support to the reactor design, named “probabilistic engineering assessment” (PEA, constitutes a challenge. Within the 5th Framework Program for Research and Development (FPRD of the European Community, a methodology has been developed to evaluate the reliability of passive systems characterized by a moving fluid and whose operation is based on physical principles, such as the natural circulation. This reliability method for passive systems (RMPSs is based on uncertainties propagation into thermal-hydraulic (T-H calculations. The aim of this exercise is finally to determine the performance reliability of the DHR system operating in a “passive” mode, taking into account the uncertainties of parameters retained for thermal-hydraulical calculations performed with the CATHARE 2 code. According to the PEA preliminary results, exhibiting the weight of pressurized scenarios (i.e., with intact primary circuit boundary for the core damage frequency (CDF, the RMPS exercise is first focusing on the NCDHR performance at these T-H conditions.

  11. Dynamic simulation of the air-cooled decay heat removal system of the German KNK-II experimental breeder reactor

    International Nuclear Information System (INIS)

    A Dump Heat Exchanger and associated feedback control system models for decay heat removal in the German KNK-II experimental fast breeder reactor are presented. The purpose of the controller is to minimize temperature variations in the circuits and, hence, to prevent thermal shocks in the structures. The basic models for the DHX include the sodium-air thermodynamics and hydraulics, as well as a control system. Valve control models for the primary and intermediate sodium flow regulation during post shutdown conditions are also presented. These models have been interfaced with the SSC-L code. Typical results of sample transients are discussed

  12. Incresing antioxidant activity and reducing decay of blueberries by essential oils

    Science.gov (United States)

    Several naturally occurring essential oils including carvacrol, anethole, cinnamaldehyde, cinnamic acid, perillaldehyde, linalool, and p-cymene were evaluated for their effectiveness in reducing decay and increasing antioxidant levels and activities in ‘Duke’ blueberries (Vaccinium corymbosum). Carv...

  13. Low-latitude coronal holes, decaying active regions and global coronal magnetic structure

    CERN Document Server

    Petrie, Gordon

    2013-01-01

    We study the relationship between decaying active region magnetic fields, coronal holes and the global coronal magnetic structure using Global Oscillations Network Group (GONG) synoptic magnetograms, Solar Terrestrial RElations Observatory (STEREO) extreme ultra-violet (EUV) synoptic maps and coronal potential-field source-surface (PFSS) models. We analyze 14 decaying regions and associated coronal holes occurring between early 2007 and late 2010, four from cycle 23 and 10 from cycle 24. We investigate the relationship between asymmetries in active regions' positive and negative magnetic intensities, asymmetric magnetic decay rates, flux imbalances, global field structure and coronal hole formation. Whereas new emerging active regions caused changes in the large-scale coronal field, the coronal fields of the 14 decaying active regions only opened under the condition that the global coronal structure remained almost unchanged. This was because the dominant slowly-varying, low-order multipoles prevented opposin...

  14. Decay Heat Analyses after Thermal-Neutron Fission of {sup 235}U and {sup 239}Pu by SCALE-6.1.3 with Recently Available Fission Product Yield Data

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Heon; Gil, Choong-Sup; Lee, Young-Ouk [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The heat reaches about 1.5% after one hour and falls to 0.4% after a day. After a week it will be about 0.2%. The reactor, however, still requires further cooling for several years to keep the fuel rods safe. In general, the decay heat in the reactors can be calculated using a summation calculation method, which is simply the sum of the activities of the fission products produced during the fission process and after the reactor shutdown weighted by the mean decay energies. Consequently, the method is strongly dependent on the available nuclear structure data. Nowadays, the method has been implemented in various burnup and depletion programs such as ORIGEN and CINDER. In this study, the decay heat measurements after thermal-neutron fission of {sup 235}U and {sup 239}Pu have been evaluated by the ORIGEN-S with the decay data and fission product yield libraries included in the SCALE-6.1.3 software package. The new libraries were applied to the decay heat calculations, and the results were compared with those by the ORIGEN reference calculation. The decay heat measurements for very short cooling times after thermal-neutron fission of {sup 235}U and {sup 239}Pu have been evaluated by the ORIGEN-S summation calculation. The reference calculation results by the latest ORIGEN data libraries of the SCALE-6.1.3 have been validated with the measurements by ORNL and Studsvik. In addition, the generation of the new ORIGEN yield libraries has been completed based on the ENDF/B-VII.1, JEFF-3.1.1, JENDL/FPY-2011, and JENDL-4.0. The new libraries have been successfully applied to the decay heat calculations and comparative analyses have been devoted to verifying the importance of the fission product yield data when estimating the decay heat values for each isotope in a very short time. The decay data library occupies an important position in the ORIGEN summation calculation along with the fission product yield library.

  15. CFD modeling and thermal-hydraulic analysis for the passive decay heat removal of a sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Research highlights: → The COOLOD/N2 and PARET/ANL codes were used for a steady-state thermal-hydraulic and safety analysis of the 2 MW TRIGA MARK II reactor located at the Nuclear Studies Center of Maamora (CENM), Morocco. → The main objective of this study is to ensure the safety margins of different safety related parameters by steady-state calculations at full power level (2 MW). → The most important conclusion is that all obtained values of DNBR, fuel center and surface temperature, cladding surface temperature and coolant temperature across the hottest channel are largely far to compromise safety of the reactor. - Abstract: In this study, a pool-typed design similar to sodium-cooled fast reactor (SFR) of the fourth generation reactors has been modeled using CFD simulations to investigate the characteristics of a passive mechanism of Shutdown Heat Removal System (SHRS). The main aim is to refine the reactor pool design in terms of temperature safety margin of the sodium pool. Thus, an appropriate protection mechanism is maintained in order to ensure the safety and integrity of the reactor system during a shutdown mode without using any active heat removal system. The impacts on the pool temperature are evaluated based on the following considerations: (1) the aspect ratio of pool diameter to depth, (2) the values of thermal emissivity of the surface materials of reactor and guard vessels, and (3) innerpool liner and core periphery structures. The computational results show that an optimal pool design in geometry can reduce the maximum pool temperature down to ∼551 oC which is substantially lower than ∼627 oC as calculated for the reference case. It is also concluded that the passive Reactor Air Cooling System (RACS) is effective in removing decay heat after shutdown. Furthermore, thermal radiation from the surface of the reactor vessel is found to be important; and thus, the selection of the vessel surface materials with a high emissivity would be a

  16. CFD modeling and thermal-hydraulic analysis for the passive decay heat removal of a sodium-cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hung, T.C., E-mail: tchung@ntut.edu.t [Department of Mechanical Engineering, National Taipei University of Technology, 1, Sec. 3, Chung-hsiao E. Rd., Taipei 10608, Taiwan (China); Dhir, V.K. [Department of Mechanical and Aerospace Engineering, UCLA, CA (United States); Chang, J.C. [Graduate Institute of Mechanical and Electrical Engineering, National Taipei University of Technology, Taiwan (China); Wang, S.K. [Department of Mechanical and Automation Engineering, I-Shou University, Taiwan (China)

    2011-01-15

    Research highlights: The COOLOD/N2 and PARET/ANL codes were used for a steady-state thermal-hydraulic and safety analysis of the 2 MW TRIGA MARK II reactor located at the Nuclear Studies Center of Maamora (CENM), Morocco. The main objective of this study is to ensure the safety margins of different safety related parameters by steady-state calculations at full power level (2 MW) The most important conclusion is that all obtained values of DNBR, fuel center and surface temperature, cladding surface temperature and coolant temperature across the hottest channel are largely far to compromise safety of the reactor. - Abstract: In this study, a pool-typed design similar to sodium-cooled fast reactor (SFR) of the fourth generation reactors has been modeled using CFD simulations to investigate the characteristics of a passive mechanism of Shutdown Heat Removal System (SHRS). The main aim is to refine the reactor pool design in terms of temperature safety margin of the sodium pool. Thus, an appropriate protection mechanism is maintained in order to ensure the safety and integrity of the reactor system during a shutdown mode without using any active heat removal system. The impacts on the pool temperature are evaluated based on the following considerations: (1) the aspect ratio of pool diameter to depth, (2) the values of thermal emissivity of the surface materials of reactor and guard vessels, and (3) innerpool liner and core periphery structures. The computational results show that an optimal pool design in geometry can reduce the maximum pool temperature down to {approx}551 {sup o}C which is substantially lower than {approx}627 {sup o}C as calculated for the reference case. It is also concluded that the passive Reactor Air Cooling System (RACS) is effective in removing decay heat after shutdown. Furthermore, thermal radiation from the surface of the reactor vessel is found to be important; and thus, the selection of the vessel surface materials with a high emissivity

  17. Correlation of Coronal Plasma Properties and Solar Magnetic Field in a Decaying Active Region

    Science.gov (United States)

    Ko, Yuan-Kuen; Young, Peter R.; Muglach, Karin; Warren, Harry P.; Ugarte-Urra, Ignacio

    2016-08-01

    We present the analysis of a decaying active region observed by the EUV Imaging Spectrometer on Hinode during 2009 December 7–11. We investigated the temporal evolution of its structure exhibited by plasma at temperatures from 300,000 to 2.8 million degrees, and derived the electron density, differential emission measure, effective electron temperature, and elemental abundance ratios of Si/S and Fe/S (as a measure of the First Ionization Potential (FIP) Effect). We compared these coronal properties to the temporal evolution of the photospheric magnetic field strength obtained from the Solar and Heliospheric Observatory Michelson Doppler Imager magnetograms. We find that, while these coronal properties all decreased with time during this decay phase, the largest change was at plasma above 1.5 million degrees. The photospheric magnetic field strength also decreased with time but mainly for field strengths lower than about 70 Gauss. The effective electron temperature and the FIP bias seem to reach a “basal” state (at 1.5 × 106 K and 1.5, respectively) into the quiet Sun when the mean photospheric magnetic field (excluding all areas <10 G) weakened to below 35 G, while the electron density continued to decrease with the weakening field. These physical properties are all positively correlated with each other and the correlation is the strongest in the high-temperature plasma. Such correlation properties should be considered in the quest for our understanding of how the corona is heated. The variations in the elemental abundance should especially be considered together with the electron temperature and density.

  18. Sodium experiment on fully natural circulation systems for decay heat removal in Japan sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Fully natural circulation system is adopted in a decay heat removal system (DHRS) of Japan Sodium Cooled Fast Reactor (JSFR). The DHRS of JSFR consists of one unit of DRACS (direct reactor auxiliary cooling system), which has a dipped heat exchanger in the reactor vessel and two units of PRACS, which has a heat exchanger in a primary-side inlet plenum of IHX in each loop. Sodium experiments were carried out for heat transfer characteristics of a sodium-sodium heat exchanger of PRACS and start-up transient of the DHRS loop with parameters of pressure loss coefficients in the loops. The transient experiments for the start-up of DHRS loop showed that quick increase of natural draft in the air duct followed by smooth increase of sodium flow rate in the DHRS loop. Influences of the pressure loss coefficients in the primary loop and the DHRS loop were limited on the core temperature and also heat removal of PRACS, respectively due to recovery of natural circulation head via the increase of temperature difference in each loop. (author)

  19. Evaluation of the heat-storage capability of shallow aquifers using active heat tracer tests and Fiber-Optics Distributed-Temperature-Sensing

    Science.gov (United States)

    Suibert Oskar Seibertz, Klodwig; Chirila, Marian Andrei; Bumberger, Jan; Dietrich, Peter; Vienken, Thomas

    2015-04-01

    In the course of the energy transition, geothermal energy storage and heat generation and cooling have proven to be environmental friendly alternatives to conventional energy. However, to ensure sustain usage, the heat transport behavior of aquifers and its distribution has to be studied. A tool to achieve this is the active heat tracer test, eg. Leaf et al. (2012). If active heat tracer tests are combined with in aquifer heat testing via electric heating-cables, eg. Liu et al. (2013), it is possible to observe heat transport and temperature signal decay without disturbing the original pressure field within the aquifer. In this field study a two channel High-Resolution-Fiber-Optic-Distributed-Temperature-Sensing and Pt100 were used to measure temperature signals within in two wells of 1.4 m distance, where the temperature difference was generated using a self regulating heating cable in the upstream well. High resolution Distributed-Temperature-Sensing measurements were achieved by coiling the fiber around screened plastic tubes. The upstream well was also used to observe heating (Δ Tmax approx. 24K) and temperature signal decay, while the downstream well was used to observe heat transport between both wells. The data was analyzed and compared to thermal conductivity of soil samples and Direct-Push (DP) Electrical-Conductivity-Logging and DP Hydraulic-Profiling results. The results show good agreement between DP data and temperature measurements proving the active heat tracer test is a suitable tool for providing reliable information on aquifer heat-storage capability. References Leaf, A.T., Hart, D.J., Bahr, J.M.: Active Thermal Tracer Tests for Improved Hydrostratigraphic Characterization. Ground Water, vol. 50, 2012 Liu, G., Knobbe, S., Butler, J.J.Jr.: Resolving centimeter-scale flows in aquifers and their hydrostratigraphic controls. Geophysical Research Letters, vol. 40, 2013

  20. The AU-rich element mRNA decay-promoting activity of BRF1 is regulated by mitogen-activated protein kinase-activated protein kinase 2

    OpenAIRE

    Maitra, Sushmit; Chou, Chu-Fang; Luber, Christian A.; Lee, Kyung-Yeol; Mann, Matthias; Chen, Ching-Yi

    2008-01-01

    Regulated mRNA decay is a highly important process for the tight control of gene expression. Inherently unstable mRNAs contain AU-rich elements (AREs) in the 3′ untranslated regions that direct rapid mRNA decay by interaction with decay-promoting ARE-binding proteins (ARE-BPs). The decay of ARE-containing mRNAs is regulated by signaling pathways that are believed to directly target ARE-BPs. Here, we show that BRF1 involved in ARE-mediated mRNA decay (AMD) is phosphorylated by MAPK-activated p...

  1. Neutronic characterization and decay heat calculations in the in-vessel fuel storage facilities for MYRRHA/FASTEF

    International Nuclear Information System (INIS)

    Highlights: ► Monte Carlo design of reactor facilities. ► Neutron coupling assessment between critical core and fresh fuel in the storage vessels. ► Power contribution by induced fission from neutrons leaving the core, spontaneous fission and (α, n) sources. ► Power decay heat estimation for different reactor fuel cycles scenarios. ► Material damage assessment in the storage vessels. - Abstract: The main objective of the Central Design Team (CDT) project is to establish an engineering design of a Fast Spectrum Transmutation Experimental Facility (FASTEF) that is the pilot plant of an experimental-scale of both an Accelerator Driven System (ADS) and a Lead Fast Reactor (LFR), based on the MYRRHA reactor concept, planned to be built during the next decade. The MYRRHA reactor concept is devoted to be a multi-purpose irradiation facility aimed at demonstrating the efficient transmutation of long-lived and high radiotoxicity minor actinides, fission products and the associated technology. An important issue regarding the reactor design of the MYRRHA/FASTEF experiment is the In-Vessel Fuel Storage Facilities (IVFSFs), both for fresh and spent fuel, as it might have an impact on the criticality of the overall system that must be quantified. In this work, the neutronic analysis of the in-vessel fuel storage facility and its coupling with the critical core was performed, using the state of the art Monte Carlo program MCNPX 2.6.0 and ORIGEN 2.2 computer code system for calculating the buildup and decay heat of spent fuel. Several parameters were analyzed, like the criticality behavior (namely the Keff), the neutron fluxes and their variations, the fission power production and the radiation damage (the displacements per atom). Finally, also the heat power generated by the fission products decay in the spent fuel was assessed.

  2. Development of margin assessment methodology of decay heat removal function against external hazards. (1) Project overview and snow PRA methodology

    International Nuclear Information System (INIS)

    This paper describes mainly snow probabilistic risk assessment (PRA) methodology development in addition to the project overview. This project addresses extreme weathers (snow, tornado, wind and rainfall), volcanic phenomena and forest fire as representative external hazards. In this project, the methodologies of both PRA and margin assessment are developed for each external hazard through external hazard and accident sequence evaluations mainly in terms of decay heat removal function of a sodium-cooled fast reactor (SFR). Using recent 50 year weather data at a typical Japanese SFR site, snow hazard categories were set the combination of daily snowfall depth (snowfall speed) and snowfall duration which can be calculated by dividing the snow depth by the snowfall speed. For each snow hazard category, the accident sequence was evaluated by producing event trees which consist of several headings representing the loss of decay heat removal. Snow removal action and manual operation of the air cooler dampers were introduced into the event tree as accident managements. In this paper, the snow PRA showed less than 10-6/reactor-year of core damage frequency. The dominant snow hazard category was the combination of 1−2 m/day of snowfall speed and 0.5−0.75 day of snowfall duration. Importance and sensitivity analyses indicated a high risk contribution to secure the access routes. (author)

  3. Development and testing of heat transport fluids for use in active solar heating and cooling systems

    Science.gov (United States)

    Parker, J. C.

    1981-01-01

    Work on heat transport fluids for use with active solar heating and cooling systems is described. Program objectives and how they were accomplished including problems encountered during testing are discussed.

  4. Uncertainty evaluation of reliability of safety grade decay heat removal system of Indian prototype fast breeder reactor

    International Nuclear Information System (INIS)

    Highlights: • Uncertainty analysis of failure frequency of SGDHRS of a medium sized fast reactor is studied. • Lognormal distribution of failure rate of components is taken with error factor of 3. • The error factor in the distribution of failure frequency in most cases is 3. • The relative importance of the safety components is brought out. - Abstract: Deterministic and probabilistic safety assessment of nuclear power reactor technology is very important in assuring that the design is robust and safety systems perform as per requirement. The parameters required as input data for such analysis have uncertainties associated with them. Their impact is to be assessed on the results obtained for such analyses and it affects the overall decision making process. Safety Grade Decay Heat Removal System (SGDHRS) is one of the safety systems in fast breeder reactors and itremoves decay heat after reactor shutdown. It is a critical safety system; hence failure frequency for SGDHR is targeted to be less than 1.0 × 10−7 per reactor year. By bringing diversity in some of the components of SGDHRS, such as sodium-to-sodium decay heat exchanger (DHX), sodium to air heat exchanger (AHX) and valves, one can achieve the targeted low failure frequency of SGDHRS. We perform uncertainty analysis of the reliability of such SGDHRS here. Uncertainty in failure rate (of components of SGDHRS) is assumed to follow the log-normal distribution with error factor of three. Monte Carlo method of sampling is used in MATLAB environment. Results are obtained in terms of mean, median and standard deviation values of failure frequency. Percentile and confidence interval analysis of mean values are also obtained. These provide 95 and 98 percentile and confidence interval values of 98%, 99% and 99.8%. It is found that error factor of failure frequency of SGDHRS is found to be less than 3 in all the cases except the one in which DHX, AHX and Valves are designed with diversity in design. It is to

  5. Reduced-scale water test of natural circulation for decay heat removal in loop-type sodium-cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, T., E-mail: murakami@criepi.denken.or.jp [Central Research Institute of Electric Power Industry, 1646 Abiko, Chiba (Japan); Eguchi, Y., E-mail: eguchi@criepi.denken.or.jp [Central Research Institute of Electric Power Industry, 1646 Abiko, Chiba (Japan); Oyama, K., E-mail: kazuhiro_oyama@mfbr.mhi.co.jp [Mitsubishi FBR Systems, Inc., 2-34-17 Jinguumae, Shibuya, Tokyo (Japan); Watanabe, O., E-mail: osamu4_watanabe@mfbr.mhi.co.jp [Mitsubishi FBR Systems, Inc., 2-34-17 Jinguumae, Shibuya, Tokyo (Japan)

    2015-07-15

    Highlights: • The natural circulation characteristics of a loop-type SFR are examined by a water test. • The performance of decay heat removal system is evaluated using a similarity law. • The effects of flow deviation in the parallel piping of a primary loop are clarified. • The reproducibility of the natural circulation test is confirmed. - Abstract: Water tests of a loop-type sodium-cooled fast reactor have been conducted to physically evaluate the natural circulation characteristics. The water test apparatus was manufactured as a 1/10-scale mock-up of the Japan Sodium-Cooled Fast Reactor, which adopts a decay heat removal system (DHRS) utilizing natural circulation. Tests simulating a variety of events and operation conditions clarified the thermal hydraulic characteristics and core-cooling performance of the natural circulation in the primary loop. Operation conditions such as the duration of the pump flow coast-down and the activation time of the DHRS affect the natural circulation characteristics. A long pump flow coast-down cools the upper plenum of the reactor vessel (RV). This causes the loss of the buoyant force in the RV. The test result indicates that a long pump flow coast-down tends to result in a rapid increase in the core temperature because of the loss of the buoyant force. The delayed activation of the DHRS causes a decrease in the natural circulation flow rate and a temperature rise in the RV. Flow rate deviation and a reverse flow appear in the parallel cold-leg piping in some events, which cause thermal stratification in the cold-leg piping. The DHRS prevents the core temperature from fatally rise even for the most severe design-basis event, in which sodium leakage in a secondary loop of the DHRS and the opening failure of a single damper of the air cooler occur simultaneously. In the water test for the case of siphon break in the primary loop, which is one of the design extension conditions, a circulation flow consisting of ascendant

  6. Characterization and antioxidant activity of essential oils from fresh and decaying leaves of Eucalyptus tereticornis.

    Science.gov (United States)

    Singh, Harminder P; Mittal, Sunil; Kaur, Shalinder; Batish, Daizy R; Kohli, Ravinder K

    2009-08-12

    The composition of essential oils hydrodistilled from fresh and decaying leaves of Eucalyptus tereticornis was analyzed by means of gas chromatography and mass spectrometry, and a total of 68 constituents were identified. The essential oils were assayed for antioxidant activity in terms of scavenging of 2,2-diphenyl-1-picrylhydrazil (DPPH) and hydroxyl (OH(*)) radical, and superoxide anion (O2(-*)).The major constituents of the fresh leaf oil were alpha-pinene (28.53%) and 1,8-cineole (19.48%), whereas in the decaying leaf oil, beta-citronellal (14.15%), (-)-isopulegol (13.35%), and (+)-beta-citronellol (10.73%) were the major components. Both essential oils exhibited a strong radical scavenging activity against DPPH radical with IC50 values of 110 and 139.8 microg/mL for fresh and decaying leaf oil, respectively (IC50 of BHT = 164.2 microg/mL). Further, the essential oils (at 400 microg/mL) also exhibited OH(*) (56-62%) and O2(-*) (65-69%) scavenging activity parallel to the commercial antioxidant BHT/ascorbic acid. However, unlike the essential oils, the major monoterpene constituents exhibited significantly less scavenging activity (<35% DPPH or OH(*); at 400 microg/mL). The study concluded that fresh and decaying leaves of E. tereticornis are a source of monoterpenoid rich oil exhibiting antioxidant activity. PMID:19722579

  7. Conceptual study of ferromagnetic pebbles for heat exhaust in fusion reactors with short power decay length

    Directory of Open Access Journals (Sweden)

    N. Gierse

    2015-03-01

    The key results of this study are that very high heat fluxes are accessible in the operation space of ferromagnetic pebbles, that ferromagnetic pebbles are compatible with tokamak operation and current divertor designs, that the heat removal capability of ferromagnetic pebbles increases as λq decreases and, finally, that for fusion relevant values of q∥ pebble diameters below 100 μm are required.

  8. Effect of UV treatment on antioxidant capacity, antioxidant enzyme activity and decay in strawberry fruit

    Science.gov (United States)

    The changes in antioxidant capacity, enzyme activity and decay inhibition in strawberry fruit (Fragaria x ananassa) illuminated with different UV-C dosages were investigated. Three UV-C illumination durations and dosages, 1 min, 5 min and 10 min, (0.43, 2.15 and 4.30 kJ m-2) tested promoted the anti...

  9. Comparative investigations on wood decay and cellulolytic and xylanolytic activity of some basidiomycete fungi

    Energy Technology Data Exchange (ETDEWEB)

    Hegarty, B.; Steinfurth, A.; Liese, W.; Schmidt, O.

    1987-10-01

    To evaluate physiological differences between various wood-decay fungi and especially different strains per species, comparative investigations were performed with 13 brown-rot and 6 white-rot fungi with respect to their wood decay as well as cellulolytic and xylanolytic capacities. Pine wood samples were considerably decayed by the brown-rot fungi with the two Poria placenta strains showing highest and the two Serpula himantioides isolates lowest mass losses. Most white-rot fungi degraded beech wood samples stronger than pine. Schizophyllum commune was inactive on both substrates. Whereas cellulolytic activity measurement using the clearing of Walseth cellulose gave negative results for some brownrotters, all white-rotters, especially Merulius tremellosus produced cellulase. The decay of Remazol Brilliant Blue stained Avicel in liquid medium proved to be an unsuitable test method for most Serpula lacrymans strains, one P. placenta isolate and for Coriolus versicolor and M. tremellosus. The new method of quantitative photometrical determination of dye release from stained cellulose in agar provided a suitable cellulase assay for most fungi, although the whiterotters C. versicolor, Heterobasidion annosum and M. tremellosus could metabolise the stain. In shake culture, carboxymethylcellulase was not produced by S. lacrymans, P. placenta, Laetiporus sulphureus of Gloeophyllum abietinum, whereas all fungi were xylanolytic. There was only a slight relation between wood decay and enzymatic capacity and, altogether, a great physiological diversity within the fungi was evident.

  10. Activated barrier crossing dynamics in the non-radiative decay of NADH and NADPH

    Energy Technology Data Exchange (ETDEWEB)

    Blacker, Thomas S., E-mail: t.blacker@ucl.ac.uk [Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College London, London WC1E 6BT (United Kingdom); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Research Department of Cell and Developmental Biology, University College London, London WC1E 6BT (United Kingdom); Marsh, Richard J., E-mail: richard.marsh@ucl.ac.uk [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Duchen, Michael R., E-mail: m.duchen@ucl.ac.uk [Research Department of Cell and Developmental Biology, University College London, London WC1E 6BT (United Kingdom); Bain, Angus J., E-mail: a.bain@ucl.ac.uk [Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College London, London WC1E 6BT (United Kingdom); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

    2013-08-30

    Highlights: ► NADH and NADPH have a high rate of non-radiative excited state decay. ► Conformational relaxation is shown to be a significant non-radiative pathway. ► The Kramers equation describes the barrier crossing dynamics of the relaxation. ► Conformational restriction upon enzyme binding will alter NAD(P)H lifetimes. - Abstract: In live tissue, alterations in metabolism induce changes in the fluorescence decay of the biological coenzyme NAD(P)H, the mechanism of which is not well understood. In this work, the fluorescence and anisotropy decay dynamics of NADH and NADPH were investigated as a function of viscosity in a range of water–glycerol solutions. The viscosity dependence of the non-radiative decay is well described by Kramers and Kramers–Hubbard models of activated barrier crossing over a wide viscosity range. Our combined lifetime and anisotropy analysis indicates common mechanisms of non-radiative relaxation in the two emitting states (conformations) of both molecules. The low frequencies associated with barrier crossing suggest that non-radiative decay is mediated by small scale motion (e.g. puckering) of the nicotinamide ring. Variations in the fluorescence lifetimes of NADH and NADPH when bound to different enzymes may therefore be attributed to differing levels of conformational restriction upon binding.

  11. Actinide, Activation Product and Fission Product Decay Data for Reactor-based Applications

    International Nuclear Information System (INIS)

    The UK Activation Product Decay Data Library was first released in September 1977 as UK-PADD1, to be followed by regular improvements on an almost yearly basis up to the assembly of UKPADD6.12 in March 2013. Similarly, the UK Heavy Element and Actinide Decay Data Library followed in December 1981 as UKHEDD1, with the implementation of various modifications leading to UKHEDD2.6, February 2008. Both the data content and evaluation procedures are defined, and the most recent evaluations are described in terms of specific radionuclides and the resulting consistency of their recommended decay-data files. New versions of the UKPADD and UKHEDD libraries are regularly submitted to the NEA Data Bank for possible inclusion in the JEFF library

  12. Decay of Activity Complexes, Formation of Unipolar Magnetic Regions and Coronal Holes in their Causal Relation

    CERN Document Server

    Golubeva, Elena

    2016-01-01

    North-south asymmetry of sunspot activity resulted in an asynchronous reversal of the Sun's polar fields in the current cycle. The asymmetry is also observed in the formation of polar coronal holes. A stable coronal hole was first formed at the South Pole, despite the later polar-field reversal there. The aim of this study is to understand processes making this situation possible. Synoptic magnetic maps from the Global Oscillation Network Group and corresponding coronal-hole maps from the Extreme ultraviolet Imaging Telescope aboard the Solar and Heliospheric Observatory and the Atmospheric Imaging Assembly aboard the Solar Dynamics Observatory are analyzed here to study a causal relationship between the decay of activity complexes, evolution of large-scale magnetic fields, and formation of coronal holes. Ensembles of coronal holes associated with decaying active regions and activity complexes are presented. These ensembles take part in global rearrangements of the Sun's open magnetic flux. In particular, the...

  13. Implementación del modelo de decay heat ANSI/ ANS-5.1-2005 EN TRAC-BF1

    OpenAIRE

    SOLER MARTÍNEZ, MARÍA DESAMPARADOS; Barrachina Celda, Teresa María; Miró Herrero, Rafael; Concejal, A.; Melara, J.; Verdú Martín, Gumersindo Jesús

    2012-01-01

    En este artículo se muestran los resultados de la implementación del modelo de calor residual (Decay Heat) ANSI/ANS-5.1 2005 en el código termohidráulico TRAC-BF1. Los modelos para el cálculo del calor residual en el código TRAC-BF1 se corresponden con el estándar ANS 1973, por defecto, y con el estándar ANS 1979, si es seleccionado por parte del usuario. Con la entrada en vigor del estándar ANS 1994 y, su posterior revisión, el estándar ANS 2005 los modelos que presenta TRAC-...

  14. Comparison of deterministic and stochastic approaches for isotopic concentration and decay heat uncertainty quantification on elementary fission pulse

    Directory of Open Access Journals (Sweden)

    Lahaye S.

    2016-01-01

    Full Text Available Uncertainty quantification of interest outputs in nuclear fuel cycle is an important issue for nuclear safety, from nuclear facilities to long term deposits. Most of those outputs are functions of the isotopic vector density which is estimated by fuel cycle codes, such as DARWIN/PEPIN2, MENDEL, ORIGEN or FISPACT. CEA code systems DARWIN/PEPIN2 and MENDEL propagate by two different methods the uncertainty from nuclear data inputs to isotopic concentrations and decay heat. This paper shows comparisons between those two codes on a Uranium-235 thermal fission pulse. Effects of nuclear data evaluation’s choice (ENDF/B-VII.1, JEFF-3.1.1 and JENDL-2011 is inspected in this paper. All results show good agreement between both codes and methods, ensuring the reliability of both approaches for a given evaluation.

  15. Comparison of deterministic and stochastic approaches for isotopic concentration and decay heat uncertainty quantification on elementary fission pulse

    Science.gov (United States)

    Lahaye, S.; Huynh, T. D.; Tsilanizara, A.

    2016-03-01

    Uncertainty quantification of interest outputs in nuclear fuel cycle is an important issue for nuclear safety, from nuclear facilities to long term deposits. Most of those outputs are functions of the isotopic vector density which is estimated by fuel cycle codes, such as DARWIN/PEPIN2, MENDEL, ORIGEN or FISPACT. CEA code systems DARWIN/PEPIN2 and MENDEL propagate by two different methods the uncertainty from nuclear data inputs to isotopic concentrations and decay heat. This paper shows comparisons between those two codes on a Uranium-235 thermal fission pulse. Effects of nuclear data evaluation's choice (ENDF/B-VII.1, JEFF-3.1.1 and JENDL-2011) is inspected in this paper. All results show good agreement between both codes and methods, ensuring the reliability of both approaches for a given evaluation.

  16. 多样化非能动衰变热排出方法研究%Study on diverse passive decay heat removal approach

    Institute of Scientific and Technical Information of China (English)

    林千; 司胜义

    2012-01-01

    One of the most important principles for nuclear safety is the decay heat removal in accidents. Passive decay heat removal systems are extremely helpful to enhance the safety. In currently design of many advanced nuclear reactors, kinds of passive systems are proposed or developed, such as the passive residual heat removal system, passive injection system, passive containment cooling system. These systems provide entire passive heat removal paths from core to ultimate heat sink. Various kinds of passive systems for decay heat removal are summarized; their common features or differences on heat removal paths and design principle are analyzed. It is found that, these passive decay heat removal paths are similarly common on and connected by several basic heat transfer modes and steps. By the combinations or connections of basic modes and steps, new passive decay heat removal approach or diverse system can be proposed.%事故情况下的衰变热排出是涉及核安全的重要方面.采用非能动方法来排出衰变热对于提高核反应堆的安全性非常有益.在目前一些先进反应堆中通过设置非能动余热排出系统、非能动安注系统、非能动安全壳冷却系统等安全子系统,形成多样化的从堆芯到最终热阱的非能动衰变热排出渠道.论文对多种非能动衰变热排出方法和系统设计方案进行了归纳总结,比较分析了这些非能动衰变热排出方法的共性特征和区别,探讨了非能动衰变热排出系统的设计原理.通过对传热过程分解,将这些衰变热排出方法表达为一些基本传热形式的不同组合方式,根据不同的组合可获得多样化的非能动衰变热排出方法和新的系统设计方案.

  17. Periphytic photosynthetic stimulation of extracellular enzyme activity in aquatic microbial communities associated with decaying typha litter.

    Science.gov (United States)

    Francoeur, Steven N; Schaecher, Mark; Neely, Robert K; Kuehn, Kevin A

    2006-11-01

    We examined the effect of light on extracellular enzyme activities of periphytic/endogenous microbial assemblages associated with decomposing litter of an emergent macrophyte Typha angustifolia within a small inland wetland in southeastern Michigan. Standing-dead Typha leaf litter was collected, placed into floating wire mesh litter baskets, and submerged in a wetland pool. Enzyme saturation assays were conducted on three occasions following litter submergence (days 9, 28, and 44) to generate saturation curves for the individual enzymes tested and to examine potential differences in enzyme saturation kinetics during microbial colonization and development. Experimental light manipulations were conducted on two occasions during microbial development (days 10 and 29). Short-term (30 min) light exposure significantly increased extracellular beta-glucosidase activity of litter-associated microbial communities. Activities of beta-xylosidase and leucine-aminopeptidase were not stimulated, and stimulation of phosphatase activity was variable. The exact mechanism for increased enzyme activity remains unknown, but it may have been increased pH arising from periphytic algal photosynthesis. These results suggest that extracellular enzyme activity in microbial communities colonizing natural organic substrata may be influenced by light/photosynthesis, as has previously been demonstrated for periphyton communities grown on artificial, inert substrata. Thus, light/photosynthetic mediated stimulation of extracellular enzyme activities may be a common occurrence in microbial communities associated with natural decaying plant litter in wetlands and might engender diurnal patterns in other microbial decay processes (e.g., production, organic matter decomposition, and mineralization). PMID:17082997

  18. Solar neutrinos, solar flares, solar activity cycle and the proton decay

    Science.gov (United States)

    Raychaudhuri, P.

    1985-01-01

    It is shown that there may be a correlation between the galactic cosmic rays and the solar neutrino data, but it appears that the neutrino flux which may be generated during the large solar cosmic ray events cannot in any way effect the solar neutrino data in Davis experiment. Only initial stage of mixing between the solar core and solar outer layers after the sunspot maximum in the solar activity cycle can explain the higher (run number 27 and 71) of solar neutrino data in Davis experiment. But solar flare induced atmospheric neutrino flux may have effect in the nucleon decay detector on the underground. The neutrino flux from solar cosmic rays may be a useful guide to understand the background of nucleon decay, magnetic monopole search, and the detection of neutrino flux in sea water experiment.

  19. Active heat exchange system development for latent heat thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Lefrois, R.T.; Knowles, G.R.; Mathur, A.K.; Budimir, J.

    1979-02-01

    The report describes active heat exchange concepts for use with thermal energy storage systems in the temperature range of 250/sup 0/C to 350/sup 0/C, using the heat of fusion of molten salts for storing thermal energy. It identifies over 25 novel techniques for active heat exchange thermal energy storage systems. Salt mixtures that freeze and melt in appropriate ranges are identified and are evaluated for physico-chemical, economic, corrosive and safety characteristics. Eight active heat exchange concepts for heat transfer during solidification are conceived and conceptually designed for use with selected storage media. The concepts are analyzed for their scalability, maintenance, safety, technological development and costs. A model for estimating and scaling storage system costs is developed and is used for economic evaluation of salt mixtures and heat exchange concepts for a large scale application. The importance of comparing salts and heat exchange concepts on a total system cost basis, rather than the component cost basis alone, is pointed out. Comparison of these costs with current state-of-the-art systems should be avoided due to significant differences in developmental status. The heat exchange concepts were sized and compared for 6.5 MPa/281/sup 0/C steam conditions and a 1000 MW(t) heat rate for six hours. A cost sensitivity analysis for other design conditions is also carried out. The study resulted in the selection of a shell and coated-tube heat exchanger concept and a direct contact-reflux boiler heat exchange concept. For the storage medium, a dilute eutectic mixture of 99 wt % NaNO/sub 3/ and 1 wt % NaOH is selected for use in experimenting with the selected heat exchanger concepts in subsequent tasks.

  20. Heat dissipation guides activation in signaling proteins

    OpenAIRE

    Weber, Jeffrey K.; Shukla, Diwakar; Pande, Vijay S.

    2015-01-01

    As with their macroscopic counterparts, the moving parts of nanoscale protein machines grow hot while in operation. A portion of the energy biomolecules harness to perform meaningful work is always dissipated as heat into the surroundings. Here, we feature a methodology by which dominant dissipative trajectories can be extracted from detailed models of protein dynamics. In two important classes of signaling proteins [kinases and G-protein–coupled receptors (GPCRs)], we find that the regions o...

  1. Simulation of decay heat removal by natural convection in a pool type fast reactor model-ramona-with coupled 1D/2D thermal hydraulic code system

    Energy Technology Data Exchange (ETDEWEB)

    Kasinathan, N.; Rajakumar, A.; Vaidyanathan, G.; Chetal, S.C. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    1995-09-01

    Post shutdown decay heat removal is an important safety requirement in any nuclear system. In order to improve the reliability of this function, Liquid metal (sodium) cooled fast breeder reactors (LMFBR) are equipped with redundant hot pool dipped immersion coolers connected to natural draught air cooled heat exchangers through intermediate sodium circuits. During decay heat removal, flow through the core, immersion cooler primary side and in the intermediate sodium circuits are also through natural convection. In order to establish the viability and validate computer codes used in making predictions, a 1:20 scale experimental model called RAMONA with water as coolant has been built and experimental simulation of decay heat removal situation has been performed at KfK Karlsruhe. Results of two such experiments have been compiled and published as benchmarks. This paper brings out the results of the numerical simulation of one of the benchmark case through a 1D/2D coupled code system, DHDYN-1D/THYC-2D and the salient features of the comparisons. Brief description of the formulations of the codes are also included.

  2. Numerical Simulations of Active Region Scale Flux Emergence: From Spot Formation to Decay

    Science.gov (United States)

    Rempel, M.; Cheung, M. C. M.

    2014-04-01

    We present numerical simulations of active region scale flux emergence covering a time span of up to 6 days. Flux emergence is driven by a bottom boundary condition that advects a semi-torus of magnetic field with 1.7 × 1022 Mx flux into the computational domain. The simulations show that, even in the absence of twist, the magnetic flux is able the rise through the upper 15.5 Mm of the convection zone and emerge into the photosphere to form spots. We find that spot formation is sensitive to the persistence of upflows at the bottom boundary footpoints, i.e., a continuing upflow would prevent spot formation. In addition, the presence of a torus-aligned flow (such flow into the retrograde direction is expected from angular momentum conservation during the rise of flux ropes through the convection zone) leads to a significant asymmetry between the pair of spots, with the spot corresponding to the leading spot on the Sun being more axisymmetric and coherent, but also forming with a delay relative to the following spot. The spot formation phase transitions directly into a decay phase. Subsurface flows fragment the magnetic field and lead to intrusions of almost field free plasma underneath the photosphere. When such intrusions reach photospheric layers, the spot fragments. The timescale for spot decay is comparable to the longest convective timescales present in the simulation domain. We find that the dispersal of flux from a simulated spot in the first two days of the decay phase is consistent with self-similar decay by turbulent diffusion.

  3. Heat of Hydration of Low Activity Cementitious Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Nasol, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-07-23

    During the curing of secondary waste grout, the hydraulic materials in the dry mix react exothermally with the water in the secondary low-activity waste (LAW). The heat released, called the heat of hydration, can be measured using a TAM Air Isothermal Calorimeter. By holding temperature constant in the instrument, the heat of hydration during the curing process can be determined. This will provide information that can be used in the design of a waste solidification facility. At the Savannah River National Laboratory (SRNL), the heat of hydration and other physical properties are being collected on grout prepared using three simulants of liquid secondary waste generated at the Hanford Site. From this study it was found that both the simulant and dry mix each had an effect on the heat of hydration. It was also concluded that the higher the cement content in the dry materials mix, the greater the heat of hydration during the curing of grout.

  4. Active latent heat storage with a screw heat exchanger - experimental results for heat transfer and concept for high pressure steam

    Science.gov (United States)

    Zipf, Verena; Willert, Daniel; Neuhäuser, Anton

    2016-05-01

    An innovative active latent heat storage concept was invented and developed at Fraunhofer ISE. It uses a screw heat exchanger (SHE) for the phase change during the transport of a phase change material (PCM) from a cold to a hot tank or vice versa. This separates heat transfer and storage tank in comparison to existing concepts. A test rig has been built in order to investigate the heat transfer coefficients of the SHE during melting and crystallization of the PCM. The knowledge of these characteristics is crucial in order to assess the performance of the latent heat storage in a thermal system. The test rig contains a double shafted SHE, which is heated or cooled with thermal oil. The overall heat transfer coefficient U and the convective heat transfer coefficient on the PCM side hPCM both for charging and discharging have been calculated based on the measured data. For charging, the overall heat transfer coefficient in the tested SHE was Uch = 308 W/m2K and for discharging Udis = 210 W/m2K. Based on the values for hPCM the overall heat transfer coefficients for a larger SHE with steam as heat transfer fluid and an optimized geometry were calculated with Uch = 320 W/m2K for charging and Udis = 243 W/m2K for discharging. For pressures as high as p = 100 bar, an SHE concept has been developed, which uses an organic fluid inside the flight of the SHE as working media. With this concept, the SHE can also be deployed for very high pressure, e.g. as storage in solar thermal power plants.

  5. Active heat exchange system development for latent heat thermal energy storage

    Science.gov (United States)

    Lefrois, R. T.; Knowles, G. R.; Mathur, A. K.; Budimir, J.

    1979-01-01

    Active heat exchange concepts for use with thermal energy storage systems in the temperature range of 250 C to 350 C, using the heat of fusion of molten salts for storing thermal energy are described. Salt mixtures that freeze and melt in appropriate ranges are identified and are evaluated for physico-chemical, economic, corrosive and safety characteristics. Eight active heat exchange concepts for heat transfer during solidification are conceived and conceptually designed for use with selected storage media. The concepts are analyzed for their scalability, maintenance, safety, technological development and costs. A model for estimating and scaling storage system costs is developed and is used for economic evaluation of salt mixtures and heat exchange concepts for a large scale application. The importance of comparing salts and heat exchange concepts on a total system cost basis, rather than the component cost basis alone, is pointed out. The heat exchange concepts were sized and compared for 6.5 MPa/281 C steam conditions and a 1000 MW(t) heat rate for six hours. A cost sensitivity analysis for other design conditions is also carried out.

  6. Activity size distributions for long-lived radon decay products in aerosols collected in Barcelona (Spain)

    International Nuclear Information System (INIS)

    The activity median aerodynamic diameters (AMADs) of long-lived radon decay product (210Pb, 210Po) in aerosols collected in the Barcelona area (Northeast Spain) during the period from April 2006 to February 2008 are presented. The 210Po mean AMAD was 420 nm, while the 210Pb mean AMAD was 500 nm. The temporal evolution of 210Pb and 210Po AMADs shows maxima in autumn and winter and minima in spring and summer. 210Pb AMAD are being used to estimate the mean-residence time of atmospheric aerosols.

  7. Significant Isotopes Selection of Core Inventory Based on Decay Heat%基于衰变热的堆芯重要核素选取

    Institute of Scientific and Technical Information of China (English)

    李亢; 于悦海; 陈志宏

    2014-01-01

    衰变热在反应堆设计及安全分析中至关重要,目前计算衰变热主要基于行业标准和专用程序两种方法。通过对PWR燃料组件分别采用两种方法进行计算分析,相互验证了结果。详细分析了停堆不同时刻多种核素对衰变热的贡献,筛选出主要贡献者,为堆芯源项核素的选择提供参考。结果显示约50个核素即可包络停堆后100 h~50 a内95%以上的衰变热贡献。并对标准与程序结果的差异进行了分析,提出了标准适用范围的建议。%Decay heat is extremely important in core design and safety analysis .At pres-ent decay heat calculations are usually based on industrial standards or professional computer codes . Using the two methods to calculate the PWR assembly irradiation respectively ,the validation was done by comparing the results with the two methods and the results were reasonably close .The analytical work was carried out on specific contri-butions made by important isotopes to decay heat at different shutdow n time and the main contributors were screened out as a reference for the core source term inventory selection .The result shows that about 50 isotopes can bound 95% decay heat during 100 h-50 a after shutdown .Discrepancies between the standard and computer code were also investigated .Some instructive advices on suitable region were given for applying the standard .

  8. Design of an experiment to measure the decay heat of an irradiated PWR fuel: MERCI experiment; Conception d'une experience de mesure de la puissance residuelle d'un combustible irradie: l'experience MERCI

    Energy Technology Data Exchange (ETDEWEB)

    Bourganel, St

    2002-11-01

    After a reactor shutdown, a significant quantity of energy known as 'decay heat' continues to be generated from the irradiated fuel. This heat source is due to the disintegration energy of fission products and actinides. Decay heat determination of an irradiated fuel is of the utmost importance for safety analysis as the design cooling systems, spent fuel transport, or handling. Furthermore, the uncertainty on decay heat has a straight economic impact. The unloading fuel spent time is an example. The purpose of MERCI experiment (irradiated fuel decay heat measurement) consists in qualifying computer codes, particularly the DARWIN code system developed by the CEA in relation to industrial organizations, as EDF, FRAMATOME and COGEMA. To achieve this goal, a UOX fuel is irradiated in the vicinity of the OSIRIS research reactor, and then the decay heat is measured by using a calorimeter. The objective is to reduce the decay heat uncertainties from 8% to 3 or 4% at short cooling times. A full simulation on computer of the MERCI experiment has been achieved: fuel irradiation analysis is performed using transport code TRIPOLI4 and evolution code DARWIN/PEPIN2, and heat transfer with CASTEM2000 code. The results obtained are used for the design of this experiment. Moreover, we propose a calibration procedure decreasing the influence of uncertainty measurements and an interpretation method of the experimental results and evaluation of associated uncertainties. (author)

  9. Analysis of Heat Transfer in Actively Cooled Compound Gun Barrel

    Institute of Scientific and Technical Information of China (English)

    WU Bin; XIA Wei

    2005-01-01

    when a gun fires, a large amount of heat is brought in the barrel. Erosion/wear and security problems(self ignition of the propellant) associated with this high thermal energy have to be solved owing to the use of higher combustion gas temperature for improved cannon performance and firing at the sustained high rates. Barrel cooling technologies are the effective measures for addressing this issue. In view of the importance of having knowledge of the heat flux, an approach to calculate heat flux based on measurements was presented and validated. The calculated heat flux is used as the inner boundary condition for modeling heat transfer in a 155 mm mid-wall cooled compound gun barrel. Theoretical analysis and simulated results show that natural air cooling is dramatically slower than the forced liquid mid-wall cooling, accordingly wear life of actively cooled barrel is increased and barrel overheating is prevented.

  10. Active heat exchange system development for latent heat thermal energy storage

    Science.gov (United States)

    Lefrois, R. T.; Mathur, A. K.

    1980-04-01

    Five tasks to select, design, fabricate, test and evaluate candidate active heat exchanger modules for future applications to solar and conventional utility power plants were discussed. Alternative mechanizations of active heat exchange concepts were analyzed for use with heat of fusion phase change materials (PCMs) in the temperature range of 250 to 350 C. Twenty-six heat exchange concepts were reviewed, and eight were selected for detailed assessment. Two candidates were selected for small-scale experimentation: a coated tube and shell heat exchanger and a direct contact reflux boiler. A dilute eutectic mixture of sodium nitrate and sodium hydroxide was selected as the PCM from over 50 candidate inorganic salt mixtures. Based on a salt screening process, eight major component salts were selected initially for further evaluation. The most attractive major components in the temperature range of 250 to 350 C appeared to be NaNO3, NaNO2, and NaOH. Sketches of the two active heat exchange concepts selected for test are given.

  11. Heating of active region cores: Impulsive or steady?

    Science.gov (United States)

    Tripathi, Durgesh

    The question of active region heating has proven to be highly challenging since its discovery in 1940s. The recent observational facilities have shed new lights towards the understanding of this problem. In this paper we review some of the new measurements to study the heating mechanisms in the hot core loops of active regions using the observations recorded by Solar Ultraviolet Measurements of Emitted Radiation (SUMER) onboard SoHO and the Extreme-ultraviolet Imaging Spectrometer (EIS) aboard Hinode. These new measurements show that the properties of hot core loops are consistent with by impulsive heating -- low frequency nanoflare - scenario. However, the evidences are not strong enough to rule-out steady heating completely. Further measurement using better spectral resolution and temperature coverage is required, which will be provided by Interface Region Imaging Spectrometer (IRIS) and Solar-C in near future.

  12. Stellar activity and coronal heating: an overview of recent results

    Science.gov (United States)

    Testa, Paola; Saar, Steven H.; Drake, Jeremy J.

    2015-01-01

    Observations of the coronae of the Sun and of solar-like stars provide complementary information to advance our understanding of stellar magnetic activity, and of the processes leading to the heating of their outer atmospheres. While solar observations allow us to study the corona at high spatial and temporal resolution, the study of stellar coronae allows us to probe stellar activity over a wide range of ages and stellar parameters. Stellar studies therefore provide us with additional tools for understanding coronal heating processes, as well as the long-term evolution of solar X-ray activity. We discuss how recent studies of stellar magnetic fields and coronae contribute to our understanding of the phenomenon of activity and coronal heating in late-type stars. PMID:25897087

  13. Stellar Activity and Coronal Heating: an overview of recent results

    CERN Document Server

    Testa, Paola; Drake, Jeremy

    2015-01-01

    Observations of the coronae of the Sun and of solar-like stars provide complementary information to advance our understanding of stellar magnetic activity, and of the processes leading to the heating of their outer atmospheres. While solar observations allow us to study the corona at high spatial and temporal resolution, the study of stellar coronae allows us to probe stellar activity over a wide range of ages and stellar parameters. Stellar studies therefore provide us with additional tools for understanding coronal heating processes, as well as the long-term evolution of solar X-ray activity. We discuss how recent studies of stellar magnetic fields and coronae contribute to our understanding of the phenomenon of activity and coronal heating in late-type stars.

  14. Brain activity and fatigue during prolonged exercise in the heat

    DEFF Research Database (Denmark)

    Hyldig, Tino Hoffmann

    2001-01-01

    We hypothesized that fatigue due to hyperthermia during prolonged exercise in the heat is in part related to alterations in frontal cortical brain activity. The electroencephalographic activity (EEG) of the frontal cortex of the brain was measured in seven cyclists [maximal O2 uptake (VO2max) 4...

  15. Experimental research on a CFCs free thermally activated heat pump

    International Nuclear Information System (INIS)

    This paper deals with test results of a new type of Thermally Activated Heat Pump (TAHP) based on the highly efficient Vuilleumier cycle using helium gas as its refrigerant and natural gas as fuel of its external system. These test results show that, in addition to being CFCs free, this heat pump brings about lower CO2 and NOx emissions. (TEC). 7 figs., 6 refs

  16. Comparison of the effect of gamma irradiation, heat-radiation combination, and sulphur dioxide generating pads on decay and quality of grapes

    International Nuclear Information System (INIS)

    Effect of gamma irradiation, heat-radiation combination and in-package sulphur dioxide fumigation on fungal decay, and quality of seedless grape cultivars, Thompson, Sonaka and Tas-A-Ganesh was evaluated under different storage regimes. Irradiation at 2 kGy or a combination of hot water dip (50 degC, 5 min), plus irradiation (1 kGy) showed less spoilage due to Rhizopus spp. and Botrytis spp. in grapes packaged in tissue paper lined boxes and stored at 4 deg, 15 deg and 25 degC. Storage in polyethylene lined boxes increased the fungal rot. In-package sulphur dioxide generating pad was most effective for control of decay in polyethylene lined boxes stored at 10 deg and 20 degC, but caused berry bleaching. Irradiation at 2.5 or 3.5 kGy controlled decay at 10 degC, but not so effectively at 20 degC. Organoleptic quality, berry firmness, and soluble solids were not affected by irradiation, but decreases in titratable acids and ascorbic acid were recorded. Packaging in polyethylene lined boxes retained berry turgidity, while slight shrivelling occurred in tissue paper lined boxes. The results indicate that gamma irradiation has potential as an alternative to sulphur dioxide fumigation for decay control during shipping and storage. (author). 20 refs., 4 tabs

  17. Nuclide Importance to Criticality Safety, Decay Heating, and Source Terms Related to Transport and Interim Storage of High-Burnup LWR Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gauld, I. C.; Ryman, J. C.

    2000-12-11

    This report investigates trends in the radiological decay properties and changes in relative nuclide importance associated with increasing enrichments and burnup for spent LWR fuel as they affect the areas of criticality safety, thermal analysis (decay heat), and shielding analysis of spent fuel transport and storage casks. To facilitate identifying the changes in the spent fuel compositions that most directly impact these application areas, the dominant nuclides in each area have been identified and ranked by importance. The importance is investigated as a function of increasing burnup to assist in identifying the key changes in spent fuel characteristics between conventional- and extended-burnup regimes. Studies involving both pressurized water-reactor (PWR) fuel assemblies and boiling-water-reactor (BWR) assemblies are included. This study is seen to be a necessary first step in identifying the high-burnup spent fuel characteristics that may adversely affect the accuracy of current computational methods and data, assess the potential impact on previous guidance on isotopic source terms and decay-heat values, and thus help identify areas for methods and data improvement. Finally, several recommendations on the direction of possible future code validation efforts for high-burnup spent fuel predictions are presented.

  18. A decaying factor accounts for contained activity in neuronal networks with no need of hierarchical or modular organization

    CERN Document Server

    Amancio, Diego R; Costa, Luciano da F

    2012-01-01

    The mechanisms responsible for contention of activity in systems represented by networks are crucial in various phenomena, as in diseases such as epilepsy that affects the neuronal networks, and for information dissemination in social networks. The first models to account for contained activity included triggering and inhibition processes, but they cannot be applied to social networks where inhibition is clearly absent. A recent model showed that contained activity can be achieved with no need of inhibition processes provided that the network is subdivided in modules (communities). In this paper, we introduce a new concept inspired in the Hebbian theory through which activity contention is reached by incorporating a dynamics based on a decaying activity in a random walk mechanism preferential to the node activity. Upon selecting the decay coefficient within a proper range, we observed sustained activity in all the networks tested, viz. random, Barabasi-Albert and geographical networks. The generality of this ...

  19. Heat and mass flux estimation of modern seafloor hydrothermal activity

    Institute of Scientific and Technical Information of China (English)

    ZHAI Shikui; WANG Xingtao; YU Zenghui

    2006-01-01

    Research on heat and mass flux yielded by modern seafloor hydrothermal activity is very important, because it is involved not only in the base of ocean environment research, but also in the historical evolution of seawater properties. Currently, estimating heat flux is based on the observation data of hydrothermal smokers, low-temperature diffusive flow and mid-ocean ridge mainly. But there are some faults, for example, there is lack of a concurrent conductive item in estimating the heat flux by smokers and the error between the half-space cooling model and the observation data is too large. So, three kinds of methods are applied to re-estimating the heat flux of hydrothermal activity resepectively, corresponding estimation is 97.359 GW by hydrothermal smoker and diffusive flow, 84.895 GW by hydrothermal plume, and 4.11 TW by exponential attenuation method put forward by this paper. Research on mass flux estimation is relatively rare, the main reason for this is insufficient field observation data. Mass fluxes of different elements are calculated using hydrothermal vent fluid data from the TAG hydrothermal area on the Mid-Atlantic Ridge for the first time. Difference of estimations by different methods reflects the researching extent of hydrothermal activity, and systematically in-situ observation will help to estimate the contribution of hydrothermal activity to ocean chemical environment, ocean circulation and global climate precisely.

  20. Conceptual Design of Ultra-long-life Core Fast Reactor (UCFR) with Ga-based Passive Decay Heat Removal System (PDHRS)

    International Nuclear Information System (INIS)

    UCFR (Ultra-long-life Core Fast Reactor) is a 260MWth /100MWe sodium-cooled fast reactor which requires no on-site refueling and meets the need for future nuclear energy systems. UCFR is a pool type reactor with metallic fuels, four intermediate heat exchangers, two steam generators, and passive decay heat removal systems. Because gallium has the chemical reaction safety such as low oxygen reactivity compared to sodium, it can be used as a boundary material between sodium and atmosphere to enhance the nuclear safety of UCFR. In this research, design studied for neutronics and thermal-hydraulics are included. The safety performance of UCFR will be analyzed with MARS-LMR. Although MARS-LMR was originally intended for a safety analysis of liquid metal-cooled reactor, gallium properties were newly added to this code which is applicable for gallium-cooled systems. The properties of various liquid metals are indicated in table II. Considering needs to improve uranium utilization and solve the nuclear proliferation, ultra-long cycle fast reactor has been developed. UCFR is a 260MWth/100MWe sodium-cooled fast reactor which requires no on-site refueling during design period with metallic fuels (U-5Zr), HT-9 cladding, four intermediate heat exchangers, two steam generators, and Ga-based PDHRS. Through this paper, new PDHRS using gallium that can be remove decay heat passively for an infinite time is suggested. In Ga-based PDHRS, the both water and air as an ultimate heat sink will be can be considered because gallium has the chemical reaction safety. In this research, design study for neutronics and thermal-hydraulics were also included. For safety analysis of UCFR using MARS-LMR, detailed design of UCFR with Ga-based PDHRS will be required

  1. Calculations of criticality, nuclide compositions, decay heat and sources for WWER-440 fuel by new version of the SCALE 5 code

    International Nuclear Information System (INIS)

    In this article are compared theoretical results by new version of the SCALE5 code with experiments or other theoretical calculation for: 1. criticality: -measurement on ZR-6 and LR-0; - numerical benchmark No. 1.3 and 4 (CB1, CB3, CB4); 2. nuclide compositions: - measurement in Kurchatov institute for 3,6 %; - measurement in JAERI(PWR 17x17); - numerical benchmark No. 2-Source (CB2); 3. sources and decay heat:- numerical benchmark No.2-Source (CB2-S); The focus is on modules KENO, TRITON and ORIGEN-S (Authors)

  2. A decaying factor accounts for contained activity in neuronal networks with no need of hierarchical or modular organization

    Science.gov (United States)

    Amancio, Diego R.; Oliveira, Osvaldo N., Jr.; Costa, Luciano da F.

    2012-11-01

    The mechanisms responsible for containing activity in systems represented by networks are crucial in various phenomena, for example, in diseases such as epilepsy that affect the neuronal networks and for information dissemination in social networks. The first models to account for contained activity included triggering and inhibition processes, but they cannot be applied to social networks where inhibition is clearly absent. A recent model showed that contained activity can be achieved with no need of inhibition processes provided that the network is subdivided into modules (communities). In this paper, we introduce a new concept inspired in the Hebbian theory, through which containment of activity is achieved by incorporating a dynamics based on a decaying activity in a random walk mechanism preferential to the node activity. Upon selecting the decay coefficient within a proper range, we observed sustained activity in all the networks tested, namely, random, Barabási-Albert and geographical networks. The generality of this finding was confirmed by showing that modularity is no longer needed if the dynamics based on the integrate-and-fire dynamics incorporated the decay factor. Taken together, these results provide a proof of principle that persistent, restrained network activation might occur in the absence of any particular topological structure. This may be the reason why neuronal activity does not spread out to the entire neuronal network, even when no special topological organization exists. .

  3. A decaying factor accounts for contained activity in neuronal networks with no need of hierarchical or modular organization

    International Nuclear Information System (INIS)

    The mechanisms responsible for containing activity in systems represented by networks are crucial in various phenomena, for example, in diseases such as epilepsy that affect the neuronal networks and for information dissemination in social networks. The first models to account for contained activity included triggering and inhibition processes, but they cannot be applied to social networks where inhibition is clearly absent. A recent model showed that contained activity can be achieved with no need of inhibition processes provided that the network is subdivided into modules (communities). In this paper, we introduce a new concept inspired in the Hebbian theory, through which containment of activity is achieved by incorporating a dynamics based on a decaying activity in a random walk mechanism preferential to the node activity. Upon selecting the decay coefficient within a proper range, we observed sustained activity in all the networks tested, namely, random, Barabási–Albert and geographical networks. The generality of this finding was confirmed by showing that modularity is no longer needed if the dynamics based on the integrate-and-fire dynamics incorporated the decay factor. Taken together, these results provide a proof of principle that persistent, restrained network activation might occur in the absence of any particular topological structure. This may be the reason why neuronal activity does not spread out to the entire neuronal network, even when no special topological organization exists. (paper)

  4. Eruption of the magnetic flux rope in a fast decayed active region

    CERN Document Server

    Yang, Shangbin; Liu, Jihong

    2013-01-01

    An isolated and fast decayed active region (NOAA 9729) was observed when passing through solar disk. There is only one CME related with it that give us a good opportunity to investigate the whole process of the CME. Filament in this active region rises up rapidly and then hesitates and disintegrates into flare loops. The rising filament from EIT images separates into two parts just before eruption. A new filament reforms several hours later after CME and the axis of this new one rotates clockwise about 22 degrees comparing with that of the former one. We also observed a bright transient J-shaped X-ray sigmoid immediately appears after filament eruption. It quickly develops into a soft X-ray cusp and rises up firstly then drops down. Two magnetic cancelation regions have been observed clearly just before filament eruption. Moreover, the magnetic flux rope erupted as the magnetic helicity approach the maximum and the normalized helicity is -0.036 when the magnetic flux rope erupted, which is close to the predic...

  5. Investigating the jet activity accompanying the production at the LHC of a massive scalar particle decaying into photons

    Science.gov (United States)

    Fuks, Benjamin; Kang, Dong Woo; Park, Seong Chan; Seo, Min-Seok

    2016-10-01

    We study the jet activity that accompanies the production by gluon fusion of a new physics scalar particle decaying into photons at the LHC. In the considered scenarios, both the production and decay mechanisms are governed by loop-induced interactions involving a heavy colored state. We show that the presence of large new physics contributions to the inclusive diphoton invariant-mass spectrum always implies a significant production rate of non-standard diphoton events containing extra hard jets. We investigate the existence of possible handles that could provide a way to obtain information on the underlying physics behind the scalar resonance, and this in a wide mass window.

  6. Investigating the jet activity accompanying the production at the LHC of a massive scalar particle decaying into photons

    CERN Document Server

    Fuks, Benjamin; Park, Seong Chan; Seo, Min-Seok

    2016-01-01

    We study the jet activity that accompanies the production by gluon fusion of a new physics scalar particle decaying into photons at the LHC. In the considered scenarios, both the production and decay mechanisms are governed by loop-induced interactions involving a heavy colored state. We show that the presence of large new physics contributions to the inclusive diphoton invariant-mass spectrum always implies a significant production rate of non-standard diphoton events containing extra hard jets. We investigate the existence of possible handles that could provide a way to obtain information on the underlying physics behind the scalar resonance, and this in a wide mass window.

  7. Study on occurrence possibility of dust explosion, hydrogen explosion and decay heat for safety of a process of manufacturing for DUPIC fuel

    Energy Technology Data Exchange (ETDEWEB)

    Park, S. H.; Park, J. J.; Lee, H. H.; Shin, J. M.; Yang, M. S. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-02-01

    DUPIC process is a dry powder processing technology to manufacture CANDU fuel from spent PWR fuel through powder fabrication processes. The DUPIC process consist of the slitting of the spent PWR fuel rods, OREOX processing to produce the powder feedstock, the milling of the produced powder, the granulation of the milled powder, an the mixing of the granulated powder with pressing lubricants, the pelletizing and sintering, and the welding of the fuel rod by laser welding technique. All these processes should be conducted by remote means in a hot-cell environment(M6 hot-cell). Since this process contains powder handling of highly radioactive spent fuel and reduction process with hydrogen, prevention of dust explosion, hydrogen explosion and safe control on decay heat of the fuel is very important. Therefore, this study estimated an occurrence possibility of dust explosion, hydrogen explosion and decay heat for safety of a process of manufacturing for DUPIC fuel. 9 refs., 12 figs., 29 tabs. (Author)

  8. Laser-heating-based active optics for synchrotron radiation applications

    CERN Document Server

    Yang, Fugui; Zhang, Xiaowei

    2016-01-01

    Active optics has attracted considerable interest from researchers in synchrotron radiation facilities, because of its capacity for x-ray wavefront correction. Here, we report a novel and efficient technique for correcting or modulating a mirror surface profile based on laser-heating-induced thermal expansion. An experimental study of the characteristics of the surface thermal deformation response indicates that the power of a milliwatt laser yields a bump height as low as sub-nanometer scale, and that variation of the spot size modulates the response function width effectively. In addition, the capacity of the laser-heating technique for free-form surface modulation is demonstrated via a surface correction experiment. The developed method is a promising new approach towards effective x-ray active optics coupled with at-wavelength metrology techniques.

  9. Using the Inflection Points and Rates of Growth and Decay to Predict Levels of Solar Activity

    Science.gov (United States)

    Wilson, Robert M.; Hathaway, David H.

    2008-01-01

    The ascending and descending inflection points and rates of growth and decay at specific times during the sunspot cycle are examined as predictors for future activity. On average, the ascending inflection point occurs about 1-2 yr after sunspot minimum amplitude (Rm) and the descending inflection point occurs about 6-7 yr after Rm. The ascending inflection point and the inferred slope (including the 12-mo moving average (12-mma) of (Delta)R (the month-to-month change in the smoothed monthly mean sunspot number (R)) at the ascending inflection point provide strong indications as to the expected size of the ongoing cycle s sunspot maximum amplitude (RM), while the descending inflection point appears to provide an indication as to the expected length of the ongoing cycle. The value of the 12-mma of (Delta)R at elapsed time T = 27 mo past the epoch of RM (E(RM)) seems to provide a strong indication as to the expected size of Rm for the following cycle. The expected Rm for cycle 24 is 7.6 +/- 4.4 (the 90-percent prediction interval), occurring before September 2008. Evidence is also presented for secular rises in selected cycle-related parameters and for preferential grouping of sunspot cycles by amplitude and/or period.

  10. THE AIMS AND ACTIVITIES OF THE INTERNATIONAL NETWORK OF NUCLEAR STRUCTURE AND DECAY DATA EVALUATORS.

    Energy Technology Data Exchange (ETDEWEB)

    NICHOLS,A.L.; TULI, J.K.

    2007-04-22

    International Network of Nuclear Structure and Decay Data (NSDD) Evaluators consists of a number of evaluation groups and data service centers in several countries that appreciate the merits of working together to maintain and ensure the quality and comprehensive content of the ENSDF database (Evaluated Nuclear Structure Data File). Biennial meetings of the network are held under the auspices of the International Atomic Energy Agency (IAEA) to assign evaluation responsibilities, monitor progress, discuss improvements and emerging difficulties, and agree on actions to be undertaken by individual members. The evaluated data and bibliographic details are made available to users via various media, such as the journals ''Nuclear Physics A'' and ''Nuclear Data Sheets'', the World Wide Web, on CD-ROM, wall charts of the nuclides and ''Nuclear Wallet Cards''. While the ENSDF master database is maintained by the US National Nuclear Data Center at the Brookhaven National Laboratory, these data are also available from other nuclear data centers including the IAEA Nuclear Data Section. The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy, in cooperation with the IAEA, organizes workshops on NSDD at regular intervals. The primary aims of these particular workshops are to provide hands-on training in the data evaluation processes, and to encourage new evaluators to participate in NSDD activities. The technical contents of these NSDD workshops are described, along with the rationale for the inclusion of various topics.

  11. Effects of heat-activated persulfate oxidation on soil microorganisms

    DEFF Research Database (Denmark)

    Tsitonaki, Aikaterini; Smets, Barth F.; Bjerg, Poul Løgstrup

    2008-01-01

    The effects of heat-activated persulfate on indigenous microorganisms and microcosms augmented with Pseudomonas putida KT2440 were studied in laboratory batch reactors with aquifer material. Microscopic enumeration was used to measure the changes in cell density, and acetate consumption was used to....../L). The results emphasize the necessity of using multiple toxicity assays and indigenous cultures in order to realistically assess the potential effects of in situ chemical oxidation on soil microorganisms. A comparison to other studies suggests that the effects of activated persulfate on soil...

  12. [Physical activity in the heat: physiology of hydration recommendations].

    Science.gov (United States)

    Koulmann, N; Banzet, S; Bigard, A X

    2003-01-01

    Physical exercise in the heat causes severe disturbances in homeostasis. The need for evaporative thermolysis is increased due to the combination of endogenous and exogenous heat production. Despite a marked increase in cardiac output, muscles and skin must compete for sufficient blood flow. In addition progressive dehydration can impair the ability of the cardiocirculatory to adjust adequately. The most serious risk associated with exercise in a hot environment is heat stroke. Although deleterious effects of dehydration occur only if large amounts of water and electrolytes are lost without being replaced, even moderate fluid depletion can reduce both physical and cognitive performance. Another mechanism by which heat exposure directly affects performance involves core temperature elevation which can induce profound changes in muscular activity and energy consumption, thereby accelerating exhaustion. Prevention of deleterious effects on health and performance requires an effective rehydration strategy to maintain body fluid balance. This strategy must optimize all three potentially limiting factors for fluid replacement, i.e., fluid intake, gastric emptying, and intestinal absorption. Practical guidelines are given to answer the questions of when, what and how much to drink. PMID:15077428

  13. Chemical composition and inhibitory activity of essential oil from decaying leaves of Eucalyptus citriodora.

    Science.gov (United States)

    Batish, Daizy R; Singh, Harminder Pal; Setia, Nidhi; Kaur, Shalinder; Kohli, Ravinder K

    2006-01-01

    A study was undertaken to explore the content and composition of volatile oil from decaying leaves of lemon-scented eucalypt (Eucalyptus citriodora Hook.) not analyzed earlier. GC and GC-MS analysis of the oil (yield 0.6%) revealed the monoterpenoid nature with citronellal (52.2%), citronellol (12.3%) and isoisopulegol (11.9%) as the major constituents. Overall, 17 components were identified that accounted for over 94% of the decaying leaf oil. Surprisingly, the decaying leaf oil contained nearly 1.8% of trans-rose oxide, which is generally absent in eucalypt essential oil. Decaying leaf oil and its major 2 components (citronellal and citronellol) inhibited the germination and root elongation of two weeds--Cassia occidentalis (broad-leaved) and Echinochloa crus-galli (grassy weed). Based on the dose-response studies, I50 values were determined for decaying leaf oil and the effect was more on germination only of broad-leaved weed (C. occidentalis), whereas that of citronellal and citronellol were on germination as well as root length of E. crus-galli (grassy weed). Based on I50 values it was observed that citronellal was more phytotoxic and germination inhibiting in nature, whereas citronellol was a more potent root inhibitor, thereby indicating a possible different mode of action. The study concludes that decaying leaf oil hold a good commercial value for exploitation as weed management agent. PMID:16610217

  14. Impact of active geomagnetic conditions on stimulated radiation during ionospheric second electron gyroharmonic heating

    Science.gov (United States)

    Bordikar, M. R.; Scales, W. A.; Mahmoudian, A.; Kim, H.; Bernhardt, P. A.; Redmon, R.; Samimi, A. R.; Brizcinski, S.; McCarrick, M. J.

    2014-01-01

    Recently, narrowband emissions ordered near the H+ (proton) gyrofrequency (fcH) were reported in the stimulated electromagnetic emission (SEE) spectrum during active geomagnetic conditions. This work presents new observations and theoretical analysis of these recently discovered emissions. These emission lines are observed in the stimulated electromagnetic emission (SEE) spectrum when the transmitter is tuned near the second electron gyroharmonic frequency (2fce) during recent ionospheric modification experiments at the High Frequency Active Auroral Research (HAARP) facility near Gakona, Alaska. The spectral lines are typically shifted below and above the pump wave frequency by harmonics of a frequency roughly 10% less than fcH (≈ 800 Hz) with a narrow emission bandwidth less than the O+ gyrofrequency (≈ 50 Hz). However, new observations and analysis of emission lines ordered by a frequency approximately 10% greater than fcH are presented here for the first time as well. The interaction altitude for the heating for all the observations is in the range of 160 km up to 200 km. As described previously, proton precipitation due to active geomagnetic conditions is considered as the reason for the presence of H+ ions known to be a minor background constituent in this altitude region. DMSP satellite observations over HAARP during the heating experiments and ground-based magnetometer and riometer data validate active geomagnetic conditions. The theory of parametric decay instability in multi-ion component plasma including H+ ions as a minority species described in previous work is expanded in light of simultaneously observed preexisting SEE features to interpret the newly reported observations. Impact of active geomagnetic conditions on the SEE spectrum as a diagnostic tool for proton precipitation event characterization is discussed.

  15. Effect of heat treatment on antimycotic activity of Sahara honey

    Institute of Scientific and Technical Information of China (English)

    Moussa Ahmed; Saad Aissat; Noureddine Djebli

    2014-01-01

    Objective: To evaluate the influence of the temperature on honey colour, polyphenol contents and antimycotic capacity and to evaluate the correlation between these parameters. Methods:Sahara honey were heated up to 25, 50, 75 and 100 °C for 15, 30 and 60 min, and their colour intensity, polyphenol contents and antimycotic capacity. The Folin-Ciocalteu test was used to determine the total polyphenol contents (TPC). The antimycotic activity was evaluated both by agar diffusion method and micro wells dilution method against the Candida albicans (C. albicans) and Candida glabrata (C. glabrata). Results:Initial values for TPC in Sahara honey ranged from 0.55 to 1.14 mg of gallic acid per kg of honey, with the average value of 0.78 mg of gallic acid per kg of honey. The TPC values after heat-treatment were 0.54 to 1.54 with the average value of 1.49 mg. The minimal inhibitory concentrations before heat-treatment of Sahara honey against C. albicans and C. glabrata ranged from 3.06%-12.5% and 50% respectively. After heat-treatment the minimal inhibitory concentrations between 12.5% and 50% for C. albicans and C. glabrata, respectively. The diameters of inhibition zones of Sahara honey with 50% concentration varied from (12.67-15.00) mm by C. albicans to (14.33-15.67) mm by C. glabrata. The diameters of inhibition zones after heat-treatment at 25 and 50 °C for 15.30 and 60 min ranged from (2.00-18.67) mm by C. albicans to (8.00-16.67) mm by C. glabrata. Statistically significant relations between the TPC and the colour intensity of Sahara honey (r=0.99, P Conclusions:To our knowledge this is the first report on the antimycotic capacity of Sahara honey.

  16. Active heat exchange system development for latent heat thermal energy storage

    Science.gov (United States)

    Alario, J.; Haslett, R.

    1980-03-01

    Various active heat exchange concepts were identified from among three generic categories: scrapers, agitators/vibrators and slurries. The more practical ones were given a more detailed technical evaluation and an economic comparison with a passive tube-shell design for a reference application. Two concepts selected for hardware development are a direct contact heat exchanger in which molten salt droplets are injected into a cooler counterflowing stream of liquid metal carrier fluid, and a rotating drum scraper in which molten salt is sprayed onto the circumference of a rotating drum, which contains the fluid heat sink in an internal annulus near the surface. A fixed scraper blade removes the solidified salt from the surface which has been nickel plated to decrease adhesion forces. Suitable phase change material (PCM) storage media with melting points in the temperature range of interest (250 C to 400 C) were investigated. The specific salt recommended for laboratory tests was a chloride eutectic (20.5KCl-24/5 NaCl-55.0MgCl 2% by wt.), with a nominal melting point of 385 C.

  17. 熔岩玻璃体核素衰变热功率的计算%Calculation of Radionuclide Decay Heat Power for Melt Glass

    Institute of Scientific and Technical Information of China (English)

    包敏; 王群书; 师全林; 解峰; 王武尚

    2014-01-01

    As the temperature is a key factor affecting melt glass dissolution rate ,the decay heat power generated by radionuclides within melt glass from 10 d to 300 000 d after an underground nuclear test was calculated to assess its influence on temperature and dissolution rate .Radioactive inventories with half-life longer than 1 a ,produced by 100 kt TNT nuclear explosion published by IAEA report were used .The inventories of short-lived fission products with half-life of 1 d-1 a and accumulate yield greater than 0.1% were estimated from the inventory of 137Cs .The decay characteristics of each nuclide were analyzed .The decay energy deposited in melt glass was calculated by the mean alpha , beta and gamma energy released by radioactive decay from ENDF/B Ⅶdatabase .From the calculation ,it can be concluded that the decay heat power decays by power function ,short-lived fission products ,long-lived fission products and actinides are the main contributions to the power at 10-2 000 d , 2 000-60 000 d and after 60 000 d ,respectively .T he influence on melt glass temperature and dissolution rate is indistinctive ,especially after 1 000 d .%温度是影响熔岩玻璃体溶解速度的关键因素,为此,本文计算了核试验后10~300000d内熔岩玻璃体中核素衰变热功率,评估了核素衰变热功率对熔岩玻璃体的温度和溶解速度的影响程度。采用了国际原子能机构给出的100ktTNT当量地下核试验产生的、半衰期大于1a的放射性核素含量,利用其中裂变产物核素137Cs的含量推算累积裂变产额大于0.1%、半衰期为1d~1a的短寿命裂变产物核素的含量。分析了各核素的放射性衰变特点,采用ENDF/BⅦ库中核素衰变辐射的平均α能量、平均电子能量和平均电磁辐射能量计算各核素在熔岩玻璃体内因衰变而沉积的能量。计算结果表明:核素衰变热功率呈分段幂函数衰减;在10~2000d、2000~60000d和60000d之后的时

  18. The Influence of Aerosol Concentration on Changes in the Volumetric Activities of Indoor Radon Short-Term Decay Products

    Directory of Open Access Journals (Sweden)

    Diana Politova

    2011-02-01

    Full Text Available The article describes the influence of aerosol concentration on changes in the volumetric activities of indoor radon short-term decay products. The concentration of aerosol in the air, equilibrium factors and unattached fraction were measured under normal living conditions when the concentration of aerosol increases, i.e. burning a candle or frankincense in accommodations, smoke-filled accommodations, a steamy kitchen etc. It has been established that when the concentration of aerosol in the air rises, the number of free atoms of radon short-term decay products attached to aerosol particles also increases, and therefore higher volumetric activity of alpha particles is fixed. A tight positive connection of the correlation between equilibrium factor (F and aerosol particle concentration in the air of accommodations as well as a negative correlation between unattached fraction and an equilibrium factor have been determined.Article in Lithuanian

  19. Biological activity, membrane-targeting modification, and crystallization of soluble human decay accelerating factor expressed in E. coli

    OpenAIRE

    White, Jennifer; Lukacik, Petra; Esser, Dirk; Steward, Michael; Giddings, Naomi; Bright, Jeremy R.; Fritchley, Sarah J.; Morgan, B. Paul; Lea, Susan M.; Smith, Geoffrey P.; Smith, Richard A. G.

    2004-01-01

    Decay-accelerating factor (DAF, CD55) is a glycophosphatidyl inositol-anchored glycoprotein that regulates the activity of C3 and C5 convertases. In addition to understanding the mechanism of complement inhibition by DAF through structural studies, there is also an interest in the possible therapeutic potential of the molecule. In this report we describe the cloning, expression in Escherichia coli, isolation and membrane-targeting modification of the four short consensus repeat domains of sol...

  20. Enzyme activity and effect of heat treatment on some fungal diseases of postharvest tomato fruits.

    Science.gov (United States)

    Amer, M A; El-Abd, S M; Mansour, F G F

    2013-01-01

    The activity of heat treatments for controlling tomato black mould caused by Alternaria alternata (Fr.) Keissler and grey mould caused by Botrytis cinerea Pers. Ex. Pers. wWas tested. Spore suspension of the grey mold pathogen which was exposed to hot water treatment at 58 degrees C for 6 min., failed to germinate, whereas A. alternata failed to germinate when exposed to hot water at 58 degrees C, for 8 min. Exposing discs bearing growth of any both tested fungi to hot air at 48 degrees C for 72 h caused growth suppression for the both tested pathogens. Dipping tomato fruits in hot water at 58 degrees C for 8 min or keeping in hot air for 72 h at 40 degrees C prevented decay development in non inoculated or artificially inoculated fruits with A. alternata and B. cinerea up to 12 days when stored at 24 degrees C. The high amount of polygalacturonase (PG) and pectinmethylestrase (BME) enzymes were investigated in infected fruits by the two tested pathogens as compared by healthy ones. The culture filtrate of A. alternata had the highest protease activity, white B. cinerea was the lowest. Protease activity was higher when CD liquid medium contain casein was used. PMID:25151835

  1. Decay heat measurement of 235U in the time region from 10 to 1,000 seconds

    International Nuclear Information System (INIS)

    In order to provide a good cooling of the fuel samples during irradiation in the thermal column of the FR2 reactor, vehicles for a pneumatic transfer system were developed and constructed which keep the fuel temperature at about 10 K above the temperature of the cooling gas (N2 at 1 atm and about 300 K). For these 'rabbits' a new transport system has to be designed. Together with the mechanical system inside the vacuum vessel, which contains the calorimeter, the samples can be transfered from the irradiation position into the adiabatic jacket automatically within 2 to 3 seconds. For the measurement of the decay energy escaping the samples as γ-radiation, a MOXON-RAE-type detector was constructed. As its sensitivity increases linearly with the energy of the γ-quanta detected, this counter directly measures the energy flux of an unknown γ-spectrum. (orig./RW)

  2. Heat Exchanger Anchors for Thermo-active Tunnels

    OpenAIRE

    Mimouni, Thomas; Dupray, Fabrice; Minon, Sophie; LALOUI, Lyesse

    2013-01-01

    Shallow geothermal power represents an important energy resource for the heating and cooling of the buildings. Due to relatively low temperature levels encountered at shallow depths in the soil, between 10°C and 20°C, heat pumps are required to process the extracted heat, forming the so called ground source heat pump system. Different types of heat exchangers with the ground were developed in order to optimize the heat exchanges, from simple geothermal loops grouted in boreholes reaching dept...

  3. Changes of spontaneous oscillatory activity to tonic heat pain.

    Directory of Open Access Journals (Sweden)

    Weiwei Peng

    Full Text Available Transient painful stimuli could induce suppression of alpha oscillatory activities and enhancement of gamma oscillatory activities that also could be greatly modulated by attention. Here, we attempted to characterize changes in cortical activities during tonic heat pain perception and investigated the influence of directed/distracted attention on these responses. We collected 5-minute long continuous Electroencephalography (EEG data from 38 healthy volunteers during four conditions presented in a counterbalanced order: (A resting condition; (B innoxious-distracted condition; (C noxious-distracted condition; (D noxious-attended condition. The effects of tonic heat pain stimulation and selective attention on oscillatory activities were investigated by comparing the EEG power spectra among the four experimental conditions and assessing the relationship between spectral power difference and subjective pain intensity. The change of oscillatory activities in condition D was characterized by stable and persistent decrease of alpha oscillation power over contralateral-central electrodes and widespread increase of gamma oscillation power, which were even significantly correlated with subjective pain intensity. Since EEG responses in the alpha and gamma frequency band were affected by attention in different manners, they are likely related to different aspects of the multidimensional sensory experience of pain. The observed contralateral-central alpha suppression (conditions D vs. B and D vs. C may reflect primarily a top-down cognitive process such as attention, while the widespread gamma enhancement (conditions D vs. A may partly reflect tonic pain processing, representing the summary effects of bottom-up stimulus-related and top-down subject-driven cognitive processes.

  4. 核电厂堆芯衰变热计算及影响因素分析%Calculation of Decay Heat Power and Analysis of Influence Factors for Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    陈海英; 王韶伟; 韩静茹; 谭怡; 张春明; 朱伟

    2014-01-01

    针对压水堆核电厂,采用ORIGEN-S程序分析燃料富集度、功率水平、燃耗深度、时间步长对堆芯衰变热计算的影响程度。结果表明,采用燃耗包络法计算衰变热时,燃耗在1000~6000(MW·d)/tU之间的取值应加密,辐照时间步长对衰变热影响不大,衰变时间步长对衰变热包络值的确定具有较大影响,总衰变热随着比功率的增大而增大,随富集度变化无明显规律性。%ORIGEN-S is used to analyze the effects of fuel enrichment ,specific power ,burnup ,irradiation time steps on PWR decay heat calculation .The results show that when the burnup envelope method is used to calculate decay heat ,the burnup between 1 000 and 6 000 MWd/tU should be refined .The irradiation time step has little effect on decay heat ,while the decay time step has a greater impact on the determination of the envelope value .The total decay heat increases with the increase of the specific power .There’s no obvious rule for the decay heat when the enrichment of fuel changes .

  5. HORMONAL FUNCTION OF TYROID GLAND AND MALE MUSKRAT GONADS IN THE PERIOD OF POSTNATAL ONTOGENESIS AND IN THE SEXUAL ACTIVITY DECAY PERIOD OF BAIKAL REGIONAL ECOSYSTEM

    OpenAIRE

    Silkin, I.

    2011-01-01

    Basing on their own observations the authors have analyzed the dynamics of hormones concentration in thyroid gland and male muskrat gonads depending on the stage of postnatal ontogenesis and in the sexual activity decay period. As a result a number of new regularities of thyroid gland hormonal activity function in age aspect and the sexual activity decay period in muskrat males inhabiting under conditions of Baikal regional ecosystem,have been revealed.

  6. Brain activity and fatigue during prolonged exercise in the heat

    DEFF Research Database (Denmark)

    Hyldig, Tino Hoffmann

    2001-01-01

    We hypothesized that fatigue due to hyperthermia during prolonged exercise in the heat is in part related to alterations in frontal cortical brain activity. The electroencephalographic activity (EEG) of the frontal cortex of the brain was measured in seven cyclists [maximal O2 uptake (VO2max) 4.......8-0.1 (SE) l min-1] cycling at 60% VO2max in a hot (H, 42°C) and a cool (C, 19°C) environment. Fast Fourier transformation of the EEG was used to obtain power spectrum areas in the ! (8-13 Hz) and # (13-30 Hz) frequencies. The ratio !/# was calculated as an index of arousal level; an elevated !/# index...

  7. Protein kinase A binds and activates heat shock factor 1.

    Directory of Open Access Journals (Sweden)

    Ayesha Murshid

    Full Text Available BACKGROUND: Many inducible transcription factors are regulated through batteries of posttranslational modifications that couple their activity to inducing stimuli. We have studied such regulation of Heat Shock Factor 1 (HSF1, a key protein in control of the heat shock response, and a participant in carcinogenisis, neurological health and aging. As the mechanisms involved in the intracellular regulation of HSF1 in good health and its dysregulation in disease are still incomplete we are investigating the role of posttranslational modifications in such regulation. METHODOLOGY/PRINCIPAL FINDINGS: In a proteomic study of HSF1 binding partners, we have discovered its association with the pleiotropic protein kinase A (PKA. HSF1 binds avidly to the catalytic subunit of PKA, (PKAcα and becomes phosphorylated on a novel serine phosphorylation site within its central regulatory domain (serine 320 or S320, both in vitro and in vivo. Intracellular PKAcα levels and phosphorylation of HSF1 at S320 were both required for HSF1 to be localized to the nucleus, bind to response elements in the promoter of an HSF1 target gene (hsp70.1 and activate hsp70.1 after stress. Reduction in PKAcα levels by small hairpin RNA led to HSF1 exclusion from the nucleus, its exodus from the hsp70.1 promoter and decreased hsp70.1 transcription. Likewise, null mutation of HSF1 at S320 by alanine substitution for serine led to an HSF1 species excluded from the nucleus and deficient in hsp70.1 activation. CONCLUSIONS: These findings of PKA regulation of HSF1 through S320 phosphorylation add to our knowledge of the signaling networks converging on this factor and may contribute to elucidating its complex roles in the stress response and understanding HSF1 dysregulation in disease.

  8. Absolute activity measurement and gamma-ray emission probability for decay of I-126

    International Nuclear Information System (INIS)

    The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of 126 I, its importance lies mainly in fast neutron dosimetry as well as in the production of 125 I where 126 I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of 126 I have been measured. This radionuclide was obtained by means of the 127 I(n, 2n)126 I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of 126 I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The βbranch measurement was carried out in a 4 π(PC)β-γ coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch was measured in a X-γ coincidence system using two NaI(Tl) crystals. The gamma-ray measurements were performed in a HPGe system, previously calibrated by means of standard sources supplied by the International Atomic Energy Agency. All the uncertainties evolved were treated rigorously, by means of covariance analysis. (author)

  9. Absolute activity measurement and gamma-ray emission probability for decay of I-126

    CERN Document Server

    Fonseca, K A

    1997-01-01

    The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of sup 1 sup 2 sup 6 I, its importance lies mainly in fast neutron dosimetry as well as in the production of sup 1 sup 2 sup 5 I where sup 1 sup 2 sup 6 I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of sup 1 sup 2 sup 6 I have been measured. This radionuclide was obtained by means of the sup 1 sup 2 sup 7 I(n, 2n) sup 1 sup 2 sup 6 I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of sup 1 sup 2 sup 6 I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The beta branch measurement was carried out in a 4 pi(PC)beta-gamma coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch ...

  10. Ion Heating Anisotropy during Dynamo Activity in the MST RFP

    Science.gov (United States)

    den Hartog, D. J.; Chapman, J. T.; Craig, D.; Fiksel, G.; Fontana, P. W.

    1999-11-01

    MHD dynamo activity is large in the MST Reversed-Field Pinch during sawtooth crashes, and small otherwise. During a sawtooth crash, ion temperature increases rapidly to a level several times as high as the temperature between sawteeth, which itself can be larger than the electron temperature. Several theories have been developed to explain this ion heating, some indicating a possible asymmetry in perpendicular to parallel heating [C. G. Gimblett, Europhys. Lett. 11, 541 (1990); Z. Yoshida, Nucl. Fusion 31, 386 (1991); N. Mattor, P. W. Terry, and S. C. Prager, Comments Plasma Phys. Controlled Fusion 15, 65 (1992)]. In standard MST discharges, impurity ion temperature measured perpendicular to the magnetic field (T_⊥) is higher than impurity ion temperature parallel to the magnetic field (T_allel) during a sawtooth crash. Throughout the rest of the sawtooth cycle, T_⊥ EXTRAP-T2 RFP which showed T_⊥ < T_allel throughout the discharge [K. Sasaki et al., Plasma Phys. Control. Fusion 39, 333 (1997)

  11. 不同级钚材料的衰变放热功率计算分析%Analysis of decay heat power generation for plutonium with various grades

    Institute of Scientific and Technical Information of China (English)

    左应红; 朱金辉

    2016-01-01

    Background: Radioactive nuclides contained in plutonium material will continually decay and release energy, which will change the temperature of plutonium materials and the surrounding components. Purpose:This study aims to analyze the releasing heat power of various grades plutonium materials in the process of bulk storage and transportation of plutonium. Methods:According to the isotopic quality composition of various grades plutonium, the time evolutions of decay heat power of each radioactive nuclide contained in weapons grade plutonium, reactor grade plutonium, and mixed oxide grade plutonium are obtained. And the total decay heat power of various grades plutonium as a function of time is also calculated, on the basis of the analysis of radionuclide decay cascade regulation, with the energy branching ratios during decay in the physical model taken into consideration. Results:The calculation results showed that the decay heat power varied with the grades of plutonium material. For 1-kg different grades plutonium material, the maximum decay heat power quantity is released by mixed oxide grade plutonium, while the weapons grade plutonium releases the least decay heat power quantity. The heat power released by weapons grade plutonium is mainly from 239Pu, while the main heat power is from 241Pu and 238Pu for the reactor and mixed oxide grade plutonium material. The decay heat power released by 242Pu is few compared with other nuclides for the three grades of plutonium materials. Conclusion: The releasing decay heat power of plutonium materials can be calculated more accurately by considering the energy branching ratios.%钚材料中放射性核素会不断衰变并释放能量,改变钚材料及周围部件的温度。为研究不同级钚材料在其整装存储及运输过程中衰变放热功率随时间的变化规律,依据不同级钚材料的放射性核素组分,在分析核素级联衰变规律的基础上,并在物理模型中考虑衰变时的

  12. Active solar heating and cooling information user study

    Energy Technology Data Exchange (ETDEWEB)

    Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

    1981-01-01

    The results of a series of telephone interviews with groups of users of information on active solar heating and cooling (SHAC). An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from 19 SHAC groups respondents are analyzed in this report: DOE-Funded Researchers, Non-DOE-Funded Researchers, Representatives of Manufacturers (4 groups), Distributors, Installers, Architects, Builders, Planners, Engineers (2 groups), Representatives of Utilities, Educators, Cooperative Extension Service County Agents, Building Owners/Managers, and Homeowners (2 groups). The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

  13. Sawtooth Activity in Ohmically Heated Plasma on HT-7 Tokamak

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Sawtooth activity on HT-7 tokamak has been investigated experimentally mainly by using soft x-ray diode array and magnetic probes. Their behaviors and occurrences are correlatedclosely to the discharge conditions: the electron density Ne, the electron temperature Te, the safetyfactor qa on plasma boundary and wall condition etc. When central line-averaged electron densityNe(0) is over 2.0×1013cm-3, major sawtooth activity emerges with a period of up to 6.5 ms and afluctuation amplitude of up to 2~30 % of SXR radiation signal. In some cases such as the safetyfactor between 4.2~4.7 and Zeff=3.0~6.0, a monster sawtooth activity often emerges withoutapparent deterioration of plasma confinement and without major disruption. During these events,abundant MHD phenomena are observed including partial sawtooth oscillations. In this paper, theobserved sawtooth behaviors and their dependence on the and their dependence density Ne andwall condition in ohmically heated plasma are introduced, the results are discussed and presented.

  14. Microbial activity and soil organic matter decay in roadside soils polluted with petroleum hydrocarbons

    Science.gov (United States)

    Mykhailova, Larysa; Fischer, Thomas; Iurchenko, Valentina

    2015-04-01

    It has been demonstrated previously that hydrocarbon addition to soil provokes soil organic matter priming (Zyakun et al., 2011). It has further been shown that petroleum hydrocarbons deposit to roadside soils bound to fine mineral particles and together with vehicle spray (Mykhailova et al., 2014), and that hydrocarbon concentrations decrease to safe levels within the first 15 m from the road, reaching background concentrations at 60-100 m distance (Mykhailova et al., 2013). It was the aim of this study to (I) identify the bioavailability of different petroleum hydrocarbon fractions to degradation and to (II) identify the native (i.e. pedogenic) C fraction affected by hydrocarbon-mediated soil organic matter priming during decay. To address this aim, we collected soil samples at distances from 1 to 100 m (sampling depth 15 cm) near the Traktorostroiteley avenue and the Pushkinskaya street in Kharkov, as well as near the country road M18 near Kharkov, Ukraine. The roads have been under exploitation for several decades, so microbial adaptation to enhanced hydrocarbon levels and full expression of effects could be assumed. The following C fractions were quantified using 13C-CP/MAS-NMR: Carbohydrates, Proteins, Lignin, Aliphates, Carbonyl/Carboxyl as well as black carbon according to Nelson and Baldock (2005). Petroleum hydrocarbons were determind after hexane extraction using GC-MS and divided into a light fraction (chain-length C27, Mykhailova et al., 2013). Potential soil respiration was determined every 48 h by trapping of CO2 evolving from 20 g soil in NaOH at 20 ° C and at 60% of the maximum water holding capacity and titration after a total incubation period of 4 weeks in the lab. It was found that soil respiration positively correlated with the ratio of the light fraction to the sum of medium and heavy fractions of petroleum hydrocarbons, which indicates higher biodegradation primarily of the light petroleum hydrocarbon fraction. Further, soil respiration was

  15. Cosmogenic-neutron activation of TeO2 and implications for neutrinoless double-beta decay experiments

    CERN Document Server

    Wang, Barbara S; Scielzo, Nicholas D; Smith, Alan R; Thomas, Keenan J; Wender, Stephen A

    2015-01-01

    Flux-averaged cross sections for cosmogenic-neutron activation of natural tellurium were measured using a neutron beam containing neutrons of kinetic energies up to $\\sim$800 MeV, and having an energy spectrum similar to that of cosmic-ray neutrons at sea-level. Analysis of the radioisotopes produced reveals that 110mAg will be a dominant contributor to the cosmogenic-activation background in experiments searching for neutrinoless double-beta decay of 130Te, such as CUORE and SNO+. An estimate of the cosmogenic-activation background in the CUORE experiment has been obtained using the results of this measurement and cross-section measurements of proton activation of tellurium. Additionally, the measured cross sections in this work are also compared with results from semi-empirical cross-section calculations.

  16. Energy-Storage Modules for Active Solar Heating and Cooling

    Science.gov (United States)

    Parker, J. C.

    1982-01-01

    34 page report describes a melting salt hydrate that stores 12 times as much heat as rocks and other heavy materials. Energy is stored mostly as latent heat; that is, heat that can be stored and recovered without any significant change in temperature. Report also describes development, evaluation and testing of permanently sealed modules containing salt hydrate mixture.

  17. Radon and its decay product activities in the magmatic area and the adjacent volcano-sedimentary Intrasudetic Basin

    Directory of Open Access Journals (Sweden)

    D. Tchorz

    2007-06-01

    Full Text Available In the magmatic area of Sudetes covering the Karkonosze granite and adjacent volcano-sedimentary Intrasudetic Basin a study of atmospheric radon activity was performed by means of SSNTD Kodak LR-115. The study was completed by gamma spectrometric survey of eU and eTh determined by gamma activity of radon decay products 214Bi and 208Tl respectively. In the case of the western part of the Karkonosze granite area the radon decay products activity in the granitic basement was found to be as high as 343 Bq/kg for 214Bi and 496 Bq/kg for 208Tl respectively. Atmospheric radon content measured by means of Kodak LR115 track detector at the height of 1.5 m was found as high as 70 Bq/m3 in the regions, where no mining activities took place. However in the eastern part of the granitic massif in the proximity of abandoned uranium mine atmospheric radon content was found to be 6000 Bq/m3. In the case of sedimentary basin where sedimentary sequence of Carboniferous rocks has been penetrated by younger gases and fluids of volcanic origin uranium mineralization developed. The region known from its CO2 outburst during coal mining activity is characterized by good ventilation of the uranium enriched geological basement resulting in increased atmospheric radon activity being in average 72 Bq/m3. In the vicinity of coal mine tailing an increase up to 125 Bq/m3 can be observed. Seasonal variations of atmospheric radon content are influenced in agricultural areas by cyclic cultivation works (plough on soils of increased uranium content and in the case of post-industrial brownfields varying rates of radon exhalation from tailings due to different meteorological conditions.

  18. Stress-Specific Activation and Repression of Heat Shock Factors 1 and 2

    OpenAIRE

    Mathew, Anu; Mathur, Sameer K.; Jolly, Caroline; Fox, Susan G.; Kim, Soojin; Richard I Morimoto

    2001-01-01

    Vertebrate cells express a family of heat shock transcription factors (HSF1 to HSF4) that coordinate the inducible regulation of heat shock genes in response to diverse signals. HSF1 is potent and activated rapidly though transiently by heat shock, whereas HSF2 is a less active transcriptional regulator but can retain its DNA binding properties for extended periods. Consequently, the differential activation of HSF1 and HSF2 by various stresses may be critical for cells to survive repeated and...

  19. The Chemistry of Self-Heating Food Products: An Activity for Classroom Engagement

    Science.gov (United States)

    Oliver-Hoyo, Maria T.; Pinto, Gabriel; Llorens-Molina, Juan Antonio

    2009-01-01

    Two commercial self-heating food products have been used to apply chemical concepts such as stoichiometry, enthalpies of reactions and solutions, and heat transfer in a classroom activity. These products are the self-heating beverages sold in Europe and the Meals, Ready to Eat or MREs used primarily by the military in the United States. The main…

  20. 球床式高温气冷堆的余热不确定性分析%Uncertainty Analysis on Decay Heat of Pebble-bed High Temperature Gas-cooled Reactor

    Institute of Scientific and Technical Information of China (English)

    贠相羽; 郑艳华; 经荥清; 李富

    2013-01-01

    反应堆在停堆后相当长时间内仍具有较高的剩余发热是核电站的重要特性,也是核电站安全分析的关键.因此,对反应堆余热及其不确定性进行分析,对于合理设计余热排出系统、研究论证燃料元件在事故后的安全特性等均具有重要意义.本工作结合德国针对球床式高温气冷堆制定的余热计算标准,介绍了球床式高温气冷堆剩余发热及其不确定性的计算方法,并结合200 MWe球床模块式高温气冷堆示范工程(HTR-PM)的初步物理设计,对长期运行在满功率平衡堆芯状态下的反应堆停堆后的余热及其不确定性进行了计算分析,为进一步的事故分析提供依据.%The large amount of decay heat in a quite long time after reactor shutdown,which is an important characteristic of the nuclear power plants,should be considered seriously during the safety analysis.Therefore,the study on the decay heat and its uncertainty analysis play an important role in the design of decay heat removal system,as well as in the safety verification of the fuel element during the accident.In referenced to the standard of Germany entitled "Decay Heat Power in Nuclear Fuels of Hightemperature Reactors with Spherical Fuel Elements" especially for pebble-bed high temperature gas-cooled reactor (HTGR),the calculation method of decay heat and its uncertainty of pebble-bed HTGR were introduced.On the basis of the preliminary physical design of Chinese 200 MWe high temperature gas-cooled reactor pebble-bed module (HTR-PM),the decay heat and its uncertainty after reactor shutdown from long-term operation at rated power were analyzed,so as to provide a basis for further accident analysis.

  1. Degradation of Biochemical Activity in Soil Sterilized by Dry Heat and Gamma Radiation

    Science.gov (United States)

    Shih, K. L.; Souza, K. A.

    1978-01-01

    The effect of soil sterilization by dry heat (0.08% relative humidity), gamma radiation, or both on soil phosphatase, urease, and decarboxylase activity was studied. Soil sterilized by a long exposure to dry heat at relatively low temperatures (eight weeks at 100.5 C) retained higher activities than did soil exposed to a higher temperature (two weeks at 124.5 C), while all activity was destroyed by four days at 148.5 C. Sterilization with 7.5 Mrads destroyed less activity than did heat sterilization. The effect of several individually nonsterizing doses of heat radiation is described.

  2. Study on the decay resistance and chemical properties of heat treated masson's pine wood with N2%马尾松N2热处理材耐腐性能及化学性质的研究

    Institute of Scientific and Technical Information of China (English)

    陈居静; 陈瑞英; 马军军

    2012-01-01

    Uniform design experimentation was used to conduct decay resistance and chemical properties of heat treated masson's pine wood in the medium of nitrogen (N2). The results showed that the decay resistance was improved with the treatment temperature increasing and heat preservation time prolonged. The cellulose decreased by 0.9% and the semi-jcellulose decreased by 6.5% after heat treated. The fourier transform infrared spectroscopy (FTIR) analysis showed that: after treated, the O—H decreased. The optimum technology of heat treatment of masson's pine wood with N2 as a medium is; temperature 220℃ , heat preservation time 4 hours, temperature increasing rate 15℃min-1, the weight-loss ratio of treated wood is 16.4% after decayed, reached the level 2 of the decay resistance.%采用均匀设计法探讨氮气(N2)热处理工艺对人工林马尾松木材耐腐性能及化学性质的影响.结果表明,随处理温度升高,保温时间增加,木材耐腐性能提高;N2热处理使其纤维素含量减少0.9%,半纤维素减少6.5%.红外光谱分析(FTIR)表明,N2热处理使木材内部O-H减少.马尾松N2热处理的较佳工艺条件:处理温度220℃,保温时间4h,升温速率15℃·min -1,此时处理材腐朽后失重率16.4%,已达到Ⅱ级(耐腐).

  3. The pleiotropic activity of heat-shock proteins

    Directory of Open Access Journals (Sweden)

    Arleta Kaźmierczuk

    2009-10-01

    Full Text Available Stress or heat-shock proteins (HSPs are highly conserved proteins present in cells of both prokaryotes and eukaryotes, providing them with protection from cellular and environmental stress factors. Based on molecular-weight, HSPs can be divided into the large (HSP100: 100–110 kDa and HSP90: 75–96 kDa, intermediate (HSP70: 66–78 kDa, HSP60, and HSP40, and small (sHSP: 8.5–40 kDa subfamilies. These proteins play an essential role as molecular chaperones/co-chaperones by assisting the correct folding of nascent and stress-accumulated protein-substrate assembly, preventing the aggregation of these proteins, as well as transport across membranes and the degradation of other proteins. Members of HSP family display dual activity depending on their intra- or extracellular distribution. Intracellular HSPs mainly play a protective role. Extracellular or membrane-bound HSPs mediate immunological functions. Among the functions of HSPs is their participation in cell signaling. This review deals with the structure and properties of the main members of the HSPs and their role in a large number of cellular/extracellular processes.

  4. HEAT INPUT AND POST WELD HEAT TREATMENT EFFECTS ON REDUCED-ACTIVATION FERRITIC/MARTENSITIC STEEL FRICTION STIR WELDS

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Wei [ORNL; Chen, Gaoqiang [ORNL; Chen, Jian [ORNL; Yu, Xinghua [ORNL; Frederick, David Alan [ORNL; Feng, Zhili [ORNL

    2015-01-01

    Reduced-activation ferritic/martensitic (RAFM) steels are an important class of structural materials for fusion reactor internals developed in recent years because of their improved irradiation resistance. However, they can suffer from welding induced property degradations. In this paper, a solid phase joining technology friction stir welding (FSW) was adopted to join a RAFM steel Eurofer 97 and different FSW parameters/heat input were chosen to produce welds. FSW response parameters, joint microstructures and microhardness were investigated to reveal relationships among welding heat input, weld structure characterization and mechanical properties. In general, FSW heat input results in high hardness inside the stir zone mostly due to a martensitic transformation. It is possible to produce friction stir welds similar to but not with exactly the same base metal hardness when using low power input because of other hardening mechanisms. Further, post weld heat treatment (PWHT) is a very effective way to reduce FSW stir zone hardness values.

  5. Heating effects on physicochemical characteristics and antioxidant activity of flaxseed hull oil (Linum usitatissimum L

    Directory of Open Access Journals (Sweden)

    Wahid HERCHI

    2016-01-01

    Full Text Available The aim of this study was to analyze the effects of heating on some quality characteristics and antioxidant activity of flaxseed hull oil. Polyunsaturated fatty acids (PUFA and Cox value decreased during heating. Heating process led to considerable increase in saponification value (SV, peroxide value (PV, p-anisidine value (p-AnV, oxidative value (OV and specific extinction at 232 and 270 nm. There was a significant decrease in oil stability during heating process (1.4-1.0 h. Fuel properties of flaxseed hull oil were also changed after heating treatment. Heating process caused loss of total phenolic acids, total flavanoids, carotenoids and chlorophyll pigments. Phospholipids (PL content were less changed compared to other bioactive compounds. Antioxidant activity of flaxseed hull oil decreased during heating process.

  6. Effects of heat on the biological activity of wild Cordyceps sinensis

    Directory of Open Access Journals (Sweden)

    Pengkai Wu

    2015-01-01

    Conclusions: These results suggested that heat treatment does not adversely affect SOD or DNase activity, polysaccharide content, or cordycepin dissolution. Thus, heat treatment might be a safe processing method to extend the storage time of wild C. sinensis without compromising biological activity.

  7. Performance of active solar space-heating systems, 1980-1981 heating season

    Energy Technology Data Exchange (ETDEWEB)

    Welch, K.; Kendall, P.; Pakkala, P.; Cramer, M.

    1981-01-01

    Data are provided on 32 solar heating sites in the National Solar Data Network (NSDN). Of these, comprehensive data are included for 14 sites which cover a range of system types and solar applications. A brief description of the remaining sites is included along with system problems experienced which prevented comprehensive seasonal analyses. Tables and discussions of individual site parameters such as collector areas, storage tank sizes, manufacturers, building dimensions, etc. are provided. Tables and summaries of 1980-1981 heating season data are also provided. Analysis results are presented in graphic form to highlight key summary information. Performance indices are graphed for two major groups of collectors - liquid and air. Comparative results of multiple NSDN systems' operation for the 1980-1981 heating season are summarized with discussions of specific cases and conclusions which may be drawn from the data. (LEW)

  8. Numerical model of heat conduction in active volcanoes induced by magmatic activity

    Science.gov (United States)

    Atmojo, Antono Arif; Rosandi, Yudi

    2015-09-01

    We study the heat transfer mechanism of active volcanoes using the numerical thermal conduction model. A 2D model of volcano with its conduit filled by magma is considered, and acts as a constant thermal source. The temperature of the magma activity diffuses through the rock layers of the mountain to the surface. The conduction equation is solved using finite-difference method, with some adaptations to allow temperature to flow through different materials. Our model allows to simulate volcanoes having dikes, branch-pipes, and sills by constructing the domain appropriately, as well as layers with different thermal properties. Our research will show the possibility to monitor magma activity underneath a volcano by probing its surface temperature. The result of our work will be very useful for further study of volcanoes, eruption prediction, and volcanic disaster mitigation.

  9. Heat-activated Plasmonic Chemical Sensors for Harsh Environments

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, Michael [SUNY Polytechnic Inst., Albany, NY (United States); Oh, Sang-Hyun [Univ. of Minnesota, Minneapolis, MN (United States)

    2015-12-01

    A passive plasmonics based chemical sensing system to be used in harsh operating environments was investigated and developed within this program. The initial proposed technology was based on combining technologies developed at the SUNY Polytechnic Institute Colleges of Nanoscale Science and Engineering (CNSE) and at the University of Minnesota (UM). Specifically, a passive wireless technique developed at UM was to utilize a heat-activated plasmonic design to passively harvest the thermal energy from within a combustion emission stream and convert this into a narrowly focused light source. This plasmonic device was based on a bullseye design patterned into a gold film using focused ion beam methods (FIB). Critical to the design was the use of thermal stabilizing under and overlayers surrounding the gold film. These stabilizing layers were based on both atomic layer deposited films as well as metal laminate layers developed by United Technologies Aerospace Systems (UTAS). While the bullseye design was never able to be thermally stabilized for operating temperatures of 500oC or higher, an alternative energy harvesting design was developed by CNSE within this program. With this new development, plasmonic sensing results are presented where thermal energy is harvested using lithographically patterned Au nanorods, replacing the need for an external incident light source. Gas sensing results using the harvested thermal energy are in good agreement with sensing experiments, which used an external incident light source. Principal Component Analysis (PCA) was used to reduce the wavelength parameter space from 665 variables down to 4 variables with similar levels of demonstrated selectivity. The method was further improved by patterning rods which harvested energy in the near infrared, which led to a factor of 10 decrease in data acquisition times as well as demonstrated selectivity with a reduced wavelength data set. The combination of a plasmonic-based energy harvesting

  10. Tau decays

    International Nuclear Information System (INIS)

    The most recent experimental results of τ physics are reviewed. The covered topics include precision measurements of semihadronic τ decay and their impact on tau branching ratio budget, the current status of the tau consistency test, a determination of Michel parameters and τ neutrino helicity, and upper limits on lepton-number violating τ decays. (orig.)

  11. N2热处理马尾松木材的耐腐性能%The decay resistance property of Pinus massoniana Lamb.wood with heat treatment of N2

    Institute of Scientific and Technical Information of China (English)

    陈居静; 陈瑞英; 马军军

    2013-01-01

    以氮气(N2)为介质,采用均匀设计法对人工林马尾松木材进行热处理,探讨处理工艺对木材耐腐性能及物理力学性质的影响.结果表明:经过N2热处理的木材,尺寸稳定性能明显提高,密度、顺纹抗压强度略有下降.处理材腐朽后质量损失率为16.4%,耐腐性能达到Ⅱ级.SEM分析表明:处理材的结构基本完好,腐朽程度较素材轻得多,说明木材的耐腐性能明显提高.马尾松木材N2热处理的较佳工艺条件为:处理温度220℃,保温时间4h,升温速率15℃·min-1.%By uniform design experimentation, the effects of heat treatment technology in the medium of N2 on the decay resistance and physical-mechanical properties of Pinus massoniana Lamb, wood were investigated. The results were as follows; the dimensional stability of heat treated wood improved obviously, and the density and compressive strength parallel to grain decreased a bit; the mass loss ratio of treated wood was 16.4% after decay, reached level 2 (decay resistance level). SEM analysis showed the structure of treated wood was basically intact, and the decayed degree was lower than untreated wood, thus the decay resistance property of wood improved obviously. The optimum process of heat treated Pinus massoniana Lamb, wood treated with N2 as medium was as follows; temperature of 220 ℃ , heat preservation time of 4 hour, heating rate of 15 ℃·min-1.

  12. Active space heating and hot water supply with solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Karaki, S.; Loef, G. O.G.

    1981-04-01

    Technical and economic assessments are given of solar water heaters, both circulating, and of air-based and liquid-based solar space heating systems. Both new and retrofit systems are considered. The technical status of flat-plate and evacuated tube collectors and of thermal storage is also covered. Non-technical factors are also briefly discussed, including the participants in the use of solar heat, incentives and deterrents. Policy implications are considered as regards acceleration of solar use, goals for solar use, means for achieving goals, and interaction of governments, suppliers, and users. Government actions are recommended. (LEW)

  13. Visible light active photocatalyst from recycled disposable heating pads

    Science.gov (United States)

    Lee, Meng-Chien; Wang, Chun-Yu; Chen, Che-Chin; Wang, Chih-Ming; Hsiao, Ta-Chih; Tsai, Din Ping

    2016-01-01

    Alpha-Fe2O3 (α-Fe2O3) is cheap and abundant and has potential to be a highly efficient photocatalyst for water splitting. According to the report, there are a huge amount of disposable heating pads being created every year, and the pads are used one time then thrown away. We found that the main product of used heating pads is α-Fe2O3. Here, we collect and purify the α-Fe2O3 powder in the used heating pads using low power consumption processes. It is shown that the recycled heating pads can be used as a cost-effective photocatalyst for H2 energy and for decomposition of organic pollutants as well. Additionally, the plasmonic enhanced photocatalysis reaction of α-Fe2O3 is also investigated. It is found that H2 evolution rate can be enhanced 15% using α-Fe2O3 nanoparticles coated with a thin Au layer. The degradation of methylene blue can also enhance 12% compared to photocatalyst α-Fe2O3 nanoparticles coated without Au layer.

  14. 池式研究堆衰变热计算与实验研究%Research on Decay Heat Calculation and Measurement for Pool-Type Research Reactor

    Institute of Scientific and Technical Information of China (English)

    黄洪文; 刘汉刚; 米向秒; 钱达志; 杨晓斌; 黄文; 张之华

    2012-01-01

    The heat-measurement method is adopted to measure the decay heat of a nuclear reactor during 45.0 hours after the rated power operation of 75.0 hours; an empirical formula is fitted according to the experimental data. Several calculation empirical formulas used to calculate the residual power of a nuclear reactor and comparison with the test result indicated that the heat-measurement method could be used to measure the decay heat of a reactor, and the data is conformed to the standard of EJ/T 745.%采用量热法测量反应堆额定功率运行75.0 h停堆后45 h内的衰变热功率,拟合出归一化衰变热功率的经验关系式.与反应堆衰变热几种半经验公式和标准对比结果表明,实验结果在经验公式计算值范围内,并与EJ/T 745标准预测值符合较好.

  15. Annual DOE active solar heating and cooling contractors' review meeting. Premeeting proceedings and project summaries

    Energy Technology Data Exchange (ETDEWEB)

    None,

    1981-09-01

    Ninety-three project summaries are presented which discuss the following aspects of active solar heating and cooling: Rankine solar cooling systems; absorption solar cooling systems; desiccant solar cooling systems; solar heat pump systems; solar hot water systems; special projects (such as the National Solar Data Network, hybrid solar thermal/photovoltaic applications, and heat transfer and water migration in soils); administrative/management support; and solar collector, storage, controls, analysis, and materials technology. (LEW)

  16. Antimicrobial activity of plant essential oils against bacterial and fungal species involved in food poisoning and/or food decay.

    Science.gov (United States)

    Lixandru, Brînduşa-Elena; Drăcea, Nicoleta Olguţa; Dragomirescu, Cristiana Cerasella; Drăgulescu, Elena Carmina; Coldea, Ileana Luminiţa; Anton, Liliana; Dobre, Elena; Rovinaru, Camelia; Codiţă, Irina

    2010-01-01

    The currative properties of aromatic and medicinal plants have been recognized since ancient times and, more recently, the antimicrobial activity of plant essential oils has been used in several applications, including food preservation. The purpose of this study was to create directly comparable, quantitative data on the antimicrobial activity of some plant essential oils prepared in the National Institute of Research-Development for Chemistry and Petrochemistry, Bucharest to be used for the further development of food packaging technology, based on their antibacterial and antifungal activity. The essential oils extracted from thyme (Thymus vulgaris L.), basil (Ocimum basilicum L.), coriander (Coriandrum sativum L.), rosemary (Rosmarinus officinalis L.), sage (Salvia officinalis L.), fennel (Foeniculum vulgare L.), spearmint (Mentha spicata L.) and carraway (Carum carvi L.) were investigated for their antimicrobial activity against eleven different bacterial and three fungal strains belonging to species reported to be involved in food poisoning and/or food decay: S. aureus ATCC 25923, S. aureus ATCC 6538, S. aureus ATCC 25913, E. coli ATCC 25922, E. coli ATCC 35218, Salmonella enterica serovar Enteritidis Cantacuzino Institute Culture Collection (CICC) 10878, Listeria monocytogenes ATCC 19112, Bacillus cereus CIP 5127, Bacillus cereus ATCC 11778, Candida albicans ATCC 10231, Aspergillus niger ATCC 16404, Penicillium spp. CICC 251 and two E. coli and Salmonella enterica serovar Enteritidis clinical isolates. The majority of the tested essential oils exibited considerable inhibitory capacity against all the organisms tested, as supported by growth inhibition zone diameters, MICs and MBC's. Thyme, coriander and basil oils proved the best antibacterial activity, while thyme and spearmint oils better inhibited the fungal species. PMID:21462837

  17. Expression profile of heat shock response factors during hookworm larval activation and parasitic development.

    Science.gov (United States)

    Gelmedin, Verena; Delaney, Angela; Jennelle, Lucas; Hawdon, John M

    2015-07-01

    When organisms are exposed to an increase in temperature, they undergo a heat shock response (HSR) regulated by the transcription factor heat shock factor 1 (HSF-1). The heat shock response includes the rapid changes in gene expression initiated by binding of HSF-1 to response elements in the promoters of heat shock genes. Heat shock proteins function as molecular chaperones to protect proteins during periods of elevated temperature and other stress. During infection, hookworm infective third stage larvae (L3) undergo a temperature shift from ambient to host temperature. This increased temperature is required for the resumption of feeding and activation of L3, but whether this increase initiates a heat shock response is unknown. To investigate the role of the heat shock in hookworm L3 activation and parasitic development, we identified and characterized the expression profile of several components of the heat shock response in the hookworm Ancylostoma caninum. We cloned DNAs encoding an hsp70 family member (Aca-hsp-1) and an hsp90 family member (Aca-daf-21). Exposure to a heat shock of 42°C for one hour caused significant up-regulation of both genes, which slowly returned to near baseline levels following one hour attenuation at 22°C. Neither gene was up-regulated in response to host temperature (37°C). Conversely, levels of hsf-1 remained unchanged during heat shock, but increased in response to incubation at 37°C. During activation, both hsp-1 and daf-21 are down regulated early, although daf-21 levels increase significantly in non-activated control larvae after 12h, and slightly in activated larvae by 24h incubation. The heat shock response modulators celastrol and KNK437 were tested for their effects on gene expression during heat shock and activation. Pre-incubation with celastrol, an HSP90 inhibitor that promotes heat shock gene expression, slightly up-regulated expression of both hsp-1 and daf-21 during heat shock. KNK437, an inhibitor of heat shock

  18. Active solar heating system performance and data review

    Energy Technology Data Exchange (ETDEWEB)

    Bates, J.; Bertarelli, L.; Schmidt, G.

    1999-07-01

    This report summarises the results of a study investigating the performance and costs of solar heating systems in Europe, and their relevance to systems in the UK. Details are given of the identification and review of the available data, the collection of information on UK and overseas systems, and the assessment and analysis of the data. Appendices give a lists of the monitored parameters, European contacts, data sources, the questionnaire for gathering information, and a printout of the data files. (uk)

  19. Status report on preliminary design activities for solar heating and cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    1978-05-01

    Information presented provides status and progress on the development of solar heating and cooling systems. The major emphasis is placed on program organization, system size definition, site identification, system approaches, heat pump and equipment design, collector procurement, and other preliminary design activities as part of the contract requirements.

  20. BRF1 Protein Turnover and mRNA Decay Activity Are Regulated by Protein Kinase B at the Same Phosphorylation Sites▿

    OpenAIRE

    Benjamin, Don; Schmidlin, Martin; Min, Lu; Gross, Brigitte; Moroni, Christoph

    2006-01-01

    BRF1 posttranscriptionally regulates mRNA levels by targeting ARE-bearing transcripts to the decay machinery. We previously showed that protein kinase B (PKB) phosphorylates BRF1 at Ser92, resulting in binding to 14-3-3 and impairment of mRNA decay activity. Here we identify an additional regulatory site at Ser203 that cooperates in vivo with Ser92. In vitro kinase labeling and wortmannin sensitivity indicate that Ser203 phosphorylation is also performed by PKB. Mutation of both serines to al...

  1. Proton Decay

    OpenAIRE

    Raby, Stuart

    2002-01-01

    We discuss the status of supersymmetric grand unified theories [SUSY GUTs] with regards to the observation of proton decay. In this talk we focus on SUSY GUTs in 4 dimensions. We outline the major theoretical uncertainties present in the calculation of the proton lifetime and then present our best estimate of an absolute upper bound on the predicted proton lifetime. Towards the end, we consider some new results in higher dimensional GUTs and the ramifications for proton decay.

  2. Role of heat shock factor-1 activation in the doxorubicin-induced heart failure in mice

    OpenAIRE

    Vedam, Kaushik; Nishijima, Yoshinori; Druhan, Lawrence J.; Khan, Mahmood; Moldovan, Nicanor I.; Zweier, Jay L.; Ilangovan, Govindasamy

    2010-01-01

    Treating cancer patients with chemotherapeutics, such as doxorubicin (Dox), cause dilated cardiomyopathy and congestive heart failure because of oxidative stress. On the other hand, heat shock factor-1 (HSF-1), a transcription factor for heat shock proteins (Hsps), is also known to be activated in response to oxidative stress. However, the possible role of HSF-1 activation and the resultant Hsp25 in chemotherapeutic-induced heart failure has not been investigated. Using HSF-1 wild-type (HSF-1...

  3. Ethnic differences in thermoregulatory responses during resting, passive and active heating: application of Werner's adaptation model.

    Science.gov (United States)

    Lee, Joo-Young; Wakabayashi, Hitoshi; Wijayanto, Titis; Hashiguchi, Nobuko; Saat, Mohamed; Tochihara, Yutaka

    2011-12-01

    For the coherent understanding of heat acclimatization in tropical natives, we compared ethnic differences between tropical and temperate natives during resting, passive and active heating conditions. Experimental protocols included: (1) a resting condition (an air temperature of 28°C with 50% RH), (2) a passive heating condition (28°C with 50% RH; leg immersion in a hot tub at a water temperature of 42°C), and (3) an active heating condition (32°C with 70% RH; a bicycle exercise). Morphologically and physically matched tropical natives (ten Malaysian males, MY) and temperate natives (ten Japanese males, JP) participated in all three trials. The results saw that: tropical natives had a higher resting rectal temperature and lower hand and foot temperatures at rest, smaller rise of rectal temperature and greater temperature rise in bodily extremities, and a lower sensation of thirst during passive and active heating than the matched temperate natives. It is suggested that tropical natives' homeostasis during heating is effectively controlled with the improved stability in internal body temperature and the increased capability of vascular circulation in extremities, with a lower thirst sensation. The enhanced stability of internal body temperature and the extended thermoregulatory capability of vascular circulation in the extremities of tropical natives can be interpreted as an interactive change to accomplish a thermal dynamic equilibrium in hot environments. These heat adaptive traits were explained by Wilder's law of initial value and Werner's process and controller adaptation model.

  4. Monster Sawtooth Activity in Ohmically Heated HT-7 Plasma

    Institute of Scientific and Technical Information of China (English)

    胡立群; 石跃江; 刘胜侠

    2001-01-01

    Experimental properties of monster sawtooth activities in ohmic HT-7 plasma are presented in this paper. The monster sawtooth activities belong to global fluctuations and are characterized with a series of large core collapses on SXR intensity traces with a long period, a large amplitude fluctuation and a large inversion radius. However, they emerge without apparent deterioration of plasma confinement and without major plasma disruption. During the events,long partial sawtooth collapses and abundant MHD phenomena are also observed.

  5. B decays

    CERN Document Server

    Stone, Sheldon

    1992-01-01

    The study of b quarks has now reached a stage where it is useful to review what has been learned so far and also to look at the implications of future studies. The most important observations thus far - measurement of the "B" lifetime, B 0 - B 0 mixing, and the observation of b? u transitions, as well as more mundane results on hadronic and semileptonic transitions - are described in detail by experimentalists who have been closely involved with the measurements. Theoretical progress in understanding b quark decays, including the mechanisms of hadronic and semileptonic decays, are described. S

  6. Optimizing VANDLE for Decay Spectroscopy

    Science.gov (United States)

    Brewer, N. T.; Taylor, S. Z.; Grzywacz, R.; Madurga, M.; Paulauskas, S. V.; Cizewski, J. A.; Peters, W. A.; Vandle Collaboration

    2013-10-01

    Understanding the decay properties of neutron rich isotopes has well established importance to the path of the r-process and to the total decay heat for reactor physics. Specifically, the half-life, branching ratio and spectra for β-n decay is of particular interest. With that in mind, we have continued attempts to improve upon the Versatile Array of Neutron Detectors at Low Energy (VANDLE) in terms of efficiency and TOF resolution through the use of new and larger scintillators. Details of the new implementation, design and characterization of the array will be shown and compared to previous results.

  7. An artificial HSE promoter for efficient and selective detection of heat shock pathway activity.

    Science.gov (United States)

    Ortner, Viktoria; Ludwig, Alfred; Riegel, Elisabeth; Dunzinger, Sarah; Czerny, Thomas

    2015-03-01

    Detection of cellular stress is of major importance for the survival of cells. During evolution, a network of stress pathways developed, with the heat shock (HS) response playing a major role. The key transcription factor mediating HS signalling activity in mammalian cells is the HS factor HSF1. When activated it binds to the heat shock elements (HSE) in the promoters of target genes like heat shock protein (HSP) genes. They are induced by HSF1 but in addition they integrate multiple signals from different stress pathways. Here, we developed an artificial promoter consisting only of HSEs and therefore selectively reacting to HSF-mediated pathway activation. The promoter is highly inducible but has an extreme low basal level. Direct comparison with the HSPA1A promoter activity indicates that heat-dependent expression can be fully recapitulated by isolated HSEs in human cells. Using this sensitive reporter, we measured the HS response for different temperatures and exposure times. In particular, long heat induction times of 1 or 2 h were compared with short heat durations down to 1 min, conditions typical for burn injuries. We found similar responses to both long and short heat durations but at completely different temperatures. Exposure times of 2 h result in pathway activation at 41 to 44 °C, whereas heat pulses of 1 min lead to a maximum HS response between 47 and 50 °C. The results suggest that the HS response is initiated by a combination of temperature and exposure time but not by a certain threshold temperature.

  8. A novel heat flux study of a geothermally active lake - Lake Rotomahana, New Zealand

    Science.gov (United States)

    Tivey, Maurice A.; de Ronde, Cornel E. J.; Tontini, Fabio Caratori; Walker, Sharon L.; Fornari, Daniel J.

    2016-03-01

    A new technique for measuring conductive heat flux in a lake was adapted from the marine environment to allow for multiple measurements to be made in areas where bottom sediment cover is sparse, or even absent. This thermal blanket technique, pioneered in the deep ocean for use in volcanic mid-ocean rift environments, was recently used in the geothermally active Lake Rotomahana, New Zealand. Heat flow from the lake floor propagates into the 0.5 m diameter blanket and establishes a thermal gradient across the known blanket thickness and thereby provides an estimate of the conductive heat flux of the underlying terrain. This approach allows conductive heat flux to be measured over a spatially dense set of stations in a relatively short period of time. We used 10 blankets and deployed them for 1 day each to complete 110 stations over an 11-day program in the 6 × 3 km lake. Results show that Lake Rotomahana has a total conductive heat flux of about 47 MW averaging 6 W/m2 over the geothermally active lake. The western half of the lake has two main areas of high heat flux; 1) a high heat flux area averaging 21.3 W/m2 along the western shoreline, which is likely the location of the pre-existing geothermal system that fed the famous Pink Terraces, mostly destroyed during the 1886 eruption 2) a region southwest of Patiti Island with a heat flux averaging 13.1 W/m2 that appears to be related to the explosive rift that formed the lake in the 1886 Tarawera eruption. A small rise in bottom water temperature over the survey period of 0.01 °C/day suggests the total thermal output of the lake is ~ 112-132 MW and when compared to the conductive heat output suggests that 18-42% of the total thermal energy is by conductive heat transfer.

  9. Influence of heat treatment of rayon-based activated carbon fibers on the adsorption of formaldehyde.

    Science.gov (United States)

    Rong, Haiqin; Ryu, Zhenyu; Zheng, Jingtang; Zhang, Yuanli

    2003-05-15

    The influence of heat treatment of rayon-based activated carbon fibers on the adsorption behavior of formaldehyde was studied. Heat treatment in an inert atmosphere of nitrogen for rayon-based activated carbon fibers (ACFs) resulted in a significant increase in the adsorption capacities and prolongation of breakthrough time on removing of formaldehyde. The effect of different heat-treatment conditions on the adsorption characteristics was investigated. The porous structure parameters of the samples under study were investigated using nitrogen adsorption at the low temperature 77.4 K. The pore size distributions of the samples under study were calculated by density functional theory. With the aid of these analyses, the relationship between structure and adsorption properties of rayon-based ACFs for removing formaldehyde was revealed. Improvement of their performance in terms of adsorption selectivity and adsorption rate for formaldehyde were achieved by heat post-treatment in an inert atmosphere of nitrogen.

  10. Effects of calmodulin on DNA-binding activity of heat shock transcription factor in vitro

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The DNA-binding activity of heat shock transcription factor (HSF) was induced by heat shock (HS) of a whole cell extract. Addition of antiserum, specific to CaM, to a whole cell extract reduced bind of the HSF to the heat shock element (HSE) with maize, and the re-addition of CaM to the sample restored the activity of the HSF for binding to HSE. In addition, DNA-binding activity of the HSF was also induced by directly adding CaM to a whole cell extract at non-HS temperature with maize. Similar results were obtained with wheat and tomato. Our observations provide the first example of the involvement of CaM in regulation of the DNA-binding activity of the HSF.

  11. Procedure of Active Residual Heat Removal after Emergency Shutdown of High-Temperature-Gas-Cooled Reactor

    OpenAIRE

    Xingtuan Yang; Yanfei Sun; Huaiming Ju; Shengyao Jiang

    2014-01-01

    After emergency shutdown of high-temperature-gas-cooled reactor, the residual heat of the reactor core should be removed. As the natural circulation process spends too long period of time to be utilized, an active residual heat removal procedure is needed, which makes use of steam generator and start-up loop. During this procedure, the structure of steam generator may suffer cold/heat shock because of the sudden load of coolant or hot helium at the first few minutes. Transient analysis was ca...

  12. A JOULE-HEATED MELTER TECHNOLOGY FOR THE TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE

    Energy Technology Data Exchange (ETDEWEB)

    KELLY SE

    2011-04-07

    This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of joule-heated ceramic lined melters and their application to Hanford's low-activity waste.

  13. Development of analysis code of immersed decay heat removal system for fast reactor%快堆浸入式事故余热排出系统程序开发

    Institute of Scientific and Technical Information of China (English)

    钱鸿涛; 李政昕; 胡文军; 宫宇

    2015-01-01

    To meet the need of demonstration fast reactor design,a thermal-hydraulic analysis code of immersed decay heat remov-al system was developed based on a French fast reactor system code OASIS,with the introduction of the thermal stratification and inter-wrapper flow models.An integrated model was developed for the decay heat removal system of CEFR using the code,and the performances at steady and transient station black-out were analyzed.The calculation results were validated with other codes.%针对示范快堆的设计需要,在法国快堆系统程序 OASIS 的基础上,引入热分层与盒间流模型,开发了浸入式事故余热排出系统分析程序。利用该程序对 CEFR 的非能动事故余热排出系统进行了整体建模,分析了稳态和全厂断电工况下的性能,并利用其他系统程序的结果进行了验证。结果表明:该程序能较好地反映事故余热排出系统的瞬态变化过程。

  14. How a retrotransposon exploits the plant's heat stress response for its activation.

    Directory of Open Access Journals (Sweden)

    Vladimir V Cavrak

    2014-01-01

    Full Text Available Retrotransposons are major components of plant and animal genomes. They amplify by reverse transcription and reintegration into the host genome but their activity is usually epigenetically silenced. In plants, genomic copies of retrotransposons are typically associated with repressive chromatin modifications installed and maintained by RNA-directed DNA methylation. To escape this tight control, retrotransposons employ various strategies to avoid epigenetic silencing. Here we describe the mechanism developed by ONSEN, an LTR-copia type retrotransposon in Arabidopsis thaliana. ONSEN has acquired a heat-responsive element recognized by plant-derived heat stress defense factors, resulting in transcription and production of full length extrachromosomal DNA under elevated temperatures. Further, the ONSEN promoter is free of CG and CHG sites, and the reduction of DNA methylation at the CHH sites is not sufficient to activate the element. Since dividing cells have a more pronounced heat response, the extrachromosomal ONSEN DNA, capable of reintegrating into the genome, accumulates preferentially in the meristematic tissue of the shoot. The recruitment of a major plant heat shock transcription factor in periods of heat stress exploits the plant's heat stress response to achieve the transposon's activation, making it impossible for the host to respond appropriately to stress without losing control over the invader.

  15. Effects of microwave heating on porous structure of regenerated powdered activated carbon used in xylose.

    Science.gov (United States)

    Li, Wei; Wang, Xinying; Peng, Jinhui

    2014-01-01

    The regeneration of spent powdered activated carbons used in xylose decolourization by microwave heating was investigated. Effects of microwave power and microwave heating time on the adsorption capacity of regenerated activated carbons were evaluated. The optimum conditions obtained are as follows: microwave power 800W; microwave heating time 30min. Regenerated activated carbon in this work has high adsorption capacities for the amount of methylene blue of 16 cm3/0.1 g and the iodine number of 1000.06mg/g. The specific surface areas of fresh commercial activated carbon, spent carbon and regenerated activated carbon were calculated according to the Brunauer, Emmett and Teller method, and the pore-size distributions of these carbons were characterized by non-local density functional theory (NLDFT). The results show that the specific surface area and the total pore volume of regenerated activated carbon are 1064 m2/g and 1.181 mL/g, respectively, indicating the feasibility of regeneration of spent powdered activated carbon used in xylose decolourization by microwave heating. The results of surface fractal dimensions also confirm the results of isotherms and NLDFT. PMID:24645431

  16. Effects of microwave heating on porous structure of regenerated powdered activated carbon used in xylose.

    Science.gov (United States)

    Li, Wei; Wang, Xinying; Peng, Jinhui

    2014-01-01

    The regeneration of spent powdered activated carbons used in xylose decolourization by microwave heating was investigated. Effects of microwave power and microwave heating time on the adsorption capacity of regenerated activated carbons were evaluated. The optimum conditions obtained are as follows: microwave power 800W; microwave heating time 30min. Regenerated activated carbon in this work has high adsorption capacities for the amount of methylene blue of 16 cm3/0.1 g and the iodine number of 1000.06mg/g. The specific surface areas of fresh commercial activated carbon, spent carbon and regenerated activated carbon were calculated according to the Brunauer, Emmett and Teller method, and the pore-size distributions of these carbons were characterized by non-local density functional theory (NLDFT). The results show that the specific surface area and the total pore volume of regenerated activated carbon are 1064 m2/g and 1.181 mL/g, respectively, indicating the feasibility of regeneration of spent powdered activated carbon used in xylose decolourization by microwave heating. The results of surface fractal dimensions also confirm the results of isotherms and NLDFT.

  17. Evidence of Impulsive Heating in Active Region Core Loops

    CERN Document Server

    Tripathi, Durgesh; Klimchuk, James A

    2010-01-01

    Using a full spectral scan of an active region from the Extreme-Ultraviolet Imaging Spectrometer (EIS) we have obtained Emission Measure EM$(T)$ distributions in two different moss regions within the same active region. We have compared these with theoretical transition region EMs derived for three limiting cases, namely \\textit{static equilibrium}, \\textit{strong condensation} and \\textit{strong evaporation} from \\cite{ebtel}. The EM distributions in both the moss regions are strikingly similar and show a monotonically increasing trend from $\\log T[\\mathrm{K}]=5.15 -6.3$. Using photospheric abundances we obtain a consistent EM distribution for all ions. Comparing the observed and theoretical EM distributions, we find that the observed EM distribution is best explained by the \\textit{strong condensation} case (EM$_{con}$), suggesting that a downward enthalpy flux plays an important and possibly dominant role in powering the transition region moss emission. The downflows could be due to unresolved coronal plas...

  18. A correction factor to f-chart predictions of active solar fraction in active-passive heating systems

    Science.gov (United States)

    Evans, B. L.; Beckman, W. A.; Duffie, J. A.; Mitchell, J. W.; Klein, S. A.

    1983-11-01

    The extent to which a passive system degrades the performance of an active solar space heating system was investigated, and a correction factor to account for these interactions was developed. The transient system simulation program TRNSYS is used to simulate the hour-by-hour performance of combined active-passive (hybrid) space heating systems in order to compare the active system performance with simplified design method predictions. The TRNSYS simulations were compared to results obtained using the simplified design calculations of the f-Chart method. Comparisons of TRNSYS and f-Chart were used to establish the accuracy of the f-Charts for active systems. A correlation was then developed to correct the monthly loads input into the f-Chart method to account for controller deadbands in both hybrid and active only buildings. A general correction factor was generated to be applied to the f-Chart method to produce more accurate and useful results for hybrid systems.

  19. On the relationship between photospheric footpoint motions and coronal heating in solar active regions

    International Nuclear Information System (INIS)

    Coronal heating theories can be classified as either direct current (DC) or alternating current (AC) mechanisms, depending on whether the coronal magnetic field responds quasi-statically or dynamically to the photospheric footpoint motions. In this paper we investigate whether photospheric footpoint motions with velocities of 1-2 km s–1 can heat the corona in active regions, and whether the corona responds quasi-statically or dynamically to such motions (DC versus AC heating). We construct three-dimensional magnetohydrodynamic models for the Alfvén waves and quasi-static perturbations generated within a coronal loop. We find that in models where the effects of the lower atmosphere are neglected, the corona responds quasi-statically to the footpoint motions (DC heating), but the energy flux into the corona is too low compared to observational requirements. In more realistic models that include the lower atmosphere, the corona responds more dynamically to the footpoint motions (AC heating) and the predicted heating rates due to Alfvén wave turbulence are sufficient to explain the observed hot loops. The higher heating rates are due to the amplification of Alfvén waves in the lower atmosphere. We conclude that magnetic braiding is a highly dynamic process.

  20. Pulsed nanosecond discharge in air at high specific deposited energy: fast gas heating and active particle production

    Science.gov (United States)

    Popov, N. A.

    2016-08-01

    The results of a numerical study on kinetic processes initiated by a pulsed nanosecond discharge in air at high specific deposited energy, when the dissociation degree of oxygen molecules is high, are presented. The calculations of the temporal dynamics of the electron concentration, density of atomic oxygen, vibrational distribution function of nitrogen molecules, and gas temperature agree with the experimental data. It is shown that quenching of electronically excited states of nitrogen N2(B3Πg), N2(C3Πu), N2(a‧1 Σ \\text{u}- ) by oxygen molecules leads to the dissociation of O2. This conclusion is based on the comparison of calculated dynamics of atomic oxygen in air, excited by a pulsed nanosecond discharge, with experimental data. In air plasma at a high dissociation degree of oxygen molecules ([O]/[O2] > 10%), relaxation of the electronic energy of atoms and molecules in reactions with O atoms becomes extremely important. Active production of NO molecules and fast gas heating in the discharge plasma due to the quenching of electronically excited N2(B3Πg, C3Πu, a‧1 Σ \\text{u}- ) molecules by oxygen atoms is notable. Owing to the high O atom density, electrons are effectively detached from negative ions in the discharge afterglow. As a result, the decay of plasma in the afterglow is determined by electron-ion recombination, and the electron density remains relatively high between the pulses. An increase in the vibrational temperature of nitrogen molecules at the periphery of the plasma channel at time delay t = 1-30 μs after the discharge is obtained. This is due to intense gas heating and, as a result, gas-dynamic expansion of a hot gas channel. Vibrationally excited N2(v) molecules produced near the discharge axis move from the axial region to the periphery. Consequently, at the periphery the vibrational temperature of nitrogen molecules is increased.

  1. Isosteric heats of adsorption for activated carbons made from corn cob

    Science.gov (United States)

    Beckner, M.; Olsen, R.; Romanos, J.; Burress, J.; Dohnke, E.; Carter, S.; Casteel, G.; Wexler, C.; Pfeifer, P.

    2010-03-01

    Activated carbons made from corn cob show promise as materials for high-capacity hydrogen storage. As part of our characterization of these materials, we are interested in learning how different production methods affect the adsorption energies. In this talk, we will present experimentally measured isosteric heats of adsorption for various activated carbons calculated using the Clausius-Clayperon equation and hydrogen isotherms at temperatures of 80 and 90K and pressures up to 100 bar measured on a volumetric instrument. We discuss differences observed between isosteric heats determined from Gibbs excess adsorption vs. absolute adsorption curves.

  2. Effect of heat treatment on anodic activation of aluminium by trace element indium

    Energy Technology Data Exchange (ETDEWEB)

    Graver, Brit [Department of Materials Science and Engineering, Norwegian University of Science and Technology, N-7491 Trondheim (Norway); Helvoort, Antonius T.J. van [Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim (Norway); Nisancioglu, Kemal, E-mail: kemal.nisancioglu@material.ntnu.n [Department of Materials Science and Engineering, Norwegian University of Science and Technology, N-7491 Trondheim (Norway)

    2010-11-15

    Research highlights: {yields} Indium segregation activates AlIn alloy surface anodically in chloride solution. {yields} Enrichment of In on Al surface can occur thermally by heat treatment at 300 {sup o}C. {yields} Increasing temperature homogenises indium in aluminium reducing anodic activation. {yields} Indium can activate AlIn surface by segregating through dealloying of aluminium. {yields} Anodic activation is caused by AlIn amalgam formation at aluminium surface. - Abstract: The presence of trace elements in Group IIIA-VA is known to activate aluminium anodically in chloride environment. The purpose of this paper is to investigate the surface segregation of trace element In by heat treatment and resulting surface activation. Model binary AlIn alloys, containing 20 and 1000 ppm by weight of In, were characterized after heat treatment at various temperatures by use of glow discharge optical emission spectroscopy, electron microscopy and electrochemical polarization. Heat treatment for 1 h at 300 {sup o}C gave significant segregation of discrete In particles (thermal segregation), which activated the surface. Indium in solid solution with aluminium, obtained by 1 h heat treatment at 600 {sup o}C, also activated by surface segregation of In on alloy containing 1000 ppm In, resulting from the selective dissolution of the aluminium component during anodic oxidation (anodic segregation). The effect of anodic segregation was reduced by decreasing indium concentration in solid solution; it had negligible effect at the 20 ppm level. The segregated particles were thought to form a liquid phase alloy with aluminium during anodic polarization, which in turn, together with the chloride in the solution destabilized the oxide.

  3. Leishmania amazonensis: effects of heat shock on ecto-ATPase activity.

    Science.gov (United States)

    Peres-Sampaio, Carlos Eduardo; de Almeida-Amaral, Elmo Eduardo; Giarola, Naira Ligia Lima; Meyer-Fernandes, José Roberto

    2008-05-01

    In this work we demonstrated that promastigotes of Leishmania amazonensis exhibit an Mg-dependent ecto-ATPase activity, which is stimulated by heat shock. The Mg-dependent ATPase activity of cells grown at 22 and 28 degrees C was 41.0+/-5.2 nmol Pi/h x 10(7)cells and 184.2+/-21.0 nmol Pi/h x 10(7)cells, respectively. When both promastigotes were pre-incubated at 37 degrees C for 2h, the ATPase activity of cells grown at 22 degrees C was increased to 136.4+/-10.6 nmol Pi/h x 10(7) whereas that the ATPase activity of cells grown at 28 degrees C was not modified by the heat shock (189.8+/-10.3 nmol Pi/h x 10(7)cells). It was observed that Km of the enzyme from cells grown at 22 degrees C (Km=980.2+/-88.6 microM) was the same to the enzyme from cells grown at 28 degrees C (Km=901.4+/-91.9 microM). In addition, DIDS (4,4'-diisothiocyanatostilbene 2,2'-disulfonic acid) and suramin, two inhibitors of ecto-ATPases, also inhibited similarly the ATPase activities from promastigotes grown at 22 and 28 degrees C. We also observed that cells grown at 22 degrees C exhibit the same ecto-phosphatase and ecto 3'- and 5'-nucleotidase activities than cells grown at 28 degrees C. Interestingly, cycloheximide, an inhibitor of protein synthesis, suppressed the heat-shock effect on ecto-ATPase activity of cells grown at 22 degrees C were exposed at 37 degrees C for 2h. A comparison between the stimulation of the Mg-dependent ecto-ATPase activity of virulent and avirulent promastigotes by the heat shock showed that avirulent promastigotes had a higher stimulation than virulent promastigotes after heat stress. PMID:18295760

  4. "Hot" Non-flaring Plasmas in Active Region Cores Heated by Single Nanoflares

    Science.gov (United States)

    Barnes, Will Thomas; Cargill, Peter; Bradshaw, Stephen

    2016-05-01

    We use hydrodynamic modeling tools, including a two-fluid development of the EBTEL code, to investigate the properties expected of "hot" (i.e. between 106.7 and 107.2 K) non-flaring plasmas due to nanoflare heating in active regions. Here we focus on single nanoflares and show that while simple models predict an emission measure distribution extending well above 10 MK that is consistent with cooling by thermal conduction, many other effects are likely to limit the existence and detectability of such plasmas. These include: differential heating between electrons and ions, ionization non-equilibrium and, for short nanoflares, the time taken for the coronal density to increase. The most useful temperature range to look for this plasma, often called the "smoking gun" of nanoflare heating, lies between 1 MK and 10 MK. Signatures of the actual heating may be detectable in some instances.

  5. Structural and preliminary thermal performance testing of a pressure activated contact heat exchanger

    Science.gov (United States)

    Lee, C. Y.; Christian, E. L.; Wohlwend, J. W.; Parish, R. C.

    1987-01-01

    A contact heat exchanger concept is being developed for use onboard Space Station as an interface device between external thermal bus and pressurized modules. The concept relies on mechanical contact activated by the fluid pressure inside thin-walled tubes. Structural testings were carried out to confirm the technology feasibility of using such thin-walled tubes. The test results also verified the linear elastic stress analysis which was used to predict the tube mechanical behaviors. A preliminary thermal testing was also performed with liquid Freon-11 flowing inside tubes and heat being supplied by electrical heating from the bottom of the contact heat exchanger baseplate. The test results showed excellent agreement of test data with analytical prediction for all thermal resistances except for the two-phase flow characteristics. Testing with two-phase flow inside tubes will, however, be performed on the NASA-JSC test bed.

  6. Improvement of the decay heat removal characteristics of the generation IV gas-cooled fast reactor; Amelioration des caracteristiques de la dissipation de la chaleur de decroissance pour les reacteurs a neutrons rapides de quatrieme generation refroidi au gaz

    Energy Technology Data Exchange (ETDEWEB)

    Epiney, A.S.

    2010-09-07

    The main drawback of the GFR is the difficulty to evacuate decay heat following a loss-of-coolant accident (LOCA) due to the low thermal inertia of the core, as well as to the low coolant density. The present doctoral research focuses on the improvement of decay heat removal (DHR) for the Generation-IV GFR. The reference GFR system design considered in the thesis is the 2006 CEA concept, with a power of 2400 MWth. The CEA 2006 DHR strategy foresees, in all accidental cases (independent of the system pressure), that the reactor is shut down. For high pressure events, dedicated DHR loops with blowers and heat exchangers are designed to operate when the power conversion system cannot be used to provide acceptable core temperatures under natural convection conditions. For de-pressurized events, the strategy relies on a dedicated small containment (called the guard containment) providing an intermediate back-up pressure. The DHR blowers, designed to work under these pressure conditions, need to be powered either by the power grid or by batteries for at least 24 hours. The specific contributions of the present research - aimed at achieving enhanced passivity of the DHR system for the GFR - are design and analysis related to (1) the injection of heavy gas into the primary circuit after a LOCA, to enable natural convection cooling at an intermediate-pressure level, and (2) an autonomous Brayton loop to evacuate decay heat at low primary pressure in case of a loss of the guard containment pressure. Both these developments reduce the dependence on blower power availability considerably. First, the thermal-hydraulic codes used in the study - TRACE and CATHARE - are validated for gas cooling. The validation includes benchmark comparisons between the codes, serving to identify the sensitivity of the results to the different modeling assumptions. The parameters found to be the most sensitive in this analysis, such as heat transfer and friction models, are then validated via a

  7. Active Power Flow Optimization of Industrial Power Supply with Regard to the Transmission Line Conductor Heating

    Directory of Open Access Journals (Sweden)

    Leyzgold D.Yu.

    2015-04-01

    Full Text Available This article studies the problem of the transmission line conductor heating effect on the active power flows optimization in the local segment of industrial power supply. The purpose is to determine the optimal generation rating of the distributed power sources, in which the power flow values will correspond to the minimum active power losses in the power supply. The timeliness is the need to define the most appropriate rated power values of distributed sources which will be connected to current industrial power supply. Basing on the model of active power flow optimization, authors formulate the description of the nonlinear transportation problem considering the active power losses depending on the transmission line conductor heating. Authors proposed a new approach to the heating model parameters definition based on allowable current loads and nominal parameters of conductors as part of the optimization problem. Analysis of study results showed that, despite the relatively small active power losses reduction to the tune 0,45% due to accounting of the conductors heating effect for the present configuration of power supply, there are significant fluctuations in the required generation rating in nodes of the network to 9,32% within seasonal changes in the outer air temperature. This fact should be taken into account when selecting the optimum power of distributed generation systems, as exemplified by an arbitrary network configuration.

  8. Innovative two-pipe active chilled beam system for simultaneous heating and cooling of office buildings

    DEFF Research Database (Denmark)

    Maccarini, Alessandro; Afshari, Alireza; Bergsøe, Niels Christian;

    2014-01-01

    energy between zones with one hydronic circuit, operating with a water temperature between 20°C and 23°C. To calculate the energy performance of the system, simulation-based research was developed. The two-pipe system was modelled by using EnergyPlus, a whole building energy simulation program. Hourly......The aim of this paper was to investigate the energy savings potential of an innovative two-pipe system in an active chilled beam application for heating and cooling of office buildings. The characteristic of the system is its ability to provide simultaneous heating and cooling by transferring...... heating, cooling and ventilation loads were calculated by the program and an annual energy consumption evaluation of the system was made. Simulation results showed that the innovative two-pipe active chilled beam system used approximately 5% less energy than a conventional four-pipe system....

  9. Compound A, a selective glucocorticoid receptor modulator, enhances heat shock protein Hsp70 gene promoter activation.

    Directory of Open Access Journals (Sweden)

    Ilse M Beck

    Full Text Available Compound A possesses glucocorticoid receptor (GR-dependent anti-inflammatory properties. Just like classical GR ligands, Compound A can repress NF-κB-mediated gene expression. However, the monomeric Compound A-activated GR is unable to trigger glucocorticoid response element-regulated gene expression. The heat shock response potently activates heat shock factor 1 (HSF1, upregulates Hsp70, a known GR chaperone, and also modulates various aspects of inflammation. We found that the selective GR modulator Compound A and heat shock trigger similar cellular effects in A549 lung epithelial cells. With regard to their anti-inflammatory mechanism, heat shock and Compound A are both able to reduce TNF-stimulated IκBα degradation and NF-κB p65 nuclear translocation. We established an interaction between Compound A-activated GR and Hsp70, but remarkably, although the presence of the Hsp70 chaperone as such appears pivotal for the Compound A-mediated inflammatory gene repression, subsequent novel Hsp70 protein synthesis is uncoupled from an observed CpdA-induced Hsp70 mRNA upregulation and hence obsolete in mediating CpdA's anti-inflammatory effect. The lack of a Compound A-induced increase in Hsp70 protein levels in A549 cells is not mediated by a rapid proteasomal degradation of Hsp70 or by a Compound A-induced general block on translation. Similar to heat shock, Compound A can upregulate transcription of Hsp70 genes in various cell lines and BALB/c mice. Interestingly, whereas Compound A-dependent Hsp70 promoter activation is GR-dependent but HSF1-independent, heat shock-induced Hsp70 expression alternatively occurs in a GR-independent and HSF1-dependent manner in A549 lung epithelial cells.

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

    Science.gov (United States)

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

    2015-06-01

    Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperature-humidity index (THI) is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is difficult to ascertain whether THI is the most appropriate measurement of heat stress in dairy cows. This experiment was conducted to investigate the effects of heat stress on serum insulin, adipokines (leptin and adiponectin), AMP-activated protein kinase (AMPK), and heat shock signal molecules (heat shock transcription factor (HSF) and heat shock proteins (HSP)) in dairy cows and to research biomarkers to be used for better understanding the meaning of THI as a bioclimatic index. To achieve these objectives, two experiments were performed. The first experiment: eighteen lactating Holstein dairy cows were used. The treatments were: heat stress (HS, THI average=81.7, n=9) and cooling (CL, THI average=53.4, n=9). Samples of HS were obtained on August 16, 2013, and samples of CL were collected on April 7, 2014 in natural conditions. The second experiment: HS treatment cows (n=9) from the first experiment were fed for 8 weeks from August 16, 2013 to October 12, 2013. Samples for moderate heat stress, mild heat stress, and no heat stress were obtained, respectively, according to the physical alterations of the THI. Results showed that heat stress significantly increased the serum adiponectin, AMPK, HSF, HSP27, HSP70, and HSP90 (Pbiomarkers to supplement the THI and evaluate moderate heat stress in dairy cows in the future. PMID:26055916

  11. Thermal activation of OSL as a geothermometer for quartz grain heating during fault movements

    CERN Document Server

    Rink, W J; Rees-Jones, J; Schwarcz, H P

    1999-01-01

    In discussions of ESR dating of fault movements, there has been much debate whether zeroing of ESR signals is a mechanical shearing effect or caused by frictional heating. The OSL (optically stimulated luminescence) sensitivity of quartz is known to increase after heating. This thermal activation of dose response of the OSL in quartz should be useful as a geothermometer to test whether quartz particles in fault gouge had been heated. We tested the OSL sensitivities of quartz from fault gouge, and from a control (quartz grains from sandstone) and were able to show heat-induced enhancement of OSL sensitivity to a test dose. We observed that relative enhancement of OSL dose response (ratio of heated to unheated single aliquots) is significantly less for the finest grains (45-75 and 100-150 mu m) compared with coarser grains (150-250 mu m). These data are consistent with a model of zeroing of the quartz grains during faulting, by frictional heating localized to the grain boundaries, which would be expected to aff...

  12. Management of the endoplasmic reticulum stress by activation of the heat shock response in yeast

    DEFF Research Database (Denmark)

    Hou, Jin; Tang, Hongting; Liu, Zihe;

    2014-01-01

    In yeast Saccharomyces cerevisiae, accumulation of misfolded proteins in the endoplasmic reticulum (ER) causes ER stress and activates the unfolded protein response (UPR), which is mediated by Hac1p. The heat shock response (HSR) mediated by Hsf1p, mainly regulates cytosolic processes and protect...

  13. Experimental investigations of heat transfer in thermo active building systems in combination with suspended ceilings

    DEFF Research Database (Denmark)

    Alvarez, Maria Alonso; Hviid, Christian Anker; Weitzmann, Peter

    2014-01-01

    Thermo Active Building Systems (TABS), described as radiant heating or cooling systems with pipes embedded in the building structure, represent a sustainable alternative to replace conventional systems by using source temperatures close to room temperatures. The use of suspended ceiling in office...

  14. Electric space heating scheduling for real-time explicit power control in active distribution networks

    DEFF Research Database (Denmark)

    Costanzo, Giuseppe Tommaso; Bernstein, Andrey; Chamorro, Lorenzo Reyes;

    2015-01-01

    This paper presents a systematic approach for abstracting the flexibility of a building space heating system and using it within a composable framework for real-time explicit power control of microgrids and, more in general, active distribution networks. In particular, the proposed approach...

  15. Physical Activity in the Heat: Important Considerations to Keep Your Students Safe

    Science.gov (United States)

    Roetert, E. Paul; Richardson, Cheryl L.; Bergeron, Michael F.

    2012-01-01

    Although July and August tend to be the warmest months of the year, the months leading up to summer as well as the months just following summer can also be quite warm or even very hot. In this article, the authors share some important information to help prepare physical educators for overseeing activities in the heat and, just as importantly, to…

  16. Development of JENDL Decay and Fission Yield Data Libraries

    Science.gov (United States)

    Katakura, J.

    2014-04-01

    Decay and fission yield data of fission products have been developed for decay heat calculations to constitute one of the special purpose files of JENDL (Japanese Nuclear Data Library). The decay data in the previous JENDL decay data file have been updated based on the data extracted from ENSDF (Evaluated Nuclear Structure Data File) and those by Total Absorption Gamma-ray Spectroscopy (TAGS) measurements reported recently. Fission yield data have also been updated in order to maintain consistency between the decay and yield data files. Decay heat calculations were performed using the updated decay and yield data, and the results were compared with measured decay heat data to demonstrate their applicability. The uncertainties of the calculated results were obtained by sensitivity analyses. The resulting JENDL calculations and their uncertainty were compared with those from the ENDF and JEFF evaluated files.

  17. JENDL FP decay data file 2000

    Energy Technology Data Exchange (ETDEWEB)

    Katakura, Jun-ichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yoshida, Tadashi [Musashi Inst. of Tech., Tokyo (Japan); Oyamatsu, Kazuhiro [Aichi Shukutoku Univ., Nagakute, Aichi (Japan); Tachibana, Takahiro [Waseda Univ., Tokyo (Japan)

    2001-07-01

    A decay data file of fission product (FP) nuclides has been developed for the use in nuclear technology field as one of special purpose files of JENDL (Japanese Evaluated Nuclear Data Library) in the format of ENDF/B and it is called JENDL FP Decay Data File 2000. The file includes the decay data for 1229 fission product nuclides: 142 stable and 1087 unstable nuclides. The data included for a nuclide are decay modes, their Q values and branching ratios, average decay energy values of beta-rays, gamma-rays and alpha-particles and their spectral data. The primary source of the decay data is ENSDF (Evaluated Nuclear Structure Data File), which is the internationally recognized data file of nuclear structure properties. The data in ENSDF, however, cover only measured ones. The data of the short-lived nuclides needed for the application fields such as decay heat prediction are often incomplete or not measured because of their short half-lives. For such nuclides a theoretical model calculation is applied to derive the needed data such as average decay energies and spectral data. The data in JENDL FP Decay Data File 2000 have been tested by summation calculation comparing its results with measured data of decay heat values and aggregate fission product spectra of various fissioning nuclei. The comparison showed good agreement between the calculated results and the measured values. (author)

  18. Effects of heat processing on soya bean fatty acids content and the lipoxygenase activity

    Directory of Open Access Journals (Sweden)

    Žilić Slađana M.

    2010-01-01

    Full Text Available Effects of increased temperatures on the lipoxygenase activity and changes of soya bean fatty acids were observed in the present study. The kernels of soya bean cultivars Bosa and ZPS 015 were subjected to the treatments of extrusion, autoclaving, micronisation and microwave roasting. Depending on the technological processing procedure, the kernels were exposed to temperatures ranging from 60 to 150°C for 25 to 30 seconds during extrusion and for 30 minutes during autoclaving. The temperature that developed in the course of the microwave radiation and autoclaving did not cause statistically significant differences between oil content in heat treated and fresh kernels of soya bean. However, the oil content was higher in soya bean flakes (micronized kernels and lower in grits than in fresh kernels. The heat treatments resulted in the significant decrease of the linolenic fatty acid content. Depending on the temperature and applied heat treatments, the content of linoleic and oleic fatty acid oscillated. High temperatures caused changes in unsaturated fatty acids with 18 carbon atoms resulting in relative increase of the stearic acid content. The lipoxygenase activity decreased in correlation with increased temperatures and the time of heating. The maximum drop of the activity was observed after kernel exposure to the extrusion and micronisation processes at the temperature of 100oC. However, a significant lipoxygenase activity increase was recorded in both studied cultivars after one-minute microwave heating, i.e. at the temperature about 60°C. A further temperature increase led to a gradual denaturation of the enzyme and therefore to its decreased activity.

  19. Effect of Activation Temperature and Heating Duration on Physical Characteristics of Activated Carbon Prepared from Agriculture Waste

    Directory of Open Access Journals (Sweden)

    Tham Yee Jun

    2010-01-01

    Full Text Available This study was conducted to determine the physical characteristics of activated carbon prepared from durian shell in varied heating durations from 10 min to 30 min and activation temperatures of 400C and 500C. Durian shells have been characterized in term of ultimate and proximate analysis, chemical composition and thermal behaviour with a view to be used as activated carbon precursor. Durian shell activated carbon was prepared by impregnating 10g of sample in 10% (v/v concentration of phosphoric acid for 24 h, followed by carbonization at 400C and 500C with different heating durations under nitrogen atmosphere. The results showed that various treatment conditions affect the percentage of yield, BET surface area, micropore volume, and average pore diameter. The highest surface area (SBET 1024 m2/g was obtained at 500C and 20 min of heating duration with 63% of yield and 0.21 cm3/g micropore volume.

  20. Actively heated high-resolution fiber-optic-distributed temperature sensing to quantify streambed flow dynamics in zones of strong groundwater upwelling

    Science.gov (United States)

    Briggs, Martin A.; Buckley, Sean F.; Bagtzoglou, Amvrossios C.; Werkema, Dale D.; Lane, John W.

    2016-07-01

    Zones of strong groundwater upwelling to streams enhance thermal stability and moderate thermal extremes, which is particularly important to aquatic ecosystems in a warming climate. Passive thermal tracer methods used to quantify vertical upwelling rates rely on downward conduction of surface temperature signals. However, moderate to high groundwater flux rates (>-1.5 m d-1) restrict downward propagation of diurnal temperature signals, and therefore the applicability of several passive thermal methods. Active streambed heating from within high-resolution fiber-optic temperature sensors (A-HRTS) has the potential to define multidimensional fluid-flux patterns below the extinction depth of surface thermal signals, allowing better quantification and separation of local and regional groundwater discharge. To demonstrate this concept, nine A-HRTS were emplaced vertically into the streambed in a grid with ˜0.40 m lateral spacing at a stream with strong upward vertical flux in Mashpee, Massachusetts, USA. Long-term (8-9 h) heating events were performed to confirm the dominance of vertical flow to the 0.6 m depth, well below the extinction of ambient diurnal signals. To quantify vertical flux, short-term heating events (28 min) were performed at each A-HRTS, and heat-pulse decay over vertical profiles was numerically modeled in radial two dimension (2-D) using SUTRA. Modeled flux values are similar to those obtained with seepage meters, Darcy methods, and analytical modeling of shallow diurnal signals. We also observed repeatable differential heating patterns along the length of vertically oriented sensors that may indicate sediment layering and hyporheic exchange superimposed on regional groundwater discharge.

  1. Active charge/passive discharge solar heating systems: Thermal analysis and performance comparisons and performance comparisons

    Science.gov (United States)

    Swisher, J.

    1981-06-01

    This type of system combines liquid-cooled solar collector panels with a massive integral storage component that passively heats the building interior by radiation and free convection. The TRNSYS simulation program is used to evaluate system performance and to provide input for the development of a simplified analysis method. This method, which provides monthly calculations of delivered solar energy, is based on Klein's Phi-bar procedure and data from hourly TRNSYS simulations. The method can be applied to systems using a floor slab, a structural wall, or a water tank as the storage component. Important design parameters include collector area and orientation, building heat loss, collector and heat exchanger efficiencies, storage capacity, and storage to room coupling. Performance simulation results are used for comparisons with active and passive solar designs.

  2. Evaluation of a large capacity heat pump concept for active cooling of hypersonic aircraft structure

    Science.gov (United States)

    Pagel, L. L.; Herring, R. L.

    1978-01-01

    Results of engineering analyses assessing the conceptual feasibility of a large capacity heat pump for enhancing active cooling of hypersonic aircraft structure are presented. A unique heat pump arrangement which permits cooling the structure of a Mach 6 transport to aluminum temperatures without the aid of thermal shielding is described. The selected concept is compatible with the use of conventional refrigerants, with Freon R-11 selected as the preferred refrigerant. Condenser temperatures were limited to levels compatible with the use of conventional refrigerants by incorporating a unique multipass condenser design, which extracts mechanical energy from the hydrogen fuel, prior to each subsequent pass through the condenser. Results show that it is technically feasible to use a large capacity heat pump in lieu of external shielding. Additional analyses are required to optimally apply this concept.

  3. Novel ac Heating-dc Detection Method for Active Thermoelectric Scanning Thermal Microscopy

    Science.gov (United States)

    Miao, Tingting; Ma, Weigang; Zhang, Xing

    2015-11-01

    A novel and reliable ac heating-dc detection method is developed for active thermoelectric scanning thermal microscopy, which can map out local thermal property imaging by point-heating and point-sensing with nanoscale spatial resolution. The thermoelectric probe is electrically heated by an ac current, and the corresponding dc thermoelectric voltage is detected. Using the measured dc voltage, the temperature information can be extracted with the known Seebeck coefficient of the thermoelectric probe. The validity and accuracy of this method have been verified by a 25.4 \\upmu m thick K-type thermocouple by both experiment and numerical simulation in high vacuum and in air. The experimental results show that the proposed method is reliable and convenient to monitor the temperature of the junction.

  4. Linear Active Disturbance Rejection Control of Waste Heat Recovery Systems with Organic Rankine Cycles

    Directory of Open Access Journals (Sweden)

    Fang Fang

    2012-12-01

    Full Text Available In this paper, a linear active disturbance rejection controller is proposed for a waste heat recovery system using an organic Rankine cycle process, whose model is obtained by applying the system identification technique. The disturbances imposed on the waste heat recovery system are estimated through an extended linear state observer and then compensated by a linear feedback control strategy. The proposed control strategy is applied to a 100 kW waste heat recovery system to handle the power demand variations of grid and process disturbances. The effectiveness of this controller is verified via a simulation study, and the results demonstrate that the proposed strategy can provide satisfactory tracking performance and disturbance rejection.

  5. Active compensation of wavefront aberrations by controllable heating of lens with electric film heater matrix.

    Science.gov (United States)

    Chen, Hua; Hou, Lv; Zhou, Xinglin

    2016-08-20

    We present a new apparatus for active compensation of wavefront aberrations by controllable heating of a lens using a film heater matrix. The annular electric film heater matrix, comprising 24 individual heaters, is attached to the periphery of a lens. Utilizing the linear superposition, and wavefront change proportional to the heating energy properties induced by heating, a controllable wavefront can be defined by solving a linear function. The two properties of wavefront change of a lens have been confirmed through a specially designed experiment. The feasibility of the compensation method is validated by compensating the wavefront of a plate lens. The results show that the wavefront of the lens changes from 12.52 to 2.95 nm rms after compensation. With a more precise electric controlling board, better results could be achieved. PMID:27556982

  6. Evaluating the accuracy of the Distributed Activation Energy Model for biomass devolatilization curves obtained at high heating rates

    International Nuclear Information System (INIS)

    Highlights: • DAEM was applied to biomass pyrolysis using a wide range of heating rates. • The validity of the method was evaluated for high heating rates. • Activation energy of low heating rates differs from that of higher rates. - Abstract: The characteristic parameters of devolatilization, the activation energy and the frequency factor, can be obtained following different experimental approaches. In the Distributed Activation Energy Model (DAEM), these parameters are derived from several TGA curves that are typically obtained for constant, low heating rate experiments. Then, the results are used to model high heating rate processes typical of industrial combustors. In this work, a wide range of heating rates were employed to obtain different TGA curves of the biomass pyrolysis, in order to analyse the validity of DAEM when extrapolating the kinetic parameters obtained for low heating rate curves used in the laboratory to higher heating rates present in industrial applications. The TGA curves of the biomass pyrolysis employed in DAEM were varied from low heating rates (around 10 K/min, values typically found in the literature on DAEM), to high heating rates (up to 200 K/min). The differences in the activation energy and the frequency factor obtained for different heating rates, were evaluated and the validity of the model was discussed. The results show differences between the activation energy and the frequency factor obtained using low and high heating rates during the TGA tests. Therefore, if an accurate approximation is required when extrapolating the data to high heating rates, the tests should be carried out at high heating rates

  7. Active Distributed Temperature Sensing to Characterise Soil Moisture and Heat Dynamics of a Vegetated Hillslope.

    Science.gov (United States)

    Ciocca, F.; Krause, S.; Chalari, A.; Hannah, D. M.; Mondanos, M.

    2015-12-01

    Complex correlated water and heat dynamics characterise the land surface and shallow subsurface, as consequence of the concurrent action of multiple transport processes. Point sensors and/or remote techniques show limitations in providing precise measurements of key indicators of soil heat and water transport such as soil temperature and moisture, at both high spatiotemporal resolution and large areal coverage. Fibre optics Distributed Temperature Sensors (DTS) allow for precise temperature measurement along optical cables of up to several kilometres, sampling at resolutions of up to few centimetres in space and seconds in time. The optical cable is the sensor and can be buried in the soil with minimum disturbance, to construct soil temperature profiles, over large surveying areas. Soil moisture can be obtained from the analysis of both heating and cooling rates measured by the DTS, when copper conductors embedded in the optical cable are electrically heated (technique known as Active DTS). In July 2015, three loops of optical cable of 500m each have been buried in the soil at different depths (0.05m, 0.25m and 0.40m), along an inclined recently vegetated field in the Birmingham area, UK. Active DTS tests have been set with the aim to characterize the soil temperature and moisture regimes of the field at high spatial resolution, in response to both sporadic events such as showers or scheduled irrigation, and diurnal fluctuations induced by atmospheric forcing. Spatiotemporal variations of the aforementioned regimes will be used to trace vertical and horizontal soil heat and water movements. Finally, assumptions on the possibility to correlate soil heat and water dynamics to a specific process such as precipitation, evapotranspiration, soil inclination, will be discussed. This research is part of the Marie Curie Initial Training Network (ITN) INTERFACES project and is realised in the context of the Free Air Carbon Enrichment (FACE) experiment, in collaboration with

  8. Experimental investigation on the thermal performance of heat storage walls coupled with active solar systems

    Science.gov (United States)

    Zhao, Chunyu; You, Shijun; Zhu, Chunying; Yu, Wei

    2016-02-01

    This paper presents an experimental investigation of the performance of a system combining a low-temperature water wall radiant heating system and phase change energy storage technology with an active solar system. This system uses a thermal storage wall that is designed with multilayer thermal storage plates. The heat storage material is expanded graphite that absorbs a mixture of capric acid and lauric acid. An experiment is performed to study the actual effect. The following are studied under winter conditions: (1) the temperature of the radiation wall surface, (2) the melting status of the thermal storage material in the internal plate, (3) the density of the heat flux, and (4) the temperature distribution of the indoor space. The results reveal that the room temperature is controlled between 16 and 20 °C, and the thermal storage wall meets the heating and temperature requirements. The following are also studied under summer conditions: (1) the internal relationship between the indoor temperature distribution and the heat transfer within the regenerative plates during the day and (2) the relationship between the outlet air temperature and inlet air temperature in the thermal storage wall in cooling mode at night. The results indicate that the indoor temperature is approximately 27 °C, which satisfies the summer air-conditioning requirements.

  9. Psychosocial predictors of decay in healthy eating and physical activity improvements in obese women regaining lost weight: translation of behavioral theory into treatment suggestions.

    Science.gov (United States)

    Annesi, James J

    2016-06-01

    Regain of lost weight is a universal problem for behavioral treatments. An increased understanding of theory-based psychosocial predictors of decay in behavioral correlates of weight loss might improve treatments. Data were derived from a previous weight loss investigation of 110 women with obesity. A subsample from the experimental treatment who lost ≥3 % body weight and regained at least one third of that over 24 months (N = 36) was assessed. During months 6 through 24, there were unfavorable changes in behavioral (fruit/vegetable and sweet intake; physical activity) and psychosocial variables. Mood change predicted change in fruit/vegetable and sweet intake, with emotional eating change mediating the latter relationship. Change in self-regulation predicted changes in sweet and fruit/vegetable intake and physical activity, with self-efficacy mediating the self-regulation-fruit/vegetable intake and self-regulation-physical activity relationships. Findings suggest that after treatment-induced weight loss, addressing indicated theory-based psychosocial variables might mitigate decay in behavioral predictors of healthier weight. PMID:27052217

  10. Heating Treated Carbon Nanotubes As Highly Active Electrocatalysts for Oxygen Reduction Reaction

    International Nuclear Information System (INIS)

    Graphical abstract: Heating treatment for multi-walled carbon nanotubes in the air introduces abundant structure defects which improve catalytic performances for oxygen reduction reaction (ORR). There is a positive correlation between the defect levels and ORR activities. The product shows better methanol tolerance and long-term durability than commercial Pt/C which makes it applicable in fuel cells. - Abstract: Carbon nanotubes (CNTs) have been widely developed for electrochemical energy conversion and storage devices for replacement of high-cost Pt-based catalysts. In this paper, a simple and convenient method is developed for improving the catalytic activity of CNTs in a controlled way. By simple heating treatment in the air, the multi-walled carbon nanotubes (MWCNTs) change with special morphologies, compositions and abundant defects (denoted as h-CNT). Those defects significantly improve the electrocatalytic performances for oxygen reduction reaction (ORR) which proceeds in a nearly four-electron pathway. The heating conditions have important effects on the structures and defect properties of h-CNTs which show a positive correlation between the defect levels and ORR performances. The small amounts of iron residues originated from nanotube growth and nitrogen doping during heating treatment also contribute to some catalytic activity. The inner walls of h-CNT remain intact during heating treatment and provide sufficient conductivity which facilitates charge transport during ORR. The h-CNT electrocatalyst shows better methanol tolerance and long-term durability than commercial Pt/C in alkaline media which makes it an alternative cathode catalyst in fuel cells

  11. Heat Shock Factor 1 Is a Substrate for p38 Mitogen-Activated Protein Kinases.

    Science.gov (United States)

    Dayalan Naidu, Sharadha; Sutherland, Calum; Zhang, Ying; Risco, Ana; de la Vega, Laureano; Caunt, Christopher J; Hastie, C James; Lamont, Douglas J; Torrente, Laura; Chowdhry, Sudhir; Benjamin, Ivor J; Keyse, Stephen M; Cuenda, Ana; Dinkova-Kostova, Albena T

    2016-09-15

    Heat shock factor 1 (HSF1) monitors the structural integrity of the proteome. Phosphorylation at S326 is a hallmark for HSF1 activation, but the identity of the kinase(s) phosphorylating this site has remained elusive. We show here that the dietary agent phenethyl isothiocyanate (PEITC) inhibits heat shock protein 90 (Hsp90), the main negative regulator of HSF1; activates p38 mitogen-activated protein kinase (MAPK); and increases S326 phosphorylation, trimerization, and nuclear translocation of HSF1, and the transcription of a luciferase reporter, as well as the endogenous prototypic HSF1 target Hsp70. In vitro, all members of the p38 MAPK family rapidly and stoichiometrically catalyze the S326 phosphorylation. The use of stable knockdown cell lines and inhibitors indicated that among the p38 MAPKs, p38γ is the principal isoform responsible for the phosphorylation of HSF1 at S326 in cells. A protease-mass spectrometry approach confirmed S326 phosphorylation and unexpectedly revealed that p38 MAPK also catalyzes the phosphorylation of HSF1 at S303/307, previously known repressive posttranslational modifications. Thus, we have identified p38 MAPKs as highly efficient catalysts for the phosphorylation of HSF1. Furthermore, our findings suggest that the magnitude and persistence of activation of p38 MAPK are important determinants of the extent and duration of the heat shock response. PMID:27354066

  12. Observations of HF backscatter decay rates from HAARP generated FAI

    Science.gov (United States)

    Bristow, William; Hysell, David

    2016-07-01

    Suitable experiments at the High-frequency Active Auroral Research Program (HAARP) facilities in Gakona, Alaska, create a region of ionospheric Field-Aligned Irregularities (FAI) that produces strong radar backscatter observed by the SuperDARN radar on Kodiak Island, Alaska. Creation of FAI in HF ionospheric modification experiments has been studied by a number of authors who have developed a rich theoretical background. The decay of the irregularities, however, has not been so widely studied yet it has the potential for providing estimates of the parameters of natural irregularity diffusion, which are difficult measure by other means. Hysell, et al. [1996] demonstrated using the decay of radar scatter above the Sura heating facility to estimate irregularity diffusion. A large database of radar backscatter from HAARP generated FAI has been collected over the years. Experiments often cycled the heater power on and off in a way that allowed estimates of the FAI decay rate. The database has been examined to extract decay time estimates and diffusion rates over a range of ionospheric conditions. This presentation will summarize the database and the estimated diffusion rates, and will discuss the potential for targeted experiments for aeronomy measurements. Hysell, D. L., M. C. Kelley, Y. M. Yampolski, V. S. Beley, A. V. Koloskov, P. V. Ponomarenko, and O. F. Tyrnov, HF radar observations of decaying artificial field aligned irregularities, J. Geophys. Res. , 101, 26,981, 1996.

  13. The SIRT1 modulators AROS and DBC1 regulate HSF1 activity and the heat shock response.

    Directory of Open Access Journals (Sweden)

    Rachel Raynes

    Full Text Available The heat shock response, the cellular response to protein damaging stress, is critical in maintaining proteostasis. The heat shock response is regulated by the transcription factor HSF1, which is activated upon heat shock and other stresses to induce the expression of molecular chaperones. SIRT1 has previously been shown to activate HSF1 by deacetylating it, leading to increased DNA binding ability. We have investigated how the heat shock response may be controlled by factors influencing SIRT1 activity. We found that heat shock results in an increase in the cellular NAD(+/NADH ratio and an increase in recruitment of SIRT1 to the hsp70 promoter. Furthermore, we found that the SIRT1 modulators AROS and DBC1 have an impact on hsp70 transcription, HSF1 acetylation status, and HSF1 recruitment to the hsp70 promoter. Therefore, AROS and DBC1 are now two new targets available for therapeutic regulation of the heat shock response.

  14. Combustion instability and active control: Alternative fuels, augmentors, and modeling heat release

    Science.gov (United States)

    Park, Sammy Ace

    Experimental and analytical studies were conducted to explore thermo-acoustic coupling during the onset of combustion instability in various air-breathing combustor configurations. These include a laboratory-scale 200-kW dump combustor and a 100-kW augmentor featuring a v-gutter flame holder. They were used to simulate main combustion chambers and afterburners in aero engines, respectively. The three primary themes of this work includes: 1) modeling heat release fluctuations for stability analysis, 2) conducting active combustion control with alternative fuels, and 3) demonstrating practical active control for augmentor instability suppression. The phenomenon of combustion instabilities remains an unsolved problem in propulsion engines, mainly because of the difficulty in predicting the fluctuating component of heat release without extensive testing. A hybrid model was developed to describe both the temporal and spatial variations in dynamic heat release, using a separation of variables approach that requires only a limited amount of experimental data. The use of sinusoidal basis functions further reduced the amount of data required. When the mean heat release behavior is known, the only experimental data needed for detailed stability analysis is one instantaneous picture of heat release at the peak pressure phase. This model was successfully tested in the dump combustor experiments, reproducing the correct sign of the overall Rayleigh index as well as the remarkably accurate spatial distribution pattern of fluctuating heat release. Active combustion control was explored for fuel-flexible combustor operation using twelve different jet fuels including bio-synthetic and Fischer-Tropsch types. Analysis done using an actuated spray combustion model revealed that the combustion response times of these fuels were similar. Combined with experimental spray characterizations, this suggested that controller performance should remain effective with various alternative fuels

  15. THE WAY OF GENERATION THE HIGH-GRADE HEAT ENERGY DURING +- AND –– DECAY IN THE CHAIN NOT-RAMIFIED NUCLEAR TRANSFORMATIONS

    OpenAIRE

    Лавренченко, Г. К.; Семенишин, Н. Н.; Волков, В. Е.; Куриннов, Г. В.

    2015-01-01

    The present ways of reception the high-grade heat energy (HGHE) with temperatures higher 2500 K have a number of defects, the main of which — low efficiency. In the generator realizing an offered new way of manufacture HGHE as a working body is used superheated water vapor. On the initial stage in process of plasma-formation in a flow of water vapor are appears the oxygen’s ions, hydroxyls, free electrons and what most important — protons. Protons are separate the from this flow during its pa...

  16. Heat production and quantitative oxidation of nutrients by physical activity in humans

    DEFF Research Database (Denmark)

    Thorbek, G; Chwalibog, André; Jakobsen, K;

    1994-01-01

    The effect of physical activity on heat production and oxidation of nutrients was measured by means of indirect calorimetry. The experiment included 6 male and 4 female healthy subjects who, during a 24-hour stay in the respiration chambers, performed, in the morning and afternoon, 15 min cycling...... with the total work of 6,750 kg m. Experiments were repeated twice (3- to 4-week interval) showing no differences between the gas exchange in the morning and afternoon and between first and second experiment. The gas exchange during cycling was about 4 times higher than during basal periods. The identical work...... of 66.2 kJ by cycling caused on average a heat increment of 309 kJ, yielding the mean energetic efficiency for the performed work of 0.22. The activity caused an increment of 11.5 g oxidized carbohydrate and 2.6 g oxidized fat....

  17. The decay of 120Ba

    International Nuclear Information System (INIS)

    120Ba was produced by bombarding a 2 mg/cm2 thick 106Cd target with a 68 MeV 16O beam and fluorated in a helium-jet ion source. The decay of on-line mass separated activity 120Ba has been studied by γ-X, γ-γ and γ-β coincidence measurements. Its half-life was measured to be 24 ± 2s. The total decay energy was extracted to be QEG 5.0 ± 0.3 MeV. A simple decay scheme has been proposed

  18. Hybrid ground-source heat pump system with active air source regeneration

    International Nuclear Information System (INIS)

    Highlights: • A hybrid ground source heat pump system with two separate borefields is modelled. • The maximum underground storage temperature depends on the size of the drycooler. • Drycooler selection curves are given as function of underground storage temperature. • The size of the cold storage is reduced with 47% in the cost optimal configuration. • The cooling seasonal performance factor decreases with reduced storage capacity. - Abstract: Ground-source heat pump systems (GSHP) offer great advantages over traditional heating and cooling installations. However, their applications are limited due to the high initial costs of borehole drilling. One way to avoid these costs is by reducing the size of the borefield, e.g. by combining the system with other renewable energy sources or by using active regeneration to increase the system efficiency. In this paper a hybrid ground-source heat pump system (HGSHP) is analyzed. The borefield is split into a warm part and a cold part, which allows for seasonal thermal-energy storage. Additionally, supplementary drycoolers capture heat during summer and cold during winter. The relationship between the underground storage size and temperature and the drycooler capacity is described, using an office building in Flanders (Belgium) as reference case. Results show that with a HGSHP system a significant borefield size reduction can be achieved without compromising system performance; i.e. for the reference case a reduction of 47% was achieved in the cost-optimal configuration. It is also shown that the cooling seasonal performance factor decreases significantly with underground storage capacity. In addition, the HGSHP can be used to maintain or restore thermal balance in the geothermal source when heating and cooling loads do not match

  19. Heat stress and antioxidant enzyme activity in bubaline (Bubalus bubalis) oocytes during in vitro maturation

    Science.gov (United States)

    Waiz, Syma Ashraf; Raies-ul-Haq, Mohammad; Dhanda, Suman; Kumar, Anil; Goud, T. Sridhar; Chauhan, M. S.; Upadhyay, R. C.

    2016-01-01

    In vitro environments like heat stress usually increase the production of reactive oxygen species in bubaline oocytes which have been implicated as one of the major causes for reduced developmental competence. Oocytes during meiotic maturation are sensitive to oxidative stress, and heat stress accelerates cellular metabolism, resulting in the higher production of free radicals. Therefore, the aim of present work was to assess the impact of heat stress during meiotic maturation on bubaline cumulus-oocyte complexes (COC), denuded oocytes (DO), and cumulus cell mass in terms of their oxidative status. Accordingly, for control group, COC were matured at 38.5 °C for complete 24 h of meiotic maturation and heat stress of 40.5 and 41.5 °C was applied to COC during the first 12 h of maturation and then moved to 38.5 °C for rest of the 12 h. In another group, COC after maturation were denuded from the surrounding cumulus cells by manual pipetting. Results indicated that the production of reactive oxygen species (ROS), lipid peroxides, and nitric oxide (NO) was significantly (P < 0.05) higher in the oocytes subjected to heat stress (40.5 and 41.5 °C) during meiotic maturation compared to the oocytes matured under standard in vitro culture conditions (38.5 °C). Also, the antioxidant enzymatic activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase were significantly (P < 0.05) increased in all the treatment groups compared to the control group. Therefore, the present study clearly establishes that heat stress ensues oxidative stress in bubaline oocytes which triggers the induction of antioxidant enzymatic defense system for scavenging the ROS.

  20. Thermoregulation and heat exchange in a nonuniform thermal environment during simulated extended EVA. Extravehicular activities

    Science.gov (United States)

    Koscheyev, V. S.; Leon, G. R.; Hubel, A.; Nelson, E. D.; Tranchida, D.

    2000-01-01

    BACKGROUND: Nonuniform heating and cooling of the body, a possibility during extended duration extravehicular activities (EVA), was studied by means of a specially designed water circulating garment that independently heated or cooled the right and left sides of the body. The purpose was to assess whether there was a generalized reaction on the finger in extreme contradictory temperatures on the body surface, as a potential heat status controller. METHOD: Eight subjects, six men and two women, were studied while wearing a sagittally divided experimental garment with hands exposed in the following conditions: Stage 1 baseline--total body garment inlet water temperature at 33 degrees C; Stage 2--left side inlet water temperature heated to 45 degrees C; right side cooled to 8 degrees C; Stage 3--left side inlet water temperature cooled to 8 degrees C, right side heated to 45 degrees C. RESULTS: Temperatures on each side of the body surface as well as ear canal temperature (Tec) showed statistically significant Stage x Side interactions, demonstrating responsiveness to the thermal manipulations. Right and left finger temperatures (Tfing) were not significantly different across stages; their dynamic across time was similar. Rectal temperature (Tre) was not reactive to prevailing cold on the body surface, and therefore not informative. Subjective perception of heat and cold on the left and right sides of the body was consistent with actual temperature manipulations. CONCLUSIONS: Tec and Tre estimates of internal temperature do not provide accurate data for evaluating overall thermal status in nonuniform thermal conditions on the body surface. The use of Tfing has significant potential in providing more accurate information on thermal status and as a feedback method for more precise thermal regulation of the astronaut within the EVA space suit.

  1. Heat-Activated Effect of Exchange Coupling Between Two Ferromagnets Separated by an Amorphous Semiconducting Barrier

    Institute of Scientific and Technical Information of China (English)

    肖明文; 李正中; 许望

    2002-01-01

    We try to extend our previous zero-temperature tunnelling theory for the exchange coupling between two ferromagnets separated by an amorphous semiconducting barrier to the case of finite temperature. The result exhibits that the tunnelling electrons can absorb or emit phonons when they tunnel through the amorphous barrier at finite temperatures so that the interlayer exchange coupling is heat activated. This agrees with the experiments.

  2. Enhancement of anaerobic biohydrogen/methane production from cellulose using heat-treated activated sludge.

    Science.gov (United States)

    Lay, C H; Chang, F Y; Chu, C Y; Chen, C C; Chi, Y C; Hsieh, T T; Huang, H H; Lin, C Y

    2011-01-01

    Anaerobic digestion is an effective technology to convert cellulosic wastes to methane and hydrogen. Heat-treatment is a well known method to inhibit hydrogen-consuming bacteria in using anaerobic mixed cultures for seeding. This study aims to investigate the effects of heat-treatment temperature and time on activated sludge for fermentative hydrogen production from alpha-cellulose by response surface methodology. Hydrogen and methane production was evaluated based on the production rate and yield (the ability of converting cellulose into hydrogen and methane) with heat-treated sludge as the seed at various temperatures (60-97 degrees C) and times (20-60 min). Batch experiments were conducted at 55 degrees C and initial pH of 8.0. The results indicate that hydrogen and methane production yields peaked at 4.3 mmol H2/g cellulose and 11.6 mmol CH4/g cellulose using the seed activated sludge that was thermally treated at 60 degrees C for 40 min. These parameter values are higher than those of no-treatment seed (HY 3.6 mmol H2/g cellulose and MY 10.4 mmol CH4/g cellulose). The maximum hydrogen production rate of 26.0 mmol H2/L/d and methane production rate of 23.2 mmol CH4/L/d were obtained for the seed activated sludge that was thermally treated at 70 degrees C for 50 min and 60 degrees C for 40 min, respectively.

  3. Semileptonic Decays

    Energy Technology Data Exchange (ETDEWEB)

    Luth, Vera G.; /SLAC

    2012-10-02

    The following is an overview of the measurements of the CKM matrix elements |V{sub cb}| and |V{sub ub}| that are based on detailed studies of semileptonic B decays by the BABAR and Belle Collaborations and major advances in QCD calculations. In addition, a new and improved measurement of the ratios R(D{sup (*)}) = {Beta}({bar B} {yields} D{sup (*)}{tau}{sup -}{bar {nu}}{sub {tau}})/{Beta}({bar B} {yields} D{sup (*)}{ell}{sup -}{bar {nu}}{sub {ell}}) is presented. Here D{sup (*)} refers to a D or a D* meson and {ell} is either e or {mu}. The results, R(D) = 0.440 {+-} 0.058 {+-} 0.042 and R(D*) = 0.332 {+-} 0.024 {+-} 0.018, exceed the Standard Model expectations by 2.0{sigma} and 2.7{sigma}, respectively. Taken together, they disagree with these expectations at the 3.4{sigma} level. The excess of events cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.

  4. Effects of Heat Shock on Photosynthetic Properties, Antioxidant Enzyme Activity, and Downy Mildew of Cucumber (Cucumis sativus L.)

    Science.gov (United States)

    Hao, Ting; Jin, Haijun; Zhang, Hongmei; He, Lizhong; Zhou, Qiang; Huang, Danfeng; Hui, Dafeng; Yu, Jizhu

    2016-01-01

    Heat shock is considered an abiotic stress for plant growth, but the effects of heat shock on physiological responses of cucumber plant leaves with and without downy mildew disease are still not clear. In this study, cucumber seedlings were exposed to heat shock in greenhouses, and the responses of photosynthetic properties, carbohydrate metabolism, antioxidant enzyme activity, osmolytes, and disease severity index of leaves with or without the downy mildew disease were measured. Results showed that heat shock significantly decreased the net photosynthetic rate, actual photochemical efficiency, photochemical quenching coefficient, and starch content. Heat shock caused an increase in the stomatal conductance, transpiration rate, antioxidant enzyme activities, total soluble sugar content, sucrose content, soluble protein content and proline content for both healthy leaves and downy mildew infected leaves. These results demonstrate that heat shock activated the transpiration pathway to protect the photosystem from damage due to excess energy in cucumber leaves. Potential resistance mechanisms of plants exposed to heat stress may involve higher osmotic regulation capacity related to an increase of total accumulations of soluble sugar, proline and soluble protein, as well as higher antioxidant enzymes activity in stressed leaves. Heat shock reduced downy mildew disease severity index by more than 50%, and clearly alleviated downy mildew development in the greenhouses. These findings indicate that cucumber may have a complex physiological change to resist short-term heat shock, and suppress the development of the downy mildew disease. PMID:27065102

  5. Effects of Heat Shock on Photosynthetic Properties, Antioxidant Enzyme Activity, and Downy Mildew of Cucumber (Cucumis sativus L.).

    Science.gov (United States)

    Ding, Xiaotao; Jiang, Yuping; Hao, Ting; Jin, Haijun; Zhang, Hongmei; He, Lizhong; Zhou, Qiang; Huang, Danfeng; Hui, Dafeng; Yu, Jizhu

    2016-01-01

    Heat shock is considered an abiotic stress for plant growth, but the effects of heat shock on physiological responses of cucumber plant leaves with and without downy mildew disease are still not clear. In this study, cucumber seedlings were exposed to heat shock in greenhouses, and the responses of photosynthetic properties, carbohydrate metabolism, antioxidant enzyme activity, osmolytes, and disease severity index of leaves with or without the downy mildew disease were measured. Results showed that heat shock significantly decreased the net photosynthetic rate, actual photochemical efficiency, photochemical quenching coefficient, and starch content. Heat shock caused an increase in the stomatal conductance, transpiration rate, antioxidant enzyme activities, total soluble sugar content, sucrose content, soluble protein content and proline content for both healthy leaves and downy mildew infected leaves. These results demonstrate that heat shock activated the transpiration pathway to protect the photosystem from damage due to excess energy in cucumber leaves. Potential resistance mechanisms of plants exposed to heat stress may involve higher osmotic regulation capacity related to an increase of total accumulations of soluble sugar, proline and soluble protein, as well as higher antioxidant enzymes activity in stressed leaves. Heat shock reduced downy mildew disease severity index by more than 50%, and clearly alleviated downy mildew development in the greenhouses. These findings indicate that cucumber may have a complex physiological change to resist short-term heat shock, and suppress the development of the downy mildew disease. PMID:27065102

  6. Effects of Heat Shock on Photosynthetic Properties, Antioxidant Enzyme Activity, and Downy Mildew of Cucumber (Cucumis sativus L..

    Directory of Open Access Journals (Sweden)

    Xiaotao Ding

    Full Text Available Heat shock is considered an abiotic stress for plant growth, but the effects of heat shock on physiological responses of cucumber plant leaves with and without downy mildew disease are still not clear. In this study, cucumber seedlings were exposed to heat shock in greenhouses, and the responses of photosynthetic properties, carbohydrate metabolism, antioxidant enzyme activity, osmolytes, and disease severity index of leaves with or without the downy mildew disease were measured. Results showed that heat shock significantly decreased the net photosynthetic rate, actual photochemical efficiency, photochemical quenching coefficient, and starch content. Heat shock caused an increase in the stomatal conductance, transpiration rate, antioxidant enzyme activities, total soluble sugar content, sucrose content, soluble protein content and proline content for both healthy leaves and downy mildew infected leaves. These results demonstrate that heat shock activated the transpiration pathway to protect the photosystem from damage due to excess energy in cucumber leaves. Potential resistance mechanisms of plants exposed to heat stress may involve higher osmotic regulation capacity related to an increase of total accumulations of soluble sugar, proline and soluble protein, as well as higher antioxidant enzymes activity in stressed leaves. Heat shock reduced downy mildew disease severity index by more than 50%, and clearly alleviated downy mildew development in the greenhouses. These findings indicate that cucumber may have a complex physiological change to resist short-term heat shock, and suppress the development of the downy mildew disease.

  7. Methods for determining enzymatic activity comprising heating and agitation of closed volumes

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, David Neil; Henriksen, Emily DeCrescenzo; Reed, David William; Jensen, Jill Renee

    2016-03-15

    Methods for determining thermophilic enzymatic activity include heating a substrate solution in a plurality of closed volumes to a predetermined reaction temperature. Without opening the closed volumes, at least one enzyme is added, substantially simultaneously, to the closed volumes. At the predetermined reaction temperature, the closed volumes are agitated and then the activity of the at least one enzyme is determined. The methods are conducive for characterizing enzymes of high-temperature reactions, with insoluble substrates, with substrates and enzymes that do not readily intermix, and with low volumes of substrate and enzyme. Systems for characterizing the enzymes are also disclosed.

  8. Heat stress and antioxidant enzyme activity in bubaline ( Bubalus bubalis) oocytes during in vitro maturation

    Science.gov (United States)

    Waiz, Syma Ashraf; Raies-ul-Haq, Mohammad; Dhanda, Suman; Kumar, Anil; Goud, T. Sridhar; Chauhan, M. S.; Upadhyay, R. C.

    2016-09-01

    In vitro environments like heat stress usually increase the production of reactive oxygen species in bubaline oocytes which have been implicated as one of the major causes for reduced developmental competence. Oocytes during meiotic maturation are sensitive to oxidative stress, and heat stress accelerates cellular metabolism, resulting in the higher production of free radicals. Therefore, the aim of present work was to assess the impact of heat stress during meiotic maturation on bubaline cumulus-oocyte complexes (COC), denuded oocytes (DO), and cumulus cell mass in terms of their oxidative status. Accordingly, for control group, COC were matured at 38.5 °C for complete 24 h of meiotic maturation and heat stress of 40.5 and 41.5 °C was applied to COC during the first 12 h of maturation and then moved to 38.5 °C for rest of the 12 h. In another group, COC after maturation were denuded from the surrounding cumulus cells by manual pipetting. Results indicated that the production of reactive oxygen species (ROS), lipid peroxides, and nitric oxide (NO) was significantly ( P antioxidant enzymatic activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase were significantly ( P antioxidant enzymatic defense system for scavenging the ROS.

  9. Surface chemistry of polyacrylonitrile- and rayon-based activated carbon fibers after post-heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chiang Yuchun [Department of Mechanical Engineering, Yuan Ze University, 135 Yuan-Tung Road, Chung-Li, Taoyuan 320, Taiwan (China)]. E-mail: ycchiang@saturn.yzu.edu.tw; Lee, C.-Y. [Department of Mechanical Engineering, Yuan Ze University, 135 Yuan-Tung Road, Chung-Li, Taoyuan 320, Taiwan (China); Lee, H.-C. [Department of Mechanical Engineering, Yuan Ze University, 135 Yuan-Tung Road, Chung-Li, Taoyuan 320, Taiwan (China)

    2007-01-15

    Polyacrylonitrile- and rayon-based activated carbon fibers (ACFs) subject to heat treatment were investigated by means of elemental analyzer, and X-ray photoelectron spectroscopy (XPS). The total ash content of all ACFs was also analyzed. The adsorption of benzene, carbon tetrachloride and water vapor on ACFs was determined to shed light on the role of surface chemistry on gas adsorption. Results show that different precursors resulted in various elemental compositions and imposed diverse influence upon surface functionalities after heat treatment. The surface of heat-treated ACFs became more graphitic and hydrophobic. Three distinct peaks due to C, N, and O atoms were identified by XPS, and the high-resolution revealed the existence of several surface functionalities. The presence of nitride-like species, aromatic N-imines, or chemisorbed nitrogen oxides was found to be of great advantage to adsorption of water vapor or benzene, but the pyridine-N was not. Unstable complexes on the surface would hinder the fibers from adsorption of carbon tetrachloride. The rise in total ash content or hydrogen composition was of benefit to the access of water vapor. Modifications of ACFs by heat treatment have effectively improved adsorption performance.

  10. Procedure of Active Residual Heat Removal after Emergency Shutdown of High-Temperature-Gas-Cooled Reactor

    Directory of Open Access Journals (Sweden)

    Xingtuan Yang

    2014-01-01

    Full Text Available After emergency shutdown of high-temperature-gas-cooled reactor, the residual heat of the reactor core should be removed. As the natural circulation process spends too long period of time to be utilized, an active residual heat removal procedure is needed, which makes use of steam generator and start-up loop. During this procedure, the structure of steam generator may suffer cold/heat shock because of the sudden load of coolant or hot helium at the first few minutes. Transient analysis was carried out based on a one-dimensional mathematical model for steam generator and steam pipe of start-up loop to achieve safety and reliability. The results show that steam generator should be discharged and precooled; otherwise, boiling will arise and introduce a cold shock to the boiling tubes and tube sheet when coolant began to circulate prior to the helium. Additionally, in avoiding heat shock caused by the sudden load of helium, the helium circulation should be restricted to start with an extreme low flow rate; meanwhile, the coolant of steam generator (water should have flow rate as large as possible. Finally, a four-step procedure with precooling process of steam generator was recommended; sensitive study for the main parameters was conducted.

  11. Pulsed nanosecond discharge in air at high specific deposited energy: fast gas heating and active particle production

    Science.gov (United States)

    Popov, N. A.

    2016-08-01

    The results of a numerical study on kinetic processes initiated by a pulsed nanosecond discharge in air at high specific deposited energy, when the dissociation degree of oxygen molecules is high, are presented. The calculations of the temporal dynamics of the electron concentration, density of atomic oxygen, vibrational distribution function of nitrogen molecules, and gas temperature agree with the experimental data. It is shown that quenching of electronically excited states of nitrogen N2(B3Πg), N2(С3Πu), N2(a‧1 Σ \\text{u}- ) by oxygen molecules leads to the dissociation of O2. This conclusion is based on the comparison of calculated dynamics of atomic oxygen in air, excited by a pulsed nanosecond discharge, with experimental data. In air plasma at a high dissociation degree of oxygen molecules ([O]/[O2]  >  10%), relaxation of the electronic energy of atoms and molecules in reactions with O atoms becomes extremely important. Active production of NO molecules and fast gas heating in the discharge plasma due to the quenching of electronically excited N2(B3Πg, C3Πu, a‧1 Σ \\text{u}- ) molecules by oxygen atoms is notable. Owing to the high O atom density, electrons are effectively detached from negative ions in the discharge afterglow. As a result, the decay of plasma in the afterglow is determined by electron–ion recombination, and the electron density remains relatively high between the pulses. An increase in the vibrational temperature of nitrogen molecules at the periphery of the plasma channel at time delay t  =  1–30 μs after the discharge is obtained. This is due to intense gas heating and, as a result, gas-dynamic expansion of a hot gas channel. Vibrationally excited N2(v) molecules produced near the discharge axis move from the axial region to the periphery. Consequently, at the periphery the vibrational temperature of nitrogen molecules is increased.

  12. Decay constants in geochronology

    Institute of Scientific and Technical Information of China (English)

    IgorM.Villa; PaulR.Renne

    2005-01-01

    Geologic time is fundamental to the Earth Sciences, and progress in many disciplines depends critically on our ability to measure time with increasing accuracy and precision. Isotopic geochronology makes use of the decay of radioactive nuclides as a help to quantify the histories of rock, minerals, and other materials. Both accuracy and precision of radioisotopic ages are, at present, limited by those of radioactive decay constants. Modem mass spectrometers can measure isotope ratios with a precision of 10-4 or better. On the other hand, the uncertainties associated with direct half-life determinations are, in most cases, still at the percent level. The present short note briefly summarizes progress and problems that have been encountered during the Working Group's activity.

  13. Decay of Hoyle state

    Indian Academy of Sciences (India)

    S Bhattacharya; T K Rana; C Bhattacharya; S Kundu; K Banerjee; T K Ghosh; G Mukherjee; R Pandey; P Roy

    2014-11-01

    The prediction of Hoyle state was necessitated to explain the abundance of carbon, which is crucial for the existence of life on Earth and is the stepping stone for understanding the abundance of other heavier elements. After the experimental confirmation of its existence, soon it was realized that the Hoyle state was `different’ from other excited states of carbon, which led to intense theoretical and experimental activities over the past few decades to understand its structure. In recent times, precision, high statistics experiments on the decay of Hoyle state have been performed at the Variable Energy Cyclotron Centre, to determine the quantitative contributions of various direct 3 decay mechanisms of the Hoyle state. The present results have been critically compared with those obtained in other recent experiments and their implications have been discussed.

  14. Weight Optimization of Active Thermal Management Using a Novel Heat Pump

    Science.gov (United States)

    Lear, William E.; Sherif, S. A.

    2004-01-01

    Efficient lightweight power generation and thermal management are two important aspects for space applications. Weight is added to the space platforms due to the inherent weight of the onboard power generation equipment and the additional weight of the required thermal management systems. Thermal management of spacecraft relies on rejection of heat via radiation, a process that can result in large radiator mass, depending upon the heat rejection temperature. For some missions, it is advantageous to incorporate an active thermal management system, allowing the heat rejection temperature to be greater than the load temperature. This allows a reduction of radiator mass at the expense of additional system complexity. A particular type of active thermal management system is based on a thermodynamic cycle, developed by the authors, called the Solar Integrated Thermal Management and Power (SITMAP) cycle. This system has been a focus of the authors research program in the recent past (see Fig. 1). One implementation of the system requires no moving parts, which decreases the vibration level and enhances reliability. Compression of the refrigerant working fluid is accomplished in this scheme via an ejector.

  15. 主动蓄放热-热泵联合加温系统在日光温室的应用%Application of heating system with active heat storage-release and heat pump in solar greenhouse

    Institute of Scientific and Technical Information of China (English)

    孙维拓; 杨其长; 方慧; 张义; 管道平; 卢威

    2013-01-01

    The Chinese solar greenhouse has a unique greenhouse structure that regards solar energy as the main energy source, and has characteristics such as high efficiency, energy saving, and low cost. During a cold winter night, air temperature inside a solar greenhouse is low for crop growth, which would affect crop yield and quality, due to the heat-transfer characteristics and heat capacity limit of the north wall. In recent years, in trying to promote the heat storage capacity of the solar greenhouse, the thought of active heat storage-release came forward. Solar energy is a kind of clean renewable energy, but has intermittent and unstable performance when used for greenhouse heating. Meanwhile, the heat collecting efficiency of the solar thermal collector decreases with an increase in operating temperature. Thus, an active heat storage-release system (AHSRS) is difficult to use to ensure an appropriate temperature for a solar greenhouse in a frigid region or when it encounters weather conditions with weak solar radiation. As an efficient means of raising low-grade energy, the heat pump has been more and more applied to greenhouse heating which can reduce the operating temperature of the AHSRS when used in combination. In order to promote heating performance and stability of the AHSRS and improve air temperature inside a solar greenhouse at night, based on the concept of active heat storage-release, an active heat storage-release associated with heat pump heating system (AHSRHPS) applicable to solar greenhouse heating was designed in the present study. During the day, the solar energy reaching the north wall surface was absorbed by the circulating water and stored in reservoirs when the AHSRS was running. Running the heat pump unit was intended to promote low-grade heat energy and reduce the circulating water temperature which contributes to increasing the heat collecting efficiency of the AHSRS and maximum water temperature of the reservoir. When air temperature

  16. Cardiac activation heat remains inversely dependent on temperature over the range 27-37°C.

    Science.gov (United States)

    Johnston, Callum M; Han, June-Chiew; Loiselle, Denis S; Nielsen, Poul M F; Taberner, Andrew J

    2016-06-01

    The relation between heat output and stress production (force per cross-sectional area) of isolated cardiac tissue is a key metric that provides insight into muscle energetic performance. The heat intercept of the relation, termed "activation heat," reflects the metabolic cost of restoring transmembrane gradients of Na(+) and K(+) following electrical excitation, and myoplasmic Ca(2+) concentration following its release from the sarcoplasmic reticulum. At subphysiological temperatures, activation heat is inversely dependent on temperature. Thus one may presume that activation heat would decrease even further at body temperature. However, this assumption is prima facie inconsistent with a study, using intact hearts, which revealed no apparent change in the combination of activation and basal metabolism between 27 and 37°C. It is thus desired to directly determine the change in activation heat between 27 and 37°C. In this study, we use our recently constructed high-thermal resolution muscle calorimeter to determine the first heat-stress relation of isolated cardiac muscle at 37°C. We compare the relation at 37°C to that at 27°C to examine whether the inverse temperature dependence of activation heat, observed under hypothermic conditions, prevails at body temperature. Our results show that activation heat was reduced (from 3.5 ± 0.3 to 2.3 ± 0.3 kJ/m(3)) at the higher temperature. This leads us to conclude that activation metabolism continues to decline as temperature is increased from hypothermia to normothermia and allows us to comment on results obtained from the intact heart by previous investigators.

  17. Detrended analysis of Reynolds stress in a decaying turbulent flow in a wind tunnel with active grids

    Institute of Scientific and Technical Information of China (English)

    黄永祥; 卢志明

    2014-01-01

    Multi-scale properties of Reynolds stress in decaying turbulence in a wind tunnel with high Reynolds number are investi-gated. Two filtering techniques i.e., the zeroth-order and first-order detrending methods are applied to the two velocity components, where the local mean value (resp. local linear trend) is removed in the former (latter) technique. Some basic statistics for thirty mea-surements show that the variation is very large at first two locations and relatively small at last two locations. Moderately good power law is found for the mean value of local Reynolds stress at last three measurement locations with scaling exponents approxi-mately being 1.0 and a dual power law exists for the mean value of standard deviation of local Reynolds stress at all four measureme-nt locations with scaling exponents being 0.53 and 0.58 for zeroth-and first-order filtering respectively. Present results about local Reynolds stress are useful to build and evaluate the model of sub-grid Reynolds stress in large eddy simulations.

  18. Radioactive decay data tables

    International Nuclear Information System (INIS)

    The estimation of radiation dose to man from either external or internal exposure to radionuclides requires a knowledge of the energies and intensities of the atomic and nuclear radiations emitted during the radioactive decay process. The availability of evaluated decay data for the large number of radionuclides of interest is thus of fundamental importance for radiation dosimetry. This handbook contains a compilation of decay data for approximately 500 radionuclides. These data constitute an evaluated data file constructed for use in the radiological assessment activities of the Technology Assessments Section of the Health and Safety Research Division at Oak Ridge National Laboratory. The radionuclides selected for this handbook include those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion reactor technology, and some of those of interest to Committee 2 of the International Commission on Radiological Protection for the estimation of annual limits on intake via inhalation and ingestion for occupationally exposed individuals

  19. Neutral-Line Magnetic Shear and Enhanced Coronal Heating in Solar Active Regions

    Science.gov (United States)

    Falconer, D. A.; Moore, R. L.; Porter, J. G.; Gary, G. A.; Shimizu, T.

    1997-01-01

    By examining the magnetic structure at sites in the bright coronal interiors of active regions that are not flaring but exhibit persistent strong coronal heating, we establish some new characteristics of the magnetic origins of this heating. We have examined the magnetic structure of these sites in five active regions, each of which was well observed by both the Yohkoh SXT and the Marshall Space Flight Center Vector Magnetograph and showed strong shear in its magnetic field along part of at least one neutral line (polarity inversion). Thus, we can assess whether this form of nonpotential field structure in active regions is a characteristic of the enhanced coronal heating and vice versa. From 27 orbits' worth of Yohkoh SXT images of the five active regions, we have obtained a sample of 94 persistently bright coronal features (bright in all images from a given orbit), 40 long (greater than or approximately equals 20,000 km) neutral-line segments having strong magnetic shear throughout (shear angle greater than 45 deg), and 39 long neutral-line segments having weak magnetic shear throughout (shear angle less than 45 deg). From this sample, we find that: (1) all of our persistently bright coronal features are rooted in magnetic fields that are stronger than 150 G; (2) nearly all (95%) of these enhanced coronal features are rooted near neutral lines (closer than 10,000 km); (3) a great majority (80%) of the bright features are rooted near strong-shear portions of neutral lines; (4) a great majority (85%) of long strong-shear segments of neutral lines have persistently bright coronal features rooted near them; (5) a large minority (40%) of long weak-shear segments of neutral lines have persistently bright coronal features rooted near them; and (6) the brightness of a persistently bright Coronal feature often changes greatly over a few hours. From these results, we conclude that most persistent enhanced heating of coronal loops in active regions: (1) requires the

  20. Comparison of swimming pools alternative passive and active heating systems based on renewable energy sources in Southern Europe

    International Nuclear Information System (INIS)

    This article examines different passive and active heating systems for swimming pools. The passive systems introduced in this article are: * The swimming pools' enclosure. * The placement of floating insulating covers on the pools' surfaces whenever they are not used. The examined active systems in this article are: * A biomass heater. * A biomass heater and solar collectors combi-system. * Vertical geothermal heat exchangers (GHE) co-operating with geothermal heat pumps (GHP). The methodology employed for the introduced systems' evaluation is the arithmetic computational simulation of the swimming pools' annual heating, using annual time series of averaged hourly values for the available solar radiation and the calculated pools' thermal power demand (heating loads). The dimensioning of the active systems aims at the maximisation of the heating production from R.E.S. (renewable energy sources). and the optimisation of the corresponding investments' economic indexes. The examined systems are evaluated technically and economically versus fundamental criteria. It is proved that significant reduction of the heating loads is achieved with the introduced passive systems. The reduced swimming pools' heating loads can be successfully covered by the proposed R.E.S. active systems. The fossil fuels consumption is eliminated. The corresponding investments' payback periods can be lower than 5 years. - Highlights: • The passive solar systems reduce the swimming pools heating loads more than 90%. • The examined active heating system exhibit payback periods lower than 3.5 years. • The energy saving is maximised with a biomass heater – solar collectors system. • Single biomass heaters exhibits the shortest payback period. • GHE–GHP can be used in cases of low solar radiation and lack of biomass fuels

  1. Investigation of heat treating conditions for enhancing the anti-inflammatory activity of citrus fruit (Citrus reticulata) peels.

    Science.gov (United States)

    Ho, Su-Chen; Lin, Chih-Cheng

    2008-09-10

    In traditional Chinese medicine, dried citrus fruit peels are widely used as remedies to alleviate coughs and reduce phlegm in the respiratory tract. Induction of inducible nitric oxide synthase (iNOS) in inflammatory cells and increased airway production of nitric oxide (NO) are well recognized as key events in inflammation-related respiratory tract diseases. Despite the fact that the enhancing effect of heat treatment on the antioxidant activity of citrus fruit peels has been well documented, the impact of heat treatment on citrus peel beneficial activities regarding anti-inflammation is unclear. To address this issue, we determined the anti-inflammatory activities of heat-treated citrus peel extracts by measuring their inhibitory effect upon NO production by lipopolysaccharide-activated RAW 264.7 macrophages. Results showed that the anti-inflammatory activity of citrus peel was significantly elevated after 100 degrees C heat treatment in a time-dependent fashion during a period from 0 to 120 min. Inhibition of iNOS gene expression was the major NO-suppressing mechanism of the citrus peel extract. Additionally, the anti-inflammatory activity of citrus peel extract highly correlated with the content of nobiletin and tangeretin. Conclusively, proper and reasonable heat treatment helped to release nobiletin and tangeretin, which were responsible for the increased anti-inflammatory activity of heat-treated citrus peels. PMID:18683945

  2. Dual-reporter in vivo imaging of transient and inducible heat-shock promoter activation.

    Science.gov (United States)

    Fortin, Pierre-Yves; Genevois, Coralie; Chapolard, Mathilde; Santalucía, Tomàs; Planas, Anna M; Couillaud, Franck

    2014-02-01

    Gene promoter activity can be studied in vivo by molecular imaging methods using reporter gene technology. Transcription of the reporter and the reported genes occurs simultaneously. However, imaging depends on reporter protein translation, stability, and cellular fate that may differ among the various proteins. A double transgenic mouse strain expressing the firefly luciferase (lucF) and fluorescent mPlum protein under the transcriptional control of the thermo-inducible heat-shock protein (Hspa1b) promoter was generated allowing to follow up the reporter proteins by different and complementary in vivo imaging technologies. These mice were used for in vivo imaging by bioluminescence and epi fluorescence reflectance imaging (BLI & FRI) and as a source of embryonic fibroblast (MEF) for in vitro approaches. LucF, mPlum and endogenous Hsp70 mRNAs were transcribed simultaneously. The increase in mRNA was transient, peaking at 3 h and then returning to the basal level about 6 h after the thermal stimulations. The bioluminescent signal was transient and initiated with a 3 h delay versus mRNA expression. The onset of mPlum fluorescence was more delayed, increasing slowly up to 30 h after heat-shock and remaining for several days. This mouse allows for both bioluminescence imaging (BLI) and fluorescence reflectance imaging (FRI) of Hsp70 promoter activation showing an early and transient lucF activity and a retrospective and persistent mPlum fluorescence. This transgenic mouse will allow following the transient local induction of Hsp-70 promoter beyond its induction time-frame and relate into subsequent dynamic biological effects of the heat-shock response. PMID:24575340

  3. Antiproliferative activity of melanoidins isolated from heated potato fiber (potex) in glioma cell culture model.

    Science.gov (United States)

    Langner, Ewa; Nunes, Fernando M; Pozarowski, Piotr; Kandefer-Szerszeń, Martyna; Pierzynowski, Stefan G; Rzeski, Wojciech

    2011-03-23

    Potex constitutes a potato fiber preparation widely used as an ingredient to meat and bakery products which thermal treatment results in creation of new compounds. Melanoidins are high molecular weight brown end products of Maillard reaction, and few data presenting tumor cell growth inhibiting activity of melanoidins have been reported. Thus, in present study we utilized water extract of Potex roasted (180 °C for 2 h), whose chemical characterization revealed the presence of melanoidin complexes. Heated Potex extract inhibited C6 glioma cell proliferation in a dose-dependent manner measured by MTT method. High molecular weight components present in initial extract were responsible for stronger antiproliferative effect compared with low molecular weight fraction. Impaired MAPK (mitogen-activated protein kinase) and Akt signaling was found in cells treated with the extract. Moreover, flow cytometry analyses revealed the extract to induce G1/S arrest in glioma cells. Simultaneously, Western blot analysis showed elevated levels of p21 protein with concomitant decrease of cyclin D1. In conclusion, observed antiproliferative activity of melanoidins present in heated Potex was linked to disregulated MAPK and Akt signaling pathways, as well as to cell cycle cessation. These results suggest potential application of Potex preparation as a functional food ingredient and chemopreventive agent.

  4. Beta and gamma decay heat measurements between 0.1s-50,000s for neutron fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Progress report, March 1, 1993--January 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Schier, W.A.; Couchell, G.P.

    1994-06-01

    Decay heat measurements following the fast fission of {sup 238}U are well underway. The He-jet system and spectrometers were moved to the 1 MW research reactor to gain sufficient fast neutron flux for these measurements. On the Van de Graaff accelerator, the He-jet capillary has been shortened so that beta and gamma measurements following the thermal neutron fission of {sup 235}U could be made down to delay times near 0.1 s. Gamma-ray response functions are now well characterized for gamma energies up to 1.5 MeV for our large Nal spectrometer. Such response functions out to high energies are needed to extract energy distributions of our measured gamma spectra. The response function unfolding program, FERD-PC, has been operated successfully with trial spectra. Comparisons of individual fission products for {sup 235}U(n{sub th}f) with ENDF/B-VI at short delay times suggest several improvements to the data base particularly in production probabilities. The new data acquisition and data analysis systems have arrived and will soon be brought on line extending considerably the capabilities of our research group.

  5. High-resolution wind speed measurements using actively heated fiber optics

    Science.gov (United States)

    Sayde, Chadi; Thomas, Christoph K.; Wagner, James; Selker, John

    2015-11-01

    We present a novel technique to simultaneously measure wind speed (U) at thousands of locations continuously in time based on measurement of velocity-dependent heat transfer from a heated surface. Measuring temperature differences between paired passive and actively heated fiber-optic (AHFO) cables with a distributed temperature sensing system allowed estimation of U at over 2000 sections along the 230 m transect (resolution of 0.375 m and 5.5 s). The underlying concept is similar to that of a hot wire anemometer extended in space. The correlation coefficient between U measured by two colocated sonic anemometers and the AHFO were 0.91 during the day and 0.87 at night. The combination of classical passive and novel AHFO provides unprecedented dynamic observations of both air temperature and wind speed spanning 4 orders of magnitude in spatial scale (0.1-1000 m) while resolving individual turbulent motions, opening new opportunities for testing basic theories for near-surface geophysical flows.

  6. Adsorption of SO2 onto oxidized and heat-treated activated carbon fibers (ACFS)

    Science.gov (United States)

    Daley, M.A.; Mangun, C.L.; DeBarr, J.A.; Riha, S.; Lizzio, A.A.; Donnals, G.L.; Economy, J.

    1997-01-01

    A series of activated carbon fibers (ACFs) and heat-treated oxidized ACFs prepared from phenolic fiber precursors have been studied to elucidate the role of pore size, pore surface chemistry and pore volume for the adsorption of SO2 and its catalytic conversion to H2SO4. For untreated ACFs, the initial rate of SO2 adsorption from flue gas was shown to be inversely related to pore size. At longer times, the amount of SO2 adsorbed from flue gas was dependent on both the pore size and pore volume. Oxidation of the ACFs, using an aqueous oxidant, decreased their adsorption capacity for SO2 from flue gas due to a decrease in pore volume and repulsion of the SO2 from acidic surface groups. If these samples were heat-treated to desorb the oxygen containing function groups, the amount of SO2 adsorption increased. This increase in adsorption capacity was directly correlated to the amount of CO2 evolved during heat-treatment of the oxidized ACFs. The amount of SO2 adsorbed for these samples was related to the pore size, pore surface chemistry and pore volume. This analysis is explained in more detail in this paper. ?? 1997 Elsevier Science Ltd. All rights reserved.

  7. Characterization of Metarhizium species and varieties based on molecular analysis, heat tolerance and cold activity

    Science.gov (United States)

    Fernandes, E.K.K.; Keyser, C.A.; Chong, J.P.; Rangel, D.E.N.; Miller, M.P.; Roberts, D.W.

    2010-01-01

    Aims: The genetic relationships and conidial tolerances to high and low temperatures were determined for isolates of several Metarhizium species and varieties. Methods and Results: Molecular-based techniques [AFLP and rDNA (ITS1, ITS2 and 5??8S) gene sequencing] were used to characterize morphologically identified Metarhizium spp. isolates from a wide range of sources. Conidial suspensions of isolates were exposed to wet heat (45 ?? 0??2??C) and plated on potato dextrose agar plus yeast extract (PDAY) medium. After 8-h exposure, the isolates divided clearly into two groups: (i) all isolates of Metarhizium anisopliae var. anisopliae (Ma-an) and Metarhizium from the flavoviride complex (Mf) had virtually zero conidial relative germination (RG), (ii) Metarhizium anisopliae var. acridum (Ma-ac) isolates demonstrated high heat tolerance (c. 70-100% RG). Conidial suspensions also were plated on PDAY and incubated at 5??C for 15 days, during which time RGs for Ma-an and Ma-ac isolates were virtually zero, whereas the two Mf were highly cold active (100% RG). Conclusions: Heat and cold exposures can be used as rapid tools to tentatively identify some important Metarhizium species and varieties. Significance and Impact of the Study: Identification of Metarhizium spp. currently relies primarily on DNA-based methods; we suggest a simple temperature-based screen to quickly obtain tentative identification of isolates as to species or species complexes. ?? 2009 The Society for Applied Microbiology.

  8. Heat and mass transfer in unsteady rotating fluid flow with binary chemical reaction and activation energy.

    Directory of Open Access Journals (Sweden)

    Faiz G Awad

    Full Text Available In this study, the Spectral Relaxation Method (SRM is used to solve the coupled highly nonlinear system of partial differential equations due to an unsteady flow over a stretching surface in an incompressible rotating viscous fluid in presence of binary chemical reaction and Arrhenius activation energy. The velocity, temperature and concentration distributions as well as the skin-friction, heat and mass transfer coefficients have been obtained and discussed for various physical parametric values. The numerical results obtained by (SRM are then presented graphically and discussed to highlight the physical implications of the simulations.

  9. Heat and mass transfer in unsteady rotating fluid flow with binary chemical reaction and activation energy.

    Science.gov (United States)

    Awad, Faiz G; Motsa, Sandile; Khumalo, Melusi

    2014-01-01

    In this study, the Spectral Relaxation Method (SRM) is used to solve the coupled highly nonlinear system of partial differential equations due to an unsteady flow over a stretching surface in an incompressible rotating viscous fluid in presence of binary chemical reaction and Arrhenius activation energy. The velocity, temperature and concentration distributions as well as the skin-friction, heat and mass transfer coefficients have been obtained and discussed for various physical parametric values. The numerical results obtained by (SRM) are then presented graphically and discussed to highlight the physical implications of the simulations. PMID:25250830

  10. Simulation Research on Decay Heat Removal System in Primary Loop of Pool-type Sodium-cooled Fast Reactor%池式钠冷快堆事故余热排出系统一回路仿真研究

    Institute of Scientific and Technical Information of China (English)

    姜博; 张智刚; 于洋; 陈广亮; 张志俭

    2015-01-01

    池式钠冷快堆事故余热排出系统采用了非能动工作原理,依靠液态钠及空气的自然对流排出堆芯余热。为研究事故工况下余热排出系统一回路的换热能力,基于 FORTRAN 语言,建立堆芯单通道及盒间流模型,采用全隐二阶迎风差分格式及改进的欧拉法离散求解,对事故余热排出系统一回路系统进行数值模拟,并对全厂断电事故进行仿真计算验证。结果表明:该程序能较好地反映事故余热排出系统瞬态变化过程,并可达到超实时仿真。%T he decay heat removal system in pool‐type sodium‐cooled fast reactor (PSFR) is the passive safety system ,which depends on the natural circulation of sodium and air to keep the reactor coolant cooled .In order to verify the characteristics of the heat transfer of decay heat removal system in primary loop for accident condition ,the core single‐channel model and the flow between fuel assemblies model were established to simulate the decay heat removal system of primary loop and testify the program on station blackout accident , by using fully‐implicit second‐order upwind scheme and ameliorative Eular method to solve the equations based on FORTRAN .The calculation results show that the program could reflect the transient characteristics of the decay heat removal system ,and it could reach excess real‐time simulation .

  11. Low effective activation energies for oxygen release from metal oxides: evidence for mass-transfer limits at high heating rates.

    Science.gov (United States)

    Jian, Guoqiang; Zhou, Lei; Piekiel, Nicholas W; Zachariah, Michael R

    2014-06-01

    Oxygen release from metal oxides at high temperatures is relevant to many thermally activated chemical processes, including chemical-looping combustion, solar thermochemical cycles and energetic thermite reactions. In this study, we evaluated the thermal decomposition of nanosized metal oxides under rapid heating (~10(5) K s(-1)) with time-resolved mass spectrometry. We found that the effective activation-energy values that were obtained using the Flynn-Wall-Ozawa isoconversional method are much lower than the values found at low heating rates, indicating that oxygen transport might be rate-determining at a high heating rate. PMID:24619858

  12. Bubble chamber: Omega production and decay

    CERN Multimedia

    1973-01-01

    This image is taken from one of CERN's bubble chambers and shows the decay of a positive kaon in flight. The decay products of this kaon can be seen spiraling in the magnetic field of the chamber. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that has been heated to boiling point.

  13. Heat shock protein 70 regulates platelet integrin activation, granule secretion and aggregation.

    Science.gov (United States)

    Rigg, Rachel A; Healy, Laura D; Nowak, Marie S; Mallet, Jérémy; Thierheimer, Marisa L D; Pang, Jiaqing; McCarty, Owen J T; Aslan, Joseph E

    2016-04-01

    Molecular chaperones that support protein quality control, including heat shock protein 70 (Hsp70), participate in diverse aspects of cellular and physiological function. Recent studies have reported roles for specific chaperone activities in blood platelets in maintaining hemostasis; however, the functions of Hsp70 in platelet physiology remain uninvestigated. Here we characterize roles for Hsp70 activity in platelet activation and function. In vitro biochemical, microscopy, flow cytometry, and aggregometry assays of platelet function, as well as ex vivo analyses of platelet aggregate formation in whole blood under shear, were carried out under Hsp70-inhibited conditions. Inhibition of platelet Hsp70 blocked platelet aggregation and granule secretion in response to collagen-related peptide (CRP), which engages the immunoreceptor tyrosine-based activation motif-bearing collagen receptor glycoprotein VI (GPVI)-Fc receptor-γ chain complex. Hsp70 inhibition also reduced platelet integrin-αIIbβ3 activation downstream of GPVI, as Hsp70-inhibited platelets showed reduced PAC-1 and fibrinogen binding. Ex vivo, pharmacological inhibition of Hsp70 in human whole blood prevented the formation of platelet aggregates on collagen under shear. Biochemical studies supported a role for Hsp70 in maintaining the assembly of the linker for activation of T cells signalosome, which couples GPVI-initiated signaling to integrin activation, secretion, and platelet function. Together, our results suggest that Hsp70 regulates platelet activation and function by supporting linker for activation of T cells-associated signaling events downstream of platelet GPVI engagement, suggesting a role for Hsp70 in the intracellular organization of signaling systems that mediate platelet secretion, "inside-out" activation of platelet integrin-αIIbβ3, platelet-platelet aggregation, and, ultimately, hemostatic plug and thrombus formation.

  14. Effects of different heat treatments on lysozyme quantity and antimicrobial activity of jenny milk.

    Science.gov (United States)

    Cosentino, C; Labella, C; Elshafie, H S; Camele, I; Musto, M; Paolino, R; D'Adamo, C; Freschi, P

    2016-07-01

    Thermal treatments are used to improve milk microbial safety, shelf life, and biological activity of some of its components. However, thermal treatments can reduce the nutritional quality of milk, affecting the molecular structure of milk proteins, such as lysozyme, which is a very important milk component due to its antimicrobial effect against gram-positive bacteria. Jenny milk is characterized by high lysozyme content. For this reason, in the last few years, it has been used as an antimicrobial additive in dairy products as an alternative to hen egg white lysozyme, which can cause allergic reactions. This study aimed to investigate the effect of pasteurization and condensation on the concentration and antimicrobial activity of lysozyme in jenny milk. Furthermore, lysozyme quantity and activity were tested in raw and pasteurized milk after condensation at 40 and 20% of the initial volume. Reversed-phase HPLC was performed under fluorescence detection to monitor lysozyme in milk samples. We evaluated the antimicrobial activity of the tested milk against Bacillus megaterium, Bacillus mojavensis, Clavibacter michiganensis, Clostridium tyrobutyricum, Xanthomonas campestris, and Escherichia coli. Condensation and pasteurization did not affect the concentration or antimicrobial activity of lysozyme in jenny milk, except for B. mojaventis, which showed resistance to lysozyme in milk samples subjected to heat treatments. Moreover, lysozyme in jenny milk showed antimicrobial activity similar to synthetic antibiotics versus some gram-positive strains and also versus the gram-negative strain X. campestris. PMID:27157571

  15. Recurrent Heat Stroke in a Runner: Race Simulation Testing for Return to Activity.

    Science.gov (United States)

    Roberts, William O; Dorman, Jason C; Bergeron, Michael F

    2016-05-01

    Exertional heat stroke (EHS) occurs in distance runners and is a life-threatening condition. A 30-yr-old healthy recreational male distance runner (CR) collapsed at the 12-mile mark in two half marathon races 6 wk apart in fall 2009. In both episodes, CR was found on the ground confused, incoherent, sweaty, and warm to touch. The emergency medical team responded, and he was treated empirically for suspected EHS by cooling en route to the emergency department. In the emergency department, rectal temperatures were 40°C and 40.5°C for each episode, respectively. The first race start temperature was 16°C with 94% relative humidity (RH), and the second was 3°C, 75% RH. Heat tolerance test was within the normal range indicating low EHS risk. A race simulation test (environmental chamber, 25°C, 60% RH) at a treadmill pace of 10.5-12.9 km·h was stopped at 70 min coincident with a rectal temperature of 39.5°C. CR's body weight dropped 3.49 kg with an estimated sweat loss of 4.09 L and an estimated total sweat Na loss of 7610 mg. We recommended that he limit his runs to <1 h and replace salt and fluid during and (mostly) after activity, run with a partner, acclimate to heat before racing, and reduce his pace or stop at the first sign of symptoms. Race simulation testing should be considered in athletes with recurrent EHS to assist with the return-to-activity recommendation. PMID:26694842

  16. Bubble chamber: Omega production and decay

    CERN Multimedia

    1973-01-01

    This image is of real particle tracks taken from the CERN 2 m liquid hydrogen bubble chamber and shows the production and decay of a negative omega particle. A negative kaon enters the chamber which decays into many particles, including a negative omega that travels a short distance before decaying into more particles. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  17. Catharanthus roseus mitogen-activated protein kinase 3 confers UV and heat tolerance to Saccharomyces cerevisiae

    Science.gov (United States)

    Raina, Susheel Kumar; Wankhede, Dhammaprakash Pandhari; Sinha, Alok Krishna

    2013-01-01

    Catharanthus roseus is an important source of pharmaceutically important Monoterpenoid Indole Alkaloids (MIAs). Accumulation of many of the MIAs is induced in response to abiotic stresses such as wound, ultra violet (UV) irradiations, etc. Recently, we have demonstrated a possible role of CrMPK3, a C. roseus mitogen-activated protein kinase in stress-induced accumulation of a few MIAs. Here, we extend our findings using Saccharomyces cerevisiae to investigate the role of CrMPK3 in giving tolerance to abiotic stresses. Yeast cells transformed with CrMPK3 was found to show enhanced tolerance to UV and heat stress. Comparison of CrMPK3 and SLT2, a MAPK from yeast shows high-sequence identity particularly at conserved domains. Additionally, heat stress is also shown to activate a 43 kDa MAP kinase, possibly CrMPK3 in C. roseus leaves. These findings indicate the role of CrMPK3 in stress-induced MIA accumulation as well as in stress tolerance. PMID:23221751

  18. Anti-cancer activities of pH- or heat-modified pectin

    Directory of Open Access Journals (Sweden)

    Lionel eLeclere

    2013-10-01

    Full Text Available Despite enormous efforts that have been made in the search for novel drugs and treatments, cancer continues to be a major public health problem. Moreover, the emergence of resistance to cancer chemotherapy often prevents complete remission. Researchers have thus turned to natural products mainly from plant origin to circumvent resistance. Pectin and pH- or heat-modified pectin have demonstrated chemopreventive and antitumoral activities against some aggressive and recurrent cancers. The focus of this review is to describe how pectin and modified pectin display these activities and what are the possible underlying mechanisms. The failure of conventional chemotherapy to reduce mortality as well as serious side effects makes natural products, such as pectin-derived products, ideal candidates for exerting synergism in combination with conventional anticancer drugs.

  19. AGN activity and IGM heating in fossil cluster RX J1416.4+2315

    CERN Document Server

    Miraghaei, H; Sengupta, C; Raychaudhury, S; Jetha, N N; Abbassi, S

    2015-01-01

    We study Active Galactic Nucleus (AGN) activity in the fossil galaxy cluster, RX J1416.4+2315. Radio observations were carried out using Giant Metrewave Radio Telescope (GMRT) at two frequencies, 1420 MHz and 610 MHz. A weak radio lobe that extends from the central nucleus is detected in 610 MHz map. Assuming the radio lobe originated from the central AGN, we show the energy injection into the Inter Galactic Medium (IGM) is only sufficient to heat up the central 50 kpc within the cluster core, while the cooling radius is larger ( $\\sim$ 130 kpc). In the hardness ratio map, three low energy cavities have been identified. No radio emission is detected for these regions. We evaluated the power required to inflate the cavities and showed that the total energy budget is sufficient to offset the radiative cooling. We showed that the initial conditions would change the results remarkably. Furthermore, efficiency of Bondi accretion to power the AGN has been estimated.

  20. AGN ACTIVITY AND IGM HEATING IN THE FOSSIL CLUSTER RX J1416.4+2315

    Energy Technology Data Exchange (ETDEWEB)

    Miraghaei, H.; Khosroshahi, H. G.; Abbassi, S. [School of Astronomy, Institute for Research in Fundamental Sciences, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Sengupta, C. [Korea Astronomy and Space Science Institute, 776, Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Raychaudhury, S. [Department of Physics, Presidency University, 86/1 College Street, 700 073 Kolkata (India); Jetha, N. N., E-mail: halime@ipm.ir [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35805 (United States)

    2015-12-15

    We study active galactic nucleus (AGN) activity in the fossil galaxy cluster RX J1416.4+2315. Radio observations were carried out using the Giant Metrewave Radio Telescope at two frequencies, 1420 and 610 MHz. A weak radio lobe that extends from the central nucleus is detected in the 610 MHz map. Assuming the radio lobe originated from the central AGN, we show that the energy injection into the intergalactic medium is only sufficient to heat up the central 50 kpc within the cluster core, while the cooling radius is larger (∼130 kpc). In the hardness ratio map, three low energy cavities have been identified. No radio emission is detected for these regions. We evaluated the power required to inflate the cavities and showed that the total energy budget is sufficient to offset the radiative cooling. We showed that the initial conditions would change the results remarkably. Furthermore, the efficiency of the Bondi accretion in powering the AGN has been estimated.

  1. Heat Transfer Measurements with Surface Mounted Foil-Sensors in an Active Mode: A Comprehensive Review and a New Design

    Directory of Open Access Journals (Sweden)

    Heinz Herwig

    2009-04-01

    Full Text Available A comprehensive review of film-sensors shows that they are primarily operated in a passive mode, i.e. without being actively heated to an extent, whereby they create a heat transfer situation on their own. Only when these sensors are used for wall shear stress measurements, the detection of laminar/turbulent transition, or the measurement of certain flow velocities, they are operated in an active mode, i.e. heated by an electrical current (after an appropriate calibration. In our study we demonstrate how these R(T-based sensors (temperature dependence of the electrical resistance R can also be applied in an active mode for heat transfer measurements. These measurements can be made on cold, unheated bodies, provided certain requirements with respect to the flow field are fulfilled. Our new sensors are laminated nickel- and polyimide-foils manufactured with a special technology, which is also described in detail.

  2. Thermodynamic analysis of active heat storage-release associated with heat pump heating system in greenhouse%温室主动蓄放热-热泵联合加温系统热力学分析

    Institute of Scientific and Technical Information of China (English)

    孙维拓; 张义; 杨其长; 方慧; 卢威; 胡永逵

    2014-01-01

    主动蓄放热-热泵联合加温系统加温和节能效果显著,在温室加温领域应用前景广阔,但系统技术参数及工艺仍有待优化。该文通过对系统进行能量平衡和可用能(Exergy)分析,得出系统及各组件的性能系数、可用能损失、损失比和可用能效率,以此为依据对系统进行性能评价和优化。试验结果表明:系统平均1d中集热和保温阶段可用能损失总量为9.77×104 kJ,可用能效率为48.7%;可用能损失最大、可用能效率最低的组件是主动蓄放热装置,其次是热泵装置、循环水泵和蓄热水箱,其可用能损失比分别为78.7%、8.3%、7.7%、5.3%,可用能效率分别为25.6%、38.3%、75.0%、88.2%。就整个系统而言,最需要进行技术优化的是主动蓄放热装置与热泵装置,可用能损失主要由有限温差传热引起,降低传热温差、减少有限温差传热过程以及改进生产工艺是优化的重点。试验期间系统的集热效率为89.0%~100.5%,热泵装置制热性能系数(coefficient of performance,COPHp)达5.48~6.08,性能远远高于传统太阳能热水系统以及水、地源热泵。该研究为温室加温系统性能评价和优化设计提供思路。%Active heat storage-release associated with heat pump heating system (AHSRHPS) has remarkable heating and energy-saving effects, which use the same principle as an indirect-expansion solar heat pump, while allowing the technical parameters and processes to continue to improve. The system in this study was designed and constructed in the experimental glass greenhouse at the Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences. The main objective was to investigate performance evaluation and thermoeconomic analysis of AHSRHPS for greenhouse heating in the winter. This included the exergy loss of the system and components, defining the specific locations and

  3. Non Destructive Testing by active infrared thermography coupled with shearography under same optical heat excitation

    Science.gov (United States)

    Theroux, Louis-Daniel; Dumoulin, Jean; Maldague, Xavier

    2014-05-01

    As infrastructures are aging, the evaluation of their health is becoming crucial. To do so, numerous Non Destructive Testing (NDT) methods are available. Among them, thermal shearography and active infrared thermography represent two full field and contactless methods for surface inspection. The synchronized use of both methods presents multiples advantages. Most importantly, both NDT are based on different material properties. Thermography depend on the thermal properties and shearography on the mechanical properties. The cross-correlation of both methods result in a more accurate and exact detection of the defects. For real site application, the simultaneous use of both methods is simplified due to the fact that the excitation method (thermal) is the same. Active infrared thermography is the measure of the temperature by an infrared camera of a surface subjected to heat flux. Observation of the variation of temperature in function of time reveal the presence of defects. On the other hand, shearography is a measure of out-of-plane surface displacement. This displacement is caused by the application of a strain on the surface which (in our case) take the form of a temperature gradient inducing a thermal stress To measure the resulting out-of-plane displacement, shearography exploit the relation between the phase difference and the optical path length. The phase difference is measured by the observation of the interference between two coherent light beam projected on the surface. This interference is due to change in optical path length as the surface is deformed [1]. A series of experimentation have been conducted in laboratory with various sample of concrete reinforced with CFRP materials. Results obtained reveal that with both methods it was possible to detect defects in the gluing. An infrared lamp radiating was used as the active heat source. This is necessary if measurements with shearography are to be made during the heating process. A heating lamp in the

  4. Plasma hyperosmolality elevates the internal temperature threshold for active thermoregulatory vasodilation during heat stress in humans.

    Science.gov (United States)

    Shibasaki, Manabu; Aoki, Ken; Morimoto, Keiko; Johnson, John M; Takamata, Akira

    2009-12-01

    Plasma hyperosmolality delays the response in skin blood flow to heat stress by elevating the internal temperature threshold for cutaneous vasodilation. This elevation could be because of a delayed onset of cutaneous active vasodilation and/or to persistent cutaneous active vasoconstriction. Seven healthy men were infused with either hypertonic (3% NaCl) or isotonic (0.9% NaCl) saline and passively heated by immersing their lower legs in 42 degrees C water for 60 min (room temperature, 28 degrees C; relative humidity, 40%). Skin blood flow was monitored via laser-Doppler flowmetry at sites pretreated with bretylium tosylate (BT) to block sympathetic vasoconstriction selectively and at adjacent control sites. Plasma osmolality was increased by approximately 13 mosmol/kgH(2)O following hypertonic saline infusion and was unchanged following isotonic saline infusion. The esophageal temperature (T(es)) threshold for cutaneous vasodilation at untreated sites was significantly elevated in the hyperosmotic state (37.73 +/- 0.11 degrees C) relative to the isosmotic state (36.63 +/- 0.12 degrees C, P < 0.001). A similar elevation of the T(es) threshold for cutaneous vasodilation was observed between osmotic conditions at the BT-treated sites (37.74 +/- 0.18 vs. 36.67 +/- 0.07 degrees C, P < 0.001) as well as sweating. These results suggest that the hyperosmotically induced elevation of the internal temperature threshold for cutaneous vasodilation is due primarily to an elevation in the internal temperature threshold for the onset of active vasodilation, and not to an enhancement of vasoconstrictor activity. PMID:19812357

  5. Heat shock inhibits. alpha. -amylase synthesis in barley aleurone without inhibiting the activity of endoplasmic reticulum marker enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Sticher, L.; Biswas, A.K.; Bush, D.S.; Jones, R.L. (Univ. of California, Berkeley (USA))

    1990-02-01

    The effects of heat shock on the synthesis of {alpha}-amylase and on the membranes of the endoplasmic reticulum (ER) of barley (Hordeum vulgare) aleurone were studied. Heat shock, imposed by raising the temperature of incubation from 25{degree}C to 40{degree}C for 3 hours, inhibits the accumulation of {alpha}-amylase and other proteins in the incubation medium of barley aleurone layers treated with gibberellic acid and Ca{sup 2+}. When ER is isolated from heat-shocked aleurone layers, less newly synthesized {alpha}-amylase is found associated with this membrane system. ER membranes, as indicated by the activities of NADH cytochrome c reductase and ATP-dependent Ca{sup 2+} transport, are not destroyed by heat stress, however. Although heat shock did not reduce the activity of ER membrane marker enzymes, it altered the buoyant density of these membranes. Whereas ER from control tissue showed a peak of marker enzyme activity at 27% to 28% sucrose (1.113-1.120 grams per cubic centimeter), ER from heat-shocked tissue peaked at 30% to 32% sucrose (1.127-1.137 grams per cubic centimeter). The synthesis of a group of proteins designated as heat-shock proteins (HSPs) was stimulated by heat shock. These HSPs were localized to different compartments of the aleurone cell. Several proteins ranging from 15 to 30 kilodaltons were found in the ER and the mitochondrial/plasma membrane fractions of heat-shocked cells, but none of the HSPs accumulated in the incubation medium of heat-shocked aleurone layers.

  6. Impacts of decaying eastern and central Pacific El Niños on tropical cyclone activities over the western North Pacific in summer

    Science.gov (United States)

    Yang, Yuxing; Xie, Ruihuang; Wang, Faming; Huang, Fei

    2016-07-01

    We investigate the influences of the decaying eastern Pacific El Niño (EP-El Niño) and central Pacific El Niño (CP-El Niño) on tropical cyclone (TC) activities in the western North Pacific (WNP) during July, August, and September (JAS). During this period, TC geneses and tracks are reduced in the central and eastern WNP. However, TC tracks reaching the Philippines increase, and more TC geneses appear west of 145°E during EP-El Niño. During CP-El Niño, tracks reaching the South China Sea (SCS) and southeast coast of China increase, and positive anomalies of TC genesis are found in the southern part of the central WNP and southern SCS. It is possible that the different variations of the anomalous anticyclone over east of the Philippines in the WNP induced by El Niños are instrumental to the different TC variations in the two types of decaying El Niños during JAS. Compared with EP-El Niño, strengthening and northward expansion of the anomalous anticyclone during CP-El Niño cause a westward shift of the western Pacific subtropical high in summer, which is responsible for more westward TC tracks over the SCS and southeast coast of China. This northward expansion can cause the center of suppressed TC geneses in the central WNP to migrate further north during CP-El Niño. A decreased magnitude of vertical shear dominates the southern part of the central WNP and southern SCS, which enhances TC formation in these regions during CP-El Niño.

  7. Development of a protease activity assay using heat-sensitive Tus-GFP fusion protein substrates.

    Science.gov (United States)

    Askin, Samuel P; Morin, Isabelle; Schaeffer, Patrick M

    2011-08-15

    Proteases are implicated in various diseases and several have been identified as potential drug targets or biomarkers. As a result, protease activity assays that can be performed in high throughput are essential for the screening of inhibitors in drug discovery programs. Here we describe the development of a simple, general method for the characterization of protease activity and its use for inhibitor screening. GFP was genetically fused to a comparatively unstable Tus protein through an interdomain linker containing a specially designed protease site, which can be proteolyzed. When this Tus-GFP fusion protein substrate is proteolyzed it releases GFP, which remains in solution after a short heat denaturation and centrifugation step used to eliminate uncleaved Tus-GFP. Thus, the increase in GFP fluorescence is directly proportional to protease activity. We validated the protease activity assay with three different proteases, i.e., trypsin, caspase 3, and neutrophil elastase, and demonstrated that it can be used to determine protease activity and the effect of inhibitors with small sample volumes in just a few simple steps using a fluorescence plate reader.

  8. Heat Shock Protein-70 Expression in Vitiligo and its Relation to the Disease Activity

    Science.gov (United States)

    Doss, Reham William; El-Rifaie, Abdel-Aziz A; Abdel-Wahab, Amr M; Gohary, Yasser M; Rashed, Laila A

    2016-01-01

    Background: Vitiligo is a progressive depigmenting disorder characterized by the loss of functional melanocytes from the epidermis. The etiopathogenesis of vitiligo is still unclear. Heat shock proteins (HSPs) are prime candidates to connect stress to the skin. HSPs were found to be implicated in autoimmune diseases such as rheumatoid arthritis and other skin disorders as psoriasis. Aim and Objectives: The aim of this study was to map the level of HSP-70 in vitiligo lesions to declare its role in the pathogenesis and activity of vitiligo. Materials and Methods: The study included thirty patients with vitiligo and 30 age- and sex-matched healthy controls. Vitiligo patients were divided as regards to the disease activity into highly active, moderately active, and inactive vitiligo groups. Skin biopsies were taken from the lesional and nonlesional skin of patients and from the normal skin of the controls. HSP-70 messenger RNA (mRNA) expression was estimated using quantitative real-time polymerase chain reaction. Results: Our analysis revealed a significantly higher expression of HSP-70 mRNA in lesional skin biopsies from vitiligo patients compared to nonlesional skin biopsies from vitiligo patients (P vitiligo showed higher mean HSP-70 level compared to those with inactive disease. Conclusions: HSP-70 plays a role in the pathogenesis of vitiligo and may enhance the immune response in active disease.

  9. Research programme 'Active Solar Energy Use - Solar Heating and Heat Storage'. Activities and projects 2003; Programme 'Solaire actif - Chaleur et Stockage de chaleur'. Activites et projets en 2003

    Energy Technology Data Exchange (ETDEWEB)

    Hadorn, J.-C. [Base Consultants, Geneva (Switzerland); Renaud, P. [Planair SA, La Sagne (Switzerland)

    2003-07-01

    In this report by the research, development and demonstration (RD+D) programme coordinators the objectives, activities and main results in the area of solar heating and heat storage in Switzerland are presented for 2003. In a stagnating market environment the strategy of the Swiss Federal Office of Energy mainly consists in improving the quality and durability of solar collectors and materials, optimizing combisystems for space heating and domestic hot water preparation, searching for storage systems with a higher energy storage density than in the case of sensible heat storage in water, developing coloured solar collectors for more architectonic freedom, and finalizing a seasonal heat storage project for 100 dwellings to demonstrate the feasibility of solar fractions larger than 50% in apartment houses. Support was granted to the Swiss Testing Facility SPF in Rapperswil as in previous years; SPF was the first European testing institute to perform solar collector labeling according to the new rules of the 'Solar Keymark', introduced in cooperation with the European Committee for Standardization CEN. Several 2003 projects were conducted within the framework of the Solar Heating and Cooling Programme of the International Energy Agency IEA. Computerized simulation tools were improved. With the aim of jointly producing high-temperature heat and electric power a solar installation including a concentrating collector and a thermodynamic machine based on a Rankine cycle is still being developed. Seasonal underground heat storage was studied in detail by means of a validated computer simulation programme. Design guidelines were obtained for such a storage used in the summer time for cooling and in the winter time for space heating via a heat pump: depending on the ratio 'summer cooling / winter heating', cooling requires a cooling machine, or direct cooling without such a machine is possible. The report ends up with the list of all supported RD

  10. Modulating the RNA processing and decay by the exosome: altering Rrp44/Dis3 activity and end-product.

    Directory of Open Access Journals (Sweden)

    Filipa P Reis

    Full Text Available In eukaryotes, the exosome plays a central role in RNA maturation, turnover, and quality control. In Saccharomyces cerevisiae, the core exosome is composed of nine catalytically inactive subunits constituting a ring structure and the active nuclease Rrp44, also known as Dis3. Rrp44 is a member of the ribonuclease II superfamily of exoribonucleases which include RNase R, Dis3L1 and Dis3L2. In this work we have functionally characterized three residues located in the highly conserved RNB catalytic domain of Rrp44: Y595, Q892 and G895. To address their precise role in Rrp44 activity, we have constructed Rrp44 mutants and compared their activity to the wild-type Rrp44. When we mutated residue Q892 and tested its activity in vitro, the enzyme became slightly more active. We also showed that when we mutated Y595, the final degradation product of Rrp44 changed from 4 to 5 nucleotides. This result confirms that this residue is responsible for the stacking of the RNA substrate in the catalytic cavity, as was predicted from the structure of Rrp44. Furthermore, we also show that a strain with a mutation in this residue has a growth defect and affects RNA processing and degradation. These results lead us to hypothesize that this residue has an important biological role. Molecular dynamics modeling of these Rrp44 mutants and the wild-type enzyme showed changes that extended beyond the mutated residues and helped to explain these results.

  11. Results of fission products β decay properties measurement performed with a total absorption spectrometer

    Directory of Open Access Journals (Sweden)

    Zakari-Issoufou A.-A.

    2014-03-01

    Full Text Available β-decay properties of fission products are very important for applied reactor physics, for instance to estimate the decay heat released immediately after the reactor shutdown and to estimate the ν¯$\\bar \

  12. Activity of heat shock genes' promoters in thermally contrasting animal species.

    Science.gov (United States)

    Astakhova, Lyubov N; Zatsepina, Olga G; Funikov, Sergei Yu; Zelentsova, Elena S; Schostak, Natalia G; Orishchenko, Konstantin E; Evgen'ev, Michael B; Garbuz, David G

    2015-01-01

    Heat shock gene promoters represent a highly conserved and universal system for the rapid induction of transcription after various stressful stimuli. We chose pairs of mammalian and insect species that significantly differ in their thermoresistance and constitutive levels of Hsp70 to compare hsp promoter strength under normal conditions and after heat shock (HS). The first pair includes the HSPA1 gene promoter of camel (Camelus dromedarius) and humans. It was demonstrated that the camel HSPA1A and HSPA1L promoters function normally in vitro in human cell cultures and exceed the strength of orthologous human promoters under basal conditions. We used the same in vitro assay for Drosophila melanogaster Schneider-2 (S2) cells to compare the activity of the hsp70 and hsp83 promoters of the second species pair represented by Diptera, i.e., Stratiomys singularior and D. melanogaster, which dramatically differ in thermoresistance and the pattern of Hsp70 accumulation. Promoter strength was also monitored in vivo in D. melanogaster strains transformed with constructs containing the S. singularior hsp70 ORF driven either by its own promoter or an orthologous promoter from the D. melanogaster hsp70Aa gene. Analysis revealed low S. singularior hsp70 promoter activity in vitro and in vivo under basal conditions and after HS in comparison with the endogenous promoter in D. melanogaster cells, which correlates with the absence of canonical GAGA elements in the promoters of the former species. Indeed, the insertion of GAGA elements into the S. singularior hsp70 regulatory region resulted in a dramatic increase in promoter activity in vitro but only modestly enhanced the promoter strength in the larvae of the transformed strains. In contrast with hsp70 promoters, hsp83 promoters from both of the studied Diptera species demonstrated high conservation and universality.

  13. Cooling vest worn during active warm-up improves 5-km run performance in the heat.

    Science.gov (United States)

    Arngrïmsson, Sigurbjörn A; Petitt, Darby S; Stueck, Matthew G; Jorgensen, Dennis K; Cureton, Kirk J

    2004-05-01

    We investigated whether a cooling vest worn during an active warm-up enhances 5-km run time in the heat. Seventeen competitive runners (9 men, maximal oxygen uptake = 66.7 +/- 5.9 ml x kg(-1) x min(-1); 8 women, maximal oxygen uptake = 58.0 +/- 3.2 ml x kg(-1) x min(-1)) completed two simulated 5-km runs on a treadmill after a 38-min active warm-up during which they wore either a T-shirt (C) or a vest filled with ice (V) in a hot, humid environment (32 degrees C, 50% relative humidity). Wearing the cooling vest during warm-up significantly (P run, esophageal, rectal, mean skin, and mean body temperatures averaged 0.3, 0.2, 1.8, and 0.4 degrees C lower; HR averaged 11 beats/min lower; and perception of thermal discomfort (5-point scale) averaged 0.6 point lower in V than C. Most of these differences were eliminated during the first 3.2 km of the run, and these variables were not different at the end. The 5-km run time was significantly lower (P faster pace most evident during the last two-thirds of the run. We conclude that a cooling vest worn during active warm-up by track athletes enhances 5-km run performance in the heat. Reduced thermal and cardiovascular strain and perception of thermal discomfort in the early portion of the run appear to permit a faster pace later in the run.

  14. A sexual dimorphism influences bicyclol-induced hepatic heat shock factor 1 activation and hepatoprotection.

    Science.gov (United States)

    Chen, Xiaosong; Zhang, Jianjian; Han, Conghui; Dai, Huijuan; Kong, Xianming; Xu, Longmei; Xia, Qiang; Zhang, Ming; Zhang, Jianjun

    2015-07-01

    Bicyclol [4,4'-dimethoxy-5,6,5',6'-bis(methylenedioxy)-2-hydroxy-methyl-2'-methoxycarbonyl biphenyl] is a synthetic hepatoprotectant widely used in clinical practice, but resistance to this treatment is often observed. We found that the hepatoprotective effect of bicyclol was greatly compromised in female and castrated male mice. This study was to dissect the molecular basis behind the sex difference, which might underlie the clinical uncertainty. We compared bicyclol-induced hepatoprotection between male and female mice using acute liver damage models. Inducible knockout by the Cre/loxp system was used to decipher the role of heat shock transcription factor 1 (HSF1). Functional experiments, western blot, and histopathological analysis were used to determine the key causative factors which might antagonize bicyclol in female livers. HSF1 activation and heat shock protein 70 (Hsp70) expression, which were responsible for bicyclol-induced hepatoprotection, were compromised in female and castrated male livers. Compromised HSF1 activation was a result of HSF1 phosphorylation at serine 303, which was catalyzed by glycogen synthase kinase 3β (GSK3β). Testosterone was necessary for bicyclol to inhibit hepatic GSK3β activity. Administration of testosterone or GSK3β inhibitors restored bicyclol-induced protection in females. Bicyclol induces sex-specific hepatoprotection based on a sex-specific HSF1/Hsp70 response, in which testosterone and GSK3β play key roles. Because a lot of patients suffering from liver diseases have very low testosterone levels, our results give a possible explanation for the clinical variation in bicyclol-induced hepatoprotection, as well as practicable solutions to improve the effect of bicyclol. PMID:25901028

  15. Coatings of active and heat-resistant cobalt-aluminium xerogel catalysts.

    Science.gov (United States)

    Schubert, Miriam; Schubert, Lennart; Thomé, Andreas; Kiewidt, Lars; Rosebrock, Christopher; Thöming, Jorg; Roessner, Frank; Bäumer, Marcus

    2016-09-01

    The application of catalytically coated metallic foams in catalytic processes has a high potential for exothermic catalytic reactions such as CO2 methanation or Fischer-Tropsch synthesis due to good heat conductivity, improved turbulent flow properties and high catalyst efficiencies. But the preparation of homogenous catalyst coats without pore blocking is challenging with conventional wash coating techniques. Here, we report on a stable and additive free colloidal CoAlOOH suspension (sol) for the preparation of catalytically active Co/Al2O3 xerogel catalysts and coatings. Powders with 18wt% Co3O4 prepared from this additive free synthesis route show a catalytic activity in Fischer-Tropsch synthesis and CO2 methanation which is similar to a catalyst prepared by incipient wetness impregnation (IWI) after activating the material under flowing hydrogen at 430°C. Yet, the xerogel catalyst exhibits a much higher thermal stability as compared to the IWI catalyst, as demonstrated in catalytic tests after different heat agings between 430°C and 580°C. It was also found that the addition of polyethylene glycol (PEG) to the sol influences the catalytic properties of the formed xerogels negatively. Only non-reducible cobalt spinels were formed from a CoAlOOH sol with 20wt% PEG. Metallic foams with pores sizes between 450 and 1200μm were coated with the additive free CoAlOOH sol, which resulted in homogenous xerogel layers. First catalytic tests of the coated metal foams (1200μm) showed good performance in CO2 methanation. PMID:27240245

  16. Heat shock protein-70 expression in vitiligo and its relation to the disease activity

    Directory of Open Access Journals (Sweden)

    Reham William Doss

    2016-01-01

    Full Text Available Background: Vitiligo is a progressive depigmenting disorder characterized by the loss of functional melanocytes from the epidermis. The etiopathogenesis of vitiligo is still unclear. Heat shock proteins (HSPs are prime candidates to connect stress to the skin. HSPs were found to be implicated in autoimmune diseases such as rheumatoid arthritis and other skin disorders as psoriasis. Aim and Objectives: The aim of this study was to map the level of HSP-70 in vitiligo lesions to declare its role in the pathogenesis and activity of vitiligo. Materials and Methods: The study included thirty patients with vitiligo and 30 age- and sex-matched healthy controls. Vitiligo patients were divided as regards to the disease activity into highly active, moderately active, and inactive vitiligo groups. Skin biopsies were taken from the lesional and nonlesional skin of patients and from the normal skin of the controls. HSP-70 messenger RNA (mRNA expression was estimated using quantitative real-time polymerase chain reaction. Results: Our analysis revealed a significantly higher expression of HSP-70 mRNA in lesional skin biopsies from vitiligo patients compared to nonlesional skin biopsies from vitiligo patients (P < 0.001 and compared to skin biopsies from healthy controls (P < 0.001. The level of HSP-70 was not found to be correlated with age, sex, or disease duration. The expression of HSP-70 was correlated with the disease activity and patients with active vitiligo showed higher mean HSP-70 level compared to those with inactive disease. Conclusions: HSP-70 plays a role in the pathogenesis of vitiligo and may enhance the immune response in active disease.

  17. Horizontal flow fields in and around a small active region-- The transition period between flux emergence and decay

    CERN Document Server

    Verma, M; Balthasar, H; Kuckein, C; Manrique, S J González; Sobotka, M; González, N Bello; Hoch, S; Diercke, A; Kummerow, P; Berkefeld, T; Collados, M; Feller, A; Hofmann, A; Kneer, F; Lagg, A; Löhner-Böttcher, J; Nicklas, H; Yabar, A Pastor; Schlichenmaier, R; Schmidt, D; Schmidt, W; Schubert, M; Sigwarth, M; Solanki, S K; Soltau, D; Staude, J; Strassmeier, K G; Volkmer, R; von der Lühe, O; Waldmann, T

    2016-01-01

    Aims. Combining high-resolution and synoptic observations aims to provide a comprehensive description of flux emergence at photospheric level and of the growth process that eventually leads to a mature active region. Methods. Small active region NOAA 12118 was observed on 2014 July 18 with the 1.5-meter GREGOR solar telescope on 2014 July 18. High-resolution time-series of blue continuum and G-band images acquired in the blue imaging channel (BIC) of the GREGOR Fabry-P\\'erot Interferometer (GFPI) were complemented by LOS magnetograms and continuum images obtained with the HMI onboard the SDO. Horizontal proper motions and horizontal plasma velocities were computed with local correlation tracking (LCT) and the differential affine velocity estimator, respectively. Morphological image processing was employed to measure the photometric/magnetic area, magnetic flux, and the separation profile of the EFR during its evolution. Results. The computed growth rates for photometric area, magnetic area, and magnetic flux ...

  18. Estimation of the activity and isotopic composition of the fuel elements of the reactor in decaying; Estimacion de la actividad y composicion isotopica de los elementos combustibles del reactor en decaimiento

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2001-03-15

    At the present time its are had 59 fuel elements, 3 control bars with follower and 2 instrumented irradiated fuels that its are decaying in the pool of the reactor. The burnt one that its have these fuels is not uniform, the quantity of U-235 that contain at the moment it varies between 33.5 g up to 35.2 and its have a decay of at least 12 years. The burnt of the fuels was obtained with the CREMAT code, this burnt was takes like base to estimate the current isotopic inventory and the activity of the same ones using the ORIGEN2 code. (Author)

  19. Thermodynamic assessment of active cooling/heating methods for lithium-ion batteries of electric vehicles in extreme conditions

    International Nuclear Information System (INIS)

    The battery cooling/heating with active methods is required for EVs (electric vehicles) in the extreme temperature conditions. This work presents a new active battery cooling/heating method based on PCS (phase change slurry) cycle. Two typical often used active cooling/heating methods so-called the direct cabin air blow and refrigerant circulation are also illustrated in detail. The thermodynamic assessment is conducted on these battery active cooling/heating methods with both of 1st Law and 2nd Law analysis. The variations of extra thermal load to the vehicle air-conditioning system are investigated as changes of ambient temperature, humidity and thermal load for the direct cabin air blow method. The simulation results show that the direct cabin air blow method causes more extra thermal load to the air-conditioning system without considering the cabin ventilation effect. The PCS cycle method performs higher exergy efficiency than that of using refrigerant circulation method. - Highlights: • An active EV battery cooling/heating method based on PCS cycle is proposed. • Thermodynamic assessments are performed for the proposed methods. • The sensitivities of operation conditions to the methods are investigated

  20. Chalcones from Angelica keiskei: Evaluation of Their Heat Shock Protein Inducing Activities.

    Science.gov (United States)

    Kil, Yun-Seo; Choi, Seul-Ki; Lee, Yun-Sil; Jafari, Mahtab; Seo, Eun-Kyoung

    2015-10-23

    Five new chalcones, 4,2',4'-trihydroxy-3'-[(2E,5E)-7-methoxy-3,7-dimethyl-2,5-octadienyl]chalcone (1), (±)-4,2',4'-trihydroxy-3'-[(2E)-6-hydroxy-7-methoxy-3,7-dimethyl-2-octenyl]chalcone (2), 4,2',4'-trihydroxy-3'-[(2E)-3-methyl-5-(1,3-dioxolan-2-yl)-2-pentenyl]chalcone (3), 2',3'-furano-4-hydroxy-4'-methoxychalcone (4), and (±)-4-hydroxy-2',3'-(2,3-dihydro-2-methoxyfurano)-4'-methoxychalcone (5), were isolated from the aerial parts of Angelica keiskei Koidzumi together with eight known chalcones, 6-13, which were identified as (±)-4,2',4'-trihydroxy-3'-[(6E)-2-hydroxy-7-methyl-3-methylene-6-octenyl]chalcone (6), xanthoangelol (7), xanthoangelol F (8), xanthoangelol G (9), 4-hydroxyderricin (10), xanthoangelol D (11), xanthoangelol E (12), and xanthoangelol H (13), respectively. Chalcones 1-13 were evaluated for their promoter activity on heat shock protein 25 (hsp25, murine form of human hsp27). Compounds 1 and 6 activated the hsp25 promoter by 21.9- and 29.2-fold of untreated control at 10 μM, respectively. Further protein expression patterns of heat shock factor 1 (HSF1), HSP70, and HSP27 by 1 and 6 were examined. Compound 6 increased the expression of HSF1, HSP70, and HSP27 by 4.3-, 1.5-, and 4.6-fold of untreated control, respectively, without any significant cellular cytotoxicities, whereas 1 did not induce any expression of these proteins. As a result, 6 seems to be a prospective HSP inducer.

  1. Regional Heat Sources and the Active and Break Phases of Boreal Summer Intraseasonal Variability

    Energy Technology Data Exchange (ETDEWEB)

    Annamalai, H; Sperber, K R

    2003-12-15

    The boreal summer intraseasonal variability (BSISV) associated with the 30-50 day mode is represented by the co-existence of three components, poleward propagation of convection over the Indian and tropical west Pacific longitudes and eastward propagation along the equator. The hypothesis that the three components influence each other has been investigated using observed OLR, NCEP-NCAR reanalysis, and solutions from an idealized linear model. The null hypothesis is that the three components are mutually independent. Cyclostationary EOF (CsEOF) analysis is applied on filtered OLR to extract the life-cycle of the BSISV. The dominant mode of CsEOF is significantly tied to observed rainfall over the Indian subcontinent. The components of the heating patterns from CsEOF analysis serve as prescribed forcings for the linear model. This allows us to ascertain which heat sources and sinks are instrumental in driving the large-scale monsoon circulation during the BSISV life-cycle. We identify three new findings: (1) the circulation anomalies that develop as a Rossby wave response to suppressed convection over the equatorial Indian Ocean associated with the previous break phase of the BSISV precondition the ocean-atmosphere system in the western Indian Ocean and trigger the next active phase of the BSISV, (2) the development of convection over the tropical west Pacific forces descent anomalies to the west. This, in conjunction with the weakened cross-equatorial flow due to suppressed convective anomalies over the equatorial Indian Ocean reduce the tropospheric moisture over the Arabian Sea, and promote westerly wind anomalies that do not recurve over India. As a result the low-level cyclonic vorticity shifts from India to southeast Asia and break conditions are initiated over India, and (3) the circulation anomalies forced by equatorial Indian Ocean convective anomalies significantly influence the active/break phases over the tropical west Pacific. Our model solutions support

  2. A practical cooling strategy for reducing the physiological strain associated with firefighting activity in the heat.

    Science.gov (United States)

    Barr, D; Gregson, W; Sutton, L; Reilly, T

    2009-04-01

    The aim of this study was to establish whether a practical cooling strategy reduces the physiological strain during simulated firefighting activity in the heat. On two separate occasions under high ambient temperatures (49.6 +/- 1.8 degrees C, relative humidity (RH) 13 +/- 2%), nine male firefighters wearing protective clothing completed two 20-min bouts of treadmill walking (5 km/h, 7.5% gradient) separated by a 15-min recovery period, during which firefighters were either cooled (cool) via application of an ice vest and hand and forearm water immersion ( approximately 19 degrees C) or remained seated without cooling (control). There was no significant difference between trials in any of the dependent variables during the first bout of exercise. Core body temperature (37.72 +/- 0.34 vs. 38.21 +/- 0.17 degrees C), heart rate (HR) (81 +/- 9 vs. 96 +/- 17 beats/min) and mean skin temperature (31.22 +/- 1.04 degrees C vs. 33.31 +/- 1 degrees C) were significantly lower following the recovery period in cool compared with control (p second bout of activity in cool compared to control. Mean skin temperature, HR and thermal sensation were significantly lower during bout 2 in cool compared with control (p < 0.05). It is concluded that this practical cooling strategy is effective at reducing the physiological strain associated with demanding firefighting activity under high ambient temperatures. PMID:19401892

  3. The effects of Sao Paulo urban heat island on lightning activity: Decadal analysis (1999-2009)

    Science.gov (United States)

    Bourscheidt, Vandoir; Pinto, Osmar; Naccarato, Kleber P.

    2016-05-01

    Eleven years of lightning data from the Brazilian Integrated National Lightning Detection Network were used to analyze the effects of the urban heat island (UHI) of Sao Paulo on lightning activity, extending the investigation of previous works. Cloud-to-ground lightning data were analyzed in both spatial and temporal perspectives, using different approaches: flash density, flash rate, thunderstorm hours (TH), and the cell initiation technique (CIT), which aims to identify the onset of thunderstorms. Land surface temperature (LST) from MODIS (Moderate Resolution Imaging Spectroradiometer) was used to analyze the UHI evolution over the years. MODIS data were validated using ground stations, distributed within the urban area. Different time intervals (seasonal and intraday) were used in an attempt to separate local convective systems from synoptic-scale events. The results indicate significant effects of the UHI (using LST) on THs and CIT. The CIT showed a nearly ring pattern, especially during the afternoon (14:00-18:00 LT) of summer months, reinforcing temperature contrast as a condition for storm initiation. The results also suggest an amplification of the UHI effects on thunderstorm activity by local factors (sea and country breeze, synoptic events, and terrain). Higher flash rates were also observed throughout the urban region, which influences the lightning density. Temporal analysis indicates that minimum temperature and lightning activity increase in wintertime. In summary, the results agree with previous studies about the UHI and indicate its importance on lightning occurrence, especially by increasing the temperature contrast and the instability in these regions.

  4. Heat shock protein 60 activates B cells via the TLR4-MyD88 pathway.

    Science.gov (United States)

    Cohen-Sfady, Michal; Nussbaum, Gabriel; Pevsner-Fischer, Meirav; Mor, Felix; Carmi, Pnina; Zanin-Zhorov, Alexandra; Lider, Ofer; Cohen, Irun R

    2005-09-15

    We recently reported that soluble 60-kDa heat shock protein (HSP60) can directly activate T cells via TLR2 signaling to enhance their Th2 response. In this study we investigated whether HSP60 might also activate B cells by an innate signaling pathway. We found that human HSP60 (but not the Escherichia coli GroEL or the Mycobacterial HSP65 molecules) induced naive mouse B cells to proliferate and to secrete IL-10 and IL-6. In addition, the HSP60-treated B cells up-regulated their expression of MHC class II and accessory molecules CD69, CD40, and B7-2. We tested the functional ability of HSP60-treated B cells to activate an allogeneic T cell response and found enhanced secretion of both IL-10 and IFN-gamma by the responding T cells. The effects of HSP60 were found to be largely dependent on TLR4 and MyD88 signaling; B cells from TLR4-mutant mice or from MyD88 knockout mice showed decreased responses to HSP60. Care was taken to rule out contamination of the HSP60 with LPS as a causative factor. These findings add B cells to the complex web of interactions by which HSP60 can regulate immune responses. PMID:16148103

  5. Weak decays. [Lectures, phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Wojcicki, S.

    1978-11-01

    Lectures are given on weak decays from a phenomenological point of view, emphasizing new results and ideas and the relation of recent results to the new standard theoretical model. The general framework within which the weak decay is viewed and relevant fundamental questions, weak decays of noncharmed hadrons, decays of muons and the tau, and the decays of charmed particles are covered. Limitation is made to the discussion of those topics that either have received recent experimental attention or are relevant to the new physics. (JFP) 178 references

  6. decays to baryons

    Indian Academy of Sciences (India)

    Torsten Leddig

    2012-11-01

    From inclusive measurements, it is known that about 7% of all mesons decay into final states with baryons. In these decays, some striking features become visible compared to mesonic decays. The largest branching fractions come with quite moderate multiplicities of 3–4 hadrons. We note that two-body decays to baryons are suppressed relative to three- and four-body decays. In most of these analyses, the invariant baryon–antibaryon mass shows an enhancement near the threshold. We propose a phenomenological interpretation of this quite common feature of hadronization to baryons.

  7. Decay property of Timoshenko system in thermoelasticity

    KAUST Repository

    Said-Houari, Belkacem

    2011-12-30

    We investigate the decay property of a Timoshenko system of thermoelasticity in the whole space for both Fourier and Cattaneo laws of heat conduction. We point out that although the paradox of infinite propagation speed inherent in the Fourier law is removed by changing to the Cattaneo law, the latter always leads to a solution with the decay property of the regularity-loss type. The main tool used to prove our results is the energy method in the Fourier space together with some integral estimates. We derive L 2 decay estimates of solutions and observe that for the Fourier law the decay structure of solutions is of the regularity-loss type if the wave speeds of the first and the second equations in the system are different. For the Cattaneo law, decay property of the regularity-loss type occurs no matter what the wave speeds are. In addition, by restricting the initial data to U 0∈H s(R)∩L 1,γ(R) with a suitably large s and γ ∈ [0,1], we can derive faster decay estimates with the decay rate improvement by a factor of t -γ/2. © 2011 John Wiley & Sons, Ltd.

  8. Surface Cleaning or Activation?Control of Surface Condition Prior to Thermo-Chemical Heat Treatment

    Institute of Scientific and Technical Information of China (English)

    Brigitte Haase; Juan Dong; Jens Heinlein

    2004-01-01

    Actual heat treatment processes must face increasing specifications with reference to process quality, safety and results in terms of reproducibility and repeatability. They can be met only if the parts' surface condition is controlled during manufacturing and, especially, prior to the treatment. An electrochemical method for the detection of a steel part's surface condition is presented, together with results, consequences, and mechanisms concerning surface pre-treatment before the thermochemical process. A steel surface's activity or passivity can be detected electrochemically, independently from the chemical background. The selected method was the recording of potential vs. time curves at small constant currents, using a miniaturized electrochemical cell, a (nearly) non-destructive electrolyte and a potentio-galvanostatic setup. The method enables to distinguish types of surface contamination which do not interfere with the thermochemical process, from passive layers which do and must be removed. Whereas some types of passive layers can be removed using conventional cleaning processes and agents, others are so stable that their effects can only be overcome by applying an additional activation pre-treatment, e.g. oxynitriding.

  9. Decadal variation of ocean heat content and tropical cyclone activity over the Bay of Bengal

    Indian Academy of Sciences (India)

    Sankar Nath; S D Kotal; P K Kundu

    2016-02-01

    The upper ocean heat content up to 700 m depth (OHC700) is an important climatic parameter required for atmospheric and oceanographic studies like a cyclone. In this study, therefore, an attempt has been made to examine the inter-decadal variations of tropical cyclone (TC) activity and OHC700 over the Bay of Bengal (BOB) for the post-monsoon season (October–December) during 1955–2013 periods. The sea-surface temperature (SST), geopotential height at 500 hPa, low-level vorticity at 850 hPa, vertical wind shear between 200 and 850 hPa, middle tropospheric humidity at 500 hPa and outgoing long-wave radiation are also being studied using seasonal mean data. The results show a significant inter-decadal variation during 1955–2013, with two distinct decadal periods: active decadal period (ADP) (1955–1988) and inactive decadal period (IDP) (1989–2013). The anomalies of these parameters are opposite in phase for two periods. It is found that the large scale atmospheric features and oceanic parameters have significant inter-decadal variability, but frequency of the tropical cyclone is attributed to the variation in the atmospheric dynamic and thermodynamic conditions rather than the variation of oceanic parameters OHC700 and SSTs during the post-monsoon season.

  10. Detection of seal contamination in heat-sealed food packaging based on active infrared thermography

    Science.gov (United States)

    D'huys, Karlien; Saeys, Wouter; De Ketelaere, Bart

    2015-05-01

    In the food industry packaging is often applied to protect the product from the environment, assuring quality and safety throughout shelf life if properly performed. Packaging quality depends on the material used and the closure (seal). The material is selected based on the specific needs of the food product to be wrapped. However, proper closure of the package is often harder to achieve. One problem possibly jeopardizing seal quality is the presence of food particles between the seal. Seal contamination can cause a decreased seal strength and thus an increased packaging failure risk. It can also trigger the formation of microchannels through which air and microorganisms can enter and spoil the enclosed food. Therefore, early detection and removal of seal-contaminated packages from the production chain is essential. In this work, a pulsed-type active thermography method using the heat of the sealing bars as an excitation source was studied for detecting seal contamination. The cooling profile of contaminated seals was recorded. The detection performance of four processing methods (based on a single frame, a fit of the cooling profile, pulsed phase thermography and a matched filter) was compared. High resolution digital images served as a reference to quantify contamination. The lowest detection limit (equivalent diameter of 0.63 mm) and the lowest processing time (0.42 s per sample) were obtained for the method based on a single frame. Presumably, practical limitations in the recording stage prevented the added value of active thermography to be fully reflected in this application.

  11. Impact of individual acid flue gas components on mercury capture by heat-treated activated carbon

    Institute of Scientific and Technical Information of China (English)

    Jian-ming ZHENG; Jin-song ZHOU; Zhong-yang LUO; Ke-fa CEN

    2012-01-01

    Elemental mercury capture on heat-treated activated carbon (TAC) was studied using a laboratory-scale fixed bed reactor.The capability of TAC to perform Hg0 capture under both N2 and baseline gas atmospheres was studied and the effects of common acid gas constituents were evaluated individually to avoid complications resulting from the coexistence of multiple components.The results suggest that surface functional groups (SFGs) on activated carbon (AC) are vital to Hg0 capture in the absence of acid gases.Meanwhile,the presence of acid gas components coupled with defective graphitic lattices on TAC plays an important role in effective Hg0 capture.The presence of HCl,NO2,and NO individually in basic gases markedly enhances Hg0 capture on TAC due to the heterogeneous oxidation of Hg0 on acidic sites created on the carbon surface and catalysis by the defective graphitic lattices on TAC.Similarly,the presence of SO2 improves Hg0 capture by about 20%.This improvement likely results from the deposition of sulfur groups on the AC surface and oxidation of the elemental mercury by SO2 due to catalysis on the carbon surface.Furthermore,O2 exhibits a synergistic effect on Hg0 oxidation and capture when acid gases are present in the flue gases.

  12. Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores. I. Single Nanoflares

    Science.gov (United States)

    Barnes, W. T.; Cargill, P. J.; Bradshaw, S. J.

    2016-09-01

    The properties that are expected of “hot” non-flaring plasmas due to nanoflare heating in active regions are investigated using hydrodynamic modeling tools, including a two-fluid development of the Enthalpy Based Thermal Evolution of Loops code. Here we study a single nanoflare and show that while simple models predict an emission measure distribution extending well above 10 MK, which is consistent with cooling by thermal conduction, many other effects are likely to limit the existence and detectability of such plasmas. These include: differential heating between electrons and ions, ionization non-equilibrium, and for short nanoflares, the time taken for the coronal density to increase. The most useful temperature range to look for this plasma, often called the “smoking gun” of nanoflare heating, lies between 106.6 and 107 K. Signatures of the actual heating may be detectable in some instances.

  13. Dynamic Heat Storage and Cooling Capacity of a Concrete Deck with PCM and Thermally Activated Building System

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

    2012-01-01

    the performance of the new deck with PCM concrete is the thermal properties of such a new material, as the PCM concrete is yet to be well defined. The results presented in the paper include models in which the PCM concrete material properties, such as thermal conductivity, and specific heat capacity were first......This paper presents a heat storage and cooling concept that utilizes a phase change material (PCM) and a thermally activated building system (TABS) implemented in a hollow core concrete deck. Numerical calculations of the dynamic heat storage capacity of the hollow core concrete deck element...... with and without microencapsulated PCM are presented. The new concrete deck with microencapsulated PCM is the standard deck on which an additional layer of the PCM concrete was added and, at the same time, the latent heat storage was introduced to the construction. The challenge of numerically simulating...

  14. Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores I. Single Nanoflares

    CERN Document Server

    Barnes, W T; Bradshaw, S J

    2016-01-01

    The properties expected of "hot" non-flaring plasmas due to nanoflare heating in active regions are investigated using hydrodynamic modeling tools, including a two-fluid development of the EBTEL code. Here we study a single nanoflare and show that while simple models predict an emission measure distribution extending well above 10 MK that is consistent with cooling by thermal conduction, many other effects are likely to limit the existence and detectability of such plasmas. These include: differential heating between electrons and ions, ionization non-equilibrium and, for short nanoflares, the time taken for the coronal density to increase. The most useful temperature range to look for this plasma, often called the "smoking gun" of nanoflare heating, lies between $10^{6.6}$ and $10^7$ K. Signatures of the actual heating may be detectable in some instances.

  15. Apparent activation energy for densification of -Al2O3 powder at constant heating-rate sintering

    Indian Academy of Sciences (India)

    W Q Shao; S O Chen; D Li; H S Cao; Y C Zhang; S S Zhang

    2008-11-01

    The apparent activation energy for densification is a characteristic quantity that elucidates the fundamental diffusion mechanisms during the sintering process. Based on the Arrhenius theory, the activation energy for densification of -Al2O3 at constant heating-rates sintering has been estimated. Sintering of -Al2O3 powder has been executed by the way of a push rod type dilatometer. It is shown that the apparent activation energy does not have a single value but depends directly on the relative density. The apparent activation energy corresponding to lower relative density was higher than that corresponding to higher relative density. In addition, the value of the evaluated activation energy is different at the same density level when the Arrhenius plot involves different heating rates.

  16. Heat Treatment of Small Heat Shock Proteins α-Crystallin and Hsp16.3: Structural Changes vs. Chaperone-like Activity

    Institute of Scientific and Technical Information of China (English)

    毛启龙; 柯丹霞; 昌增益

    2001-01-01

    Both α-crystallin from bovine eye lens and Hsp16.3 from Mycobacterium tuberculosis are members of the small heat shock protein family, They were preincubated at 100 C for 15 min and then cooled on ice immediately. The chaperone-like activities of preheated proteins were measured at 37 C using DTT-treated insulin B chains as substrates. Both preheated proteins exhibited greatly enhanced chaperone-like activities, accompanied with almost unchanged secondary structures and surface hydrophobicity but with a minor change in tertiary structures. The dramatically enhanced chaperone-like activities of preheated α-crystallln and Hsp16.3 may have resulted from the irreversible change in the tertiary structure as detected by near-UV CD spectra.

  17. Diagnosing the time-dependence of active region core heating from the emission measure: II. Nanoflare trains

    CERN Document Server

    Reep, Jeffrey W; Klimchuk, James A; 10.1088/0004-637X/764/2/193

    2013-01-01

    The time-dependence of heating in solar active regions can be studied by analyzing the slope of the emission measure distribution cool-ward of the peak. In a previous study we showed that low-frequency heating can account for 0% to 77% of active region core emission measures. We now turn our attention to heating by a finite succession of impulsive events for which the timescale between events on a single magnetic strand is shorter than the cooling timescale. We refer to this scenario as a "nanoflare train" and explore a parameter space of heating and coronal loop properties with a hydrodynamic model. Our conclusions are: (1) nanoflare trains are consistent with 86% to 100% of observed active region cores when uncertainties in the atomic data are properly accounted for; (2) steeper slopes are found for larger values of the ratio of the train duration $\\Delta_H$ to the post-train cooling and draining timescale $\\Delta_C$, where $\\Delta_H$ depends on the number of heating events, the event duration and the time ...

  18. Oral vaccination with heat inactivated Mycobacterium bovis activates the complement system to protect against tuberculosis.

    Directory of Open Access Journals (Sweden)

    Beatriz Beltrán-Beck

    Full Text Available Tuberculosis (TB remains a pandemic affecting billions of people worldwide, thus stressing the need for new vaccines. Defining the correlates of vaccine protection is essential to achieve this goal. In this study, we used the wild boar model for mycobacterial infection and TB to characterize the protective mechanisms elicited by a new heat inactivated Mycobacterium bovis vaccine (IV. Oral vaccination with the IV resulted in significantly lower culture and lesion scores, particularly in the thorax, suggesting that the IV might provide a novel vaccine for TB control with special impact on the prevention of pulmonary disease, which is one of the limitations of current vaccines. Oral vaccination with the IV induced an adaptive antibody response and activation of the innate immune response including the complement component C3 and inflammasome. Mycobacterial DNA/RNA was not involved in inflammasome activation but increased C3 production by a still unknown mechanism. The results also suggested a protective mechanism mediated by the activation of IFN-γ producing CD8+ T cells by MHC I antigen presenting dendritic cells (DCs in response to vaccination with the IV, without a clear role for Th1 CD4+ T cells. These results support a role for DCs in triggering the immune response to the IV through a mechanism similar to the phagocyte response to PAMPs with a central role for C3 in protection against mycobacterial infection. Higher C3 levels may allow increased opsonophagocytosis and effective bacterial clearance, while interfering with CR3-mediated opsonic and nonopsonic phagocytosis of mycobacteria, a process that could be enhanced by specific antibodies against mycobacterial proteins induced by vaccination with the IV. These results suggest that the IV acts through novel mechanisms to protect against TB in wild boar.

  19. The influence of electric ARC activation on the speed of heating and the structure of metal in welds

    Directory of Open Access Journals (Sweden)

    Savytsky Oleksandr M.

    2016-01-01

    Full Text Available This paper presents the results of a research related to the impact of electric arc activation onto drive welding energy and metal weld heating speed. It is confirmed that ATIG and AMIG methods, depending on metal thickness, single pass weldability and chemical composition of activating flux, enable the reduction of welding energy by 2-6 times when compared to conventional welding methods. Additionally, these procedures create conditions to increase metal weld heating speed up to 1,500-5,500°C/s-1. Steel which can be rapidly heated, allows for a hardened structure to form (with carbon content up to 0.4%, together with a released martensitic structure or a mixture of bainitic-martensitic structures. Results of the research of effectiveness of ATIG and AMIG welding showed that increase in the penetration capability of electric arc, which increases welding productivity, is the visible side of ATIG and AMIG welding capabilities.

  20. Rare Decays at LHCb

    Science.gov (United States)

    Hall, Sam

    2014-04-01

    Rare decays of beauty and charm hadrons provide an effective method of testing the Standard Model and probing possible new physics scenarios. The LHCb experiment has published a variety of interesting results in this field, some of which are presented here. In particular the measurements of the branching fractions of B(s)0 → μ+μ- which, in combination with CMS, resulted in the first observation of the Bs0 → μ+μ- decay. Other topics include searches for the rare decay D0 → μ+μ-, the lepton flavour violating decays B(s)0 → e±μ∓, and the observation of the ψ(4160) resonance in the region of low recoil in B+ → K+μ+μ- decay. New results on the angular analysis of the decay B0 → K*0μ+μ- with form factor independent observables are also shown.

  1. Decay of 120Ba

    International Nuclear Information System (INIS)

    The decay of 120Ba has been studied with an on-line isotope separator. Its half-life was determined to be t1/2=24±2 s. A decay scheme is proposed, based on γ-γ, γ-X, and γ-β+ coincidence measurements, which takes account of all 16 observed γ rays. The total decay energy was measured to be QEC=50±0.3 MeV

  2. Effective Majorana neutrino decay

    CERN Document Server

    Duarte, Lucía; Peressutti, Javier; Sampayo, Oscar A

    2016-01-01

    We study the decay of heavy sterile Majorana neutrinos according to the interactions obtained from an effective general theory. We describe the two and three-body decays for a wide range of neutrino masses. The results obtained and presented in this work could be useful for the study of the production and detection of this particles in a variety of high energy physics experiments and astrophysical observations. We show in different figures the dominant branching ratios and the total decay width.

  3. RhoA Activation Sensitizes Cells to Proteotoxic Stimuli by Abrogating the HSF1-Dependent Heat Shock Response

    NARCIS (Netherlands)

    Meijering, Roelien A. M.; Wiersma, Marit; van Marion, Denise M. S.; Zhang, Deli; Hoogstra-Berends, Femke; Dijkhuis, Anne-Jan; Schmidt, Martina; Wieland, Thomas; Kampinga, Harm H.; Henning, Robert H.; Brundel, Bianca J. J. M.

    2015-01-01

    Background The heat shock response (HSR) is an ancient and highly conserved program of stress-induced gene expression, aimed at reestablishing protein homeostasis to preserve cellular fitness. Cells that fail to activate or maintain this protective response are hypersensitive to proteotoxic stress.

  4. Preparation and analysis of active rat model of rheumatoid arthritis with features of TCM toxic heat-stasis painful obstruction

    Directory of Open Access Journals (Sweden)

    Yanan Wang

    2015-07-01

    Conclusion: The CIA model established in this study presents both active RA pathologic features and characteristics of the symptoms of toxic heat-stasis painful obstruction 12 weeks after successful establishment of an animal model. In addition, this study may be a valuable reference for development of animal studies with combined Eastern and Western medicines in dialectics and identification of diseases.

  5. Structural features of Escherichia coli heat-stable enterotoxin that activates membrane-associated guanylyl cyclase.

    Science.gov (United States)

    Sato, T; Shimonishi, Y

    2004-03-01

    Heat-stable enterotoxin (ST), a small peptide of 18 or 19 amino acid residues produced by enterotoxigenic Escherichia coli, is the cause of acute diarrhea in infants and travelers in developing countries. ST triggers a biological response by binding to a membrane-associated guanylyl cyclase C (GC-C) which is located on intestinal epithelial cell membranes. This binding causes an increase in the concentration of cGMP as a second messenger in cells and activates protein kinase A and cystic fibrosis transmembrane conductance regulator. Here we describe the crystal structure of an ST at 0.89 A resolution. The molecule has a ring-shaped molecular architecture consisting of six peptide molecules with external and internal diameters of approximately 35 and 7 A, respectively and a thickness of approximately 11 A. The conserved residues at the central portion of ST are distributed on the outer surface of the ring-shaped peptide hexamer, suggesting that the hexamer may be implicated in the association with GC-C through these invariant residues. PMID:15049831

  6. Distinct Skeletal Muscle Gene Regulation from Active Contraction, Passive Vibration, and Whole Body Heat Stress in Humans

    Science.gov (United States)

    Petrie, Michael A.; Kimball, Amy L.; McHenry, Colleen L.; Suneja, Manish; Yen, Chu-Ling; Sharma, Arpit; Shields, Richard K.

    2016-01-01

    Skeletal muscle exercise regulates several important metabolic genes in humans. We know little about the effects of environmental stress (heat) and mechanical stress (vibration) on skeletal muscle. Passive mechanical stress or systemic heat stress are often used in combination with many active exercise programs. We designed a method to deliver a vibration stress and systemic heat stress to compare the effects with active skeletal muscle contraction. Purpose: The purpose of this study is to examine whether active mechanical stress (muscle contraction), passive mechanical stress (vibration), or systemic whole body heat stress regulates key gene signatures associated with muscle metabolism, hypertrophy/atrophy, and inflammation/repair. Methods: Eleven subjects, six able-bodied and five with chronic spinal cord injury (SCI) participated in the study. The six able-bodied subjects sat in a heat stress chamber for 30 minutes. Five subjects with SCI received a single dose of limb-segment vibration or a dose of repetitive electrically induced muscle contractions. Three hours after the completion of each stress, we performed a muscle biopsy (vastus lateralis or soleus) to analyze mRNA gene expression. Results: We discovered repetitive active muscle contractions up regulated metabolic transcription factors NR4A3 (12.45 fold), PGC-1α (5.46 fold), and ABRA (5.98 fold); and repressed MSTN (0.56 fold). Heat stress repressed PGC-1α (0.74 fold change; p < 0.05); while vibration induced FOXK2 (2.36 fold change; p < 0.05). Vibration similarly caused a down regulation of MSTN (0.74 fold change; p < 0.05), but to a lesser extent than active muscle contraction. Vibration induced FOXK2 (p < 0.05) while heat stress repressed PGC-1α (0.74 fold) and ANKRD1 genes (0.51 fold; p < 0.05). Conclusion: These findings support a distinct gene regulation in response to heat stress, vibration, and muscle contractions. Understanding these responses may assist in developing regenerative

  7. Monitoring cow activity and rumination time for an early detection of heat stress in dairy cow

    Science.gov (United States)

    Abeni, Fabio; Galli, Andrea

    2016-08-01

    The aim of this study was to explore the use of cow activity and rumination time by precision livestock farming tools as early alert for heat stress (HS) detection. A total of 58 Italian Friesian cows were involved in this study during summer 2015. Based on the temperature humidity index (THI), two different conditions were compared on 16 primiparous and 11 multiparous, to be representative of three lactation phases: early (15-84 DIM), around peak (85-154 DIM), and plateau (155-224 DIM). A separate dataset for the assessment of the variance partition included all the cows in the herd from June 7 to July 16. The rumination time (RT2h, min/2 h) and activity index (AI2h, bouts/2 h) were summarized every 2-h interval. The raw data were used to calculate the following variables: total daily RT (RTt), daytime RT (RTd), nighttime RT (RTn), total daily AI (AIt), daytime AI (AId), and nighttime AI (AIn). Either AIt and AId increased, whereas RTt, RTd, and RTn decreased with higher THI in all the three phases. The highest decrease was recorded for RTd and ranged from 49 % (early) to 45 % (plateau). The contribution of the cow within lactation phase was above 60 % of the total variance for AI traits and a share from 33.9 % (for RTt) to 54.8 % (RTn) for RT traits. These observations must be extended to different feeding managements and different animal genetics to assess if different thresholds could be identified to set an early alert system for the farmer.

  8. Relativistic evaluation of the two-photon decay of the metastable ${1s}^{2} 2s 2p~^3\\mbox{P}_0$ state in berylliumlike ions with an active-electron model

    CERN Document Server

    Amaro, Pedro; Safari, Laleh; Machado, Jorge; Guerra, Mauro; Indelicato, Paul; Santos, José Paulo

    2015-01-01

    The two-photon ${1s}^{2} 2s 2p~^3\\mbox{P}_0 \\rightarrow {1s}^{2} {2s}^2$ $^1\\mbox{S}_0$ transition in berylliumlike ions is theoretically investigated within a full relativistic framework and a second-order perturbation theory. We focus our analysis on how electron correlation, as well as the negative-energy spectrum can affect the forbidden $E1M1$ decay rate. For this purpose we include the electronic correlation by an effective potential and within an active-electron model. Due to its experimental interest, evaluation of decay rates are performed for berylliumlike xenon and uranium. We find that the negative-energy contribution can be neglected in the present decay rate. On the other hand, if contributions of electronic correlation are not carefully taken into account, it may change the lifetime of the metastable state by 20\\%. By performing a full-relativistic $jj$-coupling calculation, we found discrepancies for the decay rate of an order of 2 compared to non-relativistic $LS$-coupling calculations, for t...

  9. Enzyme Activity Dynamics in Response to Climate Change: 2011 Drought-Heat Wave

    Science.gov (United States)

    Extreme weather events such as severe droughts and heat waves may have permanent consequences on soil quality and functioning in agroecosystems. The Southern High Plains (SHP) region of Texas, U.S., a large cotton producing area, experienced a historically extreme drought and heat wave during 2011,...

  10. Thermo Active Building Systems Using Building Mass To Heat and Cool

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.

    2012-01-01

    Using the thermal storage capacity of the concrete slabs between each floor in multistory buildings to heat or cool is a trend that began in the early 1990s in Switzerland.1,2 Pipes carrying water for heating and cooling are embedded in the center of the concrete slab. In central Europe (Germany...

  11. Thermo Active Building Systems – Using Building Mass To Heat and Cool

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.

    2014-01-01

    Using the thermal storage capacity of the concrete slabs between each floor in multistory buildings to heat or cool is a trend that began in the early 1990s in Switzerland.1,2 Pipes carrying water for heating and cooling are embedded in the center of the concrete slab. In central Europe (Germany...

  12. RhoA Activation Sensitizes Cells to Proteotoxic Stimuli by Abrogating the HSF1-Dependent Heat Shock Response.

    Directory of Open Access Journals (Sweden)

    Roelien A M Meijering

    Full Text Available The heat shock response (HSR is an ancient and highly conserved program of stress-induced gene expression, aimed at reestablishing protein homeostasis to preserve cellular fitness. Cells that fail to activate or maintain this protective response are hypersensitive to proteotoxic stress. The HSR is mediated by the heat shock transcription factor 1 (HSF1, which binds to conserved heat shock elements (HSE in the promoter region of heat shock genes, resulting in the expression of heat shock proteins (HSP. Recently, we observed that hyperactivation of RhoA conditions cardiomyocytes for the cardiac arrhythmia atrial fibrillation. Also, the HSR is annihilated in atrial fibrillation, and induction of HSR mitigates sensitization of cells to this disease. Therefore, we hypothesized active RhoA to suppress the HSR resulting in sensitization of cells for proteotoxic stimuli.Stimulation of RhoA activity significantly suppressed the proteotoxic stress-induced HSR in HL-1 atrial cardiomyocytes as determined with a luciferase reporter construct driven by the HSF1 regulated human HSP70 (HSPA1A promoter and HSP protein expression by Western Blot analysis. Inversely, RhoA inhibition boosted the proteotoxic stress-induced HSR. While active RhoA did not preclude HSF1 nuclear accumulation, phosphorylation, acetylation, or sumoylation, it did impair binding of HSF1 to the hsp genes promoter element HSE. Impaired binding results in suppression of HSP expression and sensitized cells to proteotoxic stress.These results reveal that active RhoA negatively regulates the HSR via attenuation of the HSF1-HSE binding and thus may play a role in sensitizing cells to proteotoxic stimuli.

  13. Fluoridation and oxidation behavior of JLF-1 and NIFS-HEAT-2 low activation structural materials

    Energy Technology Data Exchange (ETDEWEB)

    Nagasaka, T.; Muroga, T. [National Institute for Fusion Science - NIFS, Toki, Gifu (Japan); Kondo, M. [Fusion Engineering Research Center, National Institute for Fusion Science, Toki, Gifu (Japan); Nishimura, H. [Tokyo Univ., Graduate School of Engineering, Nuclear Pressional School, Tokai, Naka, Ibaraki (Japan); Noda, N. [National Institute for Fusion Science, Gifu (Japan)

    2007-07-01

    Full text of publication follows: Corrosion of structural materials, such as JLF-1 (Fe-9Cr-2W-0.1C-V-Ta) and NIFSHEAT- 2 (V-4Cr-4Ti), is paid attention most in Flibe (LiF-BeF{sub 2}) blanket development. In a previous corrosion study on steels, only oxides were identified as corrosion products after a conventional Flibe exposure test, while fluorides were indicated in another report with high purity Flibe after dehydration treatment. In order to clarify the corrosion mechanism in Flibe, it is essential to understand the competitive process by fluoridation and oxidation. Purpose of the present study is to characterize corrosion products of the low activation materials after fluoridation, oxidation and Flibe exposure tests, and to evaluate corrosion resistance of the materials in various conditions. JLF-1 JOYO-II heat and NIFS-HEAT-2 were machined and polished into specimens with 1 x 10 x 20 mm or 1 x 10 x 15 mm in size. The same size specimens of pure Fe, Cr, W, V and Ti were also prepared. The specimens were exposed to HF-H{sub 2}O solution at room temperature, and to flowing He-HF-O{sub 2} gas mixture and static molten salt Flibe at 673-873 K. High purity HF gas was made by a reaction between NiF{sub 2} and dehydrated He-H{sub 2} gas mixture. Flibe was dehydrated by HF gas bubbling treatment. After the exposure tests, weight change was measured. Corrosion products and microstructural change at the surface were characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). In a XRD spectrum of JLF-1 after Flibe exposure at 823 K for 2003 hr, some peaks considered as FeF{sub 2} and CrF{sub 2} were observed, however their intensity was not enough to identify the compounds. The morphology and composition of the corrosion products were analyzed by SEM and compared with the one made in accelerated fluoridation tests with various composition of He-HF-O{sub 2} gas mixture. (authors)

  14. Fluoridation and oxidation behavior of JLF-1 and NIFS-HEAT-2 low activation structural materials

    International Nuclear Information System (INIS)

    Full text of publication follows: Corrosion of structural materials, such as JLF-1 (Fe-9Cr-2W-0.1C-V-Ta) and NIFSHEAT- 2 (V-4Cr-4Ti), is paid attention most in Flibe (LiF-BeF2) blanket development. In a previous corrosion study on steels, only oxides were identified as corrosion products after a conventional Flibe exposure test, while fluorides were indicated in another report with high purity Flibe after dehydration treatment. In order to clarify the corrosion mechanism in Flibe, it is essential to understand the competitive process by fluoridation and oxidation. Purpose of the present study is to characterize corrosion products of the low activation materials after fluoridation, oxidation and Flibe exposure tests, and to evaluate corrosion resistance of the materials in various conditions. JLF-1 JOYO-II heat and NIFS-HEAT-2 were machined and polished into specimens with 1 x 10 x 20 mm or 1 x 10 x 15 mm in size. The same size specimens of pure Fe, Cr, W, V and Ti were also prepared. The specimens were exposed to HF-H2O solution at room temperature, and to flowing He-HF-O2 gas mixture and static molten salt Flibe at 673-873 K. High purity HF gas was made by a reaction between NiF2 and dehydrated He-H2 gas mixture. Flibe was dehydrated by HF gas bubbling treatment. After the exposure tests, weight change was measured. Corrosion products and microstructural change at the surface were characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). In a XRD spectrum of JLF-1 after Flibe exposure at 823 K for 2003 hr, some peaks considered as FeF2 and CrF2 were observed, however their intensity was not enough to identify the compounds. The morphology and composition of the corrosion products were analyzed by SEM and compared with the one made in accelerated fluoridation tests with various composition of He-HF-O2 gas mixture. (authors)

  15. Study of plate-fin heat exchanger and cold plate for the active thermal control system of Space Station

    Science.gov (United States)

    Chyu, MING-C.

    1992-01-01

    Plate-fin heat exchangers will be employed in the Active Thermal Control System of Space Station Freedom. During ground testing of prototypic heat exchangers, certain anomalous behaviors have been observed. Diagnosis has been conducted to determine the cause of the observed behaviors, including a scrutiny of temperature, pressure, and flow rate test data, and verification calculations based on such data and more data collected during the ambient and thermal/vacuum tests participated by the author. The test data of a plate-fin cold plate have been also analyzed. Recommendation was made with regard to further tests providing more useful information of the cold plate performance.

  16. Elemental activation analysis with decay and prompt gamma ray techniques, using isotopic neutron sources and a nuclear research reactor. Part of a coordinated programme on nuclear-based techniques in geology and mineral prospecting

    International Nuclear Information System (INIS)

    This is to review the research activities carried out through the IAEA research Project 1697/RB ''Elemental activation analysis with decay and prompt gamma ray techniques, using isotopic neutron sources and the nuclear research reactor. The programme of work includes: a) Development of decay and prompt gamma ray activation techniques for mineral exploration. b) Development of epithermal NAA in addition to thermal NAA especially for gold ore. c) Development of non-destructive insitu elemental analysis with decay and prompt gamma ray techniques using isotopic neutron sources. A joint programme has been established with the Egyptian Geological Surrey and Mining Authority for using nuclear techniques in evaluating gold prospects of several ancient gold mines and investigating several tin-tantalum deposits, which were discovered over the last few years. Two sources of neutrons were used for irradiation, one of the dry channels of the two megawatts research reactor, ET-RR-1 for laboratory studies, and a Pu-Be neutron source in paraffin assembly for possible insitu work

  17. The passive and active nature of ocean heat uptake in idealized climate change experiments

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Peng; Vallis, Geoffrey K. [Princeton University, AOS Program, Princeton, NJ (United States)

    2012-02-15

    The influence of ocean circulation changes on heat uptake is explored using a simply-configured primitive equation ocean model resembling a very idealized Atlantic Ocean. We focus on the relative importance of the redistribution of the existing heat reservoir (due to changes in the circulation) and the contribution from anomalous surface heat flux, in experiments in which the surface boundary conditions are changed. We perform and analyze numerical experiments over a wide range of parameters, including experiments that simulate global warming and others that explore the robustness of our results to more general changes in surface boundary conditions. We find that over a wide range of values of diapycnal diffusivity and Southern Ocean winds, and with a variety of changes in surface boundary conditions, the spatial patterns of ocean temperature anomaly are nearly always determined as much or more by the existing heat reservoir redistribution than by the nearly passive uptake of temperature due to changes in the surface boundary conditions. Calculating heat uptake by neglecting the existing reservoir redistribution, which is similar to treating temperature as a passive tracer, leads to significant quantitative errors notably at high-latitudes and, secondarily, in parts of the main thermocline. Experiments with larger circulation changes tend to produce a relatively larger magnitude of existing reservoir redistribution, and a faster growing effective heat capacity of the system. The effective heat capacity is found to be sensitive to both vertical diffusivity and Southern Ocean wind. (orig.)

  18. Dark Radiation and Decaying Matter

    OpenAIRE

    Gonzalez-Garcia, M. C.; Niro, V.; Salvado, Jordi

    2012-01-01

    Recent cosmological measurements favour additional relativistic energy density beyond the one provided by the three active neutrinos and photons of the Standard Model (SM). This is often referred to as "dark radiation", suggesting the need of new light states in the theory beyond those of the SM. In this paper, we study and numerically explore the alternative possibility that this increase comes from the decay of some new form of heavy matter into the SM neutrinos. We study the constraints on...

  19. Rare Semileptonic Charm Decays

    CERN Document Server

    de Boer, Stefan

    2015-01-01

    An analysis of charm mesons decaying semileptonically via Flavor Changing Neutral Currents is presented. We calculate the Wilson coefficients within the Standard Model. A window in the decay distribution, where physics beyond the Standard Model could be measured is identified. Exemplary, we study effects of leptoquark models.

  20. Decay of hypernuclei

    International Nuclear Information System (INIS)

    The pionic and non-mesonic decays of hypernuclei are discussed. In the first part, various decay processes which could be useful to obtain information of hypernuclear structure are discussed. The experimental data concerning the pionic and non-mesonic decays are discussed in the second part. As the experimental data, there are only few lifetime data and some crude data on the non-mesonic to π decay ratio. In the third and the fourth parts, some theoretical analyses are made on the pionic and the nonmesonic decays. DDHF calculation was performed for Λ and N systems by using Skyrme type ΛN and NN effective interactions. A suppression factor of the order of 10-3 for A nearly equal 100 was obtained. (Aoki, K.)

  1. Enhancing methane production from waste activated sludge using combined free nitrous acid and heat pre-treatment.

    Science.gov (United States)

    Wang, Qilin; Jiang, Guangming; Ye, Liu; Yuan, Zhiguo

    2014-10-15

    Methane production from anaerobic digestion of waste activated sludge (WAS) is often limited by the slow degradation and poor substrate availability of WAS. Our previous study revealed that WAS pre-treatment using free nitrous acid (FNA, i.e. HNO2) is an economically feasible and environmentally friendly method for promoting methane production. In order to further improve methane production from WAS, this study presents a novel strategy based on combined FNA and heat pre-treatment. WAS from a full-scale plant was treated for 24 h with FNA alone (0.52-1.43 mg N/L at 25 °C), heat alone (35, 55 and 70 °C), and FNA (0.52-1.11 mg N/L) combined with heat (35, 55 and 70 °C). The pre-treated WAS was then used for biochemical methane potential tests. Compared to the control (no FNA or heat pre-treatment of WAS), biochemical methane potential of the pre-treated WAS was increased by 12-16%, 0-6%, 17-26%, respectively; hydrolysis rate was improved by 15-25%, 10-25%, 20-25%, respectively, for the three types of pre-treatment. Heat pre-treatment at 55 and 70 °C, independent of the presence or absence of FNA, achieved approximately 4.5 log inactivation of pathogens (in comparison to ∼1 log inactivation with FNA treatment alone), thus capable of producing Class A biosolids. The combined FNA and heat pre-treatment is an economically and environmentally attractive technology for the pre-treatment of WAS prior to anaerobic digestion, particularly considering that both FNA and heat can be produced as by-products of anaerobic sludge digestion.

  2. Mesothelioma Cells Escape Heat Stress by Upregulating Hsp40/Hsp70 Expression via Mitogen-Activated Protein Kinases

    Directory of Open Access Journals (Sweden)

    Michael Roth

    2009-01-01

    Full Text Available Therapy with hyperthermal chemotherapy in pleural diffuse malignant mesothelioma had limited benefits for patients. Here we investigated the effect of heat stress on heat shock proteins (HSP, which rescue tumour cells from apoptosis. In human mesothelioma and mesothelial cells heat stress (39–42°C induced the phosphorylation of two mitogen activated kinases (MAPK Erk1/2 and p38, and increased Hsp40, and Hsp70 expression. Mesothelioma cells expressed more Hsp40 and were less sensitive to heat stress compared to mesothelial cells. Inhibition of Erk1/2 MAPK by PD98059 or by Erk1 siRNA down-regulated heat stress-induced Hsp40 and Hsp70 expression and reduced mesothelioma cell survival. Inhibition of p38MAPK by SB203580 or siRNA reduced Hsp40, but not Hsp70, expression and also increased mesothelioma cell death. Thus hyperthermia combined with suppression of p38 MAPK or Hsp40 may represent a novel approach to improve mesothelioma therapy.

  3. Heat stress activates phospholipase D and triggers PIP2 accumulation at the plasma membrane and nucleus

    NARCIS (Netherlands)

    M. Mishkind; J.E.M. Vermeer; E. Darwish; T. Munnik

    2009-01-01

    Heat stress induces an array of physiological adjustments that facilitate continued homeostasis and survival during periods of elevated temperatures. Here, we report that within minutes of a sudden temperature increase, plants deploy specific phospholipids to specific intracellular locations: phosph

  4. Age and heat exposure-dependent changes in antioxidant enzymes activities in rat's liver and brain mitochondria: role of alpha-tocopherol.

    Science.gov (United States)

    Stojkovski, V; Hadzi-Petrushev, N; Ilieski, V; Sopi, R; Gjorgoski, I; Mitrov, D; Jankulovski, N; Mladenov, M

    2013-01-01

    To investigate the role of mitochondrial antioxidant capacity during increased susceptibility to heat accompanied by the aging, young and aged Wistar rats were exposed on heat for 60 min. After heat exposure, hepatic and brain mitochondria were isolated. Our results revealed changes in antioxidant enzyme activities in liver and brain mitochondria from young and to a greater extent in aged rats. Our measurements of MnSOD, GPx and GR activity indicate greater reactive oxygen species production from the mitochondria of aged heat exposed in comparison to young heat exposed rats. Also in the aged rats, the effect of alpha-tocopherol treatment in the prevention of oxidative stress occurred as a result of heat exposure, is less pronounced. Taken together, our data suggest that mitochondria in aged rats are more vulnerable and less able to prevent oxidative changes that occur in response to acute heat exposure.

  5. Role of radiogenic heat generation in surface heat flow formation

    Science.gov (United States)

    Khutorskoi, M. D.; Polyak, B. G.

    2016-03-01

    Heat generation due to decay of long-lived radioactive isotopes is considered in the Earth's crust of the Archean-Proterozoic and Paleozoic provinces of Eurasia and North America. The heat flow that forms in the mantle is calculated as the difference between the heat flow observed at the boundary of the solid Earth and radiogenic heat flow produced in the crust. The heat regime in regions with anomalously high radiogenic heat generation is discussed. The relationship between various heat flow components in the Precambrian and Phanerozoic provinces has been comparatively analyzed, and the role of erosion of the surfaceheat- generating layer has been estimated.

  6. The response of electron transport mediated by active NADPH dehydrogenase complexes to heat stress in the cyanobacterium Synechocystis 6803

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The electron-transport machinery in photosynthetic membranes is known to be very sensitive to heat. In this study, the rate of electron transport (ETR) driven by photosystem I (PSI) and photosystem II (PSII) during heat stress in the wild-type Synechocystis sp. strain PCC 6803 (WT) and its ndh gene inactiva-tion mutants △ndhB (M55) and △ndhD1/ndhD2 (D1/D2) was simultaneously assessed by using the novel Dual-PAM-100 measuring system. The rate of electron transport driven by the photosystems (ETRPSs) in the WT, M55, and D1/D2 cells incubated at 30℃ and at 55℃ for 10 min was compared. Incubation at 55 ℃ for 10 min significantly inhibited PSII-driven ETR (ETRPSII) in the WT, M55 and D1/D2 cells, and the ex-tent of inhibition in both the M55 and D1/D2 cells was greater than that in the WT cells. Further, PSI-driven ETR (ETRPSI) was stimulated in both the WT and D1/D2 cells, and this rate was increased to a greater extent in the D1/D2 than in the WT cells. However, ETRPSI was considerably inhibited in the M55 cells. Analysis of the effect of heat stress on ETRPSs with regard to the alterations in the 2 active NDH-1 complexes in the WT, M55, and D1/D2 cells indicated that the active NDH-1 supercomplex and medi-umcomplex are essential for alleviating the heat-induced inhibition of ETRPSII and for accelerating the heat-induced stimulation of ETRPSI, respectively. Further, it is believed that these effects are most likely brought about by the electron transport mediated by each of these 2 active NDH-1 complexes.

  7. Applying the Active Heating Pulse DFOT Method to Drip Irrigation. Characterization of a wetting bulb in drip emitter

    Science.gov (United States)

    Benitez-Buelga, J.; Rodriguez-Sinobas, L.; María Gil-Rodríguez, M.; Sayde, C.; Selker, J. S.

    2011-12-01

    The use of Distributed Fiber Optic Temperature Measurement (DFOT) method for estimating temperature variation along a cable of fiber optic has been largely reported in multiple environmental applications. Recently , its usage has been combined with an active heating pulses technique- measurement of the temperature increase when a certain amount of tension is applied to the stainless jacket surrounding the fiber optic cable-in order to estimate soil water content in field and laboratory conditions with great accuracy . Thus, a methodology potentially capable of monitoring spatial variability and accurately estimates soil water content is created. This study presents a direct application of the Active Heated DFOT method for measuring soil water distribution and wetting bulb of a single drip emitter. In order to do so, three concentric helixes of fiber optics were placed in a hexagonal column of Plexiglas of 0.5 m base radius and 0.6 m height. After being filled up with air-dried loamy soil of controlled bulk density, a pressure compensating drip emitter of 2 L/h discharge was placed on top of the soil column. For an irrigation time of 5 hours and 40 min, 21 heating pulses of 2 minutes and 20W/m, were applied. In addition, soil samples after each heat pulse were also collected. Results showed the potential of this method for monitoring soil water behavior during irrigation and also its capability to estimate soil water content with accuracy.

  8. Effects of Heat, pH, and Gamma Irradiation Treatments on Lipase Inhibitory Activity of Sargassum thunbergii Ethanol Extract

    International Nuclear Information System (INIS)

    Inhibitory activity of Sagassum thunbergii (ST) against porcine pancreatic lipase was assessed after heat treatment, pH changes, and gamma irradiation. This analysis revealed that the ST ethanol extract exhibited high lipase inhibitory activity (37.37%) at 5 mg/mL. The ST ethanol extract was treated with heat at 60°C for 10, 30, and 60 min; 80 and 100°C for 10 and 20 min; and 121°C for 15 min, pH (2, 4, 6, 8 and 10) and γ -irradiation (3, 7 and 20 kGy). The lipase inhibitory activity of the ST ethanol extract increased in all heat treatments, especially at 121°C for 15 min (51.55%) compared with the control. With regard to pH stability, the ST ethanol extract showed no significant changes at pH 4 ~ 8, but somewhat decreased inhibitory activity was revealed at pH 2 (26.25%) and 10 (29.93%). On the other hand, the ST ethanol extract was not affected by γ -irradiation treatment conditions used in this study. These results suggest that ST has a potential role as a functional food agent. (author)

  9. Weak Decay of Hypernuclei

    CERN Document Server

    Alberico, W M

    2004-01-01

    The focus of these Lectures is on the weak decay modes of hypernuclei, with special attention to Lambda-hypernuclei. The subject involves many fields of modern theoretical and experimental physics, from nuclear structure to the fundamental constituents of matter and their interactions. The various weak decay modes of Lambda-hypernuclei are described: the mesonic mode and the non-mesonic ones. The latter are the dominant decay channels of medium--heavy hypernuclei, where, on the contrary, the mesonic decay is disfavoured by Pauli blocking effect on the outgoing nucleon. In particular, one can distinguish between one-body and two-body induced decays. Theoretical models employed to evaluate the (partial and total) decay widths of hypernuclei are illustrated, and their results compared with existing experimental data. Open problems and recent achievements are extensively discussed, in particular the determination of the ratio Gamma_n/Gamma_p, possible tests of the Delta I=1/2 rule in non-mesonic decays and the pu...

  10. Antibacterial activity of hen egg white lysozyme modified by heat and enzymatic treatments against oenological lactic acid bacteria and acetic acid bacteria.

    Science.gov (United States)

    Carrillo, W; García-Ruiz, A; Recio, I; Moreno-Arribas, M V

    2014-10-01

    The antimicrobial activity of heat-denatured and hydrolyzed hen egg white lysozyme against oenological lactic acid and acetic acid bacteria was investigated. The lysozyme was denatured by heating, and native and heat-denatured lysozymes were hydrolyzed by pepsin. The lytic activity against Micrococcus lysodeikticus of heat-denatured lysozyme decreased with the temperature of the heat treatment, whereas the hydrolyzed lysozyme had no enzymatic activity. Heat-denatured and hydrolyzed lysozyme preparations showed antimicrobial activity against acetic acid bacteria. Lysozyme heated at 90°C exerted potent activity against Acetobacter aceti CIAL-106 and Gluconobacter oxydans CIAL-107 with concentrations required to obtain 50% inhibition of growth (IC50) of 0.089 and 0.013 mg/ml, respectively. This preparation also demonstrated activity against Lactobacillus casei CIAL-52 and Oenococcus oeni CIAL-91 (IC50, 1.37 and 0.45 mg/ml, respectively). The two hydrolysates from native and heat-denatured lysozyme were active against O. oeni CIAL-96 (IC50, 2.77 and 0.3 mg/ml, respectively). The results obtained suggest that thermal and enzymatic treatments increase the antibacterial spectrum of hen egg white lysozyme in relation to oenological microorganisms.

  11. Comparison of the effects of millimeter wave irradiation, general bath heating, and localized heating on neuronal activity in the leech ganglion

    Science.gov (United States)

    Romanenko, Sergii; Siegel, Peter H.; Wagenaar, Daniel A.; Pikov, Victor

    2013-02-01

    The use of electrically-induced neuromodulation has grown in importance in the treatment of multiple neurological disorders such as Parkinson's disease, dystonia, epilepsy, chronic pain, cluster headaches and others. While electrical current can be applied locally, it requires placing stimulation electrodes in direct contact with the neural tissue. Our goal is to develop a method for localized application of electromagnetic energy to the brain without direct tissue contact. Toward this goal, we are experimenting with the wireless transmission of millimeter wave (MMW) energy in the 10-100 GHz frequency range, where penetration and focusing can be traded off to provide non-contact irradiation of the cerebral cortex. Initial experiments have been conducted on freshly-isolated leech ganglia to evaluate the real-time changes in the activity of individual neurons upon exposure to the MMW radiation. The initial results indicate that low-intensity MMWs can partially suppress the neuronal activity. This is in contrast to general bath heating, which had an excitatory effect on the neuronal activity. Further studies are underway to determine the changes in the state of the membrane channels that might be responsible for the observed neuromodulatory effects.

  12. Weak radiative hyperon decays

    International Nuclear Information System (INIS)

    New measurements of the Σ+ and Λ weak radiative decays are discussed. The hyperons were produced at rest by the reaction K-p → Yπ where Y = Σ+ or Λ. The monoenergetic pion was used to tag the hyperon production, and the branching ratios were determined from the relative amplitudes of Σ+ → pγ to Σ+ → pπ0 and Λ → nγ to Λ → nπ0. The photons from weak radiative decays and from π0 decays were detected with modular NaI arrays. (orig.)

  13. Axions from wall decay

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S; Hagmann, C; Sikivie, P

    2001-01-08

    The authors discuss the decay of axion walls bounded by strings and present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale of order the light travel time, and the average energy of the radiated axions is {approx_equal} 7m{sub a} for v{sub a}/m{sub a} {approx_equal} 500. is found to increase approximately linearly with ln(v{sub a}/m{sub a}). Extrapolation of this behavior yields {approx_equal} 60 m{sub a} in axion models of interest.

  14. Rare decays at LHCb

    CERN Document Server

    Lafferty, George

    2015-01-01

    We review recent results from the LHCb experiment on studies of particle decays that are forbidden or rare in the Standard Model. The studies include searches for lepton flavour violating decays of the $\\tau$ lepton and the $B$ and $D$ mesons, and of $B$ and $D$ meson decays that would be mediated by Majorana neutrinos. Results are also presented for the rare processes $B_s \\to \\mu^+\\mu^-$ and $B^0 \\to \\mu^+\\mu^-$, $D^0 \\to \\pi^+\\pi^-\\mu^+\\mu^-$, $b \\to s\\gamma$ transitions, and $B \\to K^{(*)}\\mu^+\\mu^-$.

  15. Diploid Gynogenesis Induced by Heat Shock after Activation with UV-Irradiated Sperm in Rainbow Trout (Oncorhynchus Mykiss

    Directory of Open Access Journals (Sweden)

    Ioan Bencsik

    2011-05-01

    Full Text Available Gynogenesis is a technique used to generate diploid individuals with genetic material exclusively of maternal origin. In this study we test the hypothesis that heat shock treatment of rainbow trout eggs, activated with UV irradiated sperms, leads to the generation of a uniform populations of diploid gynogenetic females. Activation of fertilized eggs with UV irradiated semen, by heat shock at 27.5°C for 10 min. directly after fertilization induces diploid gynogenesis. Diploid individuals are obtained at a rate of 73.33%. Triploid individuals are obtained at a rate of 26.67%. The enhanced number of triploid individuals may be due to insufficient irradiation of heritable material of sperm.

  16. A contribution to the investigation of the heat load of shock absorbers of semi-active suspensions in motor vehicles

    Directory of Open Access Journals (Sweden)

    Miroslav D. Demić

    2013-10-01

    Full Text Available Dynamic simulation, based on modeling, has a significant role during the process of vehicle development. It is especially important in the first stages of vehicle design, when relevant vehicle parameters are to be defined. Shock absorbers as executive parts of vehicle semi-active suspension systems suffer thermal loads, which may result in damage and degradation of ther characteristics. Therefore,this paper shows an attempt to analyze converting of mechanical work into heat by using the dynamic simulation method. Introduction Shock absorbers are integral elements of semi-active suspension systems for vehicles (hereinafter SASS. They directly affect the active vehicle safety. The role of shock absorbers is to absorb mechanical vibrations transferred from the road and to ensure the safety of passengers in a vehicle. The kinetic energy of vehicle vibrations transforms into mechanical work or heat in shock absorbers. In practice, in the first stage of vehicle development, the shock absorber parameters are chosen from the condition of damping vibrations of vehicles, but their thermal shock loads should be also taken into account. Motor vehicles have complex dynamic characteristics manifested by spatial movement, parameters change during operation, a number of disturbing influences, backlash, friction, hysteresis, etc. The above-mentioned dynamic phenomena, especially vibration, lead to fatigue of driver and users, reduce the life of the vehicle and its systems, etc. The main objective of the system is to reduce the reliance of the above-mentioned negative effects, improving the vehicle behavior on the road and allow the exploitation of vehicles in a wide range of service conditions. Classical systems cannot satisfiy these conditions, so there was a need to introduce new suspension systems with controlled characteristics (briefly called "semi-active", or "active" systems. Oscillatory model of vehicle The differential equations of vibratory motion of

  17. Study on Influence of Accelerated Heat-treatment on Weight Loss and Decay Resistance of Wood%浸渍药剂加速热处理对木材质量损失和耐腐性能的影响

    Institute of Scientific and Technical Information of China (English)

    陈利芳; 何雪香; 张燕君; 谢桂军; 王剑菁

    2012-01-01

    In this paper, three reagents including the main component of zinc chloride, ammonium di-hydrogen phosphate and the compound copper salt were impregnated into Pinus massoniana wood and Eucalyptus wood before heat-treatment, and then the weight loss and decay resistance of treated wood were studied. Results showed that as the temperature ascending and processing time expending, the weight loss 'and decay resistance of both the un-impregnated and impregnated wood increased, and zinc chloride had a significant impact on the weight loss at high temperature heat-treatment. It showed that this combined treatment has played a significant catalytic acceleration response role, however when the processing conditions were the same, the decay resistance performance of the wood pre-treated by zinc chloride and compound the copper salt were better than the un-impregnated one. The decay resistance level of treated wood in 190t which impregnated by the compound copper salt could reach level I ( strong decay resistance) .%采用主要成分为氯化锌、磷酸二氢铵及复合铜盐(硝酸铜+醋酸铜)的三种药剂对马尾松和桉树木材做浸渍处理后再进行短周期加热处理的方法,研究了处理工艺对热处理木材失重率和耐腐性能的影响.结果表明:处理木材的失重率和耐腐性能均随着处理温度升高和处理时间的延长而增大,氯化锌药剂热处理木材在较高温度下对木材的失重率影响最大,具有明显加速热处理反应的作用;但是在同样的热处理温度条件下,浸渍氯化锌和复合铜盐的热处理木材耐腐性明显优于未加药剂的热处理木材.三种药剂中,由复合铜盐浸渍处理的木材经190℃热处理后能达到强耐腐等级.

  18. Non-leptonic decays of beauty decays

    CERN Document Server

    Bigi, Ikaros I; Shifman, M; Uraltsev, N; Vainshtein, A I

    1994-01-01

    "Anyone who keeps the ability to see beauty never grows old" (Franz Kafka). In the last few years considerable progress has been achieved in our understanding of the decays of heavy flavour hadrons. One can now calculate inclusive transition rates in QCD proper through an expansion in inverse powers of the heavy flavour quark mass without recourse to phenomenological assumptions. The non-perturbative contributions are treated systematically in this way; they are found to produce corrections of order a few percent in beauty decays, i.e. typically somewhat smaller than the perturbative corrections. One finds, among other things: (a) The lifetime of $B^-$ mesons is predicted to be longer than that of $B^0$ mesons by several percent. (b) The QCD prediction for the semileptonic branching ratio of $B$ mesons appears to exceed present experimental values.

  19. Cloning of ubiquitin-activating enzyme and ubiquitin-conjugating enzyme genes from Gracilaria lemaneiformis and their activity under heat shock.

    Science.gov (United States)

    Li, Guang-Qi; Zang, Xiao-Nan; Zhang, Xue-Cheng; Lu, Ning; Ding, Yan; Gong, Le; Chen, Wen-Chao

    2014-03-15

    To study the response of Gracilaria lemaneiformis to heat stress, two key enzymes - ubiquitin-activating enzyme (E1) and ubiquitin-conjugating enzyme (E2) - of the Ubiquitin/26S proteasome pathway (UPP) were studied in three strains of G. lemaneiformis-wild type, heat-tolerant cultivar 981 and heat-tolerant cultivar 07-2. The full length DNA sequence of E1 contained only one exon. The open reading frame (ORF) sequence was 981 nucleotides encoding 326 amino acids, which contained conserved ATP binding sites (LYDRQIRLWGLE, ELAKNVLLAGV, LKEMN, VVCAI) and the ubiquitin-activating domains (VVCAI…LMTEAC, VFLDLGDEYSYQ, AIVGGMWGRE). The gene sequence of E2 contained four exons and three introns. The sum of the four exons gave an open reading frame sequence of 444 nucleotides encoding 147 amino acids, which contained a conserved ubiquitin-activating domain (GSICLDIL), ubiquitin-conjugating domains (RIYHPNIN, KVLLSICSLL, DDPLV) and ubiquitin-ligase (E3) recognition sites (KRI, YPF, WSP). Real-time-PCR analysis of transcription levels of E1 and E2 under heat shock conditions (28°C and 32°C) showed that in wild type, transcriptions of E1 and E2 were up-regulated at 28°C, while at 32°C, transcriptions of the two enzymes were below the normal level. In cultivar 981 and cultivar 07-2 of G. lemaneiformis, the transcription levels of the two enzymes were up-regulated at 32°C, and transcription level of cultivar 07-2 was even higher than that of cultivar 981. These results suggest that the UPP plays an important role in high temperature resistance of G. lemaneiformis and the bioactivity of UPP is directly related to the heat-resistant ability of G. lemaneiformis.

  20. Activation and afterheat analysis for CH HCSB TBM

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi; FENG Kai-ming; ZHANG Guo-shu; YUAN Tao

    2006-01-01

    With an activation calculation code FDKR and decay chain data library AF-DCDLIB, the radioactivity,afterheat decay and Biological Hazard Potential (BHP) from activation products have been analyzed in the CH HCSB TBM. The calculation results show that the total radioactivity inventory, heat decay and BHP are 2.10×1016Bq、5.06×10-3 MW、68.6 km3·(Kw)-1,respectively, at shutdown after a continuous irradiation over 0.53 years with 500 MW fusion power.It shows that there isn't seriously environmental safety issue in the TBM.

  1. Electrospun magnetic nanofibre mats - A new bondable biomaterial using remotely activated magnetic heating

    Science.gov (United States)

    Zhong, Yi; Leung, Victor; Yuqin Wan, Lynn; Dutz, Silvio; Ko, Frank K.; Häfeli, Urs O.

    2015-04-01

    A solvothermal process was adopted to produce hydrophilic magnetite (Fe3O4) nanoparticles which were subsequently emulsified with a chloroform/methanol (70/30 v/v) solution of poly(caprolactone) (PCL) and then electrospun into a 0.2 mm thick PCL mat. The magnetic heating of the mats at a field amplitude of 25 kA/m and frequency of 400 kHz exhibited promising efficiency for magnetic hyperthermia, with a specific absorption rate of about 40 W/g for the magnetic mat. The produced heat was used to melt the magnetic mat onto the surrounding non-magnetic polymer mat from within, without destroying the nanostructure of the non-magnetic polymer more than 0.5 mm away. Magnetic nanofibre mats might thus be useful for internal heat sealing applications, and potentially also for thermotherapy.

  2. Electrospun magnetic nanofibre mats – A new bondable biomaterial using remotely activated magnetic heating

    International Nuclear Information System (INIS)

    A solvothermal process was adopted to produce hydrophilic magnetite (Fe3O4) nanoparticles which were subsequently emulsified with a chloroform/methanol (70/30 v/v) solution of poly(caprolactone) (PCL) and then electrospun into a 0.2 mm thick PCL mat. The magnetic heating of the mats at a field amplitude of 25 kA/m and frequency of 400 kHz exhibited promising efficiency for magnetic hyperthermia, with a specific absorption rate of about 40 W/g for the magnetic mat. The produced heat was used to melt the magnetic mat onto the surrounding non-magnetic polymer mat from within, without destroying the nanostructure of the non-magnetic polymer more than 0.5 mm away. Magnetic nanofibre mats might thus be useful for internal heat sealing applications, and potentially also for thermotherapy

  3. Heat-stimulated exoelectron emission of uranium activated crystals of lithium and sodium fluorides

    International Nuclear Information System (INIS)

    Heat-stimulated exoelectron emission of LiF-U, Cu; LiF, Sr; NaF-U, Sr monocrystals after irradiation by 1 keV electrons for 1 s at current density of 1 μA/cm2 and heating at a rate of 20 K/s was studied. New high-temperature peaks were detected and parameters of heat-stimulated exoelectron emission were determined. It was pointed out that dose dependence of the emission peak intensity has a linear section up to ∼ 103 Gy. It suggests potentiality of (Li, Na) F-U, Me crystals application as high-temperature thermo-emission dosemeters for radiation situation monitoring, for instance, in radioactive waste storage

  4. Electrospun magnetic nanofibre mats – A new bondable biomaterial using remotely activated magnetic heating

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yi [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Key Laboratory of Science & Technology of Eco-Textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai (China); Leung, Victor; Yuqin Wan, Lynn [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Dutz, Silvio [Institut für Biomedizinische Technik und Informatik, Technische Universität Ilmenau (Germany); Department of Nano Biophotonics, Leibniz Institute of Photonic Technology, Jena (Germany); Ko, Frank K., E-mail: frank.ko@ubc.ca [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Häfeli, Urs O., E-mail: urs.hafeli@ubc.ca [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver (Canada)

    2015-04-15

    A solvothermal process was adopted to produce hydrophilic magnetite (Fe{sub 3}O{sub 4}) nanoparticles which were subsequently emulsified with a chloroform/methanol (70/30 v/v) solution of poly(caprolactone) (PCL) and then electrospun into a 0.2 mm thick PCL mat. The magnetic heating of the mats at a field amplitude of 25 kA/m and frequency of 400 kHz exhibited promising efficiency for magnetic hyperthermia, with a specific absorption rate of about 40 W/g for the magnetic mat. The produced heat was used to melt the magnetic mat onto the surrounding non-magnetic polymer mat from within, without destroying the nanostructure of the non-magnetic polymer more than 0.5 mm away. Magnetic nanofibre mats might thus be useful for internal heat sealing applications, and potentially also for thermotherapy.

  5. Heating of vegetable oils influences the activity of enzymes participating in arachidonic acid formation in Wistar rats.

    Science.gov (United States)

    Stawarska, Agnieszka; Białek, Agnieszka; Tokarz, Andrzej

    2015-10-01

    Dietary intake of lipids and their fatty acids profile influence many aspects of health. Thermal processing changes the properties of edible oils and can also modify their metabolism, for example, eicosanoids formation. The aim of our study was to verify whether the activity of desaturases can be modified by lipids intake, especially by the fatty acids content. The experimental diets contained rapeseed oil, sunflower oil, and olive oil, both unheated and heated (for 10 minutes at 200 °C each time before administration), and influenced the fatty acids composition in serum and the activity of enzymes participating in arachidonic acid (AA) formation. The activity of desaturases was determined by measuring the amounts of AA formed in vitro derived from linoleic acid as determined in liver microsomes of Wistar rats. In addition, the indices of ∆(6)-desaturase (D6D) and ∆(5)-desaturase (D5D) have been determined. To realize this aim, the method of high-performance liquid chromatography has been used with ultraviolet-visible spectrophotometry detection. Diet supplementation with the oils rich in polyunsaturated fatty acids affects the fatty acids profile in blood serum and the activity of D6D and ∆(5)-desaturase in rat liver microsomes, the above activities being dependent on the kind of oil applied. Diet supplementation with heated oils has been found to increase the amount of AA produced in hepatic microsomes; and in the case of rapeseed oil and sunflower oil, it has also increased D6D activity.

  6. Modification of Activated Carbon by Means of Microwave Heating and Its Effects on the Pore Texture and Surface Chemistry

    Directory of Open Access Journals (Sweden)

    Liqiang Zhang

    2013-02-01

    Full Text Available Two kinds of typical activated carbons (coal based AC and coconut shell based AC were modified in a flow of N2 gas has been carried out using a microwave device operating at 2450 MHz and different input power, instead of a conventional furnace. The samples were analyzed by means of low temperature N2 adsorption, elemental analysis and Boehm titration. The results show that microwave heating is an effective means of activated carbon modification. The temperature of activated carbon increases rapidly under microwave heating and then gradual increase to a quasi-stationary temperature. The pore texture of activated carbon changes slightly after microwave treatment and the two activated carbons still keep rich pore structure. The oxygen functional groups decompose and evolve with the form of CO and CO2. This in turn gives rise to a significant decrease in oxygen content. These changes of oxygen contents increase as the microwave input power increases. During microwave treatment, a gradual decrease in the surface acidic functional groups is observed. More important, with the removal of the surface acidic groups, the number of the basic group increased gradually, the activated carbon with oxygen functional groups become basic properties material.

  7. Modification of Activated Carbon by Means of Microwave Heating and Its Effects on the Pore Texture and Surface Chemistry

    Directory of Open Access Journals (Sweden)

    Bing Li

    2013-02-01

    Full Text Available Two kinds of typical Activated Carbons (coal based AC and coconut shell based AC were modified in a flow of N0 gas has been carried out using a microwave device operating at 2450 MHz and different input power, instead of a conventional furnace. The samples were analyzed by means of low temperatureN0 adsorption, elemental analysis and Boehm titration. The results show that microwave heating is an effective means of activated carbon modification. The temperature of activated carbon increases rapidly under microwave heating and then gradual increase to a quasi-stationary temperature. The pore texture of activated carbon changes slightly after microwave treatment and the two activated carbons still keep rich pore structure. The oxygen functional groups decompose and evolve with the form of CO and CO2. This in turn gives rise to a significant decrease in oxygen content. These changes of oxygen contents increase as the microwave input power increases. During microwave treatment, a gradual decrease in the surface acidic functional groups is observed. More important, with the removal of the surface acidic groups, the number of the basic group increased gradually, the activated carbon with oxygen functional groups become basic properties material.

  8. The evolution of a decaying spheromak

    Science.gov (United States)

    Sgro, A. G.; Mirin, A. A.; Marklin, G.

    1987-10-01

    The evolution of a low beta spheromak initially in a two-dimensional stable equilibrium having a constant J/B (the so-called minimum energy state) is calculated within the context of resistive magnetohydrodynamics. Since the initial equilibrium is stable, the spheromak at first resistively evolves through a sequence of stable quasiequilibria. This phase of the evolution is calculated with a transport code in which the resistivity is assumed to be largest at the wall and lowest at the magnetic axis. Resistive diffusion causes the safety factor q to decrease everywhere while decreasing fastest near the wall. The quasiequilibria through which the spheromak evolves are tested for stability with both an ideal linear stability code and a resistive one. The results of both stability codes are in basic agreement and show that when q drops to below (1)/(2) everywhere the spheromak becomes unstable to an n=2 mode. The agreement of the stability codes implies that the unstable mode is a resistively modified ideal mode. The unstable equilibrium is used as the initial condition in a 3-D nonlinear magnetohydrodynamic simulation. This simulation shows that after the unstable mode saturates, the spheromak resistively evolves through a sequence of three-dimensional quasiequilibria until it reaches another unstable configuration, after which it approaches the 2-D minimum energy state again. This evolutionary cycle can conceivably start again, unless the cycle time becomes comparable to the configuration decay time, which happens at high S. One consequence of the evolutionary cycle is that as the 3-D spheromak approaches the minimum energy state, the magnetic axis and hot plasma near it approach the wall and a new magnetic axis is formed. At high enough S, when the cycle time is comparable to the configuration lifetime, this convective heat loss mechanism is minimized. The 3-D code predicts that only the n=0 and n=2 modes are active. Simulations in which the n=1, 3, and 4 modes are

  9. Simulation studies of neutron-induced background for 0νββ decay in 124Sn from underground rock activity at INO

    International Nuclear Information System (INIS)

    The TIN,TIN detector (The INdia-based TIN detector) comprising cryogenic bolometer array of Tin detector elements is under development for a feasibility study to search for 0νββ decay in 124Sn. Given the rarity of the process of 0νββ decay where T1/2 > 1020 yrs, understanding and minimization of background is very important. Of the different sources of background, neutrons are the most difficult to suppress and hence crucial to understand. It is crucial to estimate the contribution of neutron induced background in an underground laboratory and from the surrounding detector materials. The simulation studies for neutron spectra in the INO cavern and the shield design have been initiated. Some of the results are presented here

  10. CLEO Results B Decays

    CERN Document Server

    Cassel, David G

    2001-01-01

    Measurements of many Standard Model constants are clouded by uncertainties in nonperturbative QCD parameters that relate measurable quantities to the underlying parton-level processes. Generally these QCD parameters have been obtained from model calculations with large uncertainties that are difficult to quantify. The CLEO Collaboration has taken a major step towards reducing these uncertainties in determining the CKM matrix elements Vcb and Vub using new measurements of the branching fraction and photon energy spectrum of B -> s gamma decays. This report includes: the new CLEO measurements of B -> s gamma decays, Vcb, and Vub; the first results from CLEO III data -- studies of B -> K pi, pi pi, and K Kbar decays; mention of some other recent CLEO B decay results; and plans for operating CESR and CLEO in the charm threshold region.

  11. Decay ring design

    CERN Document Server

    Chancé, A; Bouquerel, E; Hancock, S; Jensen, E

    The study of the neutrino oscillation between its different flavours needs pureand very intense fluxes of high energy, well collimated neutrinos with a welldetermined energy spectrum. A dedicated machine seems to be necessarynowadays to reach the required flux. A new concept based on the β-decayof radioactive ions which were accelerated in an accelerator chain was thenproposed. After ion production, stripping, bunching and acceleration, the unstableions are then stored in a racetrack-shaped superconducting decay ring.Finally, the ions are accumulated in the decay ring until being lost. The incomingbeam is merged to the stored beam by using a specific RF system, whichwill be presented here.We propose here to study some aspects of the decay ring, such as its opticalproperties, its RF system or the management of the losses which occur in thering (mainly by decay or by collimation).

  12. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  13. Inflaton decay in supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Endo, M.; Takahashi, F. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yanagida, T.T. [Tokyo Univ. (Japan). Dept. of Physics]|[Tokyo Univ. (Japan). Research Center for the Early Universe

    2007-06-15

    We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton generically decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. We derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. Furthermore, the inflaton naturally decays into the visible sector via the top Yukawa coupling and SU(3){sub C} gauge interactions. (orig.)

  14. The Influence of Oil Heat Treatment on Wood Decay Resistance by Fourier Inf rared Spectrum Analysis%利用傅里叶变换红外光谱分析油热处理对木材耐腐性能的影响

    Institute of Scientific and Technical Information of China (English)

    王雅梅; 马淑玲; 冯利群

    2014-01-01

    木材防腐处理可改善人工林木材易腐朽、虫蛀等缺陷,其中热处理方法不仅环保无污染,还可提高木材耐腐性、尺寸稳定性等。研究以植物油为导热介质对杨木和樟子松进行油浴热处理,对热处理木材进行室内耐腐性能研究,通过傅里叶变换红外光谱分析处理前后木材化学组分的变化,分析热处理对木材耐腐性能的影响及主要作用机制。结果表明:经过油热处理杨木的质量损失率由未处理材的19.37%下降至5%,樟子松的质量损失率由未处理材的8.23%下降至3.15%,油热处理可以有效提高木材的耐腐性能。木材腐朽菌之所以能够在木材中生长繁殖从而败坏木材,是因为木材能够提供木材腐朽菌比较好的生存条件,如营养物质、水分、氧气等,而木材中的纤维素、半纤维素等是木材腐朽菌的主要营养来源。由红外光谱分析可知,热处理后木材中羟基等亲水性基团大量减少,吸水性减弱,减少了木腐菌生长所必需的水分;热处理后木材的纤维素、半纤维素等化学组分发生了降解,减少了木腐菌生长需要的营养物质。油热处理可以减少纤维素、半纤维素等木腐菌的营养物质,从而达到了提高木材耐腐性能的目的。%Wood preservative treatment can improve defects of plantation wood such as easy to corrupt and moth eaten .Among them heat-treatment is not only environmental and no pollution ,also can improve the corrosion resistance and dimension stability of wood .In this test Poplar and Mongolian Seoteh Pine was treated by soybean oil as heat-conducting medium ,and the heat treatment wood was studied for indoor decay resistance ;wood chemical components before and after treatment ,the effect of heat treatment on wood decay resistance performance and main mechanism of action were analysed by Fourier infrared spectrometric . Results showed that the mass loss

  15. Open Flavor Strong Decays

    Science.gov (United States)

    García-Tecocoatzi, H.; Bijker, R.; Ferretti, J.; Galatà, G.; Santopinto, E.

    2016-10-01

    In this contribution, we discuss the results of a QM calculation of the open-flavor strong decays of **** light nucleon resonances. These are the results of a recent calculation, where we used a modified ^3P_0 model for the amplitudes and the U(7) algebraic model and the hypercentral quark model to predict the baryon spectrum. The decay amplitudes are compared with the existing experimental data.

  16. Aspects of B decays

    Energy Technology Data Exchange (ETDEWEB)

    Faller, Sven

    2011-03-04

    B-meson decays are a good probe for testing the flavour sector of the standard model of particle physics. The standard model describes at present all experimental data satisfactorily, although some ''tensions'' exist, i.e. two to three sigma deviations from the predictions, in particular in B decays. The arguments against the standard model are thus purely theoretical. These tensions between experimental data and theoretical predictions provide an extension of the standard model by new physics contributions. Within the flavour sector main theoretical uncertainties are related to the hadronic matrix elements. For exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays QCD sum rule techniques, which are suitable for studying hadronic matrix elements, however, with substantial, but estimable hadronic uncertainties, are used. The exploration of new physics effects in B-meson decays is done in an twofold way. In exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays the effect of additional right-handed vector as well as left- and right-handed scalar and tensor hadronic current structures in the decay rates and the form factors are studied at the non-recoil point. As a second approach one studied the non-leptonic B{sup 0}{sub s}{yields}J/{psi}{phi} and B{sup 0}{yields}J/{psi}K{sub S,L} decays discussing CP violating effects in the time-dependent decay amplitudes by considering new physics phase in the B{sup 0}- anti B{sup 0} mixing phase. (orig.)

  17. Open flavor strong decays

    CERN Document Server

    García-Tecocoatzi, H; Ferretti, J; Galatà, G; Santopinto, E

    2016-01-01

    In this contribution, we discuss the results of a QM calculation of the open-flavor strong decays of **** light nucleon resonances. These are the results of a recent calculation, where we used a modified $^3P_0$ model for the amplitudes and the U(7) algebraic model and the Hypercentral Quark Model to predict the baryon spectrum. The decay amplitudes are compared with the existing experimental data.

  18. Laboratory Activity: Specific Heat by Change in Internal Energy of Silly Putty

    Science.gov (United States)

    Koser, John

    2011-01-01

    Students in introductory physics courses often don't study thermodynamics or thermodynamic events. If any thermal physics is taught in introductory courses (e.g., Physics 101 for Liberal Arts Majors), it usually involves the concepts of specific heat and various temperature scales. Seldom are the first and second laws of thermodynamics taught in…

  19. Design and development of a shape memory alloy activated heat pipe-based thermal switch

    Science.gov (United States)

    Benafan, O.; Notardonato, W. U.; Meneghelli, B. J.; Vaidyanathan, R.

    2013-10-01

    This work reports on the design, fabrication and testing of a thermal switch wherein the open and closed states were actuated by shape memory alloy (SMA) elements while heat was transferred by a two-phase heat pipe. The motivation for such a switch comes from NASA’s need for thermal management in advanced spaceport applications associated with future lunar and Mars missions. As the temperature can approximately vary between -233 and 127 ° C during lunar day/night cycles, the switch was designed to reject heat from a cryogen tank into space during the night cycle while providing thermal isolation during the day cycle. A Ni47.1Ti49.6Fe3.3 (at.%) alloy that exhibited a reversible phase transformation between a trigonal R-phase and a cubic austenite phase was used as the sensing and actuating elements. Thermomechanical actuation, accomplished through an antagonistic spring system, resulted in strokes up to 7 mm against bias forces of up to 45 N. The actuation system was tested for more than thirty cycles, equivalent to one year of operation. The thermal performance, accomplished via a variable length, closed two-phase heat pipe, was evaluated, resulting in heat transfer rates of 13 W using pentane and 10 W using R-134a as working fluids. Experimental data were also compared to theoretical predictions where possible. Direct comparisons between different design approaches of SMA helical actuators, highlighting the effects of the helix angle, were carried out to give a layout of more accurate design methodologies.

  20. Reduction in Activity/Gene Expression of Anthocyanin Degradation Enzymes in Lychee Pericarp is Responsible for the Color Protection of the Fruit by Heat and Acid Treatment

    Institute of Scientific and Technical Information of China (English)

    FANG Fang; ZHANG Zhao-qi; ZHANG Xue-lian; WU Zhen-xian; YIN Hui-fang; PANG Xue-qun

    2013-01-01

    Heat and acid treatments were reported to be a promising substitute for SO2 fumigation in color protection of postharvest lychee (Litchi chinensis Sonn.) fruits, but the mechanism was not clear. In the present study, hot water (70°C) dipping followed by immersion in 2%HCl (heat-acid) substantially protected the red color of the fruit during storage at 25°C and inhibited anthocyanin degradation while hot water dipping alone (heat) led to rapidly browning and about 90%loss in anthocyanin content. The pH values in the pericarp of the heat-acid treated fruit dropped to 3.2, while the values maintained around 5.0 in the heat-treated and control fruit. No significantly different pH values were detected among the arils of heat-acid, heat treated and control fruit. Heat-acid treatment dramatically reduced the activities of anthocyanin degradation enzyme (ADE), peroxidase (POD) and polyphenol oxidase in the pericarp. A marked reduction in LcPOD gene expression was also detected in heat-acid treated fruit, in contrast, induction was found in heat treated fruit. The pericarp of heat-acid treated fruit exhibited significantly lower respiration rate but faster water loss than that of the untreated or heat treated fruit. Taken together, heat treatment triggered quick browning and anthocyanin loss in lychee fruit, while heat-acid treatment protected the fruit color by a great reduction in the activities/gene expression of anthocyanin degradation enzymes and acidification of lychee pericarp.

  1. Influence of salicylic and succinic acids on antioxidant enzymes activity, heat resistance and productivity of Panicum miliaceum L.

    Directory of Open Access Journals (Sweden)

    Miroshnichenko N.N.

    2011-05-01

    Full Text Available The influence of treatment of millet (Panicum miliaceum L. seeds with the solutions of salicylic and succinic acids on the heat resistance of plantlets and activity of antioxidant enzymes – superoxide dismutase (SOD, catalase and peroxidase – in them have been investigated. In the micro-field experiment the influence of these acids on the millet yield was estimated. The action of salicylic (10 μM and succinic (1 mM acids caused the increase of plantlets resistance to the damaging heating that expressed in the rise of relative quantity of survived plantlets in 5 days after heating at the temperature of 47°С and in the reduced content of lipid peroxidation product malonic dialdehyde during the poststress period. The increase of activity of SOD, catalase and peroxidase took place in millet plantlets under the influence of salicylic and succinic acids. The increase of productivity of millet grain under the action of salicylic and succinic acids on 13,3-52,0 and 6,4-38,8% respectively depending on weather conditions in the field experiments was noted.

  2. Vibro-fluidized bed heat pump drying of mint leaves with respect to phenolic content, antioxidant activity, and color indices

    Directory of Open Access Journals (Sweden)

    Ataei Ardestani Seyed Majid

    2015-01-01

    Full Text Available Because of high porosity and stickiness of mint leaves, they could not be fluidized well during fluidization. In this study, a vibro-fluidized bed dryer assisted heat pump system was designed and fabricated to overcome this problem. The drying experiments were carried out at temperatures of 40, 50 and 60 °C. The quality of the dehydrated samples was assessed based on color indices, antioxidant activity, and total phenolic content. Drying process primarily occurred in falling rate period. The effective coefficient of moisture transfer of the samples was increased with air temperature and varied from 4.26656×10-11 to 2.95872×10-10 m2 s-1 for heat pump drying (HPD method, and 3.71918×10-11 to 1.29196×10-10 m2 s-1 for none-heat pump drying (NHPD method. The color indices for temperatures of 40 and 50 °C were very close to each other, whereas by increasing temperature to 60 °C, a remarkable loss of green color was observed. The highest phenolic content was found in methanolic extract for HPD at 60 °C, and NHPD at 50 °C contained the lowest amount of phenolic compounds. NHPD treatments showed lower antioxidant activity compared to HPD treatments at the same temperature due to the longer drying times.

  3. Pervasive faint Fe XIX emission from a solar active region observed with EUNIS-13: Evidence for nanoflare heating

    Energy Technology Data Exchange (ETDEWEB)

    Brosius, Jeffrey W. [Catholic University of America at NASA Goddard Space Flight Center, Solar Physics Laboratory, Code 671, Greenbelt, MD 20771 (United States); Daw, Adrian N. [NASA Goddard Space Flight Center, Solar Physics Laboratory, Code 671, Greenbelt, MD 20771 (United States); Rabin, D. M., E-mail: Jeffrey.W.Brosius@nasa.gov [NASA Goddard Space Flight Center, Heliophysics Science Division, Code 670, Greenbelt, MD 20771 (United States)

    2014-08-01

    We present spatially resolved EUV spectroscopic measurements of pervasive, faint Fe XIX 592.2 Å line emission in an active region observed during the 2013 April 23 flight of the Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS-13) sounding rocket instrument. With cooled detectors, high sensitivity, and high spectral resolution, EUNIS-13 resolves the lines of Fe XIX at 592.2 Å (formed at temperature T ≈ 8.9 MK) and Fe XII at 592.6 Å (T ≈ 1.6 MK). The Fe XIX line emission, observed over an area in excess of 4920 arcsec{sup 2} (2.58 × 10{sup 9} km{sup 2}, more than 60% of the active region), provides strong evidence for the nanoflare heating model of the solar corona. No GOES events occurred in the region less than 2 hr before the rocket flight, but a microflare was observed north and east of the region with RHESSI and EUNIS during the flight. The absence of significant upward velocities anywhere in the region, particularly the microflare, indicates that the pervasive Fe XIX emission is not propelled outward from the microflare site, but is most likely attributed to localized heating (not necessarily due to reconnection) consistent with the nanoflare heating model of the solar corona. Assuming ionization equilibrium we estimate Fe XIX/Fe XII emission measure ratios of ∼0.076 just outside the AR core and ∼0.59 in the core.

  4. Pervasive faint Fe XIX emission from a solar active region observed with EUNIS-13: Evidence for nanoflare heating

    International Nuclear Information System (INIS)

    We present spatially resolved EUV spectroscopic measurements of pervasive, faint Fe XIX 592.2 Å line emission in an active region observed during the 2013 April 23 flight of the Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS-13) sounding rocket instrument. With cooled detectors, high sensitivity, and high spectral resolution, EUNIS-13 resolves the lines of Fe XIX at 592.2 Å (formed at temperature T ≈ 8.9 MK) and Fe XII at 592.6 Å (T ≈ 1.6 MK). The Fe XIX line emission, observed over an area in excess of 4920 arcsec2 (2.58 × 109 km2, more than 60% of the active region), provides strong evidence for the nanoflare heating model of the solar corona. No GOES events occurred in the region less than 2 hr before the rocket flight, but a microflare was observed north and east of the region with RHESSI and EUNIS during the flight. The absence of significant upward velocities anywhere in the region, particularly the microflare, indicates that the pervasive Fe XIX emission is not propelled outward from the microflare site, but is most likely attributed to localized heating (not necessarily due to reconnection) consistent with the nanoflare heating model of the solar corona. Assuming ionization equilibrium we estimate Fe XIX/Fe XII emission measure ratios of ∼0.076 just outside the AR core and ∼0.59 in the core.

  5. Thermoregulation of water foraging honeybees--balancing of endothermic activity with radiative heat gain and functional requirements.

    Science.gov (United States)

    Kovac, Helmut; Stabentheiner, Anton; Schmaranzer, Sigurd

    2010-12-01

    Foraging honeybees are subjected to considerable variations of microclimatic conditions challenging their thermoregulatory ability. Solar heat is a gain in the cold but may be a burden in the heat. We investigated the balancing of endothermic activity with radiative heat gain and physiological functions of water foraging Apis mellifera carnica honeybees in the whole range of ambient temperatures (T(a)) and solar radiation they are likely to be exposed in their natural environment in Middle Europe. The mean thorax temperature (T(th)) during foraging stays was regulated at a constantly high level (37.0-38.5 °C) in a broad range of T(a) (3-30 °C). At warmer conditions (T(a)=30-39 °C) T(th) increased to a maximal level of 45.3 °C. The endothermic temperature excess (difference of T(body)-T(a) of living and dead bees) was used to assess the endogenously generated temperature elevation as a correlate of energy turnover. Up to a T(a) of ∼30 °C bees used solar heat gain for a double purpose: to reduce energetic expenditure and to increase T(th) by about 1-3 °C to improve force production of flight muscles. At higher T(a) they exhibited cooling efforts to get rid of excess heat. A high T(th) also allowed regulation of the head temperature high enough to guarantee proper function of the bees' suction pump even at low T(a). This shortened the foraging stays and this way reduced energetic costs. With decreasing T(a) bees also reduced arrival body weight and crop loading to do both minimize costs and optimize flight performance. PMID:20705071

  6. Improving high temperature creep resistance of reduced activation steels by addition of nitrogen and intermediate heat treatment

    Science.gov (United States)

    Liu, W. B.; Zhang, C.; Xia, Z. X.; Yang, Z. G.

    2014-12-01

    In the present study, we report an enhanced high-temperature creep resistance in reduced activation ferrite/martensite (RAFM) steels, by introducing nitrogen (0.035 wt%, M3 steel) and employing a novel intermediate heat treatment I-Q-T (intermediate treatment, quenching and tempering). In comparison with all the control groups, the uniaxial tests of the I-Q-T treated M3 steel showed significant increase in rupture time and decrease in elongation. The microstructures of the samples were further characterized to elucidate the origin of the enhanced creep resistance. It is found that, by introducing nitrogen, the primary TaC particles were refined; by employing the I-Q-T heat treatment, the dispersed fine secondary MX precipitates, as well as the lath subgrains containing high-density dislocations, were increased: all are responsible for the improved creep resistance.

  7. Antioxidant and Antiproliferative Activities of Heated Sterilized Pepsin Hydrolysate Derived from Half-Fin Anchovy (Setipinna taty

    Directory of Open Access Journals (Sweden)

    Dongfeng Wang

    2011-06-01

    Full Text Available In this paper we studied the antioxidant and antiproliferative activities of the heated pepsin hydrolysate from a marine fish half-fin anchovy (HAHp-H. Furthermore, we compared the chemical profiles including the amino acid composition, the browning intensity, the IR and UV-visible spectra, and the molecular weight distribution between the half-fin anchovy pepsin hydrolysate (HAHp and HAHp-H. Results showed that heat sterilization on HAHp improved the 1,1-diphenyl-2-picryl-hydrazil (DPPH radical-scavenging activity and reducing power. In addition, the antiproliferative activities were all increased for HAHp-H on DU-145 human prostate cancer cell line, 1299 human lung cancer cell line and 109 human esophagus cancer cell line. The contents of free amino acid and reducing sugar of HAHp-H were decreased (P < 0.05. However, hydrophobic amino acid residues and the browning intensity of HAHp-H were increased. FT-IR spectroscopy indicated that amide I and amide III bands of HAHp-H were slightly modified, whereas band intensity of amide II was reduced dramatically. Thermal sterilization resulted in the increased fractions of HAHp-H with molecular weight of 3000–5000 Da and below 500 Da. The enhanced antioxidant and antiproliferative activities of HAHp-H might be attributed to the Maillard reaction.

  8. Heat treatment of curdlan enhances the enzymatic production of biologically active β-(1,3)-glucan oligosaccharides.

    Science.gov (United States)

    Kumagai, Yuya; Okuyama, Masayuki; Kimura, Atsuo

    2016-08-01

    Biologically active β-(1,3)-glucan oligosaccharides were prepared from curdlan using GH64 enzyme (KfGH64). KfGH64 showed low activity toward native curdlan; thereby pretreatment conditions of curdlan were evaluated. KfGH64 showed the highest activity toward curdlan with heat treatment. The most efficient pretreatment (90°C for 0.5h) converted approximately 60% of curdlan into soluble saccharides under the optimized enzyme reaction conditions (pH 5.5, 37°C, 100rpm mixing speed, 24h, and 10μg of KfGH64/1g of curdlan). The resulting products were predominantly laminaripentaose and a small amount of β-(1,3)-glucans with an average degree of polymerization (DP) of 13 and 130. The products did not contain small oligosaccharides (DPhydrolysis of heat-treated curdlan by KfGH64 is a suitable method for the production of biologically active β-(1,3)-glucan oligosaccharides. PMID:27112889

  9. mTOR is essential for the proteotoxic stress response, HSF1 activation and heat shock protein synthesis.

    Directory of Open Access Journals (Sweden)

    Shiuh-Dih Chou

    Full Text Available The target of rapamycin (TOR is a high molecular weight protein kinase that regulates many processes in cells in response to mitogens and variations in nutrient availability. Here we have shown that mTOR in human tissue culture cells plays a key role in responses to proteotoxic stress and that reduction in mTOR levels by RNA interference leads to increase sensitivity to heat shock. This effect was accompanied by a drastic reduction in ability to synthesize heat shock proteins (HSP, including Hsp70, Hsp90 and Hsp110. As HSP transcription is regulated by heat shock transcription factor 1 (HSF1, we examined whether mTOR could directly phosphorylate this factor. Indeed, we determined that mTOR could directly phosphorylate HSF1 on serine 326, a key residue in transcriptional activation. HSF1 was phosphorylated on S326 immediately after heat shock and was triggered by other cell stressors including proteasome inhibitors and sodium arsenite. Null mutation of S326 to alanine led to loss of ability to activate an HSF1-regulated promoter-reporter construct, indicating a direct role for mTOR and S326 in transcriptional regulation of HSP genes during stress. As mTOR is known to exist in at least two intracellular complexes, mTORC1 and mTOR2 we examined which complex might interact with HSF1. Indeed mTORC1 inhibitor rapamycin prevented HSF1-S326 phosphorylation, suggesting that this complex is involved in HSF1 regulation in stress. Our experiments therefore suggest a key role for mTORC1 in transcriptional responses to proteotoxic stress.

  10. A review of health, planning, insurance and property value issues related to active solar heating systems

    International Nuclear Information System (INIS)

    The research reported here considers the potential health risks, local authority planning implications, insurance and property value aspects of solar water heating systems. The United Kingdom market for this technology is also discussed. Methodologies employed, including literature reviews, telephone and postal survey and re-analysis of a 1995 survey, are explained. No major problems are identified in any of the target areas although recommendations for water temperature management and coordinated local authority policies on renewable energy are given. (UK)

  11. Heat production and quantitative oxidation of nutrients by physical activity in pigs

    DEFF Research Database (Denmark)

    Jakobsen, K; Chwalibog, André; Henckel, S;

    1994-01-01

    Two groups of pigs weighing 90 (Expt A) or 80 (Expt B) kg walked on a horizontal moving rubber belt for a distance of 315 m at a speed of 25.6 +/- 0.38 and 28.8 +/- 0.35 m/min respectively for 10 min in an open-air-circuit respiration unit. From measurements of VO2 and VCO2, heat production...

  12. Photothermally Activated Pyroelectric Polymer Films for Harvesting of Solar Heat with a Hybrid Energy Cell Structure.

    Science.gov (United States)

    Park, Teahoon; Na, Jongbeom; Kim, Byeonggwan; Kim, Younghoon; Shin, Haijin; Kim, Eunkyoung

    2015-12-22

    Photothermal effects in poly(3,4-ethylenedioxythiophene)s (PEDOTs) were explored for pyroelectric conversion. A poled ferroelectric film was coated on both sides with PEDOT via solution casting polymerization of EDOT, to give highly conductive and effective photothermal thin films of PEDOT. The PEDOT films not only provided heat source upon light exposure but worked as electrodes for the output energy from the pyroelectric layer in an energy harvester hybridized with a thermoelectric layer. Compared to a bare thermoelectric system under NIR irradiation, the photothermal-pyro-thermoelectric device showed more than 6 times higher thermoelectric output with the additional pyroelectric output. The photothermally driven pyroelectric harvesting film provided a very fast electric output with a high voltage output (Vout) of 15 V. The pyroelectric effect was significant due to the transparent and high photothermal PEDOT film, which could also work as an electrode. A hybrid energy harvester was assembled to enhance photoconversion efficiency (PCE) of a solar cell with a thermoelectric device operated by the photothermally generated heat. The PCE was increased more than 20% under sunlight irradiation (AM 1.5G) utilizing the transmitted light through the photovoltaic cell as a heat source that was converted into pyroelectric and thermoelectric output simultaneously from the high photothermal PEDOT electrodes. Overall, this work provides a dynamic and static hybrid energy cell to harvest solar energy in full spectral range and thermal energy, to allow solar powered switching of an electrochromic display. PMID:26308669

  13. Manufacturing and thermomechanical testing of actively cooled all beryllium high heat flux test pieces

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, N.N.; Sokolov, Yu.A.; Shatalov, G.E. [and others

    1995-09-01

    One of the problems affiliated to ITER high heat flux elements development is a problem of interface of beryllium protection with heat sink routinely made of copper alloys. To get rid of this problem all beryllium elements could be used as heat receivers in places of enhanced thermal loads. In accordance with this objectives four beryllium test pieces of two types have been manufactured in {open_quotes}Institute of Beryllium{close_quotes} for succeeding thermomechanical testing. Two of them were manufactured in accordance with JET team design; they are round {open_quotes}hypervapotron type{close_quotes} test pieces. Another two ones are rectangular test sections with a twisted tape installed inside of the circular channel. Preliminary stress-strain analysis have been performed for both type of the test pieces. Hypervapotrons have been shipped to JET where they were tested on JET test bed. Thermomechanical testing of pieces of the type of {open_quotes}swirl tape inside of tube{close_quotes} have been performed on Kurchatov Institute test bed. Chosen beryllium grade properties, some details of manufacturing, results of preliminary stress-strain analysis and thermomechanical testing of the test pieces {open_quotes}swirl tape inside of tube{close_quotes} type are given in this report.

  14. Photothermally Activated Pyroelectric Polymer Films for Harvesting of Solar Heat with a Hybrid Energy Cell Structure.

    Science.gov (United States)

    Park, Teahoon; Na, Jongbeom; Kim, Byeonggwan; Kim, Younghoon; Shin, Haijin; Kim, Eunkyoung

    2015-12-22

    Photothermal effects in poly(3,4-ethylenedioxythiophene)s (PEDOTs) were explored for pyroelectric conversion. A poled ferroelectric film was coated on both sides with PEDOT via solution casting polymerization of EDOT, to give highly conductive and effective photothermal thin films of PEDOT. The PEDOT films not only provided heat source upon light exposure but worked as electrodes for the output energy from the pyroelectric layer in an energy harvester hybridized with a thermoelectric layer. Compared to a bare thermoelectric system under NIR irradiation, the photothermal-pyro-thermoelectric device showed more than 6 times higher thermoelectric output with the additional pyroelectric output. The photothermally driven pyroelectric harvesting film provided a very fast electric output with a high voltage output (Vout) of 15 V. The pyroelectric effect was significant due to the transparent and high photothermal PEDOT film, which could also work as an electrode. A hybrid energy harvester was assembled to enhance photoconversion efficiency (PCE) of a solar cell with a thermoelectric device operated by the photothermally generated heat. The PCE was increased more than 20% under sunlight irradiation (AM 1.5G) utilizing the transmitted light through the photovoltaic cell as a heat source that was converted into pyroelectric and thermoelectric output simultaneously from the high photothermal PEDOT electrodes. Overall, this work provides a dynamic and static hybrid energy cell to harvest solar energy in full spectral range and thermal energy, to allow solar powered switching of an electrochromic display.

  15. Co-Decaying Dark Matter

    OpenAIRE

    Dror, Jeff Asaf; Kuflik, Eric; Ng, Wee Hao

    2016-01-01

    We propose a new mechanism for thermal dark matter freezeout, termed Co-Decaying Dark Matter. Multi-component dark sectors with degenerate particles and out-of-equilibrium decays can co-decay to obtain the observed relic density. The dark matter density is exponentially depleted through the decay of nearly degenerate particles, rather than from Boltzmann suppression. The relic abundance is set by the dark matter annihilation cross-section, which is predicted to be boosted, and the decay rate ...

  16. Development of nuclear decay data library JDDL, and nuclear generation and decay calculation code COMRAD

    International Nuclear Information System (INIS)

    For safety evaluation of nuclear fuel facilities, a nuclear decay data library named JDDL and a computer code COMRAD have been developed to calculate isotopic composition of each nuclide, radiation source intensity, energy spectrum of γ-ray and neutron, and decay heat of spent fuel. JDDL has been produced mainly from the evaluated nuclear data file ENSDF to use new nuclear data. To supplement the data file for short life nuclides, the JNDC data set were also used which had been evaluated by Japan Nuclear Data Committee. Using these data, calculations became possible from short period to long period after irradiation. (author)

  17. Thermal stability of Zr55Al10Ni5Cu30 bulk amorphous alloy during continuous heating and isothermal annealing

    Institute of Scientific and Technical Information of China (English)

    高玉来; 沈军; 孙剑飞; 王刚; 邢大伟; 周彼德

    2003-01-01

    The crystallization behavior of Zr55Al10Ni5Cu30 (mole fraction, %) bulk amorphous alloy during continuous heating and isothermal annealing was investigated. The results show that there exists a first order exponential decay relation between the characteristic temperatures and the heating rates during continuous heating process. The activation energy for glass transition Eg and that for crystallization Ep and Ex during continuous heating were evaluated by Kissinger plots. In addition, there is a second order exponential decay relation between the annealing temperature and the corresponding crystallization time during isothermal annealing. The isothermal activation energy obtained by Arrhenius equation increases as crystallization proceeds, indicating the sufficient stability of the residual amorphous structure after initial crystallization.

  18. Supersymmetric top quark decays

    International Nuclear Information System (INIS)

    The supersymmetric decays of the top quark into charged Higgs plus bottom, t → H+b, and into the supersymmetric partner of the top (u1) plus the lightest neutralino (χ10), t → u1χ10, are discussed within the framework of the Minimal Supersymmetric Standard Model with radiatively induced breaking of the gauge group SU(2) x U(1). The possibility of detecting these decays at present, i.e. given the available bounds on supersymmetric parameters, is compared with the situation a Next e+e- Linear Collider would face if supersymmetric particles were still undiscovered at LEP II. The indirect implications for t → H+b and t → u1χ10 of a measurement of the bottom quark decay b → sγ at the Standard Model level are taken into account. (orig.)

  19. Suppressed Charmed B Decay

    Energy Technology Data Exchange (ETDEWEB)

    Snoek, Hella Leonie [Vrije Univ., Amsterdam (Netherlands)

    2009-06-02

    This thesis describes the measurement of the branching fractions of the suppressed charmed B0 → D*- a0+ decays and the non-resonant B0 → D*- ηπ+ decays in approximately 230 million Υ(4S) → B$\\bar{B}$ events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B0 → D*- a{sub 0}+ decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10-6. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle γ, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle γ can be performed using the decays of neutral B mesons. The B0 → D*- a0+ decay is sensitive to the angle γ and, in comparison to the current decays that are being employed, could significantly

  20. Antioxidant Enzymatic Activities and Gene Expression Associated with Heat Tolerance in the Stems and Roots of Two Cucurbit Species (“Cucurbita maxima” and “Cucurbita moschata”) and Their Interspecific Inbred Line “Maxchata”

    OpenAIRE

    Neelam Ara; Korakot Nakkanong; Wenhui Lv; Jinghua Yang; Zhongyuan Hu; Mingfang Zhang

    2013-01-01

    The elucidation of heat tolerance mechanisms is required to combat the challenges of global warming. This study aimed to determine the antioxidant enzyme responses to heat stress, at the enzymatic activity and gene expression levels, and to investigate the antioxidative alterations associated with heat tolerance in the stems and roots of squashes using three genotypes differing in heat tolerance. Plants of heat-tolerant “C. moschata”, thermolabile “C. maxima” and moderately heat-tolerant inte...

  1. Development of methods for activity determination for radionuclides with double decay emission β- β+ / electron capture - application to the standardization of 192Ir, 152Eu and 186 Re

    International Nuclear Information System (INIS)

    In the present work alternative procedures have been developed for standardization of radionuclides with double decay, β- β+ / electron capture using the 4πβ-γ coincidence technique, applying different systems. Two 4πβ-γ coincidence systems were used: one with a 4π gas-flow proportional counter coupled to a pair of NaI(Tl) scintillators and the other one with the same type of proportional counter coupled to HPGe detector. The radionuclides selected for this standardization, due to great interest in nuclear medicine, detector calibration and industrial radiography, were 192Ir, 152Eu and 186 Re. The first and the second were part of international comparisons sponsored by the Bureau International des Poids et Mesures (BIPM), France, who supplied the radioactive solution. For 186Re, the gamma-ray emission probability per decay was measured by means REGe spectrometer system, previously calibrated with standard ampoules. All the uncertainties involved were treated rigorously, by means of covariance analysis. (author)

  2. Double beta decay experiments

    International Nuclear Information System (INIS)

    The great sensitivity of double beta decay to neutrino mass and right handed currents has motivated many new and exciting attempts to observe this elusive nuclear phenomenon directly. Experiments in operation and other coming on line in the next one or two years are expected to result in order-of-magnitude improvements in detectable half lives for both the two-neutrino and no-neutrino modes. A brief history of double beta decay experiments is presented together with a discussion of current experimental efforts, including a gas filled time projection chamber being used to study selenium-82. (author)

  3. Fast Proton Decay

    OpenAIRE

    Li, Tianjun; Nanopoulos, Dimitri V.; Walker, Joel W.

    2009-01-01

    We consider proton decay in the testable flipped SU(5) X U(1)_X models with TeV-scale vector-like particles which can be realized in free fermionic string constructions and F-theory model building. We significantly improve upon the determination of light threshold effects from prior studies, and perform a fresh calculation of the second loop for the process p \\to e^+ \\pi^0 from the heavy gauge boson exchange. The cumulative result is comparatively fast proton decay, with a majority of the mos...

  4. CORONAL HEATING BY THE INTERACTION BETWEEN EMERGING ACTIVE REGIONS AND THE QUIET SUN OBSERVED BY THE SOLAR DYNAMICS OBSERVATORY

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jun; Zhang, Bin; Li, Ting; Yang, Shuhong; Zhang, Yuzong; Li, Leping [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Chen, Feng; Peter, Hardi, E-mail: zjun@nao.cas.cn, E-mail: liting@nao.cas.cn, E-mail: shuhongyang@nao.cas.cn, E-mail: yuzong@nao.cas.cn, E-mail: lepingli@nao.cas.cn, E-mail: chen@mps.mpg.de, E-mail: peter@mps.mpg.de [Max-Planck Institute for Solar System Research (MPS), D-37077, Göttingen (Germany)

    2015-02-01

    The question of what heats the solar corona remains one of the most important puzzles in solar physics and astrophysics. Here we report Solar Dynamics Observatory Atmospheric Imaging Assembly observations of coronal heating by the interaction between emerging active regions (EARs) and the surrounding quiet Sun (QS). The EARs continuously interact with the surrounding QS, resulting in dark ribbons which appear at the boundary of the EARs and the QS. The dark ribbons visible in extreme-ultraviolet wavelengths propagate away from the EARs with speeds of a few km s{sup −1}. The regions swept by the dark ribbons are brightening afterward, with the mean temperature increasing by one quarter. The observational findings demonstrate that uninterrupted magnetic reconnection between EARs and the QS occurs. When the EARs develop, the reconnection continues. The dark ribbons may be the track of the interface between the reconnected magnetic fields and the undisturbed QS’s fields. The propagating speed of the dark ribbons reflects the reconnection rate and is consistent with our numerical simulation. A long-term coronal heating which occurs in turn from nearby the EARs to far away from the EARs is proposed.

  5. Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores. II. Nanoflare Trains

    CERN Document Server

    Barnes, W T; Bradshaw, S J

    2016-01-01

    Despite its prediction over two decades ago, the detection of faint, high-temperature ("hot") emission due to nanoflare heating in non-flaring active region cores has proved challenging. Using an efficient two-fluid hydrodynamic model, this paper investigates the properties of the emission expected from repeating nanoflares (a nanoflare train) of varying frequency as well as the separate heating of electrons and ions. If the emission measure distribution ($\\mathrm{EM}(T)$) peaks at $T = T_m$, we find that $\\mathrm{EM}(T_m)$ is independent of details of the nanoflare train, and $\\mathrm{EM}(T)$ above and below $T_m$ reflects different aspects of the heating. Below $T_m$ the main influence is the relationship of the waiting time between successive nanoflares to the nanoflare energy. Above $T_m$ power-law nanoflare distributions lead to an extensive plasma population not present in a monoenergetic train. Furthermore, in some cases characteristic features are present in $\\mathrm{EM}(T)$. Such details may be detec...

  6. CORONAL HEATING BY THE INTERACTION BETWEEN EMERGING ACTIVE REGIONS AND THE QUIET SUN OBSERVED BY THE SOLAR DYNAMICS OBSERVATORY

    International Nuclear Information System (INIS)

    The question of what heats the solar corona remains one of the most important puzzles in solar physics and astrophysics. Here we report Solar Dynamics Observatory Atmospheric Imaging Assembly observations of coronal heating by the interaction between emerging active regions (EARs) and the surrounding quiet Sun (QS). The EARs continuously interact with the surrounding QS, resulting in dark ribbons which appear at the boundary of the EARs and the QS. The dark ribbons visible in extreme-ultraviolet wavelengths propagate away from the EARs with speeds of a few km s−1. The regions swept by the dark ribbons are brightening afterward, with the mean temperature increasing by one quarter. The observational findings demonstrate that uninterrupted magnetic reconnection between EARs and the QS occurs. When the EARs develop, the reconnection continues. The dark ribbons may be the track of the interface between the reconnected magnetic fields and the undisturbed QS’s fields. The propagating speed of the dark ribbons reflects the reconnection rate and is consistent with our numerical simulation. A long-term coronal heating which occurs in turn from nearby the EARs to far away from the EARs is proposed

  7. Influence of water activity and temperature on survival of and colony formation by heat-stressed Chrysosporium farinicola aleuriospores.

    OpenAIRE

    Beuchat, L R; Pitt, J. I.

    1990-01-01

    The ability of sublethally heat-stressed aleuriospores of Chrysosporium farinicola to form colonies on yeast extract-glucose agar (YGA) supplemented with sufficient glucose, sorbitol, glycerol, and NaCl to achieve reduced water activity (aw) in the range of 0.88 to 0.95 was determined. The effects of the aw of diluent and incubation temperature during recovery and colony formation were also investigated. Aleuriospores harvested from 14-day-old cultures grown at 25 degrees C were less resistan...

  8. Effects of PEF and heat pasteurization on PME activity in orange juice with regard to a new inactivation kinetic model.

    Science.gov (United States)

    Agcam, E; Akyıldız, A; Evrendilek, G Akdemir

    2014-12-15

    The inactivation kinetics of pectin methyl esterase (PME) during the shelf life (4°C-180 days) of freshly squeezed orange juice samples processed by both pulsed electric fields (PEF) and heat pasteurization (HP) was evaluated in the study. The PME inactivation level after the PEF (25.26 kV/cm-1206.2 μs) and HP (90°C-20s) treatments were 93.8% and 95.2%, respectively. The PME activity of PEF-processed samples decreased or did not change, while that of HP samples increased during storage (porange juice during storage.

  9. Influence of water activity and temperature on survival of and colony formation by heat-stressed Chrysosporium farinicola aleuriospores.

    Science.gov (United States)

    Beuchat, L R; Pitt, J I

    1990-10-01

    The ability of sublethally heat-stressed aleuriospores of Chrysosporium farinicola to form colonies on yeast extract-glucose agar (YGA) supplemented with sufficient glucose, sorbitol, glycerol, and NaCl to achieve reduced water activity (aw) in the range of 0.88 to 0.95 was determined. The effects of the aw of diluent and incubation temperature during recovery and colony formation were also investigated. Aleuriospores harvested from 14-day-old cultures grown at 25 degrees C were less resistant to heat inactivation compared with aleuriospores from 20-day-cultures. Increased populations of heat-stressed aleuriospores were recovered as the aw of YGA was decreased from 0.95 (glucose and glycerol) and 0.94 (sorbitol) to 0.89 and 0.88, respectively. In NaCl-supplemented YGA, populations recovered at an aw of 0.94 were greatly reduced compared with populations detected at an aw of 0.92; no colonies were formed on NaCl-supplemented YGA at an aw of 0.88. Tolerance to aw values above 0.88 to 0.89 as influenced by solute type was in the order of glucose greater than sorbitol greater than glycerol greater than NaCl. Incubation at 20 degrees generally resulted in an increase in recoverable aleuriospores compared with incubation at 25 degrees C or at 30 degrees C for 14 days followed by 20 degrees C for 10 days. The lethal effect of NaCl on heat-stressed aleuriospores was enhanced at 30 degrees C. The retention of viability of aleuriospores held in sucrose-peptone water diluent (aw, 0.936) for 20 min was essentially the same as that observed when aleuriospores were held in peptone water (aw, 0.997).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2285307

  10. Absence of arterial baroreflex modulation of skin sympathetic activity and sweat rate during whole-body heating in humans

    Science.gov (United States)

    Wilson, T. E.; Cui, J.; Crandall, C. G.

    2001-01-01

    1. Prior findings suggest that baroreflexes are capable of modulating skin blood flow, but the effects of baroreceptor loading/unloading on sweating are less clear. Therefore, this project tested the hypothesis that pharmacologically induced alterations in arterial blood pressure in heated humans would lead to baroreflex-mediated changes in both skin sympathetic nerve activity (SSNA) and sweat rate. 2. In seven subjects mean arterial blood pressure was lowered (approximately 8 mmHg) and then raised (approximately 13 mmHg) by bolus injections of sodium nitroprusside and phenylephrine, respectively. Moreover, in a separate protocol, arterial blood pressure was reduced via steady-state administration of sodium nitroprusside. In both normothermia and heat-stress conditions the following responses were monitored: sublingual and mean skin temperatures, heart rate, beat-by-beat blood pressure, skin blood flow (laser-Doppler flowmetry), local sweat rate and SSNA (microneurography from peroneal nerve). 3. Whole-body heating increased skin and sublingual temperatures, heart rate, cutaneous blood flow, sweat rate and SSNA, but did not change arterial blood pressure. Heart rate was significantly elevated (from 74 +/- 3 to 92 +/- 4 beats x min(-1); P < 0.001) during bolus sodium nitroprusside-induced reductions in blood pressure, and significantly reduced (from 92 +/- 4 to 68 +/- 4 beats x min(-1); P < 0.001) during bolus phenylephrine-induced elevations in blood pressure, thereby demonstrating normal baroreflex function in these subjects. 4. Neither SSNA nor sweat rate was altered by rapid (bolus infusion) or sustained (steady-state infusion) changes in blood pressure regardless of the thermal condition. 5. These data suggest that SSNA and sweat rate are not modulated by arterial baroreflexes in normothermic or moderately heated individuals.

  11. Baryogenesis and proton decay

    International Nuclear Information System (INIS)

    The constraints are analyzed that proton decay experiments and cosmologically sound unification models impose on each other. An intermediate scale of around 1010 GeV arises from considerations on baryogenesis, inflation and supersymmetry breaking. An upper bound to the gravitino mass of about 50 TeV follows from current proton lifetime limits

  12. Hyperon Radiative Decay

    OpenAIRE

    Kaxiras, Efthimios; Soyeur, Madeleine; Moniz, Ernest J.

    1985-01-01

    The radiative decay widths of the low-lying strange baryons are calculated both within the relativistic quark bag model and the nonrelativistic potential model. These widths are found to depend sensitively upon the quark-model dynamics through multiplet mixing and q4¯q admixtures. The comparison between our calculated results and the very limited experimental data is discussed.

  13. Neutrinoless τ decays

    International Nuclear Information System (INIS)

    Lepton number and lepton flavor violation processes occur naturally in many extensions of the Standard Model. No evidence for such processes has been found so far. Recent searches for lepton number violating τ decays are reviewed within the context of the theoretical predictions

  14. Neutrinoless Double Beta Decay

    CERN Document Server

    Päs, Heinrich

    2015-01-01

    We review the potential to probe new physics with neutrinoless double beta decay $(A,Z) \\to (A,Z+2) + 2 e^-$. Both the standard long-range light neutrino mechanism as well as short-range mechanisms mediated by heavy particles are discussed. We also stress aspects of the connection to lepton number violation at colliders and the implications for baryogenesis.

  15. Attention decay in science

    CERN Document Server

    Parolo, Pietro Della Briotta; Ghosh, Rumi; Huberman, Bernardo A; Kaski, Kimmo; Fortunato, Santo

    2015-01-01

    The exponential growth in the number of scientific papers makes it increasingly difficult for researchers to keep track of all the publications relevant to their work. Consequently, the attention that can be devoted to individual papers, measured by their citation counts, is bound to decay rapidly. In this work we make a thorough study of the life-cycle of papers in different disciplines. Typically, the citation rate of a paper increases up to a few years after its publication, reaches a peak and then decreases rapidly. This decay can be described by an exponential or a power law behavior, as in ultradiffusive processes, with exponential fitting better than power law for the majority of cases. The decay is also becoming faster over the years, signaling that nowadays papers are forgotten more quickly. However, when time is counted in terms of the number of published papers, the rate of decay of citations is fairly independent of the period considered. This indicates that the attention of scholars depends on th...

  16. A scintillating bolometer array for double beta decay studies: The LUCIFER experiment

    Science.gov (United States)

    Gironi, L.

    2016-07-01

    The main goal of the LUCIFER experiment is to study the neutrinoless double beta decay, a rare process allowed if neutrinos are Majorana particles. Although aiming at a discovery, in the case of insufficient sensitivity the LUCIFER technique will be the demonstrator for a higher mass experiment able to probe the entire inverted hierarchy region of the neutrino mass. In order to achieve this challenging result, high resolution detectors with active background discrimination capability are required. This very interesting possibility can be largely fulfilled by scintillating bolometers thanks to the simultaneous read-out of heat and light emitted by the interactions in the detector or by pulse shape analysis.

  17. Topoisomerase activity during the heat shock response in Escherichia coli K-12.

    Science.gov (United States)

    Camacho-Carranza, R; Membrillo-Hernández, J; Ramírez-Santos, J; Castro-Dorantes, J; Chagoya de Sánchez, V; Gómez-Eichelmann, M C

    1995-01-01

    During the upshift of temperature from 30 to 42, 45, 47, or 50 degrees C, an increase in the level of supercoiling of a reporter plasmid was observed. This increase was present in groE and dnaK mutants but was inhibited in cells treated with chloramphenicol and novobiocin. The intracellular [ATP]/[ADP] ratio increased rapidly after an upshift in temperature from 30 to 47 degrees C and then decreased to reach a level above that observed at 30 degrees C. These results suggest that gyrase and proteins synthesized during heat shock are responsible for the changes seen in plasmid supercoiling. Proteins GroE and DnaK are probably not involved in this phenomenon. PMID:7768879

  18. Modeling the heat and mass transfers in temperature-swing adsorption of volatile organic compounds onto activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Sylvain Giraudet; Pascaline Pre; Pierre Le Cloirec [Ecole des Mines de Nantes, Nantes (France)

    2009-02-15

    A theoretical model was built to simulate the adsorption of volatile organic compounds (VOCs) onto activated carbons in a fixed bed. This model was validated on a set of experimental data obtained for the adsorption of acetone, ethyl formate, and dichloromethane onto five commercial activated carbons. The influence of operating conditions was modeled with various VOC contents at the inlet of the adsorber and superficial velocities of the gas-phase from 0.14 to 0.28 m.s{sup -1}. Breakthrough times and maximum temperature rises were computed with a coefficient of determination of 0.988 and 0.901, respectively. The simulation was then extended to the adsorption of mixtures of VOCs. From the comparison of simulation and experimental results, the advantage of accounting for dispersions of heat and mass is shown and the importance in taking into account the temperature effect on the equilibrium data is demonstrated. 29 refs., 6 figs., 1 tab.

  19. Generating bifunctional fusion enzymes composed of heat-active endoglucanase (Cel5A) and endoxylanase (XylT).

    Science.gov (United States)

    Rizk, Mazen; Elleuche, Skander; Antranikian, Garabed

    2015-01-01

    Bifunctional enzyme constructs were generated comprising two genes encoding heat-active endoglucanase (cel5A) and endoxylanase (xylT). The fused proteins Cel5A-XylT and XylT-Cel5A were active on both β-glucan and beechwood xylan. An improvement in endoglucanase and endoxylanase catalytic activities was observed. The specific activity of the fusion towards xylan was significantly raised when compared to XylT. The fusion constructs were active from 40 to 100 °C for endoglucanase and from 40 to 90 °C for endoxylanase, but the temperature optima were lowered from 90 to 80 °C for the endoglucanase and from 80 to 70 °C for the endoxylanase. XylT in the construct XylT-Cel5A was less stable at higher temperatures compared to Cel5A-XylT. Due to the enzymatic performance, these fusion enzymes are attractive candidates for applications in biorefineries based on plant waste.

  20. Heat-Powered Pump for Liquid Metals

    Science.gov (United States)

    Campana, R. J.

    1986-01-01

    Proposed thermoelectromagnetic pump for liquid metal powered by waste heat; needs no battery, generator, or other external energy source. Pump turns part of heat in liquid metal into pumping energy. In combination with primary pump or on its own, thermoelectric pump circulates coolant between reactor and radiator. As long as there is decay heat to be removed, unit performs function.

  1. Rare B decays at LEP

    CERN Document Server

    Kluit, P M

    2001-01-01

    The results of the LEP experiments for rare B decays will be reviewed, covering hadronic final states, radiative and other rare decays and results for the inclusive charmless branching ratio. (8 refs).

  2. CP-violations in decays

    Indian Academy of Sciences (India)

    Y Sakai

    2006-11-01

    Recent results on CP-violation measurements in decays from energy asymmetric -factory experiments are reported. Thanks to large accumulated data samples, CP-violations in decays in mixing-decay interference and direct CP-violation are now firmly established. The measurements of three angles of the unitarity triangle from CP-violations of decays are quite consistent with the Standard Model expectations. These results strongly support the validity of the Kobayashi-Maskawa prescription of CP-violation.

  3. Rare Down Quark Decays

    Science.gov (United States)

    Tung, Kwong-Kwai Humphrey

    1992-01-01

    The rare decays bto sX are sensitive to strong interaction corrections. The effects can be estimated by a renormalization group technique which requires the evaluation of QCD mixing among effective operators. In the dimensional reduction and the naive dimensional regularization methods, there are discrepancies in evaluating the QCD mixing of the four-quark operators with the bto sgamma and bto s+gluon dipole operators. In this thesis, the problem is investigated by considering the contributions of the epsilon -scalar field and the epsilon -dimensional operators that distinguish between the two methods. The discrepancies are shown to come from the epsilon-dimensional four-quark operators in dimensional reduction and not from the epsilon -scalar field. In the decay bto sl^+l^ -, the intermediate of cc pairs in the charm-penguin diagram can form the resonance states J/psi and psi^'. In the published literature, there is a sign discrepancy in the Breit-Wigner amplitude for the resonance effects. Here, the sign difference is settled by considering the unitarity limit of the amplitude in the Argand diagram. The effects of the resonances are quite substantial on the invariant mass spectrum for this decay. However, they are shown to be negligible on the dilepton energy spectrum below 0.95 GeV. The energy spectrum is, thus, more useful than the invariant mass spectrum for measurements of the top -quark mass. The decays Bto K^*X are well modeled by the quark-level decays bto sX. In the quark model, the hadronization is done using a nonrelativistic wave function. In the decay B to K^*gamma, the large K ^* recoil creates an uncertainty in calculating the branching ratio using the quark model. The problem is explored by considering other meson processes where data exist. The data on the pi form factor and the omegapi^0 transition form factor suggest the necessity to retain relativistic spinor and meson normalizations in the quark -model; however, the data do not resolve the

  4. Semiconductor detectors and double beta decay

    International Nuclear Information System (INIS)

    The underlying theory of double beta decay is discussed as well as some experimental observations. A class of second generation 76Ge detector experiments is then discussed. The design and physics considerations involved in the system used by LBL are explained, particularly the means of rejecting background activity. 24 references, 18 figures, 3 tables

  5. Decay of charge deposited on the wall of gaseous void

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    1992-01-01

    After partial discharge activity within a gaseous void, charges accumulate on the wall of the void. The decay of such charges due to surface currents at the void wall is studied analytically, and the factors affecting this decay are indicated. The results show that in terms of the basic time...

  6. Recent activities for β-decay half-lives and β-delayed neutron emission of very neutron-rich isotopes

    International Nuclear Information System (INIS)

    Beta-delayed neutron (βn) emitters play an important, two-fold role in the stellar nucleosynthesis of heavy elements in the 'rapid neutron-capture process' (r process). On one hand they lead to a detour of the material β-decaying back to stability. On the other hand, the released neutrons increase the neutron-to-seed ratio, and are re-captured during the freeze-out phase and thus influence the final solar r-abundance curve. A large fraction of the isotopes inside the r-process reaction path are not yet experimentally accessible and are located in the (experimental) 'Terra Incognita'. With the next generation of fragmentation and ISOL facilities presently being built or already in operation, one of the main motivation of all projects is the investigation of these very neutron-rich isotopes. A short overview of one of the planned programs to measure βn-emitters at the limits of the presently know isotopes, the BRIKEN campaign (Beta delayed neutron emission measurements at RIKEN) will be given. Presently, about 600 β-delayed one-neutron emitters are accessible, but only for a third of them experimental data are available. Reaching more neutron-rich isotopes means also that multiple neutron-emission becomes the dominant decay mechanism. About 460 β-delayed two-, three-or four-neutron emitters are identified up to now but for only 30 of them experimental data about the neutron branching ratios are available, most of them in the light mass region below A=30. The International Atomic and Energy Agency (IAEA) has identified the urgency and picked up this topic recently in a 'Coordinated Research Project' on a 'Reference Database for Beta-Delayed Neutron Emission Data'. This project will review, compile, and evaluate the existing data for neutron-branching ratios and half-lives of β-delayed neutron emitters and help to ensure a reliable database for the future discoveries of new isotopes and help to constrain astrophysical and theoretical models

  7. Antimatter signatures of gravitino dark matter decay

    International Nuclear Information System (INIS)

    The scenario of gravitino dark matter with broken R-parity naturally reconciles three paradigms that, albeit very well motivated separately, seem to be in mutual conflict: supersymmetric dark matter, thermal leptogenesis and standard big bang nucleosynthesis. Interestingly, the products of the gravitino decay could be observed, opening the possibility of indirect detection of gravitino dark matter. In this paper, we compute the positron and the antiproton fluxes from gravitino decay. We find that a gravitino with a mass of m3/2∼150 GeV and a lifetime of τ3/2∼1026 s could simultaneously explain the EGRET anomaly in the extragalactic diffuse gamma ray background and the HEAT excess in the positron fraction. However, the predicted antiproton flux tends to be too large, although the prediction suffers from large uncertainties and might be compatible with present observations for certain choices of propagation parameters

  8. Electroweak penguin B decays

    CERN Document Server

    Nikodem, Thomas

    2016-01-01

    Flavour Changing Neutral Currents (FCNC) are sensitive probes for physics beyond the Standard Model (SM), so-called New Physics. An example of a FCNC is the $b \\to s$ quark transition described by the electroweak penguin Feynman diagram shown in Figure 1. In the SM such FCNC are only allowed with a loop structure (as e:g: shown in the figure) and not by tree level processes. In the loops heavy particles appear virtually and do not need to be on shell. Therefore also not yet discovered heavy particles with up to a mass $\\mathcal{O}$(TeV) could virtually contribute significantly to observables. Several recent measurements of electroweak penguin B decays exhibit interesting tensions with SM predictions, most prominently in the angular observable $P'_5$ 5 of the decay $B^0 \\to K^{*0} \\mu^+ \\mu^1$[1], which triggered a lot of discussion in the theory community [2]-[14].

  9. Rare b decays

    Energy Technology Data Exchange (ETDEWEB)

    Tung, K.K.H.

    1992-01-01

    The rare decays b [yields] sX are sensitive to strong interaction corrections. The effects can be estimated by a renormalization group technique which requires the evaluation of QCD mixing among effective operators. In the dimensional reduction and the naive dimensional regularization methods, there are discrepancies in evaluating the QCD mixing of the four-quark operators with the b [yields] s[gamma] and b [yields] s + gluon dipole operators. The problem is investigated by considering the contributions of the [epsilon]-scalar field and the [epsilon]-dimensional operators that distinguish between the methods. The discrepancies come from the [epsilon]-dimensional four-quark operators in dimensional reduction. In the decay b [yields] sl[sup +]l[sup [minus

  10. Activation analysis for different structural alloys considered for ITER

    International Nuclear Information System (INIS)

    Activation calculations have been made for the austentic steel 316SS, the ferritic alloy HT-9, the titanium alloy Ti6A14V, and the vanadium alloy V5Cr5Ti in a liquid metal (Na) design suggested recently for ITER. The calculations show that the vanadium alloy has the minimum short and long-term radioactivity and BHP. It also has the minimum decay heat at all the time. The titanium alloy has less radioactivity than the austenitic and this ferritic alloys. However, the decay heat of this alloy could exceed that of the conventional alloys

  11. Effect of Heat Input on Microstructure Evolution and Mechanical Properties in the Weld Heat-Affected Zone of 9Cr-2W-VTa Reduced Activation Ferritic-Martensitic Steel for Fusion Reactor

    Science.gov (United States)

    Moon, Joonoh; Lee, Chang-Hoon; Lee, Tae-Ho; Kim, Hyoung Chan

    2015-01-01

    The phase transformation and mechanical properties in the weld heat-affected zone (HAZ) of a reduced activation ferritic/martensitic steel were explored. The samples for HAZs were prepared using a Gleeble simulator at different heat inputs. The base steel consisted of tempered martensite and carbides through quenching and tempering treatment, whereas the HAZs consisted of martensite, δ-ferrite, and a small volume of autotempered martensite. The prior austenite grain size, lath width of martensite, and δ-ferrite fraction in the HAZs increased with increase in the heat input. The mechanical properties were evaluated using Vickers hardness and Charpy V-notch impact test. The Vickers hardness in the HAZs was higher than that in the base steel but did not change noticeably with increase in the heat input. The HAZs showed poor impact property due to the formation of martensite and δ-ferrite as compared to the base steel. In addition, the impact property of the HAZs deteriorated more with the increase in the heat input. Post weld heat treatment contributed to improve the impact property of the HAZs through the formation of tempered martensite, but the impact property of the HAZs remained lower than that of base steel.

  12. Beta decay for pedestrians

    CERN Document Server

    Lipkin, Harry Jeannot

    1962-01-01

    The ""pedestrian approach"" was developed to describe some essentially simple experimental results and their theoretical implications in plain language. In this graduate-level text, Harry J. Lipkin presents simply, but without oversimplification, the aspects of beta decay that can be understood without reference to the formal theory; that is, the reactions that follow directly from conservation laws and elementary quantum mechanics.The pedestrian treatment is neither a substitute for a complete treatment nor a watered-down version.

  13. Bremsstrahlung in $\\alpha$ Decay

    CERN Document Server

    Takigawa, N; Hagino, K; Ono, A; Brink, D M

    1999-01-01

    A quantum mechanical analysis of the bremsstrahlung in $\\alpha$ decay of $^{210}$Po is performed in close reference to a semiclassical theory. We clarify the contribution from the tunneling, mixed, outside barrier regions and from the wall of the inner potential well to the final spectral distribution, and discuss their interplay. We also comment on the validity of semiclassical calculations, and the possibility to eliminate the ambiguity in the nuclear potential between the alpha particle and daughter nucleus using the bremsstrahlung spectrum.

  14. Teleportation via decay

    Indian Academy of Sciences (India)

    S Bose; P L Knight; M B Plenio; V Vedral

    2001-02-01

    We present a rare example of a decay mechanism playing a constructive role in quantum information processing. We show how the state of an atom trapped in a cavity can be teleported to a second atom trapped in a distant cavity by the joint detection of photon leakage from the cavities. The scheme, which is probabilistic, requires only a single three level atom in a cavity. We also show how this scheme can be modified to a teleportation with insurance.

  15. Decay of Polarized Delta

    OpenAIRE

    Ramachandran, G.; Venkataraya; Vidya, M. S.; Balasubramanyam, J.; Padmanabha, G.

    2009-01-01

    The resonance $\\Delta(1232)$ with spin-parity ${3 \\over 2}^+$, which contributes dominantly to the reactions like $\\gamma N \\to \\pi N$ and $NN \\to NN\\pi$ at intermediate energies, may be expected to be produced in characteristically different polarized spin states. As such an analysis of the decay of polarized delta is presented, which may be utilized to probe empirically the production mechanism. It is shown that measurements of the angular distributions of the pion and the polarization of t...

  16. Rare D Decays

    CERN Document Server

    Casey, Brendan

    2007-01-01

    We discuss several recent measurements of rare charmed hadron decays. Focus is placed on radiative and annihilation topologies highlighting their sensitivity to new physics and pointing out the strengths and weaknesses of different channels. We compare the different measurement techniques employed at fixed target and $e^+e^-$ dedicated charm experiments, B-factories, and the Tevatron experiments. Comparisons are also made to similar topologies in the beauty, strange, and top systems where appropriate.

  17. Charmless B decays

    Directory of Open Access Journals (Sweden)

    Martens Aurélien

    2014-04-01

    Full Text Available During 2011, LHCb has collected an integrated luminosity of 1.1 fb−1, giving rise to a large variety of measurements. Amongst these, measurements of CP violation in B decays play a central role. In particular CP violation measurements in charmless transitions of B mesons are of interest since they provide new or improved constraints on new physics contributions. These proceedings concentrate on LHCb results made publicin the first half of the year 2012.

  18. State opportunities for action: Update of states' combined heat and power activities

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Elizabeth [American Council for an Energy-Efficient Economy, Washington, D.C. (United States); Elliott, R. Neal [American Council for an Energy-Efficient Economy, Washington, D.C. (United States)

    2003-10-01

    This report updates the review of state policies with regard to CHP that the American Council for and Energy Efficient Economy completed in 2002. It describes the current activities of states with programs during the initial survey and also reviews new programs offered by the states.

  19. On the estimation of heating effects in the atmosphere because of seismic activities

    Science.gov (United States)

    Meister, Claudia-Veronika; Hoffmann, Dieter H. H.

    2014-05-01

    The dielectric model for waves in the Earth's ionosphere is further developed and applied to possible electro-magnetic phenomena in seismic regions. In doing so, in comparison to the well-known dielectric wave model by R.O. Dendy [Plasma dynamics, Oxford University Press, 1990] for homogeneous systems, the stratification of the atmosphere is taken into account. Moreover, within the frame of many-fluid magnetohydrodynamics also the momentum transfer between the charged and neutral particles is considered. Discussed are the excitation of Alfvén and magnetoacoustic waves, but also their variations by the neutral gas winds. Further, also other current driven waves like Farley-Buneman ones are studied. In the work, models of the altitudinal scales of the plasma parameters and the electromagnetic wave field are derived. In case of the electric wave field, a method is given to calculate the altitudinal scale based on the Poisson equation for the electric field and the magnetohydrodynamic description of the particles. Further, expressions are derived to estimate density, pressure, and temperatur changes in the E-layer because of the generation of the electromagnetic waves. Last not least, formulas are obtained to determine the dispersion and polarisation of the excited electromagnetic waves. These are applied to find quantitative results for the turbulent heating of the ionospheric E-layer. Concerning the calculation of the dispersion relation, in comparison to a former work by Meister et al. [Contr. Plasma Phys. 53 (4-5), 406-413, 2013], where a numerical double-iteration method was suggested to obtain results for the wave dispersion relations, now further analytical calculations are performed. In doing so, different polynomial dependencies of the wave frequencies from the wave vectors are treated. This helped to restrict the numerical calculations to only one iteration process.

  20. Influence of mass recovery on the performance of a heat pipe type ammonia sorption refrigeration system using CaCl2/activated carbon as compound adsorbent

    International Nuclear Information System (INIS)

    The performance analyses of a sorption refrigeration system with different mass recovery processes are presented, in which compound adsorbent of CaCl2 and activated carbon is used to improve the mass and heat transfer performances of sorption bed. The heating, cooling and heat recovery processes between two sorption beds were performed by multifunction heat pipes without additional power consumption. The experimental Clapeyron diagrams showed that the cycles with mass recovery (MR), with heat and mass recoveries (HMR), and with mass and heat recoveries (MHR), have better thermodynamic performances when compared with the sorption cycle without mass recovery (MR0). The implementary order of mass recovery and heat recovery has strong influence on the efficacy of mass recovery while it has little influence on the efficacy of heat recovery. In sorption cycles with HMR and with MHR, the hot beds can be pre-cooled and cold beds can be pre-heated effectively during the switching process, and heat consumption from external heat source during desorption phase is thereby reduced. Mass recovery can enlarge cycled refrigerant mass due to the transfer of refrigerant gas between two sorption beds during mass recovery process. In comparison with sorption cycle with MR0, sorption cycles with MR, with HMR, and with MHR can generally improve the coefficient of performance (COP) and specific cooling power (SCP) by more than 20% and 16%, respectively. Especially, sorption cycle with MHR has the highest performance among different mass recovery processes due to the fact that MHR has the advantages of MR and HMR, and it can improve the COP by 46.7% when compared with the cycle with MR0