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Sample records for repassivation potential temperature

  1. Effect of Nitrate on the Repassivation Potential of Alloy 22 in Chloride Containing Environment

    Energy Technology Data Exchange (ETDEWEB)

    G. Ilevbare; K. King; S. Gordon; H. Elayat; G. Gdowski; T. Summers

    2004-09-21

    The study of Alloy 22 was undertaken in several selected nitrate/chloride (NO{sub 3}{sup -}/Cl{sup -}) electrolytes with chloride concentrations [Cl{sup -}] of 1.0, 3.5 and 6.0 molal with [NO{sub 3}{sup -}]/[Cl{sup -}] ratios of 0.05, 0.15 and 0.5 at temperatures up to 100 C. The repassivation potentials increased with increase in [NO{sub 3}{sup -}]/[Cl{sup -}] ratio and decreased with increase in temperature. The absolute [Cl{sup -}] was found to have less of an effect on the repassivation potential compared with temperature and the [NO{sub 3}{sup -}]/[Cl{sup -}]. Regression analyses were carried out to describe the relationship between the repassivation potential, temperature, [Cl{sup -}] and [NO{sub 3}{sup -}] for the conditions tested.

  2. Effect of Nitrate on the Repassivation Potential of Alloy 22 in Chloride Containing Environment

    Energy Technology Data Exchange (ETDEWEB)

    G. Ilevbare; K. King; S. Gordon; H. Elayat; G. Gdowski; T. Summers

    2004-09-21

    The study of Alloy 22 was undertaken in several selected nitrate/chloride (NO{sub 3}{sup -}/Cl{sup -}) electrolytes with chloride concentrations [Cl{sup -}] of 1.0, 3.5 and 6.0 molal with [NO{sub 3}{sup -}]/[Cl{sup -}] ratios of 0.05, 0.15 and 0.5 at temperatures up to 100 C. The repassivation potentials increased with increase in [NO{sub 3}{sup -}]/[Cl{sup -}] ratio and decreased with increase in temperature. The absolute [Cl{sup -}] was found to have less of an effect on the repassivation potential compared with temperature and the [NO{sub 3}{sup -}]/[Cl{sup -}]. Regression analyses were carried out to describe the relationship between the repassivation potential, temperature, [Cl{sup -}] and [NO{sub 3}{sup -}] for the conditions tested.

  3. EFFECT OF NITRATE ON THE REPASSIVATION POTENTIAL OF ALLOY 22 IN CHLORIDE CONTAINING ENVIRONMENTS.

    Energy Technology Data Exchange (ETDEWEB)

    Ilevbare, G; King, K; Gordon, S; Elayat, H; Gdowski, G; Summers, T

    2004-08-16

    The study of Alloy 22 was undertaken in several selected nitrate/chloride (NO{sub 3}{sup -}/Cl{sup -}) electrolytes with chloride concentrations [Cl{sup -}] of 1.0, 3.5 and 6.0 molal with [NO{sub 3} {sup -}]/[Cl{sup -}] ratios of 0.05, 0.15 and 0.5 at temperatures up to 100 C. Results showed that the repassivation potentials increased with increase in [NO{sub 3} {sup -}]/[Cl{sup -}] ratio and decreased with increase in temperature. The absolute [Cl{sup -}] was found to have less of an effect on the repassivation potential compared with temperature and the NO{sub 3} {sup -}/Cl{sup -}. Regression analyses were carried out and expressions were derived to describe the relationship between the repassivation potential, temperature, [Cl{sup -}] and [NO{sub 3} {sup -}] for the conditions tested.

  4. The Effect of Temperature on the Breakdown and Repassivation Potentials of Welded Alloy 22 In 5 M CACI2

    Energy Technology Data Exchange (ETDEWEB)

    G.O. IIevbare

    2006-07-05

    The study of the electrochemical behavior of wrought and welded Alloy 22 was carried out in 5 M CaCl{sub 2} as a function of temperatures between 45 and 120 C with Multiple Crevice Assembly (MCA) specimens. The susceptibility to corrosion was found to increase with increase in electrolyte temperature in both the wrought (in the mill annealed condition) and the welded forms of the alloy. The weld metal was found to be less susceptible to localized corrosion under the conditions tested.

  5. Measuring the Repassivation Potential of Alloy 22 Using the Potentiodynamic - Galvanostatic - Potentiostatic Method

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    Evans, K J; Rebak, R B

    2007-04-27

    Traditionally, the susceptibility of Alloy 22 (N06022) to suffer crevice corrosion has been measured using the Cyclic Potentiodynamic Polarization (CPP) technique (ASTM G 61). When the alloy is not very susceptible to crevice corrosion, the values of repassivation potential obtained using the CPP technique are not highly reproducible. To circumvent the large uncertainty in the values of the repassivation potential by the CPP method, the repassivation potential of Alloy 22 may be measured using a slower method that combines sequentially potentiodynamic, galvanostatic and potentiostatic treatments (this method is called the Tsujikawa-Hisamatsu Electrochemical or THE method). In the THE method the anodic charge is applied to the specimen in a more controlled manner, which avoids driving the alloy to transpassivity and therefore results in more reproducible repassivation potential values. Results using THE method under various testing conditions are presented. A new standard has been prepared for ASTM balloting for the THE method. The round robin matrix results are also discussed.

  6. Repassivation Potential of Alloy 22 in Sodium and Calcium Chloride Brines

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B; Ilevbare, G O; Carranza, R M

    2007-08-11

    A comprehensive matrix of 60 tests was designed to explore the effect of calcium chloride vs. sodium chloride and the ratio R of nitrate concentration over chloride concentration on the repassivation potential of Alloy 22. Tests were conducted using the cyclic potentiodynamic polarization (CPP) technique at 75 C and at 90 C. Results show that at a ratio R of 0.18 and higher nitrate was able to inhibit the crevice corrosion in Alloy 22 induced by chloride. Current results fail to show in a consistent way a different effect on the repassivation potential of Alloy 22 for calcium chloride solutions than for sodium chloride solutions.

  7. Determination of the Crevice Repassivation Potential of Alloy 22 By a Potentiodynamic-Galvanostatic-Potentiostatic Method

    Energy Technology Data Exchange (ETDEWEB)

    K. Evans; L. Wong; R. Rebak

    2004-06-01

    Alloy 22 (N06022) is a nickel-based alloy highly resistant to corrosion. In some aggressive conditions of high chloride concentration, temperature and applied potential, Alloy 22 may suffer crevice corrosion, a form of localized corrosion. There are several electrochemical methods that can be used to determine localized corrosion in metallic alloys. One of the most popular for rapid screening is the cyclic potentiodynamic polarization (CPP). This work compares the results obtained by measuring the localized corrosion resistance of Alloy 22 using both CPP and the more cumbersome Tsujikawa-Hisamatsu Electrochemical (THE) method. The electrolytes used were 1 M NaCl and 5 M CaCl{sub 2}, both at 90 C. Results show that similar repassivation potentials were obtained for Alloy 22 using both methods. That is, in cases where localized corrosion is observed using the fast CPP method, there is no need to use THE method since it takes ten times longer to obtain comparable results in spite of the mode of corrosion attack is different in the tested specimens.

  8. A study of the potentials achieved during mechanical abrasion and the repassivation rate of titanium and Ti6A14V in inorganic buffer solutions and bovine serum

    Energy Technology Data Exchange (ETDEWEB)

    Contu, F. [University of Mississippi Medical Center, Jackson, MS (United States); Elsener, B. [University of Cagliari (Italy). Dept. of Inorganic and Anlaytical Chemistry; Swiss Federal Institute of Technology, Zurich (Switzerland). Institute of Materials Chemistry; Boehni, H. [Swiss Federal Institute of Technology, Zurich (Switzerland). Institute of Materials Chemistry

    2004-11-15

    Titanium alloys in orthopaedic implants are susceptible to mechanical disruption of the passive film (fretting corrosion). To study this effect, open-circuit potential (ocp) measurements before, during and after mechanical disruption of the passive film in a tribo-electrochemical cell on commercial pure titanium, and Ti6Al4V alloy in inorganic buffer solutions in the pH range from 2.0 to 12.0 and calf bovine serum at pH 4.0 and 7.0 are reported. Additionally, the effect of pH, electrolyte and sample composition on the repassivation rate has been investigated. The potentials achieved during the abrasion of Ti6Al4V are the same as those characterizing pure titanium, which indicates that the corrosion current of both materials in the active state is due to the oxidation of titanium. However, commercial pure titanium displays a tendency to repassivate faster than Ti6Al4V in inorganic buffer solutions thanks to the lower critical current density and the higher catalytic activity towards the hydrogen evolution reaction observed on the pure metal in comparison with the alloy. Proteinaceous solutions like bovine serum, significantly slow down the anodic dissolution and the cathodic reactions both on titanium and the alloy. However, the repassivation rate of the Ti6Al4V is not affected by serum, while that of cp titanium significantly decreases both at pH 4.0 and 7.0. (author)

  9. Crevice Repassivation Potentials for Alloy 22 in Simulated Concentrated Ground Waters

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B; Evans, K J; Ilevbare, G O

    2006-11-08

    The resistance of Alloy 22 (N06022) to localized corrosion, mainly crevice corrosion, has been extensively investigated in the last few years. However, the behavior of Alloy 22 in concentrated aqueous solutions that may simulate concentrated ground waters was not fully understood. Systematic electrochemical tests using cyclic potentiodynamic polarization as well as the Tsujikawa-Hisamatsu electrochemical method were performed to determine the crevice corrosion susceptibility of Alloy 22 in simulated concentrated water (SCW), simulated acidified water (SAW) and basic saturated water (BSW). Results show that Alloy 22 is immune to crevice corrosion in SCW and SAW but may suffer crevice corrosion initiation in BSW. Results also show that in a naturally aerated environment, the corrosion potential would never reach the critical potential for crevice corrosion initiation.

  10. Repassivation behavior of titanium in artificial saliva investigated with a photon rupture method

    Energy Technology Data Exchange (ETDEWEB)

    Sakairi, Masatoshi, E-mail: msakairi@eng.hokudai.ac.j [Faculty of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, 080-8628 (Japan); Kinjyo, Misaki [Graduate School of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, 080-8628 (Japan); Kikuchi, Tatsuya [Faculty of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, 080-8628 (Japan)

    2011-01-15

    Repassivation kinetics of titanium were investigated in artificial saliva by the photon rupture method, PRM, combined with anodizing. PRM uses focused pulsed Nd-YAG laser beam irradiation to remove oxide film and metal. The effects of the applied potential and F{sup -} ions on the repassivation kinetics of titanium were examined electrochemically. All conditions in this study use specimens that were repassivated within about 100 ms after the laser beam irradiation. The current transients after the laser beam irradiation showed a rapid increase, followed by a decrease with a slope of the log i vs. log t plots of about -1.5. The measured slope is steeper than what would be expected with the high field oxide film formation theory. This result suggests that the oxidation of titanium takes place through a combination of electrochemical and chemical reactions. More NaF results in a higher peak current density and amount of charge after laser beam irradiation. The influence of F{sup -} ions on the repassivation kinetics may be explained by localized pH changes caused by dissolution of titanium immediately after the laser beam irradiation.

  11. Repassivation Investigations on Aluminium: Physical Chemistry of the Passive State

    Science.gov (United States)

    Nagy, Tristan Oliver; Weimerskirch, Morris Jhängi Joseph; Pacher, Ulrich; Kautek, Wolfgang

    2016-09-01

    We show the temporal change in repassivation mechanism as a time-dependent linear combination of a high-field model of oxide growth (HFM) and the point defect model (PDM). The observed switch in transient repassivation current-decrease under potentiostatic control occurs independently of the active electrode size and effective repassivation time for all applied overpotentials. For that, in situ depassivation of plasma electrolytically oxidized (PEO) coatings on aluminium was performed with nanosecond laser pulses at 266 nm and the repassivation current transients were recorded as a function of pulse number. A mathematical model combines the well established theories of oxide-film formation and growth kinetics, giving insight in the non linear transient behaviour of micro-defect passivation. According to our findings, the repassivation process can be described as a charge consumption via two concurrent channels. While the major current-decay at the very beginning of the fast healing oxide follows a point-defect type exponential damping, the HFM mechanism supersedes gradually, the longer the repassivation evolves. Furthermore, the material seems to reminisce former laser treatments via defects built-in during depassivation, leading to a higher charge contribution of the PDM mechanism at higher pulse numbers.

  12. The Kinetics of Anodic Dissolution and Repassivation on 316L Stainless Steel in Borate Buffer Solution Studied by Abrading Electrode Technique

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    Xu, H. S.; Sun, D. B.; Yu, H. Y.; Meng, H. M. [University of Science and Technology Beijing, Beijing (China)

    2015-12-15

    The capacity of passive metal to repassivate after film damage determines the development of local corrosion and the resistance to corrosion failures. In this work, the repassivation kinetics of 316L stainless steel (316L SS) was investigated in borate buffer solution (pH 9.1) using a novel abrading electrode technique. The repassivation kinetics was analyzed in terms of the current density flowing from freshly bare 316L SS surface as measured by a potentiostatic method. During the early phase of decay (t < 2 s), according to the Avrami kinetics-based film growth model, the transient current was separated into anodic dissolution (i{sub diss}) and film formation (i{sub film}) components and analyzed individually. The film reformation rate and thickness were compared according to applied potential. Anodic dissolution initially dominated the repassivation for a short time, and the amount of dissolution increased with increasing applied potential in the passive region. Film growth at higher potentials occurred more rapidly compared to at lower potentials. Increasing the applied potential from 0 V{sub SCE} to 0.8 V{sub SCE} resulted in a thicker passive film (0.12 to 0.52 nm). If the oxide monolayer covered the entire bare surface (θ=1), the electric field strength through the thin passive film reached 1.6 x 10{sup 7} V/cm.

  13. Effect of sigma phase in the repassivation potential of austenitic-ferritic stainless steel SEW 410 Nr. 14517; Efeito da fase sigma no potencial de repassivacao do aco inoxidavel austeno-ferritico SEW 410 Nr. 14517

    Energy Technology Data Exchange (ETDEWEB)

    Itman Filho, A.; Pimenta, C.C.; Santos, C.M.L. [Instituto Federal do Espirito Santo, Vitoria (Brazil)], e-mail: andrei@ifes.edu.br; Casteletti, L.C. [Escola de Engenharia de Sao Carlos - EESC/USP, SP (Brazil)

    2010-07-01

    The austenitic-ferritic stainless steels, due to the optimum compromise between mechanical properties and corrosion resistance, are being used in many applications, as chemical and oil industries. In the oil exploitation, the effect of erosion-corrosion in acid environment is responsible for the increment in the equipment maintenance costs. Regarding the interest in researches of deep water oil exploitation, the proposal of this study was to evaluate the effect of the heat treatment at 850 degree C of the austenitic-ferritic stainless steel SEW 410 Nr.14517. Microstructural characterizations, microhardness measurements of the phases and corrosion tests were accomplished to evaluate the samples. The pitting potential values were obtained by galvanostatic tests in H{sub 2}SO{sub 4} acid solution. The results showed that the volumetric percentages of sigma phase increased while the ferritic phase percentages decreased, when the heat treatment time increased. The sigma phase promoted hardness increase with little corrosion resistance decrease in the austenitic-ferritic stainless steel, too. (author)

  14. THE EFFECT OF W ON THE REPASSIVATION BEHAVIOR OF Ni-ADDED STAINLESS STEELS

    Institute of Scientific and Technical Information of China (English)

    J.X. Pan; K. Y. Kim

    2005-01-01

    The effect of W on the repassivation behavior of Ni-added stainless steels was investigated with respect to the repassivation rate and the SCC susceptibility. It was found that more stable passive film was formed on the W-modified stainless steels than that of steels without W-modification, and the repassivation rate was faster for W-modified stainless steels in acidic chloride solution (0.5M H2SO4+3.5% Cl-). In neutral chloride solution (1M MgCl2), there were no significant differences on both passivation properties and the repassivation rates for duplex stainless steels,while W-modified austenite stainless steel showed faster repassivation rate. The SCC tests verified that W-modified Ni-added stainless steels exhibited better SCC resistance than steels without W in chloride solution. Moreover, W-modification in higher Ni-added stainless steels exhibited more remarkable SCC resistance than steels with lower Ni content in chloride solution.

  15. Influence of temperature and applied potential on the electrochemical behaviour of nickel in LiBr solutions by means of electrochemical impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Guinon-Pina, V.; Igual-Munoz, A. [Departamento de Ingenieria Quimica y Nuclear, ETSI Industriales, Universidad Politecnica de Valencia, P.O. Box 22012, E-46071 Valencia (Spain); Garcia-Anton, J. [Departamento de Ingenieria Quimica y Nuclear, ETSI Industriales, Universidad Politecnica de Valencia, P.O. Box 22012, E-46071 Valencia (Spain)], E-mail: jgarciaa@iqn.upv.es

    2009-10-15

    The effects of temperature, applied potential and hydrogen generation on the passive behaviour of nickel were investigated in lithium bromide aqueous solution using different electrochemical techniques: open circuit potential (OCP), potentiodynamic and potentiostatic measurements, and electrochemical impedance spectroscopy (EIS). From the polarization curves, it is observed that localised corrosion resistance decreases with temperature, the repassivation of nickel is more difficult at 75 {sup o}C and the hydrogen evolution reaction is favoured with an increase in temperature. Impedance results showed that the most suitable corrosion mechanism of nickel in LiBr solutions includes the double layer and the passive film formed on the nickel surface. The passive film of nickel partially disappears when a low cathodic potential is applied.

  16. Considerations on the repassivation of corroded reinforced concrete structures; Consideraciones sobre la repasivacion de las estructuras corroidas de hormigon armado

    Energy Technology Data Exchange (ETDEWEB)

    Cobo, A.; Gonzalez, M. N. [Escuela Universitaria de Arquitectura Tecnica de Madrid. Madrid (Spain); Otero, E.; Gonzalez, J. A. [Centro Nacional de Investigaciones Metalurgicas. CENIM. Madrid (Spain)

    2000-07-01

    An analysis is made of the responses of clean and precorroded steel electrodes in Ca(OH){sub 2} saturated solutions and in cement mortar, using gravimetric, metallographic and electrochemical techniques, essentially polarisation resistance measurements. The paper aims to answer some important questions about the corrosion of reinforced concrete structures (RCS) which, though seemingly elementary, continue to arouse controversy in scientific, technical and economical circles, such as the following: What corrosion rates are dangerous in RCS? What concrete resistivities guarantee sufficient durability of RCS?. Is it possible to detain corrosion once it has begun?. Can corroded RCS be repassivated? Are electrochemical RCS rehabilitation methods efficient, and if so, when? The results obtained indicate that electrochemical chloride removal and realkalisation cannot repassive heavily corroded steel surfaces, however they can be effective methods to prevent corrosion provided they are used before the transition from the passive state to the active one occurs. If applied to late, are useless for this purpose. (Author) 25 refs.

  17. The temperature acclimation potential of tropical bryophytes.

    Science.gov (United States)

    Wagner, S; Zotz, G; Bader, M Y

    2014-01-01

    Bryophyte biomass and diversity in tropical moist forests decrease dramatically from higher altitudes towards the lowlands. High respiratory carbon losses at high temperatures may partly explain this pattern, if montane species are unable to acclimatise their metabolic rates to lowland temperatures. We transplanted ten bryophyte species from two altitudes (1200 and 500 m a.s.l.) to lower (warmer) altitudes (500 m and sea level) in Panama. We studied short-term temperature acclimation of CO2 exchange for 2.5 months, and survival and growth for 21 months following transplantation. Short-term acclimation did not occur, and on a longer time scale mortality was highest and growth lowest in the transplanted samples. A few transplanted samples of most species, however, survived the whole experiment and finished with growth rates similar to controls. This recovery of growth rate suggests temperature acclimation, in spite of no measurable metabolic changes in smaller random samples. This acclimation even compensated for shorter periods of CO2 uptake due to more rapid drying. Nevertheless, these species are not abundant in lowland forests, perhaps due to dispersal or establishment limitation. The apparent heterogeneity of the acclimation potential within species may allow populations to adapt locally and avoid being forced uphill under climatic warming.

  18. High temperature alloys: their exploitable potential

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, J.B.; Merz, M.; Nihoul, J.; Ward, J. (eds.) (Commission of the European Communities, Petten (Netherlands). Joint Nuclear Research Center; NET-TEAM, Garching (DE))

    1987-01-01

    This book is the proceedings of a conference dealing with fundamental and technical aspects of the applications of high temperature alloys. It is split into five sections which cover the opening session of the conference and four further sessions covering: the theoretical and practical limits for HT alloys; the potential for development in alloys and processing; engineering considerations; the future outlook. The different sessions each included a number of invited papers followed by a series of posters and were concluded by a presentation of a 'synthesis' by a session rapporteur and general discussion. This structure is retained in the proceedings, including the discussion points in those cases where the authors have provided written answers to the questions raised. This book will be of interest to metallurgists, materials scientists, physicists and research workers in high temperature materials.

  19. Evaluation of the absolute regional temperature potential

    Directory of Open Access Journals (Sweden)

    D. T. Shindell

    2012-09-01

    Full Text Available The Absolute Regional Temperature Potential (ARTP is one of the few climate metrics that provides estimates of impacts at a sub-global scale. The ARTP presented here gives the time-dependent temperature response in four latitude bands (90–28° S, 28° S–28° N, 28–60° N and 60–90° N as a function of emissions based on the forcing in those bands caused by the emissions. It is based on a large set of simulations performed with a single atmosphere-ocean climate model to derive regional forcing/response relationships. Here I evaluate the robustness of those relationships using the forcing/response portion of the ARTP to estimate regional temperature responses to the historic aerosol forcing in three independent climate models. These ARTP results are in good accord with the actual responses in those models. Nearly all ARTP estimates fall within ±20% of the actual responses, though there are some exceptions for 90–28° S and the Arctic, and in the latter the ARTP may vary with forcing agent. However, for the tropics and the Northern Hemisphere mid-latitudes in particular, the ±20% range appears to be roughly consistent with the 95% confidence interval. Land areas within these two bands respond 39–45% and 9–39% more than the latitude band as a whole. The ARTP, presented here in a slightly revised form, thus appears to provide a relatively robust estimate for the responses of large-scale latitude bands and land areas within those bands to inhomogeneous radiative forcing and thus potentially to emissions as well. Hence this metric could allow rapid evaluation of the effects of emissions policies at a finer scale than global metrics without requiring use of a full climate model.

  20. Potential aerospace applications of high temperature superconductors

    Science.gov (United States)

    Selim, Raouf

    1994-01-01

    The recent discovery of High Temperature Superconductors (HTS) with superconducting transition temperature, T(sub c), above the boiling point of liquid nitrogen has opened the door for using these materials in new and practical applications. These materials have zero resistance to electric current, have the capability of carrying large currents and as such have the potential to be used in high magnetic field applications. One of the space applications that can use superconductors is electromagnetic launch of payloads to low-earth-orbit. An electromagnetic gun-type launcher can be used in small payload systems that are launched at very high velocity, while sled-type magnetically levitated launcher can be used to launch larger payloads at smaller velocities. Both types of launchers are being studied by NASA and the aerospace industry. The use of superconductors will be essential in any of these types of launchers in order to produce the large magnetic fields required to obtain large thrust forces. Low Temperature Superconductor (LTS) technology is mature enough and can be easily integrated in such systems. As for the HTS, many leading companies are currently producing HTS coils and magnets that potentially can be mass-produced for these launchers. It seems that designing and building a small-scale electromagnetic launcher is the next logical step toward seriously considering this method for launching payloads into low-earth-orbit. A second potential application is the use of HTS to build sensitive portable devices for the use in Non Destructive Evaluation (NDE). Superconducting Quantum Interference Devices (SQUID's) are the most sensitive instruments for measuring changes in magnetic flux. By using HTS in SQUID's, one will be able to design a portable unit that uses liquid nitrogen or a cryocooler pump to explore the use of gradiometers or magnetometers to detect deep cracks or corrosion in structures. A third use is the replacement of Infra-Red (IR) sensor leads on

  1. A Consensus on Mantle Potential Temperatures? (Invited)

    Science.gov (United States)

    Putirka, K. D.

    2009-12-01

    Recent publications may indicate a mounting consensus regarding mantle temperatures - an agreement that can be crucial for improving our understanding of mantle dynamics. To compare temperatures at various localities, McKenzie & Bickle (1988) proposed the concept of a mantle potential temperature (Tp) as a reference; Tp is the temperature the mantle would have at the surface, if it ascended along an adiabat without undergoing melting. Perhaps the most precise method to estimate Tp involves estimating the conditions of partial melting, and then correcting for the heat of fusion. The several sources of error include estimation of: a parental liquid, an equilibrium mantle olivine, the degree of partial melting (F), and the depth at which the parental melt is generated. There is also model error inherent to any thermometer. And when correcting for the heat of fusion we assume that we are correcting up to the convective adiabat, but if the parental melt was generated within the conductive lithosphere, Tp will be low. In any case, if we accept that the highest Tp estimates at Hawaii are of most interest (since magmas generated away from a plume centerline will not reflect the full heat content of a high T source), then in spite of these sources of error, recent estimates, published over a span of 10 months by three independent research groups, indicate considerable convergence. At Hawaii maximum Tp values are: 1600 deg. C by Herzberg & Asimow (2008), ca. 1630 deg. C by Lee et al. (2009; their Fig. 2B), and using two slightly different equation sets, 1687 deg. C by Putirka (2008; Geology) and 1660 deg. C by Putirka (2008; RiMG volume 69), yielding an average of 1644±38oC. Similarly, there is convergence for mean Tp at MORs (accepting that MORs are not isothermal; Klein and Langmuir, 1987): Herzberg & Asimow (2008) and Lee et al. (2009) estimate that Tp is ca. 1350 deg. C, and Putirka (2008; Geology) estimates a Tp of 1396 deg. C; these estimates average to 1365±26o

  2. Determination of Land Surface Temperature (LST) and Potential ...

    African Journals Online (AJOL)

    Determination of Land Surface Temperature (LST) and Potential Urban Heat Island Effect in Parts of Lagos State using Satellite ... Changes in temperature appear to be closely related to concentrations of atmospheric carbon dioxide.

  3. The Variation of Electrochemical Cell Potentials with Temperature

    Science.gov (United States)

    Peckham, Gavin D.; McNaught, Ian J.

    2011-01-01

    Electrochemical cell potentials have no simple relationship with temperature but depend on the interplay between the sign and magnitude of the isothermal temperature coefficient, dE[degrees]/dT, and on the magnitude of the reaction quotient, Q. The variations in possible responses of standard and non-standard cell potentials to changes in the…

  4. Gravitational Coleman–Weinberg potential and its finite temperature counterpart

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, Srijit [Astroparticle Physics and Cosmology Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Discipline of Physics, Indian Institute of Technology Gandhinagar, Ahmedabad, Gujarat 382424 (India); Majumdar, Parthasarathi [Department of Physics, Ramakrishna Mission Vivekananada University, Belur Math, Howrah 711202 (India)

    2014-08-15

    Coleman–Weinberg (CW) phenomena for the case of gravitons minimally coupled to massless scalar field is studied. The one-loop effect completely vanishes if there is no self-interaction term present in the matter sector. The one-loop effective potential is shown to develop an instability in the form of acquiring an imaginary part, which can be traced to the tachyonic pole in the graviton propagator. The finite temperature counterpart of this CW potential is computed to study the behaviour of the potential in the high and low temperature regimes with respect to the typical energy scale of the theory. Finite temperature contribution to the imaginary part of gravitational CW potential exhibits a damped oscillatory behaviour; all thermal effects are damped out as the temperature vanishes, consistent with the zero-temperature result.

  5. Rising soil temperature in China and its potential ecological impact

    Science.gov (United States)

    Zhang, Hui; Wang, Enli; Zhou, Daowei; Luo, Zhongkui; Zhang, Zhengxiang

    2016-01-01

    Global warming influences a series of ecological processes and ecosystems’ stability. Although comprehensive studies have been done to investigate responses of various ecosystem processes to rising air temperatures, less is known about changes in soil temperatures and their impact on below-ground processes, particularly in deep layers. Herein, we used 50 y of temperature data (1962–2011) from 360 sites in China to assess spatio-temporal changes in soil temperatures from the surface to a depth of 3.20 m. We determined, apparently for the first time, that soil surface temperature increased 31% more than air temperature, potentially leading to more carbon release to the atmosphere than predicted. Annual mean surface temperature increased by 2.07–4.04 and 0.66–2.21 °C in northern and southern China, respectively, with the greatest in winter. Warming occurred as deep as 3.20 m. The soil temperature rise was predicted to have increased soil respiration by up to 28%, reinforcing climate warming and extending the potential growing season by up to 20 d across China. However, use of only air temperature to estimate soil temperature changes would underestimate those impacts. In conclusion, these results highlighted the importance of soil warming and of using soil temperature to assess and predict soil processes. PMID:27765953

  6. Rising soil temperature in China and its potential ecological impact

    Science.gov (United States)

    Zhang, Hui; Wang, Enli; Zhou, Daowei; Luo, Zhongkui; Zhang, Zhengxiang

    2016-10-01

    Global warming influences a series of ecological processes and ecosystems’ stability. Although comprehensive studies have been done to investigate responses of various ecosystem processes to rising air temperatures, less is known about changes in soil temperatures and their impact on below-ground processes, particularly in deep layers. Herein, we used 50 y of temperature data (1962–2011) from 360 sites in China to assess spatio-temporal changes in soil temperatures from the surface to a depth of 3.20 m. We determined, apparently for the first time, that soil surface temperature increased 31% more than air temperature, potentially leading to more carbon release to the atmosphere than predicted. Annual mean surface temperature increased by 2.07–4.04 and 0.66–2.21 °C in northern and southern China, respectively, with the greatest in winter. Warming occurred as deep as 3.20 m. The soil temperature rise was predicted to have increased soil respiration by up to 28%, reinforcing climate warming and extending the potential growing season by up to 20 d across China. However, use of only air temperature to estimate soil temperature changes would underestimate those impacts. In conclusion, these results highlighted the importance of soil warming and of using soil temperature to assess and predict soil processes.

  7. Turkey's High Temperature Geothermal Energy Resources and Electricity Production Potential

    Science.gov (United States)

    Bilgin, Ö.

    2012-04-01

    Turkey is in the first 7 countries in the world in terms of potential and applications. Geothermal energy which is an alternative energy resource has advantages such as low-cost, clean, safe and natural resource. Geothermal energy is defined as hot water and steam which is formed by heat that accumulated in various depths of the Earth's crust; with more than 20oC temperature and which contain more than fused minerals, various salts and gases than normal underground and ground water. It is divided into three groups as low, medium and high temperature. High-temperature fluid is used in electricity generation, low and medium temperature fluids are used in greenhouses, houses, airport runways, animal farms and places such as swimming pools heating. In this study high temperature geothermal fields in Turkey which is suitable for electricity production, properties and electricity production potential was investigated.

  8. Extreme temperature days and potential impacts in Southern Europe

    Directory of Open Access Journals (Sweden)

    A. Cardil

    2014-06-01

    Full Text Available Extreme temperature events have consequences for human health and mortality, forest disturbance patterns, agricultural productivity, and the economic repercussions of these consequences combined. To gain insight into whether extreme temperature events are changing in light of global climate dynamics, the annual numbers of high temperature days (those with temperatures higher than 20, 22.5 and 25 °C at 850 hPa were analyzed across Southern Europe from years 1978–2012. A significant increase in the frequency of these days was found in many areas over the time period analyzed, and patterns in the spatial distribution of these changes were identified. We discuss the potential consequences of the increases in high temperature days with regards to forest fire risk, human health, agriculture, energy demands, and some potential economic repercussions.

  9. Effective potentials for atom-atom interaction at low temperatures

    OpenAIRE

    Gao, Bo

    2002-01-01

    We discuss the concept and design of effective atom-atom potentials that accurately describe any physical processes involving only states around the threshold. The existence of such potentials gives hope to a quantitative, and systematic, understanding of quantum few-atom and quantum many-atom systems at relatively low temperatures.

  10. Relationship between Microstructure and Corrosion Behavior of Martensitic High Nitrogen Stainless Steel 30Cr15Mo1N at Different Austenitizing Temperatures.

    Science.gov (United States)

    Jiang, Zhouhua; Feng, Hao; Li, Huabing; Zhu, Hongchun; Zhang, Shucai; Zhang, Binbin; Han, Yu; Zhang, Tao; Xu, Dake

    2017-07-27

    The relationship between microstructure and corrosion behavior of martensitic high nitrogen stainless steel 30Cr15Mo1N at different austenitizing temperatures was investigated by microscopy observation, electrochemical measurement, X-ray photoelectron spectroscopy analysis and immersion testing. The results indicated that finer Cr-rich M₂N dispersed more homogeneously than coarse M23C₆, and the fractions of M23C₆ and M₂N both decreased with increasing austenitizing temperature. The Cr-depleted zone around M23C₆ was wider and its minimum Cr concentration was lower than M₂N. The metastable pits initiated preferentially around coarse M23C₆ which induced severer Cr-depletion, and the pit growth followed the power law. The increasing of austenitizing temperature induced fewer metastable pit initiation sites, more uniform element distribution and higher contents of Cr, Mo and N in the matrix. In addition, the passive film thickened and Cr₂O₃, Cr(3+) and CrN enriched with increasing austenitizing temperature, which enhanced the stability of the passive film and repassivation ability of pits. Therefore, as austenitizing temperature increased, the metastable and stable pitting potentials increased and pit growth rate decreased, revealing less susceptible metastable pit initiation, larger repassivation tendency and higher corrosion resistance. The determining factor of pitting potentials could be divided into three stages: dissolution of M23C₆ (below 1000 °C), dissolution of M₂N (from 1000 to 1050 °C) and existence of a few undissolved precipitates and non-metallic inclusions (above 1050 °C).

  11. Warm body temperature facilitates energy efficient cortical action potentials.

    Directory of Open Access Journals (Sweden)

    Yuguo Yu

    Full Text Available The energy efficiency of neural signal transmission is important not only as a limiting factor in brain architecture, but it also influences the interpretation of functional brain imaging signals. Action potential generation in mammalian, versus invertebrate, axons is remarkably energy efficient. Here we demonstrate that this increase in energy efficiency is due largely to a warmer body temperature. Increases in temperature result in an exponential increase in energy efficiency for single action potentials by increasing the rate of Na(+ channel inactivation, resulting in a marked reduction in overlap of the inward Na(+, and outward K(+, currents and a shortening of action potential duration. This increase in single spike efficiency is, however, counterbalanced by a temperature-dependent decrease in the amplitude and duration of the spike afterhyperpolarization, resulting in a nonlinear increase in the spike firing rate, particularly at temperatures above approximately 35°C. Interestingly, the total energy cost, as measured by the multiplication of total Na(+ entry per spike and average firing rate in response to a constant input, reaches a global minimum between 37-42°C. Our results indicate that increases in temperature result in an unexpected increase in energy efficiency, especially near normal body temperature, thus allowing the brain to utilize an energy efficient neural code.

  12. Stochastic joint inversion of temperature and self-potential data

    Science.gov (United States)

    Jardani, A.; Revil, A.

    2009-10-01

    The flow of the ground water is responsible for both thermal and self-potential anomalies. Temperature is usually recorded in boreholes while self-potential is usually recorded at the ground surface of the Earth. This makes the joint inversion of temperature and self-potential data together an attractive approach to invert permeability. We use an Adaptive Metropolis Algorithm to determine the posterior probability densities of the material properties of different geological formations and faults by inverting jointly self-potential and temperature data. The algorithm is tested using a synthetic case corresponding to a series of sedimentary layers overlying a low-permeability granitic substratum. The flow of the ground water (computed in steady-state condition) is mainly localized in two faults acting as preferential fluid flow pathways. The first fault is discharging warmed ground water near the ground surface while the second fault acts as a recharge zone of cold water (a classical scenario in geothermal systems). The joint inversion algorithm yield accurate estimate of the permeability of the different units only if both temperature and self-potential data are jointly inverted. An application using real data is also performed. It concerns the upwelling of a hydrothermal plume through a set of faults and permeable formations at the Cerro Prieto geothermal field in Baja California. The optimized permeabilities are in close agreement with independent hydrogeological estimates.

  13. Estimating Potential Evapotranspiration by Missing Temperature Data Reconstruction

    Directory of Open Access Journals (Sweden)

    Eladio Delgadillo-Ruiz

    2015-01-01

    Full Text Available This work studies the statistical characteristics of potential evapotranspiration calculations and their relevance within the water balance used to determine water availability in hydrological basins. The purpose of this study was as follows: first, to apply a missing data reconstruction scheme in weather stations of the Rio Queretaro basin; second, to reduce the generated uncertainty of temperature data: mean, minimum, and maximum values in the evapotranspiration calculation which has a paramount importance in the manner of obtaining the water balance at any hydrological basin. The reconstruction of missing data was carried out in three steps: (1 application of a 4-parameter sinusoidal type regression to temperature data, (2 linear regression to residuals to obtain a regional behavior, and (3 estimation of missing temperature values for a certain year and during a certain season within the basin under study; estimated and observed temperature values were compared. Finally, using the obtained temperature values, the methods of Hamon, Papadakis, Blaney and Criddle, Thornthwaite, and Hargreaves were employed to calculate potential evapotranspiration that was compared to the real observed values in weather stations. With the results obtained from the application of this procedure, the surface water balance was corrected for the case study.

  14. Aspects of Holographic Entanglement at Finite Temperature and Chemical Potential

    CERN Document Server

    Kundu, Sandipan

    2016-01-01

    We investigate the behavior of entanglement entropy at finite temperature and chemical potential for strongly coupled large-N gauge theories in $d$-dimensions ($d\\ge 3$) that are dual to Anti-de Sitter-Reissner-Nordstrom geometries in $(d+1)-$dimensions, in the context of gauge-gravity duality. We develop systematic expansions based on the Ryu-Takayanagi prescription that enable us to derive analytic expressions for entanglement entropy and mutual information in different regimes of interest. Consequently, we identify the specific regions of the bulk geometry that contribute most significantly to the entanglement entropy of the boundary theory at different limits. We define a scale, dubbed as the effective temperature, which determines the behavior of entanglement in different regimes. At high effective temperature, entanglement entropy is dominated by the thermodynamic entropy, however, mutual information subtracts out this contribution and measures the actual quantum entanglement. Finally, we study the enta...

  15. Potential impact of high temperature superconductors on MAGLEV transportation

    Science.gov (United States)

    Hull, J. R.

    1992-02-01

    This report describes the potential impact that high-temperature superconductors (HTS's) may have on transportation by magnetically levitated vehicles. It is not intended as a planning document, but rather as an overview of potential HTS applications to magnetic-levitation (maglev) transportation. The present maglev program in the United States is summarized, and the present status of development of HTS's is described. Areas identified for possible impact on maglev technology are: (1) liquid-nitrogen-cooled levitation magnets; (2) magnetic-field shielding of the passenger compartment; (3) superconducting magnetic energy storage for wayside power; (4) superconducting bearings for flywheel energy storage for wayside power; (5) downleads to continuously powered liquid-helium-cooled levitation magnets; and (6) liquid-hydrogen-cooled levitation magnets and linear motor propulsion windings. Major technical issues that remain to be resolved for the use of HTS's in maglev applications include thermal magnetic stability, mechanical properties, and critical current density at liquid-nitrogen temperatures.

  16. Temperature-dependent potential in cluster-decay process

    Science.gov (United States)

    Gharaei, R.; Zanganeh, V.

    2016-08-01

    Role of the thermal effects of the parent nucleus in the Coulomb barrier and the half-life of 28 cluster-decays is systematically analyzed within the framework of the proximity formalism, namely proximity potential 2010. The WKB approximation is used to determine the penetration probability of the emitted cluster. It is shown that the height and width of the Coulomb barrier in the temperature-dependent proximity potential are less than its temperature-independent version. Moreover, this investigation reveals that the calculated values of half-life for selected cluster-decays are in better agreement with the experimental data when the mentioned effects are imposed on the proximity approach. A discussion is also presented about the predictions of the present thermal approach for cluster-decay half-lives of the super-heavy-elements.

  17. Potential impact of high temperature superconductors on maglev transportation

    Energy Technology Data Exchange (ETDEWEB)

    Hull, J.R.

    1992-02-01

    This report describes the potential impact that high-temperature superconductors (HTSs) may have on transportation by magnetically levitated vehicles. It is not intended as a planning document, but rather as an overview of potential HTS applications to magnetic-levitation (maglev) transportation. The present maglev program in the United States is summarized, and the present status of development of HTSs is described. Areas identified for possible impact on maglev technology are (1) liquid-nitrogen-cooled levitation magnets, (2) magnetic-field shielding of the passenger compartment, (3) superconducting magnetic energy storage for wayside power, (4) superconducting bearings for flywheel energy storage for wayside power, (5) downleads to continuously powered liquid-helium-cooled levitation magnets, and (6) liquid-hydrogen-cooled levitation magnets and linear motor propulsion windings. Major technical issues that remain to be resolved for the use of HTSs in maglev applications include thermal magnetic stability, mechanical properties, and critical current density at liquid-nitrogen temperatures.

  18. Impurity diffusion in a harmonic potential and nonhomogeneous temperature

    Science.gov (United States)

    Aragie, Berhanu; Asfaw, Mesfin; Demeyu, Lemi; Bekele, Mulugeta

    2014-09-01

    We propose different ways of manipulating the dispersion of impurities along a semiconductor layer during heat treatment. The impurities undergo a random walk assisted by a nonlinear harmonic potential and nonhomogeneous temperature. Depending on the strength of a hot spot, trap potential, impurity density and standard deviation of the hot spot, the impurities diffuse away from the central region and pile up around the peripheral region of the semiconductor layer. Furthermore, the numerical result depicts that the internal field at high doping level can be of sufficient strength to cause the broadening of the impurity profile.

  19. QCD Effective action at high temperature and small chemical potential

    CERN Document Server

    Villavicencio, C

    2007-01-01

    We present a construction of an effective Yang-Mills action for QCD, from the expansion of the fermionic determinant in terms of powers of the chemical potential at high temperature, for the case of massless quarks. We analyze this expansion in the perturbative region and find that it gives extra spurious information. We propose for the non-perturbative sector a simplified effective action which, in principle, contains only the relevant information.

  20. Low reheating temperatures in monomial and binomial inflationary potentials

    CERN Document Server

    Rehagen, Thomas

    2015-01-01

    We investigate the allowed range of reheating temperature values in light of the Planck 2015 results and the recent joint analysis of Cosmic Microwave Background (CMB) data from the BICEP2/Keck Array and Planck experiments, using monomial and binomial inflationary potentials. While the well studied $\\phi^2$ inflationary potential is no longer favored by current CMB data, as well as $\\phi^p$ with $p>2$, a $\\phi^1$ potential and canonical reheating ($w_{re}=0$) provide a good fit to the CMB measurements. In this last case, we find that the Planck 2015 $68\\%$ confidence limit upper bound on the spectral index, $n_s$, implies an upper bound on the reheating temperature of $T_{re}\\lesssim 6\\times 10^{10}\\,{\\rm GeV}$, and excludes instantaneous reheating. The low reheating temperatures allowed by this model open the possiblity that dark matter could be produced during the reheating period instead of when the Universe is radiation dominated, which could lead to very different predictions for the relic density and mo...

  1. Effect of YSZ sintering temperature on mixed potential sensor performance

    Energy Technology Data Exchange (ETDEWEB)

    Sekhar, Praveen K [Los Alamos National Laboratory; Brosha, Eric L [Los Alamos National Laboratory; Rangachary, Mukundan [Los Alamos National Laboratory; Garzon, Fernando H [Los Alamos National Laboratory; Nelson, Mark A [Los Alamos National Laboratory; Toracco, Dennis [Los Alamos National Laboratory

    2009-01-01

    In this article, the influence of Yttria-Stabilized Zirconia (YSZ) sintering temperature on a Pt/YSZ/La{sub 0.8}Sr{sub 0.2}CrO{sub 3} mixed potential sensor performance is reported. The sintering temperature of YSZ was varied from 1000 to 1200 C. Mercury porosity measurements were performed to estimate the porosity and tortuosity of the YSZ sample as a function of sintering temperature. Further, the surface area of YSZ was computed by the BET method. After YSZ characterization, the unbiased and biased sensor response was recorded. The 1000 C sintered YSZ sample was taken as the reference for comparison purposes. Experimental results indicated a 30% reduction in porosity for the 1200 C sintered YSZ sample, accounting for a 14-fold increase in the sensor response rise time. In addition, for the same sample, a 13-fold increase in sensitivity was observed upon exposure to propylene (100 ppm), associated with a 76% reduction in surface area. The slow response time of the sensor with YSZ sintered at higher temperatures has been attributed to higher tortuosity (delay in gas permeation to the three phase interface). Whereas, reduced heterogeneous catalysis induced by lower surface area accounts for the rise in sensitivity levels. The optimum YSZ sintering temperature was found to lie between 1100 and 1150 C.

  2. High temperature solar furnace: current applications and future potential

    Energy Technology Data Exchange (ETDEWEB)

    Bjorndalen, N. [Dalhousie Univ., Faculty of Engineering, Halifax, NS (Canada)

    2003-02-15

    The high temperature solar furnace can offer great opportunities for the production of many types of products worldwide, but recent advances in this technology have been limited to metal reduction. The production of semiconductors, which are utilized to a great extent in the electronic industry, is a viable option for this technology that has been overlooked. Especially where sand and sunlight are plentiful (countries that surround the equator), silicon chips produced with a solar furnace can have great economical value. This paper describes current and potential solar furnace technologies. The components of the solar furnace are described, as well as metal reduction processes including zinc and aluminum production. The viability of silicon chip production is also examined. The possibilities for other product development using an extremely (up to 10,000 deg C) high temperature solar furnace are also discussed. Economically, the benefits of solar furnaces are great, with only high initial start-up costs and little operation costs. Metal reduction processes can also be enhanced with high temperature solar furnaces in that plugging problems are eliminated. By replacing conventional furnaces, such as blast and electric arc furnaces, with a high temperature solar furnace, CO{sub 2} emissions and energy consumption can be greatly reduced, which will bring in added dividends to the society. (Author)

  3. Photochemistry at high temperatures - potential of ZnO as a high temperature photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Schubnell, M.; Beaud, P.; Kamber, I. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Direct conversion of solar radiation into useful, storeable and transportable chemical products is the primary goal of solar chemistry. In this paper we discuss some fundamental aspects of photochemistry at elevated temperatures. We show that luminescence can serve as an indicator of the potential use of a system as a photoconverter. As an example we present experimental data on the chemical potential and on the lifetime of the excited states of ZnO. The low luminescence quantum yield together with a lifetime of about 200 ps indicate that an efficient photochemical conversion on ZnO is highly improbable. We believe this to be a general feature of chemical systems based on a semiconductor photocatalyst, in particular of photoreactions at a solid/gas interface. (author) 3 figs., 6 refs

  4. Assessment of potential solder candidates for high temperature applications

    DEFF Research Database (Denmark)

    of the package with different solders of different melting temperatures. High Pb containing alloys where the lead levels can be above 85% by weight, is one of the solders currently being used in this technology. Responding to market pressure i.e. need for green electronic products there is now an increasing...

  5. Passivation and corrosion of the high performance materials alloy 33, alloy 31 and nickel in LiBr solution at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Igual Munoz, A.; Garcia Anton, J.; Guinon, J.L.; Perez Herranz, V. [Departamento de Ingenieria Quimica y Nuclear. E.T.S. Industriales, Universidad Politecnica de Valencia, P.O. Box 22012, E-46071 Valencia (Spain)

    2004-07-01

    Aqueous solutions containing high concentrations of Lithium Bromide are employed as absorbent solutions for almost all types of heating and refrigerating absorption systems that use natural gas or steam as energy sources. LiBr solutions can cause serious corrosion problems in common metallic components. The objective of the present work was to study the corrosion resistance of new high alloyed materials in commercial LiBr heavy brine solution (which contains chromate as inhibitor), at different temperatures (25, 30, 40, 50, 60, 70 and 80 deg. C). The materials tested were stainless steels Alloy 33 (UNS R20033), a new corrosion resistant austenitic material alloyed with nominally (wt%) 33 Cr, 32 Fe, 31 Ni; Nicrofer 3127 hMo-alloy 31 (UNS N08031), an iron-nickel-chromium-molybdenum alloy with nitrogen; and pure Nickel. Corrosion resistance was estimated from the cyclic potentiodynamic polarization curves, comparing OCP values, calculating corrosion potentials and current rates from Tafel analysis; in order to characterize the passivating behaviour of the alloys the study was completed with the analysis of the pitting potentials, passivating current and re-passivating properties at the temperatures under study. Passivating properties are well observed in all the samples in commercial LiBr solution at all temperatures. In these cases, passivation properties decrease with temperature. (authors)

  6. High-temperature membrane reactors: potential and problems

    NARCIS (Netherlands)

    Saracco, G.; Neomagus, H.W.J.P.; Versteeg, G.F.; Swaaij, van W.P.M.

    1999-01-01

    The most recent literature in the field of membrane reactors is reviewed, four years after an analogous effort of ours (Saracco et al., 1994), describing shortly the potentials of these reactors, which now seem to be well established, and focusing mostly on problems towards practical exploitation. S

  7. High-temperature membrane reactors : potential and problems

    NARCIS (Netherlands)

    Saracco, G.; Neomagus, H.W.J.P.; Versteeg, G.F.; Swaaij, W.P.M. van

    1999-01-01

    The most recent literature in the field of membrane reactors is reviewed, four years after an analogous effort of ours, describing shortly the potentials of these reactors, which now seem to be well established, and focusing mostly on problems towards practical exploitation. Since then, progress has

  8. Higher spin entanglement entropy at finite temperature with chemical potential

    CERN Document Server

    Chen, Bin

    2016-01-01

    It is generally believed that the semiclassical AdS$_3$ higher spin gravity could be described by a two dimensional conformal field theory with ${\\cal{W}}$-algebra symmetry in the large central charge limit. In this paper, we study the single interval entanglement entropy on the torus in the CFT with a ${\\cW}_3$ deformation. More generally we develop the monodromy analysis to compute the two-point function of the light operators under a thermal density matrix with a ${\\cW}_3$ chemical potential to the leading order. Holographically we compute the probe action of the Wilson line in the background of the spin-3 black hole with a chemical potential. We find exact agreement.

  9. Linear Sigma Model at Finite Temperature and Baryonic Chemical Potential Using the N-Midpoint Technique

    Directory of Open Access Journals (Sweden)

    M. Abu-Shady

    2014-01-01

    Full Text Available A baryonic chemical potential (μb is included in the linear sigma model at finite temperature. The effective mesonic potential is numerically calculated using the N-midpoint rule. The meson masses are investigated as functions of the temperature (T at fixed value of baryonic chemical potential. The pressure and energy density are investigated as functions of temperature at fi…xed value of μb. The obtained results are in good agreement in comparison with other techniques. We conclude that the calculated effective potential successfully predicts the meson properties and thermodynamic properties at finite baryonic chemical potential.

  10. Some potential antenna applications of high-temperature superconductors

    Science.gov (United States)

    Dinger, Robert J.

    1990-09-01

    A review of possible applications of high temperature superconductors (HTS) to antennas and antenna feed networks is presented. The frequency range of consideration is 1 MHz to 100 GHz. Three antenna application areas seem appropriate for HTS material. (1) Electrically small antennas and their matching networks: an increase in efficiency is possible for electrically short antennas, but at the expense of bandwidth. Substantial radiated power levels (on the order of kilowatts) can be handled by the best HTS material. Substantial improvement may be realized by making only the matching network of HTS material. (2) Feed and matching networks for compact arrays with enhanced directive gain (superdirective arrays): HTS material should permit such arrays to be fabricated that have high efficiency. (3) Feed networks for millimeter-wave arrays: Low-loss feed networks using HTS microstrip transmission lines give many decibels improvement in gain.

  11. Assessment of potential solder candidates for high temperature applications

    DEFF Research Database (Denmark)

    Multi-Chip module (MCM) technology is a specialized electronic packaging technology recently gaining momentum due to the miniaturization drive in the microelectronics industry. The step soldering approach is being employed in the MCM technology. This method is used to solder various levels...... of the package with different solders of different melting temperatures. High Pb containing alloys where the lead levels can be above 85% by weight, is one of the solders currently being used in this technology. Responding to market pressure i.e. need for green electronic products there is now an increasing...... criterion, phases predicted in the bulk solder and the thermodynamic stability of chlorides. These promising solder candidates were precisely produced using the hot stage microscope and its respective anodic and cathodic polarization curves were investigated using a micro-electrochemical set up...

  12. Peltier Effect and Electron Temperature Distribution in Quantum Hall Systems with Potential Discontinuity

    Science.gov (United States)

    Nakagawa, Takahiro; Akera, Hiroshi; Suzuura, Hidekatsu

    2005-06-01

    Spatial variations of the electron temperature are calculated in the linear-response regime in a quantum Hall system with a potential discontinuity in the current direction. It is shown that the sign of the induced deviation of the electron temperature from the lattice temperature exhibits quantum oscillations.

  13. A Student-Constructed Galvanic Cell for the Measurement of Cell Potentials at Different Temperatures

    Science.gov (United States)

    Jakubowska, Anna

    2016-01-01

    A student-made galvanic cell is proposed for temperature measurements of cell potential. This cell can be easily constructed by students, the materials needed are readily available and nontoxic, and the solution applied is in an attractive color. For this cell, the potential values are excellently reproducible at each temperature, and the…

  14. A Student-Constructed Galvanic Cell for the Measurement of Cell Potentials at Different Temperatures

    Science.gov (United States)

    Jakubowska, Anna

    2016-01-01

    A student-made galvanic cell is proposed for temperature measurements of cell potential. This cell can be easily constructed by students, the materials needed are readily available and nontoxic, and the solution applied is in an attractive color. For this cell, the potential values are excellently reproducible at each temperature, and the…

  15. Three-loop HTLpt thermodynamics at finite temperature and chemical potential

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Najmul; Bandyopadhyay, Aritra [Theory Division, Saha Institute of Nuclear Physics,1/AF Bidhannagar, Kolkata-700107 (India); Andersen, Jens O. [Department of Physics, Norwegian University of Science and Technology,N-7491 Trondheim (Norway); Mustafa, Munshi G. [Theory Division, Saha Institute of Nuclear Physics,1/AF Bidhannagar, Kolkata-700107 (India); Strickland, Michael [Department of Physics, Kent State University,Kent, Ohio 44242 (United States); Su, Nan [Faculty of Physics, University of Bielefeld,D-33615 Bielefeld (Germany)

    2014-05-07

    We calculate the three-loop thermodynamic potential of QCD at finite temperature and chemical potential(s) using the hard-thermal-loop perturbation theory (HTLpt) reorganization of finite temperature and density QCD. The resulting analytic thermodynamic potential allows us to compute the pressure, energy density, and entropy density of the quark-gluon plasma. Using these we calculate the trace anomaly, speed of sound, and second-, fourth-, and sixth-order quark number susceptibilities. For all observables considered we find good agreement between our three-loop HTLpt calculations and available lattice data for temperatures above approximately 300 MeV.

  16. Corrosion Fatigue Behavior of 316LN SS in Acidified Sodium Chloride Solution at Applied Potential

    Science.gov (United States)

    Poonguzhali, A.; Pujar, M. G.; Mallika, C.; Mudali, U. Kamachi

    2015-05-01

    The influence of acidified 1 M NaCl solution by addition of 2 ml/L of HCl on the cyclic plastic deformation of AISI Type 316LN SS containing 0.07 wt.% and 0.22 wt.% N was investigated as a function of the applied potentials. The corrosion fatigue (CF) behavior of stainless steel (SS) was explained vis-a-vis the dislocation behavior, the propensity to form microcracks, and the evolution of the current transients based on the studies carried out at both room-temperature and boiling conditions. CF experiments were conducted using round tensile specimens at a stress ratio of 0.5 and a frequency of 0.1 Hz. Two different kinds of damage mechanisms were observed (I) the damage mechanism in the stable-passive state was correlated with the localization of the anodic dissolution due to a depassivation-repassivation process, whereas (II) the cyclic stress induced pitting corrosion in the metastable pitting state, which resulted in formation of microcracks. The study of the microcracking process and its evolution is a key to the physical mechanism by which the fatigue life of stainless steels would be affected in an aqueous corrosive solution under the applied potential.

  17. Simulating sunflower canopy temperatures to infer root-zone soil water potential

    Science.gov (United States)

    Choudhury, B. J.; Idso, S. B.

    1983-01-01

    A soil-plant-atmosphere model for sunflower (Helianthus annuus L.), together with clear sky weather data for several days, is used to study the relationship between canopy temperature and root-zone soil water potential. Considering the empirical dependence of stomatal resistance on insolation, air temperature and leaf water potential, a continuity equation for water flux in the soil-plant-atmosphere system is solved for the leaf water potential. The transpirational flux is calculated using Monteith's combination equation, while the canopy temperature is calculated from the energy balance equation. The simulation shows that, at high soil water potentials, canopy temperature is determined primarily by air and dew point temperatures. These results agree with an empirically derived linear regression equation relating canopy-air temperature differential to air vapor pressure deficit. The model predictions of leaf water potential are also in agreement with observations, indicating that measurements of canopy temperature together with a knowledge of air and dew point temperatures can provide a reliable estimate of the root-zone soil water potential.

  18. Effect of temperature gradient on heavy quark anti-quark potential using gravity dual model

    CERN Document Server

    Ganesh, S

    2016-01-01

    The Quark-gluon plasma (QGP) is an expanding fireball, with finite dimensions. Given the finite dimensions, the temperature would be highest at the center, and close to the critical temperature, $T_c$, at the boundary, giving rise to a temperature gradient inside the QGP. A heavy quark anti-quark pair immersed in the QGP medium would see this temperature gradient. The effect of the temperature gradient on the quark anti-quark potential is analyzed using a gravity dual model. The resulting modification to the potential due to the temperature gradient is seen to have a $L^{-2}$ correction term. This could be a possible fallout of the breaking of conformal invariance at finite temperature.

  19. Critical temperature of Bose-Einstein condensation for weakly interacting bose gas in a potential trap

    Institute of Scientific and Technical Information of China (English)

    YU; Xuecai; YE; Yutang; WU; Yunfeng; XIE; Kang; CHENG; Lin

    2005-01-01

    The critical temperature of Bose-Einstein condensation at minimum momentum state for weakly interacting Bose gases in a power-law potential and the deviation of the critical temperature from ideal bose gas are studied. The effect of interaction on the critical temperature is ascribed to the ratiao α/λc, where α is the scattering length for s wave and λc is de Broglie wavelength at critical temperature. As α/λc<<1/(2π)2, the interaction is negligible. The presented deviation of the critical temperature for three dimensional harmonic potential is well in agreement with recent measurement of critical temperature for 87Rb bose gas trapped in a harmonic well.

  20. Two-loop dimensional reduction and effective potential without temperature expansions

    OpenAIRE

    M. Laine; Losada, M.

    2000-01-01

    In many extensions of the Standard Model, finite temperature computations are complicated by a hierarchy of zero temperature mass scales, in addition to the usual thermal mass scales. We extend the standard thermal resummations to such a situation, and discuss the 2-loop computations of the Higgs effective potential, and an effective 3d field theory for the electroweak phase transition, without carrying out high or low temperature expansions for the heavy masses. We also estimate the accuracy...

  1. Climate change impact of livestock CH4 emission in India: Global temperature change potential (GTP) and surface temperature response.

    Science.gov (United States)

    Kumari, Shilpi; Hiloidhari, Moonmoon; Kumari, Nisha; Naik, S N; Dahiya, R P

    2017-09-12

    Two climate metrics, Global surface Temperature Change Potential (GTP) and the Absolute GTP (AGTP) are used for studying the global surface temperature impact of CH4 emission from livestock in India. The impact on global surface temperature is estimated for 20 and 100 year time frames due to CH4 emission. The results show that the CH4 emission from livestock, worked out to 15.3 Tg in 2012. In terms of climate metrics GTP of livestock-related CH4 emission in India in 2012 were 1030 Tg CO2e (GTP20) and 62 Tg CO2e (GTP100) at the 20 and 100 year time horizon, respectively. The study also illustrates that livestock-related CH4 emissions in India can cause a surface temperature increase of up to 0.7mK and 0.036mK over the 20 and 100 year time periods, respectively. The surface temperature response to a year of Indian livestock emission peaks at 0.9mK in the year 2021 (9 years after the time of emission). The AGTP gives important information in terms of temperature change due to annual CH4 emissions, which is useful when comparing policies that address multiple gases. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Osmotic potential calculations of inorganic and organic aqueous solutions over wide solute concentration levels and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Cochrane, T. T., E-mail: agteca@hotmail.com [AGTECA S.A., 230 Oceanbeach Road, Mount Maunganui, Tauranga 3116 (New Zealand); Cochrane, T. A., E-mail: tom.cochrane@canterbury.ac.nz [Department of Civil and Natural Resources Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand)

    2016-01-15

    Purpose: To demonstrate that the authors’ new “aqueous solution vs pure water” equation to calculate osmotic potential may be used to calculate the osmotic potentials of inorganic and organic aqueous solutions over wide ranges of solute concentrations and temperatures. Currently, the osmotic potentials of solutions used for medical purposes are calculated from equations based on the thermodynamics of the gas laws which are only accurate at low temperature and solute concentration levels. Some solutions used in medicine may need their osmotic potentials calculated more accurately to take into account solute concentrations and temperatures. Methods: The authors experimented with their new equation for calculating the osmotic potentials of inorganic and organic aqueous solutions up to and beyond body temperatures by adjusting three of its factors; (a) the volume property of pure water, (b) the number of “free” water molecules per unit volume of solution, “N{sub f},” and (c) the “t” factor expressing the cooperative structural relaxation time of pure water at given temperatures. Adequate information on the volume property of pure water at different temperatures is available in the literature. However, as little information on the relative densities of inorganic and organic solutions, respectively, at varying temperatures needed to calculate N{sub f} was available, provisional equations were formulated to approximate values. Those values together with tentative t values for different temperatures chosen from values calculated by different workers were substituted into the authors’ equation to demonstrate how osmotic potentials could be estimated over temperatures up to and beyond bodily temperatures. Results: The provisional equations formulated to calculate N{sub f}, the number of free water molecules per unit volume of inorganic and organic solute solutions, respectively, over wide concentration ranges compared well with the calculations of N{sub f

  3. Rocket-borne measurements of electron temperature and density with the Electron Retarding Potential Analyzer instrument

    Science.gov (United States)

    Cohen, I. J.; Widholm, M.; Lessard, M. R.; Riley, P.; Heavisides, J.; Moen, J. I.; Clausen, L. B. N.; Bekkeng, T. A.

    2016-07-01

    Determining electron temperature in the ionosphere is a fundamentally important measurement for space science. Obtaining measurements of electron temperatures at high altitudes (>700 km) is difficult because of limitations on ground-based radar and classic spacecraft instrumentation. In light of these limitations, the rocket-borne Electron Retarding Potential Analyzer (ERPA) was developed to allow for accurate in situ measurement of ionospheric electron temperature with a simple and low-resource instrument. The compact ERPA, a traditional retarding potential analyzer with multiple baffle collimators, allows for a straightforward calculation of electron temperature. Since its first mission in 2004, it has amassed significant flight heritage and obtained data used in multiple studies investigating a myriad of phenomena related to magnetosphere-ionosphere coupling. In addition to highlighting the scientific contributions of the ERPA instrument, this paper outlines its theory and operation, the methodology used to obtain electron temperature measurements, and a comparative study suggesting that the ERPA can also provide electron density measurements.

  4. Heat distribution function for motion in a general potential at low temperature

    DEFF Research Database (Denmark)

    Fogedby, Hans; Imparato, Alberto

    2009-01-01

    We consider the 1D motion of an over-damped Brownian particle in a general potential in the low temperature limit. We derive an explicit expression for the probability distribution for the heat transferred to the particle. We find that the local minima in the potential yield divergent side bands...

  5. Three-loop HTLpt thermodynamics at finite temperature and isospin chemical potential

    CERN Document Server

    Andersen, Jens O; Mustafa, Munshi G; Strickland, Michael

    2015-01-01

    In a previous paper (JHEP {\\bf 05} (2014) 27), we calculated the three-loop thermodynamic potential of QCD at finite temperature $T$ and quark chemical potentials $\\mu_q$ using the hard-thermal-loop perturbation theory (HTLpt) reorganization of finite temperature and density QCD. The result allows us to study the thermodynamics of QCD at finite temperature and isospin chemical potential $\\mu_I$. We calculate the pressure, energy density, and entropy density, the trace anomaly, and the speed of sound at zero and nonzero $\\mu_I$. The second, fourth, and sixth-order isospin susceptibilities are calculated at zero $\\mu_I$. Our results can be directly compared to lattice QCD without Taylor expansions around $\\mu_q=0$ since QCD has no sign problem at finite isospin chemical potential.

  6. Potential for Extrinsic Incubation Temperature to Alter Interplay Between Transmission Potential and Mortality of Dengue-Infected Aedes aegypti

    Science.gov (United States)

    Christofferson, Rebecca C.; Mores, Christopher N.

    2016-01-01

    The extrinsic incubation period is a critical component in the assessment of arboviral transmission potential. It defines the time it takes for a mosquito to become infectious following exposure to an arbovirus. Since this is a temporal process, the lifespan of a mosquito is intimately tied to the extrinsic incubation period and thus transmission potential of these viruses. Temperature is a known effector of both vector competence (the ability of a vector to transmit a pathogen) and mosquito mortality, but the interaction among temperature, vector competence, and mosquito mortality is not well characterized. Herein, we investigate this interaction for dengue virus, serotype 2, and its primary vector Aedes aegypti where we found that at 30 °C, infection and/or dissemination shortened the average lifespan of the mosquito and that when considering only mosquitoes with a disseminated infection, those incubated at 26 °C lived significantly longer. PMID:27478382

  7. Two-loop dimensional reduction and effective potential without temperature expansions

    CERN Document Server

    Laine, Mikko

    2000-01-01

    In many extensions of the Standard Model, finite temperature computations are complicated by a hierarchy of zero temperature mass scales, in addition to the usual thermal mass scales. We extend the standard thermal resummations to such a situation, and discuss the 2-loop computations of the Higgs effective potential, and an effective 3d field theory for the electroweak phase transition, without carrying out high or low temperature expansions for the heavy masses. We also estimate the accuracy of the temperature expansions previously used for the MSSM electroweak phase transition in the presence of a heavy left-handed stop. We find that the low temperature limit of dealing with the left-handed stop is accurate up to surprisingly high temperatures.

  8. Evaluation of soil temperature effect on herbicide leaching potential into groundwater in the Brazilian Cerrado.

    Science.gov (United States)

    Paraíba, Lourival Costa; Cerdeira, Antonio Luiz; da Silva, Enio Fraga; Martins, João Souza; Coutinho, Heitor Luiz da Costa

    2003-12-01

    The effect of annual variations in the daily average soil temperatures, at different depths, on the calculation of pesticide leaching potential indices is presented. This index can be applied to assess the risk of groundwater contamination by a pesticide. It considers the effects of water table depth, daily recharge net rate, pesticide sorption coefficient, and degradation rate of the pesticide in the soil. The leaching potential index is frequently used as a screening indicator in pesticide groundwater contamination studies, and the temperature effect involved in its calculation is usually not considered. It is well known that soil temperature affects pesticide degradation rates, air-water partition coefficient, and water-soil partition coefficient. These three parameters are components of the attenuation and retardation factors, as well as the leaching potential index, and contribute to determine pesticide behavior in the environment. The Arrhenius, van't Hoff, and Clausius-Clapeyron equations were used in this work to estimate the soil temperature effect on pesticide degradation rate, air-water partition coefficient, and water-soil partition coefficient, respectively. The relationship between leaching potential index and soil temperature at different depths is presented and aids in the understanding of how potential pesticide groundwater contamination varies on different climatic conditions. Numerical results will be presented for 31 herbicides known to be used in corn and soybean crops grown on the municipality of São Gabriel do Oeste, Mato Grosso do Sul State, Brazil.

  9. Critical Temperature of Chiral Symmetry Restoration for Quark Matter with a Chiral Chemical Potential

    CERN Document Server

    Ruggieri, M

    2016-01-01

    In this article we study restoration of chiral symmetry at finite temperature for quark matter with a chiral chemical potential, $\\mu_5$, by means of a quark-meson model with vacuum fluctuations included. Vacuum fluctuations give a divergent contribution to the vacuum energy, so the latter has to be renormalized before computing physical quantities. The vacuum term is important for restoration of chiral symmetry at finite temperature and $\\mu_5\

  10. The pressure of deconfined QCD for all temperatures and quark chemical potentials

    CERN Document Server

    Ipp, A

    2007-01-01

    A new method for the evaluation of the perturbative expansion of the QCD pressure is presented which is valid for all temperatures and quark chemical potentials in the deconfined phase, and worked out up to and including order g^4. This new approach unifies several distinct perturbative approaches to the equation of state, and agrees with dimensional reduction, HDL and HTL resummation schemes, and the zero-temperature result in their respective ranges of validity.

  11. Temperature response of methane oxidation and production potentials in peatland ecosystems across Finland

    Science.gov (United States)

    Welti, Nina; Korrensalo, Aino; Kerttula, Johanna; Maljanen, Marja; Uljas, Salli; Lohila, Annalea; Laine, Anna; Vesala, Timo; Elliott, David; Tuittila, Eeva-Stiina

    2016-04-01

    It has been suggested that the ecosystems located in the high latitudes are especially sensitive to warming. Therefore, we compared 14 peatland systems throughout Finland along a latitudinal gradient from 69°N to 61°N to examine the response of methane production and methane oxidation with warming climate. Peat samples were taken at the height of the growing season in 2015 from 0 - 10cm below the water table depth. The plant communities in sampling locations were described by estimating cover of each plant species and pH of water was measured. Upon return to the lab, we made two parallel treatments, under anoxic and oxic conditions in order to calculate the CH4 production and consumption potentials of the peat and used three temperatures, 4°C, 17.5°C, and 30°C to examine the temperature effect on the potentials. We hypothesized that there will be an observable response curve in CH4 production and oxidation relative to temperature with a greater response with increasing latitude. In general, increasing temperature increased the potential for CH4 production and oxidation, at some sites, the potential was highest at 17.5°C, indicating that there is an optimum temperature threshold for the in situ methane producing and oxidizing microbial communities. Above this threshold, the peat microbial communities are not able to cope with increasing temperature. This is especially noticeable for methane oxidation at sites above 62°N. As countries are being expected to adequately account for their greenhouse gas budgets with increasing temperature models, knowing where the temperature threshold exists is of critical importance.

  12. Calculating the Finite-Tempuerature Effective Potential with the theory Renormalized at Zero-Temperature

    OpenAIRE

    1999-01-01

    In this paper we apply the renormalization-group (RG) inspired resummation method to the one-loop effective potential at finite temperature evaluated in the massive scalar 04 model renormalized at zero-temperature, and study whether ourresummation procedure a la RG uccessfully resum the dominant correction terms apperaed in the perturbative caluculation in the T = 0 renormalization scheme or not.Our findings are i) that if we start from the theory renormalized at T = 0, then the condition tha...

  13. Semiquantification of fibrillation potentials with intramuscular temperature drop using an animal model.

    OpenAIRE

    Lee, H. J.; Kwon, H. K.

    1997-01-01

    It has been reported that the quantity of fibrillation potentials (FP) decreases with drop in the intramuscular temperature. However, the quantitative measurement of the FP with intramuscular temperature changes has not been reported. Under anesthesia of intraperitoneal sodium pentobarbital, the sciatic nerve of 6 rats (Sprague-Dawley) was surgically isolated. A 1-cm segment was excised after tying the proximal and distal ends of the nerve segment. A concentric needle electrode and thermomete...

  14. Detection and Classification of Ozone Laminae Using Vertical Profiles of Ozone and Potential Temperature

    Science.gov (United States)

    Giljum, A. T., III; Minschwaner, K. R.; Manney, G. L.; Petropavlovskikh, I. V.

    2016-12-01

    We quantify ozone variability in the upper troposphere and lower stratosphere (UTLS) by analyzing lamination features in balloon measurements of ozone mixing ratio and potential temperature. Laminae are identified as sufficiently strong perturbations from basic state vertical profiles, which are derived on a case-by-case basis using smoothing methods applied within a vertical coordinate system relative to the WMO (temperature gradient) tropopause. The perturbations consistently show extensive lamination features in both ozone and potential temperature. We will describe methods that have been developed to minimize the contamination of lamina features by sharp changes in ozone and potential gradients near the tropopause. A laminae correlation technique is used to classify those particular features associated with gravity wave phenomena. We will present results of this analysis for the 25-year record of ozonesonde measurements from Boulder, Colorado, emphasizing the role of gravity waves on ozone variability in the UTLS region.

  15. Revisiting the definition of the electronic chemical potential, chemical hardness, and softness at finite temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Franco-Pérez, Marco, E-mail: qimfranco@hotmail.com, E-mail: jlgm@xanum.uam.mx [Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, México D. F. 09340 (Mexico); Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Gázquez, José L., E-mail: qimfranco@hotmail.com, E-mail: jlgm@xanum.uam.mx [Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, México D. F. 09340 (Mexico); Ayers, Paul W. [Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Vela, Alberto [Departamento de Química, Centro de Investigación y de Estudios Avanzados (Cinvestav), Av. Instituto Politécnico Nacional 2508, México D. F. 07360 (Mexico)

    2015-10-21

    We extend the definition of the electronic chemical potential (μ{sub e}) and chemical hardness (η{sub e}) to finite temperatures by considering a reactive chemical species as a true open system to the exchange of electrons, working exclusively within the framework of the grand canonical ensemble. As in the zero temperature derivation of these descriptors, the response of a chemical reagent to electron-transfer is determined by the response of the (average) electronic energy of the system, and not by intrinsic thermodynamic properties like the chemical potential of the electron-reservoir which is, in general, different from the electronic chemical potential, μ{sub e}. Although the dependence of the electronic energy on electron number qualitatively resembles the piecewise-continuous straight-line profile for low electronic temperatures (up to ca. 5000 K), the introduction of the temperature as a free variable smoothens this profile, so that derivatives (of all orders) of the average electronic energy with respect to the average electron number exist and can be evaluated analytically. Assuming a three-state ensemble, well-known results for the electronic chemical potential at negative (−I), positive (−A), and zero values of the fractional charge (−(I + A)/2) are recovered. Similarly, in the zero temperature limit, the chemical hardness is formally expressed as a Dirac delta function in the particle number and satisfies the well-known reciprocity relation with the global softness.

  16. Local chemical potential, local hardness, and dual descriptors in temperature dependent chemical reactivity theory.

    Science.gov (United States)

    Franco-Pérez, Marco; Ayers, Paul W; Gázquez, José L; Vela, Alberto

    2017-05-31

    In this work we establish a new temperature dependent procedure within the grand canonical ensemble, to avoid the Dirac delta function exhibited by some of the second order chemical reactivity descriptors based on density functional theory, at a temperature of 0 K. Through the definition of a local chemical potential designed to integrate to the global temperature dependent electronic chemical potential, the local chemical hardness is expressed in terms of the derivative of this local chemical potential with respect to the average number of electrons. For the three-ground-states ensemble model, this local hardness contains a term that is equal to the one intuitively proposed by Meneses, Tiznado, Contreras and Fuentealba, which integrates to the global hardness given by the difference in the first ionization potential, I, and the electron affinity, A, at any temperature. However, in the present approach one finds an additional temperature-dependent term that introduces changes at the local level and integrates to zero. Additionally, a τ-hard dual descriptor and a τ-soft dual descriptor given in terms of the product of the global hardness and the global softness multiplied by the dual descriptor, respectively, are derived. Since all these reactivity indices are given by expressions composed of terms that correspond to products of the global properties multiplied by the electrophilic or nucleophilic Fukui functions, they may be useful for studying and comparing equivalent sites in different chemical environments.

  17. Improving demand response potential of a supermarket refrigeration system: A food temperature estimation approach

    DEFF Research Database (Denmark)

    Pedersen, Rasmus; Schwensen, John; Biegel, Benjamin

    2017-01-01

    a method for estimating food temperature based on measurements of evaporator expansion valve opening degree. This method requires no additional hardware or system modeling. We demonstrate the estimation method on a real supermarket display case and the applicability of knowing food temperature is shown...... through tests on a full scale supermarket refrigeration system made available by Danfoss A/S. The conducted application test shows that feedback based on food temperature can increase the demand flexibility during a step by approx. 60 % the first 70 minutes and up to 100%over the first 150 minutes...... - thereby strengthening the demand response potential of supermarket refrigeration systems....

  18. Potential hydrothermal resource temperatures in the Eastern Snake River Plain, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Ghanashayam Neupane; Earl D. Mattson; Cody J. Cannon; Trevor A. Atkinson; Travis L. McLing; Thomas R. Wood; Patrick F. Dobson; Mark E. Conrad

    2016-02-01

    The Eastern Snake River Plain (ESRP) in southern Idaho is a region of high heat flow. Sustained volcanic activities in the wake of the passage of the Yellowstone Hotspot have turned this region into an area with great potential for geothermal resources as evidenced by numerous hot springs scattered along the margins of the plain and several hot-water producing wells and hot springs within the plain. Despite these thermal expressions, it is hypothesized that the pervasive presence of an overlying groundwater aquifer in the region effectively masks thermal signatures of deep-seated geothermal resources. The dilution of deeper thermal water and re-equilibration at lower temperature are significant challenges for the evaluation of potential resource areas in the ESRP. Over the past several years, we collected approximately 100 water samples from springs/wells for chemical analysis as well as assembled existing water chemistry data from literature. We applied several geothermometric and geochemical modeling tools to these chemical compositions of ESRP water samples. Geothermometric calculations based on principles of multicomponent equilibrium geothermometry with inverse geochemical modeling capability (e.g., Reservoir Temperature Estimator, RTEst) have been useful for the evaluation of reservoir temperatures. RTEst geothermometric calculations of ESRP thermal water samples indicated numerous potential geothermal areas with elevated reservoir temperatures. Specifically, areas around southern/southwestern side of the Bennett Hills and within the Camas Prairies in the western-northwestern regions of the ESRP and its margins suggest temperatures in the range of 140-200°C. In the northeastern portions of the ESRP, Lidy Hot Springs, Ashton, Newdale, and areas east of Idaho Falls have expected reservoir temperature =140 °C. In the southern ERSP, areas near Buhl and Twin Falls are found to have elevated temperatures as high as 160 °C. These areas are likely to host

  19. Three loop HTL perturbation theory at finite temperature and chemical potential

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, Michael [Department of Physics, Kent State University, Kent, OH 44242 (United States); Andersen, Jens O. [Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim (Norway); Bandyopadhyay, Aritra; Haque, Najmul; Mustafa, Munshi G. [Theory Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Su, Nan [Faculty of Physics, University of Bielefeld, D-33615 Bielefeld (Germany)

    2014-11-15

    In this proceedings contribution we present a recent three-loop hard-thermal-loop perturbation theory (HTLpt) calculation of the thermodynamic potential for a finite temperature and chemical potential system of quarks and gluons. We compare the resulting pressure, trace anomaly, and diagonal/off-diagonal quark susceptibilities with lattice data. We show that there is good agreement between the three-loop HTLpt analytic result and available lattice data.

  20. Three loop HTL perturbation theory at finite temperature and chemical potential

    CERN Document Server

    Strickland, Michael; Bandyopadhyay, Aritra; Haque, Najmul; Mustafa, Munshi G; Su, Nan

    2014-01-01

    In this proceedings contribution we present a recent three-loop hard-thermal-loop perturbation theory (HTLpt) calculation of the thermodynamic potential for a finite temperature and chemical potential system of quarks and gluons. We compare the resulting pressure, trace anomaly, and diagonal/off-diagonal quark susceptibilities with lattice data. We show that there is good agreement between the three-loop HTLpt analytic result and available lattice data.

  1. Potential High-Temperature Shape-Memory Alloys Identified in the Ti(Ni,Pt) System

    Science.gov (United States)

    Noebe, Ronald D.; Biles, Tiffany A.; Garg, Anita; Nathal, Michael V.

    2004-01-01

    "Shape memory" is a unique property of certain alloys that, when deformed (within certain strain limits) at low temperatures, will remember and recover to their original predeformed shape upon heating. It occurs when an alloy is deformed in the low-temperature martensitic phase and is then heated above its transformation temperature back to an austenitic state. As the material passes through this solid-state phase transformation on heating, it also recovers its original shape. This behavior is widely exploited, near room temperature, in commercially available NiTi alloys for connectors, couplings, valves, actuators, stents, and other medical and dental devices. In addition, there are limitless applications in the aerospace, automotive, chemical processing, and many other industries for materials that exhibit this type of shape-memory behavior at higher temperatures. But for high temperatures, there are currently no commercial shape-memory alloys. Although there are significant challenges to the development of high-temperature shape-memory alloys, at the NASA Glenn Research Center we have identified a series of alloy compositions in the Ti-Ni-Pt system that show great promise as potential high-temperature shape-memory materials.

  2. Ascertaining the potential effects of temperature on growth, survival and feeding of different juvenile clown fish

    Directory of Open Access Journals (Sweden)

    Vishwas Rao Methari

    2015-02-01

    Full Text Available Objective: To determine the physiological and ecological responses of marine ornamental fishes to the change of water temperature with its potential effects on the growth, survival and feeding in clown fish. Methods: Three different sea anemone fish (Premnas biaculeatus, Amphiprion clarkii, Amphiprion akallopisos were reared in confinement at water temperatures of 26, 28, 30, 32, and 34 °C using thermostat and they were maintained up to the marketable size, and growth, survival and feeding were evaluated during the experimental period. Results: The results illustrated that water temperature influenced the physiological performance of juveniles of three different sea anemone fish significantly. The growth and survival rates of juveniles of three different clown fish significantly increased with the increase of water temperature from 26 °C to 34 °C (P<0.05. Water temperature also influenced the feeding of three different clown fish significantly with feed conversion ratio increased from (0.071±0.020, (0.075±0.030 and (0.079±0.028 to (0.057±0.040, (0.047±0.030 and (0.045±0.028 for Premnas biaculeatus, Amphiprion clarkii and Amphiprion akallopisos respectively with increase of water temperature from 26 °C to 34 °C (P<0.05. Specific growth rates (P<0.05 increased significantly with increase of water temperature and positively correlated with the feed conversion ratio, indicating that growth rates are significantly increased with increase of temperature. Conclusions: This study deliberately reveals that the physiological response of juveniles of clown fish as the change of water temperature and substantiated that water temperature influenced juvenile growth, survival and feeding significantly. This study also put forward that the reduced growth, survival and feeding of juveniles at lower temperature which have ecological impacts on clown fish juveniles in settlement and population replacement in the wild.

  3. Effect of foam on temperature prediction and heat recovery potential from biological wastewater treatment.

    Science.gov (United States)

    Corbala-Robles, L; Volcke, E I P; Samijn, A; Ronsse, F; Pieters, J G

    2016-05-15

    Heat is an important resource in wastewater treatment plants (WWTPs) which can be recovered. A prerequisite to determine the theoretical heat recovery potential is an accurate heat balance model for temperature prediction. The insulating effect of foam present on the basin surface and its influence on temperature prediction were assessed in this study. Experiments were carried out to characterize the foam layer and its insulating properties. A refined dynamic temperature prediction model, taking into account the effect of foam, was set up. Simulation studies for a WWTP treating highly concentrated (manure) wastewater revealed that the foam layer had a significant effect on temperature prediction (3.8 ± 0.7 K over the year) and thus on the theoretical heat recovery potential (30% reduction when foam is not considered). Seasonal effects on the individual heat losses and heat gains were assessed. Additionally, the effects of the critical basin temperature above which heat is recovered, foam thickness, surface evaporation rate reduction and the non-absorbed solar radiation on the theoretical heat recovery potential were evaluated.

  4. The calculation of quark number susceptibility at finite chemical potential and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Yu; Li Ning [Department of Physics, Nanjing University, Nanjing 210093 (China); Sun Weimin [Department of Physics, Nanjing University, Nanjing 210093 (China); Joint Center for Particle, Nuclear Physics and Cosmology, Nanjing 210093 (China); Zong Hongshi, E-mail: zonghs@chenwang.nju.edu.c [Department of Physics, Nanjing University, Nanjing 210093 (China); Joint Center for Particle, Nuclear Physics and Cosmology, Nanjing 210093 (China)

    2010-03-01

    In this paper, we calculate the quark number susceptibility (QNS) at finite chemical potential mu and finite temperature T in the framework of the Dyson-Schwinger approach using the meromorphic quark propagator proposed in [Phys. Rev. D 70, 014014 (2004)]. Analysis and discussions of the calculated result of the QNS is given.

  5. Interpretation of fast measurements of plasma potential, temperature and density in SOL of ASDEX Upgrade

    DEFF Research Database (Denmark)

    Horacek, J.; Adamek, J.; Müller, H.W.

    2010-01-01

    This paper focuses on interpretation of fast (1 µs) and local (2–4 mm) measurements of plasma density, potential and electron temperature in the edge plasma of tokamak ASDEX Upgrade. Steady-state radial profiles demonstrate the credibility of the ball-pen probe. We demonstrate that floating poten...

  6. Temperature-derived potential for the establishment of phlebotomine sandflies and visceral leishmaniasis in Germany.

    Science.gov (United States)

    Fischer, Dominik; Thomas, Stephanie M; Beierkuhnlein, Carl

    2010-11-01

    Climate change is expected to manifest in the shift of organisms to regions where they were not present in the past, potentially entailing previously unseen biological risks. However, studies evaluating these future trends are scarce. Here, an important group of vectors (sandflies) and the pathogen transmitted (Leishmania infantum complex) causing the infectious disease visceral leishmaniasis is investigated, focussing on potential establishment in Germany during the 21st century. As the most important habitat factor, temperature requirements of pathogen and vector were derived from the literature and compared with recent climate records - provided by worldclim - and climate change scenarios. Climate data from the Regional Climate Model REMO were obtained and averaged over the time periods 2011- 2040, 2041-2070 and 2071-2100. Projected temperature changes (based on the A1B and A2 scenarios) were correlated with the constraints of vector and pathogen. Simulated potentially suitable habitat areas for vector and pathogen were merged to generate a temperature-derived risk map of visceral leishmaniasis. Temperature conditions seem to become suitable for the vector across large swaths of Germany. Nevertheless, temperature constraints for the pathogen may defer the establishment of the parasitic disease, particularly during the first half of the 21st century. Long-lasting epidemics of visceral leishmaniasis are therefore not expected in Germany during the next few decades, although during extremely warm years an increase in autochthonous cases of leishmaniasis may occur. The southwest (Upper Rhine Valley) and west (Cologne Bight) of Germany are identified as risk areas. The time of potential establishment and corresponding rise in biological risk varies between scenarios, due to differences in the predicted rate of temperature increase.

  7. Temperature-derived potential for the establishment of phlebotomine sandflies and visceral leishmaniasis in Germany

    Directory of Open Access Journals (Sweden)

    Dominik Fischer

    2010-11-01

    Full Text Available Climate change is expected to manifest in the shift of organisms to regions where they were not present in the past, potentially entailing previously unseen biological risks. However, studies evaluating these future trends are scarce. Here, an important group of vectors (sandflies and the pathogen transmitted (Leishmania infantum complex causing the infectious disease visceral leishmaniasis is investigated, focussing on potential establishment in Germany during the 21st century. As the most important habitat factor, temperature requirements of pathogen and vector were derived from the literature and compared with recent climate records - provided by worldclim - and climate change scenarios. Climate data from the Regional Climate Model REMO were obtained and averaged over the time periods 2011- 2040, 2041-2070 and 2071-2100. Projected temperature changes (based on the A1B and A2 scenarios were correlated with the constraints of vector and pathogen. Simulated potentially suitable habitat areas for vector and pathogen were merged to generate a temperature-derived risk map of visceral leishmaniasis. Temperature conditions seem to become suitable for the vector across large swaths of Germany. Nevertheless, temperature constraints for the pathogen may defer the establishment of the parasitic disease, particularly during the first half of the 21st century. Long-lasting epidemics of visceral leishmaniasis are therefore not expected in Germany during the next few decades, although during extremely warm years an increase in autochthonous cases of leishmaniasis may occur. The southwest (Upper Rhine Valley and west (Cologne Bight of Germany are identified as risk areas. The time of potential establishment and corresponding rise in biological risk varies between scenarios, due to differences in the predicted rate of temperature increase.

  8. Ascertaining the potential effects of temperature on growth, survival and feeding of different juvenile clown ifsh

    Institute of Scientific and Technical Information of China (English)

    Vishwas Rao Methari; Mohideen Abdul Badhul Haq; Chinna Raja; Sheik Mohamed

    2015-01-01

    Objective:To determine the physiological and ecological responses of marine ornamental fishes to the change of water temperature with its potential effects on the growth, survival and feeding in clown fish. Methods: Three different sea anemone fish (Premnas biaculeatus, Amphiprion clarkii, Amphiprion akallopisos) were reared in confinement at water temperatures of 26, 28, 30, 32, and 34 oC using thermostat and they were maintained up to the marketable size, and growth, survival and feeding were evaluated during the experimental period. Results: The results illustrated that water temperature influenced the physiological performance of juveniles of three different sea anemone fish significantly. The growth and survival rates of juveniles of three different clown fish significantly increased with the increase of water temperature from 26 oC to 34 oC (P Conclusions:This study deliberately reveals that the physiological response of juveniles of clown fish as the change of water temperature and substantiated that water temperature influenced juvenile growth, survival and feeding significantly. This study also put forward that the reduced growth, survival and feeding of juveniles at lower temperature which have ecological impacts on clown fish juveniles in settlement and population replacement in the wild.

  9. Adaptation potential of naturally ventilated barns to high temperature extremes: The OptiBarn project

    Science.gov (United States)

    Menz, Christoph

    2016-04-01

    Climate change interferes with various aspects of the socio-economic system. One important aspect is its influence on animal husbandry, especially dairy faming. Dairy cows are usually kept in naturally ventilated barns (NVBs) which are particular vulnerable to extreme events due to their low adaptation capabilities. An effective adaptation to high outdoor temperatures for example, is only possible under certain wind and humidity conditions. High temperature extremes are expected to increase in number and strength under climate change. To assess the impact of this change on NVBs and dairy cows also the changes in wind and humidity needs to be considered. Hence we need to consider the multivariate structure of future temperature extremes. The OptiBarn project aims to develop sustainable adaptation strategies for dairy housings under climate change for Europe, by considering the multivariate structure of high temperature extremes. In a first step we identify various multivariate high temperature extremes for three core regions in Europe. With respect to dairy cows in NVBs we will focus on the wind and humidity field during high temperature events. In a second step we will use the CORDEX-EUR-11 ensemble to evaluate the capability of the RCMs to model such events and assess their future change potential. By transferring the outdoor conditions to indoor climate and animal wellbeing the results of this assessment can be used to develop technical, architectural and animal specific adaptation strategies for high temperature extremes.

  10. Germination of Winter Annual Grass Weeds under a Range of Temperatures and Water Potentials

    DEFF Research Database (Denmark)

    Scherner, Ananda; Melander, Bo; Jensen, Peter Kryger

    2017-01-01

    Silky windgrass and annual bluegrass are among the most troublesome weeds in northern European winter crops, while problems with rattail fescue have been especially linked to direct-drilling practices. This study investigated the germination patterns of silky windgrass, annual bluegrass, and ratt......Silky windgrass and annual bluegrass are among the most troublesome weeds in northern European winter crops, while problems with rattail fescue have been especially linked to direct-drilling practices. This study investigated the germination patterns of silky windgrass, annual bluegrass......, and rattail fescue in multiple water potentials and temperature regimes. Temperature and water potential effects were similar between silky windgrass and rattail fescue, but differed from annual bluegrass. The three grass weeds were able to germinate under low water potential (−1.0 MPa), although water...

  11. Temperature and voltage coupling to channel opening in transient receptor potential melastatin 8 (TRPM8).

    Science.gov (United States)

    Raddatz, Natalia; Castillo, Juan P; Gonzalez, Carlos; Alvarez, Osvaldo; Latorre, Ramon

    2014-12-19

    Expressed in somatosensory neurons of the dorsal root and trigeminal ganglion, the transient receptor potential melastatin 8 (TRPM8) channel is a Ca(2+)-permeable cation channel activated by cold, voltage, phosphatidylinositol 4,5-bisphosphate, and menthol. Although TRPM8 channel gating has been characterized at the single channel and macroscopic current levels, there is currently no consensus regarding the extent to which temperature and voltage sensors couple to the conduction gate. In this study, we extended the range of voltages where TRPM8-induced ionic currents were measured and made careful measurements of the maximum open probability the channel can attain at different temperatures by means of fluctuation analysis. The first direct measurements of TRPM8 channel temperature-driven conformational rearrangements provided here suggest that temperature alone is able to open the channel and that the opening reaction is voltage-independent. Voltage is a partial activator of TRPM8 channels, because absolute open probability values measured with fully activated voltage sensors are less than 1, and they decrease as temperature rises. By unveiling the fast temperature-dependent deactivation process, we show that TRPM8 channel deactivation is well described by a double exponential time course. The fast and slow deactivation processes are temperature-dependent with enthalpy changes of 27.2 and 30.8 kcal mol(-1). The overall Q10 for the closing reaction is about 33. A three-tiered allosteric model containing four voltage sensors and four temperature sensors can account for the complex deactivation kinetics and coupling between voltage and temperature sensor activation and channel opening.

  12. Global and regional temperature-change potentials for near-term climate forcers

    Directory of Open Access Journals (Sweden)

    W. J. Collins

    2013-03-01

    Full Text Available We examine the climate effects of the emissions of near-term climate forcers (NTCFs from 4 continental regions (East Asia, Europe, North America and South Asia using results from the Task Force on Hemispheric Transport of Air Pollution Source-Receptor global chemical transport model simulations. We address 3 aerosol species (sulphate, particulate organic matter and black carbon and 4 ozone precursors (methane, reactive nitrogen oxides (NOx, volatile organic compounds and carbon monoxide. We calculate the global climate metrics: global warming potentials (GWPs and global temperature change potentials (GTPs. For the aerosols these metrics are simply time-dependent scalings of the equilibrium radiative forcings. The GTPs decrease more rapidly with time than the GWPs. The aerosol forcings and hence climate metrics have only a modest dependence on emission region. The metrics for ozone precursors include the effects on the methane lifetime. The impacts via methane are particularly important for the 20 yr GTPs. Emissions of NOx and VOCs from South Asia have GWPs and GTPs of higher magnitude than from the other Northern Hemisphere regions. The analysis is further extended by examining the temperature-change impacts in 4 latitude bands, and calculating absolute regional temperature-change potentials (ARTPs. The latitudinal pattern of the temperature response does not directly follow the pattern of the diagnosed radiative forcing. We find that temperatures in the Arctic latitudes appear to be particularly sensitive to BC emissions from South Asia. The northern mid-latitude temperature response to northern mid-latitude emissions is approximately twice as large as the global average response for aerosol emission, and about 20–30% larger than the global average for methane, VOC and CO emissions.

  13. Global and Regional Temperature-change Potentials for Near-term Climate Forcers

    Science.gov (United States)

    Collins, W.J.; Fry, M.M.; Yu, H.; Fuglestvedt, J. S.; Shindell, D. T.; West, J. J.

    2013-01-01

    We examine the climate effects of the emissions of near-term climate forcers (NTCFs) from 4 continental regions (East Asia, Europe, North America and South Asia) using results from the Task Force on Hemispheric Transport of Air Pollution Source-Receptor global chemical transport model simulations. We address 3 aerosol species (sulphate, particulate organic matter and black carbon) and 4 ozone precursors (methane, reactive nitrogen oxides (NOx), volatile organic compounds and carbon monoxide). We calculate the global climate metrics: global warming potentials (GWPs) and global temperature change potentials (GTPs). For the aerosols these metrics are simply time-dependent scalings of the equilibrium radiative forcings. The GTPs decrease more rapidly with time than the GWPs. The aerosol forcings and hence climate metrics have only a modest dependence on emission region. The metrics for ozone precursors include the effects on the methane lifetime. The impacts via methane are particularly important for the 20 yr GTPs. Emissions of NOx and VOCs from South Asia have GWPs and GTPs of higher magnitude than from the other Northern Hemisphere regions. The analysis is further extended by examining the temperature-change impacts in 4 latitude bands, and calculating absolute regional temperature-change potentials (ARTPs). The latitudinal pattern of the temperature response does not directly follow the pattern of the diagnosed radiative forcing. We find that temperatures in the Arctic latitudes appear to be particularly sensitive to BC emissions from South Asia. The northern mid-latitude temperature response to northern mid-latitude emissions is approximately twice as large as the global average response for aerosol emission, and about 20-30% larger than the global average for methane, VOC and CO emissions.

  14. Binding Energy Calculation of Electrons in Statistical Potentials for Arbitrary Temperature and Matter Density

    Institute of Scientific and Technical Information of China (English)

    SunYongsheng; MengXujun

    1990-01-01

    Schroedinger's wave equation is solved in Thomas-Fermi potential including the self-interaction modification of elctrons for arbitrary matter density and temperature,In order to describe relativistic effects,the mass-velocity correction,the Darwin correction and the spin-orbit coupling terms are included in the wave equation.Calculations are presented for the Fe26 and Rb37 atoms at a few temperatures and matter densities.Comparisons of present results with other more accurate one[9] are given in Table.The data obtained by the present method are not bad.

  15. Stability curve prediction of homologous proteins using temperature-dependent statistical potentials.

    Directory of Open Access Journals (Sweden)

    Fabrizio Pucci

    2014-07-01

    Full Text Available The unraveling and control of protein stability at different temperatures is a fundamental problem in biophysics that is substantially far from being quantitatively and accurately solved, as it requires a precise knowledge of the temperature dependence of amino acid interactions. In this paper we attempt to gain insight into the thermal stability of proteins by designing a tool to predict the full stability curve as a function of the temperature for a set of 45 proteins belonging to 11 homologous families, given their sequence and structure, as well as the melting temperature (Tm and the change in heat capacity (ΔCP of proteins belonging to the same family. Stability curves constitute a fundamental instrument to analyze in detail the thermal stability and its relation to the thermodynamic stability, and to estimate the enthalpic and entropic contributions to the folding free energy. In summary, our approach for predicting the protein stability curves relies on temperature-dependent statistical potentials derived from three datasets of protein structures with targeted thermal stability properties. Using these potentials, the folding free energies (ΔG at three different temperatures were computed for each protein. The Gibbs-Helmholtz equation was then used to predict the protein's stability curve as the curve that best fits these three points. The results are quite encouraging: the standard deviations between the experimental and predicted Tm's, ΔCP's and folding free energies at room temperature (ΔG25 are equal to 13° C, 1.3 kcal/(mol° C and 4.1 kcal/mol, respectively, in cross-validation. The main sources of error and some further improvements and perspectives are briefly discussed.

  16. Lifespan metabolic potential of the unicellular organisms expressed by Boltzmann constant, absolute temperature and proton mass

    Science.gov (United States)

    Atanasov, Atanas Todorov

    2016-12-01

    The unicellular organisms and phages are the first appeared fundamental living organisms on the Earth. The total metabolic energy (Els, J) of these organisms can be expressed by their lifespan metabolic potential (Als, J/kg) and body mass (M, kg): Els =Als M. In this study we found a different expression - by Boltzmann's constant (k, J/K), nucleon mass (mp+, kg) of protons (and neutrons), body mass (M, kg) of organism or mass (Ms) of biomolecules (proteins, nucleotides, polysaccharides and lipids) building organism, and the absolute temperature (T, K). The found equations are: Els= (M/mp+)kT for phages and Els=(Ms/mp+)kT for the unicellular organisms. From these equations the lifespan metabolic potential can be expressed as: Als=Els/M= (k/mp+)T for phages and Als=Els/M= (k/3.3mp+)T for unicellular organisms. The temperature-normated lifespan metabolic potential (Als/T, J/K.kg) is equals to the ratio between Boltzmann's constant and nucleon mass: Als/T=k/mp+ for phages and Als/T=k/3.3mp+ for unicellular organisms. The numerical value of the k/mp+ ratio is equals to 8.254×103 J/K.kg, and the numerical value of k/3.3mp+ ratio is equal to 2.497×103 J/K.kg. These values of temperature-normated lifespan metabolic potential could be considered fundamental for the unicellular organisms.

  17. Local adaptation and evolutionary potential along a temperature gradient in the fungal pathogen Rhynchosporium commune

    Science.gov (United States)

    Stefansson, Tryggvi S; McDonald, Bruce A; Willi, Yvonne

    2013-01-01

    To predict the response of plant pathogens to climate warming, data are needed on current thermal adaptation, the pathogen's evolutionary potential, and the link between them. We conducted a common garden experiment using isolates of the fungal pathogen Rhynchosporium commune from nine barley populations representing climatically diverse locations. Clonal replicates of 126 genetically distinct isolates were assessed for their growth rate at 12°C, 18°C, and 22°C. Populations originating from climates with higher monthly temperature variation had higher growth rate at all three temperatures compared with populations from climates with less temperature fluctuation. Population differentiation in growth rate (QST) was significantly higher at 22°C than population differentiation for neutral microsatellite loci (GST), consistent with local adaptation for growth at higher temperatures. At 18°C, we found evidence for stabilizing selection for growth rate as QST was significantly lower than GST. Heritability of growth rate under the three temperatures was substantial in all populations (0.58–0.76). Genetic variation was lower in populations with higher growth rate at the three temperatures and evolvability increased under heat stress in seven of nine populations. Our findings imply that the distribution of this pathogen is unlikely to be genetically limited under climate warming, due to its high genetic variation and plasticity for thermal tolerance. PMID:23745143

  18. Evaluation of low-temperature geothermal potential in Cache Valley, Utah. Report of investigation No. 174

    Energy Technology Data Exchange (ETDEWEB)

    de Vries, J.L.

    1982-11-01

    Field work consisted of locating 90 wells and springs throughout the study area, collecting water samples for later laboratory analyses, and field measurement of pH, temperature, bicarbonate alkalinity, and electrical conductivity. Na/sup +/, K/sup +/, Ca/sup +2/, Mg/sup +2/, SiO/sub 2/, Fe, SO/sub 4//sup -2/, Cl/sup -/, F/sup -/, and total dissolved solids were determined in the laboratory. Temperature profiles were measured in 12 additional, unused walls. Thermal gradients calculated from the profiles were approximately the same as the average for the Basin and Range province, about 35/sup 0/C/km. One well produced a gradient of 297/sup 0/C/km, most probably as a result of a near-surface occurrence of warm water. Possible warm water reservoir temperatures were calculated using both the silica and the Na-K-Ca geothermometers, with the results averaging about 50 to 100/sup 0/C. If mixing calculations were applied, taking into account the temperatures and silica contents of both warm springs or wells and the cold groundwater, reservoir temperatures up to about 200/sup 0/C were indicated. Considering measured surface water temperatures, calculated reservoir temperatures, thermal gradients, and the local geology, most of the Cache Valley, Utah area is unsuited for geothermal development. However, the areas of North Logan, Benson, and Trenton were found to have anomalously warm groundwater in comparison to the background temperature of 13.0/sup 0/C for the study area. The warm water has potential for isolated energy development but is not warm enough for major commercial development.

  19. Heavy Quark Potential at Finite Temperature in a Dual Gravity Closer to Large N QCD

    CERN Document Server

    Patra, Binoy Krishna

    2014-01-01

    In gauge-gravity duality, heavy quark potential at finite temperature is usually calculated with the pure AdS background, which does not capture the renormalisation group (RG) running in the gauge theory part and the potential also does not contain any confining term in the deconfined phase. Following the developments in \\cite{KS}, a geometry was contructed recently in \\cite{ Mia:NPB2010, Mia:PRD2010}, which captures the RG flow similar to QCD and we employ their geometry to obtain the heavy quark potential by analytically continuing the string configurations into the complex plane. In addition to the attractive terms, the obtained potential has confining terms both at $T=0$ and $T \

  20. Potential for use of high-temperature superconductors in fusion reactors

    Science.gov (United States)

    Hull, John R.

    1992-09-01

    The present rate of development of high-temperature superconductors (HTSs) is sufficiently rapid that there may be opportunities for their use in contemporary fusion devices such as the International Thermonuclear Experimental Reactor (ITER). The most likely application is for delivering power to the superconducting magnets, especially in substituting for the current leads between the temperatures of 4 and 77 K. A second possible application of HTSs is in a liquid-nitrogen-cooled power bus connecting the power supplies to the magnets, thus reducing ohmic heating losses in these relatively long cables. A third potential application of HTSs is in inner high-field windings of the toroidal field coils that would operate at ~ 20 K. While the use of higher temperature magnets offers significant advantages to the reactor system, it is unlikely that tested HTSs for this application will be available within the ITER time frame.

  1. Quark-Number Susceptibility at Finite Chemical Potential and Zero Temperature

    Institute of Scientific and Technical Information of China (English)

    HE Deng-Ke; JIANG Yu; FENG Hong-Tao; SUN Wei-Min; ZONG Hong-Shi

    2008-01-01

    We give a direct method for calculating the quark-number susceptibility at finite chemical potential and zero temperature.In this approach the quark-number susceptibility is totally determined by G[μ](p)(the dressed quark propagator at finite chemical potential μ).By applying the general result in our previous study[Phys.Rev.C 71(2005)015205,034901,73 (2006) 016004] G[μ](p)is calculated from the model quark propagator proposed by Pagels and Stokar[Phys.Rev.D 20(1979)2947].The full analytic expression of the quark-number susceptibility at finite μ and zero T is obtained.

  2. Electromagnetic Acoustic Transducers Applied to High Temperature Plates for Potential Use in the Solar Thermal Industry

    Directory of Open Access Journals (Sweden)

    Maria Kogia

    2015-12-01

    Full Text Available Concentrated Solar Plants (CSPs are used in solar thermal industry for collecting and converting sunlight into electricity. Parabolic trough CSPs are the most widely used type of CSP and an absorber tube is an essential part of them. The hostile operating environment of the absorber tubes, such as high temperatures (400–550 °C, contraction/expansion, and vibrations, may lead them to suffer from creep, thermo-mechanical fatigue, and hot corrosion. Hence, their condition monitoring is of crucial importance and a very challenging task as well. Electromagnetic Acoustic Transducers (EMATs are a promising, non-contact technology of transducers that has the potential to be used for the inspection of large structures at high temperatures by exciting Guided Waves. In this paper, a study regarding the potential use of EMATs in this application and their performance at high temperature is presented. A Periodic Permanent Magnet (PPM EMAT with a racetrack coil, designed to excite Shear Horizontal waves (SH0, has been theoretically and experimentally evaluated at both room and high temperatures.

  3. QCD effective potential with strong magnetic fields at zero and finite temperatures

    Science.gov (United States)

    Ozaki, Sho; Arai, Takashi; Hattori, Koichi; Itakura, Kazunori

    2014-09-01

    In this contribution, we will discuss QCD vacuum in strong magnetic fields. As a first step towards understanding the effects of magnetic fields on QCD vacuum properties, we analytically derive the Euler-Heisenberg action for QCD + QED at zero and finite temperatures. From the action, at zero temperature, we found that the chromo-magnetic field prefers to be parallel to the external magnetic field, and thus the QCD vacuum with strong magnetic fields is spatially anisotropic. This result is consistent with recent lattice data. Furthermore, the chromo-magnetic condensate increases with an increasing magnetic field, which supports the ``gluonic magnetic catalysis'' as observed in current lattice data. Next, we will discuss the effective potential with strong magnetic fields at finite temperatures. In particular, we focus on the influence of the magnetic field on the center symmetry in QCD. The pure Yang-Mills theory has the center symmetry (being spontaneously broken at high temperature), but dynamical quarks explicitly break it. We will show how the magnetic fields affect the explicit symmetry breaking, by using the effective potential for the Polyakov loop. We will also discuss the confinement-deconfinement phase transition in strong magnetic fields in terms of nonperturbative approaches such as functional renormalization group.

  4. Electrodynamics at non-zero temperature, chemical potential and Bose condensate

    Energy Technology Data Exchange (ETDEWEB)

    Dolgov, Alexander D.; Lepidi, Angela [Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Polo Scientifico e Tecnologico, Via Saragat 1 (edificio C), 44100 Ferrara (Italy); Piccinelli, Gabriella, E-mail: dolgov@fe.infn.it, E-mail: lepidi@fe.infn.it, E-mail: gabriela@astroscu.unam.mx [Centro Tecnologico, FES Aragon, Universidad Nacional Autonoma de Mexico, Avenida Rancho Seco S/N, Bosques de Aragon, Nezahualcoyotl, Estado de Mexico 57130 (Mexico)

    2009-02-15

    Electrodynamics of charged scalar bosons and spin 1/2 fermions is studied at non-zero temperature, chemical potentials, and possible Bose condensate of the charged scalars. Debye screening length, plasma frequency, and the photon dispersion relation are calculated. It is found that in presence of the condensate the time-time component of the photon polarization operator in the first order in electric charge squared acquires infrared singular parts proportional to inverse powers of the spatial photon momentum k.

  5. Self-potential, soil co2 flux, and temperature on masaya volcano, nicaragua

    Energy Technology Data Exchange (ETDEWEB)

    Lewicki, J.L.; Connor, C.; St-Amand, K.; Stix, J.; Spinner, W.

    2003-07-01

    We investigate the spatial relationship between self-potential (SP), soil CO{sub 2} flux, and temperature and the mechanisms that produce SP anomalies on the flanks of Masaya volcano, Nicaragua. We measured SP, soil CO{sub 2} fluxes (<1 to 5.0 x 10{sup 4} g m{sup -2} d{sup -1}), and temperatures (26 to 80 C) within an area surrounding a normal fault, adjacent to Comalito cinder cone (2002-2003). These variables are well spatially correlated. Wavelengths of SP anomalies are {le}100 m, and high horizontal SP gradients flank the region of elevated flux and temperature. Carbon isotopic compositions of soil CO{sub 2} ({delta}{sup 13}C = -3.3 to -1.1{per_thousand}) indicate a deep gas origin. Given the presence of a deep water table (100 to 150 m), high gas flow rates, and subsurface temperatures above liquid boiling points, we suggest that rapid fluid disruption is primarily responsible for positive SP anomalies here. Concurrent measurement of SP, soil CO{sub 2} flux, and temperature may be a useful tool to monitor intrusive activity.

  6. Potential decline in geothermal energy generation due to rising temperatures under climate change scenarios

    Science.gov (United States)

    Angel, E.; Ortega, S.; Gonzalez-Duque, D.; Ruiz-Carrascal, D.

    2016-12-01

    Geothermal energy production depends on the difference between air temperature and the geothermal fluid temperature. The latter remains approximately constant over time, so the power generation varies according to local atmospheric conditions. Projected changes in near-surface air temperatures in the upper levels of the tropical belt are likely to exceed the projected temperature anomalies across many other latitudes, which implies that geothermal plants located in these regions may be affected, reducing their energy output. This study focuses on a hypothetical geothermal power plant, located in the headwaters of the Claro River watershed, a key high-altitude basin in Los Nevados Natural Park, on the El Ruiz-Tolima volcanic massif, in the Colombian Central Andes, a region with a known geothermal potential. Four different Atmospheric General Circulation Models where used to project temperature anomalies for the 2040-2069 prospective period. Their simulation outputs were merged in a differentially-weighted multi-model ensemble, whose weighting factors were defined according to the capability of individual models to reproduce ground truth data from a set of digital data-loggers installed in the basin since 2008 and from weather stations gathering climatic variables since the early 50s. Projected anomalies were computed for each of the Representative Concentration Pathways defined by the IPCC Fifth Assessment Report in the studied region. These climate change projections indicate that air temperatures will likely reach positive anomalies in the range +1.27 ºC to +3.47 ºC, with a mean value of +2.18 ºC. Under these conditions, the annual energy output declines roughly 1% per each degree of increase in near-surface temperature. These results must be taken into account in geothermal project evaluations in the region.

  7. New equations for density, entropy, heat capacity, and potential temperature of a saline thermal fluid

    Science.gov (United States)

    Sun, Hongbing; Feistel, Rainer; Koch, Manfred; Markoe, Andrew

    2008-10-01

    A set of fitted polynomial equations for calculating the physical variables density, entropy, heat capacity and potential temperature of a thermal saline fluid for a temperature range of 0-374 °C, pressure range of 0.1-100 MPa and absolute salinity range of 0-40 g/kg is established. The freshwater components of the equations are extracted from the recently released tabulated data of freshwater properties of Wagner and Pruß [2002. The IAPWS formulation 1995 for the thermodynamic properties of ordinary water substance for general and scientific use. Journal of Physical and Chemical Reference Data 31, 387-535]. The salt water component of the equation is based on the near-linear relationship between density, salinity and specific heat capacity and is extracted from the data sets of Feistel [2003. A new extended Gibbs thermodynamic potential of seawater. Progress in Oceanography 58, 43-114], Bromley et al. [1970. Heat capacities and enthalpies of sea salt solutions to 200 °C. Journal of Chemical and Engineering Data 15, 246-253] and Grunberg [1970. Properties of sea water concentrates. In: Third International Symposium on Fresh Water from the Sea, vol. 1, pp. 31-39] in a temperature range 0-200 °C, practical salinity range 0-40, and varying pressure and is also calibrated by the data set of Millero et al. [1981. Summary of data treatment for the international high pressure equation of state for seawater. UNESCO Technical Papers in Marine Science 38, 99-192]. The freshwater and salt water components are combined to establish a workable multi-polynomial equation, whose coefficients were computed through standard linear regression analysis. The results obtained in this way for density, entropy and potential temperature are comparable with those of existing models, except that our new equations cover a wider temperature—(0-374 °C) than the traditional (0-40 °C) temperature range. One can apply these newly established equations to the calculation of in-situ or

  8. Low-Temperature Biodiesel Research Reveals Potential Key to Successful Blend Performance (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-02-01

    Relatively low-cost solutions could improve reliability while making biodiesel blends an affordable option. While biodiesel has very low production costs and the potential to displace up to 10% of petroleum diesel, until now, issues with cold weather performance have prevented biodiesel blends from being widely adopted. Some biodiesel blends have exhibited unexplained low-temperature performance problems even at blend levels as low as 2% by volume. The most common low-temperature performance issue is vehicle stalling caused by fuel filter clogging, which prevents fuel from reaching the engine. Research at the National Renewable Energy Laboratory (NREL) reveals the properties responsible for these problems, clearing a path for the development of solutions and expanded use of energy-conserving and low-emissions alternative fuel. NREL researchers set out to study the unpredictable nature of biodiesel crystallization, the condition that impedes the flow of fuel in cold weather. Their research revealed for the first time that saturated monoglyceride impurities common to the biodiesel manufacturing process create crystals that can cause fuel filter clogging and other problems when cooling at slow rates. Biodiesel low-temperature operational problems are commonly referred to as 'precipitates above the cloud point (CP).' NREL's Advanced Biofuels team spiked distilled soy and animal fat-derived B100, as well as B20, B10, and B5 biodiesel blends with three saturated monoglycerides (SMGs) at concentration levels comparable to those of real-world fuels. Above a threshold or eutectic concentration, the SMGs (monomyristin, monopalmitin, and monostearin) were shown to significantly raise the biodiesel CP, and had an even greater impact on the final melting temperature. Researchers discovered that upon cooling, monoglyceride initially precipitates as a metastable crystal, but it transforms over time or upon slight heating into a more stable crystal with a much lower

  9. Selection of measures for a potential with two maxima at the zero temperature limit

    CERN Document Server

    Baraviera, Alexandre T; Lopes, Artur O

    2010-01-01

    For the subshift of finite type $\\S=\\{0,1,2\\}^{\\N}$ we study the convergence at temperature zero of the Gibbs measure associated to a non-locally constant H\\"older potential which admits only two maximizing measures. These measures are Dirac measures at two different fixed points. The potential is flattest at one of these two fixed points. The question we are interested is: which of these probabilities the invariant Gibbs state will select when temperature goes to zero? We prove that on the one hand the Gibbs measure converges, and at the other hand it does not necessarily converge to the measures where the potential is the flattest. We consider a family of potentials of the above form; for some of them there is the selection of a convex combination of the two Dirac measures, and for others there is a selection of the Dirac measure associated to the flattest point. In the first case this is contrary to what was expected if we consider the analogous problem in Aubry-Mather theory by N. Anantharaman, R. Iturria...

  10. Structure and stability of pyrophyllite edge surfaces: Effect of temperature and water chemical potential

    Science.gov (United States)

    Kwon, Kideok D.; Newton, Aric G.

    2016-10-01

    The surfaces of clay minerals, which are abundant in atmospheric mineral dust, serve as an important medium to catalyze ice nucleation. The lateral edge surface of 2:1 clay minerals is postulated to be a potential site for ice nucleation. However, experimental investigations of the edge surface structure itself have been limited compared to the basal planes of clay minerals. Density functional theory (DFT) computational studies have provided insights into the pyrophyllite edge surface. Pyrophyllite is an ideal surrogate mineral for the edge surfaces of 2:1 clay minerals as it possesses no or little structural charge. Of the two most-common hydrated edge surfaces, the AC edge, (1 1 0) surface in the monoclinic polytype notation, is predicted to be more stable than the B edge, (0 1 0) surface. These stabilities, however, were determined based on the total energies calculated at 0 K and did not consider environmental effects such as temperature and humidity. In this study, atomistic thermodynamics based on periodic DFT electronic calculations was applied to examine the effects of environmental variables on the structure and thermodynamic stability of the common edge surfaces in equilibrium with bulk pyrophyllite and water vapor. We demonstrate that the temperature-dependent vibrational energy of sorbed water molecules at the edge surface is a significant component of the surface free energy and cannot be neglected when determining the surface stability of pyrophyllite. The surface free energies were calculated as a function of temperature from 240 to 600 K and water chemical potential corresponding to conditions from ultrahigh vacuum to the saturation vapor pressure of water. We show that at lower water chemical potentials (dry conditions), the AC and B edge surfaces possessed similar stabilities; at higher chemical potentials (humid conditions) the AC edge surface was more stable than the B edge surface. At high temperatures, both surfaces showed similar stabilities

  11. S-parameter at Non-Zero Temperature and Chemical Potential

    CERN Document Server

    Søndergaard, Ulrik Ishøj; Sannino, Francesco

    2011-01-01

    We compute the finite-temperature and matter density corrections to the S-parameter at the one loop level. At non-zero temperature T and matter density Lorentz symmetry breaks and therefore we suggest a suitable generalization of the S-parameter. By computing the plasma correction, we discover a reduction of the S-parameter in the physically relevant region of small external momenta for any non-zero chemical potential and T. In particular, the S-parameter vanishes at small m/T, where m is the mass of the fermions, due to the finite extent of the temporal direction. Our results are directly applicable to the determination of the S-parameter via first principle lattice simulations performed with anti-periodic boundary conditions in the temporal direction.

  12. Natural thermoluminescence of fossil foraminiferals as a potential proxy for deep-sea temperature changes

    Institute of Scientific and Technical Information of China (English)

    LIU Haisheng; FANG Nianqiao; HOU Shengli; CHEN Yexun

    2008-01-01

    Foraminiferal shells from two piston cores separately located at the Ninetyeast Ridge and the Bengal Fan of the Indian Ocean were selected and purified for measurements of natural thermoluminescence (NTL) intensity by a high precision thermoluminescence meter ( RGD-3 ).Variations of the NTL intensity along the two core sequences both spanning the last two glacial-interglacial cycles displayed a strong,identical signal of the global ice volume cycles,which matched well with their corresponding oxygen isotope data.As higher NTL intensity occurred within interglacial periods and changes in an NTL signal were most likely influ-enced by the temperature of ambient seawater in which the planktonic foraminiferal shells long existed,the NTL signal could be considered as a potential proxy for orbital scale temperature changes of bottom seawater in the tropical Indian Ocean.

  13. Anharmonic effective pair potentials of gold under high pressure and high temperature

    CERN Document Server

    Okube, M; Ohtaka, O; Fukui, H; Katayama, Y; Utsumi, W

    2002-01-01

    In order to examine the effect of pressure on the anharmonicity of Au, extended x-ray absorption fine-structure spectra near the Au L sub 3 edge were measured in the temperature range from 300 to 1100 K under pressures up to 14 GPa using large-volume high-pressure devices and synchrotron radiation. The anharmonic effective pair potentials of Au, V (u) = au sup 2 + bu sup 3 , at 0.1 MPa, 6 and 14 GPa have been calculated. The pressure dependence of the thermal expansion coefficients has also been evaluated. The reliability of the anharmonic correction proposed on the basis of the Anderson scale has been discussed.

  14. Potential of low-temperature geothermal resources in northern California. Report No. TR13

    Energy Technology Data Exchange (ETDEWEB)

    Hannah, J.L.

    1975-01-01

    Economically feasible uses for geothermal heat at temperatures too low for conventional electrical power generation at present are delineated. Several geothermal resource areas in northern California that have development potential are described, and applications of the heat found in each area are suggested. Plates are included of the following field study areas: the east side of the Sierra-Cascade Range north of Bishop, and the northern Coast Range from San Francisco Bay to Clear Lake. The counties included in the study area are Mo doc, Lassen, Sierra, Plumas, Placer, Alpine, Mono, Mendocino, Lake, and Sonoma. (LBS)

  15. Temperature derivative of the chemical potential and its magnetooscillations in two-dimensional system

    OpenAIRE

    Tupikov, Y.; Kuntsevich, A. Yu.; Pudalov, V. M.; Burmistrov, I. S.

    2015-01-01

    We report first thermodynamic measurements of the temperature derivative of chemical potential (d{\\mu}/dT) in two-dimensional (2D) electron systems. In order to test the technique we have chosen Schottky gated GaAs/AlGaAs heterojunctions and detected experimentally in this 2D system quantum magnetooscillations of d{\\mu}/dT. We also present a Lifshits-Kosevitch type theory for the d{\\mu}/dT magnetooscillations in 2D systems and compare the theory with experimental data. The magnetic field depe...

  16. The Two-Loop Finite-Temperature Effective Potential of the MSSM and Baryogenesis

    CERN Document Server

    Losada, M

    1999-01-01

    We construct an effective three dimensional theory for the MSSM at high temperatures in the limit of large-$m_{A}$. We analyse the two-loop effective potential of the 3D theory for the case of a light right handed stop to determine the precise region in the $m_{h}$-$m_{\\tilde{t}_{R}}$ plane for which the sphaleron constraint for preservation of the baryon asymmetry is satisfied. We also compare with results previously obtained usind 3D and 4D calculations of the effective potential. A two-stage phase transition still persists for a small range of values of $m_{\\tilde{t}_{R}}$. The allowed region requires a value of $m_{\\tilde{t}_{R}} \\lsi m_{t}$ and $m_{h} \\lsi 100$ (110) GeV for $m_{Q} = 300$ GeV (1 TeV).

  17. Investigating aftergrowth potential of polymers in drinking water – the effect of water replacement and temperature

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Albrechtsen, Hans-Jørgen

    no significant effect on the aftergrowth potential of the water. The background biomass production could be affected by the choice of caps for the test bottles, since ‘blue caps’ of polyethylene leached significant amounts of AOCP17 compared to ‘red caps’ containing teflon inlayers. There was no or only slightly......The aftergrowth potential of polymers used in drinking water distribution was investigated by a batch set-up, where test pieces were incubated in biostable, inorganic nutrient amended drinking water inoculated with surface water. Biomass production was measured as ATP and followed over 16 weeks...... in the water phase and on the material surface. Supplementary measurements of HPC and NVOC were applied when investigating the biostability within the test system, and the effect of water replacement and temperature. Addition of inorganic nutrients and inoculum to the biostable drinking water had...

  18. Effect of temperature on energy potential of pyrolysis products from oil palm shells

    Directory of Open Access Journals (Sweden)

    Lina María Romero Millán

    2016-06-01

    Full Text Available Context: Taking into account that near 220 000 tons of oil palm shells are produced every year in Colombia, as a waste of the Elaeis Guineensis palm oil transformation process, the aim of this work is to determine the energy potential of oil palm shells, when transformed through slow pyrolysis process.Methods: Using a fixed bed lab scale reactor, different oil palm shells pyrolysis tests were performed between 300°C and 500°C. The effect of the temperature in the process product yield and in the energy content of produced solids and gases were analyzed.Results: With a maximum mass yield of 50%, the char is considered the main product of oil palm shells pyrolysis, containing up to 73% of the raw biomass energy. The heating value of char raised with the temperature, from 29,6 MJ/kg at 300°C to 31,34 MJ/kg at 500°C. Moreover, the gas produced in the established temperature range had up to 13% of the energy content of the raw biomass, with a heating value near 12,5 MJ/m3.Conclusions: According to the results, slow pyrolysis can be considered an interesting process for the valorization of residual biomass as oil palm shells, through the production of solids and gases that can be used as fuels, or as precursor of other value-added products.

  19. Potential association of dengue hemorrhagic fever incidence and remote senses land surface temperature, Thailand, 1998.

    Science.gov (United States)

    Nitatpattana, Narong; Singhasivanon, Pratap; Kiyoshi, Honda; Andrianasolo, Haja; Yoksan, Sutee; Gonzalez, Jean-Paul; Barbazan, Philippe

    2007-05-01

    A pilot study was designed to analyze a potential association between dengue hemorrhagic fever (DHF) incidence and, temperature computed by satellite. DHF is a mosquito transmitted disease, and water vapor and humidity are known to have a positive effect on mosquito life by increasing survival time and shortening the development cycle. Among other available satellite data, Land Surface Temperature (LST) was chosen as an indicator that combined radiated earth temperature and atmospheric water vapor concentration. Monthly DHF incidence was recorded by province during the 1998 epidemic and obtained as a weekly combined report available from the National Ministry of Public Health. Conversely, LST was calculated using remotely sensed data obtained from thermal infrared sensors of NOAA satellites and computed on a provincial scale. Out of nine selected study provinces, five (58.3%) exhibited an LST with a significant positive correlation with rainfall (p < 0.05). In four out of nineteen surveyed provinces (21.3%), LST showed a significant positive correlation with DHF incidence (p < 0.05). Positive association between LST and DHF incidence was significantly correlated in 75% of the cases during non-epidemic months, while no correlation was found during epidemic months. Non-climatic factors are supposed to be at the origin of this discrepancy between seasonality in climate (LST) and DHF incidence during epidemics.

  20. An Improved Method for Establishing Accurate Water Potential Levels at Different Temperatures in Growth Media

    Directory of Open Access Journals (Sweden)

    Iqbal S. Aujla

    2017-08-01

    Full Text Available NaCl, KCl, or PEG (polyethylene glycol-amended potato dextrose broth (PDB, and potato dextrose agar (PDA are essential for pure culture studies of water stress on fungi. Direct information on the actual water potential (WP of this salt-amended PDB and PDA is lacking. Much fungal research in the past calculated WP of these salt-amended growth media by adding the WP of their constituents taken from individual salt dilution studies. But the WP of any complex solution will be modified by the level of synergism between its solutes. This study presents evidence of change in NaCl concentration due to synergism for attaining the same level of WP in NaCl solution, and NaCl amended PDB and PDA. The relation between WP and temperature and WP and salt concentration is also modified depending on the number of solutes in a growth medium. The WP of PEG-amended PDB increases with rising temperature, while that of NaCl/KCl amended PDB and PDA decreases with the increase of temperature. These results can be useful for doing pure culture studies on the biology and modeling the growth of air, water, and soil-borne fungi important in the food and agriculture industry and in terrestrial and aquatic ecosystems.

  1. Potential of thermoluminescence method to estimate the time-temperature condition of fault activity

    Science.gov (United States)

    Hasebe, N.; Miura, K.; Ganzawa, Y.

    2016-12-01

    To date the last fault activity by a radiometric dating method, the resetting of dating system, that is a function of time-temperature condition, is inevitable. To see whether a particular dating system was reset by fault activities, we often estimate a temperature rise by frictional heating under the geophysical and geological observations of stress field and displacement length. When the last fault activity occurred beyond the observation era, such attempt is difficult to apply with little knowledge on what happened in the past. Luminescence dating method (TL and OSL datings) has a potential to date the last event of active fault in Quaternary (e.g., Spencer et al., 2012, Ganzawa et al., 2013), for it is easily reset compared to other dating methods with higher closure temperatures over geological time scale. However, if a sample experienced only a partial resetting in luminescence dating system, the obtained ages do not correspond to any events. We propose the potential of thermoluminescence method to estimate the time-temperature condition of the fault-related sample. Thermoluminescence glow curve consists of signals from several traps (e.g., Spooner, et al., 2001). Lifetime (τ) of each trap is calculated from the following equation (Aitken, 1985). τ=s-1exp(E/kT), where s is the frequency factor (/sec), E is trap depth (eV), k is Boltzmann constant (eV/K), and T is temperature (K). When luminescence signal is decreased by the event from I0 to Im, the time (t) necessary for this decrease is estimated by the equation t=τln(I0/Im). If we have two trap sites in a sample, and I0 can be estimated somehow (e.g., from the signal intensity of unaffected higher trap), two unknowns (t and T) can be determined from two sets of equations. In general, signals will be regained after the event owing to annual dose rate and time passed since the event. Therefore present signal intensity (Ip) is described as equation Ip=Ix+Im ,where Ix is the signal built after the event

  2. Influence of the Applied Potential and Temperature on the Electrodeposition of the Lead Dioxide

    Directory of Open Access Journals (Sweden)

    Taha Yaseen Khalaf

    2013-06-01

    Full Text Available The excellent specifications of electrodes coated with lead dioxide material make it of great importance in the industry. So it was suggested this study, which includes electrodeposition of lead dioxide on graphite substrate, knowing that the electrodeposition of lead dioxide on graphite studied earlier in different ways. In this work the deposition process for lead dioxide conducted using electrolytic solution containing lead nitrate concentration 0.72 M with the addition of some other material to the solution, such as copper nitrate, nickel nitrate, sodium fluoride and cetyl trimethyl ammonium bromide, but only in very small concentrations. As for the operating conditions, the effect of change potential and temperature as well as the time on the deposition process was studied. The results shown at the end of the experiments that the change in the applied potential to the cell and electrolytic solution temperature had the greatest influence on the cell current, anodic current density, anodic overpotential and the amount of lead dioxide deposited on the anode.

  3. Mantle potential temperature estimates of basalt from the surface of Venus

    Science.gov (United States)

    Shellnutt, J. Gregory

    2016-10-01

    The crater density and distribution of Venus indicates the average surface age is younger (≤1 Ga) than most terrestrial planets and satellites in the Solar System. The type and rate (i.e. equilibrium, catastrophic or differential) of volcanism associated with the stagnant lid tectonic system of Venus is a first order problem that has yet to be resolved but is directly related to the thermal conditions of the mantle. The calculated primary melt composition of basalt at the Venera 14 landing site is high-Mg basalt to picrite with a mantle potential temperature estimate similar to terrestrial ambient mantle (1370 ± 70 °C). The calculated accumulated fractional melting curves indicate the olivine compositions from the melt have Mg# of 89-91. The results show that the thermal regime required to generate the primary melt composition of the Venera 14 basalt was not anomalously high (i.e. mantle-plume system) but rather consistent with a lithospheric tensional rift system. The juxtaposition of high thermal regime structures (e.g. Beta Regio) and 'ambient' mantle potential temperature estimates of the Venera 14 basalt suggests that the relatively young surface of Venus is the result of volcanism from a combination of thermal systems that resurfaced the planet at variable rates.

  4. Thermodynamic properties of rhodium at high temperature and pressure by using mean field potential approach

    Science.gov (United States)

    Kumar, Priyank; Bhatt, Nisarg K.; Vyas, Pulastya R.; Gohel, Vinod B.

    2016-10-01

    The thermophysical properties of rhodium are studied up to melting temperature by incorporating anharmonic effects due to lattice ions and thermally excited electrons. In order to account anharmonic effects due to lattice vibrations, we have employed mean field potential (MFP) approach and for thermally excited electrons Mermin functional. The local form of the pseudopotential with only one effective adjustable parameter rc is used to construct MFP and hence vibrational free energy due to ions - Fion. We have studied equation of state at 300 K and further, to access the applicability of present conjunction scheme, we have also estimated shock-Hugoniot and temperature along principle Hugoniot. We have carried out the study of temperature variation of several thermophysical properties like thermal expansion (βP), enthalpy (EH), specific heats at constant pressure and volume (CP and CV), specific heats due to lattice ions and thermally excited electrons ( and , isothermal and adiabatic bulk moduli (BT and Bs) and thermodynamic Gruneisen parameter (γth) in order to examine the inclusion of anharmonic effects in the present study. The computed results are compared with available experimental results measured by using different methods and previously obtained theoretical results using different theoretical philosophy. Our computed results are in good agreement with experimental findings and for some physical quantities better or comparable with other theoretical results. We conclude that local form of the pseudopotential used accounts s-p-d hybridization properly and found to be transferable at extreme environment without changing the values of the parameter. Thus, even the behavior of transition metals having complexity in electronic structure can be well understood with local pseudopotential without any modification in the potential at extreme environment. Looking to the success of present scheme (MFP + pseudopotential) we would like to extend it further for the

  5. Global and Regional Temperature-change Potentials for Near-term Climate Forcers

    Science.gov (United States)

    Collins, W.J.; Fry, M. M.; Yu, H.; Fuglestvedt, J. S.; Shindell, D. T.; West, J. J.

    2013-01-01

    The emissions of reactive gases and aerosols can affect climate through the burdens of ozone, methane and aerosols, having both cooling and warming effects. These species are generally referred to near-term climate forcers (NTCFs) or short-lived climate pollutants (SLCPs), because of their short atmospheric residence time. The mitigation of these would be attractive for both air quality and climate on a 30-year timescale, provided it is not at the expense of CO2 mitigation. In this study we examine the climate effects of the emissions of NTCFs from 4 continental regions (East Asia, Europe, North America and South Asia) using results from the Task Force on Hemispheric Transport of Air Pollution Source-Receptor global chemical transport model simulations. We address 3 aerosol species (sulphate, particulate organic matter and black carbon - BC) and 4 ozone precursors (methane, reactive nitrogen oxides - NOx, volatile organic compounds VOC, and carbon monoxide - CO). For the aerosols the global warming potentials (GWPs) and global temperature change potentials (GTPs) are simply time-dependent scaling of the equilibrium radiative forcing, with the GTPs decreasing more rapidly with time than the GWPs. While the aerosol climate metrics have only a modest dependence on emission region, emissions of NOx and VOCs from South Asia have GWPs and GTPs of higher magnitude than from the other northern hemisphere regions. On regional basis, the northern mid-latitude temperature response to northern mid-latitude emissions is approximately twice as large as the global average response for aerosol emission, and about 20-30% larger than the global average for methane, VOC and CO emissions. We also found that temperatures in the Arctic latitudes appear to be particularly sensitive to black carbon emissions from South Asia.

  6. Potential impact of increased temperature and CO2 on particulate dimethylsulfoniopropionate in the Southeastern Bering Sea

    Directory of Open Access Journals (Sweden)

    Peter A. Lee

    2011-06-01

    Full Text Available The potential impact of elevated sea surface temperature (SST and pCO2 on algal community structure and particulate dimethylsulfoniopropionate (DMSPp concentrations in the southeastern Bering Sea was examined using a shipboard “Ecostat” continuous culture system. The ecostat system was used to mimic the conditions projected to exist in the world's oceans by the end of this century (i.e. elevated pCO2 (750 ppm and elevated SST (ambient + 4°C. Two experiments were conducted using natural phytoplankton assemblages from the high-nutrient low-chlorophyll (HNLC central basin and from the middle domain of the southeastern continental shelf. At the HNLC site, the relative abundances of haptophytes and pelagophytes were higher and the relative abundance of diatoms lower under “greenhouse” conditions (i.e. combined 750 ppm CO2 and elevated temperature than control conditions (380 ppm CO2 and ambient temperature. This shift in algal community structure was accompanied by increases in DMSPp (2–3 fold, DMSPp:Chl a (2–3 fold and DMSP:PON (2 fold. At the continental shelf site, the changes in the relative abundances of haptophytes, pelagophytes and diatoms under “greenhouse” conditions were similar to those observed at the HNLC site, with 2.5 fold increases in DMSPp, 50–100% increases in DMSPp:Chl a and 1.8 fold increases in DMSP:PON. At both locations, changes in community structure and the DMSPp parameters were largely driven by increasing temperature. The observed changes were also consistent with the phytoplankton-DMS-albedo climate feedback mechanism proposed in the Charlson-Lovelock-Andreae-Warren (CLAW hypothesis.

  7. Investigation of potential waste material insulating properties at different temperature for thermal storage application

    Science.gov (United States)

    Ali, T. Z. S.; Rosli, A. B.; Gan, L. M.; Billy, A. S.; Farid, Z.

    2013-12-01

    Thermal energy storage system (TES) is developed to extend the operation of power generation. TES system is a key component in a solar energy power generation plant, but the main issue in designing the TES system is its thermal capacity of storage materials, e.g. insulator. This study is focusing on the potential waste material acts as an insulator for thermal energy storage applications. As the insulator is used to absorb heat, it is needed to find suitable material for energy conversion and at the same time reduce the waste generation. Thus, a small-scale experimental testing of natural cooling process of an insulated tank within a confined room is conducted. The experiment is repeated by changing the insulator from the potential waste material and also by changing the heat transfer fluid (HTF). The analysis presented the relationship between heat loss and the reserved period by the insulator. The results show the percentage of period of the insulated tank withstands compared to tank insulated by foam, e.g. newspaper reserved the period of 84.6% as much as foam insulated tank to withstand the heat transfer of cooking oil to the surrounding. The paper finally justifies the most potential waste material as an insulator for different temperature range of heat transfer fluid.

  8. Regional potential evapotranspiration in arid climates based on temperature, topography and calculated solar radiation

    Science.gov (United States)

    Shevenell, Lisa

    1999-03-01

    Values of evapotranspiration are required for a variety of water planning activities in arid and semi-arid climates, yet data requirements are often large, and it is costly to obtain this information. This work presents a method where a few, readily available data (temperature, elevation) are required to estimate potential evapotranspiration (PET). A method using measured temperature and the calculated ratio of total to vertical radiation (after the work of Behnke and Maxey, 1969) to estimate monthly PET was applied for the months of April-October and compared with pan evaporation measurements. The test area used in this work was in Nevada, which has 124 weather stations that record sufficient amounts of temperature data. The calculated PET values were found to be well correlated (R2=0·940-0·983, slopes near 1·0) with mean monthly pan evaporation measurements at eight weather stations.In order to extrapolate these calculated PET values to areas without temperature measurements and to sites at differing elevations, the state was divided into five regions based on latitude, and linear regressions of PET versus elevation were calculated for each of these regions. These extrapolated PET values generally compare well with the pan evaporation measurements (R2=0·926-0·988, slopes near 1·0). The estimated values are generally somewhat lower than the pan measurements, in part because the effects of wind are not explicitly considered in the calculations, and near-freezing temperatures result in a calculated PET of zero at higher elevations in the spring months. The calculated PET values for April-October are 84-100% of the measured pan evaporation values. Using digital elevation models in a geographical information system, calculated values were adjusted for slope and aspect, and the data were used to construct a series of maps of monthly PET. The resultant maps show a realistic distribution of regional variations in PET throughout Nevada which inversely mimics

  9. A thermodynamic framework for understanding temperature sensing by transient receptor potential (TRP) channels.

    Science.gov (United States)

    Clapham, David E; Miller, Christopher

    2011-12-06

    The exceptionally high temperature sensitivity of certain transient receptor potential (TRP) family ion channels is the molecular basis of hot and cold sensation in sensory neurons. The laws of thermodynamics dictate that opening of these specialized TRP channels must involve an unusually large conformational standard-state enthalpy, ΔH(o): positive ΔH(o) for heat-activated and negative ΔH(o) for cold-activated TRPs. However, the molecular source of such high-enthalpy changes has eluded neurobiologists and biophysicists. Here we offer a general, unifying mechanism for both hot and cold activation that recalls long-appreciated principles of protein folding. We suggest that TRP channel gating is accompanied by large changes in molar heat capacity, ΔC(P). This postulate, along with the laws of thermodynamics and independent of mechanistic detail, leads to the conclusion that hot- and cold-sensing TRPs operate by identical conformational changes.

  10. Experimental study on the indoor temperature variation characteristics and energy conservation potentialities in winter

    Institute of Scientific and Technical Information of China (English)

    LONGEnshen; WANGYong; FUXiangzhao

    2003-01-01

    This paper conducts an experiment on the starting and stopping of an indoor air-conditioner in winter, and obtains a sedes of experimental data of the indoor environmental temperature. With these data, it makes a further calculation of the indoor PMV index during the start-up and shutdown of the air-conditioner. On condition that the human body''s thermal comfort is basically guaranteed, an optimal combination mode of time is worked out to start and stop the air conditioner that operates intermittently in the experimental room. If the starting and stopping of the air-conditioner is managed in this way, the maximum energy-saving potentiality can be 41% compared with the traditional continuous operation.

  11. The melting temperature of liquid water with the effective fragment potential

    Energy Technology Data Exchange (ETDEWEB)

    Brorsen, Kurt R.; Willow, Soohaeng Y.; Xantheas, Sotiris S.; Gordon, Mark S.

    2015-09-17

    Direct simulation of the solid-liquid water interface with the effective fragment potential (EFP) via the constant enthalpy and pressure (NPH) ensemble was used to estimate the melting temperature (Tm) of ice-Ih. Initial configurations and velocities, taken from equilibrated constant pressure and temperature (NPT) simulations at T = 300 K, 350 K and 400 K, respectively, yielded corresponding Tm values of 378±16 K, 382±14 K and 384±15 K. These estimates are consistently higher than experiment, albeit to the same degree with previously reported estimates using density functional theory (DFT)-based Born-Oppenheimer simulations with the Becke-Lee-Yang-Parr functional plus dispersion corrections (BLYP-D). KRB was supported by a Computational Science Graduate Fellowship from the Department of Energy. MSG was supported by a U.S. National Science Foundation Software Infrastructure (SI2) grant (ACI – 1047772). SSX acknowledges support from the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle.

  12. The integrated global temperature change potential (iGTP) and relationships between emission metrics

    Science.gov (United States)

    Peters, Glen P.; Aamaas, Borgar; Berntsen, Terje; Fuglestvedt, Jan S.

    2011-12-01

    The Kyoto Protocol compares greenhouse gas emissions (GHGs) using the global warming potential (GWP) with a 100 yr time-horizon. The GWP was developed, however, to illustrate the difficulties in comparing GHGs. In response, there have been many critiques of the GWP and several alternative emission metrics have been proposed. To date, there has been little focus on understanding the linkages between, and interpretations of, different emission metrics. We use an energy balance model to mathematically link the absolute GWP, absolute global temperature change potential (AGTP), absolute ocean heat perturbation (AOHP), and integrated AGTP. For pulse emissions, energy conservation requires that AOHP = AGWP - iAGTP/λ and hence AGWP and iAGTP are closely linked and converge as AOHP decays to zero. When normalizing the metrics with CO2 (GWP, GTP, and iGTP), we find that the iGTP and GWP are similar numerically for a wide range of GHGs and time-horizons, except for very short-lived species. The similarity between the iGTPX and GWPX depends on how well a pulse emission of CO2 can substitute for a pulse emission of X across a range of time-horizons. The ultimate choice of emission metric(s) and time-horizon(s) depends on policy objectives. To the extent that limiting integrated temperature change over a specific time-horizon is consistent with the broader objectives of climate policy, our analysis suggests that the GWP represents a relatively robust, transparent and policy-relevant emission metric.

  13. Li zoning in zircon as a potential geospeedometer and peak temperature indicator

    Science.gov (United States)

    Trail, Dustin; Cherniak, Daniele J.; Watson, E. Bruce; Harrison, T. Mark; Weiss, Benjamin P.; Szumila, Ian

    2016-03-01

    Zircon Li concentrations and δ7Li values may potentially trace crustal recycling because continental and mantle-derived zircons yield distinct values. The usefulness of these differences may depend upon the retentivity of zircon to Li concentrations and isotopic ratios. Given the relatively high Li diffusivities measured by Cherniak and Watson (Contrib Mineral Petrol 160: 383-390, 2010), we sought to discover the scenarios under which Li mobility might be inhibited by charge-compensating cations. Toward this end, we conducted "in" diffusion experiments in which Li depth profiles of synthetic Lu-doped, P-doped, and undoped zircon were determined by nuclear reaction analysis. In separate experiments, Li was ion-implanted at depth within polished natural zircon slabs to form a Gaussian Li concentration profile. Diffusively relaxed concentration profiles were measured after heating the slabs to determine diffusivities. In all experiments, which ranged from 920 to 650 °C, calculated diffusivities are in agreement with a previously established Arrhenius relationship calibrated on trace-element-poor Mud Tank zircon. Our revised Arrhenius relationship that includes both datasets is: D_{Li} = 9.60 × 10^{ - 7} exp [ {{ - 278 ± 8{{kJ}/{mol}^{ - 1} }}{RT}} ]{m}^{ 2} {{s}}^{ - 1} We also observed that synthetic sector-zoned zircon exhibits near-step-function Li concentration profiles across sectors that correlate with changes in the rare earth element (REE) and P concentrations. This allowed us to examine how Li diffusion might couple with REE diffusion in a manner different than that described above. In particular, re-heating these grains revealed significant Li migration, but no detectable migration of the rare earth elements. Thus, unlike most elements in zircon which are not mobile at the micrometer scale under most time-temperature paths in the crust, Li zoning, relaxation of zoning, or lack of zoning altogether could be used to reveal time-temperature information

  14. Hydrothermal system of the Papandayan Volcano from temperature, self-potential (SP) and geochemical measurements

    Science.gov (United States)

    Byrdina, Svetlana; Revil, André; Gunawan, Hendra; Saing, Ugan B.; Grandis, Hendra

    2017-07-01

    Papandayan volcano in West Java, Indonesia, is characterized by intense hydrothermal activities manifested by numerous fumaroles at three craters or kawah, i.e. Mas, Manuk and Baru. The latter was created after November 2002 phreatic eruption. Since 2011, numerous volcano-tectonic B events are encountered and the volcano was set on alert status on several occasions. The purpose of the present study is to delineate the structure of the summital hydrothermal system from Self-Potential (SP), soil temperature and gas concentrations in the soil (CO2, SO2 and H2S) data. This combination of geophysical and geochemical methods allows identification of the weak permeable zones serving as preferential pathways for hydrothermal circulation and potential candidates to future landslides or flank collapses. This study is an on-going collaborative research project and we plan to conduct electrical resistivity tomography (ERT) and also Induced-Polarization (IP) surveys. Additional data would allow the 3D imaging of the studied area. The IP parameters will be used to characterise and to quantify the degree of alteration of the volcanic rocks as has been shown very recently in the laboratory studies. There are also rocks and soil samples that will undergo laboratory analyses at ISTerre for IP and complex resistivity parameters at the sample scale that will help to interpret the survey results.

  15. Typical gray matter axons in mammalian brain fail to conduct action potentials faithfully at fever-like temperatures.

    Science.gov (United States)

    Pekala, Dobromila; Szkudlarek, Hanna; Raastad, Morten

    2016-10-01

    We studied the ability of typical unmyelinated cortical axons to conduct action potentials at fever-like temperatures because fever often gives CNS symptoms. We investigated such axons in cerebellar and hippocampal slices from 10 to 25 days old rats at temperatures between 30 and 43°C. By recording with two electrodes along axonal pathways, we confirmed that the axons were able to initiate action potentials, but at temperatures >39°C, the propagation of the action potentials to a more distal recording site was reduced. This temperature-sensitive conduction may be specific for the very thin unmyelinated axons because similar recordings from myelinated CNS axons did not show conduction failures. We found that the conduction fidelity improved with 1 mmol/L TEA in the bath, probably due to block of voltage-sensitive potassium channels responsible for the fast repolarization of action potentials. Furthermore, by recording electrically activated antidromic action potentials from the soma of cerebellar granule cells, we showed that the axons failed less if they were triggered 10-30 msec after another action potential. This was because individual action potentials were followed by a depolarizing after-potential, of constant amplitude and shape, which facilitated conduction of the following action potentials. The temperature-sensitive conduction failures above, but not below, normal body temperature, and the failure-reducing effect of the spike's depolarizing after-potential, are two intrinsic mechanisms in normal gray matter axons that may help us understand how the hyperthermic brain functions. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  16. Impact of temperature and electrical potentials on the stability and structure of collagen adsorbed on the gold electrode

    Science.gov (United States)

    Meiners, Frank; Ahlers, Michael; Brand, Izabella; Wittstock, Gunther

    2015-01-01

    The morphology and structure of collagen type I adsorbed on gold electrodes were studied as a function of electrode potential and temperature by means of capacitance measurements, polarization modulation infrared reflection-absorption spectroscopy and scanning force microscopy at temperatures of 37 °C, 43 °C and 50 °C. The selected temperatures corresponded to the normal body temperature, temperature of denaturation of collagen molecules and denaturation of collagen fibrils, respectively. Independently of the solution temperature, collagen was adsorbed on gold electrodes in the potential range - 0.7 V collagen molecules made a direct contact to the gold surface and water was present in the film. Protein molecules were oriented preferentially with their long axis towards the gold surface. Collagen molecules in the adsorbed state preserved their native triple helical structure even at temperatures corresponding to collagen denaturation in aqueous solutions. Application of E collagen molecules. A temperature increase to 50 °C leads to a distortion of the collagen film. The processes of aggregation and fibrilization were preferred over thermal denaturation for collagen adsorbed on the electrode surface and exposed to changing potentials.

  17. Methylphenidate alters flash-evoked potentials, body temperature, and behavior in Long-Evans rats.

    Science.gov (United States)

    Hetzler, Bruce E; Meckel, Katherine R; Stickle, Bruce A

    2014-01-01

    This experiment examined the effects of methylphenidate hydrochloride on flash-evoked potentials (FEPs) recorded from the visual cortex (VC) and superior colliculus (SC) of chronically implanted male Long-Evans rats, as well as on body temperature and open field behavior. FEPs were recorded at 10, 20 and 40 min following intraperitoneal injections of saline, and of doses of 0.7, 2.9, and 11.6 mg/kg methylphenidate on separate days. The 0.7 mg/kg dose did not produce significant effects. In the VC, following administration of the 11.6 mg/kg dose of methylphenidate the amplitude of components P83, N146, and P232 decreased, the amplitude of component N64 briefly increased and components P23, N30, N40, and P48 were unchanged in amplitude. In the SC, component P29 was unaffected, while components P38 and N51 were reduced in amplitude by the 11.6 mg/kg dose of methylphenidate. Peak latencies of components N40, P48, P83, and N146 in the VC and component P38 in the SC were increased by the 11.6 mg/kg dose of methylphenidate. When body temperature was recorded 45 min after drug administration, a mild dose-dependent hypothermia was found with the 2.9 and 11.6 mg/kg methylphenidate doses, suggesting that this may have contributed to the increased latencies. In subsequent open field observations, both line crossings and rearings were significantly increased by the 11.6 mg/kg dose. Increased movement into the center of the testing area was also observed, which could be a sign of increased exploration and reduced anxiety following methylphenidate.

  18. Germination response of Hylocereus setaceus (Salm-Dyck ex DC: ) Ralf Bauer (Cactaceae) seeds to temperature and reduced water potentials.

    Science.gov (United States)

    Simão, E; Takaki, M; Cardoso, V J M

    2010-02-01

    The germination response of Hylocereus setaceus seeds to isothermic incubation at different water potentials was analysed by using the thermal time and hydrotime models, aiming to describe some germination parameters of the population and to test the validity of the models to describe the response of the seeds to temperature and water potential. Hylocereus setaceus seeds germinated relatively well in a wide range of temperatures and the germination was rate limited from 11 to 20 degrees C interval and beyond 30 degrees C until 40 degrees C, in which the germination rate respectively shifts positively and negatively with temperature. The minimum or base temperature (T(b)) for the germination of H. setaceus was 7 degrees C, and the ceiling temperature varied nearly from 43.5 to 59 degrees C depending on the percent fraction, with median set on 49.8 degrees C. The number of degrees day necessary for 50% of the seeds to germinate in the infra-optimum temperature range was 39.3 degrees C day, whereas at the supra-optimum interval the value of theta = 77 was assumed to be constant throughout. Germination was sensitive to decreasing values of psi in the medium, and both the germinability and the germination rate shift negatively with the reduction of psi, but the rate of reduction changed with temperature. The values of base water potential (psi(b)) shift to zero with increasing temperatures and such variation reflects in the relatively greater effect of low psi on germination in supra optimum range of T. In general, the model described better the germination time courses at lower than at higher water potentials. The analysis also suggest that Tb may not be independent of psi and that psi(b(g)) may change as a function of temperature at the infra-otimum temperature range.

  19. Magnetic field effects on the static quark potential at zero and finite temperature

    Science.gov (United States)

    Bonati, Claudio; D'Elia, Massimo; Mariti, Marco; Mesiti, Michele; Negro, Francesco; Rucci, Andrea; Sanfilippo, Francesco

    2016-11-01

    We investigate the static Q Q ¯ potential at zero and finite temperature in the presence of a constant and uniform external magnetic field B →, for several values of the lattice spacing and for different orientations with respect to B →. As a byproduct, we provide continuum limit extrapolated results for the string tension, the Coulomb coupling and the Sommer parameter at T =0 and B =0 . We confirm the presence in the continuum of a B -induced anisotropy, regarding essentially the string tension, for which it is of the order of 15% at |e |B ˜1 GeV2 and would suggest, if extrapolated to larger fields, a vanishing string tension along the magnetic field for |e |B ≳4 GeV2. The angular dependence for |e |B ≲1 GeV2 can be nicely parametrized by the first allowed term in an angular Fourier expansion, corresponding to a quadrupole deformation. Finally, for T ≠0 , the main effect of the magnetic field is a general suppression of the string tension, leading to a early loss of the confining properties: this happens even before the appearance of inverse magnetic catalysis in the chiral condensate, supporting the idea that the influence of the magnetic field on the confining properties is the leading effect originating the decrease of Tc as a function of B .

  20. Magnetic field effects on the static quark potential at zero and finite temperature

    CERN Document Server

    Bonati, Claudio; Mariti, Marco; Mesiti, Michele; Negro, Francesco; Rucci, Andrea; Sanfilippo, Francesco

    2016-01-01

    We investigate the static $Q\\bar{Q}$ potential at zero and finite temperature in the presence of a constant and uniform external magnetic field $\\vec{B}$, for several values of the lattice spacing and for different orientations with respect to $\\vec{B}$. As a byproduct, we provide continuum limit extrapolated results for the string tension, the Coulomb coupling and the Sommer parameter at $T = 0$ and $B = 0$. We confirm the presence in the continuum of a $B$-induced anisotropy, regarding essentially the string tension, for which it is of the order of 15\\% at $|e| B \\sim 1~{\\rm GeV}^2$ and would suggest, if extrapolated to larger fields, a vanishing string tension along the magnetic field for $|e| B \\gtrsim 4$ GeV$^2$. The angular dependence for $|e| B \\lesssim 1$ GeV$^2$ can be nicely parametrized by the first allowed term in an angular Fourier expansion, corresponding to a quadrupole deformation. Finally, for $T \

  1. Definition of a moist entropic potential temperature. Application to FIRE-I data flights

    CERN Document Server

    Marquet, Pascal

    2014-01-01

    A moist entropy potential temperature -- denoted by ${\\theta}_{s}$ -- is defined analytically in terms of the specific entropy for moist air. The expression for ${\\theta}_{s}$ is valid for a general mixing of dry air, water vapour and possible condensed water species. It verifies the same conservative properties as the moist entropy, even for varying dry air or total water content. The moist formulation for ${\\theta}_{s}$ is equal to the dry formulation $\\theta$ if dry air is considered and it verifies new properties valid for the moist air cases, both saturated or under-saturated ones. Exact and approximate versions of ${\\theta}_{s}$ are evaluated for several Stratocumulus cases, in particular by using the aircraft observations FIRE-I experiment data sets. It appears that there is no (or small) jump in ${\\theta}_{s}$ at the top of the PBL. The mixing in moist entropy is almost complete in the PBL, with the same values observed in the clear air and the cloudy regions, including the very top of the entrainment...

  2. Laser-evoked brain potentials in patients with dissociated loss of pain and temperature sensibility.

    Science.gov (United States)

    Bromm, B; Frieling, A; Lankers, J

    1991-01-01

    Brief heat stimuli, elicited by a CO2 laser (10.6 microns wave length), activate the most superficial cutaneous nerve terminals of the thin myelinated A delta and unmyelinated C fibres which mediate heat and pain sensations. This paper investigates late cerebral potentials (SEPs) in response to laser pulses in comparison with those to conventional electrical stimulation in 18 patients with a dissociated sensory deficit (intact mechano-sensibility and disturbed temperature and pain sensation). Patients were stimulated in the most disturbed limb (affected area) and in a corresponding control area. In all 18 patients the SEPs elicited by laser stimuli were able to identify the body site with heaviest disturbances in pain and thermo-sensibility: the SEPs from the affected area were reduced or delayed, compared to the control area. In contrast, no alterations in SEPs could be observed after conventional electrical nerve stimulation, in agreement with the normal mechano-sensibility. However, the degree of SEP modulation in response to cutaneous heat stimuli did not correspond to the severity of the subjectively reported sensory deficit. Highest correlations between sensory deficits and abnormal SEPs were found in all those patients in whom computer tomography or MR imaging documented a localized destructive process in the CNS. All patients with the smallest SEP modulations despite a considerable sensory deficit had an inflammatory aetiology. Preliminary criteria to define a laser-evoked SEP as pathological are discussed.

  3. Temperature Dependence of Receptor Potential and Noise in Fly (Calliphora erythrocephala) Photoreceptor Cells

    NARCIS (Netherlands)

    Roebroek, J.G.H.; Tjonger, M. van; Stavenga, D.G.

    1990-01-01

    We investigated the effect of temperature on the response to light of photoreceptors of the blowfly Calliphora erythrocephala. The latency and the time-to-peak of the responses become shorter as the temperature increases; Q10 = 2.8 ± 0.6. The response amplitude is independent of the temperature in t

  4. Variation among genotypes in responses to increasing temperature in a marine parasite: evolutionary potential in the face of global warming?

    Science.gov (United States)

    Berkhout, Boris W; Lloyd, Melanie M; Poulin, Robert; Studer, Anja

    2014-11-01

    Climates are changing worldwide, and populations are under selection to adapt to these changes. Changing temperature, in particular, can directly impact ectotherms and their parasites, with potential consequences for whole ecosystems. The potential of parasite populations to adapt to climate change largely depends on the amount of genetic variation they possess in their responses to environmental fluctuations. This study is, to our knowledge, the first to look at differences among parasite genotypes in response to temperature, with the goal of quantifying the extent of variation among conspecifics in their responses to increasing temperature. Snails infected with single genotypes of the trematode Maritrema novaezealandensis were sequentially acclimatised to two different temperatures, 'current' (15°C) and 'elevated' (20°C), over long periods. These temperatures are based on current average field conditions in the natural habitat and those predicted to occur during the next few decades. The output and activity of cercariae (free-swimming infective stages emerging from snails) were assessed for each genotype at each temperature. The results indicate that, on average, both cercarial output and activity are higher at the elevated acclimation temperature. More importantly, the output and activity of cercariae are strongly influenced by a genotype-by-temperature interaction, such that different genotypes show different responses to increasing temperature. Both the magnitude and direction (increase or decrease) of responses to temperature varied widely among genotypes. Therefore, there is much potential for natural selection to act on this variation, and predicting how the trematode M. novaezealandensis will respond to the climate changes predicted for the next century will prove challenging.

  5. Canopy Temperature Depression as a Potential Selection Criterion for Drought Resistance in Wheat

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Field studies were conducted at Bushland, Texas, USA, in 2004 to examine usefulness of canopy temperature depression (CTD), the difference of air-canopy temperature, in screening wheat (Triticum aestivurm L.) genotypes for yield under dryland and irrigated. Forty winter wheat genotypes were grown under irrigation and dryland. CTDs were recorded after heading between 1 330 and 1530 h on 6 clear days for dryland and 9 days for irrigation. Drought susceptible index (DSI) for each genotype was calculated using mean yield under dryland and irrigated conditions. Genotypes exhibited great differences in CTD under each environment. The dryland CTDs averaged 1.33℃ ranging from -0.67 to 2.57℃, and the average irrigation CTD were 4.59℃ ranging from 3.21 to 5.62℃. A low yield reduction was observed under dryland conditions relative to irrigated conditions for high-CTD genotypes. CTD values were highly negatively correlated with DSI under dryland, and genotypes of CTDs=1.3℃ in dryland condition were identified as drought resistant. For 21 genotypes classified as drought resistant by DSI, their CTDs were 1.68℃ for dryland and 4.35℃ for irrigation on average; for 19 genotypes classified as drought susceptible by DSI, average CTD was 0.94℃ in dryland and 4.85℃ in irrigation. The high-yield genotypes consistently had high CTD values, and the low-yield ones had low CTD values for all measurements in dryland. After heading, genotypes maintained consistent ranking for CTD. Regression results for CTD and yield suggested that the best time for taking CTD measurement was 3-4 weeks after heading in irrigation but any time before senescence in dryland. Crop water stress index (CWSI) calculated from CTD data was highly correlated with CWSI calculated from yield, which suggesting traditional costly CWSI measurement may be improved by using portable infrared thermometers. Most importantly, grain yield was highly correlated with CTD under dryland (R2=0.79-0.86) and irrigation

  6. Evolution of vertebrate transient receptor potential vanilloid 3 channels: opposite temperature sensitivity between mammals and western clawed frogs.

    Directory of Open Access Journals (Sweden)

    Shigeru Saito

    2011-04-01

    Full Text Available Transient Receptor Potential (TRP channels serve as temperature receptors in a wide variety of animals and must have played crucial roles in thermal adaptation. The TRP vanilloid (TRPV subfamily contains several temperature receptors with different temperature sensitivities. The TRPV3 channel is known to be highly expressed in skin, where it is activated by warm temperatures and serves as a sensor to detect ambient temperatures near the body temperature of homeothermic animals such as mammals. Here we performed comprehensive comparative analyses of the TRPV subfamily in order to understand the evolutionary process; we identified novel TRPV genes and also characterized the evolutionary flexibility of TRPV3 during vertebrate evolution. We cloned the TRPV3 channel from the western clawed frog Xenopus tropicalis to understand the functional evolution of the TRPV3 channel. The amino acid sequences of the N- and C-terminal regions of the TRPV3 channel were highly diversified from those of other terrestrial vertebrate TRPV3 channels, although central portions were well conserved. In a heterologous expression system, several mammalian TRPV3 agonists did not activate the TRPV3 channel of the western clawed frog. Moreover, the frog TRPV3 channel did not respond to heat stimuli, instead it was activated by cold temperatures. Temperature thresholds for activation were about 16 °C, slightly below the lower temperature limit for the western clawed frog. Given that the TRPV3 channel is expressed in skin, its likely role is to detect noxious cold temperatures. Thus, the western clawed frog and mammals acquired opposite temperature sensitivity of the TRPV3 channel in order to detect environmental temperatures suitable for their respective species, indicating that temperature receptors can dynamically change properties to adapt to different thermal environments during evolution.

  7. Lidar measurements of the atmospheric entrainment zone and the potential temperature jump across the top of the mixed layer

    Science.gov (United States)

    Boers, R.; Eloranta, E. W.

    1986-01-01

    Lidar data of the atmospheric entrainment zone from six days of clear air convection obtained in central Illinois during July 1979 are presented. A new method to measure the potential temperature jump across the entrainment zone based on only one temperature sounding and continuous lidar measurements of the mixed layer height is developed. An almost linear dependence is found between the normalized entrainment rate and the normalized thickness of the entrainment zone.

  8. Global temperature change potential of nitrogen use in agriculture: A 50-year assessment

    Science.gov (United States)

    Fagodiya, R. K.; Pathak, H.; Kumar, A.; Bhatia, A.; Jain, N.

    2017-01-01

    Nitrogen (N) use in agriculture substantially alters global N cycle with the short- and long-term effects on global warming and climate change. It increases emission of nitrous oxide, which contributes 6.2%, while carbon dioxide and methane contribute 76% and 16%, respectively of the global warming. However, N causes cooling due to emission of NOx, which alters concentrations of tropospheric ozone and methane. NOx and NH3 also form aerosols with considerable cooling effects. We studied global temperature change potential (GTP) of N use in agriculture. The GTP due to N2O was 396.67 and 1168.32 Tg CO2e on a 20-year (GTP20) and 439.94 and 1295.78 Tg CO2e on 100-year scale (GTP100) during years 1961 and 2010, respectively. Cooling effects due to N use were 92.14 and 271.39 Tg CO2e (GTP20) and 15.21 and 44.80 Tg CO2e (GTP100) during 1961 and 2010, respectively. Net GTP20 was 369.44 and 1088.15 Tg CO2e and net GTP100 was 429.17 and 1264.06 Tg CO2e during 1961 and 2010, respectively. Thus net GTP20 is lower by 6.9% and GTP100 by 2.4% compared to the GTP considering N2O emission alone. The study shows that both warming and cooling effects should be considered to estimate the GTP of N use.

  9. Global temperature change potential of nitrogen use in agriculture: A 50-year assessment

    Science.gov (United States)

    Fagodiya, R. K.; Pathak, H.; Kumar, A.; Bhatia, A.; Jain, N.

    2017-03-01

    Nitrogen (N) use in agriculture substantially alters global N cycle with the short- and long-term effects on global warming and climate change. It increases emission of nitrous oxide, which contributes 6.2%, while carbon dioxide and methane contribute 76% and 16%, respectively of the global warming. However, N causes cooling due to emission of NOx, which alters concentrations of tropospheric ozone and methane. NOx and NH3 also form aerosols with considerable cooling effects. We studied global temperature change potential (GTP) of N use in agriculture. The GTP due to N2O was 396.67 and 1168.32 Tg CO2e on a 20-year (GTP20) and 439.94 and 1295.78 Tg CO2e on 100-year scale (GTP100) during years 1961 and 2010, respectively. Cooling effects due to N use were 92.14 and 271.39 Tg CO2e (GTP20) and 15.21 and 44.80 Tg CO2e (GTP100) during 1961 and 2010, respectively. Net GTP20 was 369.44 and 1088.15 Tg CO2e and net GTP100 was 429.17 and 1264.06 Tg CO2e during 1961 and 2010, respectively. Thus net GTP20 is lower by 6.9% and GTP100 by 2.4% compared to the GTP considering N2O emission alone. The study shows that both warming and cooling effects should be considered to estimate the GTP of N use.

  10. Global temperature change potential of nitrogen use in agriculture: A 50-year assessment.

    Science.gov (United States)

    Fagodiya, R K; Pathak, H; Kumar, A; Bhatia, A; Jain, N

    2017-03-21

    Nitrogen (N) use in agriculture substantially alters global N cycle with the short- and long-term effects on global warming and climate change. It increases emission of nitrous oxide, which contributes 6.2%, while carbon dioxide and methane contribute 76% and 16%, respectively of the global warming. However, N causes cooling due to emission of NOx, which alters concentrations of tropospheric ozone and methane. NOx and NH3 also form aerosols with considerable cooling effects. We studied global temperature change potential (GTP) of N use in agriculture. The GTP due to N2O was 396.67 and 1168.32 Tg CO2e on a 20-year (GTP20) and 439.94 and 1295.78 Tg CO2e on 100-year scale (GTP100) during years 1961 and 2010, respectively. Cooling effects due to N use were 92.14 and 271.39 Tg CO2e (GTP20) and 15.21 and 44.80 Tg CO2e (GTP100) during 1961 and 2010, respectively. Net GTP20 was 369.44 and 1088.15 Tg CO2e and net GTP100 was 429.17 and 1264.06 Tg CO2e during 1961 and 2010, respectively. Thus net GTP20 is lower by 6.9% and GTP100 by 2.4% compared to the GTP considering N2O emission alone. The study shows that both warming and cooling effects should be considered to estimate the GTP of N use.

  11. Calculation of Equation of State of QCD at Finite Chemical Potential and Temperature

    Institute of Scientific and Technical Information of China (English)

    QIAO Qing-Peng; ZONG Hong-Shi; TANG Jian; HOU Feng-Yao; LI Xue-Qian; SUN Wei-Min; L(U) Xiao-Fu

    2008-01-01

    In this paper, using path integral techniques we derive a model-independent formula for the pressure density (μ, T) (or equivalently the partition function) of Quantum Chromodynamics (QCD), which gives the equation of state (EOS) of QCD at finite chemical potential and temperature. In this formula the pressure density (μ, T) consists of two terms: the first term (μ,T) T=0) is a #-independent (but T-dependent) constant; the second term is totally determined by G[μ, T] (p ωn) (the dressed quark propagator at finite μ and finite T), which contains all the nontrivial μ-dependence. Then, in the framework of the rainbow-ladder approximation of the Dyson-Schwinger (DS) approach and under the approximation of neglecting the μ-dependence of the dressed gluon propagator, we show that G[μ, T] (p, ωn) can be obtained from G[T] (p, ωn) (the dressed quark propagator at μ = 0) by the substitution ωn →ωn + iμ. This result facilitates numerical calculations considerably. By this result, once G[T](p, ωn) is known, one can determine the EOS of QCD under the above approximations (up to the additive term (μ, T)[T=0). Finally, a comparison of the present EOS of QCD and the EOS obtained in the previous literatures in the framework of the rainbow-ladder approximation of the DS approach is given. It is found that the EOS given in the previous literatures does not satisfy the thermodynamic relation p(μ, T) = T.

  12. Ammonia and temperature determine potential clustering in the anaerobic digestion microbiome.

    Science.gov (United States)

    De Vrieze, Jo; Saunders, Aaron Marc; He, Ying; Fang, Jing; Nielsen, Per Halkjaer; Verstraete, Willy; Boon, Nico

    2015-05-15

    Anaerobic digestion is regarded as a key environmental technology in the present and future bio-based economy. The microbial community completing the anaerobic digestion process is considered complex, and several attempts already have been carried out to determine the key microbial populations. However, the key differences in the anaerobic digestion microbiomes, and the environmental/process parameters that drive these differences, remain poorly understood. In this research, we hypothesized that differences in operational parameters lead to a particular composition and organization of microbial communities in full-scale installations. A total of 38 samples were collected from 29 different full-scale anaerobic digestion installations, showing constant biogas production in function of time. Microbial community analysis was carried out by means of amplicon sequencing and real-time PCR. The bacterial community in all samples was dominated by representatives of the Firmicutes, Bacteroidetes and Proteobacteria, covering 86.1 ± 10.7% of the total bacterial community. Acetoclastic methanogenesis was dominated by Methanosaetaceae, yet, only the hydrogenotrophic Methanobacteriales correlated with biogas production, confirming their importance in high-rate anaerobic digestion systems. In-depth analysis of operational and environmental parameters and bacterial community structure indicated the presence of three potential clusters in anaerobic digestion. These clusters were determined by total ammonia concentration, free ammonia concentration and temperature, and characterized by an increased relative abundance of Bacteroidales, Clostridiales and Lactobacillales, respectively. None of the methanogenic populations, however, could be significantly attributed to any of the three clusters. Nonetheless, further experimental research will be required to validate the existence of these different clusters, and to which extent the presence of these clusters relates to stable or sub

  13. Effects of anodizing potential and temperature on the growth of anodic TiO2 and its photoelectrochemical properties

    Science.gov (United States)

    Kapusta-Kołodziej, Joanna; Syrek, Karolina; Pawlik, Anna; Jarosz, Magdalena; Tynkevych, Olena; Sulka, Grzegorz D.

    2017-02-01

    Although nanoporous/nanotubular anodic TiO2 has been broadly investigated, there is still much to be learned about the fabrication, morphological characterization and applications of anodic TiO2 formed in the glycerol-based electrolyte. Nanoporous anodic titanium oxide (ATO) layers on Ti were prepared via a three-step anodization in a glycerol solution containing NH4F (0.38 wt%) and H2O (1.79 wt%). The effects of anodizing potential (30-70 V) and temperature (10-40 °C) on the growth and morphology of ATO layers were investigated in detail. The structural and morphological characterizations of received ATO layers were performed for the studied potentials and temperatures. Moreover, photoelectrochemical properties of formed TiO2 were studied as well. It has been shown, that the morphology of fabricated nanoporous ATO layers are strongly altered by anodizing temperature and potential. Particularly, an interesting finding is that the growth rate gradually increases up to 50 V independently of anodizing temperature and then decreases when anodizing potential increases to 70 V. Moreover, for all investigated anodizing temperatures, the structural features of ATO layers, such as the cell size, inner layer pore diameter, outer layer pore diameter, increase with increasing anodizing potential. The annealing of ATO samples synthesized at 20 °C revealed that the anatase grain size increases with increasing anodizing potential. It is noteworthy to mention that the highest photoconversion efficiency values were observed for samples synthesized at the anodizing temperature of 20 °C and 40 V.

  14. Potential of two-line atomic fluorescence for temperature imaging in turbulent indium-oxide-producing flames

    Energy Technology Data Exchange (ETDEWEB)

    Münsterjohann, Bettina; Huber, Franz J. T.; Klima, Tobias C.; Holfelder, Sandra; Engel, Sascha R. [Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Lehrstuhl für Technische Thermodynamik (LTT) (Germany); Miller, Joseph D. [Aerospace Systems Directorate, Air Force Research Laboratory (United States); Meyer, Terrence R. [Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen Graduate School in Advanced Optical Technologies (SAOT) (Germany); Will, Stefan, E-mail: stefan.will@fau.de [Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Lehrstuhl für Technische Thermodynamik (LTT) (Germany)

    2015-11-15

    The applicability of two-line atomic fluorescence (TLAF) for temperature imaging in an indium-based flame spray pyrolysis (FSP) process is demonstrated using a single tunable optical parametric oscillator (OPO) to generate the required excitation wavelengths consecutively. Single-shot images of the detected fluorescence signals demonstrate that the signal levels in the flame are suitable for evaluation of temperature and verify the capability and potential of the measurement technique directly during particle formation without additional indium seeding. Qualitative averaged two-dimensional temperature distributions in the FSP flame are presented, showing the influence of varying sheath gas flow rates on the resulting temperature distribution. With the addition of a second OPO and detection system, the two fluorescence signals acquired consecutively in this work could be obtained simultaneously and enable spatio-temporally resolved single-shot temperature measurements in flame synthesis processes of indium-containing nanoparticles.

  15. On the potential of solar cells to efficiently operate at high temperature

    Science.gov (United States)

    Zeitouny, Joya; Lalau, Noémie; Katz, Eugene A.; Dollet, Alain; Vossier, Alexis

    2017-09-01

    The development of high temperature CPV/thermal (CSP) hybrid systems appears to be a promising route to improve the overall solar to electricity conversion efficiency. Moreover, such systems would not only use the residual heat stemming from the unconverted fraction of the incident solar radiation in PV cells, but they would also provide the advantage of storing energy as heat. However, the performances of such hybrid systems depend strongly on the temperature of the thermal receivers which are only effective at high temperatures (typically above 250°C) while solar cells typically operate at temperatures close to ambient. An appropriate strategy is to make PV cells efficiently operate at temperature levels significantly exceeding the normal range of temperatures for which they are commonly designed. The degradation of electrical performance associated with high working temperature is less pronounced when the cell is submitted to high sunlight concentrations. An efficient photovoltaic conversion at temperature levels exceeding the ambient may however require significant modifications in the architecture of the cells. In this work, we assessed the feasibility of this strategy by studying the electrical properties as well as the overall efficiency of the PV/CSP system at different temperatures and sunlight illuminations.

  16. Dilepton production as a useful probe of quark gluon plasma with temperature dependent chemical potential quark mass

    Science.gov (United States)

    Kumar, Yogesh; Singh, S. Somorendro

    2016-07-01

    We extend the previous study of dilepton production using [S. Somorendro Singh and Y. Kumar, Can. J. Phys. 92 (2014) 31] based on a simple quasiparticle model of quark-gluon plasma (QGP). In this model, finite value of quark mass uses temperature dependent chemical potential the so-called Temperature Dependent Chemical Potential Quark Mass (TDCPQM). We calculate dilepton production in the relevant range of mass region. It is observed that the production rate is marginally enhanced from the earlier work. This is due to the effect of TDCPQM and its effect is highly significant in the production of dilepton.

  17. Fermionic dispersion relations at finite temperature and non-vanishing chemical potentials in the minimal standard model

    CERN Document Server

    Morales, J; Fonseca, F; Morales, John; Quimbay, Carlos; Fonseca, Frank

    1999-01-01

    We calculate the fermionic dispersion relations in the minimal standard model at finite temperature in presence of non-vanishing chemical potentials due to the CP-asymmetric fermionic background. The dispersion relations are calculated for a vacuum expectation value of the Higgs field equal to zero (unbroken electroweak symmetry). The calculation is performed in the real time formalism of the thermal field theory at one-loop order in a general $\\xi$ gauge. The fermionic self-energy is calculated at leading order in temperature and chemical potential and this fact permits us to obtain gauge invariant analytical expressions for the dispersion relations.

  18. Temperature dependence of the pinning potential in the high-temperature superconductor Y1Ba2Cu3O7- x

    Science.gov (United States)

    Dobbert, O.; Dinse, K.-P.; Goldacker, W.; Wolf, T.

    1991-06-01

    Combining the results of magnetization decay and microwave absorption experiments the logarithmic flux decay in twinned YBaCuO crystals was studied over a wide temperature range ( Θ=0.1 to 0.8) under conditions of small applied external fields ( B=2.4 mT). The resulting quasi exponential temperature dependence of the pinning potential can be modelled satisfactorily by assuming a structural limitation for the shielding current, resulting from S-N-S barriers. The temperature dependence in the crystalline material is similar to jcr(Θ) observed for epitaxic YBaCuO films, and leads to an estimate of the barrier width of the order of 10 nm.

  19. Temperature oscillations near natural nuclear reactor cores and the potential for prebiotic oligomer synthesis.

    Science.gov (United States)

    Adam, Zachary R

    2016-06-01

    Geologic settings capable of driving prebiotic oligomer synthesis reactions remain a relatively unexplored aspect of origins of life research. Natural nuclear reactors are an example of Precambrian energy sources that produced unique temperature fluctuations. Heat transfer models indicate that water-moderated, convectively-cooled natural fission reactors in porous host rocks create temperature oscillations that resemble those employed in polymerase chain reaction (PCR) devices to artificially amplify oligonucleotides. This temperature profile is characterized by short-duration pulses up to 70-100 °C, followed by a sustained period of temperatures in the range of 30-70 °C, and finally a period of relaxation to ambient temperatures until the cycle is restarted by a fresh influx of pore water. For a given reactor configuration, temperature maxima and the time required to relax to ambient temperatures depend most strongly on the aggregate effect of host rock permeability in decreasing the thermal expansion and increasing the viscosity and evaporation temperature of the pore fluids. Once formed, fission-fueled reactors can sustain multi-kilowatt-level power production for 10(5)-10(6) years, ensuring microenvironmental longevity and chemical output. The model outputs indicate that organic synthesis on young planetary bodies with a sizeable reservoir of fissile material can involve more sophisticated energy dissipation pathways than modern terrestrial analog settings alone would suggest.

  20. Temperature oscillations near natural nuclear reactor cores and the potential for prebiotic oligomer synthesis

    Science.gov (United States)

    Adam, Zachary R.

    2016-06-01

    Geologic settings capable of driving prebiotic oligomer synthesis reactions remain a relatively unexplored aspect of origins of life research. Natural nuclear reactors are an example of Precambrian energy sources that produced unique temperature fluctuations. Heat transfer models indicate that water-moderated, convectively-cooled natural fission reactors in porous host rocks create temperature oscillations that resemble those employed in polymerase chain reaction (PCR) devices to artificially amplify oligonucleotides. This temperature profile is characterized by short-duration pulses up to 70-100 °C, followed by a sustained period of temperatures in the range of 30-70 °C, and finally a period of relaxation to ambient temperatures until the cycle is restarted by a fresh influx of pore water. For a given reactor configuration, temperature maxima and the time required to relax to ambient temperatures depend most strongly on the aggregate effect of host rock permeability in decreasing the thermal expansion and increasing the viscosity and evaporation temperature of the pore fluids. Once formed, fission-fueled reactors can sustain multi-kilowatt-level power production for 105-106 years, ensuring microenvironmental longevity and chemical output. The model outputs indicate that organic synthesis on young planetary bodies with a sizeable reservoir of fissile material can involve more sophisticated energy dissipation pathways than modern terrestrial analog settings alone would suggest.

  1. S-parameter at Non-Zero Temperature and Chemical Potential

    DEFF Research Database (Denmark)

    Søndergaard, Ulrik Ishøj; Sannino, Francesco; Pica, Claudio

    2011-01-01

    We compute the finite-temperature and matter density corrections to the S-parameter at the one loop level. At non-zero temperature T and matter density Lorentz symmetry breaks and therefore we suggest a suitable generalization of the S-parameter. By computing the plasma correction, we discover...

  2. S-parameter at Non-Zero Temperature and Chemical Potential

    DEFF Research Database (Denmark)

    Søndergaard, Ulrik Ishøj; Sannino, Francesco; Pica, Claudio

    2011-01-01

    We compute the finite-temperature and matter density corrections to the S-parameter at the one loop level. At non-zero temperature T and matter density Lorentz symmetry breaks and therefore we suggest a suitable generalization of the S-parameter. By computing the plasma correction, we discover a ...

  3. Influence of temperature, anions and size distribution on the zeta potential of DMPC, DPPC and DMPE lipid vesicles.

    Science.gov (United States)

    Morini, M A; Sierra, M B; Pedroni, V I; Alarcon, L M; Appignanesi, G A; Disalvo, E A

    2015-07-01

    The purpose of the work is to compare the influence of the multilamellarity, phase state, lipid head groups and ionic media on the origin of the surface potential of lipid membranes. With this aim, we present a new analysis of the zeta potential of multilamellar and unilamellar vesicles composed by phosphatidylcholines (PC) and phosphatidylethanolamines (PE) dispersed in water and ionic solutions of polarizable anions, at temperatures below and above the phase transition. In general, the adsorption of anions seems to explain the origin of the zeta potential in vesicles only above the transition temperature (Tc). In this case, the sign of the surface potential is ascribed to a partial orientation of head group moiety toward the aqueous phase. This is noticeable in PC head groups but not in PEs, due to the strong lateral interaction between PO and NH group in PE.

  4. Near fifty percent sodium substituted lanthanum manganites—A potential magnetic refrigerant for room temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Sethulakshmi, N.; Anantharaman, M. R., E-mail: mraiyer@yahoo.com [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India); Al-Omari, I. A. [Department of Physics, Sultan Qaboos University, PC 123 Muscat, Sultanate of Oman (Oman); Suresh, K. G. [Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)

    2014-03-03

    Nearly half of lanthanum sites in lanthanum manganites were substituted with monovalent ion-sodium and the compound possessed distorted orthorhombic structure. Ferromagnetic ordering at 300 K and the magnetic isotherms at different temperature ranges were analyzed for estimating magnetic entropy variation. Magnetic entropy change of 1.5 J·kg{sup −1}·K{sup −1} was observed near 300 K. An appreciable magnetocaloric effect was also observed for a wide range of temperatures near 300 K for small magnetic field variation. Heat capacity was measured for temperatures lower than 300 K and the adiabatic temperature change increases with increase in temperature with a maximum of 0.62 K at 280 K.

  5. Extending the density functional embedding theory to finite temperature and an efficient iterative method for solving for embedding potentials

    Science.gov (United States)

    Huang, Chen

    2016-03-01

    A key element in the density functional embedding theory (DFET) is the embedding potential. We discuss two major issues related to the embedding potential: (1) its non-uniqueness and (2) the numerical difficulty for solving for it, especially for the spin-polarized systems. To resolve the first issue, we extend DFET to finite temperature: all quantities, such as the subsystem densities and the total system's density, are calculated at a finite temperature. This is a physical extension since materials work at finite temperatures. We show that the embedding potential is strictly unique at T > 0. To resolve the second issue, we introduce an efficient iterative embedding potential solver. We discuss how to relax the magnetic moments in subsystems and how to equilibrate the chemical potentials across subsystems. The solver is robust and efficient for several non-trivial examples, in all of which good quality spin-polarized embedding potentials were obtained. We also demonstrate the solver on an extended periodic system: iron body-centered cubic (110) surface, which is related to the modeling of the heterogeneous catalysis involving iron, such as the Fischer-Tropsch and the Haber processes. This work would make it efficient and accurate to perform embedding simulations of some challenging material problems, such as the heterogeneous catalysis and the defects of complicated spin configurations in electronic materials.

  6. Evaluation of low-temperature geothermal potential in north-central Box Elder County, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Davis, M.C.; Kolesar, P.T.

    1984-12-01

    The low-temperature geothermal resources of north-central Box Elder County, Utah were assessed. Exploration techniques used included chemical analyses of water from wells and springs, temperature surveys, and temperature-depth measurements in unused wells within the study area. The highest water temperatures (31/sup 0/, 30/sup 0/, and 29/sup 0/C) recorded in this research were located in three separate geographic regions, suggesting that no single warm water occurrence dominates the study area. Total dissolved solid (TDS) concentrations ranged from 294 to 11,590 mg/l. Areas of warm water occurrences generally had TDS values of greater than 1100 mg/l. Reservoir temperatures were estimated using chemical geothermometers. Calculated temperatures ranged between 50/sup 0/ and 100/sup 0/C. Temperature-depth measurements were logged in 16 unused wells. Thermal gradients calculated from the profiles ranged from isothermal to 267/sup 0/C/km. The background gradient for the study area appears to be slightly above the average Basin and Range gradient of 35/sup 0/C/km. The highest gradients were calculated for the area approximately eight kilometers west of Snowville, Utah, which is also an area of warm water. 61 refs., 15 figs., 6 tabs.

  7. Gravitropic reaction of primary seminal roots of Zea mays L. influenced by temperature and soil water potential.

    Science.gov (United States)

    Nakamoto, T

    1995-03-01

    The growth of the primary seminal root of maize (Zea mays L.) is characterized by an initial negative gravitropic reaction and a later positive one that attains a plagiotropic liminal angle. The effects of temperature and water potential of the surrounding soil on these gravitropic reactions were studied. Temperatures of 32, 25, and 18C and soil water potentials of -5, -38, and -67 kPa were imposed and the direction of growth was measured for every 1 cm length of the root. The initial negative gravitropic reaction extended to a distance of about 10 cm from the grain. Higher temperatures reduced the initial negative gravitropic reaction. Lower soil water potential induced a downward growth at root emergence. A mathematical model, in which it was assumed that the rate of the directional change of root growth was a sum of a time-dependent negative gravitropic reaction and an establishment of the liminal angle, adequately fitted the distance-angle relations. It was suggested that higher temperatures and/or a lower water potential accelerated the diminution of the initial negative gravitropic reaction.

  8. Accelerated Testing and Modeling of Potential-Induced Degradation as a Function of Temperature and Relative Humidity

    DEFF Research Database (Denmark)

    Hacke, Peter; Spataru, Sergiu; Terwilliger, Kent;

    2015-01-01

    An acceleration model based on the Peck equation was applied to power performance of crystalline silicon cell modules as a function of time and of temperature and humidity, which are the two main environmental stress factors that promote potential-induced degradation (PID). This model was derived...

  9. Accelerated Testing and Modeling of Potential-Induced Degradation as a Function of Temperature and Relative Humidity

    DEFF Research Database (Denmark)

    Hacke, Peter; Spataru, Sergiu; Terwilliger, Kent;

    2015-01-01

    An acceleration model based on the Peck equation was applied to power performance of crystalline silicon cell modules as a function of time and of temperature and humidity, the two main environmental stress factors that promote potential-induced degradation. This model was derived from module pow...

  10. Mean and Flux Horizontal Variability of Virtual Potential Temperature, Moisture, and Carbon Dioxide: Aircraft Observations and LES Study

    NARCIS (Netherlands)

    Górska, M.; Vilà-Guerau de Arellano, J.; LeMone, M.A.; Heerwaarden, van C.C.

    2008-01-01

    The effects of the horizontal variability of surface properties on the turbulent fluxes of virtual potential temperature, moisture, and carbon dioxide are investigated by combining aircraft observations with large-eddy simulations (LESs). Daytime fair-weather aircraft measurements from the 2002 Inte

  11. Transient receptor potential is essential for high temperature tolerance in invasive Bemisia tabaci Middle East Asia minor 1 cryptic species.

    Directory of Open Access Journals (Sweden)

    Zhi-Chuang Lü

    Full Text Available Temperature is an important factor in affecting population dynamics and diffusion distribution of organisms. Alien species can successfully invade and colonize to various temperature environments, and one of important reasons is that alien species have a strong resistance to stress temperature. Recently, researchers have focused on the mechanisms of temperature sensing to determine the sensing and regulation mechanisms of temperature adaptation. The transient receptor potential (TRP is one of the key components of an organism's temperature perception system. TRP plays important roles in perceiving temperature, such as avoiding high temperature, low temperature and choosing the optimum temperature. To assess high temperature sensation and the heat resistance role of the TRP gene, we used 3' and 5' rapid-amplification of cDNA ends to isolate the full-length cDNA sequence of the TRP gene from Bemisia tabaci (Gennadius MEAM1 (Middle East Asia Minor 1, examined the mRNA expression profile under various temperature conditions, and identified the heat tolerance function. This is the first study to characterize the TRP gene of invasive B. tabaci MEAM1 (MEAM1 BtTRP. The full-length cDNA of MEAM1 BtTRP was 3871 bp, and the open reading frames of BtTRP was 3501 bp, encoding 1166 amino acids. Additionally, the BtTRP mRNA expression level was significantly increased at 35°C. Furthermore, compared with control treatments, the survival rate of B. tabaci MEAM1 adults was significantly decreased under high temperature stress conditions after feeding with dsRNA BtTRP. Collectively, these results showed that MEAM1 BtTRP is a key element in sensing high temperature and plays an essential role in B. tabaci MEAM1 heat tolerance ability. Our data improved our understanding of the mechanism of temperature sensation in B. tabaci MEAM1 at the molecular level and could contribute to the understanding of the thermal biology of B. tabaci MEAM1 within the context of global

  12. Comparison of the effects of temperature and water potential on seed germination of Fabaceae species from desert and subalpine grassland.

    Science.gov (United States)

    Hu, Xiao Wen; Fan, Yan; Baskin, Carol C; Baskin, Jerry M; Wang, Yan Rong

    2015-05-01

    Temperature and water potential for germination based on the thermal and hydrotime models have been successfully applied in predicting germination requirements of physiologically dormant seeds as well as nondormant seeds. However, comparative studies of the germination requirements of physically dormant seeds from different ecosystems have not been done. Germination of scarified seeds of four legume species collected from the Qing-Tibetan Plateau and of four collected in the Alax Desert in China was compared over a range of temperatures and water potentials based on thermal time and hydrotime models. Seeds of species from the Qing-Tibetan Plateau had a lower base temperature (T b) and optimal temperature (T o) for germination than those from the Alax Desert. Seeds of the four species from the Qing-Tibetan Plateau germinated to high percentages at 5°C, whereas none of the four desert species did so. Seeds of species from the Alax Desert germinated to a high percentage at 35°C or 40°C, while no seeds of species from the Qing-Tibetan Plateau germinated at 35°C or 40°C. The base median water potential [Ψ b(50)] differed among species but not between the two habitats. The thermal time and hydrotime models accurately predicted the germination time course of scarified seeds of most of the eight species in response to temperature and water potential; thus, they can be useful tools in comparative studies on germination of seeds with physical dormancy. Habitat temperatures but not rainfall is closely related to germination requirements of these species. © 2015 Botanical Society of America, Inc.

  13. Stratospheric Horizontal Wavenumber Spectra of Winds, Potential Temperature, and Atmospheric Tracers Observed by High-Altitude Aircraft

    Science.gov (United States)

    Bacmeister, Julio T.; Eckermann, Stephen D.; Newman, Paul A.; Lait, Leslie; Chan, K. R.; Loewenstein, Max; Proffitt, Michael H.; Gary, Bruce L.

    1996-01-01

    Horizontal wavenumber power spectra of vertical and horizontal wind velocities, potential temperatures, and ozone and N(2)O mixing ratios, as measured in the mid-stratosphere during 73 ER-2 flights (altitude approx. 20km) are presented. The velocity and potential temperature spectra in the 100 to 1-km wavelength range deviate significantly from the uniform -5/3 power law expected for the inverse energy-cascade regime of two-dimensional turbulence and also for inertial-range, three-dimensional turbulence. Instead, steeper spectra approximately consistent with a -3 power law are observed at horizontal scales smaller than 3 km for all velocity components as well as potential temperature. Shallower spectra are observed at scales longer than 6 km. For horizontal velocity and potential temperature the spectral indices at longer scales are between -1.5 and -2.0. For vertical velocity the spectrum at longer scales become flat. It is argued that the observed velocity and potential temperature spectra are consistent with gravity waves. At smaller scales, the shapes are also superficially consistent with a Lumley-Shur-Weinstock buoyant subrange of turbulence and/or nonlinear gravity waves. Contemporaneous spectra of ozone and N(sub 2)O mixing ratio in the 100 to 1-km wavelength range do conform to an approximately uniform -5/3 power law. It is argued that this may reflect interactions between gravity wave air-parcel displacements and laminar or filamentary structures in the trace gas mixing ratio field produced by enstropy-cascading two-dimensional turbulence.

  14. Larval connectivity across temperature gradients and its potential effect on heat tolerance in coral populations.

    Science.gov (United States)

    Kleypas, Joan A; Thompson, Diane M; Castruccio, Frederic S; Curchitser, Enrique N; Pinsky, Malin; Watson, James R

    2016-11-01

    Coral reefs are increasingly exposed to elevated temperatures that can cause coral bleaching and high levels of mortality of corals and associated organisms. The temperature threshold for coral bleaching depends on the acclimation and adaptation of corals to the local maximum temperature regime. However, because of larval dispersal, coral populations can receive larvae from corals that are adapted to very different temperature regimes. We combine an offline particle tracking routine with output from a high-resolution physical oceanographic model to investigate whether connectivity of coral larvae between reefs of different thermal regimes could alter the thermal stress threshold of corals. Our results suggest that larval transport between reefs of widely varying temperatures is likely in the Coral Triangle and that accounting for this connectivity may be important in bleaching predictions. This has important implications in conservation planning, because connectivity may allow some reefs to have an inherited heat tolerance that is higher or lower than predicted based on local conditions alone. © 2016 John Wiley & Sons Ltd.

  15. The potential for reducing urban air temperatures and energy consumption through vegetative cooling

    Energy Technology Data Exchange (ETDEWEB)

    Kurn, D.M.; Bretz, S.E.; Huang, B.; Akbari, H.

    1994-05-01

    A network of 23 weather stations was used to detect existing oases in Southern California. Four stations, separated from one another by 15--25 miles (24--40 km), were closely examined. Data were strongly affected by the distance of the stations from the Pacific Ocean. This and other city-scale effects made the network inadequate for detection of urban oases. We also conducted traverse measurements of temperature and humidity in the Whittier Narrows Recreation Area in Los Angeles County on September 8--10, 1993. Near-surface air temperatures over vegetated areas were 1--2{degrees}C lower than background air temperatures. We estimate that vegetation may lower urban temperatures by 1{degrees}C, while the establishment of vegetative canopies may lower local temperatures by an additional 2{degrees}C. An increase in vegetation in residential neighborhoods may reduce peak loads in the Los Angeles area by 0.3 GW, and reduce energy consumption by 0.2 BkWh/year, saving $20 million annually. Large additional savings would result from regional cooling.

  16. Equation of state and interaction potential of helium under high temperatures and high densities

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on the thermodynamics statistic method, the improved variational perturbation theory and the modified quantum mechanics correction model have been used to calculate the equation of state of liquid helium at pressure from 0.7 to 108 GPa. The calculation results are in good agreement with the experimental data. The EXP-6 potential (α = 13.1) can more accurately describe the interaction of helium atoms than other potentials in the scheme. Finally, a comparison is shown between our interatomic potentials and other potentials.

  17. Equation of state and interaction potential of helium under high temperatures and high densities

    Institute of Scientific and Technical Information of China (English)

    YANG JinWen; YAN YuanHong

    2009-01-01

    Based on the thermodynamics statistic method, the improved variational perturbation theory and the modified quantum mechanics correction model have been used to calculate the equation of state of liquid helium at pressure from 0.7 to 108 GPa. The calculation results are in good agreement with the experimental data. The EXP-6 potential (α=13.1) can more accurately describe the interaction of helium atoms than other potentials in the scheme. Finally, s comparison is shown between our interatomic potentials and other potentials.

  18. Potential High-Temperature Shape-Memory-Alloy Actuator Material Identified

    Science.gov (United States)

    Noebe, Ronald D.; Gaydosh, Darrell J.; Biles, Tiffany A.; Garg, Anita

    2005-01-01

    Shape-memory alloys are unique "smart materials" that can be used in a wide variety of adaptive or "intelligent" components. Because of a martensitic solid-state phase transformation in these materials, they can display rather unusual mechanical properties including shape-memory behavior. This phenomenon occurs when the material is deformed at low temperatures (below the martensite finish temperature, Mf) and then heated through the martensite-to-austenite phase transformation. As the material is heated to the austenite finish temperature Af, it is able to recover its predeformed shape. If a bias is applied to the material as it tries to recover its original shape, work can be extracted from the shape-memory alloy as it transforms. Therefore, shape-memory alloys are being considered for compact solid-state actuation devices to replace hydraulic, pneumatic, or motor-driven systems.

  19. CoxC nanorod magnets: Highly magnetocrystalline anisotropy with lower Curie temperature for potential applications

    Energy Technology Data Exchange (ETDEWEB)

    El-Gendy, AA; Almugaiteeb, T; Carpenter, EE

    2013-12-01

    Magnetic CoxC nanorods with larger magnetocrystalline anisotropy of 5 x 10(5) J/m(3) as well as larger coercivity and lower Curie temperature are introduced. The particles have an average diameter of 8 nm and shows three different magnetic behaviors. The sample shows ferromagnetism up to 400 K, superparamagnetism at temperature > 400 K and

  20. Characterization of Lactococcus lactis mutants with improved performance at high temperatures and potential dairy applications

    DEFF Research Database (Denmark)

    Chen, Jun

    (TM29) capable of growing at 40ºC was successfully isolated. By determining the temperature dependent growth rate profile, a shift of the optimum temperature from 30ºC to 36ºC was observed for TM29. Meanwhile, metabolic flux analysis revealed that TM29 was able to hold higher glucose consumption...... microarray analysis revealed apparent differences in the transcriptional response to heat between the mutant and parent. It was found that SNPs preceding gene groESL and ribU resulted in over-expression of chaperone proteins GroES-GroEL, and membrane associated riboflavin transporter protein RibU in TM29...

  1. Potential energy savings using dynamically optimizing control in refrigeration systems under daily variations in ambient temperature

    DEFF Research Database (Denmark)

    Larsen, Lars Finn Sloth; Thybo, Claus; Wisniewski, Rafal;

    2007-01-01

    The objective of this study is to investigate the energy saving potential for refrigeration systems by refrigeration more at the colder night time than at the warmer day time. The potential is evaluated using an optimal control policy and illustrated on a simulation example. The results show that...

  2. Wellbore and groundwater temperature distribution eastern Snake River Plain, Idaho: Implications for groundwater flow and geothermal potential

    Science.gov (United States)

    McLing, Travis L.; Smith, Richard P.; Smith, Robert W.; Blackwell, David D.; Roback, Robert C.; Sondrup, Andrus J.

    2016-06-01

    A map of groundwater temperatures from the Eastern Snake River Plain (ESRP) regional aquifer can be used to identify and interpret important features of the aquifer, including aquifer flow direction, aquifer thickness, and potential geothermal anomalies. The ESRP is an area of high heat flow, yet most of this thermal energy fails to reach the surface, due to the heat being swept downgradient by the aquifer to the major spring complexes near Thousand Springs, ID, a distance of 300 km. Nine deep boreholes that fully penetrate the regional aquifer display three common features: (1) high thermal gradients beneath the aquifer, corresponding to high conductive heat flow in low-permeability hydrothermally-altered rocks; (2) isothermal temperature profiles within the aquifer, characteristic of an actively flowing groundwater; and (3) moderate thermal gradients in the vadose zone with values that indicate that over half of the geothermal heat flow is removed by advective transport in the regional aquifer system. This study utilized temperature data from 250 ESRP aquifer wells to evaluate regional aquifer flow direction, aquifer thickness, and potential geothermal anomalies. Because the thermal gradients are typically low in the aquifer, any measurement of groundwater temperature is a reasonable estimate of temperature throughout the aquifer thickness, allowing the construction of a regional aquifer temperature map for the ESRP. Mapped temperatures are used to identify cold thermal plumes associated with recharge from tributary valleys and adjacent uplands, and warm zones associated with geothermal input to the aquifer. Warm zones in the aquifer can have various causes, including local circulation of groundwater through the deep conductively dominated region, slow groundwater movement in low-permeability regions, or localized heat flow from deeper thermal features.

  3. Electronic ventilator temperature sensors as a potential source of respiratory tract colonization with Stenotrophomonas maltophilia.

    Science.gov (United States)

    Rogues, A M; Maugein, J; Allery, A; Fleureau, C; Boulestreau, H; Surcin, S; Bebear, C; Janvier, G; Gachie, J P

    2001-12-01

    Stenotrophomonas maltophilia (S. maltophilia) is an important cause of nosocomial infection among ventilated and immunocompromised patients, and among patients receiving broad-spectrum antimicrobials. We report a cluster of patients in a surgical intensive care unit who were colonized or infected with S. maltophilia. An epidemiological investigation was initiated after surveillance data revealed that eight patients were culture-positive from sputum for S. maltophilia in the preceding month. Review of respiratory care procedures revealed that when mechanical ventilators were serviced between patients, the electronic temperature probes used with servo-controlled humidifiers were wiped with inadequate disinfection. We collected cultures of case-patient room surfaces, sinks and ventilator equipment. S. maltophilia was recovered from room surfaces, ventilator expiratory circuits and a temperature sensor which had been kept in ambient air after disinfection. Patients and environmental isolates were examined by RAPD-PCR. Three clinical isolates and one environmental isolate had the same profile, which suggests cross-contamination or common source exposure. The outbreak was controlled by adequate disinfection of the temperature sensors. No single epidemic strain was identified but several observations support the conclusion that the temperature probes contributed to the outbreak.

  4. Cannabis co-administration potentiates MDMA effects on temperature and heart rate

    NARCIS (Netherlands)

    Dumont, G.; Kramers, C.; Sweep, E.; Touw, D.; Van Hasselt, J.; De Kam, M.; Van Gerven, J.; Buitelaar, J.; Verkes, R.J.

    2009-01-01

    3,4-methylenedioxymethamphetamine (MDMA or “ecstasy”) is a frequently used club-drug in Western societies. Ecstasy users generally are multi-drug users, and cannabis (THC) is commonly combined with MDMA. MDMA is a potent psychostimulant, increasing heart rate, blood pressure and body temperature. TH

  5. Modeling the Effect of Temperature and Potential on the In Vitro Corrosion Performance of Biomedical Hydroxyapatite Coatings

    Science.gov (United States)

    Coşkun, M. İbrahim; Karahan, İsmail H.; Yücel, Yasin; Golden, Teresa D.

    2016-10-01

    CoCrMo biomedical alloys were coated with a hydroxyapatite layer to improve biocompatibility and in vitro corrosion performance. A fast electrodeposition process was completed in 5 minutes for the hydroxyapatite coating. Effect of the solution temperature and applied potential on the in vitro corrosion performance of the hydroxyapatite coatings was modeled by response surface methodology (RSM) coupled with central composite design (CCD). A 5-level-2-factor experimental plan designed by CCD was used; the experimental plan contained 13 coating experiments with a temperature range from 283 K to 347 K (10 °C to 74 °C) and potential range from -1.2 to -1.9 V. Corrosion potential ( E corr) of the coatings in a simulated body fluid solution was chosen as response for the model. Predicted and experimental values fitted well with an R 2 value of 0.9481. Response surface plots of the impedance and polarization resistance ( R P) were investigated. Optimized parameters for electrodeposition of hydroxyapatite were determined by RSM as solution temperature of 305.48 K (32.33 °C) and potential of -1.55 V. Hydroxyapatite coatings fabricated at optimized parameters showed excellent crystal formation and high in vitro corrosion resistance.

  6. The Pyrexia transient receptor potential channel mediates circadian clock synchronization to low temperature cycles in Drosophila melanogaster.

    Science.gov (United States)

    Wolfgang, Werner; Simoni, Alekos; Gentile, Carla; Stanewsky, Ralf

    2013-10-07

    Circadian clocks are endogenous approximately 24 h oscillators that temporally regulate many physiological and behavioural processes. In order to be beneficial for the organism, these clocks must be synchronized with the environmental cycles on a daily basis. Both light : dark and the concomitant daily temperature cycles (TCs) function as Zeitgeber ('time giver') and efficiently entrain circadian clocks. The temperature receptors mediating this synchronization have not been identified. Transient receptor potential (TRP) channels function as thermo-receptors in animals, and here we show that the Pyrexia (Pyx) TRP channel mediates temperature synchronization in Drosophila melanogaster. Pyx is expressed in peripheral sensory organs (chordotonal organs), which previously have been implicated in temperature synchronization. Flies deficient for Pyx function fail to synchronize their behaviour to TCs in the lower range (16-20°C), and this deficit can be partially rescued by introducing a wild-type copy of the pyx gene. Synchronization to higher TCs is not affected, demonstrating a specific role for Pyx at lower temperatures. In addition, pyx mutants speed up their clock after being exposed to TCs. Our results identify the first TRP channel involved in temperature synchronization of circadian clocks.

  7. Identifying prospective antifouling coatings for venturis: Zeta potential measurements of oxides at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jayaweera, P.; Hettiarachchi, S.; Pound, B.G. (SRI International, Menlo Park, CA (United States))

    1992-10-01

    This report describes the results of research to determine the zeta potential of oxides responsible for fouling of heat transfer, venturi, and other flow measurement device surfaces. Fouling deposits formed on these surfaces reduce mass flow rates of water, causing power reductions of as much as 3 to 4%. There is considerable evidence that deposit formation can be prevented by coating the critical surfaces with a coating material that electrostatically repels the suspended fouling particulates. The zeta potential can be used as a parameter to identify and determine the best coating material to be employed for fouling prevention. The research entailed the development of the equipment necessary for zeta potential measurements, measurement of zeta potentials of oxides and coatings of interest to nuclear power plant applications, and evaluation of candidate coating materials to prevent fouling of surfaces. By this approach, numerous metals and oxides have been identified as potential coating materials. Fouling studies revealed that magnetite does not deposit on tungsten and palladium surfaces, indicating the potential use of these metals for coating venturi surfaces used in nuclear power plants.

  8. Potential Contributions of Heat Shock Proteins to Temperature-Dependent Sex Determination in the American Alligator

    Science.gov (United States)

    Kohno, S.; Katsu, Y.; Urushitani, H.; Ohta, Y.; Iguchi, T.; Guillette, L. J.

    2010-01-01

    Sex determination in the American alligator depends on the incubation temperature experienced during a thermo-sensitive period (TSP), although sex determination can be ‘reversed’ by embryonic exposure to an estrogenic compound. Thus, temperature and estrogenic signals play essential roles during temperature-dependent sex determination (TSD). The genetic basis for TSD is poorly understood, although previous studies observed that many of the genes associated with genetic sex determination (GSD) are expressed in species with TSD. Heat shock proteins (HSPs), good candidates because of their temperature-sensitive expression, have not been examined in regard to TSD but HSPs have the ability to modify steroid receptor function. A number of HSP cDNAs (HSP27, DNAJ, HSP40, HSP47, HSP60, HSP70A, HSP70B, HSP70C, HSP75, HSP90α, HSP90β, and HSP108) as well as cold-inducible RNA binding protein (CIRBP) and HSP-binding protein (HSPBP) were cloned, and expression of their mRNA in the gonadal-adrenal-mesonephros complex (GAM) was investigated. Embryonic and neonatal GAMs exhibited mRNA for all of the HSPs examined during and after the TSP. One-month-old GAMs were separated into 3 portions (gonad, adrenal gland, and mesonephros), and sexual dimorphism in the mRNA expression of gonadal HSP27 (male > female), gonadal HSP70A (male female) was observed. These findings provide new insights on TSD and suggest that further studies examining the role of HSPs during gonadal development are needed. PMID:19940440

  9. Low-temperature geothermal potential of the Ojo Caliente warm springs area, northern New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Vuataz, F.D.; Stix, J.; Goff, F.; Pearson, C.F.

    1984-05-01

    A detailed geochemical investigation of 17 waters (thermal and cold, mineralized and dilute) was performed in the Ojo Caliente-La Madera area. Two types of thermomineral waters have separate and distinctive geologic, geochemical, and geothermal characteristics. The water from Ojo Caliente Resort emerges with temperatures less than or equal to 54/sup 0/C from a Precambrian metarhyolite. Its chemistry, typically Na-HCO/sub 3/, has a total mineralization of 3600 mg/l. Isotopic studies have shown that the thermal water emerges from the springs and a hot well without significant mixing with the cold shallow aquifer of the valley alluvium. However, the cold aquifer adjacent to the resort does contain varying amounts of thermal water that originates from the warm spring system. Geothermometry calculations indicate that the thermal water may be as hot as 85/sup 0/C at depth before its ascent toward surface. Thermodynamic computations on the reaction states of numerous mineral phases suggest that the thermal water will not cause major scaling problems if the hot water is utilized for direct-use geothermal applications. By means of a network of very shallow holes, temperature and electrical conductivity anomalies have been found elsewhere in the valley around Ojo Caliente, and resistivity soundings have confirmed the presence of a plume of thermal water entering the shallow aquifer. The group of lukewarm springs around La Madera, with temperatures less than or equal to 29/sup 0/C, chemical type of NaCaMg-HCO/sub 3/Cl and with a total mineralization less than or equal to 1500 mg/l behaves as a different system without any apparent relation to the Ojo Caliente system. Its temperature at depth is not believed to exceed 35 to 40/sup 0/C.

  10. Ultra-High-Temperature-Ceramics: potentialities and barriers to the application in hot structures

    OpenAIRE

    Bellosi, Alida

    2009-01-01

    High performance Ultra-High-Temperature Composites (based on zirconium-, hafnium-, tantalum- borides and carbides) are characterized by relevant and unique thermo-physical and thermo-mechanical properties, suitable for applications in thermo-protection systems for aerospace applications. In spite of the difficult sinterability of borides and carbides of Zr, Hf, Ta, recent results highlighted that UHTC ceramics can be successfully produced with full density, fine and uniform microstructure and...

  11. Trichoderma spp.capable of growing at low temperatures with biocontrol potential

    Institute of Scientific and Technical Information of China (English)

    Szakacs G; Tavaszi A

    2004-01-01

    @@ Though there are successful commercial biocontrol products with Trichoderma spp. In many countries including US, Israel and Europe, their usefulness is limited in cold environments such as mid-and northern part of Europe, US and Canada, especially in the late fall, winter and early spring period.Trichoderma isolates capable of growing at low temperatures (5-10 ℃) and showing good antagonistic properties against plant pathogenic fungi may have therefore both scientific and commercial value.

  12. Bacterial population and biodegradation potential in chronically crude oil-contaminated marine sediments are strongly linked to temperature

    KAUST Repository

    Bargiela, Rafael

    2015-06-29

    Two of the largest crude oil-polluted areas in the world are the semi-enclosed Mediterranean and Red Seas, but the effect of chronic pollution remains incompletely understood on a large scale. We compared the influence of environmental and geographical constraints and anthropogenic forces (hydrocarbon input) on bacterial communities in eight geographically separated oil-polluted sites along the coastlines of the Mediterranean and Red Seas. The differences in community compositions and their biodegradation potential were primarily associated (P < 0.05) with both temperature and chemical diversity. Furthermore, we observed a link between temperature and chemical and biological diversity that was stronger in chronically polluted sites than in pristine ones where accidental oil spills occurred. We propose that low temperature increases bacterial richness while decreasing catabolic diversity and that chronic pollution promotes catabolic diversification. Our results further suggest that the bacterial populations in chronically polluted sites may respond more promptly in degrading petroleum after accidental oil spills.

  13. The potential of model studies for the understanding of catalyst poisoning and temperature effects in polymer electrolyte fuel cell reactions

    Science.gov (United States)

    Behm, R. J.; Jusys, Z.

    In this contribution we demonstrate the potential of model studies for the understanding of electrocatalytic reactions in low-temperature polymer electrolyte fuel cells (PEFCs) operated by H 2-rich anode feed gas, in particular of the role of temperature effects and catalyst poisoning. Reviewing previous work from our laboratory and, for better comparison, focussing on carbon-supported Pt catalysts, the important role of using fuel cell relevant reaction and mass transport conditions will be outlined. The latter conditions include continuous reaction, elevated temperatures, realistic supported catalyst materials and controlled mass transport. The data show the importance of combining electrochemical techniques such as rotating disc electrode (RDE), wall-jet and flow cell measurements, and on-line differential electrochemical mass spectrometry (DEMS) under controlled mass transport conditions.

  14. Low temperature photoluminescence of a nanostructured silicon-based semiconductor for potential applications

    Science.gov (United States)

    Raddenzati, A.; Hosatte, M.; Basta, M.; Kuznicki, Z. T.; Remouche, M.; Meyrueis, P.; Haeberlé, O.

    2016-05-01

    A nanoscale layer of amorphized silicon is obtained by implantations with silicon ions through a P-doped FZ-silicon wafer material few nanometers below the wafer surface. After a controlled annealing, the amorphized silicon material is sandwiched between two layers of recrystallized silicon. Defects remain at the interface c-Si/a-Si/c-Si. Photoluminescence at very low temperature is experimented to determine the energy levels generated by this design. TEM pictures show that some nanocrystalline elements are located close to the interface surrounded by a-Si. However, the photoluminescence spectra do not present any signal of luminescence from them. This could be due to random sizes of nanocrystals. Then, a scan from energies below the silicon bandgap has been realized at 8 K. The spectrum is composed of multiple narrow peaks close to the conduction band and a broadband from 0.78 eV to 1.05 eV. In order to determine the origin of these signals, spectra of three distinct peaks were collected at different temperatures from 8 K to 120 K. The broadband collapses more rapidly by increasing the temperature than the narrow lines and theirs maxima of intensity differ.

  15. Synthesis of low-moment CrVTiAl: A potential room temperature spin filter

    Science.gov (United States)

    Stephen, G. M.; McDonald, I.; Lejeune, B.; Lewis, L. H.; Heiman, D.

    2016-12-01

    The efficient production of spin-polarized currents at room temperature is fundamental to the advancement of spintronics. Spin-filter materials—semiconductors with unequal band gaps for each spin channel—can generate spin-polarized current without the need for spin-polarized contacts. In addition, a spin-filter material with zero magnetic moment would have the advantage of not producing strong fringing fields that would interfere with neighboring electronic components and limit the volume density of devices. The quaternary Heusler compound CrVTiAl has been predicted to be a zero-moment spin-filter material with a Curie temperature in excess of 1000 K. In this work, CrVTiAl has been synthesized with a lattice constant of a = 6.15 Å. Magnetization measurements reveal an exceptionally low moment of μ = 2.3 × 10-3 μB/f.u. at a field of μ0H = 2 T that is independent of temperature between T = 10 K and 400 K, consistent with the predicted zero-moment ferrimagnetism. Transport measurements reveal a combination of metallic and semiconducting components to the resistivity. Combining a zero-moment spin-filter material with nonmagnetic electrodes would lead to an essentially nonmagnetic spin injector. These results suggest that CrVTiAl is a promising candidate for further research in the field of spintronics.

  16. Advection of Potential Temperature in the Atmosphere of Irradiated Exoplanets: A Robust Mechanism to Explain Radius Inflation

    Science.gov (United States)

    Tremblin, P.; Chabrier, G.; Mayne, N. J.; Amundsen, D. S.; Baraffe, I.; Debras, F.; Drummond, B.; Manners, J.; Fromang, S.

    2017-01-01

    The anomalously large radii of strongly irradiated exoplanets have remained a major puzzle in astronomy. Based on a two-dimensional steady-state atmospheric circulation model, the validity of which is assessed by comparison to three-dimensional calculations, we reveal a new mechanism, namely the advection of the potential temperature due to mass and longitudinal momentum conservation, a process occurring in the Earth's atmosphere or oceans. In the deep atmosphere, the vanishing heating flux forces the atmospheric structure to converge to a hotter adiabat than the one obtained with 1D calculations, implying a larger radius for the planet. Not only do the calculations reproduce the observed radius of HD 209458b, but also reproduce the observed correlation between radius inflation and irradiation for transiting planets. Vertical advection of potential temperature induced by non-uniform atmospheric heating thus provides a robust mechanism to explain the inflated radii of irradiated hot Jupiters.

  17. The influence of chiral chemical potential, parallel electric and magnetic fields on the critical temperature of QCD

    CERN Document Server

    Ruggieri, M; Peng, G X

    2016-01-01

    We study the influence of external electric, $E$, and magnetic, $B$, fields parallel to each other, and of a chiral chemical potential, $\\mu_5$, on the chiral phase transition of Quantum Chromodynamics. Our theoretical framework is a Nambu-Jona-Lasinio model with a contact interaction. Within this model we compute the critical temperature of chiral symmetry restoration, $T_c$, as a function of the chiral chemical potential and field strengths. We find that the fields inhibit and $\\mu_5$ enhances chiral symmetry breaking, in agreement with previous studies.

  18. Pressure--volume--temperature properties of perfluorocyclobutane: equations of state, virial coefficients, and intermolecular potential energy functions

    Energy Technology Data Exchange (ETDEWEB)

    Douslin, D.R.; Moore, R.T.; Waddington, G.

    1959-11-01

    Studies of the pressure-volume-temperature properties of perfluorocyclobutane, in the ranges 3-394 atm and 30-350/sup 0/, yielded values of gas compressibility, critical constants, vapor pressure and orthobaric liquid and vapor densities. The results were correlated by the Beattie Bridgeman, Benedict Webb Rubin, and Martin-Hou equations of state and by the Stockmayer and the Kihara intermolecular potential energy functions. The merits of the several correlational methods are discussed.

  19. An improved potential energy surface and multi-temperature quasiclassical trajectory calculations of N2 + N2 dissociation reactions.

    Science.gov (United States)

    Bender, Jason D; Valentini, Paolo; Nompelis, Ioannis; Paukku, Yuliya; Varga, Zoltan; Truhlar, Donald G; Schwartzentruber, Thomas; Candler, Graham V

    2015-08-01

    Accurate modeling of high-temperature hypersonic flows in the atmosphere requires consideration of collision-induced dissociation of molecular species and energy transfer between the translational and internal modes of the gas molecules. Here, we describe a study of the N2 + N2⟶N2 + 2N and N2 + N2⟶4N nitrogen dissociation reactions using the quasiclassical trajectory (QCT) method. The simulations used a new potential energy surface for the N4 system; the surface is an improved version of one that was presented previously. In the QCT calculations, initial conditions were determined based on a two-temperature model that approximately separates the translational-rotational temperature from the vibrational temperature of the N2 diatoms. Five values from 8000 K to 30,000 K were considered for each of the two temperatures. Over 2.4 × 10(9) trajectories were calculated. We present results for ensemble-averaged dissociation rate constants as functions of the translational-rotational temperature T and the vibrational temperature T(v). The rate constant depends more strongly on T when T(v) is low, and it depends more strongly on T(v) when T is low. Quasibound reactant states contribute significantly to the rate constants, as do exchange processes at higher temperatures. We discuss two sets of runs in detail: an equilibrium test set in which T = T(v) and a nonequilibrium test set in which T(v) test set, high-v and moderately-low-j molecules contribute most significantly to the overall dissociation rate, and this state specificity becomes stronger as the temperature decreases. Dissociating trajectories tend to result in a major loss of vibrational energy and a minor loss of rotational energy. In the nonequilibrium test set, as T(v) decreases while T is fixed, higher-j molecules contribute more significantly to the dissociation rate, dissociating trajectories tend to result in a greater rotational energy loss, and the dissociation probability's dependence on v weakens. In

  20. An improved potential energy surface and multi-temperature quasiclassical trajectory calculations of N2 + N2 dissociation reactions

    Science.gov (United States)

    Bender, Jason D.; Valentini, Paolo; Nompelis, Ioannis; Paukku, Yuliya; Varga, Zoltan; Truhlar, Donald G.; Schwartzentruber, Thomas; Candler, Graham V.

    2015-08-01

    Accurate modeling of high-temperature hypersonic flows in the atmosphere requires consideration of collision-induced dissociation of molecular species and energy transfer between the translational and internal modes of the gas molecules. Here, we describe a study of the N2 + N2⟶N2 + 2N and N2 + N2⟶4N nitrogen dissociation reactions using the quasiclassical trajectory (QCT) method. The simulations used a new potential energy surface for the N4 system; the surface is an improved version of one that was presented previously. In the QCT calculations, initial conditions were determined based on a two-temperature model that approximately separates the translational-rotational temperature from the vibrational temperature of the N2 diatoms. Five values from 8000 K to 30 000 K were considered for each of the two temperatures. Over 2.4 × 109 trajectories were calculated. We present results for ensemble-averaged dissociation rate constants as functions of the translational-rotational temperature T and the vibrational temperature Tv. The rate constant depends more strongly on T when Tv is low, and it depends more strongly on Tv when T is low. Quasibound reactant states contribute significantly to the rate constants, as do exchange processes at higher temperatures. We discuss two sets of runs in detail: an equilibrium test set in which T = Tv and a nonequilibrium test set in which Tv rate, and this state specificity becomes stronger as the temperature decreases. Dissociating trajectories tend to result in a major loss of vibrational energy and a minor loss of rotational energy. In the nonequilibrium test set, as Tv decreases while T is fixed, higher-j molecules contribute more significantly to the dissociation rate, dissociating trajectories tend to result in a greater rotational energy loss, and the dissociation probability's dependence on v weakens. In this way, as Tv decreases, rotational energy appears to compensate for the decline in average vibrational energy in

  1. Scalar O(N) Model at Finite Temperature -- 2PI Effective Potential in Different Approximations

    CERN Document Server

    Baacke, J; Baacke, Jurgen; Michalski, Stefan

    2004-01-01

    We calculate the two-particle irreducible (2PI) effective potential of the O(N) linear sigma model in 1+1 dimensions. The approximations we use are the next-to-leading order of a 1/N expansion (for arbitrary N) and a kind of "resummed loop approximation" for N=1. We show that the effective potential of the 1/N expansion is convex for N=4 and N=10 whereas it is not for the "loop" expansion and the case N=1 of the 1/N expansion.

  2. Potential Arctic tundra vegetation shifts in response to changing temperature, precipitation and permafrost thaw

    Science.gov (United States)

    van der Kolk, Henk-Jan; Heijmans, Monique M. P. D.; van Huissteden, Jacobus; Pullens, Jeroen W. M.; Berendse, Frank

    2016-11-01

    Over the past decades, vegetation and climate have changed significantly in the Arctic. Deciduous shrub cover is often assumed to expand in tundra landscapes, but more frequent abrupt permafrost thaw resulting in formation of thaw ponds could lead to vegetation shifts towards graminoid-dominated wetland. Which factors drive vegetation changes in the tundra ecosystem are still not sufficiently clear. In this study, the dynamic tundra vegetation model, NUCOM-tundra (NUtrient and COMpetition), was used to evaluate the consequences of climate change scenarios of warming and increasing precipitation for future tundra vegetation change. The model includes three plant functional types (moss, graminoids and shrubs), carbon and nitrogen cycling, water and permafrost dynamics and a simple thaw pond module. Climate scenario simulations were performed for 16 combinations of temperature and precipitation increases in five vegetation types representing a gradient from dry shrub-dominated to moist mixed and wet graminoid-dominated sites. Vegetation composition dynamics in currently mixed vegetation sites were dependent on both temperature and precipitation changes, with warming favouring shrub dominance and increased precipitation favouring graminoid abundance. Climate change simulations based on greenhouse gas emission scenarios in which temperature and precipitation increases were combined showed increases in biomass of both graminoids and shrubs, with graminoids increasing in abundance. The simulations suggest that shrub growth can be limited by very wet soil conditions and low nutrient supply, whereas graminoids have the advantage of being able to grow in a wide range of soil moisture conditions and have access to nutrients in deeper soil layers. Abrupt permafrost thaw initiating thaw pond formation led to complete domination of graminoids. However, due to increased drainage, shrubs could profit from such changes in adjacent areas. Both climate and thaw pond formation

  3. Temperature-Responsive Gelation of Type I Collagen Solutions Involving Fibril Formation and Genipin Crosslinking as a Potential Injectable Hydrogel

    Directory of Open Access Journals (Sweden)

    Shunji Yunoki

    2013-01-01

    Full Text Available We investigated the temperature-responsive gelation of collagen/genipin solutions using pepsin-solubilized collagen (PSC and acid-solubilized collagen (ASC as substrates. Gelation occurred in the PSC/genipin solutions at genipin concentrations 0–2 mM under moderate change in temperature from 25 to 37°C. The PSC/genipin solutions exhibited fluidity at room temperature for at least 30 min, whereas the ASC/genipin solutions rapidly reached gel points. In specific cases PSC would be preferred over ASC as an injectable gel system. The temperature-responsive gelation of PSC/genipin solutions was due to temperature responses to genipin crosslinking and collagen fibril formation. The elastic modulus of the 0.5% PSC/genipin gel system could be adjusted in a range of 2.5 to 50 kPa by the PSC and genipin concentrations, suggesting that a PSC/genipin solution is a potential injectable gel system for drug and cell carriers, with mechanical properties matching those of living tissues.

  4. The potential to supply low temperature district heating to existing building area

    DEFF Research Database (Denmark)

    Li, Hongwei; Svendsen, Svend

    2013-01-01

    Low-temperature district heating (LTDH) has the advantages as reduced network heat loss, improved quality match between energy supply and energy demand, and increased utilization of low-grade waste heat and renewable energy. The LTDH represents the next generation district heating (DH) system....... The use of LTDH for low energy buildings was demonstrated through pilot projects carried out in Denmark. However, the majority of the buildings were built during the time when there had little requirement for building energy conservation. In order to implement the LTDH in a large scale, its feasibility...

  5. Potential Usage of Thermoelectric Devices in a High Temperature PEM Fuel Cell System

    DEFF Research Database (Denmark)

    Xin, Gao; Chen, Min; Andreasen, Søren Juhl

    2012-01-01

    Methanol fuelled high temperature polymer electrolyte membrane fuel cell (HTPEMFC) power systems are promising as the next generation of vehicle engines, efficient and environmentally friendly. Currently, their performance still needs to be improved and they still rely on a large Li-ion battery......-difference model is then employed and two main parameters are identified. Secondly, TE coolers are integrated into the methanol steam reformer to regulate heat fluxes herein and improve the system dynamic performance. Similar modification is also done on the evaporator to improve its dynamic performance as well...

  6. Chlorella mirabilis as a potential species for biomass production in low temperature environment

    Directory of Open Access Journals (Sweden)

    Satya Prakash Shukla

    2013-04-01

    Full Text Available Successful adaptation/acclimatization to low temperatures in micro-algae is usually connected with production of specific biotechnologically important compounds. In this study, we evaluated the growth characteristics in a micro-scale mass cultivation of the Antarctic soil green alga Chlorella mirabilis under different nitrogen and carbon sources followed by analyses of fatty acid contents. The micro-scale mass cultivation was performed in stable (in-door and variable (out-door conditions during winter and/or early spring in the Czech Republic. In the in-door cultivation, the treatments for nitrogen and carbon sources determination included pure Z medium (control, Z, Z medium + 5% glycerol (ZG, Z medium + 5% glycerol + 50 µM KNO3 (ZGN, Z medium + 5% glycerol + 200µM NH4Cl (ZGA, Z medium + 5% glycerol + 1 mM Na2CO3 (ZNC, Z medium + 5% glycerol + 1 mM Na2CO3 + 200µM NH4Cl (ZGCA and Z medium + 5% glycerol + 1 mM Na2CO3 + 50 µM KNO3 (ZGCN and were performed at 15°C with an irradiance of 75 µmol m-2 s-1. During the out-door experiments, the night-day temperature ranged from -6.6°C to 17.5°C (daily average 3.1±5.3 °C and irradiance ranged from 0 to 2300 µmol m-2 s-1 (daily average 1500±1090 µmol m-2 s-1. Only the Z, ZG, ZGN and ZGC treatments were used in the out-door cultivation. In the in-door mass cultivation, all nitrogen and carbon sources additions increased the growth rate with the exception of ZGA. When individual sources were considered, only the effect of 5% glycerol addition was significant. On the other hand, the growth rate decreased in the ZG and ZGN treatments in the out-door experiment, probably due to carbon limitation. Fatty acid composition showed increased production of linoleic acid in the glycerol treatments. The studied strain of C. mirabilis is proposed to be a promising source of linoleic acid in low temperature mass cultivation biotechnology. This strain is a perspective model organism for biotechnology in low-temperature

  7. Pseudo-Potentials in Dense and He-like Hot temperature Plasmas

    Science.gov (United States)

    Deutsch, Claude; Rahal, Hamid

    2012-10-01

    Extending our former derivations in dense and high temperature plasmas of hydrogenic effective interactions mimiking the Heisenberg uncertainty principle [1,2], we worked out in a canonical ensemble, effective interactions in He-like plasmas where an orbital 1s electron remains strongly tighted to the He-like ions. The plasma electrons are then taken into account through appropriate Slater sums obtained in the most economical hydrogenic extension of the He-like bound and scattered states with angular orbital momentum lClementi and C. Roetti, Atomic Data and Nucl. Data Tables, 14,177(1974)

  8. Potential Usage of Thermoelectric Devices in a High Temperature PEM Fuel Cell System

    DEFF Research Database (Denmark)

    Xin, Gao; Chen, Min; Andreasen, Søren Juhl

    2012-01-01

    -liquid heat exchanger to jointly form a heat recovery subsystem for electricity production. It is calculated that the recovered power can increase the system efficiency and mitigate the dependence on Li-ion battery during system startup. To further improve the TEG subsystem performance, a finite......Methanol fuelled high temperature polymer electrolyte membrane fuel cell (HTPEMFC) power systems are promising as the next generation of vehicle engines, efficient and environmentally friendly. Currently, their performance still needs to be improved and they still rely on a large Li-ion battery...

  9. Laboratory determined suction potential of Topopah Spring tuff at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Daily, W.; Lin, Wunan

    1991-01-01

    The purpose of this work is to experimentally determine the capillary suction potential of Topopah Spring tuff from Yucca Mountain, Nye County, Nevada. This data can be used to help characterize the unsaturated hydraulic properties of the densely welded tuff at this site. 7 refs., 4 figs., 1 tab.

  10. Effect of SRT and temperature on biological conversions and the related scum-forming potential

    NARCIS (Netherlands)

    Halalsheh, M.M.I.; Koppes, J.; Elzen, den J.; Zeeman, G.; Fayyad, M.; Lettinga, G.

    2005-01-01

    Sludge flotation was reported to cause several operational problems in anaerobic systems including UASB reactors treating both strong domestic sewage and some industrial wastewater. This research is to investigate the effect of anaerobic digestion on scum-forming potential (SFP) of sludge and other

  11. The effect of temperature, interaction range, and pair potential on the formation of dodecagonal quasicrystals in core-corona systems

    Science.gov (United States)

    Pattabhiraman, Harini; Dijkstra, Marjolein

    2017-03-01

    A two-dimensional dodecagonal quasicrystal was previously reported by Dotera et al (2014 Nature 506 208) in a system of particles interacting with a hard core of diameter σ and a repulsive square shoulder of diameter δ =1.40σ . In the current work, we examine the formation of this quasicrystal using bond orientational order parameters, correlation functions and tiling distributions. We find that this dodecagonal quasicrystal forms from a fluid phase. We further study the effect of the width of the repulsive shoulder by simulating the system over a range of values of δ. For the range of densities and temperatures considered, we observe the formation of the dodecagonal quasicrystal between δ =1.30σ and 1.44σ . We also study the effect of shape of the interaction potential by simulating the system using three other interaction potentials with two length scales, namely hard-core plus a linear ramp, modified exponential, or Buckingham (exp-6) potential. We observe the presence of the quasicrystal in all three systems. However, depending on the shape of the potential, the formation of the quasicrystal takes place at lower temperatures (or higher interaction strengths). Using free-energy calculations, we demonstrate that the quasicrystal is thermodynamically stable in the square-shoulder and linear-ramp system.

  12. Electrostatic Potential in High-Temperature Superconducting Cuprates: Extended Ginzburg-Landau Theory

    Directory of Open Access Journals (Sweden)

    Madhuparna Karmakar

    2011-01-01

    Full Text Available The electrostatic potential and the associated charge distribution in the vortices of high- superconductors involving mixed symmetry state of the order parameters have been studied. The work is carried out in the framework of an extended Ginzburg-Landau (GL theory involving the Gorter-Casimir two-fluid model and Bardeen's extension of GL theory applied to the high- superconductors. The properties are calculated using the material parameters relevant for the high- cuprate YBCO.

  13. A new method to study lattice QCD at finite temperature and chemical potential

    CERN Document Server

    Fodor, Z

    2002-01-01

    Due to the sign problem, it is exponentially difficult to study QCD on the lattice at finite chemical potential. In this letter we propose a method --an overlap ensuring multi-parameter reweighting technique-- to solve the problem. We apply this method and give the phase diagram of four-flavor QCD obtained on lattices 4^4 and 4\\cdot6^3. Our results are based on {\\cal{O}}(10^3-10^4) configurations.

  14. Low-temperature thermal properties from the EU testing program for potential ITER insulation

    Energy Technology Data Exchange (ETDEWEB)

    Broadbent, A.J.; Crozier, J.; Smith, K.D. [Oxford Instruments Special Projects, Oxon (United Kingdom)] [and others

    1997-06-01

    Insulation systems will be a key element in the future construction and impregnation of the coils for the ITER device. The thermal contraction and thermal conductivity of ten different electrical insulation systems are measured at temperatures from 4 K to 300 K. Several insulation systems incorporate an electrical barrier layer. The insulation systems are all based on identical S2-glass with various epoxy resins, some of which are not believed to have been previously used in superconducting coils. In particular resins with a high functionality are investigated, some of which are suitable for Vacuum Pressure Impregnation (VPI). The final results of this program are presented and compared to the results from a benchmark testing program (insulation system based on anhydride cured DGEBA resin and S2 glass). This work is financed by the EU under NET contract ERB 5000 940023 (NET 93-857) within the framework of MR.

  15. Effects of temperature on decomposition of a potential nuisance species: the submerged aquatic macrophyte Egeria najas planchom (Hydrocharitaceae

    Directory of Open Access Journals (Sweden)

    P Carvalho

    Full Text Available Decomposition of aquatic plants is influenced by several biotic and abiotic factors. Among them, temperature plays an important role. Despite the increasing number of studies describing the effects of temperature on the decomposition of aquatic macrophytes, little attention has been given to the decay of submerged macrophytes. In this paper, we assessed the effect of temperature on weight loss and chemical composition of detritus of the submerged aquatic macrophyte Egeria najas Planchon (Hydrocharitaceae. Fresh plant material was maintained at 17ºC and 27ºC, in the dark, in incubation chambers. The overall decay process was best described by a linear model, with rates of 0.014 day-1 (R² = 94% and 0.045 day-1 (R² = 96% obtained at 17ºC and 27ºC, respectively. The analysis of covariance (ANCOVA indicated a significant difference between the decomposition rates at the two temperatures. The rapid breakdown of E. najas detritus, indicated by the decay coefficient, may be explained by its low content of resistant compounds such as cellulose and lignin. The variables analyzed in this study (pH, electrical conductivity, dissolved oxygen in the water and organic matter, total nitrogen and total phosphorus concentration in detritus showed accentuated responses at 27ºC. It is likely that the higher temperature increased microbial activity and, therefore, oxygen consumption in the water, consequently affecting the pH and the rate of ion and nutrient liberation into the aquatic ecosystem. Due to the rapid decomposition of E. najas at high temperatures, a small exportation is expected of this species from its stands to distant regions in tropical reservoirs, where it is considered a potential nuisance species.

  16. Albedo and land surface temperature shift in hydrocarbon seepage potential area, case study in Miri Sarawak Malaysia

    Science.gov (United States)

    Suherman, A.; Rahman, M. Z. A.; Busu, I.

    2014-02-01

    The presence of hydrocarbon seepage is generally associated with rock or mineral alteration product exposures, and changes of soil properties which manifest with bare development and stress vegetation. This alters the surface thermodynamic properties, changes the energy balance related to the surface reflection, absorption and emission, and leads to shift in albedo and LST. Those phenomena may provide a guide for seepage detection which can be recognized inexpensively by remote sensing method. District of Miri is used for study area. Available topographic maps of Miri and LANDSAT ETM+ were used for boundary construction and determination albedo and LST. Three land use classification methods, namely fixed, supervised and NDVI base classifications were employed for this study. By the intensive land use classification and corresponding statistical comparison was found a clearly shift on albedo and land surface temperature between internal and external seepage potential area. The shift shows a regular pattern related to vegetation density or NDVI value. In the low vegetation density or low NDVI value, albedo of internal area turned to lower value than external area. Conversely in the high vegetation density or high NDVI value, albedo of internal area turned to higher value than external area. Land surface temperature of internal seepage potential was generally shifted to higher value than external area in all of land use classes. In dense vegetation area tend to shift the temperature more than poor vegetation area.

  17. The sympathetic nervous system is controlled by transient receptor potential vanilloid 1 in the regulation of body temperature.

    Science.gov (United States)

    Alawi, Khadija M; Aubdool, Aisah A; Liang, Lihuan; Wilde, Elena; Vepa, Abhinav; Psefteli, Maria-Paraskevi; Brain, Susan D; Keeble, Julie E

    2015-10-01

    Transient receptor potential vanilloid 1 (TRPV1) is involved in sensory nerve nociceptive signaling. Recently, it has been discovered that TRPV1 receptors also regulate basal body temperature in multiple species from mice to humans. In the present study, we investigated whether TRPV1 modulates basal sympathetic nervous system (SNS) activity. C57BL6/J wild-type (WT) mice and TRPV1 knockout (KO) mice were implanted with radiotelemetry probes for measurement of core body temperature. AMG9810 (50 mg/kg) or vehicle (2% DMSO/5% Tween 80/10 ml/kg saline) was injected intraperitoneally. Adrenoceptor antagonists or vehicle (5 ml/kg saline) was injected subcutaneously. In WT mice, the TRPV1 antagonist, AMG9810, caused significant hyperthermia, associated with increased noradrenaline concentrations in brown adipose tissue. The hyperthermia was significantly attenuated by the β-adrenoceptor antagonist propranolol, the mixed α-/β-adrenoceptor antagonist labetalol, and the α1-adrenoceptor antagonist prazosin. TRPV1 KO mice have a normal basal body temperature, indicative of developmental compensation. d-Amphetamine (potent sympathomimetic) caused hyperthermia in WT mice, which was reduced in TRPV1 KO mice, suggesting a decreased sympathetic drive in KOs. This study provides new evidence that TRPV1 controls thermoregulation upstream of the SNS, providing a potential therapeutic target for sympathetic hyperactivity thermoregulatory disorders. © FASEB.

  18. Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

    2007-01-01

    , the internal sulphidation is much more significant than that revealed in the demonstration project. Avedøre 2 main boiler is fuelled with wood pellets + heavy fuel oil + gas. Some reaction products due to the presence of vanadium compounds in the heavy oil were detected, i.e. iron vanadates. However, the most...... significant corrosion attack was due to sulphidation attack at the grain boundaries of 18-8 steel after 3 years exposure. The corrosion mechanisms and corrosion rates are compared with biomass firing and coal firing. Potential corrosion problems due to co-firing biomass and fossil fuels are discussed....

  19. Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

    2008-01-01

    in this environment, the internal sulphidation is much more significant than that revealed in the demonstration project. Avedøre 2 main boiler is fuelled with wood pelletsþheavy fuel oilþgas. Some reaction products resulting from the presence of vanadium compounds in the heavy oil were detected, i.e. iron vanadates....... However, the most significant corrosion attack was sulphidation attack at the grain boundaries of 18-8 steel after 3 years exposure. The corrosion mechanisms and corrosion rates are compared with biomass firing and coal firing. Potential corrosion problems due to co-firing biomass and fossil fuels...

  20. Pharmacology of modality-specific transient receptor potential vanilloid-1 antagonists that do not alter body temperature.

    Science.gov (United States)

    Reilly, Regina M; McDonald, Heath A; Puttfarcken, Pamela S; Joshi, Shailen K; Lewis, LaGeisha; Pai, Madhavi; Franklin, Pamela H; Segreti, Jason A; Neelands, Torben R; Han, Ping; Chen, Jun; Mantyh, Patrick W; Ghilardi, Joseph R; Turner, Teresa M; Voight, Eric A; Daanen, Jerome F; Schmidt, Robert G; Gomtsyan, Arthur; Kort, Michael E; Faltynek, Connie R; Kym, Philip R

    2012-08-01

    The transient receptor potential vanilloid-1 (TRPV1) channel is involved in the development and maintenance of pain and participates in the regulation of temperature. The channel is activated by diverse agents, including capsaicin, noxious heat (≥ 43°C), acidic pH (temperature antagonists representing multiple TRPV1 pharmacophores were evaluated at recombinant rat and human TRPV1 channels with Ca(2+) flux assays, and two classes of antagonists were identified based on their differential ability to inhibit acid activation. Although both classes of antagonists completely blocked capsaicin- and NADA-induced activation of TRPV1, select compounds only partially inhibited activation of the channel by protons. Electrophysiology and calcitonin gene-related peptide release studies confirmed the differential pharmacology of these antagonists at native TRPV1 channels in the rat. Comparison of the in vitro pharmacological properties of these TRPV1 antagonists with their in vivo effects on core body temperature confirms and expands earlier observations that acid-sparing TRPV1 antagonists do not significantly increase core body temperature. Although both classes of compounds elicit equivalent analgesia in a rat model of knee joint pain, the acid-sparing antagonist tested is not effective in a mouse model of bone cancer pain.

  1. Oxygen Vacancy Induced Room-Temperature Metal-Insulator Transition in Nickelate Films and Its Potential Application in Photovoltaics.

    Science.gov (United States)

    Wang, Le; Dash, Sibashisa; Chang, Lei; You, Lu; Feng, Yaqing; He, Xu; Jin, Kui-juan; Zhou, Yang; Ong, Hock Guan; Ren, Peng; Wang, Shiwei; Chen, Lang; Wang, Junling

    2016-04-20

    Oxygen vacancy is intrinsically coupled with magnetic, electronic, and transport properties of transition-metal oxide materials and directly determines their multifunctionality. Here, we demonstrate reversible control of oxygen content by postannealing at temperature lower than 300 °C and realize the reversible metal-insulator transition in epitaxial NdNiO₃ films. Importantly, over 6 orders of magnitude in the resistance modulation and a large change in optical bandgap are demonstrated at room temperature without destroying the parent framework and changing the p-type conductive mechanism. Further study revealed that oxygen vacancies stabilized the insulating phase at room temperature is universal for perovskite nickelate films. Acting as electron donors, oxygen vacancies not only stabilize the insulating phase at room temperature, but also induce a large magnetization of ∼50 emu/cm³ due to the formation of strongly correlated Ni²⁺ t(2g)⁶e(g)² states. The bandgap opening is an order of magnitude larger than that of the thermally driven metal-insulator transition and continuously tunable. Potential application of the newly found insulating phase in photovoltaics has been demonstrated in the nickelate-based heterojunctions. Our discovery opens up new possibilities for strongly correlated perovskite nickelates.

  2. Temperature-sensitive polymer-coated magnetic nanoparticles as a potential drug delivery system for targeted therapy of thyroid cancer.

    Science.gov (United States)

    Koppolu, Bhanuprasanth; Bhavsar, Zarna; Wadajkar, Aniket S; Nattama, Sivaniarvindpriya; Rahimi, Maham; Nwariaku, Fiemu; Nguyen, Kytai T

    2012-12-01

    The objective of this work was to develop and investigate temperature-sensitive poly(N-isopropylacrylamide-acrylamide-allylamine)-coated iron oxide magnetic nanoparticles (TPMNPs) as possible targeted drug carriers for treatments of advanced thyroid cancer (ATC). These nanoparticles were prepared by free radical polymerization of monomers on the surface of silane-coupled iron oxide nanoparticles. In vitro studies demonstrated that TPMNPs were cytocompatible and effectively taken up by cancer cells in a dose-dependent manner. An external magnetic field significantly increased nanoparticle uptake, especially when cells were exposed to physiological flow conditions. Drug loading and release studies using doxorubicin confirmed the temperature-responsive release of drugs from nanoparticles. In addition, doxorubicin-loaded nanoparticles significantly killed ATC cells when compared to free doxorubicin. The in vitro results indicate that TPMNPs have potential as targeted and controlled drug carriers for thyroid cancer treatment.

  3. One-loop omega-potential of charged massive fields in a constant homogeneous magnetic field at high temperatures

    CERN Document Server

    Kalinichenko, I S

    2016-01-01

    The explicit expressions for the high-temperature expansions of the one-loop corrections to the omega-potential coming from the charged scalar and Dirac particles and, separately, from antiparticles in a constant homogeneous magnetic field are derived. The explicit expressions for the non-perturbative corrections to the effective action at finite temperature and density are obtained. The thermodynamic properties of a gas of charged scalars in a constant homogeneous magnetic field are analyzed in the one-loop approximation. It turns out that, in this approximation, the system suffers the first order phase transition from the diamagnetic to the superconducting state at sufficiently high densities. The improvement of the one-loop result by summing the ring diagrams is investigated. This improvement leads to a drastic change of the thermodynamic properties of the system. The gas of charged scalars passes to the ferromagnetic state in place of the superconducting one at high densities and sufficiently low temperat...

  4. Preparation of Ultrahigh Potential Gradient of ZnO Varistors by Rare-Earth Doping and Low-Temperature Sintering

    Directory of Open Access Journals (Sweden)

    Lei Ke

    2013-01-01

    Full Text Available The effects of rare-earth doping and low-temperature sintering on electrical properties of ZnO varistors were investigated. The potential gradient (E1mA of the ZnO varistors increased significantly to 2247.2 V/mm after doping 0.08 mol% of Y2O3 and sintering at 800°C for 2 h. The notable decrease of the grain size with the given experimental conditions was the origin for the increase in E1mA. During the process of high-temperature sintering, both the oxygen at the grain boundary interface and the neutralisation of the ions on the depletion layer were directly reduced, which caused the weight loss and the internal derangement of double Schottky barriers.

  5. Phylogenetic and Functional Analysis of Metagenome Sequence from High-Temperature Archaeal Habitats Demonstrate Linkages between Metabolic Potential and Geochemistry

    DEFF Research Database (Denmark)

    Inskeep, William P; Jay, Zackary J; Herrgard, Markus;

    2013-01-01

    Geothermal habitats in Yellowstone National Park (YNP) provide an unparalleled opportunity to understand the environmental factors that control the distribution of archaea in thermal habitats. Here we describe, analyze, and synthesize metagenomic and geochemical data collected from seven high......-temperature sites that contain microbial communities dominated by archaea relative to bacteria. The specific objectives of the study were to use metagenome sequencing to determine the structure and functional capacity of thermophilic archaeal-dominated microbial communities across a pH range from 2.5 to 6.......4 and to discuss specific examples where the metabolic potential correlated with measured environmental parameters and geochemical processes occurring in situ. Random shotgun metagenome sequence (∼40-45 Mb Sanger sequencing per site) was obtained from environmental DNA extracted from high-temperature sediments and...

  6. Nontoxic and abundant copper zinc tin sulfide nanocrystals for potential high-temperature thermoelectric energy harvesting.

    Science.gov (United States)

    Yang, Haoran; Jauregui, Luis A; Zhang, Genqiang; Chen, Yong P; Wu, Yue

    2012-02-01

    Improving energy/fuel efficiency by converting waste heat into electricity using thermoelectric materials is of great interest due to its simplicity and reliability. However, many thermoelectric materials are composed of either toxic or scarce elements. Here, we report the experimental realization of using nontoxic and abundant copper zinc tin sulfide (CZTS) nanocrystals for potential thermoelectric applications. The CZTS nanocrystals can be synthesized in large quantities from solution phase reaction and compressed into robust bulk pellets through spark plasma sintering and hot press while still maintaining nanoscale grain size inside. Electrical and thermal measurements have been performed from 300 to 700 K to understand the electron and phonon transports. Extra copper doping during the nanocrystal synthesis introduces a significant improvement in the performance.

  7. Annual variations and effects of temperature on Legionella spp. and other potential opportunistic pathogens in a bathroom.

    Science.gov (United States)

    Lu, Jingrang; Buse, Helen; Struewing, Ian; Zhao, Amy; Lytle, Darren; Ashbolt, Nicholas

    2017-01-01

    Opportunistic pathogens (OPs) in drinking water, like Legionella spp., mycobacteria, Pseudomonas aeruginosa, and free-living amobae (FLA) are a risk to human health, due to their post-treatment growth in water systems. To assess and manage these risks, it is necessary to understand their variations and environmental conditions for the water routinely used. We sampled premise tap (N cold = 26, N hot = 26) and shower (N shower = 26) waters in a bathroom and compared water temperatures to levels of OPs via qPCR and identified Legionella spp. by 16S ribosomal RNA (rRNA) gene sequencing. The overall occurrence and cell equivalent quantities (CE L(-1)) of Mycobacterium spp. were highest (100 %, 1.4 × 10(5)), followed by Vermamoeba vermiformis (91 %, 493), Legionella spp. (59 %, 146), P. aeruginosa (14 %, 10), and Acanthamoeba spp. (5 %, 6). There were significant variations of OP's occurrence and quantities, and water temperatures were associated with their variations, especially for Mycobacterium spp., Legionella spp., and V. vermiformis. The peaks observed for Legionella, mainly consisted of Legionella pneumophila sg1 or Legionella anisa, occurred in the temperature ranged from 19 to 49 °C, while Mycobacterium spp. and V. vermiformis not only co-occurred with Legionella spp. but also trended to increase with increasing temperatures. There were higher densities of Mycobacterium in first than second draw water samples, indicating their release from faucet/showerhead biofilm. Legionella spp. were mostly at detectable levels and mainly consisted of L. pneumophila, L. anisa, Legionella donaldsonii, Legionella tunisiensis, and an unknown drinking water isolate based on sequence analysis. Results from this study suggested potential health risks caused by opportunistic pathogens when exposed to warm shower water with low chlorine residue and the use of Mycobacterium spp. as an indicator of premise pipe biofilm and the control management of those potential

  8. Multidecadal variability of potential temperature, salinity, and transport in the eastern subpolar North Atlantic

    Science.gov (United States)

    Holliday, N. P.; Cunningham, S. A.; Johnson, C.; Gary, S. F.; Griffiths, C.; Read, J. F.; Sherwin, T.

    2015-09-01

    The Extended Ellett Line (EEL) hydrographic section extends from Scotland to Iceland crossing the Rockall Trough, Hatton-Rockall Basin, and Iceland Basin. With 61 full-depth stations at a horizontal resolution of 10-50 km, the EEL samples the upper limb of the Atlantic Meridional Overturning Circulation flowing across the Iceland-Scotland Ridge into the Nordic Seas. The Rockall Trough has been sampled nearly four times per year from 1975 to 1996, and the full section annually since 1996. The EEL is an exceptionally long-time series of deep ocean temperatures and salinities. This study extends prior work in the Rockall Trough, and examines for the first time 18 year records in the Iceland and Hatton-Rockall Basins. We quantify errors in the time series from two sources: observational errors and aliasing. The data quality and annual sampling are suitable for observing interannual to decadal variability because the variability exceeds our error estimates. The upper waters of all three basins are cooler/fresher from 1997 to 2001, warmer/more saline 2001-2006, and cooler/fresher from 2006 to 2014. A reference level for geostrophic shear is developed heuristically and by comparison with sea-surface altimetry. The mean northward transport in the upper waters is 6.7 ± 3.7 Sv and there is a 6.1 ± 2.5 Sv southward flow below the thermocline. Although the magnitude of the Iceland Basin overturning circulation (4.3 ± 1.9 Sv) is greater than in the Rockall Trough (3.0 ± 3.7 Sv), the variability is greater in the Rockall Trough. We discuss the results in the context of our understanding of drivers of variability.

  9. Pyrolysis of oil at high temperatures: Gas potentials, chemical and carbon isotopic signatures

    Institute of Scientific and Technical Information of China (English)

    TIAN Hui; XIAO XianMing; YANG LiGuo; XIAO ZhongYao; GUO LiGuo; SHEN JiaGui; LU YuHong

    2009-01-01

    Although the gas cracked from oil has been believed to be one of the important sources in highly ma-tured marine basins, there are still some debates on its resource potentials and chemical and isotopic compositions. In this study a Cambrian-sourced marine oil sample from the Silurian reservoir of well TZ62 in the central Tarim basin was pyrolyzed using sealed gold tubes with two different pyrolysis schemes: continuous pyrolysis in a closed system and stepwise semi-open pyrolysis. The results show that the maximum weight yield of C1-5 gases occurs at EasyRo=2.3% and the residual gas poten-tial after this maturity is only 43.4 mL/g, about 12% of the yield of 361 mL/g at EasyRo=2.3%. Combined with the results of kinetic modeling, the main stage of gas generation from oil cracking is believed within the EasyRo=1.6%-2.3%. The increase in the volume yield of C1-5 gases at EasyRo2.3% in a closed system is mainly related to the re-cracking of previously formed C2-5 wet gases, not the direct cracking of oil. The stepwise pyrolysis experiments show that the gas from the cracking of residual oil at EasyRo2.3% is characterized by very high dryness index (higher than 92%) and heavy methane carbon isotopes ranging from -28.7‰ to -26.7‰, which is quite different from the gases from the con-tinuous pyrolysis in a closed system. The kinetic modeling of methane carbon isotope fractionation shows that the carbon isotopes of methane within the main stage of gas generation (EasyRo<2.3%) are far lighter than the carbon isotopes of the precursor oils under a geological heating rate of 2℃/Ma. The above observations and results provide some new clues to the accurate recognition and objective re-source evaluation of oil cracking gas in highly mature marine basins.

  10. The potential future of high-temperature gas turbines in power plants; Zukunftsperspektiven fuer die Hochtemperatur-Gasturbine im Kraftwerksbau

    Energy Technology Data Exchange (ETDEWEB)

    Vogeler, Konrad [Technische Univ. Dresden (Germany). Inst. fuer Stroemungsmechanik

    2011-07-01

    The future role of the high-temperature gas turbine is discussed. Due to environmental and cost pressure, the mix of primary energy sources will be changing. CO{sub 2} capture and storage (CCS) will have major impact on technical equipment and operation cost of fossil-fired power plants. If fuel consumption has to be minimised, the efficiency of power plants will be the key to success. The paper discusses the main parameters which influence efficiency and power output for an open and combined cycle gas turbine cycle. State-of-the-art materials and manufacturing methods promise potentials to increase efficiency even further. (orig.)

  11. The complete genome and proteome of Laribacter hongkongensis reveal potential mechanisms for adaptations to different temperatures and habitats.

    Directory of Open Access Journals (Sweden)

    Patrick C Y Woo

    2009-03-01

    Full Text Available Laribacter hongkongensis is a newly discovered Gram-negative bacillus of the Neisseriaceae family associated with freshwater fish-borne gastroenteritis and traveler's diarrhea. The complete genome sequence of L. hongkongensis HLHK9, recovered from an immunocompetent patient with severe gastroenteritis, consists of a 3,169-kb chromosome with G+C content of 62.35%. Genome analysis reveals different mechanisms potentially important for its adaptation to diverse habitats of human and freshwater fish intestines and freshwater environments. The gene contents support its phenotypic properties and suggest that amino acids and fatty acids can be used as carbon sources. The extensive variety of transporters, including multidrug efflux and heavy metal transporters as well as genes involved in chemotaxis, may enable L. hongkongensis to survive in different environmental niches. Genes encoding urease, bile salts efflux pump, adhesin, catalase, superoxide dismutase, and other putative virulence factors-such as hemolysins, RTX toxins, patatin-like proteins, phospholipase A1, and collagenases-are present. Proteomes of L. hongkongensis HLHK9 cultured at 37 degrees C (human body temperature and 20 degrees C (freshwater habitat temperature showed differential gene expression, including two homologous copies of argB, argB-20, and argB-37, which encode two isoenzymes of N-acetyl-L-glutamate kinase (NAGK-NAGK-20 and NAGK-37-in the arginine biosynthesis pathway. NAGK-20 showed higher expression at 20 degrees C, whereas NAGK-37 showed higher expression at 37 degrees C. NAGK-20 also had a lower optimal temperature for enzymatic activities and was inhibited by arginine probably as negative-feedback control. Similar duplicated copies of argB are also observed in bacteria from hot springs such as Thermus thermophilus, Deinococcus geothermalis, Deinococcus radiodurans, and Roseiflexus castenholzii, suggesting that similar mechanisms for temperature adaptation may be

  12. Regional temperature change potentials for short-lived climate forcers based on radiative forcing from multiple models

    Science.gov (United States)

    Aamaas, Borgar; Berntsen, Terje K.; Fuglestvedt, Jan S.; Shine, Keith P.; Collins, William J.

    2017-09-01

    We calculate the absolute regional temperature change potential (ARTP) of various short-lived climate forcers (SLCFs) based on detailed radiative forcing (RF) calculations from four different models. The temperature response has been estimated for four latitude bands (90-28° S, 28° S-28° N, 28-60° N, and 60-90° N). The regional pattern in climate response not only depends on the relationship between RF and surface temperature, but also on where and when emissions occurred and atmospheric transport, chemistry, interaction with clouds, and deposition. We present four emissions cases covering Europe, East Asia, the global shipping sector, and the entire globe. Our study is the first to estimate ARTP values for emissions during Northern Hemisphere summer (May-October) and winter season (November-April). The species studied are aerosols and aerosol precursors (black carbon, organic carbon, SO2, NH3), ozone precursors (NOx, CO, volatile organic compound), and methane (CH4). For the response to BC in the Arctic, we take into account the vertical structure of the RF in the atmosphere, and an enhanced climate efficacy for BC deposition on snow. Of all SLCFs, BC is the most sensitive to where and when the emissions occur, as well as giving the largest difference in response between the latitude bands. The temperature response in the Arctic per unit BC emission is almost four times larger and more than two times larger than the global average for Northern Hemisphere winter emissions for Europe and East Asia, respectively. The latitudinal breakdown likely gives a better estimate of the global temperature response as it accounts for varying efficacies with latitude. An annual pulse of non-methane SLCF emissions globally (representative of 2008) lead to a global cooling. In contrast, winter emissions in Europe and East Asia give a net warming in the Arctic due to significant warming from BC deposition on snow.

  13. Influence of composition on the biomethanation potential of restaurant waste at mesophilic temperatures.

    Science.gov (United States)

    Neves, L; Gonçalo, E; Oliveira, R; Alves, M M

    2008-01-01

    A synthetic waste was used to study the effect of waste composition on anaerobic degradation of restaurant waste. It was made by blending melted pork lard, white cabbage, chicken breast, and potato flakes, to simulate lipids, cellulose, protein, and carbohydrates, respectively. Four blends of the four constituents with an excess of each component were assayed and compared with a fifth blend containing an equal amount of chemical oxygen demand (COD) of each of the four components. The methane production and the time course of soluble COD and volatile fatty acids were assessed in batch assays. A high reduction of volatile solids (between 94% and 99.6%) was obtained in all the assays. The methane yield was between 0.40 m(3) CH(4)/kg VS(initial) (excess of carbohydrates) and 0.49 m(3) CH(4)/kg VS(initial) (excess of lipids). The degradation of the lipid-rich assays differed from the others. Fifty percent of the biochemical methane potential was obtained after 3-6 days for all of the assays, except for the one with excess of lipids which achieved 50% methanation only after 14.7 days of incubation. In the assay with excess of lipids, a considerable fraction of COD remained in the liquid phase, suggesting an inhibition of the methanogenic process that was likely due to the accumulation of long chain fatty acids. The hydrolysis rate constants, assuming first order kinetics, over the first 6 days were between 0.12d(-1) (excess of lipids) and 0.32 d(-1) (excess of carbohydrates). The results indicate that anaerobic digestion facilities with large variations in lipid input could have significant changes in process performance that merit further examination.

  14. Historical and potential changes of precipitation and temperature of Alberta subjected to climate change impact: 1900-2100

    Science.gov (United States)

    Jiang, Rengui; Gan, Thian Yew; Xie, Jiancang; Wang, Ni; Kuo, Chun-Chao

    2017-02-01

    We investigated changes to precipitation and temperature of Alberta for historical and future periods. First, the Mann-Kendall test and Sen's slope were used to test for historical trends and trend magnitudes from the climate data of Alberta, respectively. Second, the Special Report on Emissions Scenarios (SRES) (A1B, A2, and B1) of CMIP3 (Phase 3 of Coupled Model Intercomparison Project), projected by seven general circulation models (GCM) of the Intergovernmental Panel on Climate Change (IPCC) for three 30 years periods (2020s, 2050s, and 2080s), were used to evaluate the potential impact of climate change on precipitation and temperature of Alberta. Third, trends of projected precipitation and temperature were investigated, and differences between historical versus projected trends were estimated. Using the 50-km resolution dataset from CANGRD (Canadian Grid Climate Data), we found that Alberta had become warmer and somewhat drier for the past 112 years (1900-2011), especially in central and southern Alberta. For observed precipitation, upward trends mainly occurred in northern Alberta and at the leeward side of Canadian Rocky Mountains. However, only about 13 to 22 % of observed precipitation showed statistically significant increasing trends at 5 % significant level. Most observed temperature showed significant increasing trends, up to 0.05 °C/year in DJF (December, January, and February) in northern Alberta. GCMs' SRES projections indicated that seasonal precipitation of Alberta could change from -25 to 36 %, while the temperature would increase from 2020s to 2080s, with the largest increase (6.8 °C) in DJF. In all 21 GCM-SRES cases considered, precipitation in both DJF and MAM (March, April, and May) is projected to increase, while temperature is consistently projected to increase in all seasons, which generally agree with the trends of historical precipitation and temperature. The SRES A1B scenario of CCSM3 might project more realistic future climate for

  15. Phylogenetic and functional analysis of metagenome sequence from high-temperature archaeal habitats demonstrate linkages between metabolic potential and geochemistry

    Directory of Open Access Journals (Sweden)

    William P. Inskeep

    2013-05-01

    Full Text Available Geothermal habitats in Yellowstone National Park (YNP provide an unparalled opportunity to understand the environmental factors that control the distribution of archaea in thermal habitats. Here we describe, analyze and synthesize metagenomic and geochemical data collected from seven high-temperature sites that contain microbial communities dominated by archaea relative to bacteria. The specific objectives of the study were to use metagenome sequencing to determine the structure and functional capacity of thermophilic archaeal-dominated microbial communities across a pH range from 2.5 to 6.4 and to discuss specific examples where the metabolic potential correlated with measured environmental parameters and geochemical processes occurring in situ. Random shotgun metagenome sequence (~40-45 Mbase Sanger sequencing per site was obtained from environmental DNA extracted from high-temperature sediments and/or microbial mats and subjected to numerous phylogenetic and functional analyses. Analysis of individual sequences (e.g., MEGAN and G+C content and assemblies from each habitat type revealed the presence of dominant archaeal populations in all environments, 10 of whose genomes were largely reconstructed from the sequence data. Analysis of protein family occurrence, particularly of those involved in energy conservation, electron transport and autotrophic metabolism, revealed significant differences in metabolic strategies across sites consistent with differences in major geochemical attributes (e.g., sulfide, oxygen, pH. These observations provide an ecological basis for understanding the distribution of indigenous archaeal lineages across high temperature systems of YNP.

  16. Phylogenetic and Functional Analysis of Metagenome Sequence from High-Temperature Archaeal Habitats Demonstrate Linkages between Metabolic Potential and Geochemistry.

    Science.gov (United States)

    Inskeep, William P; Jay, Zackary J; Herrgard, Markus J; Kozubal, Mark A; Rusch, Douglas B; Tringe, Susannah G; Macur, Richard E; Jennings, Ryan deM; Boyd, Eric S; Spear, John R; Roberto, Francisco F

    2013-01-01

    Geothermal habitats in Yellowstone National Park (YNP) provide an unparalleled opportunity to understand the environmental factors that control the distribution of archaea in thermal habitats. Here we describe, analyze, and synthesize metagenomic and geochemical data collected from seven high-temperature sites that contain microbial communities dominated by archaea relative to bacteria. The specific objectives of the study were to use metagenome sequencing to determine the structure and functional capacity of thermophilic archaeal-dominated microbial communities across a pH range from 2.5 to 6.4 and to discuss specific examples where the metabolic potential correlated with measured environmental parameters and geochemical processes occurring in situ. Random shotgun metagenome sequence (∼40-45 Mb Sanger sequencing per site) was obtained from environmental DNA extracted from high-temperature sediments and/or microbial mats and subjected to numerous phylogenetic and functional analyses. Analysis of individual sequences (e.g., MEGAN and G + C content) and assemblies from each habitat type revealed the presence of dominant archaeal populations in all environments, 10 of whose genomes were largely reconstructed from the sequence data. Analysis of protein family occurrence, particularly of those involved in energy conservation, electron transport, and autotrophic metabolism, revealed significant differences in metabolic strategies across sites consistent with differences in major geochemical attributes (e.g., sulfide, oxygen, pH). These observations provide an ecological basis for understanding the distribution of indigenous archaeal lineages across high-temperature systems of YNP.

  17. Extensive phenotypic plasticity of a Red Sea coral over a strong latitudinal temperature gradient suggests limited acclimatization potential to warming

    KAUST Repository

    Sawall, Yvonne

    2015-03-10

    Global warming was reported to cause growth reductions in tropical shallow water corals in both, cooler and warmer, regions of the coral species range. This suggests regional adaptation with less heat-tolerant populations in cooler and more thermo-tolerant populations in warmer regions. Here, we investigated seasonal changes in the in situ metabolic performance of the widely distributed hermatypic coral Pocillopora verrucosa along 12° latitudes featuring a steep temperature gradient between the northern (28.5°N, 21-27°C) and southern (16.5°N, 28-33°C) reaches of the Red Sea. Surprisingly, we found little indication for regional adaptation, but strong indications for high phenotypic plasticity: Calcification rates in two seasons (winter, summer) were found to be highest at 28-29°C throughout all populations independent of their geographic location. Mucus release increased with temperature and nutrient supply, both being highest in the south. Genetic characterization of the coral host revealed low inter-regional variation and differences in the Symbiodinium clade composition only at the most northern and most southern region. This suggests variable acclimatization potential to ocean warming of coral populations across the Red Sea: high acclimatization potential in northern populations, but limited ability to cope with ocean warming in southern populations already existing at the upper thermal margin for corals.

  18. The effect of temperature and transmembrane potentials on the rates of electron transfer between membrane-bound biological redox components.

    Science.gov (United States)

    Kuznetsov, A M; Ulstrup, J

    1981-06-12

    We have investigated rate data for the temperature and free energy dependence of the primary electron-transfer processes in bacterial photosynthesis. Rather than representing the whole electronic-nuclear coupling by a frequently applied discrete single-mode model, we have incorporated a continuum of modes characterized by a certain distribution function. In this way, we can illuminate the role of both a broad distribution of low-frequency modes representing the medium and a narrow distribution representing local nuclear modes. Furthermore, it emerges from the calculations that both sets are important in the overall scheme of primary photosynthetic electron-transfer processes. By means of this model and quantum-mechanical rate theory, we can reproduce a number of important features of the primary photosynthetic processes concerning in particular the temperature (tunnelling or thermally activated nuclear motion) and free energy dependence ('normal', 'activation-less', or 'inverted' regions) of the rate constants and estimate such parameters as nuclear-reorganization energy electron-exchange integrals and electron-transfer distances. We have finally considered some of the important factors which determine the potential drop across the membrane and estimated the extent to which variations in the potential drop affect the rate constants of the electron-transfer processes.

  19. Extensive phenotypic plasticity of a Red Sea coral over a strong latitudinal temperature gradient suggests limited acclimatization potential to warming

    Science.gov (United States)

    Sawall, Yvonne; Al-Sofyani, Abdulmoshin; Hohn, Sönke; Banguera-Hinestroza, Eulalia; Voolstra, Christian R.; Wahl, Martin

    2015-03-01

    Global warming was reported to cause growth reductions in tropical shallow water corals in both, cooler and warmer, regions of the coral species range. This suggests regional adaptation with less heat-tolerant populations in cooler and more thermo-tolerant populations in warmer regions. Here, we investigated seasonal changes in the in situ metabolic performance of the widely distributed hermatypic coral Pocillopora verrucosa along 12° latitudes featuring a steep temperature gradient between the northern (28.5°N, 21-27°C) and southern (16.5°N, 28-33°C) reaches of the Red Sea. Surprisingly, we found little indication for regional adaptation, but strong indications for high phenotypic plasticity: Calcification rates in two seasons (winter, summer) were found to be highest at 28-29°C throughout all populations independent of their geographic location. Mucus release increased with temperature and nutrient supply, both being highest in the south. Genetic characterization of the coral host revealed low inter-regional variation and differences in the Symbiodinium clade composition only at the most northern and most southern region. This suggests variable acclimatization potential to ocean warming of coral populations across the Red Sea: high acclimatization potential in northern populations, but limited ability to cope with ocean warming in southern populations already existing at the upper thermal margin for corals.

  20. Lithium secondary batteries using an asymmetric sulfonium-based room temperature ionic liquid as a potential electrolyte

    Institute of Scientific and Technical Information of China (English)

    LUO ShiChun; ZHANG ZhengXi; YANG Li

    2008-01-01

    A new asymmetric sulfonium-based ionic liquid, 1-butyldimethylsulfonium bis(trifluoromethylsulfonyl) imide (S114TFSI), was developed as electrolyte material for lithium secondary battery. Its cathodic po-tential was a little more positive against the Li/Li+, so vinylene carbonate (VC) was added into the LiTFSI/S114TFSI ionic liquid electrolyte to ensure the formation of a solid electrolyte interface (SEI), which effectively prevented the decomposition of the electrolyte. The properties of the Li/LiMn2O4 cell containing S114TFSI-based electrolyte were studied and the cycle performances were compared to Electrochemical impedance spectroscopy (EIS) and X-ray diffraction (XRD) were conducted to analyze the mechanisms affecting the cell performances at different temperatures. The lithium secondary bat-tery system, using the above ionic liquid electrolyte material, shows good cycle performances and good safety at room temperature, and is worthwhile to further investigate so as to find out the potential application.

  1. A new method for temperature-field reconstruction during ultrasound-monitored cryosurgery using potential-field analogy.

    Science.gov (United States)

    Thaokar, Chandrajit; Rossi, Michael R; Rabin, Yoed

    2016-02-01

    The current study aims at developing computational tools in order to gain information about the thermal history in areas invisible to ultrasound imaging during cryosurgery. This invisibility results from the high absorption rate of the ultrasound energy by the frozen region, which leads to an apparent opacity in the cryotreated area and a shadow behind it. A proof-of-concept for freezing-front estimation is demonstrated in the current study, using the new potential-field analogy method (PFAM). This method is further integrated with a recently developed temperature-field reconstruction method (TFRM) to estimate the temperature distribution within the frozen region. This study uses prostate cryosurgery as a developmental model and trans-rectal ultrasound imaging as a choice of practice. Results of this study indicate that the proposed PFAM is a viable and computationally inexpensive solution to estimate the extent of freezing in the acoustic shadow region. Comparison of PFAM estimations and experimental data shows an average mismatch of less than 2 mm in freezing-front location, which is comparable to the uncertainty in ultrasound imaging. Comparison of the integrated PFAM + TFRM scheme with a full-scale finite-elements analysis (FEA) indicates an average mismatch of 0.9 mm for the freezing front location and 0.1 mm for the lethal temperature isotherm of -45 °C. Comparison of the integrated PFAM + TFRM scheme with experimental temperature measurements show a difference in the range of 2 °C and 6 °C for selected points of measurement. Results of this study demonstrate the integrated PFAM + TFRM scheme as a viable and computationally inexpensive means to gain information about the thermal history in the frozen region during ultrasound-monitored cryosurgery.

  2. The effect of sea surface temperature increase on the potential habitat ofOmmastrephes bartramii in the Northwest Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    XU Jie; CHEN Xinjun; CHEN Yong; DING Qi; TIAN Siquan

    2016-01-01

    In the Northwest Pacific Ocean, the squid jigging fisheries from China, Japan and other countries and regions have targeted the west winter-spring cohort of neon flying squid (Ommastrephes bartramii) from August to November since the 1970s. This squid is a short-lived ecological opportunist with a life-span of about one year, and its population is labile and recruitment variability is driven by the environment or climate change. This variability provides a challenge for ones to forecast the key habitats affected by climate change. The catch data of O. bartramii from Chinese squid jigging fishery and the satellite-derived sea surface temperature (SST) data are used in the Northwest Pacific Ocean from August to November of 1998 to 2004, the SST preferences ofO. bartramiicorresponding to high values of catch per fishing day (CPUE) are determined and monthly potential habitats are predicted using a histogram analysis of the SST data. The possible changes in the potential habitats of O. bartramii in the Northwest Pacific Ocean are estimated under four climate change scenarios based on the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change, i.e., 0.5, 1, 2 and 4°C increases in the SST because of the climate change. The results reveal an obvious poleward shift of the potential habitats ofO. bartramii in the Northwest Pacific Ocean.

  3. Phylogenetic and Functional Analysis of Metagenome Sequence from High-Temperature Archaeal Habitats Demonstrate Linkages between Metabolic Potential and Geochemistry

    DEFF Research Database (Denmark)

    Inskeep, William P; Jay, Zackary J; Herrgard, Markus

    2013-01-01

    from the sequence data. Analysis of protein family occurrence, particularly of those involved in energy conservation, electron transport, and autotrophic metabolism, revealed significant differences in metabolic strategies across sites consistent with differences in major geochemical attributes (e.......4 and to discuss specific examples where the metabolic potential correlated with measured environmental parameters and geochemical processes occurring in situ. Random shotgun metagenome sequence (∼40-45 Mb Sanger sequencing per site) was obtained from environmental DNA extracted from high-temperature sediments and....../or microbial mats and subjected to numerous phylogenetic and functional analyses. Analysis of individual sequences (e.g., MEGAN and G + C content) and assemblies from each habitat type revealed the presence of dominant archaeal populations in all environments, 10 of whose genomes were largely reconstructed...

  4. Accelerated Testing and Modeling of Potential-Induced Degradation as a Function of Temperature and Relative Humidity

    Energy Technology Data Exchange (ETDEWEB)

    Hacke, Peter; Spataru, Sergiu; Terwilliger, Kent; Perrin, Greg; Glick, Stephen; Kurtz, Sarah; Wohlgemuth, John

    2015-06-14

    An acceleration model based on the Peck equation was applied to power performance of crystalline silicon cell modules as a function of time and of temperature and humidity, the two main environmental stress factors that promote potential-induced degradation. This model was derived from module power degradation data obtained semi-continuously and statistically by in-situ dark current-voltage measurements in an environmental chamber. The modeling enables prediction of degradation rates and times as functions of temperature and humidity. Power degradation could be modeled linearly as a function of time to the second power; additionally, we found that coulombs transferred from the active cell circuit to ground during the stress test is approximately linear with time. Therefore, the power loss could be linearized as a function of coulombs squared. With this result, we observed that when the module face was completely grounded with a condensed phase conductor, leakage current exceeded the anticipated corresponding degradation rate relative to the other tests performed in damp heat.

  5. Effects of calcination temperature and acid-base properties on mixed potential ammonia sensors modified by metal oxides.

    Science.gov (United States)

    Satsuma, Atsushi; Katagiri, Makoto; Kakimoto, Shiro; Sugaya, Satoshi; Shimizu, Kenichi

    2011-01-01

    Mixed potential sensors were fabriated using yttria-stabilized zirconia (YSZ) as a solid electrolyte and a mixture of Au and various metal oxides as a sensing electrode. The effects of calcination temperature ranging from 600 to 1,000 °C and acid-base properties of the metal oxides on the sensing properties were examined. The selective sensing of ammonia was achieved by modification of the sensing electrode using MoO(3), Bi(2)O(3) and V(2)O(5), while the use of WO(3,) Nb(2)O(5) and MgO was not effective. The melting points of the former group were below 820 °C, while those of the latter group were higher than 1,000 °C. Among the former group, the selective sensing of ammonia was strongly dependent on the calcination temperature, which was optimum around melting point of the corresponding metal oxides. The good spreading of the metal oxides on the electrode is suggested to be one of the important factors. In the former group, the relative response of ammonia to propene was in the order of MoO(3) > Bi(2)O(3) > V(2)O(5), which agreed well with the acidity of the metal oxides. The importance of the acidic properties of metal oxides for ammonia sensing was clarified.

  6. Effects of Calcination Temperature and Acid-Base Properties on Mixed Potential Ammonia Sensors Modified by Metal Oxides

    Directory of Open Access Journals (Sweden)

    Kenichi Shimizu

    2011-02-01

    Full Text Available Mixed potential sensors were fabriated using yttria-stabilized zirconia (YSZ as a solid electrolyte and a mixture of Au and various metal oxides as a sensing electrode. The effects of calcination temperature ranging from 600 to 1,000 °C and acid-base properties of the metal oxides on the sensing properties were examined. The selective sensing of ammonia was achieved by modification of the sensing electrode using MoO3, Bi2O3 and V2O5, while the use of WO3, Nb2O5 and MgO was not effective. The melting points of the former group were below 820 °C, while those of the latter group were higher than 1,000 °C. Among the former group, the selective sensing of ammonia was strongly dependent on the calcination temperature, which was optimum around melting point of the corresponding metal oxides. The good spreading of the metal oxides on the electrode is suggested to be one of the important factors. In the former group, the relative response of ammonia to propene was in the order of MoO3 > Bi2O3 > V2O5, which agreed well with the acidity of the metal oxides. The importance of the acidic properties of metal oxides for ammonia sensing was clarified.

  7. Effects of Calcination Temperature and Acid-Base Properties on Mixed Potential Ammonia Sensors Modified by Metal Oxides

    Science.gov (United States)

    Satsuma, Atsushi; Katagiri, Makoto; Kakimoto, Shiro; Sugaya, Satoshi; Shimizu, Kenichi

    2011-01-01

    Mixed potential sensors were fabriated using yttria-stabilized zirconia (YSZ) as a solid electrolyte and a mixture of Au and various metal oxides as a sensing electrode. The effects of calcination temperature ranging from 600 to 1,000 °C and acid-base properties of the metal oxides on the sensing properties were examined. The selective sensing of ammonia was achieved by modification of the sensing electrode using MoO3, Bi2O3 and V2O5, while the use of WO3, Nb2O5 and MgO was not effective. The melting points of the former group were below 820 °C, while those of the latter group were higher than 1,000 °C. Among the former group, the selective sensing of ammonia was strongly dependent on the calcination temperature, which was optimum around melting point of the corresponding metal oxides. The good spreading of the metal oxides on the electrode is suggested to be one of the important factors. In the former group, the relative response of ammonia to propene was in the order of MoO3 > Bi2O3 > V2O5, which agreed well with the acidity of the metal oxides. The importance of the acidic properties of metal oxides for ammonia sensing was clarified. PMID:22319402

  8. Light might regulate divergently depside and depsidone accumulation in the lichen Parmotrema hypotropum by affecting thallus temperature and water potential.

    Science.gov (United States)

    Armaleo, Daniele; Zhang, Yi; Cheung, Sonia

    2008-01-01

    Depsides and depsidones are the most common secondary products uniquely produced in lichens by the fungal symbiont, and they accumulate on the outer surface of its hyphae. Their biological roles are subject to debate. Quantitatively the compounds typical of a given lichen can vary dramatically from thallus to thallus. Several studies have addressed whether this variability is correlated with the light reaching different thalli, but the conclusions are contradictory. We addressed the question with the lichen Parmotrema hypotropum growing on unshaded, vertical tree trunks, a controlled natural environment where the light absorbed by each thallus over its lifetime is the only major position-dependent variable. The exact north-east-south-west orientation of each thallus was used to calculate its yearly light exposure based on astronomical and meteorological considerations. The calculated irradiation around the trunk, distributed over a continuous 40-fold intensity range, then was compared with the amount of compound per unit thallus weight, determined by quantitative thin layer chromatography. P. hypotropum accumulates the depside atranorin in the cortex and the depsidone norstictic acid in the medulla and around the algae. A direct correlation was observed between the yearly amount of light reaching the lichen and the amount of atranorin. In contrast, the amount of norstictic acid decreased with increasing light. Although we did not measure thallus temperature and water potential, a unifying interpretation of these and other published data is that depside/depsidone accumulation in lichens is mediated by localized changes in temperature and water potential produced by light absorption within each thallus. This suggests water relations-based functions for depsides and depsidones.

  9. Modelling the impact of temperature-induced life history plasticity and mate limitation on the epidemic potential of a marine ectoparasite.

    Directory of Open Access Journals (Sweden)

    Maya L Groner

    Full Text Available Temperature is hypothesized to contribute to increased pathogenicity and virulence of many marine diseases. The sea louse (Lepeophtheirus salmonis is an ectoparasite of salmonids that exhibits strong life-history plasticity in response to temperature; however, the effect of temperature on the epidemiology of this parasite has not been rigorously examined. We used matrix population modelling to examine the influence of temperature on demographic parameters of sea lice parasitizing farmed salmon. Demographically-stochastic population projection matrices were created using parameters from the existing literature on vital rates of sea lice at different fixed temperatures and yearly temperature profiles. In addition, we quantified the effectiveness of a single stage-specific control applied at different times during a year with seasonal temperature changes. We found that the epidemic potential of sea lice increased with temperature due to a decrease in generation time and an increase in the net reproductive rate. In addition, mate limitation constrained population growth more at low temperatures than at high temperatures. Our model predicts that control measures targeting preadults and chalimus are most effective regardless of the temperature. The predictions from this model suggest that temperature can dramatically change vital rates of sea lice and can increase population growth. The results of this study suggest that sea surface temperatures should be considered when choosing salmon farm sites and designing management plans to control sea louse infestations. More broadly, this study demonstrates the utility of matrix population modelling for epidemiological studies.

  10. Very-low-frequency resistivity, self-potential and ground temperature surveys on Taal volcano (Philippines): Implications for future activity

    Science.gov (United States)

    Zlotnicki, J.; Vargemezis, G.; Johnston, M. J. S.; Sasai, Y.; Reniva, P.; Alanis, P.

    2017-06-01

    Taal volcano is one of the most dangerous volcanoes in the Philippines. Thirty-three eruptions have occurred through historical time with several exhibiting cataclysmic phases. Most recent eruptions are confined to Volcano Island located within the prehistoric Taal collapse caldera that is now filled by Taal Lake. The last eruptive activity from 1965 to 1977 took place from Mt. Tabaro, about 2 km to the southwest of the Main Crater center. Since this time, episodes of seismic activity, ground deformation, gas release, surface fissuring, fumarole activity and temperature changes are recorded periodically around the main crater, but no major eruption has occurred. This period of quiescence is the third longest period without eruptive activity since 1572. In March 2010, a campaign based on Very-Low-Frequency (VLF) resistivity surveys together with repeated surveys of self-potential, ground temperature and fissure activity was intensified and the results compared to a large-scale Electrical Resistivity Tomography experiment. This work fortunately occurred before, within and after a new seismovolcanic crisis from late April 2010 to March 2011. The joint analysis of these new data, together with results from previous magnetotelluric soundings, allows a better description of the electrical resistivity and crustal structure beneath the Main Crater down to a depth of several kilometers. No indication of growth of the two geothermal areas located on both sides of the northern crater rim was apparent from 2005 to March 2010. These areas appear controlled by active fissures, opened during the 1992 and 1994 crises, that dip downward towards the core of the hydrothermal system located at about 2.5 km depth beneath the crater. Older mineralized fissures at lower elevations to the North of the geothermal areas also dip downward under the crater. Repeated self-potential and ground temperature surveys completed between 2005 and 2015 show new geothermal and hydrothermal activity in

  11. A portable microfluidic device for the rapid diagnosis of cancer metastatic potential which is programmable for temperature and CO2.

    Science.gov (United States)

    Yu, I F; Yu, Y H; Chen, L Y; Fan, S K; Chou, H Y E; Yang, J T

    2014-09-21

    If metastasis of lung cancer can be found and treated early, a victim might have an improved chance to prevail over it, but routine examinations such as chest radiography, computed tomography and biopsy cannot characterize the metastatic potential of lung cancer cells; critical diagnoses to define optimal therapeutic strategies are thus lost. We designed a portable microfluidic device for the rapid diagnosis of cancer metastatic potential. Featuring a micro system to control temperature and a bicarbonate buffered environment, our device discriminates a rate of surface detachment as an index of the migratory ability of cells cultured on pH-responsive chitosan. We labeled metastatic subpopulations of lung cancer cell lines, and verified that our device is capable of separating cells according to their metastatic ability. As only few cells are needed, a patient's specimen from biopsies, e.g. from fine-needle aspiration, can be processed on site to offer immediate information to physicians. We expect that our design will provide valuable information in pre-operative evaluations to assist the definition of therapeutic plans for lung cancer, as well as for metastatic tumors of other types.

  12. Simulating potential structural and operational changes for Detroit Dam on the North Santiam River, Oregon, for downstream temperature management

    Science.gov (United States)

    Buccola, Norman L.; Rounds, Stewart A.; Sullivan, Annett B.; Risley, John C.

    2012-01-01

    achievement of downstream temperature goals requires that releases of warm water near the surface of the lake and cold water below the thermocline are both possible with the available dam outlets during spring, summer, and autumn. This constraint can be met to some extent with existing outlets, but only if access to the spillway is extended into autumn by keeping the lake level higher than called for by the current rule curve (the typical target water-surface elevation throughout the year). If new outlets are considered, a variable-elevation outlet such as a sliding gate structure, or a floating outlet in combination with a fixed-elevation outlet at sufficient depth to access cold water, is likely to work well in terms of accessing a range of water temperatures and achieving downstream temperature targets. Furthermore, model results indicate that it is important to release warm water from near the lake surface during midsummer. If not released downstream, the warm water will build up at the top of the lake as a result of solar energy inputs and the thermocline will deepen, potentially causing warm water to reach the depth of deeper fixed-elevation outlets in autumn, particularly when the lake level is drawn down to make room for flood storage. Delaying the drawdown in autumn can help to keep the thermocline above such outlets and preserve access to cold water. Although it is important to generate hydropower at Detroit Dam, minimum power-production requirements limit the ability of dam operators to meet downstream temperature targets with existing outlet structures. The location of the power penstocks below the thermocline in spring and most of summer causes the release of more cool water during summer than is optimal. Reducing the power-production constraint allows the temperature target to be met more frequently, but at the cost of less power generation. Finally, running the Detroit Dam, Big Cliff Dam, and North Santiam and Santiam River models in series allows dam operators

  13. SU-E-T-353: Effects of Time and Temperature On a Potential Reusable 3D Dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Juang, T; Miles, D; Crockett, E [Medical Physics Graduate Program, Duke University Medical Center, Durham, NC (United States); Adamovics, J [Rider University, Skillman, NJ (United States); Oldham, M [Duke University Medical Center, Durham, NC (United States)

    2015-06-15

    Purpose: Preliminary studies of a novel, optically-clearing PRESAGE 3D dosimeter formulation (Presage-RU) demonstrated potential reusability. This study investigates the effects of time and temperature on the accuracy and reusability of Presage-RU, and reports on progress toward developing a reusable 3D dosimeter. Methods: Presage-RU was cast as small volume samples (1×1×4.5cm). The effect of dose response sensitivity with reirradiation and time was evaluated by irradiating samples from 0–10Gy, measuring change in optical density (ΔOD), clearing at room temperature (RT) (5–7 days to fully clear), and then repeating for a total of 5 irradiations. Effects of heating on clearing rate were investigated by irradiating samples to 8Gy, then tracking measurements with samples held at RT, 35°C, and 45°C. Two cylindrical dosimeters (11cm diameter, 9.5cm length) were evaluated for dosimetric accuracy when stored at RT and −3°C prior to irradiation. Plans delivered were 2 overlapping AP fields (RT) and VMAT (-3°C). Results: Heating the dosimeters reduced the clearing half-life from 16.3h at RT to 5.8h (35°C) and 5.1h (45°C), but also increased background ΔOD by 1.7x (35°C) and 2.3x (45°C). Reductions in dose response were more closely linked to age than reirradiation, and storage at RT showed pronounced desensitization from dosimeter edges. These results suggest desensitization from oxygen diffusion. It should be noted that atmospheric diffusion into the dosimeter is not seen in standard, single-use PRESAGE, and is likely caused by differences in the Presage-RU polyurethane matrix. The dosimeter kept in cold storage, however, showed no evidence of desensitization and exhibited accuracy on par with standard PRESAGE with a 3%/3mm 3D gamma passing rate of 98.1%. Conclusions: Presage-RU is sensitive to storage temperatures and time, both of which affect oxygen diffusion and subsequent desensitization. Development shows promising progress with further formulation

  14. Field Sandbur (Cenchrus pauciflorus) Seeds in the Same Bur Respond Differently to Temperature and Water Potential in Relation to Germination in a Semi-Arid Environment, China.

    Science.gov (United States)

    Zhang, Zhixin; Tian, Xun; Bai, Yuguang; Liu, Huifang; Niu, Xueli; Wang, Zhiwei; Wang, Qian

    2016-01-01

    The success of a biological invasion relies on the environment and is closely linked to factors such as water and temperature. Invasive plant species display different seed characteristics, including shape. Field sandbur (Cenchrus pauciflorus) is a globally widespread invasive species capable of adapting to broad environmental conditions. However, its germination response to water and temperature still remains unclear. C. pauciflorus contains two seeds in the same bur that differ in size: big seeds (M) and small seeds (P). Separate greenhouse experiments were conducted under different temperature regimes (0/10°C, 5/15°C, 10/20°C, 15/25°C, 18/28°C, 20/30°C and 25/35°C) and water potentials (-1.50Mpa, -1.00Mpa, -0.75Mpa, -0.50Mpa, -0.25Mpa and 0Mpa) for M and P seeds. The results support the hypothesis that germination of C. pauciflorus is significantly influenced by seed type, temperature and water potential. M and P seeds responded differently to varied alternative temperatures and water potentials. However, M and P seeds were more sensitive to water potential than to temperature. Optimal conditions for M and P seed germination were measured at 25/35°C (night temperature/day temperature) and 20/30°C, respectively. In contrast, the highest germination rate was observed for the 0Mpa of the water potential treatment. Additionally, base temperature (Tbase) and base water potential (Wbase) were lower for M (7.7°C, -1.11Mpa at 10/20°C, and -1.07Mpa at 20/30°C) than for P (9.4°C, -0.92Mpa at 10/20°C, and -0.52Mpa at 20/30°C). These different germination strategies of M and P seeds with respect to temperature and water potential increased overall plant propagation. These results indicate that tropical and subtropical regions water potentials beyond -0.50Mpa (10/20°C) or -1.00Mpa (20/30°C) face a potential risk of C. pauciflorus invasion.

  15. Magnetically insulated baffled probe for real-time monitoring of equilibrium and fluctuating values of space potentials, electron and ion temperatures, and densities.

    Science.gov (United States)

    Demidov, V I; Koepke, M E; Raitses, Y

    2010-10-01

    By restricting the electron-collection area of a cold Langmuir probe compared to the ion-collection area, the probe floating potential can become equal to the space potential, and thus conveniently monitored, rather than to a value shifted from the space potential by an electron-temperature-dependent offset, i.e., the case with an equal-collection-area probe. This design goal is achieved by combining an ambient magnetic field in the plasma with baffles, or shields, on the probe, resulting in species-selective magnetic insulation of the probe collection area. This permits the elimination of electron current to the probe by further adjustment of magnetic insulation which results in an ion-temperature-dependent offset when the probe is electrically floating. Subtracting the floating potential of two magnetically insulated baffled probes, each with a different degree of magnetic insulation, enables the electron or ion temperature to be measured in real time.

  16. Responses of action potential and K+ currents to temperature acclimation in fish hearts: phylogeny or thermal preferences?

    Science.gov (United States)

    Haverinen, Jaakko; Vornanen, Matti

    2009-01-01

    Electrical activity of the heart is assumed to be one of the key factors that set thermal tolerance limits for ectothermic vertebrates. Therefore, we hypothesized that in thermal acclimation--the duration of cardiac action potential and the repolarizing K+ currents that regulate action potential duration (APD)--the rapid component of the delayed rectifier K+ current (I(Kr)) and the inward rectifier K+ current (I(K1)) are more plastic in eurythermal than in stenothermal fish species. The hypothesis was tested in six freshwater teleosts representing four different fish orders (Cadiformes, Cypriniformes, Perciformes, Salmoniformes) acclimated at +4 degrees C (cold acclimation) or +18 degrees C (warm acclimation). In cold acclimation, a compensatory shortening of APD occurred in all species regardless of thermal tolerances, life styles, or phylogenies of the fish, suggesting that this response is a common characteristic of the teleost heart. The strength of the response did not, however, obey simple eurythermy-stenothermy gradation but differed among the phylogenetic groups. Salmoniformes fish showed the greatest acclimation capacity of cardiac electrical activity, whereas the weakest response appeared in the perch (Perciformes) heart. The underlying ionic mechanisms were also partly phylogeny dependent. Modification of the I(Kr) current was al- most ubiquitously involved in acclimation response of fish cardiac myocytes to temperature, while the ability to change the I(K1) current under chronic thermal stress was absent or showed inverse compensation in Salmoniformes species. Thus, in Salmoniformes fish, the thermal plasticity of APD is strongly based on I(Kr), while other fish groups rely on both I(Kr) and I(K1).

  17. Regulation of Mnemiopsis leidyi dynamics by potential changes in temperature and zooplankton conditions in the Black Sea.

    Science.gov (United States)

    Salihoglu, B.; Fach, B.; Oguz, T.

    2009-04-01

    Providing a comprehensive understanding of the effects that cause formations of ctenophore blooms in the Black Sea is the main objective of this study. In order to analyse ctenophore dynamics in the Black Sea a zero-dimensional population based model of the ctenophore Mnemiopsis leidyi is developed. The stage resolving ctenophore model combines the modified form of stage resolving approach of Fennel, 2001 with the growth dynamics model of Kremer, 1976; Kremer and Reeve, 1989 under 4 stages of model-ctenophore. These stages include the different growth characteristics of egg, juvenile, transitional and adult stages. The dietary patterns of the different stages follows the observations obtained from the literature. The model is able to represent consistent development patterns, while reflecting the physiological complexity of a population of Mnemiopsis leidyi. Model results suggest that different nutritional requirement of each stage may serve as the bottlenecks for population growth and only when growth conditions are favorable for both larval and lobate stages, the high overall population growth rates may occur. Model is also used to analyse the influence of climatic changes on Mnemiopsis leidyi reproduction and outburst. This study presents and discussed how potential changes in temperature and zooplankton conditions in the Black Sea may regulate Mnemiopsis leidyi dynamics.

  18. Unlocking the potential of supported liquid phase catalysts with supercritical fluids: low temperature continuous flow catalysis with integrated product separation.

    Science.gov (United States)

    Franciò, Giancarlo; Hintermair, Ulrich; Leitner, Walter

    2015-12-28

    Solution-phase catalysis using molecular transition metal complexes is an extremely powerful tool for chemical synthesis and a key technology for sustainable manufacturing. However, as the reaction complexity and thermal sensitivity of the catalytic system increase, engineering challenges associated with product separation and catalyst recovery can override the value of the product. This persistent downstream issue often renders industrial exploitation of homogeneous catalysis uneconomical despite impressive batch performance of the catalyst. In this regard, continuous-flow systems that allow steady-state homogeneous turnover in a stationary liquid phase while at the same time effecting integrated product separation at mild process temperatures represent a particularly attractive scenario. While continuous-flow processing is a standard procedure for large volume manufacturing, capitalizing on its potential in the realm of the molecular complexity of organic synthesis is still an emerging area that requires innovative solutions. Here we highlight some recent developments which have succeeded in realizing such systems by the combination of near- and supercritical fluids with homogeneous catalysts in supported liquid phases. The cases discussed exemplify how all three levels of continuous-flow homogeneous catalysis (catalyst system, separation strategy, process scheme) must be matched to locate viable process conditions.

  19. The potential effect of differential ambient and deployment chamber temperatures on PRC derived sampling rates with polyurethane foam (PUF) passive air samplers

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Karen, E-mail: k.kennedy@uq.edu.a [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia); Hawker, Darryl W. [Griffith University, School of Environment, Nathan QLD 4111 (Australia); Bartkow, Michael E. [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia); Carter, Steve [Queensland Health Forensic and Scientific Services, Coopers Plains QLD 4108 (Australia); Ishikawa, Yukari; Mueller, Jochen F. [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia)

    2010-01-15

    Performance reference compound (PRC) derived sampling rates were determined for polyurethane foam (PUF) passive air samplers in both sub-tropical and temperate locations across Australia. These estimates were on average a factor of 2.7 times higher in summer than winter. The known effects of wind speed and temperature on mass transfer coefficients could not account for this observation. Sampling rates are often derived using ambient temperatures, not the actual temperatures within deployment chambers. If deployment chamber temperatures are in fact higher than ambient temperatures, estimated sampler-air partition coefficients would be greater than actual partition coefficients resulting in an overestimation of PRC derived sampling rates. Sampling rates determined under measured ambient temperatures and estimated deployment chamber temperatures in summer ranged from 7.1 to 10 m{sup 3} day{sup -1} and 2.2-6.8 m{sup 3} day{sup -1} respectively. These results suggest that potential differences between ambient and deployment chamber temperatures should be considered when deriving PRC-based sampling rates. - Internal deployment chamber temperatures rather than ambient temperatures may be required to accurately estimate PRC-based sampling rates.

  20. Communication: Rigorous quantum dynamics of O + O2 exchange reactions on an ab initio potential energy surface substantiate the negative temperature dependence of rate coefficients.

    Science.gov (United States)

    Li, Yaqin; Sun, Zhigang; Jiang, Bin; Xie, Daiqian; Dawes, Richard; Guo, Hua

    2014-08-28

    The kinetics and dynamics of several O + O2 isotope exchange reactions have been investigated on a recently determined accurate global O3 potential energy surface using a time-dependent wave packet method. The agreement between calculated and measured rate coefficients is significantly improved over previous work. More importantly, the experimentally observed negative temperature dependence of the rate coefficients is for the first time rigorously reproduced theoretically. This negative temperature dependence can be attributed to the absence in the new potential energy surface of a submerged "reef" structure, which was present in all previous potential energy surfaces. In addition, contributions of rotational excited states of the diatomic reactant further accentuate the negative temperature dependence.

  1. The temperature response of CO2 assimilation, photochemical activities and Rubisco activation in Camelina sativa, a potential bioenergy crop with limited capacity for acclimation to heat stress.

    Science.gov (United States)

    Carmo-Silva, A Elizabete; Salvucci, Michael E

    2012-11-01

    The temperature optimum of photosynthesis coincides with the average daytime temperature in a species' native environment. Moderate heat stress occurs when temperatures exceed the optimum, inhibiting photosynthesis and decreasing productivity. In the present study, the temperature response of photosynthesis and the potential for heat acclimation was evaluated for Camelina sativa, a bioenergy crop. The temperature optimum of net CO(2) assimilation rate (A) under atmospheric conditions was 30-32 °C and was only slightly higher under non-photorespiratory conditions. The activation state of Rubisco was closely correlated with A at supra-optimal temperatures, exhibiting a parallel decrease with increasing leaf temperature. At both control and elevated temperatures, the modeled response of A to intercellular CO(2) concentration was consistent with Rubisco limiting A at ambient CO(2). Rubisco activation and photochemical activities were affected by moderate heat stress at lower temperatures in camelina than in the warm-adapted species cotton and tobacco. Growth under conditions that imposed a daily interval of moderate heat stress caused a 63 % reduction in camelina seed yield. Levels of cpn60 protein were elevated under the higher growth temperature, but acclimation of photosynthesis was minimal. Inactivation of Rubisco in camelina at temperatures above 35 °C was consistent with the temperature response of Rubisco activase activity and indicated that Rubisco activase was a prime target of inhibition by moderate heat stress in camelina. That photosynthesis exhibited no acclimation to moderate heat stress will likely impact the development of camelina and other cool season Brassicaceae as sources of bioenergy in a warmer world.

  2. The effect of the substrate temperature and the acceleration potential drop on the structural and physical properties of SiC thin films deposed by TVA method

    Science.gov (United States)

    Ciupina, Victor; Lungu, Cristian P.; Vladoiu, Rodica; Prodan, Gabriel C.; Antohe, Stefan; Porosnicu, Corneliu; Stanescu, Iuliana; Jepu, Ionut; Iftimie, Sorina; Prodan, Madalina; Mandes, Aurelia; Dinca, Virginia; Vasile, Eugeniu; Zarovski, Valeriu; Nicolescu, Virginia

    2014-08-01

    Crystalline Si-C thin films were prepared at substrate temperature between 200°C and 1000°C using Thermionic Vacuum Arc (TVA) method. To increase the acceleration potential drop a negative bias voltage up to -1000V was applied on the substrate. The 200nm thickness carbon thin films was deposed on glass and Si substrate and then 200-500 nm thickness Si-C layer on carbon thin films was deposed. Transmission Electron Microscopy (TEM), High Resolution Transmission Electron Microscopy (HRTEM), X-Ray Photoelectron Spectroscopy (XPS), and electrical conductivity measurement technique characterized the structure and physical characteristics of as-prepared SiC coating. At a constant acceleration potential drop, the electrical conductivity of the Si-C films deposed on C, increase with increasing of substrate temperature. On the other part, significant increases in the acceleration potential drop at constant substrate temperature lead to a variation of the crystallinity and electrical conductivity of the SiC coatings XPS analysis was performed using a Quantera SXM equipment, with monochromatic AlKα radiation at 1486.6eV. Electrical conductivity of the Si-C coating on carbon at different temperatures was measured comparing the potential drop on the sample with the potential drop on a series standard resistance in constant mode.

  3. Short-term Effects of Air Temperature on Blood Markers of Coagulation and Inflammation in Potentially Susceptible Individuals

    Science.gov (United States)

    Objectives: Changes in air temperature are associated with an increase in cardiovascular events, but the role of pro-coagulant and pro-inflammatory blood markers is still poorly understood. We investigated the association between air temperature and fibrinogen, plasminogen act...

  4. The Morphology, Dynamics and Potential Hotspots of Land Surface Temperature at a Local Scale in Urban Areas

    Directory of Open Access Journals (Sweden)

    Jiong Wang

    2015-12-01

    Full Text Available Current characterization of the Urban Heat Island (UHI remains insufficient to support the effective mitigation and adaptation of increasing temperatures in urban areas. Planning and design strategies are restricted to the investigation of temperature anomalies at a city scale. By focusing on Land Surface Temperature of Wuhan, China, this research examines the temperature variations locally where mitigation and adaptation would be more feasible. It shows how local temperature anomalies can be identified morphologically. Technically, the MODerate-resolution Imaging Spectroradiometer satellite image products are used. They are first considered as noisy observations of the latent temperature patterns. The continuous latent patterns of the temperature are then recovered from these discrete observations by using the non-parametric Multi-Task Gaussian Process Modeling. The Multi-Scale Shape Index is then applied in the area of focus to extract the local morphological features. A triplet of shape, curvedness and temperature is formed as the criteria to extract local heat islands. The behavior of the local heat islands can thus be quantified morphologically. The places with critical deformations are identified as hotpots. The hotspots with certain yearly behavior are further associated with land surface composition to determine effective mitigation and adaptation strategies. This research can assist in the temperature and planning field on two levels: (1 the local land surface temperature patterns are characterized by decomposing the variations into fundamental deformation modes to allow a process-based understanding of the dynamics; and (2 the characterization at local scale conforms to planning and design conventions where mitigation and adaptation strategies are supposed to be more practical. The weaknesses and limitations of the study are addressed in the closing section.

  5. Extreme maximum temperature events and their relationships with large-scale modes: potential hazard on the Iberian Peninsula

    Science.gov (United States)

    Merino, Andrés; Martín, M. L.; Fernández-González, S.; Sánchez, J. L.; Valero, F.

    2017-07-01

    The aim of this paper is to analyze spatiotemporal distribution of maximum temperatures in the Iberian Peninsula (IP) by using various extreme maximum temperature indices. Thresholds for determining temperature extreme event (TEE) severity are defined using 99th percentiles of daily temperature time series for the period 1948 to 2009. The synoptic-scale fields of such events were analyzed in order to better understand the related atmospheric processes. The results indicate that the regions with a higher risk of maximum temperatures are located in the river valleys of southwest and northeast of the IP, while the Cantabrian coast and mountain ranges are characterized by lower risk. The TEEs were classified, by means of several synoptic fields (sea level pressure, temperature, and geopotential height at 850 and 500 hPa), in four clusters that largely explain their spatiotemporal distribution on the IP. The results of this study show that TEEs mainly occur associated with a ridge elongated from Subtropical areas. The relationships of TEEs with teleconnection patterns, such as the North Atlantic Oscillation (NAO), Western Mediterranean Oscillation (WeMO), and Mediterranean Oscillation (MO), showed that the interannual variability of extreme maximum temperatures is largely controlled by the dominant phase of WeMO in all seasons except wintertime where NAO is prevailing. Results related to MO pattern show less relevance in the maximum temperatures variability. The correct identification of synoptic patterns linked with the most extreme temperature event associated with each cluster will assist the prediction of events that can pose a natural hazard, thereby providing useful information for decision making and warning systems.

  6. Large scale features associated with strong frontogenesis in equivalent potential temperature in the South American subtropics east of the Andes

    Directory of Open Access Journals (Sweden)

    J. M. Arraut

    2009-10-01

    Full Text Available South American subtropics east of the Andes exhibit a region of intense climatological frontogenesis in equivalent potential temperature (EPT in the December to March season, mostly produced by deformation of the wind field. The goal of this paper is to investigate the large scale features associated with intense and weak frontogenesis by deformation (FGD in EPT in the region where it attains its climatological maximum. This can be approximately delimited by 32–42° S and 66–69° W, which is small enough as to contain only one synoptic perturbation at a time. The spatial average of the positive values of frontogenesis at 850 hPa over the whole region (DFG+ is used to represent the strength of the perturbation. ECMWF ERA-40 reanalysis data set is used to calculate DFG+ at six hour intervals for 21 seasons (1981–2002. Compositing analysis is carried out for strong (above the 0.75 quantile and weak (below the 0.25 quantile events. For strong events the geopotential field at 850 hPa exhibits the North Argentinean Low (NAL, a transient trough and the Low Pressure Tongue East of the Andes (LPT. Upon comparison with the composite field of FGD it can be observed that FGD exhibits a strong maximum over the Argentinean Col (AC which separates the NAL and the trough. These features are absent in the weak frontogenesis composite, which exhibits a stronger South Pacific Subtropical High close to the continent. At 250 hPa the strong FGD composite exhibits a trough over the Andes with a wind speed maximum to its east. Both of these features are associated with the deepening of the NAL in the literature. These are not present in the weak FGD composites. Strong events show an intense quasi meridional corridor of water vapor transport from the Amazon to the subtropics that encounters westerly flow in the neighborhood of the AC. This is absent in weak events. A preliminary analysis of precipitation is carried out using the GPCP daily data set. An intense

  7. Temperature-Responsive Gelation of Type I Collagen Solutions Involving Fibril Formation and Genipin Crosslinking as a Potential Injectable Hydrogel

    OpenAIRE

    Shunji Yunoki; Yoshimi Ohyabu; Hirosuke Hatayama

    2013-01-01

    We investigated the temperature-responsive gelation of collagen/genipin solutions using pepsin-solubilized collagen (PSC) and acid-solubilized collagen (ASC) as substrates. Gelation occurred in the PSC/genipin solutions at genipin concentrations 0–2 mM under moderate change in temperature from 25 to 37°C. The PSC/genipin solutions exhibited fluidity at room temperature for at least 30 min, whereas the ASC/genipin solutions rapidly reached gel points. In specific cases PSC would be preferred o...

  8. The nonlinear optical rectification and second harmonic generation in asymmetrical Gaussian potential quantum well: Effects of hydrostatic pressure, temperature and magnetic field

    Science.gov (United States)

    Liu, Xin; Zou, LiLi; Liu, Chenglin; Zhang, Zhi-Hai; Yuan, Jian-Hui

    2016-03-01

    In the present work, the effects of hydrostatic pressure, temperature, and magnetic field on the nonlinear optical rectification (OR) and second-harmonic generation (SHG) in asymmetrical Gaussian potential quantum well (QW) have been investigated theoretically. Here, the expressions for the optical properties are calculated by the compact-density-matrix approach and iterative method. Simultaneously, the energy eigenvalues and their corresponding eigenfunctions have been obtained by using the finite difference method. The energy eigenvalues and the shape of the confined potential are modulated by the hydrostatic pressure, temperature, and magnetic field. So the results of a number of numerical experiments indicate that the nonlinear OR and SHG strongly depends on the hydrostatic pressure, temperature, and magnetic field. This gives a new degree of freedom in various device applications based on the intersubband transitions of electrons.

  9. Temperature Impacts the Development and Survival of Common Cutworm (Spodoptera litura: Simulation and Visualization of Potential Population Growth in India under Warmer Temperatures through Life Cycle Modelling and Spatial Mapping.

    Directory of Open Access Journals (Sweden)

    Babasaheb B Fand

    Full Text Available The common cutworm, Spodoptera litura, has become a major pest of soybean (Glycine max throughout its Indian range. With a changing climate, there is the potential for this insect to become an increasingly severe pest in certain regions due to increased habitat suitability. To examine this possibility, we developed temperature-based phenology model for S. litura, by constructing thermal reaction norms for cohorts of single life stages, at both constant and fluctuating temperatures within the ecologically relevant range (15-38°C for its development. Life table parameters were estimated stochastically using cohort updating and rate summation approach. The model was implemented in the geographic information system to examine the potential future pest status of S. litura using temperature change projections from SRES A1B climate change scenario for the year 2050. The changes were visualized by means of three spatial indices demonstrating the risks for establishment, number of generations per year and pest abundance according to the temperature conditions. The results revealed that the development rate as a function of temperature increased linearly for all the immature stages of S. litura until approximately 34-36°C, after which it became non-linear. The extreme temperature of 38°C was found lethal to larval and pupal stages of S. litura wherein no development to the next stage occurred. Females could lay no eggs at the extreme low (15°C and high (> 35°C test temperatures, demonstrating the importance of optimum temperature in determining the suitability of climate for the mating and reproduction in S. litura. The risk mapping predicts that due to temperature increase under future climate change, much of the soybean areas in Indian states like Madhya Pradesh, Maharashtra and Rajasthan, will become suitable for S. litura establishment and increased pest activity, indicating the expansion of the suitable and favourable areas over time. This has

  10. Evaluation of non-azeotropic mixtures containing HFOs as potential refrigerants in refrigeration and high-temperature heat pump systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    With the increasing environmental concern on global warming, hydrofluoro-olefin (HFOs), possessing low GWP, has attracted great attention of many researchers recently. In this study, non-azeotropic mixtures composed of HFOs (HFO-1234yf, HFO-1234ze(z), HFO-1234ze(e) and HFO-1234zf) are developed to substitute for HFC-134a and CFC-114 in air-conditioning and high-temperature heat pump systems, respectively. The cycle performances were evaluated by an improved theoretical cy-cle evaluation methodology. The results showed that all the mixtures proposed herein were favorable refrigerants with excel-lent thermodynamic cycle performances. M1A presented lower discharge temperature and pressure ratio and higher COPc than that of HFC-134a. The volumetric cooling capacity was similar to HFC-134a. It can be served as a good environmentally friendly alternative to replace HFC-134a. M3H delivered similar discharge temperature as CFC-114 did. And the COPh was 3% higher. It exhibits excellent cycle performance in high-temperature heat pump and is a promising refrigerant to substitute for CFC-114. And the gliding temperature differences enable them to exhibit better coefficient of performance by matching the sink/source temperature in practice. Because the toxicity, flammability and other properties are not investigated in detail, ex-tensive toxicity and flammability testing needs to be conducted before they are used in a particular application.

  11. Temperature-dependency analysis and correction methods of in-situ power-loss estimation for crystalline silicon modules undergoing potential-induced degradation stress testing

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Hacke, Peter; Sera, Dezso

    2015-01-01

    We propose a method of in-situ characterization of the photovoltaic module power at standard test conditions using superposition of the dark current-voltage (I-V) curve measured at elevated stress temperature during potential-induced degradation (PID) testing. PID chamber studies were performed...... duration and cost, avoids stress transients while ramping to and from the stress temperature, eliminates flash testing except at the initial and final data points, and enables significantly faster and more detailed acquisition of statistical data for future application of various statistical reliability...... on several crystalline silicon module designs to determine the extent to which the temperature dependency of maximum power is affected by the degradation of the modules. The results using the superposition principle show a mismatch between the power degradation measured at stress temperature and the power...

  12. The effects of constant and alternating temperatures on the reproductive potential, life span, and life expectancy of Anastrepha fraterculus (Wiedemann (Dipteria: Tephritidae

    Directory of Open Access Journals (Sweden)

    V. V. CARDOSO

    Full Text Available Ovarian development, oviposition, larval eclosion, ornithine decarboxylase (ODC activity, ovarian, testis and ejaculatory apodeme measurements (length, width, and area, and the number of spermatozoa of Anastrepha fraterculus (Wiedemann were analyzed at alternating (20º/6ºC and 20º/13°C and constant (6°C; 25°C temperatures. Life span and life expectancy were also analyzed for both genders. All the results suggest that temperature, especially alternating temperatures, increase not only male and female reproductive potential but also their life span and life expectancy. These changes can be a powerful strategy triggered by A. fraterculus as a means to survive the stressful temperature conditions found in winter in the apple production region in Brazil, enabling this species to increase its population density and cause apple damage when spring begins.

  13. The effects of constant and alternating temperatures on the reproductive potential, life span, and life expectancy of Anastrepha fraterculus (Wiedemann (Dipteria: Tephritidae

    Directory of Open Access Journals (Sweden)

    CARDOSO V. V.

    2002-01-01

    Full Text Available Ovarian development, oviposition, larval eclosion, ornithine decarboxylase (ODC activity, ovarian, testis and ejaculatory apodeme measurements (length, width, and area, and the number of spermatozoa of Anastrepha fraterculus (Wiedemann were analyzed at alternating (20masculine/6masculineC and 20masculine/13degreesC and constant (6degreesC; 25degreesC temperatures. Life span and life expectancy were also analyzed for both genders. All the results suggest that temperature, especially alternating temperatures, increase not only male and female reproductive potential but also their life span and life expectancy. These changes can be a powerful strategy triggered by A. fraterculus as a means to survive the stressful temperature conditions found in winter in the apple production region in Brazil, enabling this species to increase its population density and cause apple damage when spring begins.

  14. HOW ARE PLANT SPECIES IN CENTRAL EUROPEAN BEECH (FAGUS SYLVATICA L. FORESTS AFFECTED BY TEMPERATURE CHANGES? SHIFT OF POTENTIAL SUITABLE HABITATS UNDER GLOBAL WARMING

    Directory of Open Access Journals (Sweden)

    M. C. Jantsch

    2013-10-01

    Full Text Available This study reveals which temperature range is favoured or avoided by 156 forest plant species and how the distribution of potential suitable habitats of species in beech forests may change in the future. We performed 140 phytosociological relevés along a temperature gradient (4.1 to 9.8 °C in Bavaria, southern Germany, on south exposed slopes. One half of the plots were located on acidic substrate, the other half on base-rich substrate. Generalized linear models (GLM were used to analyse species occurrence along the temperature gradient and to model habitats for species in beech forests under a present (1971-2000 and a future climate (2071-2100 scenario assuming a temperature increase of 1.8 °C. Herb species of beech forests are more adapted to lower temperatures and tree species more to higher temperatures. Current habitats will clearly change under increasing temperatures. We found large habitat losses for Luzula sylvatica (Huds. Gaudin, Maianthemum bifolium (L. F. W. Schmidt, Picea abies (L. H. Karst., Prenanthes purpurea L. and large habitat gains for Carpinus betulus L., Impatiens parviflora DC., Prunus avium (L. L. and Quercus petraea (Matt. Liebl. on both substrates. Forestry will be affected positively as well as negatively with a change in tree cultivation. Losses in biodiversity might be strong for mountainous forests and must also be considered in future conservation plans.

  15. Potential effects of changes in temperature and food resources on life history trajectories of juvenile Oncorhynchus mykiss

    Science.gov (United States)

    Benjamin, Joseph R.; Connolly, Patrick J.; Romine, Jason G.; Perry, Russell W.

    2013-01-01

    Increasing temperatures and changes in food resources owing to climate change may alter the growth and migratory behavior of organisms. This is particularly important for salmonid species like Oncorhynchus mykiss, where some individuals remain in freshwater to mature (nonanadromous Rainbow Trout) and others migrate to sea (anadromous Steelhead). Whether one strategy is adopted over the other may depend on the individual's growth and size. In this study, we explored (1) how water temperature in Beaver Creek, a tributary to the Methow River, Washington, may increase under four climate scenarios, (2) how these thermal changes may alter the life history trajectory followed by O. mykiss (i.e., when and if to smolt), and (3) how changes in food quality or quantity might interact with increasing temperatures. We combined bioenergetic and state-dependent life history models parameterized for O. mykiss in Beaver Creek to mimic baseline life history trajectories. Based on our simulations, when mean water temperature was increased by 0.6°C there was a reduction in life history diversity and a 57% increase in the number of individuals becoming smolts. When mean temperature was increased by 2.7°C, it resulted in 87% fewer smolts than in the baseline and fewer life history trajectories expressed. A reduction in food resources led to slower growth, more life history trajectories, and a greater proportion of smolts. In contrast, when food resources were increased, fish grew faster, which reduced the proportion of smolts and life history diversity. Our modeling suggests that warmer water temperatures associated with climate change could decrease the life history diversity of O. mykiss in the central portion of their range and thereby reduce resiliency to other disturbances. In addition, changes in food resources could mediate or exacerbate the effect of water temperature on the life history trajectories of O. mykiss.

  16. Biomass Production Potential of a Wastewater Alga Chlorella vulgaris ARC 1 under Elevated Levels of CO2 and Temperature

    Directory of Open Access Journals (Sweden)

    Senthil Chinnasamy

    2009-02-01

    Full Text Available The growth response of Chlorella vulgaris was studied under varying concentrations of carbon dioxide (ranging from 0.036 to 20% and temperature (30, 40 and 50oC. The highest chlorophyll concentration (11 µg mL-1 and biomass (210 µg mL-1, which were 60 and 20 times more than that of C. vulgaris at ambient CO2 (0.036%, were recorded at 6% CO2 level. At 16% CO2 level, the concentrations of chlorophyll and biomass values were comparable to those at ambient CO2 but further increases in the CO2 level decreased both of them. Results showed that the optimum temperature for biomass production was 30oC under elevated CO2 (6%. Although increases in temperature above 30oC resulted in concomitant decrease in growth response, their adverse effects were significantly subdued at elevated CO2. There were also differential responses of the alga, assessed in terms of NaH14CO3 uptake and carbonic anhydrase activity, to increases in temperature at elevated CO2. The results indicated that Chlorella vulgaris grew better at elevated CO2 level at 30oC, albeit with lesser efficiencies at higher temperatures.

  17. Dynamics of ordering in highly degenerate models with anisotropic grain-boundary potential: Effects of temperature and vortex formation

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Flyvbjerg, Henrik; Mouritsen, Ole G.

    1989-01-01

    Monte Carlo computer-simulation techniques are used to elucidate the equilibrium phase behavior as well as the late-stage ordering dynamics of some two-dimensional models with ground-state ordering of a high degeneracy, Q. The models are Q-state Potts models with anisotropic grain......, like the standard Potts models do, nor a wetting of the boundaries, as the standard clock models do. Thermal fluctuations nevertheless cause wetting to occur for not too small temperatures. Specifically, we have studied models with Q=12 and 48. The models are quenched from infinite to zero as well......, for quenches to finite temperatures in the Potts-ordered phase there is a distinct crossover to the classical Lifshitz-Allen-Cahn exponent value, n=1 / 2, for both values of Q. This supports the conjecture that the zero-temperature dynamics for models with soft domain boundaries belong to a special...

  18. Changes in magnitude and frequency of heavy precipitation across China and its potential links to summer temperature

    Science.gov (United States)

    Gu, Xihui; Zhang, Qiang; Singh, Vijay P.; Shi, Peijun

    2017-04-01

    Changes in the magnitude, frequency and timing of heavy precipitation are closely related to the occurrence of floods and droughts, which hold a great deal of significance for management of agricultural irrigation and water resources. Records of daily precipitation and temperature from 728 stations across China were used to assess changes in the magnitude, frequency and timing of heavy precipitation using the Peak-over-Threshold (POT) with 95th percentile as the threshold. Because of the continuous nature of the magnitude and timing of heavy precipitation, the ;change point; method and the modified Mann-Kendall trend test method were used to detect change points (CPs) and slowly-varying changes, respectively. In addition, the segmented regression and Poisson regression methods were used to detect CPs and temporal trends in the frequency of heavy precipitation, respectively, with consideration of the count nature of the data. The results showed that 55% and 36% of the stations had CPs in mean and/or variance of the magnitude and timing, respectively, while the percentage is only 5.8% in the frequency. However, while there is limited evidence of significant trends in the magnitude and timing, strong evidence points to a significant increasing frequency in most regions of China. These changes may be partly explained by changes in summer temperature. Examination of the summer surface temperature records suggests that the areas, where the frequency of heavy precipitation has a significant increase, are also mostly characterized by significant increasing temperature. In addition, trends of the frequency vary between the periods before and after the turn point (TP) of summer temperature trends, especially in northern China where both the summer temperature and the frequency have shifted significantly decreasing trends to significantly increasing trends. A possible interpretation of these findings is that storms tend to be more frequent without significant changes in water

  19. Potential changes in bacterial metabolism associated with increased water temperature and nutrient inputs in tropical humic lagoons.

    Science.gov (United States)

    Scofield, Vinicius; Jacques, Saulo M S; Guimarães, Jean R D; Farjalla, Vinicius F

    2015-01-01

    Temperature and nutrient concentrations regulate aquatic bacterial metabolism. However, few studies have focused on the effect of the interaction between these factors on bacterial processes, and none have been performed in tropical aquatic ecosystems. We analyzed the main and interactive effects of changes in water temperature and N and P concentrations on bacterioplankton production (BP), bacterioplankton respiration (BR) and bacterial growth efficiency (BGE) in tropical coastal lagoons. We used a factorial design with three levels of water temperature (25, 30, and 35°C) and four levels of N and/or P additions (Control, N, P, and NP additions) in five tropical humic lagoons. When data for all lagoons were pooled together, a weak interaction was observed between the increase in water temperature and the addition of nutrients. Water temperature alone had the greatest impact on bacterial metabolism by increasing BR, decreasing BP, and decreasing BGE. An increase of 1°C lead to an increase of ~4% in BR, a decrease of ~0.9% in BP, and a decrease of ~4% in BGE. When data were analyzed separately, lagoons responded differently to nutrient additions depending on Dissolved Organic Carbon (DOC) concentration. Lagoons with lowest DOC concentrations showed the strongest responses to nutrient additions: BP increased in response to N, P, and their interaction, BR increased in response to N and the interaction between N and P, and BGE was negatively affected, mainly by the interaction between N and P additions. Lagoons with the highest DOC concentrations showed almost no significant relationship with nutrient additions. Taken together, these results show that different environmental drivers impact bacterial processes at different scales. Changes of bacterial metabolism related to the increase of water temperature are consistent between lagoons, therefore their consequences can be predicted at a regional scale, while the effect of nutrient inputs is specific to different

  20. l-Leucine acts as a potential agent in reducing body temperature at hatching and affords thermotolerance in broiler chicks.

    Science.gov (United States)

    Han, Guofeng; Yang, Hui; Bahry, Mohammad A; Tran, Phuong V; Do, Phong H; Ikeda, Hiromi; Furuse, Mitsuhiro; Chowdhury, Vishwajit S

    2017-02-01

    Thermal manipulation (TM) of incubation temperature causes metabolic alterations and contributes to improving thermotolerance in chicks post hatching. However, there has been no report on amino acid metabolism during TM and the part it plays in thermotolerance. In this study, we therefore first analyzed free amino acid concentrations in the embryonic brain and liver during TM (38.6°C, 6h/d during embryonic day (ED) 10 to ED 18). It was found that leucine (Leu), phenylalanine and lysine were significantly decreased in the embryonic brain and liver. We then chose l-Leu and other branched-chain amino acids (l-isoleucine (L-Ile) and l-valine (l-Val)) for in ovo injection on ED 7 to reveal their roles in thermoregulation, growth, food intake and thermotolerance in chicks. It was found that in ovo injection of l-Leu, but not of l-Ileu or l-Val, caused a significant decline in body temperature at hatching and increased food intake and body weight gain in broiler chicks. Interestingly, in ovo injection of l-Leu resulted in the acquisition of thermotolerance under high ambient temperature (35±1°C for 180min) in comparison with the control thermoneutral temperature (28±1°C for 180min). These results indicate that the free amino acid concentrations during embryogenesis were altered by TM. l-Leu administration in eggs caused a reduction in body temperature at hatching, and afforded thermotolerance in heat-exposed young chicks, further suggesting that l-Leu may be one of the key metabolic factors involved in controlling body temperature in embryos, as well as in producing thermotolerance after hatching.

  1. Time and temperature affect glycolysis in blood samples regardless of fluoride-based preservatives: a potential underestimation of diabetes.

    Science.gov (United States)

    Stapleton, Mary; Daly, Niamh; O'Kelly, Ruth; Turner, Michael J

    2017-01-01

    Background The inhibition of glycolysis prior to glucose measurement is an important consideration when interpreting glucose tolerance tests. This is particularly important in gestational diabetes mellitus where prompt diagnosis and treatment is essential. A study was planned to investigate the effect of preservatives and temperature on glycolysis. Methods Blood samples for glucose were obtained from consented females. Lithium heparin and fluoride-EDTA samples transported rapidly in ice slurry to the laboratory were analysed for glucose concentration and then held either in ice slurry or at room temperature for varying time intervals. Paired fluoride-citrate samples were received at room temperature and held at room temperature, with analysis at similar time intervals. Results No significant difference was noted between mean glucose concentrations when comparing different sample types received in ice slurry. The mean glucose concentrations decreased significantly for both sets of samples when held at room temperature (0.4 mmol/L) and in ice slurry (0.2 mmol/L). A review of patient glucose tolerance tests reported in our hospital indicated that 17.8% exceeded the recommended diagnostic criteria for gestational diabetes mellitus. It was predicted that if the results of fasting samples were revised to reflect the effect of glycolysis at room temperature, the adjusted diagnostic rate could increase to 35.3%. Conclusion Preanalytical handling of blood samples for glucose analysis is vital. Fluoride-EDTA is an imperfect antiglycolytic, even when the samples are transported and analysed rapidly provides such optimal conditions. The use of fluoride-citrate tubes may offer a viable alternative in the diagnosis of diabetes mellitus.

  2. Temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with a soft on-site potential.

    Science.gov (United States)

    Yang, Linlin; Li, Nianbei; Li, Baowen

    2014-12-01

    The temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with soft on-site potential (soft-KG) are investigated systematically. Similarly to the previously studied hard-KG lattices, the existence of renormalized phonons is also confirmed in soft-KG lattices. In particular, the temperature dependence of the renormalized phonon frequency predicted by a classical field theory is verified by detailed numerical simulations. However, the thermal conductivities of soft-KG lattices exhibit the opposite trend in temperature dependence in comparison with those of hard-KG lattices. The interesting thing is that the temperature-dependent thermal conductivities of both soft- and hard-KG lattices can be interpreted in the same framework of effective phonon theory. According to the effective phonon theory, the exponents of the power-law dependence of the thermal conductivities as a function of temperature are only determined by the exponents of the soft or hard on-site potentials. These theoretical predictions are consistently verified very well by extensive numerical simulations.

  3. Temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with a soft on-site potential

    Science.gov (United States)

    Yang, Linlin; Li, Nianbei; Li, Baowen

    2014-12-01

    The temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with soft on-site potential (soft-KG) are investigated systematically. Similarly to the previously studied hard-KG lattices, the existence of renormalized phonons is also confirmed in soft-KG lattices. In particular, the temperature dependence of the renormalized phonon frequency predicted by a classical field theory is verified by detailed numerical simulations. However, the thermal conductivities of soft-KG lattices exhibit the opposite trend in temperature dependence in comparison with those of hard-KG lattices. The interesting thing is that the temperature-dependent thermal conductivities of both soft- and hard-KG lattices can be interpreted in the same framework of effective phonon theory. According to the effective phonon theory, the exponents of the power-law dependence of the thermal conductivities as a function of temperature are only determined by the exponents of the soft or hard on-site potentials. These theoretical predictions are consistently verified very well by extensive numerical simulations.

  4. Co{sub x}C nanorod magnets: Highly magnetocrystalline anisotropy with lower Curie temperature for potential applications

    Energy Technology Data Exchange (ETDEWEB)

    El-Gendy, Ahmed A., E-mail: aelgendy@vcu.edu [Department of Chemistry, Virginia Commonwealth University (VCU), Richmond, VA (United States); Nanotechnology and Nanometrology Lab., National Institute for Standards (NIS), Giza (Egypt); Almugaiteeb, Turki [Department of Chemistry, Virginia Commonwealth University (VCU), Richmond, VA (United States); Carpenter, Everett E., E-mail: ecarpenter2@vcu.edu [Department of Chemistry, Virginia Commonwealth University (VCU), Richmond, VA (United States)

    2013-12-15

    Magnetic Co{sub x}C nanorods with larger magnetocrystalline anisotropy of 5×10{sup 5} J/m{sup 3} as well as larger coercivity and lower Curie temperature are introduced. The particles have an average diameter of 8 nm and shows three different magnetic behaviors. The sample shows ferromagnetism up to 400 K, superparamagnetism at temperature >400 K and

  5. Simulating potential structural and operational changes for Detroit Dam on the North Santiam River, Oregon, for downstream temperature management

    Science.gov (United States)

    Buccola, Norman L.; Rounds, Stewart A.; Sullivan, Annett B.; Risley, John C.

    2012-01-01

    Detroit Dam was constructed in 1953 on the North Santiam River in western Oregon and resulted in the formation of Detroit Lake. With a full-pool storage volume of 455,100 acre-feet and a dam height of 463 feet, Detroit Lake is one of the largest and most important reservoirs in the Willamette River basin in terms of power generation, recreation, and water storage and releases. The U.S. Army Corps of Engineers operates Detroit Dam as part of a system of 13 reservoirs in the Willamette Project to meet multiple goals, which include flood-damage protection, power generation, downstream navigation, recreation, and irrigation. A distinct cycle in water temperature occurs in Detroit Lake as spring and summer heating through solar radiation creates a warm layer of water near the surface and isolates cold water below. Controlling the temperature of releases from Detroit Dam, therefore, is highly dependent on the location, characteristics, and usage of the dam's outlet structures. Prior to operational changes in 2007, Detroit Dam had a well-documented effect on downstream water temperature that was problematic for endangered salmonid fish species, releasing water that was too cold in midsummer and too warm in autumn. This unnatural seasonal temperature pattern caused problems in the timing of fish migration, spawning, and emergence. In this study, an existing calibrated 2-dimensional hydrodynamic water-quality model [CE-QUAL-W2] of Detroit Lake was used to determine how changes in dam operation or changes to the structural release points of Detroit Dam might affect downstream water temperatures under a range of historical hydrologic and meteorological conditions. The results from a subset of the Detroit Lake model scenarios then were used as forcing conditions for downstream CE-QUAL-W2 models of Big Cliff Reservoir (the small reregulating reservoir just downstream of Detroit Dam) and the North Santiam and Santiam Rivers. Many combinations of environmental, operational, and

  6. Effects of Temperature, Relative Humidity, Absolute Humidity, and Evaporation Potential on Survival of Airborne Gumboro Vaccine Virus

    NARCIS (Netherlands)

    Zhao, Y.; Aarnink, A.J.A.; Dijkman, R.; Fabri, T.; Jong, de M.C.M.; Groot Koerkamp, P.W.G.

    2012-01-01

    Survival of airborne virus influences the extent of disease transmission via air. How environmental factors affect viral survival is not fully understood. We investigated the survival of a vaccine strain of Gumboro virus which was aerosolized at three temperatures (10°C, 20°C, and 30°C) and two rela

  7. Maximum Potential of the Car Cabin Temperature in the Outdoor Parking Conditions as a Source of Energy in Thermoelectric Generator

    Science.gov (United States)

    Sunawar, A.; Garniwa, I.

    2017-03-01

    Cars using the principle of converting heat energy into mechanical energy, but a lot of wasted heat energy not entirely transformed into mechanical energy, studies have been conducted that converts the heat energy into electrical energy using the principle thermoelectrically. However, there are many other energies that can be harnessed from the car, such as when the car is parked in the sun or driving in the heat of the sun, the temperature in the cabin can reach 80 degrees Celsius. The heat can be harmful to humans and the children immediately into the vehicle, as well as for the goods stored in the cabin if it contains toxins can evaporate because of the heat and dangerous. The danger can be prevented by reducing the heat in the cabin and transform into other forms of energy such as electricity. By providing a temperature difference of 40 degrees on the cold side of the module can be acquired electricity thermoelectrically up to 0.17W for one of its module, if it is made a module block the energy produced is enough to lower the temperature and charge batteries for further cooling. This study will use experiment method to get the maximum drop in temperature in the car cabin

  8. Auxiliary Heating of Geothermally Preheated Water or CO2 - A Potential Solution for Low- to Moderate-Temperature Geothermal Resources

    Science.gov (United States)

    Kong, X.; Garapati, N.; Adams, B. M.; Randolph, J.; Kuehn, T. H.; Saar, M. O.

    2015-12-01

    Typically, low- to moderate-temperature geothermal resources are more effectively used for direct heat energy applications. However, due to high thermal losses during transport, direct use requires that the heat resource is located near the user. Alternatively, we show here that if such a low-temperature geothermal resource is combined with an additional or secondary energy resource, the power production is increased compared to the sum from two separate (geothermal and secondary fuel) power plants (DiPippo et al. 1978) and the thermal losses are minimized because the thermal energy is utilized where it is produced. Since Adams et al. (2015) found that using CO2 as a subsurface working fluid produces more net power than brine at low- to moderate-temperature geothermal resource conditions, we compare over a range of parameters the net power and efficiencies of hybrid geothermal power plants that use brine or CO2 as the subsurface working fluid, that are then heated further with a secondary energy source that is unspecified here. Parameters varied include the subsurface working fluid (brine vs. CO2), geothermal reservoir depth (2.5-4.5 km), and turbine inlet temperature (200-600°C) after auxiliary heating. The hybrid power plant is numerically modeled using an iterative coupling approach of TOUGH2-ECO2N/ECO2H (Pruess, 2004) for simulation of the subsurface reservoir and Engineering Equation Solver for well bore fluid flow and surface power plant performance. We find that hybrid power plants that are CO2-based (subsurface) systems have higher thermal efficiencies than the brine based systems at low turbine inlet temperatures. Specifically, our results indicate that geothermal hybrid plants that are CO2-based are more efficient than brine-based systems when the contribution of the geothermal resource energy is higher than 48%.

  9. Influence of storage temperature on growth of Penicillium polonicum and Penicillium glabrum and potential for deterioration of frozen chicken nuggets.

    Science.gov (United States)

    Saccomori, Fernanda; Wigmann, Évelin Francine; Bernardi, Angélica Olivier; Alcano-González, María de Jesús; Copetti, Marina Venturini

    2015-05-04

    The practice of freezing food is one of the main processes used by the industry to prolong the shelf life of foods. Its use has expanded in recent years due to the increased consumption of convenience products, many of which are sold in frozen form. The temperature at which these foods are maintained during marketing in supermarkets or stored in the consumer's home is critical to ensure microbiological stability of products. Temperature abuse can allow microbial growth, especially growth of filamentous psychrophilic fungi. Besides economic losses in the industrial sector due to the return of products and loss of confidence by consumers, the development of fungi in foods is a public health problem due to the possibility of mycotoxin production. The aim of this study was to assess the growth at temperatures of 5, 0, -5 and -18°C for two species of fungi involved in the deterioration of frozen chicken nuggets, Penicillium polonicum (33/12 NGT) and Penicillium glabrum (29/12 NGT), inoculated both in culture medium and in the food. The results demonstrated that P. polonicum was able to form microcolonies on potato dextrose agar plates at 0°C and form visible colonies on the surface of the frozen chicken nuggets kept at -5°C for 120 days, regardless of brand. For P. glabrum the limiting growth temperature was 5°C in the culture medium and 0°C on frozen chicken nuggets, regardless of the brand analyzed. Thus, it is essential to adhere to the storage temperatures recommended to ensure the stability and safety of this food product.

  10. Conformational temperature-dependent behavior of a histone H2AX: a coarse-grained Monte Carlo approach via knowledge-based interaction potentials.

    Science.gov (United States)

    Fritsche, Miriam; Pandey, Ras B; Farmer, Barry L; Heermann, Dieter W

    2012-01-01

    Histone proteins are not only important due to their vital role in cellular processes such as DNA compaction, replication and repair but also show intriguing structural properties that might be exploited for bioengineering purposes such as the development of nano-materials. Based on their biological and technological implications, it is interesting to investigate the structural properties of proteins as a function of temperature. In this work, we study the spatial response dynamics of the histone H2AX, consisting of 143 residues, by a coarse-grained bond fluctuating model for a broad range of normalized temperatures. A knowledge-based interaction matrix is used as input for the residue-residue Lennard-Jones potential.We find a variety of equilibrium structures including global globular configurations at low normalized temperature (T* = 0.014), combination of segmental globules and elongated chains (T* = 0.016,0.017), predominantly elongated chains (T* = 0.019,0.020), as well as universal SAW conformations at high normalized temperature (T* ≥ 0.023). The radius of gyration of the protein exhibits a non-monotonic temperature dependence with a maximum at a characteristic temperature (T(c)* = 0.019) where a crossover occurs from a positive (stretching at T* ≤ T(c)*) to negative (contraction at T* ≥ T(c)*) thermal response on increasing T*.

  11. Conformational temperature-dependent behavior of a histone H2AX: a coarse-grained Monte Carlo approach via knowledge-based interaction potentials.

    Directory of Open Access Journals (Sweden)

    Miriam Fritsche

    Full Text Available Histone proteins are not only important due to their vital role in cellular processes such as DNA compaction, replication and repair but also show intriguing structural properties that might be exploited for bioengineering purposes such as the development of nano-materials. Based on their biological and technological implications, it is interesting to investigate the structural properties of proteins as a function of temperature. In this work, we study the spatial response dynamics of the histone H2AX, consisting of 143 residues, by a coarse-grained bond fluctuating model for a broad range of normalized temperatures. A knowledge-based interaction matrix is used as input for the residue-residue Lennard-Jones potential.We find a variety of equilibrium structures including global globular configurations at low normalized temperature (T* = 0.014, combination of segmental globules and elongated chains (T* = 0.016,0.017, predominantly elongated chains (T* = 0.019,0.020, as well as universal SAW conformations at high normalized temperature (T* ≥ 0.023. The radius of gyration of the protein exhibits a non-monotonic temperature dependence with a maximum at a characteristic temperature (T(c* = 0.019 where a crossover occurs from a positive (stretching at T* ≤ T(c* to negative (contraction at T* ≥ T(c* thermal response on increasing T*.

  12. Annual variations and effects of temperature on Legionella spp. and other potential opportunistic pathogens in tap and shower water

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data contained in this worksheet provides the quantitative detection of potential pathogens for the bathroom water samples used in this study. This dataset is...

  13. Recycling cellulases for cellulosic ethanol production at industrial relevant conditions: potential and temperature dependency at high solid processes.

    Science.gov (United States)

    Lindedam, Jane; Haven, Mai Østergaard; Chylenski, Piotr; Jørgensen, Henning; Felby, Claus

    2013-11-01

    Different versions of two commercial cellulases were tested for their recyclability of enzymatic activity at high dry matter processes (12% or 25% DM). Recyclability was assessed by measuring remaining enzyme activity in fermentation broth and the ability of enzymes to hydrolyse fresh, pretreated wheat straw. Industrial conditions were used to study the impact of hydrolysis temperature (40 or 50°C) and residence time on recyclability. Enzyme recycling at 12% DM indicated that hydrolysis at 50°C, though ideal for ethanol yield, should be kept short or carried out at lower temperature to preserve enzymatic activity. Best results for enzyme recycling at 25% DM was 59% and 41% of original enzyme load for a Celluclast:Novozyme188 mixture and a modern cellulase preparation, respectively. However, issues with stability of enzymes and their strong adsorption to residual solids still pose a challenge for applicable methods in enzyme recycling.

  14. Mathematical modelling in Matlab of the experimental results shows the electrochemical potential difference - temperature of the WC coatings immersed in a NaCl solution

    Science.gov (United States)

    Benea, M. L.; Benea, O. D.

    2016-02-01

    The method used for purchasing the corrosion behaviour the WC coatings deposited by plasma spraying, on a martensitic stainless steel substrate consists in measuring the electrochemical potential of the coating, respectively that of the substrate, immersed in a NaCl solution as corrosive agent. The mathematical processing of the obtained experimental results in Matlab allowed us to make some correlations between the electrochemical potential of the coating and the solution temperature is very well described by some curves having equations obtained by interpolation order 4.

  15. Phase Diagram of One-Dimensional Bosons in an Array of Local Nonlinear Potentials at Zero Temperature

    Institute of Scientific and Technical Information of China (English)

    SHI Yun-Long; ZHANG Yu-Mei; CHEN Hong; WU Xiang

    2001-01-01

    The Gaussian wave functional method is applied to a boson system with an array of local nonlinear potentials cos [βφ(nR)] to study the phase diagram of its ground state. The stable ground state is determined by the renormalized mass μ which is a function of the parameter γ = β2/4π, the strength of potential α and the potential concentration c. In different cases γ γ2, μ can have different multiplicities, the phase diagram in parameter space is thus depicted. The value γ = γ1 depends on the concentration c, for c → 0, it coincides with that of the single impurity model; while γ2 = 2 coincides with the conclusion of the continuous model.``

  16. The first three coefficients in the high temperature series expansion of free energy for simple potential models with hard-sphere cores and continuous tails.

    Science.gov (United States)

    Zhou, Shiqi; Solana, J R

    2013-08-08

    The first three coefficients of the high temperature series expansion (HTSE) of the Helmholtz free energy for a number of simple potential models with hard-sphere cores plus continuous tails are obtained for the first time from Monte Carlo simulations. The potential models considered include Square-well, Sutherland, attractive Yukawa, and triangle-well with different potential ranges, as well as a model potential qualitatively resembling the depletion potential in colloidal dispersions. The simulation data are used to evaluate performance of a recent coupling parameter series expansion (CPSE) in calculating for these coefficients, and a traditional macroscopic compressibility approximation (MCA) for the second-order coefficient only. A comprehensive comparison based on these coefficients from the two theoretical approaches and simulations enables one to conclude that (i) unlike one common experience that the widely used MCA usually underestimates the second-order coefficient, the MCA can both overestimate and underestimate the second-order coefficient, and worsens as the range of the potential decreases; and (ii) in contrast, the CPSE not only reproduce the trends in the density dependence of the perturbation coefficients, even the third one, observed in the simulations, but also the agreement is quantitative in most cases, and this clearly highlights the potential of the CPSE in providing accurate estimations for the higher-order coefficients, thus giving rise to an accurate higher-order HTSE.

  17. Ambient temperature deposition of gallium nitride/gallium oxynitride from a deep eutectic electrolyte, under potential control.

    Science.gov (United States)

    Sarkar, Sujoy; Sampath, S

    2016-05-11

    A ternary, ionically conducting, deep eutectic solvent based on acetamide, urea and gallium nitrate is reported for the electrodeposition of gallium nitride/gallium indium nitride under ambient conditions; blue and white light emitting photoluminescent deposits are obtained under potential control.

  18. Development and Application of Interatomic Potentials for Ultra High Temperature Ceramics (UHTC): ZrB2 and HfB2

    Science.gov (United States)

    Lawson, John W.; Daw, Murray; Bauschlicher

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 are characterized by high melting point, good strength, and reasonable oxidation resistance. These materials are of interest for use as sharp leading edges for hypersonic vehicles among other applications. Progress in computational modeling of UHTCs has been limited in part due to the absence of suitable interatomic potentials. We present a Tersoff style parameterization of such potentials for ZrB2 and HfB2 appropriate for atomistic simulations. Parameters are fit to data generated from ab initio calculations. The accuracy of the potentials is assessed against further ab initio data. As a first non ]trivial application, molecular dynamics simulations are performed to evaluate the thermal conductivity of single crystals and the thermal resistance of high symmetry grain boundaries.

  19. District space heating potential of low temperature hydrothermal geothermal resources in the southwestern United States. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    McDevitt, P.K.; Rao, C.R.

    1978-10-01

    A computer simulation model (GIRORA-Nonelectric) is developed to study the economics of district space heating using geothermal energy. GIRORA-Nonelectric is a discounted cashflow investment model which evaluates the financial return on investment for space heating. This model consists of two major submodels: the exploration for and development of a geothermal anomaly by a geothermal producer, and the purchase of geothermal fluid by a district heating unit. The primary output of the model is a calculated rate of return on investment earned by the geothermal producer. The results of the sensitivity analysis of the model subject to changes in physical and economic parameters are given in this report. Using the results of the economic analysis and technological screening criteria, all the low temperature geothermal sites in Southwestern United States are examined for economic viability for space heating application. The methodology adopted and the results are given.

  20. A Low Temperature Eutectic Methane-Ethane Liquid: A Potential Geologic Fluid in the Outermost Solar System

    Science.gov (United States)

    Thompson, Garrett Leland; Hanley, Jennifer; Grundy, Will; Tegler, Stephen C.; Roe, Henry G.; Lindberg, Gerrick Eugene; Trilling, David E.

    2016-10-01

    Many icy bodies and moons in the solar system contain methane and ethane, including Titan, Triton, Pluto, Eris, Makemake, and likely others. The material properties of these species and their interactions with one another are still inadequately characterized. To provide insight into the behaviors of these species we conducted a series of laboratory experiments to map the liquidus line as a function of temperature and composition. The interaction of ethane and methane yields a eutectic mixture and depresses the freezing point to ~72 K, almost 20 K colder than the normal freezing points of either pure species. The eutectic composition is 64% CH4 and 36% C2H6. This phenomenon may enable geological processes involving liquids in the near surface environments of bodies once thought too cold and/or that have surface pressures too low to support liquid phases. The addition of other cosmochemically abundant species may suppress freezing points even further (see Hanley et al., this conference).

  1. Long-term variations in outgoing long-wave radiation (OLR), convective available potential energy (CAPE) and temperature in the tropopause region over India

    Indian Academy of Sciences (India)

    R Sapra; S K Dhaka; V Panwar; R Bhatnagar; K Praveen Kumar; Y Shibagaki; M Venkat Ratnam; M Takahashi

    2011-10-01

    Relationship of outgoing long-wave radiation (OLR) with convective available potential energy (CAPE) and temperature at the 100-hPa pressure level is examined using daily radiosonde data for a period 1980–2006 over Delhi (28.3° N, 77.1°E) and Kolkata (22.3°N, 88.2°E), and during 1989–2005 over Cochin (10°N, 77°E) and Trivandrum (8.5°N, 77.0°E), India. Correlation coefficient (xy) between monthly OLR and CAPE shows a significant (∼ −0.45) anti-correlation at Delhi and Kolkata suggesting low OLR associated with high convective activity during summer (seasonal variation). Though, no significant correlation was found between OLR and CAPE at Cochin and Trivandrum (low latitude region); analysis of OLR and temperature (at 100-hPa) association suggests that low OLR peaks appear corresponding to low temperature at Delhi (xy ∼ 0.30) and Kolkata (xy ∼ 0.25) during summer. However, xy between OLR and temperature becomes opposite as we move towards low latitudes (∼8° – 10°N) due to strong solar cycle influence. Large scale components mainly ENSO and quasi-biennial oscillaton (QBO) that contributed to the 100-hPa temperature variability were also analyzed, which showed that ENSO variance is larger by a factor of two in comparison to QBO over Indian region. ENSO warm conditions cause warming at 100-hPa over Delhi and Darwin. However, due to strong QBO and solar signals in the equatorial region, ENSO signal seems less effective. QBO, ENSO, and solar cycle contribution in temperature are found location-dependent (latitudinal variability) responding in consonance with shifting in convective activity regime during El Niño, seasonal variability in the tropical easterly jet, and the solar irradiance.

  2. Anaerobic fermentation combined with low-temperature thermal pretreatment for phosphorus-accumulating granular sludge: Release of carbon source and phosphorus as well as hydrogen production potential.

    Science.gov (United States)

    Zou, Jinte; Li, Yongmei

    2016-10-01

    Releases of organic compounds and phosphorus from phosphorus-accumulating granular sludge (PGS) and phosphorus-accumulating flocculent sludge (PFS) during low-temperature thermal pretreatment and anaerobic fermentation were investigated. Meanwhile, biogas production potential and microbial community structures were explored. The results indicate that much more soluble chemical oxygen demand (SCOD) and phosphorus were released from PGS than from PFS via low-temperature thermal pretreatment because of the higher extracellular polymeric substances (EPS) content in PGS and higher ratio of phosphorus reserved in EPS. Furthermore, PGS contains more anaerobes and dead cells, resulting in much higher SCOD and volatile fatty acids release from PGS than those from PFS during fermentation. PGS fermentation facilitated the n-butyric acid production, and PGS exhibited the hydrogen production potential during fermentation due to the presence of hydrogen-producing bacteria. Therefore, anaerobic fermentation combined with low-temperature thermal pretreatment can facilitate the recovery of carbon and phosphorus as well as producing hydrogen from PGS.

  3. Estimation of potential evapotranspiration from extraterrestrial radiation, air temperature and humidity to assess future climate change effects on the vegetation of the Northern Great Plains, USA

    Science.gov (United States)

    King, David A.; Bachelet, Dominique M.; Symstad, Amy J.; Ferschweiler, Ken; Hobbins, Michael

    2014-01-01

    The potential evapotranspiration (PET) that would occur with unlimited plant access to water is a central driver of simulated plant growth in many ecological models. PET is influenced by solar and longwave radiation, temperature, wind speed, and humidity, but it is often modeled as a function of temperature alone. This approach can cause biases in projections of future climate impacts in part because it confounds the effects of warming due to increased greenhouse gases with that which would be caused by increased radiation from the sun. We developed an algorithm for linking PET to extraterrestrial solar radiation (incoming top-of atmosphere solar radiation), as well as temperature and atmospheric water vapor pressure, and incorporated this algorithm into the dynamic global vegetation model MC1. We tested the new algorithm for the Northern Great Plains, USA, whose remaining grasslands are threatened by continuing woody encroachment. Both the new and the standard temperature-dependent MC1 algorithm adequately simulated current PET, as compared to the more rigorous PenPan model of Rotstayn et al. (2006). However, compared to the standard algorithm, the new algorithm projected a much more gradual increase in PET over the 21st century for three contrasting future climates. This difference led to lower simulated drought effects and hence greater woody encroachment with the new algorithm, illustrating the importance of more rigorous calculations of PET in ecological models dealing with climate change.

  4. Ultraweak Photon Emission from the Seed Coat in Response to Temperature and Humidity-A Potential Mechanism for Environmental Signal Transduction in the Soil Seed Bank.

    Science.gov (United States)

    Footitt, Steven; Palleschi, Simonetta; Fazio, Eugenio; Palomba, Raffaele; Finch-Savage, William E; Silvestroni, Leopoldo

    2016-09-01

    Seeds beneath the soil sense the changing environment to time germination and seedling emergence with the optimum time of year for survival. Environmental signals first impact with the seed at the seed coat. To investigate whether seed coats have a role in environmental sensing we investigated their ultraweak photon emission (UPE) under the variable temperature, relative humidity and oxygen conditions they could experience in the soil seed bank. Using a custom-built luminometer we measured UPE intensity and spectra (300-700 nm) from Phaseolus vulgaris seeds, seed coats and cotyledons. UPE was greatest from the internal surface of the seed coat. Seed coat UPE increased concomitantly with both increasing temperature and decreasing relative humidity. Emission was oxygen dependent and it was abolished by treatment with dinitrophenylhydrazine, demonstrating the key role of seed coat carbonyls in the phenomenon. We hypothesize that beneath the soil surface the attenuation of light (virtual darkness: low background noise) enables seeds to exploit UPE for transducing key environmental variables in the soil (temperature, humidity and oxygen) to inform them of seasonal and local temperature patterns. Overall, seed coats were found to have potential as effective transducers of key fluctuating environmental variables in the soil.

  5. Novel room temperature synthesis of ZnO nanosheets, characterization and potentials in light harvesting applications and electrochemical devices.

    Science.gov (United States)

    Mansournia, Mohammadreza; Rafizadeh, Somayeh; Hosseinpour-Mashkani, S Mostafa; Motaghedifard, Mohammad Hassan

    2016-08-01

    Zinc oxide nanosheets (ZnONSs) were successfully synthesized using Zn(NO3)2·4H2O as the starting reagent in ammonia atmosphere at room temperature by a novel gas-solution precipitation method. XRD and EDS patterns indicated that pure ZnONSs were produced only in 15min reaction time. Besides, investigating the optical properties of the as-prepared ZnO nanosheets using UV-Vis diffused reflectance spectroscopy (DRS) exhibited their semiconducting property by revealing one optical band gap in 3.3eV. Moreover, rhodamine B and methylene blue degradation were used as a probe reaction to test the as-synthesized ZnONSs photoactivity. Furthermore, a possible reaction mechanism for ZnONSs formation was discussed. On the other hand, operation of ZnONSs in Dye-sensitized solar cell (DSSC) was investigated by current density-voltage (Jsc-Voc) curve. Finally, a pencil graphite electrode was decorated using ZnONSs and pure MWCNT to provide an electrochemical device for Pb(+2) ions sensing. This modified electrode showed agreeable responses to trace amounts of Pb(+2) in NaOAC/HOAC buffer solutions. The limit of detection was found to be 0.112nmolL(-1) for Pb(+2).

  6. Increased temperature, but not acidification, enhances fertilization and development in a tropical urchin: potential for adaptation to a tropicalized eastern Australia

    Science.gov (United States)

    Foo, Shawna A; Dworjanyn, Symon A; Khatkar, Mehar S; Poore, Alistair G B; Byrne, Maria

    2014-01-01

    To predict the effects of global change on marine populations, it is important to measure the effects of climate stressors on performance and potential for adaptation. Adaptation depends on heritable genetic variance for stress tolerance being present in populations. We determined the effects of near-future ocean conditions on fertilization success of the sea urchin Pseudoboletia indiana. In 16 multiple dam-sire crosses, we quantified genetic variation in tolerance of warming (+3°C) and acidification (−0.3 to 0.5 pH units) at the gastrulation stage. Ocean acidification decreased fertilization across all dam-sire combinations with effects of pH significantly differing among the pairings. Decreased pH reduced the percentage of normal gastrulae with negative effects alleviated by increased temperature. Significant sire by environment interactions indicated the presence of heritable variation in tolerance of stressors at gastrulation and thus the potential for selection of resistant genotypes, which may enhance population persistence. A low genetic correlation indicated that genotypes that performed well at gastrulation in low pH did not necessarily perform well at higher temperatures. Furthermore, performance at fertilization was not necessarily a good predictor of performance at the later stage of gastrulation. Southern range edge populations of Pseudoboletia indiana may benefit from future warming with potential for extension of their distribution in south-east Australia. PMID:25558283

  7. Half-cell potential mapping to assess repair work on RC structures

    Energy Technology Data Exchange (ETDEWEB)

    Elsener, B. [Cagliari Univ., Dept. of Materials Science (Italy)

    2000-07-01

    Results on the successful use and on the limitations of half-cell potential mapping as an assessment technique after completion of repair work on a concrete structure are reviewed. Examples of repair discussed include traditional repair, electrochemical chloride removal, electrochemical realkalization and the application of surface applied corrosion inhibitors. Results indicate that half-cell potential measurements after traditional repair work or electrochemical chloride removal provide direct evidence of repassivation of the rebars when performed several weeks after the repair work (readings during the first few days after repair tend to show very negative potentials). Special attention must be given to the use of polymer-modified mortars when used in surface treatment of rebars; half-cell potential could remain permanently negative due to restricted oxygen access. Half-cell potential measurements are not considered effective in measuring the efficiency and durability of surface applied corrosion inhibitors due to pore solution pH and composition, and the mostly unknown mechanism of action of inhibitor blends. 18 refs., 8 figs.

  8. The potential effects of concurrent increases in temperature, CO sub 2 and O sub 3 on net photosynthesis, as mediated by rubisCO

    Energy Technology Data Exchange (ETDEWEB)

    Long, S. (Brookhaven National Lab., Upton, NY (United States) Essex Univ., Colchester (United Kingdom). Dept. of Biology)

    1992-07-01

    At the leaf level, under light saturating and light limiting conditions, it is shown that elevated atmospheric CO{sub 2} concentration not only alters the scale of the response of carbon gain to rising temperature, but can alter the direction of response. These points bring into serious question the value of any predictions of plant production which ignore not only the direct effect Of C0{sub 2} on carbon gain, but also the basic interactions of temperature, C0{sub 2} and 0{sub 3}. Whilst many factors may potentially diminish the enhancement of lightsaturated leaf photosynthetic rates with increase in atmospheric CO{sub 2} concentrations, no mechanism has so far been identified which could remove the parallel stimulation of light-limited photosynthesis.

  9. The potential effects of concurrent increases in temperature, CO{sub 2} and O{sub 3} on net photosynthesis, as mediated by rubisCO

    Energy Technology Data Exchange (ETDEWEB)

    Long, S. [Brookhaven National Lab., Upton, NY (United States)]|[Essex Univ., Colchester (United Kingdom). Dept. of Biology

    1992-07-01

    At the leaf level, under light saturating and light limiting conditions, it is shown that elevated atmospheric CO{sub 2} concentration not only alters the scale of the response of carbon gain to rising temperature, but can alter the direction of response. These points bring into serious question the value of any predictions of plant production which ignore not only the direct effect Of C0{sub 2} on carbon gain, but also the basic interactions of temperature, C0{sub 2} and 0{sub 3}. Whilst many factors may potentially diminish the enhancement of lightsaturated leaf photosynthetic rates with increase in atmospheric CO{sub 2} concentrations, no mechanism has so far been identified which could remove the parallel stimulation of light-limited photosynthesis.

  10. Corrosion of 310 stainless steel in H2-H2O-H2S gas mixtures: Studies at constant temperature and fixed oxygen potential

    Science.gov (United States)

    Rao, D. B.; Jacob, K. T.; Nelson, H. G.

    1981-01-01

    Corrosion of SAE 310 stainless steel in H2-H2O-H2S gas mixtures was studied at a constant temperature of 1150 K. Reactive gas mixtures were chosen to yield a constant oxygen potential of approximately 6 x 10 to the minus 13th power/cu Nm and sulfur potentials ranging from 0.19 x 10 to the minus 2nd power/cu Nm to 33 x 10 to the minus 2nd power/cu Nm. The kinetics of corrosion were determined using a thermobalance, and the scales were analyzed using metallography, scanning electron microscopy, and energy dispersive X-ray analysis. Two corrosion regimes, which were dependent on sulfur potential, were identified. At high sulfur potentials (p sub S sub 2 less than or equal to 2.7 x 10 to the minus 2nd power/cu Nm) the corrosion rates were high, the kinetics obeyed a linear rate equation, and the scales consisted mainly of sulfide phases similar to those observed from pure sulfication. At low sulfur potentials (P sub S sub 2 less than or equal to 0.19 x 10 to the minus 2nd power/cu Nm) the corrosion rates were low, the kinetics obeyed a parabolic rate equation, and scales consisted mainly of oxide phases.

  11. High NDVI and Potential Canopy Photosynthesis of South American Subtropical Forests despite Seasonal Changes in Leaf Area Index and Air Temperature

    Directory of Open Access Journals (Sweden)

    Piedad M. Cristiano

    2014-02-01

    Full Text Available The canopy photosynthesis and carbon balance of the subtropical forests are not well studied compared to temperate and tropical forest ecosystems. The main objective of this study was to assess the seasonal dynamics of Normalized Difference Vegetation Index (NDVI and potential canopy photosynthesis in relation to seasonal changes in leaf area index (LAI, chlorophyll concentration, and air temperatures of NE Argentina subtropical forests throughout the year. We included in the analysis several tree plantations (Pinus, Eucalyptus and Araucaria species that are known to have high productivity. Field studies in native forests and tree plantations were conducted; stem growth rates, LAI and leaf chlorophyll concentration were measured. MODIS satellite-derived LAI (1 km SIN Grid and NDVI (250m SIN Grid from February 2000 to 2012 were used as a proxy of seasonal dynamics of potential photosynthetic activity at the stand level. The remote sensing LAI of the subtropical forests decreased every year from 6 to 5 during the cold season, similar to field LAI measurements, when temperatures were 10 °C lower than during the summer. The yearly maximum NDVI values were observed during a few months in autumn and spring (March through May and November, respectively because high and low air temperatures may have a small detrimental effect on photosynthetic activity during both the warm and the cold seasons. Leaf chlorophyll concentration was higher during the cold season than the warm season which may have a compensatory effect on the seasonal variation of the NDVI values. The NDVI of the subtropical forest stands remained high and fairly constant throughout the year (the intra-annual coefficient of variation was 1.9%, and were comparable to the values of high-yield tree plantations. These results suggest that the humid subtropical forests in NE Argentina potentially could maintain high canopy photosynthetic activity throughout the year and thus this ecosystem may

  12. Mesopause temperature perturbations caused by infrasonic waves as a potential indicator for the detection of tsunamis and other geo-hazards

    Directory of Open Access Journals (Sweden)

    M. Bittner

    2010-07-01

    Full Text Available Many geo-hazards such as earthquakes, tsunamis, volcanic eruptions, severe weather, etc., produce acoustic waves with sub-audible frequency, so called infrasound. This sound propagates from the surface to the middle and upper atmosphere causing pressure and temperature perturbations. Temperature fluctuations connected with the above mentioned events usually are very weak at the surface, but the amplitude increases with height because of the exponential decrease of atmospheric pressure with increasing altitude. At the mesopause region (80–100 km height signal amplitudes are about two to three orders of magnitude larger than on the ground.

    The GRIPS (GRound-based Infrared P-branch Spectrometer measurement system operated by the German Remote Sensing Data Center of the German Aerospace Center (DLR-DFD derives temperatures of the mesopause region by observing hydroxyl (OH airglow emissions in the near infrared atmospheric emission spectrum originating from a thin layer at approximately 87 km height.

    The GRIPS instrument is in principle suited for the detection of infrasonic signals generated by e.g. tsunamis and other geo-hazards. This is due to the fact that the infrasound caused by such events should induce observable short-period fluctuations in the OH airglow temperatures. First results obtained during a field campaign performed at the Environmental Research Station "Schneefernerhaus", Zugspitze (47.4° N, 11.0° E from October to December 2008 are presented regarding potential sources of meteorological and orographical origin.

    An adequate distinction of the overlapping infrasonic signatures caused by different infrasound sources in the OH temperature record is needed for the ascription to the proper source. The approach presented here could form a contribution to a hazard monitoring and early warning system.

  13. Analyse of the potential of the high temperature reactor with respect to the use of fissile materials; Analyse des capacites des reacteurs a haute temperature sous l'aspect de l'utilisation des matieres fissiles

    Energy Technology Data Exchange (ETDEWEB)

    Damian, F

    2001-07-01

    The high temperature reactors fuel is made of micro-particles dispersed in a graphite matrix. This configuration makes it possible to reach high burnup, higher than 700 GWj/t. Thanks to the decoupling between the thermal and the neutronic behaviors in the core many types of fuels can be used. These characteristics give to HTR reactor very good capacities to burn fissile materials. This work was done in the frame of the evaluation of HTR capacities to enhance the value of the plutonium stocks. These stocks are currently composed of the irradiated fuels discharged from classical PWR or the dismantling of the nuclear weapons and represent a significant energy potential. These studies concluded that high cycles length can be reached whatever the plutonium quality is (from 50 % to 94 % of fissile plutonium). In addition, it was demonstrated that the moderator temperature coefficient becomes locally positive for highly burn fuel while the core global moderator temperature coefficient remained negative in the operation range of the reactor. A significant share of this work was first devoted to the setting of a modeling of the fuel element but also of the reactor's core with the codes of system SAPHYR. The whole of modeling was validated by reference calculations. This work of code assessment is justified by a preliminary work that showed that the classical calculation scheme used for PWR could not be transposed directly to HTR core. (author)

  14. Fast ionic conduction in tetravalent metal pyrophosphate-alkali carbonate composites: New potential electrolytes for intermediate-temperature fuel cells

    Science.gov (United States)

    Singh, Bhupendra; Bhardwaj, Aman; Gautam, Sandeep K.; Kumar, Devendra; Parkash, Om; Kim, In-Ho; Song, Sun-Ju

    2017-03-01

    Here we present a report on synthesis and characterization of tetravalent metal pyrophosphate (TMP) and alkali carbonate (A2CO3; A = Li and/or Na) composites. The TMP-carbonate composites are prepared by mixing indium-doped tin pyrophosphate or yttrium-doped zirconium pyrophosphate with Li2CO3 or an eutectic mixture of Li2CO3-Na2CO3 in different wt.% ratios. The phase composition, microstructure and electrical conductivity of the sintered specimen are analyzed. In addition, the effect of different TMP and A2CO3 phases is investigated. A maximum ionic conductivity of 5.5 × 10-2 S cm-1 at 630 °C is observed in this study with a Sn0.9In0.1P2O7-Li2CO3 composite. Based on the literature data, TMP-carbonate composites can be considered to be primarily a proton and oxygen-ion co-ionic conductor and, therefore, have strong potential as electrolytes in fuel cells in 500-700 °C range.

  15. 1H NMR metabolic profiling of cod (Gadus morhua larvae: potential effects of temperature and diet composition during early developmental stages

    Directory of Open Access Journals (Sweden)

    Matilde Skogen Chauton

    2015-12-01

    Full Text Available Marine aquaculture offers a great source of protein for the increasing human population, and farming of, for example, Atlantic salmon is a global industry. Atlantic cod farming however, is an example of a promising industry where the potential is not yet realized. Research has revealed that a major bottleneck to successful farming of cod is poor quality of the larvae and juveniles. A large research program was designed to increase our understanding of how environmental factors such as temperature and nutrition affects cod larvae development. Data on larvae growth and development were used together with nuclear magnetic resonance. The NMR data indicated that the temperature influenced the metabolome of the larvae; differences were related to osmolytes such as betaine/TMAO, the amino acid taurine, and creatine and lactate which reflect muscle activity. The larvae were fed Artemia from stage 2, and this was probably reflected in a high taurine content of older larvae. Larvae fed with copepods in the nutrition experiment also displayed a high taurine content, together with higher creatine and betaine/TMAO content. Data on the cod larvae metabolome should be coupled to data on gene expression, in order to identify events which are regulated on the genetic level versus regulation resulting from temperature or nutrition during development, to fully understand how the environment affects larval development.

  16. 1H NMR metabolic profiling of cod (Gadus morhua) larvae: potential effects of temperature and diet composition during early developmental stages

    Science.gov (United States)

    Chauton, Matilde Skogen; Galloway, Trina Falck; Kjørsvik, Elin; Størseth, Trond Røvik; Puvanendran, Velmurugu; van der Meeren, Terje; Karlsen, Ørjan; Rønnestad, Ivar; Hamre, Kristin

    2015-01-01

    ABSTRACT Marine aquaculture offers a great source of protein for the increasing human population, and farming of, for example, Atlantic salmon is a global industry. Atlantic cod farming however, is an example of a promising industry where the potential is not yet realized. Research has revealed that a major bottleneck to successful farming of cod is poor quality of the larvae and juveniles. A large research program was designed to increase our understanding of how environmental factors such as temperature and nutrition affects cod larvae development. Data on larvae growth and development were used together with nuclear magnetic resonance. The NMR data indicated that the temperature influenced the metabolome of the larvae; differences were related to osmolytes such as betaine/TMAO, the amino acid taurine, and creatine and lactate which reflect muscle activity. The larvae were fed Artemia from stage 2, and this was probably reflected in a high taurine content of older larvae. Larvae fed with copepods in the nutrition experiment also displayed a high taurine content, together with higher creatine and betaine/TMAO content. Data on the cod larvae metabolome should be coupled to data on gene expression, in order to identify events which are regulated on the genetic level versus regulation resulting from temperature or nutrition during development, to fully understand how the environment affects larval development. PMID:26545964

  17. Lattice cut-off effects and their reduction in studies of QCD thermodynamics at non-zero temperature and chemical potential

    CERN Document Server

    Hegde, P; Laermann, E; Shcheredin, S

    2008-01-01

    We clarify the relation between the improvement of dispersion relations in the fermion sector of lattice regularized QCD and the improvement of bulk thermodynamic observables. We show that in the infinite temperature limit the cut-off dependence in dispersion relations can be eliminated up to O(a^n) corrections, if the quark propagator is chosen to be rotationally invariant up to this order. In bulk thermodynamic observables this eliminates cut-off effects up to the same order at vanishing as well as non-vanishing chemical potential. We furthermore show, that in the infinite temperature, ideal gas limit the dependence of finite cut-off corrections on the chemical potential is given by Bernoulli polynomials which are universal as they do not depend on a particular discretization scheme. We explicitly calculate leading and next-to-leading order cut-off corrections for some staggered and Wilson fermion type actions and compare these with exact evaluations of the free fermion partition functions. This also includ...

  18. Development of geothermal field following the 2000 eruption of Usu volcano as revealed by ground temperature, resistivity and self-potential variations

    Directory of Open Access Journals (Sweden)

    T. Mogi

    2007-06-01

    Full Text Available The 2000 eruption of Usu volcano, NE Japan, took place on the foot of the somma, and formed a cryptodome of 65 m high accompanying numerous faults. We made repeated measurements of ground temperature, Self-Potential (SP and electrical resistivity, in order to clarify the mechanism of development of the newly formed geothermal field on the fault zone. Prior to the expansion of the geothermal field, we detected a resistive zone at the center of the geothermal zone and it supposed to evidence that the zone involving dry steam phase had been formed beneath the fault zone. A rapid expansion of the geothermal field followed along the fault zone away from the craters. The place of maximum amplitude of the SP field also migrated following the expansion of the high ground temperature zone. The high resistive part has shrunk as a consequence of the progress of condensation to warm the surroundings. Based on the observations, we delineated the process of the hydrothermal circulation. Considering the topographic effect of the SP field observed on the highly permeable zone in the Usu somma, the potential flow along the slope of the soma was expected to play an important role to promote the rapid expansion of the geothermal field and the migration of the most active part.

  19. Replacing critical radiators to increase the potential to use low-temperature district heating – A case study of 4 Danish single-family houses from the 1930s

    DEFF Research Database (Denmark)

    Østergaard, Dorte Skaarup; Svendsen, Svend

    2016-01-01

    radiator sizes and heating demands in 4 existing Danish single-family houses from the 1930s. A year-long dynamic simulation was performed for each of the houses to evaluate the potential to lower the heating system temperatures. The results indicate that there is a large potential to use low-temperature...... district heating in existing single-family houses. In order to obtain the full potential of low-temperature district heating, critical radiators must be replaced. Based on a novel method, a total of nine radiators were identified to be critical to ensure thermal comfort and low return temperatures in two......Low-temperature district heating is a promising technology for providing homes with energy-efficient heating in the future. However, it is of great importance to maintain thermal comfort in existing buildings when district heating temperatures are lowered. This case study evaluated the actual...

  20. Temperature-dependent development and potential distribution of Episimus utilis (Lepidoptera: Tortricidae), a candidate biological control agent of Brazilian peppertree (Sapindales: Anacardiaceae) in Florida.

    Science.gov (United States)

    Manrique, Veronica; Cuda, James P; Overholt, William A; Diaz, Rodrigo

    2008-08-01

    The invasive Brazilian peppertree (Schinus terebinthifolius Raddi), native to South America, is widely established throughout central and south Florida. The defoliating leaflet-roller Episimus utilis Zimmerman was selected as potential biocontrol agent of this invasive species. The objectives of this study were to determine development rate and survival of E. utilis at seven constant temperatures (10, 15, 20, 25, 30, 33, and 35 degrees C) and generate prediction maps of the number of generations per year this species may exhibit in the United States. The rate of development of E. utilis as a function of temperature was modeled using linear regression to estimate a lower developmental threshold of 9.6 degrees C and the degree-day requirement of 588. The Logan nonlinear regression model was used to estimate an upper developmental threshold of 33 degrees C. Cold tolerance of E. utilis was examined using all insect stages, and each stage was exposed to three constant temperatures (10, 5, 0 degrees C) for 0.5, 1, 2, 4, and 8 d (or until all insects died). The pupal stage was the most cold tolerant with 100% mortality after 12 d at 0 degrees C. The pupal lethal times at 5 (Ltime50 = 10 d, Ltime90 = 28 d) and 0 degrees C (Ltime50 = 5 d, Ltime90 = 9 d) were used to generate isothermal lines to predict favorable regions for E. utilis establishment. A GIS map was generated to predict the number of generations of E. utilis (range, 0.5-9.8) across all Brazilian peppertree range in the United States. The potential for establishment of E. utilis and its probable distribution in the continental United States was examined.

  1. Design and Economic Potential of an Integrated High-Temperature Fuel Cell and Absorption Chiller Combined Cooling, Heat, and Power System

    Science.gov (United States)

    Hosford, Kyle S.

    Clean distributed generation power plants can provide a much needed balance to our energy infrastructure in the future. A high-temperature fuel cell and an absorption chiller can be integrated to create an ideal combined cooling, heat, and power system that is efficient, quiet, fuel flexible, scalable, and environmentally friendly. With few real-world installations of this type, research remains to identify the best integration and operating strategy and to evaluate the economic viability and market potential of this system. This thesis informs and documents the design of a high-temperature fuel cell and absorption chiller demonstration system at a generic office building on the University of California, Irvine (UCI) campus. This work details the extension of prior theoretical work to a financially-viable power purchase agreement (PPA) with regard to system design, equipment sizing, and operating strategy. This work also addresses the metering and monitoring for the system showcase and research and details the development of a MATLAB code to evaluate the economics associated with different equipment selections, building loads, and economic parameters. The series configuration of a high-temperature fuel cell, heat recovery unit, and absorption chiller with chiller exhaust recirculation was identified as the optimal system design for the installation in terms of efficiency, controls, ducting, and cost. The initial economic results show that high-temperature fuel cell and absorption chiller systems are already economically competitive with utility-purchased generation, and a brief case study of a southern California hospital shows that the systems are scalable and viable for larger stationary power applications.

  2. The effect of low-temperature pretreatment on the solubilization and biomethane potential of microalgae biomass grown in synthetic and wastewater media.

    Science.gov (United States)

    Kinnunen, V; Rintala, J

    2016-12-01

    Microalgae have been suggested as a sustainable raw material for biofuel production in the form of methane via anaerobic digestion. Here, pretreatments at 60-80°C were investigated, aiming to study the impact of algae culture media on biomethane potential and pretreatment efficiency. Chlorella vulgaris and mixed culture of native algae species (dominating by Scenedesmus sp.) were grown in synthetic medium, wastewater (sterilized and non-sterilized) and digestate from anaerobic digestion of pulp and paper biosludge (sterilized and non-sterilized). The biomethane potential for native microalgal biomass varied between 154 and 252LCH4kg(-1) VS depending on culture media. The efficiency of the low-temperature pretreatment (80°C, 3h) for solubilization (9-12%) of C. vulgaris and native algae biomass was similar for algae grown in sterilized and non-sterilized wastewater media. The pretreatment increased the biomethane potential of native algae biomass by 11-24%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Trace metal/Ca ratios in benthic foraminifera: the potential to reconstruct past variations in temperature and hypoxia in shelf regions

    Directory of Open Access Journals (Sweden)

    J. Groeneveld

    2013-03-01

    Full Text Available Shelf and coastal regions are exceptionally important for many countries as they provide the main habitat for many economically important fish and shellfish species. With ongoing global warming and human-induced eutrophication the shelf regions are especially affected, resulting in increased temperatures and stratification as well as oxygen depletion of the bottom waters. In order to be able to predict the magnitude of these changes in the future it is necessary to study how they varied in the past. Commonly used foraminiferal climate and environmental proxies, e.g. stable isotopes and trace metal/Ca ratios, which are applied in open-ocean settings are not necessarily applicable in shelf regions, either as faunas are completely different or as conditions change a-typical compared to the open-ocean. In this study we explore the use of Mg/Ca as paleothermometer and Mn/Ca as a potential proxy for changing dissolved oxygen conditions on the benthic foraminifera Bulimina marginata and Globobulimina turgida. Living specimens were collected from the Skagerrak and the Gullmar Fjord (SW-Sweden; the latter is hypoxic for several months a year. As the specimens were alive when collected it can be excluded that any diagenetic coatings have affected the trace metal/Ca ratios. The Mg/Ca ratios are similar to previously published values from the literature but display much larger variation than would be expected from the annual temperature change of less than 2 °C. An additional impact of the difference in the carbonate ion saturation state between the Skagerrak and the Gullmar Fjord could explain the results. Mn/Ca ratios on Globobulimina turgida potentially record variations in dissolved oxygen of the habitat where the foraminifera calcify. Samples from the Skagerrak display increased Mn/Ca in specimens which lived deeper in the sediment than those that lived near the surface. Globobulimina turgida samples from the lower oxygen Gullmar Fjord showed

  4. Mg/Ca and Mn/Ca ratios in benthic foraminifera: the potential to reconstruct past variations in temperature and hypoxia in shelf regions

    Directory of Open Access Journals (Sweden)

    J. Groeneveld

    2013-07-01

    Full Text Available Shelf and coastal regions are exceptionally important for many countries as they provide the main habitat for many economically important fish and shellfish species. With ongoing climate change and human-induced eutrophication the shelf regions are especially affected, resulting in increased temperatures and stratification as well as oxygen depletion of the bottom waters. In order to be able to predict the magnitude of these changes in the future, it is necessary to study how they varied in the past. Commonly used foraminiferal climate and environmental proxies, e.g., stable isotopes and trace metal/Ca ratios, that are applied in open-ocean settings are not necessarily applicable in shelf regions, either as faunas are significantly different or as conditions can change much faster compared to the open ocean. In this study we explore the use of Mg/Ca as paleothermometer and Mn/Ca as a potential proxy for changing dissolved oxygen conditions in bottom water on the benthic foraminifera Bulimina marginata and Globobulimina turgida. Living specimens were collected from the Skagerrak and the Gullmar Fjord (SW Sweden; the latter is hypoxic for several months a year. As the specimens were alive when collected, we assume it unlikely that any diagenetic coatings have already significantly affected the trace metal/Ca ratios. The Mg/Ca ratios are similar to previously published values but display much larger variation than would be expected from the annual temperature change of less than 2 °C. An additional impact of the difference in the calcite saturation state between the Skagerrak and the Gullmar Fjord could explain the results. Mn/Ca ratios from G. turgida can potentially be related to variations in dissolved oxygen of the habitat where the foraminifera calcify. Samples from the Skagerrak display increased Mn/Ca in specimens that lived deeper in the sediment than those that lived near the surface. G. turgida samples from the low-oxygen Gullmar Fjord

  5. Sun L-Band Brightness Temperature Estimate from Soil Moisture and Ocean Salinity (SMOS) Mission: A Potential New Space Weather Applications for SMOS Data

    Science.gov (United States)

    Crapolicchio, Raffaele; Capolongo, Emiliano; Bigazzi, Alberto

    2016-08-01

    The paper presents the results of a validation study to assess the potentiality of the Level-1b (L1b) Soil Moisture and Ocean Salinity (SMOS) Sun Brightness Temperature (BT) as a valuable L-band radio signal useful in the space weather context. The validation exercise, done for both eruptive and quite/active Sun, focused on SMOS data availability, coverage and statistical analysis with respect to the United States Air Force (USAF) Radio Solar Telescope Network (RSTN) recorded data. In both cases the comparison of the two data sets has shown a strong timing correlation and an impressive burst amplitude correspondence. The paper also presents main advantages and some caveats in the use of the SMOS dataset. The results obtained encourage to pursue further studies both on the SMOS L1 processing algorithm refinement and on the usage of SMOS BT as an additional, independent and important source of information for space weather applications.

  6. Characterization of Ni19.5Ti50.5Pd25Pt5 High-Temperature Shape Memory Alloy Springs and their Potential Application in Aeronautics

    Science.gov (United States)

    Stebner, Aaron; Padula, Santo A.; Noebe, Ronald D.

    2008-01-01

    Shape memory alloys (SMAs) have been used as actuators in many different industries since the discovery of the shape memory effect, but the use of SMAs as actuation devices in aeronautics has been limited due to the temperature constraints of commercially available materials. Consequently, work is being done at NASA's Glenn Research Center to develop new SMAs capable of being used in high temperature environments. One of the more promising high-temperature shape memory alloys (HTSMAs) is Ni19.5Ti50.5Pd25Pt5. Recent work has shown that this material is capable of being used in operating environments of up to 250 C. This material has been shown to have very useful actuation capabilities, demonstrating repeatable strain recoveries up to 2.5% in the presence of an externally applied load. Based on these findings, further work has been initiated to explore potential applications and alternative forms of this alloy, such as springs. Thus, characterization of Ni19.5Ti50.5Pd25Pt5 springs, including their mechanical response and how variations in this response correlate to changes in geometric parameters, are discussed. The effects of loading history, or training, on spring behavior were also investigated. A comparison of the springs with wire actuators is made and the benefits of using one actuator form as opposed to the other discussed. These findings are used to discuss design considerations for a surge-control mechanism that could be used in the centrifugal compressor of a T-700 helicopter engine.

  7. Characterization of Ni19.5Ti50.5Pd25Pt5 High-Temperature Shape Memory Alloy Springs and their Potential Application in Aeronautics

    Science.gov (United States)

    Stebner, Aaron; Padula, Santo A.; Noebe, Ronald D.

    2008-01-01

    Shape memory alloys (SMAs) have been used as actuators in many different industries since the discovery of the shape memory effect, but the use of SMAs as actuation devices in aeronautics has been limited due to the temperature constraints of commercially available materials. Consequently, work is being done at NASA's Glenn Research Center to develop new SMAs capable of being used in high temperature environments. One of the more promising high-temperature shape memory alloys (HTSMAs) is Ni19.5Ti50.5Pd25Pt5. Recent work has shown that this material is capable of being used in operating environments of up to 250 C. This material has been shown to have very useful actuation capabilities, demonstrating repeatable strain recoveries up to 2.5% in the presence of an externally applied load. Based on these findings, further work has been initiated to explore potential applications and alternative forms of this alloy, such as springs. Thus, characterization of Ni19.5Ti50.5Pd25Pt5 springs, including their mechanical response and how variations in this response correlate to changes in geometric parameters, are discussed. The effects of loading history, or training, on spring behavior were also investigated. A comparison of the springs with wire actuators is made and the benefits of using one actuator form as opposed to the other discussed. These findings are used to discuss design considerations for a surge-control mechanism that could be used in the centrifugal compressor of a T-700 helicopter engine.

  8. Growth potential of Salmonella spp. and Listeria monocytogenes in nine types of ready-to-eat vegetables stored at variable temperature conditions during shelf-life.

    Science.gov (United States)

    Sant'Ana, Anderson S; Barbosa, Matheus S; Destro, Maria Teresa; Landgraf, Mariza; Franco, Bernadette D G M

    2012-06-15

    Growth potential (δ) is defined as the difference between the population of a microorganism at the end of shelf-life of specific food and its initial population. The determination of δ of Salmonella and Listeria monocytogenes in RTE vegetables can be very useful to determine likely threats to food safety. However, little is known on the behavior of these microorganisms in several RTE vegetables. Therefore, the aim of this study was to determine the δ of both pathogens in nine different types of RTE vegetables (escarole, collard green, spinach, watercress, arugula, grated carrot, green salad, and mix for yakisoba) stored at refrigeration (7°C) and abuse temperature (15°C). The population of aerobic microorganisms and lactic acid bacteria, including those showing antimicrobial activity has been also determined. Results indicated that L. monocytogenes was able to grow (δ≥0.5 log(10)) in more storage conditions and vegetables than Salmonella. Both microorganisms were inhibited in carrots, although a more pronounced effect has been observed against L. monocytogenes. The highest δ values were obtained when the RTE vegetables were stored 15°C/6days in collard greens (δ=3.3) and arugula (δ=3.2) (L. monocytogenes) and arugula (δ=4.1) and escarole (δ=2.8) (Salmonella). In most vegetables and storage conditions studied, the counts of total aerobic microorganisms raised significantly independent of the temperature of storage (p<0.05). Counts of lactic acid bacteria were higher in vegetables partially or fully stored at abuse temperature with recovery of isolates showing antimicrobial activity. In conclusion, the results of this study show that Salmonella and L. monocytogenes may grow and reach high populations in RTE vegetables depending on storage conditions and the definition of effective intervention strategies are needed to control their growth in these products.

  9. Temperature and pressure dependent rate coefficients for the reaction of C2H4 + HO2 on the C2H4O2H potential energy surface.

    Science.gov (United States)

    Guo, JunJiang; Xu, JiaQi; Li, ZeRong; Tan, NingXin; Li, XiangYuan

    2015-04-02

    The potential energy surface (PES) for reaction C2H4 + HO2 was examined by using the quantum chemical methods. All rates were determined computationally using the CBS-QB3 composite method combined with conventional transition state theory(TST), variational transition-state theory (VTST) and Rice-Ramsberger-Kassel-Marcus/master-equation (RRKM/ME) theory. The geometries optimization and the vibrational frequency analysis of reactants, transition states, and products were performed at the B3LYP/CBSB7 level. The composite CBS-QB3 method was applied for energy calculations. The major product channel of reaction C2H4 + HO2 is the formation C2H4O2H via an OH(···)π complex with 3.7 kcal/mol binding energy which exhibits negative-temperature dependence. We further investigated the reactions related to this complex, which were ignored in previous studies. Thermochemical properties of the species involved in the reactions were determined using the CBS-QB3 method, and enthalpies of formation of species were compared with literature values. The calculated rate constants are in good agreement with those available from literature and given in modified Arrhenius equation form, which are serviceable in combustion modeling of hydrocarbons. Finally, in order to illustrate the effect for low-temperature ignition of our new rate constants, we have implemented them into the existing mechanisms, which can predict ethylene ignition in a shock tube with better performance.

  10. Adsorption behavior of modified Iron stick yam skin with Polyethyleneimine as a potential biosorbent for the removal of anionic dyes in single and ternary systems at low temperature.

    Science.gov (United States)

    Zhang, Yan-Zhuo; Li, Jun; Zhao, Jing; Bian, Wei; Li, Yun; Wang, Xiu-Jie

    2016-12-01

    The skin of Iron stick yam (ISY) was modified with Polyethyleneimine (ISY@PEI) and evaluated for use as a potential biosorbent to remove the anionic dyes Sunset yellow (SY), Lemon yellow (LY), and Carmine (CM) from wastewater under low temperature conditions (5-15°C) in single and ternary dye systems. Both in the single and ternary systems, experimental data showed that adsorption capacity reached the highest value at 5°C, and adsorption capacity decreased when the temperature increased (10-50°C). The equilibrium data fitted very well to the Langmuir model and the extended Langmuir isotherm, for the single and ternary systems, respectively. The maximum adsorption capability was 138.92, 476.31, and 500.13mg/g for LY, SY, and CM, respectively, in a single system and 36.63, 303.31, and 294.12mg/g for LY, SY, and CM, respectively, in a ternary system. The adsorption followed pseudo-second-order kinetics. The thermodynamic parameters indicated that it was a spontaneous and exothermic process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Study of optimal temperature, pH and stability of dragon fruit (Hylocereus polyrhizus) peel for use as potential natural colorant.

    Science.gov (United States)

    Harivaindaran, K V; Rebecca, O P S; Chandran, S

    2008-09-15

    The peel of Hylocereus polyrhizus is often regarded as a waste hence this study was aimed at exploring the feasibility of using the peel as a natural colorant using simple water extraction method. Samples were subjected to a series of temperatures: Room temperature (RT), 50, 80 and 100 degrees C; varied length of heating time from 1, 2, 3, 4, 5 and 10 min and a varied range of pH using 1 M of citric acid solution. The best condition to obtain highest betacyanin content was heating samples at 100 degrees C for 5 min in a pH 5 citric acid solution. The next part of this study involved the stability test of the pigments obtained through the best method determined earlier. The pigments were dried and resuspended in distilled water. The samples were then exposed to light to monitor pigment changes. Initial resuspension of the dried pigments yielded a comparable high content of betacyanins to its juice counterpart. The results showed that resuspended pigments had high pigment retention and were stable up to 7 days. These initial findings must be further studied in more controlled conditions to understand the stability of betacyanin. Nevertheless, the results show that betacyanin obtained from the peel of dragon fruit has a high potential to be used as a natural dye.

  12. Temperature dependence of the electrode potential of a cobalt-based redox couple in ionic liquid electrolytes for thermal energy harvesting.

    Science.gov (United States)

    He, Jiangjing; Al-Masri, Danah; MacFarlane, Douglas R; Pringle, Jennifer M

    2016-08-15

    Increasing the application of technologies for harvesting waste heat could make a significant contribution to sustainable energy production. Thermoelectrochemical cells are one such emerging technology, where the thermal response of a redox couple in an electrolyte is used to generate a potential difference across a cell when a temperature gradient exists. The unique physical properties of ionic liquids make them ideal for application as electrolytes in these devices. One of the keys to utilizing these media in efficient thermoelectrochemical cells is achieving high Seebeck coefficients, Se: the thermodynamic quantity that determines the magnitude of the voltage achieved per unit temperature difference. Here, we report the Se and cell performance of a cobalt-based redox couple in a range of different ionic liquids, to investigate the influence of the nature of the IL on the thermodynamics and cell performance of the redox system. The results reported include the highest Se to-date for an IL-based electrolyte. The effect of diluting the different ILs with propylene carbonate is also reported, which results in a significant increase in the output powers and current densities of the device.

  13. Second-Harmonic Generation in Vertically Coupled InAs/GaAs Quantum Dots with a Gaussian Potential Distribution: Combined Effects of Electromagnetic Fields, Pressure, and Temperature

    Science.gov (United States)

    Ben Mahrsia, R.; Choubani, M.; Bouzaiene, L.; Maaref, H.

    2015-08-01

    Simulation of quantum dots (QD) is usually performed on the basis of abrupt changes between neighboring materials. In practice, it is not possible to construct such QD because in a real structure the interface between two adjacent materials is not a step. In the work discussed in this paper, vertically coupled InAs/GaAs quantum dots (VCQD) with a non-abrupt change between two neighboring materials are considered. A potential function in the form of a Gaussian distribution was used to show this effect. We also focused on studying the effect of structure, applied electric ( F) and magnetic ( B) fields, pressure ( P), and temperature ( T) on second-harmonic generation (SHG). The analytical expression for SHG was investigated theoretically by use of the density matrix approach, the effective mass, and the finite-difference method (FDM). It was found that the major resonant peak value of SHG is a non-monotonic function of the barrier width ( L B). Moreover, the major resonant peak of SHG is blue-shifted (red-shifted) and its magnitude increases (decreases) monotonically with increasing temperature (pressure). The results obtained also show that the magnitude and position of the resonant peaks of SHG are affected by changes in external conditions, for example applied electric and magnetic fields, structural dimensions of the coupled QD system, and relaxation time ( T 0). Calculations also show that SHG in a VCQD structure with a non-abrupt potential change can be controlled and optimized by appropriate choice of structural dimensions and the external conditions mentioned above.

  14. Hydrotime model can describe the response of common bean (Phaseolus vulgaris L.) seeds to temperature and reduced water potential - doi: 10.4025/actascibiolsci.v35i2.15393

    National Research Council Canada - National Science Library

    Victor José Mendes Cardoso; André Bianconi

    2013-01-01

    .... The cultivars IPR Uirapuru and IAPAR 81 (drought-tolerant), and Grauna and Carioca (not tolerant) were used. The isothermal assays were performed in a temperature gradient block, and the assays with different osmotic potentials...

  15. Influence of Black Annealing Oxide Scale on the Anodic Behavior of Alloy 22

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B; Etien, R A; Gordon, S R; Ilevbare, G O

    2006-05-22

    The resistance of Alloy 22 (N06022) to localized corrosion, mainly crevice corrosion, has been extensively investigated in the last few years. The effect of influencing variables such as temperature, applied potential, chloride concentration and nitrate inhibitor concentration have been addressed previously. At this time, it was important to address the effect an oxide film or scale that forms during the high temperature annealing process or solution heat treatment (SHT) and its subsequent water quenching. Electrochemical tests such as cyclic potentiodynamic polarization (CPP) have been carried out to determine the repassivation potential for localized corrosion and to assess the mode of attack on the specimens. Tests have been carried out in parallel using mill annealed (MA) specimens free from oxide on the surface. The comparative testing was carried out in six different electrolyte solutions at temperatures ranging from 60 C to 100 C. Results show that the repassivation potential of the specimens containing the black anneal oxide film on the surface was practically the same or higher as the repassivation potential for oxide-free specimens.

  16. Modeling low-temperature serpentinization reactions to estimate molecular hydrogen production with implications for potential microbial life on Saturn's moon Enceladus.

    Science.gov (United States)

    Zwicker, Jennifer; Smrzka, Daniel; Taubner, Ruth-Sophie; Bach, Wolfgang; Rittmann, Simon; Schleper, Christa; Peckmann, Jörn

    2017-04-01

    Serpentinization of ultramafic rocks attracts much interest in research on the origin of life on Earth and the search for life on extraterrestrial bodies including icy moons like Enceladus. Serpentinization on Earth occurs in peridotite-hosted systems at slow-spreading mid-ocean ridges, and produces large amounts of molecular hydrogen and methane. These reduced compounds can be utilized by diverse chemosynthetic microbial consortia as a metabolic energy source. Although many hydrothermal vents emit hot and acidic fluids today, it is more likely that life originated in the Archean at sites producing much cooler and more alkaline fluids that allowed for the synthesis and stability of essential organic molecules necessary for life. Therefore, a detailed understanding of water-rock interaction processes during low-temperature serpentinization is of crucial importance in assessing the life-sustaining potential of these environments. In the course of serpentinization, the metasomatic hydration of olivine and pyroxene produces various minerals including serpentine minerals, magnetite, brucite, and carbonates. Hydrogen production only occurs if ferrous iron within iron-bearing minerals is oxidized and incorporated as ferric iron into magnetite. The PHREEQC code was used to model the pH- and temperature-dependent dissolution of olivine and pyroxene to form serpentine, magnetite and hydrogen under pressure and temperature conditions that may exist on Saturn's icy moon Enceladus. Various model setups at 25 and 50°C were run to assess the influence of environmental parameters on hydrogen production. The results reveal that hydrogen production rates depend on the composition of the initial mineral assemblage and temperature. The current assumption is that there is a gaseous phase between Enceladus' ice sheet and subsurface ocean. To test various scenarios, model runs were conducted with and without the presence of a gas phase. The model results show that hydrogen production is

  17. Aboveground carbon in Quebec forests: stock quantification at the provincial scale and assessment of temperature, precipitation and edaphic properties effects on the potential stand-level stocking

    Directory of Open Access Journals (Sweden)

    Louis Duchesne

    2016-03-01

    Full Text Available Biological carbon sequestration by forest ecosystems plays an important role in the net balance of greenhouse gases, acting as a carbon sink for anthropogenic CO2 emissions. Nevertheless, relatively little is known about the abiotic environmental factors (including climate that control carbon storage in temperate and boreal forests and consequently, about their potential response to climate changes. From a set of more than 94,000 forest inventory plots and a large set of spatial data on forest attributes interpreted from aerial photographs, we constructed a fine-resolution map (∼375 m of the current carbon stock in aboveground live biomass in the 435,000 km2 of managed forests in Quebec, Canada. Our analysis resulted in an area-weighted average aboveground carbon stock for productive forestland of 37.6 Mg ha−1, which is lower than commonly reported values for similar environment. Models capable of predicting the influence of mean annual temperature, annual precipitation, and soil physical environment on maximum stand-level aboveground carbon stock (MSAC were developed. These models were then used to project the future MSAC in response to climate change. Our results indicate that the MSAC was significantly related to both mean annual temperature and precipitation, or to the interaction of these variables, and suggest that Quebec’s managed forests MSAC may increase by 20% by 2041–2070 in response to climate change. Along with changes in climate, the natural disturbance regime and forest management practices will nevertheless largely drive future carbon stock at the landscape scale. Overall, our results allow accurate accounting of carbon stock in aboveground live tree biomass of Quebec’s forests, and provide a better understanding of possible feedbacks between climate change and carbon storage in temperate and boreal forests.

  18. Aboveground carbon in Quebec forests: stock quantification at the provincial scale and assessment of temperature, precipitation and edaphic properties effects on the potential stand-level stocking.

    Science.gov (United States)

    Duchesne, Louis; Houle, Daniel; Ouimet, Rock; Lambert, Marie-Claude; Logan, Travis

    2016-01-01

    Biological carbon sequestration by forest ecosystems plays an important role in the net balance of greenhouse gases, acting as a carbon sink for anthropogenic CO2 emissions. Nevertheless, relatively little is known about the abiotic environmental factors (including climate) that control carbon storage in temperate and boreal forests and consequently, about their potential response to climate changes. From a set of more than 94,000 forest inventory plots and a large set of spatial data on forest attributes interpreted from aerial photographs, we constructed a fine-resolution map (∼375 m) of the current carbon stock in aboveground live biomass in the 435,000 km(2) of managed forests in Quebec, Canada. Our analysis resulted in an area-weighted average aboveground carbon stock for productive forestland of 37.6 Mg ha(-1), which is lower than commonly reported values for similar environment. Models capable of predicting the influence of mean annual temperature, annual precipitation, and soil physical environment on maximum stand-level aboveground carbon stock (MSAC) were developed. These models were then used to project the future MSAC in response to climate change. Our results indicate that the MSAC was significantly related to both mean annual temperature and precipitation, or to the interaction of these variables, and suggest that Quebec's managed forests MSAC may increase by 20% by 2041-2070 in response to climate change. Along with changes in climate, the natural disturbance regime and forest management practices will nevertheless largely drive future carbon stock at the landscape scale. Overall, our results allow accurate accounting of carbon stock in aboveground live tree biomass of Quebec's forests, and provide a better understanding of possible feedbacks between climate change and carbon storage in temperate and boreal forests.

  19. Investigation of Device Performance and Negative Bias Temperature Instability of Plasma Nitrided Oxide in Nanoscale p-Channel Metal-Oxide-Semiconductor Field-Effect Transistor's

    Science.gov (United States)

    Han, In-Shik; Ji, Hee-Hwan; Goo, Tae-Gyu; Yoo, Ook-Sang; Choi, Won-Ho; Na, Min-Ki; Kim, Yong-Goo; Park, Sung-Hyung; Lee, Heui-Seung; Kang, Young-Seok; Kim, Dae-Byung; Lee, Hi-Deok

    2008-04-01

    In this paper, we investigated the device performance and negative bias temperature instability (NBTI) degradation for thermally nitrided oxide (TNO) and plasma nitrided oxide (PNO) in nanoscale p-channel metal oxide semiconductor field effect transistor (PMOSFET). PNOs show the improvement of dielectric performance compared to TNO with no change of the device performance. PNOs also show the improvement of NBTI immunity than TNO at low temperature stress, whereas NBTI immunity of PNO with high N concentration can be worse than TNO at high temperature stress. Recovery effect of NBTI degradation of PNO is lower than that of TNO and it is increased as the N concentration is increased in PNO because the dissociated Si dangling bonds and generated positive oxide charges are repassivated and neutralized, respectively. Moreover, complete recovery of ΔVth is dominated by neutralization of positive oxide charges. Therefore, N contents at polycrystalline Si/SiO2 interface as well as N contents at Si/SiO2 interface can affect significantly on NBTI degradation and recovery effect.

  20. Effect of ultrasound, low-temperature thermal and alkali pre-treatments on waste activated sludge rheology, hygienization and methane potential.

    Science.gov (United States)

    Ruiz-Hernando, M; Martín-Díaz, J; Labanda, J; Mata-Alvarez, J; Llorens, J; Lucena, F; Astals, S

    2014-09-15

    Waste activated sludge is slower to biodegrade under anaerobic conditions than is primary sludge due to the glycan strands present in microbial cell walls. The use of pre-treatments may help to disrupt cell membranes and improve waste activated sludge biodegradability. In the present study, the effect of ultrasound, low-temperature thermal and alkali pre-treatments on the rheology, hygienization and biodegradability of waste activated sludge was evaluated. The optimum condition of each pre-treatment was selected based on rheological criteria (reduction of steady state viscosity) and hygienization levels (reduction of Escherichia coli, somatic coliphages and spores of sulfite-reducing clostridia). The three pre-treatments were able to reduce the viscosity of the sludge, and this reduction was greater with increasing treatment intensity. However, only the alkali and thermal conditioning allowed the hygienization of the sludge, whereas the ultrasonication did not exhibit any notorious effect on microbial indicators populations. The selected optimum conditions were as follows: 27,000 kJ/kg TS for the ultrasound, 80 °C during 15 min for the thermal and 157 g NaOH/kg TS for the alkali. Afterward, the specific methane production was evaluated through biomethane potential tests at the specified optimum conditions. The alkali pre-treatment exhibited the greatest methane production increase (34%) followed by the ultrasonication (13%), whereas the thermal pre-treatment presented a methane potential similar to the untreated sludge. Finally, an assessment of the different treatment scenarios was conducted considering the results together with an energy balance, which revealed that the ultrasound and alkali treatments entailed higher costs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Shear and Bulk Viscosities of a Weakly Coupled Quark Gluon Plasma with Finite Chemical Potential and Temperature---Leading-Log Results

    CERN Document Server

    Chen, Jiunn-Wei; Song, Yu-Kun; Wang, Qun

    2012-01-01

    We calculate the shear (eta) and bulk (zeta) viscosities of a weakly coupled quark gluon plasma at the leading-log order with finite temperature T and quark chemical potential mu. We find that the shear viscosity to entropy density ratio eta/s increases monotonically with mu and eventually scales as (mu/T)^2 at large mu. In contrary, zeta/s is insensitive to mu. Both eta/s and zeta/s are monotonically decreasing functions of the quark flavor number N_f when N_f \\geq 2. This property is also observed in pion gas systems. Our perturbative calculation suggests that QCD becomes the most perfect (i.e. with the smallest eta/s) at mu=0 and N_f = 16 (the maximum N_f with asymptotic freedom). It would be interesting to test whether the currently smallest eta/s computed close to the phase transition with mu=0 and N_f = 0 can be further reduced by increasing N_f.

  2. Recovery and Growth Potential of Listeria monocytogenes in Temperature Abused Milkshakes Prepared from Naturally Contaminated Ice Cream Linked to a Listeriosis Outbreak.

    Science.gov (United States)

    Chen, Yi; Allard, Emma; Wooten, Anna; Hur, Minji; Sheth, Ishani; Laasri, Anna; Hammack, Thomas S; Macarisin, Dumitru

    2016-01-01

    The recovery and growth potential of Listeria monocytogenes was evaluated in three flavors of milkshakes (vanilla, strawberry, and chocolate) that were prepared from naturally contaminated ice cream linked to a listeriosis outbreak in the U.S. in 2015, and were subsequently held at room temperature for 14 h. The average lag phase duration of L. monocytogenes was 9.05 h; the average generation time was 1.67 h; and the average population level increase per sample at 14 h was 1.14 log CFU/g. Milkshake flavors did not significantly affect these parameters. The average lag phase duration of L. monocytogenes in milkshakes with initial contamination levels ≤ 3 CFU/g (9.50 h) was significantly longer (P 3 CFU/g (8.60 h). The results highlight the value of using samples that are contaminated with very low levels of L. monocytogenes for recovery and growth evaluations. The behavior of L. monocytogenes populations in milkshakes prepared from naturally contaminated ice cream linked to the listeriosis outbreak should be taken into account when performing risk based analysis using this outbreak as a case study.

  3. Predicting the size- and shape-dependent cohesive energy and order-disorder transition temperature of Co-Pt nanoparticles by embedded-atom-method potential.

    Science.gov (United States)

    Liu, Chenze; Qi, Weihong; Ouyang, Bin; Wang, Xing; Huang, Baiyun

    2013-02-01

    The cohesive energy (CE) of CoPt nanoparticles (NPs) with different sizes and shapes have been calculated by embedded-atom-method (EAM) potential. It is shown that CE of NPs with order or disorder structures decreases with the decrease of particle size, while the shape effects become obvious only at small size. The CE difference per atom between order and disorder structures decreases with the decrease of particle size, indicating that the possibility of order-disorder transition in small size becomes larger compared with these in large size. Significantly, the CE difference varies in proportion to order-disorder transition temperature (T(c)), which suggests that one can predict order-disorder transition of NPs by calculation the cohesive energy. The present calculated T(c) of CoPt NPs is consistent with recent experiments, simulation and theoretical predictions, and the method can also be applied to study the order-disorder transition of FePt, FePd, and so on.

  4. Recovery and growth potential of Listeria monocytogenes in temperature abused milkshakes prepared from naturally contaminated ice cream linked to a listeriosis outbreak

    Directory of Open Access Journals (Sweden)

    Yi eChen

    2016-05-01

    Full Text Available The recovery and growth potential of Listeria monocytogenes was evaluated in three flavors of milkshakes (vanilla, strawberry, and chocolate that were prepared from naturally contaminated ice cream linked to a listeriosis outbreak in the U.S. in 2015, and were subsequently held at room temperature for 14 hours. The average lag phase duration of L. monocytogenes was 9.05 h; the average generation time was 1.67 h; and the average level increase per sample at 14 h was 1.15 log CFU/g. Milkshake flavors did not significantly affect these parameters. The average lag phase duration of L. monocytogenes in milkshakes with initial contamination levels ≤ 3 CFU/g (9.50 h was significantly longer (P 3 CFU/g (8.60 h. The results highlight the value of using samples that are contaminated with very low levels of L. monocytogenes for recovery and growth evaluations. The behavior of L. monocytogenes populations in milkshakes prepared from naturally contaminated ice cream linked to the listeriosis outbreak should be taken into account when performing risk based analysis using this outbreak as a case-study.

  5. On a general definition of the squared Brunt-V\\"{a}is\\"{a}l\\"{a} Frequency associated with the specific moist entropy potential temperature

    CERN Document Server

    Marquet, Pascal

    2014-01-01

    The squared Brunt-V\\"{a}is\\"{a}l\\"{a} Frequency (BVF) is computed in terms of the moist entropy potential temperature recently defined in Marquet (2011). Both homogeneously saturated and non-saturated versions of $N^2$ (the squared BVF) are derived. The method employed for computing these special homogeneous cases relies on the expression of density written as a function of pressure, total water content and specific moist entropy only. The associated conservative variable diagrams are discussed and compared with existing ones. Despite being obtained without any simplification, the formulations for $N^2$ remain nicely compact and are clearly linked with the squared BVF expressed in terms of the adiabatic non-saturated and saturated lapse rates. As in previous similar expressions, the extreme homogeneous solutions for $N^2$ are of course different, but they are not analytically discontinuous. This allows us to define a simple bridging expression for a single general shape of $N^2$, depending only on the basic m...

  6. Elastic collisions between Si and D atoms at low temperatures and accurate analytic potential energy function and molecular constants of the SiD(X2∏) radical

    Institute of Scientific and Technical Information of China (English)

    Shi De-Heng; Zhang Jin-Ping; Sun Jin-Feng; Zhu Zun-Lue

    2009-01-01

    Interaction potential of the SiD(X2∏) radical is constructed by using the CCSD(T) theory in combination with the largest correlation-consistent quintuple basis set augmented with the diffuse functions in the valence range. Using the interaction potential, the spectroscopic parameters are accurately determined. The present D0, De, Re, ωe, αe and Be values are of 3.0956 eV, 3.1863 eV, 0.15223 nm, 1472.894 cm-1, 0.07799 cm-1 and 3.8717 cm-1, respectively,which are in excellent agreement with the measurements. A total of 26 vibrational states is predicted when J = 0 by solving the radial Schr(o)dinger equation of nuclear motion. The complete vibrational levels, classical turning points,initial rotation and centrifugal distortion constants when J = 0 are reported for the first time, which are in good accord with the available experiments. The total and various partial-wave cross sections are calculated for the elastic collisions between Si and D atoms in their ground states at 1.0×10-11-1.0×10-3 a.u. when the two atoms approach each other along the SiD(X2∏) potential energy curve. Four shape resonances are found in the total elastic cross sections, and their resonant energies are of 1.73×10-5, 4.0×10-5, 6.45×10-5 and 5.5×10-4 a.u., respectively. Each shape resonance in the total elastic cross sections is carefully investigated. The results show that the shape of the total elastic cross sections is mainly dominated by the s partial wave at very low temperatures. Because of the weakness of the shape resonances coming from the higher partial waves, most of them are passed into oblivion by the strong s partial-wave elastic cross sections.

  7. Indoor Temperatures in Patient Waiting Rooms in Eight Rural Primary Health Care Centers in Northern South Africa and the Related Potential Risks to Human Health and Wellbeing

    Directory of Open Access Journals (Sweden)

    Caradee Y. Wright

    2017-01-01

    Full Text Available Increased temperatures affect human health and vulnerable groups including infants, children, the elderly and people with pre-existing diseases. In the southern African region climate models predict increases in ambient temperature twice that of the global average temperature increase. Poor ventilation and lack of air conditioning in primary health care clinics, where duration of waiting time may be as long as several hours, pose a possible threat to patients seeking primary health care. Drawing on information measured by temperature loggers installed in eight clinics in Giyani, Limpopo Province of South Africa, we were able to determine indoor temperatures of waiting rooms in eight rural primary health care facilities. Mean monthly temperature measurements inside the clinics were warmer during the summer months of December, January and February, and cooler during the autumn months of March, April and May. The highest mean monthly temperature of 31.4 ± 2.7 °C was recorded in one clinic during February 2016. Maximum daily indoor clinic temperatures exceeded 38 °C in some clinics. Indoor temperatures were compared to ambient (outdoor temperatures and the mean difference between the two showed clinic waiting room temperatures were higher by 2–4 °C on average. Apparent temperature (AT incorporating relative humidity readings made in the clinics showed ‘realfeel’ temperatures were >4 °C higher than measured indoor temperature, suggesting a feeling of ‘stuffiness’ and discomfort may have been experienced in the waiting room areas. During typical clinic operational hours of 8h00 to 16h00, mean ATs fell into temperature ranges associated with heat–health impact warning categories of ‘caution’ and ‘extreme caution’.

  8. Indoor Temperatures in Patient Waiting Rooms in Eight Rural Primary Health Care Centers in Northern South Africa and the Related Potential Risks to Human Health and Wellbeing

    Science.gov (United States)

    Wright, Caradee Y.; Street, Renée A.; Cele, Nokulunga; Kunene, Zamantimande; Balakrishna, Yusentha; Albers, Patricia N.; Mathee, Angela

    2017-01-01

    Increased temperatures affect human health and vulnerable groups including infants, children, the elderly and people with pre-existing diseases. In the southern African region climate models predict increases in ambient temperature twice that of the global average temperature increase. Poor ventilation and lack of air conditioning in primary health care clinics, where duration of waiting time may be as long as several hours, pose a possible threat to patients seeking primary health care. Drawing on information measured by temperature loggers installed in eight clinics in Giyani, Limpopo Province of South Africa, we were able to determine indoor temperatures of waiting rooms in eight rural primary health care facilities. Mean monthly temperature measurements inside the clinics were warmer during the summer months of December, January and February, and cooler during the autumn months of March, April and May. The highest mean monthly temperature of 31.4 ± 2.7 °C was recorded in one clinic during February 2016. Maximum daily indoor clinic temperatures exceeded 38 °C in some clinics. Indoor temperatures were compared to ambient (outdoor) temperatures and the mean difference between the two showed clinic waiting room temperatures were higher by 2–4 °C on average. Apparent temperature (AT) incorporating relative humidity readings made in the clinics showed ‘realfeel’ temperatures were >4 °C higher than measured indoor temperature, suggesting a feeling of ‘stuffiness’ and discomfort may have been experienced in the waiting room areas. During typical clinic operational hours of 8h00 to 16h00, mean ATs fell into temperature ranges associated with heat–health impact warning categories of ‘caution’ and ‘extreme caution’. PMID:28067816

  9. Dependence of leaf surface potential response of a plant (Ficus Elastica) to light irradiation on room temperature; Shokubutsu (gomunoki) hamen den`i no hikari shosha oto no shitsuon izonsei

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, H.; Kenmoku, Y.; Sakakibara, T. [Toyohashi University of Technology, Aichi (Japan); Nakagawa, S. [Maizuru National College of Technology, Kyoto (Japan); Kawamoto, T. [Shizuoka University, Shizuoka (Japan)

    1997-11-25

    In order to clarify plant body potential information, study was made on a leaf surface potential response to light irradiation. The leaf surface potential change, total transpiration and transpiration rate of Ficus Elastica were measured using light irradiation period and room temperature as parameters. The leaf surface potential change shows a positive peak after the start of light irradiation, while a negative peak after its end. Arrival time to both peaks is constant regardless of the light irradiation period, while decrease with an increase in room temperature. Although the total transpiration increases with room temperature, this tendency disappears with an increase in light irradiation period. The transpiration rate shows its peak after the start of light irradiation. Arrival time to the peak is saturated with the light irradiation period of 60min, while decreases with an increase in room temperature. These results suggest that opening of stomata becomes active with an increase in room temperature, and the peak of the leaf surface potential after the start of light irradiation relates to the opening. 3 refs., 11 figs.

  10. Effects of multiple concurrent stressors on rectal temperature, blood acid-base status, and longissimus muscle glycolytic potential in market-weight pigs.

    Science.gov (United States)

    Ritter, M J; Ellis, M; Anderson, D B; Curtis, S E; Keffaber, K K; Killefer, J; McKeith, F K; Murphy, C M; Peterson, B A

    2009-01-01

    Sixty-four market-weight (130.0 +/- 0.65 kg) barrows (n = 16) and gilts (n = 48) were used in a split-plot design with a 2 x 2 x 2 factorial arrangement of treatments: 1) handling intensity (gentle vs. aggressive), 2) transport floor space (0.39 vs. 0.49 m(2)/pig), and 3) distance moved during handling (25 vs. 125 m) to determine the effects of multiple concurrent stressors on metabolic responses. For the handling intensity treatment, pigs were moved individually approximately 50 m through a handling course with either 0 (gentle) or 8 (aggressive) shocks from an electric goad. Pigs were loaded onto a trailer and transported for approximately 1 h at floor spaces of either 0.39 or 0.49 m(2)/pig. After transport, pigs were unloaded, and the distance moved treatment was applied; pigs were moved 25 or 125 m through a handling course using livestock paddles. Rectal temperature was measured, and blood samples (to measure blood acid-base status) were collected 2 h before the handling intensity treatment was applied and immediately after the distance moved treatment was applied. A LM sample to measure glycolytic potential was collected after the distance moved treatments on a subset of 32 pigs. There were handling intensity x distance moved interactions (P blood acid-base measurements. In general, there was no effect of distance moved on these traits when pigs were previously handled gently. However, when pigs were previously handled aggressively, pigs moved 125 compared with 25 m had greater (P blood lactate and less (P blood pH, bicarbonate, and base-excess. Pigs transported at 0.39 compared with 0.49 m(2)/pig had a greater (P floor space did not affect any other measurements. Data were analyzed by the number of stressors (the aggressive handling, restricted transport floor space, and 125-m distance moved treatments) experienced by each pig (0, 1, 2, or 3). As the number of stressors experienced by the pig increased, rectal temperature, blood lactate, and LM lactate

  11. Long-term Trend of Cold Air Mass Amount below a Designated Potential Temperature in Northern and Southern Hemisphere Winters with 7 Different Reanalysis Datasets

    Science.gov (United States)

    Kanno, Y.; Abdillah, M. R.; Iwasaki, T.

    2015-12-01

    This study addresses that the hemispheric total cold air mass amount defined below a threshold potential temperature of 280 K is a good indicator of the long-term trend of climate change in the polar region. We demonstrate quantitative analyses of warming trend in the Northern Hemisphere (NH) and Southern Hemisphere (SH) winters, using 7 different reanalysis datasets (JRA-55, JRA-55C, JRA-55AMIP, ERA-interim, CFSR, JRA-25, NCEP-NCAR). Hemispheric total cold air mass amount in the NH winter exhibit a statistically significant decreasing trend in all reanalysis datasets at a rate about -1.37 to -0.77% per decade over the period 1959-2012 and at a rate about -1.57 to -0.82% per decade over 1980-2012. There is no statistically significant trend in the equatorward cold air mass flux across latitude of 45N, which is an indicator for hemispheric-scale cold air outbreak, over the period 1980-2012 except for NCEP-NCAR reanalysis dataset which shows substantial decreasing trend of about -3.28% per decade. The spatial distribution of the long-term trend of cold air mass amount in the NH winter is almost consistent among reanalysis datasets except for JRA-55AMIP over the period 1980-2012. Cold air mass amount increases over Central Siberia, Kamchatka peninsula, and Bering Sea, while it decreases over Norwegian Sea, Barents Sea, Kara Sea, Greenland, Canada, Northern part of United States, and East Asia. In the SH winter, on the other hand, there is a large discrepancy in hemispheric total cold air mass amount and equatorward cold air mass flux across latitude of 50S over the period 1980-2010 among reanalysis datasets. This result indicate that there is a large uncertainty in the long-term trend of cold air mass amount in the SH winter.

  12. High temperature and risk of hospitalizations, and effect modifying potential of socio-economic conditions: A multi-province study in the tropical Mekong Delta Region.

    Science.gov (United States)

    Phung, Dung; Guo, Yuming; Nguyen, Huong T L; Rutherford, Shannon; Baum, Scott; Chu, Cordia

    2016-01-01

    The Mekong Delta Region (MDR) in Vietnam is highly vulnerable to extreme weather related to climate change. However there have been hardly any studies on temperature-hospitalization relationships. The objectives of this study were to examine temperature-hospitalization relationship and to evaluate the effects of socio-economic factors on the risk of hospitalizations due to high temperature in the MDR. The Generalized Linear and Distributed Lag Models were used to examine hospitalizations for extreme temperature for each of the 13 provinces in the MDR. A random-effects meta-analysis was used to estimate the pooled risk for all causes, and for infectious, cardiovascular, and respiratory diseases sorted by sex and age groups. Random-effects meta-regression was used to evaluate the effect of socio-economic factors on the temperature-hospitalization association. For 1°C increase in average temperature, the risk of hospital admissions increased by 1.3% (95% CI, 0.9-1.8) for all causes, 2.2% (95% CI, 1.4-3.1) for infectious diseases, and 1.1% (95% CI, 0.5-1.7) for respiratory diseases. However the result was inconsistent for cardiovascular diseases. Meta-regression showed population density, poverty rate, and illiteracy rate increased the risk of hospitalization due to high temperature, while higher household income, houses using safe water, and houses using hygienic toilets reduced this risk. In the MDR, high temperatures have a significant impact on hospitalizations for infectious and respiratory diseases. Our findings have important implications for better understanding the future impacts of climate change on residents of the MDR. Adaptation programs that consider the risk and protective factors should be developed to protect residents from extreme temperature conditions.

  13. New insights on pressure, temperature, and chemical stability of CsAlSi5O12, a potential host for nuclear waste

    Science.gov (United States)

    Gatta, G. D.; Brundu, A.; Cappelletti, P.; Cerri, G.; de'Gennaro, B.; Farina, M.; Fumagalli, P.; Guaschino, L.; Lotti, P.; Mercurio, M.

    2016-10-01

    A Cs-bearing polyphase aggregate with composition (in wt%): 76(1)CsAlSi5O12 + 7(1)CsAlSi2O6 + 17(1)amorphous, was obtained from a clinoptilolite-rich epiclastic rock after a beneficiation process of the starting material (aimed to increase the fraction of zeolite to 90 wt%), cation exchange and then thermal treatment. CsAlSi5O12 is an open-framework compound with CAS topology; CsAlSi2O6 is a pollucite-like material with ANA topology. The thermal stability of this polyphase material was investigated by in situ high- T X-ray powder diffraction, the combined P- T effects by a series of runs with a single-stage piston cylinder apparatus, and its chemical stability following the "availability test" ("AVA test") protocol. A series of additional investigations were performed by WDS-electron microprobe analysis in order to describe the P- T-induced modification of the material texture, and to chemically characterize the starting material and the run products. The "AVA tests" of the polyphase aggregate show an extremely modest release of Cs+: 0.05 mg/g. In response to applied temperature and at room P, CsAlSi5O12 experiences an unquenchable and displacive Ama2-to- Amam phase transition at about 770 K, and the Amam polymorph is stable in its crystalline form up to 1600 K; a crystalline-to-amorphous phase transition occurs between 1600 and 1650 K. In response to the applied P = 0.5 GPa, the crystalline-to-amorphous transition of CsAlSi5O12 occurs between 1670 and 1770 K. This leads to a positive Clapeyron slope (i.e., d P/d T > 0) of the crystalline-to-amorphous transition. When the polyphase aggregate is subjected at P = 0.5 GPa and T > 1770 K, CsAlSi5O12 melts and only CsAlSi2O6 (pollucite-like; dominant) and Cs-rich glass (subordinate) are observed in the quenched sample. Based on its thermo-elastic behavior, P- T phase stability fields, and Cs+ retention capacity, CsAlSi5O12 is a possible candidate for use in the immobilization of radioactive isotopes of Cs, or as

  14. New insights on pressure, temperature, and chemical stability of CsAlSi5O12, a potential host for nuclear waste

    Science.gov (United States)

    Gatta, G. D.; Brundu, A.; Cappelletti, P.; Cerri, G.; de'Gennaro, B.; Farina, M.; Fumagalli, P.; Guaschino, L.; Lotti, P.; Mercurio, M.

    2016-06-01

    A Cs-bearing polyphase aggregate with composition (in wt%): 76(1)CsAlSi5O12 + 7(1)CsAlSi2O6 + 17(1)amorphous, was obtained from a clinoptilolite-rich epiclastic rock after a beneficiation process of the starting material (aimed to increase the fraction of zeolite to 90 wt%), cation exchange and then thermal treatment. CsAlSi5O12 is an open-framework compound with CAS topology; CsAlSi2O6 is a pollucite-like material with ANA topology. The thermal stability of this polyphase material was investigated by in situ high-T X-ray powder diffraction, the combined P-T effects by a series of runs with a single-stage piston cylinder apparatus, and its chemical stability following the "availability test" ("AVA test") protocol. A series of additional investigations were performed by WDS-electron microprobe analysis in order to describe the P-T-induced modification of the material texture, and to chemically characterize the starting material and the run products. The "AVA tests" of the polyphase aggregate show an extremely modest release of Cs+: 0.05 mg/g. In response to applied temperature and at room P, CsAlSi5O12 experiences an unquenchable and displacive Ama2-to-Amam phase transition at about 770 K, and the Amam polymorph is stable in its crystalline form up to 1600 K; a crystalline-to-amorphous phase transition occurs between 1600 and 1650 K. In response to the applied P = 0.5 GPa, the crystalline-to-amorphous transition of CsAlSi5O12 occurs between 1670 and 1770 K. This leads to a positive Clapeyron slope (i.e., dP/dT > 0) of the crystalline-to-amorphous transition. When the polyphase aggregate is subjected at P = 0.5 GPa and T > 1770 K, CsAlSi5O12 melts and only CsAlSi2O6 (pollucite-like; dominant) and Cs-rich glass (subordinate) are observed in the quenched sample. Based on its thermo-elastic behavior, P-T phase stability fields, and Cs+ retention capacity, CsAlSi5O12 is a possible candidate for use in the immobilization of radioactive isotopes of Cs, or as potential

  15. The potential information in the temperature difference be-tween shadow and sunlit of surfaces and a new way of retrieving the soil moisture

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The thermal inertia and plant water stress index are oftenadopted to estimate soil moisture available for crops or plants. However, it is not very easy to obtain two temporal temperatures for thermal inertia model and air temperature for the plant water stress mode. Shadows of ground objects are often referred to noise on visible and near infrared remote sensing. But the difference of temperature between shadows and sunlit contains rich information concerning with heat-water status for soil. This paper presented a new way to excavate just by temperature difference usually between shadow and sunlit surface. Experiments validated the ideal. We can adopt thermal camera to measure the differences in the field measurements. However, we must use inversion based on multianglar thermal infrared remote sensing data in airborne and spaceborne. An inverting model was also presented by using Monte-Carlo and the least square method. Results show that this way is feasible.

  16. The dual temperature/pH-sensitive multiphase behavior of poly(N-isopropylacrylamide-co-acrylic acid) microgels for potential application in in situ gelling system.

    Science.gov (United States)

    Xiong, Wei; Gao, Xiang; Zhao, Yanbing; Xu, Huibi; Yang, Xiangliang

    2011-05-01

    Poly(N-isopropylacrylamide-co-acrylic acid) microgels (PNA) may be an excellent formulation for in situ gelling system due to their high sensitivity and fast response rate. Four monodispersed PNA microgels with various contents of acrylic acid (AA) were synthesized by emulsion polymerization in this paper. Their hydrodynamic diameters decreased reversibly with both decreasing pH and increasing temperature. The dual temperature/pH-sensitivity was influenced by many factors such as AA content, cross-link density and ion strength. In addition, high concentration PNA dispersions underwent multiple phase transition according to different temperatures, pHs and concentrations, which were summarized in a 3D sol-gel phase diagram in this study. According to the sol-gel phase transition, 8% PNA-025 dispersion maintained a relatively low viscosity and favorable fluidity at pH 5.0 in the temperature range of 25-40°C, but it rapidly increased in viscosity at pH 7.4 and gelled at 37°C. This feature enabled the dual temperature/pH-sensitive microgels to overcome the troubles in syringing of temperature sensitive materials during the injection. Apart from this, PNA could form gel well in in vitro (e.g., medium and serum) and in in vivo with low cytotoxicity. Therefore, it is promising for PNA to be applied in the in situ gelling system.

  17. [New potentials for monitoring the temperature and the relative and absolute humidity of the air-oxygen mixture during the prolonged artificial ventilation of newborn infants].

    Science.gov (United States)

    Milenin, O B; Efimov, M S

    1998-01-01

    A new HTM-902 monitor (UCCP, Germany/Serviceinstrument, Russia) was used for continuous measurements of the temperature and relative and absolute humidity of inspired gas during prolonged mechanical ventilation in 86 neonates with respiratory failure caused by the respiratory distress syndrome (n = 42), meconium aspiration syndrome (n = 28), and congenital pneumonia (n = 16). All measurements were performed with a special probe connected to the inspiratory contour through a standard adapter close to the patient's T-piece. The monitor helped maintain the optimal values of the inspired gas conditioning during assisted ventilation of the neonates. The optimal relationships between gas temperature and humidity can be attained only with humidifiers with a servocontrol of temperature and heated wire inside the inspiratory circle tube. For maintaining adequate humidity of inspired gas after any changes in the ventilator flow rate or in the temperature inside the incubator, the heating power of the humidifier had to be corrected. However, even with servocontrolled humidifiers and humidity regulation, an increase of temperature inside the incubator over 35 degrees C made impossible the maintenance of the inspired gas humidity at the level of 96-100% with its temperature at the level of the patient's T-piece no higher than 37 degrees C.

  18. Light-dependent changes in the chick pineal temperature and the expression of cHsp90 alpha gene: a potential contribution of in vivo temperature change to the photic-entrainment of the chick pineal circadian clock.

    Science.gov (United States)

    Doi, Masao; Nakajima, Yoshito; Okano, Toshiyuki; Fukada, Yoshitaka

    2002-06-01

    The circadian clock is entrained to the diurnal alteration of environmental conditions such as light and temperature, but the molecular mechanism underlying the entrainment is not fully understood. In the present study, we employed a differential display-based screening for a set of genes that are induced by light in the chick pineal gland, a structure of the central clock entrainable to both light and temperature changes. We found that the level of the mRNA encoding chicken heat shock protein 90 alpha (cHSP90 alpha) was rapidly elevated in the pineal gland within a 5-min exposure of chicks to light. Furthermore, the pineal cHsp90 alpha mRNA was expressed rhythmically under both 12-hr light/12-hr dark (LD) cycles and constant dark (DD) conditions. The total amount of the pineal cHSP90 alpha protein was, however, kept at nearly constant levels under LD cycles, and immunohistochemical analyses of the pineal cHSP90 alpha showed invariable localization at the cytoplasm throughout the day. In vivo measurement of the chick pineal temperature demonstrated its light-dependent and time-of-day-dependent change, and the profile was very similar to that of the pineal cHSP90 alpha mRNA level. These observations suggest that the in vivo temperature change regulates the expression of temperature-responsive genes including cHSP 90 alpha in the pineal gland. The temperature change may induce a phase-shift of the pineal clock, thereby facilitating its efficient entrainment to environmental LD cycles.

  19. The 2PI finite temperature effective potential of the O(N) linear sigma model in 1+1 dimensions, at next-to-leading order in 1/N

    CERN Document Server

    Baacke, J; Baacke, Jurgen; Michalski, Stefan

    2004-01-01

    We study the O(N) linear sigma model in 1+1 dimensions. We use the 2PI formalism of Cornwall, Jackiw and Tomboulis in order to evaluate the effective potential at finite temperature. At next-to-leading order in a 1/N expansion one has to include the sums over "necklace" and generalized "sunset" diagrams. We find that - in contrast to the Hartree approximation - there is no spontaneous symmetry breaking in this approximation, as to be expected for the exact theory. The effective potential becomes convex throughout for all parameter sets which include N=4 and N=10, couplings lambda=0.1 and 0.5 and temperatures between 0.2 and 1. The Green's functions obtained by solving the Schwinger-Dyson equations are enhanced in the infrared region. We also compare the effective potential as function of the external field phi with those obtained in various other approximations.

  20. Engineering of Highly Susceptible Paramagnetic Nanostructures of Gd2S3:Eu3+: Potentially an Efficient Material for Room Temperature Gas Sensing Applications

    Directory of Open Access Journals (Sweden)

    Muhammed M. Radhi

    2010-11-01

    Full Text Available This research papers throws light into the compositional, morphological and structural properties of novel nanoparticles of Gd2S3:Eu3+ synthesized by a simple co-precipitation technique. Furthermore, we also prognosticate that this material could be useful for gas sensing applications at room temperature. Nanostructures formulation by this method resulted in the formation of orthorhombic crystal structure with primitive lattice having space group Pnma. The material characterizations are performed using X-ray diffraction (XRD, energy dispersive X-ray analysis (EDX, thermo-gravimetric analysis/differential thermal analysis (TGA/DTA and transmission electron microscope (TEM. The calculated crystallite sizes are ~ 2-5 nm and are in well accordance with the HRTEM results. EDX result confirms the presence and homogeneous distribution of Gd and Eu throughout the nanoparticle. The prepared nanoparticles exhibit strong paramagnetic nature with paramagnetic term, susceptibility c = 8.2 ´ 10-5 emg/g Gauss. TGA/DTA analysis shows 27 % weight loss with rise in temperature. The gas sensing capability of the prepared Gd2S3:Eu3+ magnetic nanoparticles are investigated using the amperometric method. These nanoparticles show good I-V characteristics with ideal semiconducting nature at room temperature with and without ammonia dose. The observed room temperature sensitivity with increasing dose of ammonia indicates applicability of Gd2S3 nanoparticles as room temperature ammonia sensors.

  1. Synthesis of a Temperature-Sensitive Matrine-Imprinted Polymer and Its Potential Application for the Selective Extraction of Matrine from Radix Sophorae Tonkinensis

    Directory of Open Access Journals (Sweden)

    Minjie Jiang

    2015-02-01

    Full Text Available A temperature-sensitive matrine-imprinted polymer was prepared in chloroform by free-radical cross-linking copolymerization of methacrylic acid at 60 °C in the presence of ethylene glycol dimethacrylate as the cross-linker, N-isopropyl acrylamide as the temperature-responsive monomer and matrine as the template molecule. Binding experiments and Scatchard analyses revealed that two classes of binding sites were formed on molecular imprinted polymer (MIP at 50 °C. Additionally, the thermoresponsive MIP was tested for its application as a sorbent material for the selective separation of matrine from Chinese medicinal plant radix Sophorae tonkinensis. It was shown that the thermoresponsive MIP displayed different efficiency in clean-up and enrichments using the SPE protocol at different temperatures.

  2. Investigation of the 1D symmetrical linear graded superconductor-dielectric photonic crystals and its potential applications as an optimized low temperature sensors

    Science.gov (United States)

    Baraket, Zina; Zaghdoudi, Jihene; Kanzari, Mounir

    2017-02-01

    Based on the Transfer Matrix Method (TMM) and the two fluid model for a superconductor and by taking account of the thermal expansion effect and thermo optical effects, we theoretically investigates the transmittance spectra of a one dimensional superconductor -dielectric photonic crystal (PC) designed as ((HLS)5/(SLH)5) made up of a BiGeO12(H), SiO2(L) and YaBO2CuO7 (S). The transmittance spectra shows that the system realizes a tunable filter which depends on a nonlinear relation with temperature. It's found that the symmetrical application of a linear deformation d(m) = d0+(m-1).δd(m) where d0 is the initial thickness of the layer m, δd(m) is the elementary added thickness at each layer. This linear gradation of the thickness permits to improve the temperature sensitivity of the system which acts as an optimized low temperature sensor.

  3. Synthesis of a temperature-sensitive matrine-imprinted polymer and its potential application for the selective extraction of matrine from radix Sophorae tonkinensis.

    Science.gov (United States)

    Jiang, Minjie; Wang, Lisheng; Liu, Xu; Yang, Hua; Ren, Fan; Gan, Lizhen; Jiang, Weizhe

    2015-02-04

    A temperature-sensitive matrine-imprinted polymer was prepared in chloroform by free-radical cross-linking copolymerization of methacrylic acid at 60 °C in the presence of ethylene glycol dimethacrylate as the cross-linker, N-isopropyl acrylamide as the temperature-responsive monomer and matrine as the template molecule. Binding experiments and Scatchard analyses revealed that two classes of binding sites were formed on molecular imprinted polymer (MIP) at 50 °C. Additionally, the thermoresponsive MIP was tested for its application as a sorbent material for the selective separation of matrine from Chinese medicinal plant radix Sophorae tonkinensis. It was shown that the thermoresponsive MIP displayed different efficiency in clean-up and enrichments using the SPE protocol at different temperatures.

  4. Transition metal carbides (WC, Mo2C, TaC, NbC) as potential electrocatalysts for the hydrogen evolution reaction (HER) at medium temperatures

    DEFF Research Database (Denmark)

    Meyer, Simon; Nikiforov, Aleksey V.; Petrushina, Irina M.

    2015-01-01

    at medium temperatures (200-400 degrees C). By introducing a new setup which makes use of molten KH2PO4 as electrolyte, a model system for solid acid membrane electrolyser cells was obtained. Metal carbide coated wires prepared by a two-step oxidation carburization reaction of the metal wire surfaces were...

  5. Biocontrol Potential of Lariophagus distinguendus (Hymenoptera: Pteromalidae) Against Sitophilus granarius (Coleoptera: Curculionidae) at Low Temperatures: Reproduction and Parasitoid-Induced Mortality

    DEFF Research Database (Denmark)

    Hansen, Lise Stengård

    2007-01-01

    , it amounted to 70% of the total mortality exerted by the parasitoid; at 18 and 16°C, it was 57 and 42% of the total, respectively. L. distinguendus is a promising biocontrol agent for grain stores in temperate regions because it is able to develop and reproduce at temperatures down to 16°C; its development...

  6. Survey of Properties of Key Single and Mixture Halide Salts for Potential Application as High Temperature Heat Transfer Fluids for Concentrated Solar Thermal Power Systems

    Directory of Open Access Journals (Sweden)

    Chao-Jen Li

    2014-04-01

    Full Text Available In order to obtain high energy efficiency in a concentrated solar thermal power plant, more and more high concentration ratio to solar radiation are applied to collect high temperature thermal energy in modern solar power technologies. This incurs the need of a heat transfer fluid being able to work at more and more high temperatures to carry the heat from solar concentrators to a power plant. To develop the third generation heat transfer fluids targeting at a high working temperature at least 800 ℃, a research team from University of Arizona, Georgia Institute of Technology, and Arizona State University proposed to use eutectic halide salts mixtures in order to obtain the desired properties of low melting point, low vapor pressure, great stability at temperatures at least 800 ℃, low corrosion, and favorable thermal and transport properties. In this paper, a survey of the available thermal and transport properties of single and eutectic mixture of several key halide salts is conducted, providing information of great significance to researchers for heat transfer fluid development.

  7. Twentieth century temperature trends in CMIP3, CMIP5, and CESM-LE climate simulations: Spatial-temporal uncertainties, differences, and their potential sources

    Science.gov (United States)

    Kumar, Sanjiv; Kinter, James L.; Pan, Zaitao; Sheffield, Justin

    2016-08-01

    The twentieth century climate simulations from the Coupled Model Intercomparison Project Phase 3 (CMIP3) and Phase 5 (CMIP5) are compared to assess the models' ability to capture observed near-surface air temperature trends at global, continental, and regional scales. We computed trends by using a nonparametric method and considering long-term persistence in the time series. The role of internal variability is examined by using large ensemble climate simulations from the National Center for Atmospheric Research model Community Earth System Model (CESM). We computed temperature trends for three periods: the twentieth century, the second half of the twentieth century, and (3) the recent hiatus period to contrast the roles of external forcing and internal variability at various spatial and temporal scales. Both CMIP ensembles show statistically significant warming at global and continental scales during the twentieth century. We found a small but statistically significant difference between CMIP3 (0.57 ± 0.07 °C/century) and CMIP5 (0.47 ± 0.06 °C/century) twentieth century temperature trends, with the CMIP3 estimate being closer to the observations. The spatial structure of long-term temperature trends, and top-of-the atmosphere net radiation trends, suggests that differences in model parameterizations and feedback processes that lead to a smaller net radiative forcing are likely contributing to the differences between CMIP3 and CMIP5. The estimate of internal variability based on the CESM large ensemble spans 24% of the uncertainty in CMIP5 for the twentieth century temperature trends, and 76% for the recent hiatus period, both at global scales, and 43% and almost 100% during the corresponding time periods at regional scales.

  8. The geographical distribution of the potential for seed germination and seedling establishment of Pinus densiflora in Japan as influenced by soil and air temperatures

    Science.gov (United States)

    Kashiwagi, Y.

    1991-12-01

    The geographical distribution of Pinus densiflora forests in Japan was examined in relation to the seed germination and seedling establishment information obtained from laboratory experiments, field observations and field experiments. The laboratory experiments indicated that seed germination can occur in all areas of Japan because effective cumulative soil temperatures reaches to 75 °C · day everywhere. However, the field observations and field experiments suggested that seedling establishment is impossible in the northern, eastern and central parts of Hokkaido because the effective cumulative air temperature at a height of 6 cm over bare ground is less than 2 000 °C · day. These results agree approximately with the actual geographical distribution of P. densiflora forest, which can not be found under natural circumstances in these areas.

  9. The effects of post-treatments and temperature on recovering the methane potential of > 2 mm solid fraction of digested cow manure

    DEFF Research Database (Denmark)

    Kaparaju, Prasad Laxmi-Narasimha; Rintala, J.A.

    2005-01-01

    batch assays at 5-20 degrees C and at 35-55 degrees C to evaluate the treatment effects both under long-term (340 d) storage of solids and during active digestion (30 d), respectively. The effects of different treatments on the methane production of the solids varied with incubation temperatures...... and time. However, in all cases, methane productions at 15 degrees C and lower were slow and low for both untreated and treated solids even after long-term incubation. At 35 and 55 degrees C more methane was recovered from untreated solids producing up to 61-82 ml g(-1) volatile solids (VS)(added) in 30 d...... and 179-215 ml g(-1) VSadded in 340 d. Only chemical treatment with or without thermal treatment enhanced the methane yields while some treatments even decreased the yields. An increase in temperature to 35 degrees C of the assays incubated for 6 months at...

  10. Temperature dependent magnetic properties and application potential of intermetallic Fe{sub 11-x}Co{sub x} TiCe

    Energy Technology Data Exchange (ETDEWEB)

    Goll, D.; Loeffler, R.; Stein, R.; Pflanz, U.; Goeb, S.; Karimi, R.; Schneider, G. [Aalen University, Materials Research Institute (Germany)

    2014-10-15

    The novel quaternary compound Fe{sub 11-x}Co{sub x} TiCe (x = 0 to 3.25) of Mn{sub 12}Th structure has been fabricated by arc melting. The analysis is focused on temperature dependent determination of intrinsic properties from 4 K to 750 K using domain pattern analysis and magnetometry. Above room temperature RT maximum values of anisotropy constant K{sub 1} and saturation polarization J{sub s} are observed for a Co content of 15 at% (x = 1.95) with K{sub 1} and J{sub s} of 2.15 MJ/m{sup 3} (1.22 MJ/m{sup 3}) and 1.27 T (1.05 T) at RT (200 C). At operating temperatures of 100 C for this material magnetic properties (BH){sub max}= 282 kJ/m{sup 3}, μ{sub 0}H{sub c} = 0.94 T are expected. If a suitable microstructure could be processed, based on intrinsic properties of the phases the costs would be 35% per J/m{sup 3} of the costs of Dy-free Fe-Nd-B. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Characterization and potential of three temperature ranges for hydrogen fermentation of cellulose by means of activity test and 16s rRNA sequence analysis.

    Science.gov (United States)

    Gadow, Samir I; Jiang, Hongyu; Li, Yu-You

    2016-06-01

    A series of standardized activity experiments were performed to characterize three different temperature ranges of hydrogen fermentation from different carbon sources. 16S rRNA sequences analysis showed that the bacteria were close to Enterobacter genus in the mesophilic mixed culture (MMC) and Thermoanaerobacterium genus in the thermophilic and hyper-thermophilic mixed cultures (TMC and HMC). The MMC was able to utilize the glucose and cellulose to produce methane gas within a temperature range between 25 and 45 °C and hydrogen gas from 35 to 60°C. While, the TMC and HMC produced only hydrogen gas at all temperature ranges and the highest activity of 521.4mlH2/gVSSd was obtained by TMC. The thermodynamic analysis showed that more energy is consumed by hydrogen production from cellulose than from glucose. The experimental results could help to improve the economic feasibility of cellulosic biomass energy using three-phase technology to produce hythane.

  12. A hybrid geothermal energy conversion technology: Auxiliary heating of geothermally preheated water or CO2 - a potential solution for low-temperature resources

    Science.gov (United States)

    Saar, Martin; Garapati, Nagasree; Adams, Benjamin; Randolph, Jimmy; Kuehn, Thomas

    2016-04-01

    Safe, sustainable, and economic development of deep geothermal resources, particularly in less favourable regions, often requires employment of unconventional geothermal energy extraction and utilization methods. Often "unconventional geothermal methods" is synonymously and solely used as meaning enhanced geothermal systems, where the permeability of hot, dry rock with naturally low permeability at greater depths (4-6 km), is enhanced. Here we present an alternative unconventional geothermal energy utilization approach that uses low-temperature regions that are shallower, thereby drastically reducing drilling costs. While not a pure geothermal energy system, this hybrid approach may enable utilization of geothermal energy in many regions worldwide that can otherwise not be used for geothermal electricity generation, thereby increasing the global geothermal resource base. Moreover, in some realizations of this hybrid approach that generate carbon dioxide (CO2), the technology may be combined with carbon dioxide capture and storage (CCS) and CO2-based geothermal energy utilization, resulting in a high-efficiency (hybrid) geothermal power plant with a negative carbon footprint. Typically, low- to moderate-temperature geothermal resources are more effectively used for direct heat energy applications. However, due to high thermal losses during transport, direct use requires that the heat resource is located near the user. Alternatively, we show here that if such a low-temperature geothermal resource is combined with an additional or secondary energy resource, the power production is increased compared to the sum from two separate (geothermal and secondary fuel) power plants (DiPippo et al. 1978) and the thermal losses are minimized because the thermal energy is utilized where it is produced. Since Adams et al. (2015) found that using CO2 as a subsurface working fluid produces more net power than brine at low- to moderate-temperature geothermal resource conditions, we

  13. Molecular dynamics study of force acting on a model nano particle immersed in fluid with temperature gradient: Effect of interaction potential

    Science.gov (United States)

    Tsuji, Tetsuro; Iseki, Hirotaka; Hanasaki, Itsuo; Kawano, Satoyuki

    2016-11-01

    Thermophoresis of a nano particle in a fluid is investigated using molecular dynamics simulation. In order to elucidate effective factors on the characteristics of thermophoresis, simple models for both the fluid and the nano particle are considered, namely, the surrounding fluid consists of Lennard-Jones (LJ) particles and the model nano particle is a cluster consisting of several tens of LJ particles. Interaction between the fluid particle and the model nano particle is described by the LJ interaction potential or repulsive interaction potential with the Lorentz-Berthelot mixing rule. As a preliminary result, the effect of mass on thermophoretic force acting on the model nano particle is investigated for both interaction potentials.

  14. Geothermal potential of northern Bavaria: Analysis of geothermal resources by evaluation of geophysical temperature logs in drinking water wells and deep wells; Geothermisches Potential Nordbayerns - Untersuchungen der geothermischen Verhaeltnisse durch Auswertung geophysikalischer Temperaturmessungen in Trinkwasser- und Tiefbohrungen

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, W.; Udluft, P. [Lehr- und Forschungsbereich Hydrogeologie und Umwelt, Inst. fuer Geologie, Wuerzburg Univ. (Germany)

    1997-12-01

    The geothermal potential of northern Bavaria was investigated. Thermal water in the lower heat range may be used, e.g., for space heating, bath heating and agricultural purposes. Geophysical data were obtained from a number of drinking water wells with a depth of less than 150 m and a few deep wells of more than 150 m. The data are to serve as a decision aid for potential users of geothermal energy and reduce the exploration risk. (orig.) [Deutsch] Zielsetzung des Forschungsvorhabens ist die Bewertung des geothermischen Potentials Nordbayerns im Hinblick auf die Nutzung von Tiefenwasser zur Gewinnung von hydrothermaler Energie. Niedrigthermale Tiefenwaesser bieten sich z.B. als Energietraeger fuer Raumwaerme, Baederheizung and landwirtschaftliche Nutzung an. Die geothermischen Daten liegen in Form von geophysikalischen Temperaturmessungen aus zahlreichen Trinkwasserbohrungen mit weniger als 150 m Bohrtiefe und einigen Tiefbohrungen mit mehr als 150 m Bohrtiefe vor. Die Bewertung des geothermischen Potentials Nordbayerns soll als Planungsgrundlage fuer potentialle Erdwaermenutzer dienen und zu einer Minimierung des Explorationsrisikos beitragen. (orig.)

  15. Significant light and temperature dependent monoterpene emissions from European beech (Fagus sylvatica L.) and their potential impact on the European volatile organic compound budget

    Science.gov (United States)

    Dindorf, T.; Kuhn, U.; Ganzeveld, L.; Schebeske, G.; Ciccioli, P.; Holzke, C.; KöBle, R.; Seufert, G.; Kesselmeier, J.

    2006-08-01

    By using a dynamic branch enclosure system the emission of monoterpenes from European beech (Fagus sylvatica L.) was investigated during two consecutive summer vegetation periods in the years of 2002 and 2003 in Germany. All measurements were performed under field conditions within the framework of the ECHO project (Emission and Chemical Transformation of Biogenic Volatile Organic Compounds, AFO 2000). European beech was characterized as a substantial emitter of monoterpenes, with sabinene being the predominant compound released. The monoterpene emission from European beech was shown to be a function of light and temperature and agreed well to emission algorithms that consider a light and temperature dependent release of volatile organics. Standard emission factors that were measured from these sunlit leaves of European beech ranged up to 4-13 μg g-1 h-1 (normalized to 1000 μmol m-2 s-1, 30°C) in the years of 2003 and 2002, respectively. The nighttime emission of monoterpene compounds was negligible. Also the artificial darkening of the sunlit branch during daylight conditions led to an immediate cessation of monoterpene emission. European beech is the dominating deciduous tree species in Europe. To demonstrate the effect of an updated monoterpene emission factor for European beech in combination with the consideration of a light and temperature dependent monoterpene emission, we applied a species based model simulation on a European scale. With respect to conventional estimates of the European volatile organic compound budget, the latter simulation resulted in relative increases of 16% by taking solely this tree species into account. On local scales these increases exceeded even more than 100% depending on the respective vegetation area coverage of European beech.

  16. The potential information in the temperature difference be-tween shadow and sunlit of surfaces and a new way of retrieving the soil moisture

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Renhua

    2001-01-01

    [1]Zhang Renhua, A new model for estimating crop water deficiency based on infrared information, Science in China, Ser. B, 1987, 30(4): 413[2]Jackson, R. D., Canopy temperature as a crop water stress indictor, Water Resources Research, 1981, 17 (4): 1133.[3]Price, J. C., Thermal inertia mapping: a new view of earth, Journal of Geophysical Research, 1982, 87: 2582.[4]Kahle A. B., A simple thermal model of earth surface by remote sensing, Journal of Geophysical Research, 1977, 82: 1673.[5]Zhang Renhua, A remote sensing thermal inertia model for soil moisture and it application, Chinese Science Bulletin, 1991, 35: 924[6]Zhang Renhua, Tia Guliang, Determination of emissivity of objects at normal temperature, Chinese Science Bulletin, 1981, 25: 447.[7]Zhang Renhua, Sun Xiaomin, Li Zhaoliang et al., Revealing of major factors in the directional thermal radiation of ground object: a new way for improving the precision of directional radiant temperature measuring and data analysis, Science in China, Ser. E, 2000, 43 (supplement): 34.[8]Su Hongbo, Zhang Renhua, Sun Xiaomin, et al., The thermal model for discrete vegetation and its solution on pixel scale using computer graphics, Science in China, Ser. E, 2000, 43 (supplement): 62.[9]Zhang Renhua, Sun Xiaomin, Su Hongbo et al., A remote sensing model of CO2 flux for wheat and studying of regional distribution, Science in China, Series D, 1999, 42: 325[10]Li Xiaowen, Strahler, A., Geometric-optical bidirectional reflectance modeling of discrete crown vegetation canopy effect of crown shape and mutual shadowing, IEEE, Transactions on Geoscience and Remote Sensing, 1992, 30: 276.

  17. A xylanase with broad pH and temperature adaptability from Streptomyces megasporus DSM 41476, and its potential application in brewing industry.

    Science.gov (United States)

    Qiu, Zhenhua; Shi, Pengjun; Luo, Huiying; Bai, Yingguo; Yuan, Tiezheng; Yang, Peilong; Liu, Suchun; Yao, Bin

    2010-05-05

    A xylanase gene, xynAM6, was isolated from the genomic DNA library of Streptomyces megasporus DSM 41476 using colony PCR screening method. The 1440-bp full-length gene encodes a 479-amino acid peptide consisting of a putative signal peptide of 36 residues, a family 10 glycoside hydrolase domain and a family 2 carbohydrate-binding module. The mature peptide of xynAM6 was successfully expressed in Pichia pastoris GS115. The optimal pH and temperature were pH 5.5 and 70°C, respectively. The enzyme showed broad temperature adaptability (>60% of the maximum activity at 50-80°C), had good thermostability at 60°C and 70°C, remained stable at pH 4.0-11.0, and was resistant to most proteases. The Km and Vmax values for oat spelt xylan were 1.68mgml(-1) and 436.76μmolmin(-1)mg(-1), respectively, and 2.33mgml(-1) and 406.93μmolmin(-1)mg(-1) for birchwood xylan, respectively. The hydrolysis products of XYNAM6 were mainly xylose and xylobiose. Addition of XYNAM6 (80U) to the brewery mash significantly reduced the filtration rate and viscosity by 36.33% and 35.51%, respectively. These favorable properties probably make XYNAM6 a good candidate for application in brewing industry. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. The Potential Impact of CO2 and Air Temperature Increases on Krummholz's Transformation into Arborescent Form in the Southern Siberian Mountains

    Science.gov (United States)

    Kharuk, V. I.; Dvinskaya, M. L.; Im, S. T.; Ranson, K. J.

    2011-01-01

    Trees in the southern Siberian Mountains forest-tundra ecotone have considerably increased their radial and apical growth increments during the last few decades. This leads to the widespread vertical transformation of mat and prostrate krummholz forms of larch (Larix sibirica Ledeb) and Siberian pine (Pinus sibirica Du Tour). An analysis of the radial growth increments showed that these transformations began in the mid-1980s. Larch showed a greater resistance to the harsh alpine environment and attained a vertical growth form in areas where Siberian pine is still krummholz. Upper larch treeline is about 10 m higher than Siberian pine treeline. Observed apical and radial growth increment increases were correlated with CO2 concentration (r = 0.83-0.87), summer temperatures (r = 0.55-0.64), and "cold period" (i.e. September-May) air temperatures (r = 0.36-0.37). Positive correlation between growth increments and winter precipitation was attributed to snow cover protection for trees during wintertime.

  19. Laboratory Study on the Potential EOR Use of HPAM/VES Hybrid in High-Temperature and High-Salinity Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Dingwei Zhu

    2013-01-01

    Full Text Available Polymer flooding represents one of the most efficient processes to enhance oil recovery, and partially hydrolyzed polyacrylamide (HPAM is a widely used oil-displacement agent, but its poor thermal stability, salt tolerance, and mechanical degradation impeded its use in high-temperature and high-salinity oil reservoirs. In this work, a novel viscoelastic surfactant, erucyl dimethyl amidobetaine (EDAB, with improved thermal stability and salinity tolerance, was complexed with HPAM to overcome the deficiencies of HPAM. The HPAM/EDAB hybrid samples were studied in comparison with HPAM and EDAB in synthetic brine regarding their rheological behaviors and core flooding experiments under simulated high-temperature and high-salinity oil reservoir conditions (T: 85°C; total dissolved solids: 32,868 mg/L; [Ca2+] + [Mg2+]: 873 mg/L. It was found that the HPAM/EDAB hybrids exhibited much better heat- and salinity-tolerance and long-term thermal stability than HPAM. Core flooding tests showed that the oil recovery factors of HPAM/EDAB hybrids are between those of HPAM and EDAB. These results are attributed to the synergistic effect between HPAM and EDAB in the hybrid.

  20. Effects of Tetraethyl Orthosilicate (TEOS on the Light and Temperature Stability of a Pigment from Beta vulgaris and Its Potential Food Industry Applications

    Directory of Open Access Journals (Sweden)

    Gustavo A. Molina

    2014-11-01

    Full Text Available A novel, simple and inexpensive modification method using TEOS to increase the UV light, pH and temperature stability of a red-beet-pigment extracted from Beta vulgaris has been proposed. The effects on the molecular structure of betalains were studied by FTIR spectroscopy. The presence of betacyanin was verified by UV-Vis spectroscopy and its degradation in modified red-beet-pigment was evaluated and compared to the unmodified red-beet-pigment; performance improvements of 88.33%, 16.84% and 20.90% for UV light, pH and temperature stability were obtained, respectively,. Measurements of reducing sugars, phenol, and antioxidant contents were performed on unmodified and modified red-beet-pigment and losses of close to 21%, 54% and 36%, respectively, were found to be caused by the addition of TEOS. Polar diagrams of color by unmodified and modified red-beet-pigment in models of a beverage and of a yogurt were obtained and the color is preserved, although here is a small loss in the chromaticity parameter of the modified red-beet-pigment.

  1. Monte Carlo and theoretical calculations of the first four perturbation coefficients in the high temperature series expansion of the free energy for discrete and core-softened potential models

    Science.gov (United States)

    Zhou, Shiqi; Solana, J. R.

    2013-06-01

    The first four perturbation coefficients in the expansion of the Helmholtz free energy in power series of the inverse of the reduced temperature for a number of potential models with hard-sphere cores plus core-softened and discontinuous tails are obtained from Monte Carlo simulations. The potential models considered include square-well, double square-well, and square-shoulder plus square-well, with different potential parameters. These simulation data are used to evaluate the performance of a traditional macroscopic compressibility approximation (MCA) for the second order coefficient and a recent coupling parameter series expansion (CPSE) for the first four coefficients. Comprehensive comparison indicates the incapability of the MCA for the second order coefficient in most non-stringent situations, and significance of the CPSE in accurately calculating these four coefficients.

  2. Potential method for gas production: high temperature co-pyrolysis of lignite and sewage sludge with vacuum reactor and long contact time.

    Science.gov (United States)

    Yang, Xiao; Yuan, Chengyong; Xu, Jiao; Zhang, Weijiang

    2015-03-01

    Lignite and sewage sludge were co-pyrolyzed in a vacuum reactor with high temperature (900°C) and long contact time (more than 2h). Beneficial synergetic effect on gas yield was clearly observed. Gas yield of blend fuel was evidently higher than that of both parent fuels. The gas volume yield, gas lower heating value (LHV), fixed carbon conversion and H2/CO ratio were 1.42 Nm(3)/kg(blend fuel), 10.57 MJ/Nm(3), 96.64% and 0.88% respectively, which indicated this new method a feasible one for gas production. It was possible that sewage sludge acted as gasification agents (CO2 and H2O) and catalyst (alkali and alkaline earth metals) provider during co-pyrolysis, promoting CO2-char and H2O-char gasification which, as a result, invited the improvement of gas volume yield, gas lower heating value and fixed carbon conversion.

  3. Analysis of potential migrants from plastic materials in milk by liquid chromatography-mass spectrometry with liquid-liquid extraction and low-temperature purification.

    Science.gov (United States)

    Bodai, Zsolt; Szabó, Bálint Sámuel; Novák, Márton; Hámori, Susanne; Nyiri, Zoltán; Rikker, Tamás; Eke, Zsuzsanna

    2014-10-15

    A simple and fast analytical method was developed for the determination of six UV stabilizers (Cyasorb UV-1164, Tinuvin P, Tinuvin 234, Tinuvin 326, Tinuvin 327, and Tinuvin 1577) and five antioxidants (Irgafos 168, Irganox 1010, Irganox 3114, Irganox 3790, and Irganox 565) in milk. For sample preparation liquid-liquid extraction with low-temperature purification combined with centrifugation was used to remove fats, proteins, and sugars. After the cleanup step, the sample was analyzed with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). External standard and matrix calibrations were tested. External calibration proved to be acceptable for Tinuvin P, Tinuvin 234, Tinuvin 326, Tinuvin 327, Irganox 3114, and Irganox 3790. The method was successfully validated with matrix calibration for all compounds. Method detection limits were between 0.25 and 10 μg/kg. Accuracies ranged from 93 to 109%, and intraday precisions were <13%.

  4. Ultrafine-grained magnesium–lithium alloy processed by high-pressure torsion: Low-temperature superplasticity and potential for hydroforming

    Energy Technology Data Exchange (ETDEWEB)

    Matsunoshita, Hirotaka [Department of Materials Science and Engineering, Faculty of Engineering, Kyushu University, Fukuoka 819-0395 (Japan); Edalati, Kaveh, E-mail: kaveh.edalati@zaiko6.zaiko.kyushu-u.ac.jp [Department of Materials Science and Engineering, Faculty of Engineering, Kyushu University, Fukuoka 819-0395 (Japan); WPI, International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395 (Japan); Furui, Mitsuaki [Graduate School of Science and Engineering for Research, University of Toyama, Toyama 930-8555 (Japan); Horita, Zenji [Department of Materials Science and Engineering, Faculty of Engineering, Kyushu University, Fukuoka 819-0395 (Japan); WPI, International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395 (Japan)

    2015-07-29

    A Mg–Li alloy with 8 wt% Li was processed by severe plastic deformation (SPD) through the process of high-pressure torsion (HPT) to achieve ultrafine grains with an average grain size of ~500 nm. Tensile testing with an initial strain rate of 10{sup −3} s{sup −1} showed that the alloy exhibited superplasticity at a temperature of 323 K or higher. Tensile testing in boiling water confirmed that the specimens were elongated to 350–480% at 373 K under the initial strain rates of 10{sup −3} s{sup −1} to {sup 1}0{sup −2} s{sup −1} with a strain rate sensitivity of ~0.3. The current study suggests that not only superplastic forming but also superplastic hydroforming should be feasible after the grain refinement using the HPT method.

  5. Effects of photoperiod and temperature on reproductive diapause in Ophraella communa (Coleoptera:Chrysomelidae), a potential biocontrol agent against Ambrosia artemisiifolia

    Institute of Scientific and Technical Information of China (English)

    Dao-Hong Zhu; Jing Zhu; Zhao-Pu Peng; Fang-Hao Wan

    2012-01-01

    To investigate the seasonal adaptation strategies of Ophraella communa to new habitats,the effects and regulation mechanisms of photoperiod and temperature on the reproductive diapause in a population collected from Changsha,Hunan were examined.Adults showed obvious reproductive diapause,which was regulated by photoperiod and temperature.At 30℃,there was no adult diapause occurring under either long-day or short-day conditions; at 25℃ the pre-oviposition period was short and fecundity was high in adult females under L:D 16:8 h,whereas under L:D 12:12 h,a few females entered reproductive diapause; at 20℃ under short-day conditions,all female adults entered diapause.The pre-oviposition period was significantly prolonged when the pupae and adults were transferred from long-days to short-days,but the day length influence was not obvious when they were transferred only in the adult stage.However,the fecundity dropped greatly no matter whether the photoperiod shifted to short-days only in the adult stage or whether the shift occurred in both the pupal and adult stage.The fecundity was extremely low when photoperiod shifted from long-days to short-days in both pupal and adult stages.This was an indication that the pupal and adult stages were the photoperiod-sensitive stage for adult reproductive diapause.This was especially true for the photoperiod in the pupal stage,which has a distinctly significant regulative effect on reproductive diapause.Additionally,this article also addresses the reason for different photoperiodic response patterns in reproductive diapause induction between the Changsha strain and the Tsukuba strain (Japan) of O.communa.

  6. COMPUTATIONAL MODELING OF CATHODIC LIMITATIONS ON LOCALIZED CORROSION OF WETTED SS 316L, AT ROOM TEMPERATURE

    Energy Technology Data Exchange (ETDEWEB)

    F. Cui; F.J. Presuel-Moreno; R.G. Kelly

    2005-10-13

    The ability of a SS316L surface wetted with a thin electrolyte layer to serve as an effective cathode for an active localized corrosion site was studied computationally. The dependence of the total net cathodic current, I{sub net}, supplied at the repassivation potential E{sub rp} (of the anodic crevice) on relevant physical parameters including water layer thickness (WL), chloride concentration ([Cl{sup -}]) and length of cathode (Lc) were investigated using a three-level, full factorial design. The effects of kinetic parameters including the exchange current density (i{sub o,c}) and Tafel slope ({beta}{sub c}) of oxygen reduction, the anodic passive current density (i{sub p}) (on the cathodic surface), and E{sub rp} were studied as well using three-level full factorial designs of [Cl{sup -}] and Lc with a fixed WL of 25 {micro}m. The study found that all the three parameters WL, [Cl{sup -}] and Lc as well as the interactions of Lc x WL and Lc x [Cl{sup -}] had significant impact on I{sub net}. A five-factor regression equation was obtained which fits the computation results reasonably well, but demonstrated that interactions are more complicated than can be explained with a simple linear model. Significant effects on I{sub net} were found upon varying either i{sub o,c}, {beta}{sub c}, or E{sub rp}, whereas i{sub p} in the studied range was found to have little impact. It was observed that I{sub net} asymptotically approached maximum values (I{sub max}) when Lc increased to critical minimum values. I{sub max} can be used to determine the stability of coupled localized corrosion and the critical Lc provides important information for experimental design and corrosion protection.

  7. Molecular characterization of the cold- and heat-induced Arabidopsis PXL1 gene and its potential role in transduction pathways under temperature fluctuations.

    Science.gov (United States)

    Jung, Chang Gyo; Hwang, Sun-Goo; Park, Yong Chan; Park, Hyeon Mi; Kim, Dong Sub; Park, Duck Hwan; Jang, Cheol Seong

    2015-03-15

    LRR-RLK (Leucine-Rich Repeat Receptor-Like Kinase) proteins are believed to play essential roles in cell-to-cell communication during various cellular processes including development, hormone perception, and abiotic stress responses. We isolated an LRR-RLK gene previously named Arabidopsis PHLOEM INTERCALATED WITH XYLEM-LIKE 1 (AtPXL1) and examined its expression patterns. AtPXL1 was highly induced by cold and heat stress, but not by drought. The fluorescence signal of 35S::AtPXL1-EGFP was closely localized to the plasma membrane. A yeast two-hybrid and bimolecular fluorescence complementation assay exhibited that AtPXL1 interacts with both proteins, A. thaliana histidine-rich dehydrin1 (AtHIRD1) and A. thaliana light-harvesting protein complex I (AtLHCA1). We found that AtPXL1 possesses autophosphorylation activity and phosphorylates AtHIRD1 and AtLHCA1 in an in vitro assay. Subsequently, we found that the knockout line (atpxl1) showed hypersensitive phenotypes when subjected to cold and heat during the germination stage, while the AtPXL1 overexpressing line as well as wild type plants showed high germination rates compared to the knockout plants. These results provide an insight into the molecular function of AtPXL1 in the regulation of signal transduction pathways under temperature fluctuations.

  8. SrMo0.9Co0.1O3-δ: A potential anode for intermediate-temperature solid-oxide fuel cells (IT-SOFC)

    Science.gov (United States)

    Martínez-Coronado, R.; Alonso, J. A.; Fernández-Díaz, M. T.

    2014-07-01

    SrMo0.9Co0.1O3-δ oxide has been prepared, characterized and tested as anode material in single solid-oxide fuel cells (SOFC), yielding output powers close to 800 mW cm-2 at 850 °C with pure H2 as a fuel. This excellent performance is accounted for the results of an "in-situ" neutron powder diffraction (NPD) experiment, at the working conditions of a SOFC, showing the presence of a sufficiently high oxygen deficiency, with large displacement factors for oxygen atoms that suggest a large lability and mobility, combined with a huge metal-like electronic conductivity, as high as 386 S cm-1 at T = 50 °C. Besides, the oxidation of the perovskite gives rise to a new oxygen deficient scheelite-like phase with formula SrMo0.9Co0.1O4-δ with Mo(VI), which has been studied by NPD and thermal analysis as far as crystal structure and composition are concerned. An adequate thermal expansion coefficient for both (oxidized and reduced) phases, an excellent reversibility upon cycling in oxidizing-reducing atmospheres and a good chemical compatibility with the electrolyte (La0.8Sr0.2Ga0.83Mg0.17O3-δ; LSGM) make this oxide a good candidate for anode in intermediate-temperature SOFC (IT-SOFCs).

  9. Coastal circulation and potential coral-larval dispersal in Maunalua Bay, O'ahu, Hawaii—Measurements of waves, currents, temperature, and salinity, June-September 2010

    Science.gov (United States)

    Presto, M. Katherine; Storlazzi, Curt D.; Logan, Joshua B.; Reiss, Thomas E.; Rosenberger, Kurt J.

    2012-01-01

    This report presents a summary of fieldwork conducted in Maunalua Bay, O'ahu, Hawaii to address coral-larval dispersal and recruitment from June through September, 2010. The objectives of this study were to understand the temporal and spatial variations in currents, waves, tides, temperature, and salinity in Maunalua Bay during the summer coral-spawning season of Montipora capitata. Short-term vessel surveys and satellite-tracked drifters were deployed to measure currents during the June 2010 spawning event and to supplement the longer-term measurements of currents and water-column properties by fixed, bottom-mounted instruments deployed in Maunalua Bay. These data show that currents at the surface and just below the surface where coral larvae are found are often oriented in opposite directions due primarily to tidal and trade-winds forcing as the primary mechanisms of circulation in the bay. These data extend our understanding of coral-larvae dispersal patterns due to tidal and wind-driven currents and may be applicable to larvae of other Hawaiian corals.

  10. Transpiração e temperatura foliar da cana-de-açúcar sob diferentes valores de potencial matricial Transpiration and leaf temperature of sugarcane under different matric potential values

    Directory of Open Access Journals (Sweden)

    Roberto Trentin

    2011-12-01

    Full Text Available O objetivo deste trabalho foi avaliar a variação diurna da transpiração e da temperatura foliar da cana-de-açúcar, cv. RB867515, sob diferentes potenciais matriciais de água no substrato de cultivo e as condições meteorológicas em ambiente protegido. O efeito do estresse hídrico na transpiração e temperatura foliar foi determinado a partir da suspensão da irrigação, quando foram realizadas três campanhas de medições, iniciadas aos 122; 150 e 185 dias após o plantio (DAP até que o potencial matricial de água no substrato (Ψ alcançasse -1.500 kPa, aproximadamente. Sob ausência de estresse hídrico (Ψ>-50 kPa, a transpiração das plantas atingiu o valor máximo entre 10 e 13 h, próximo de 60; 70 e 100 g planta-1 h-1 para 122; 150 e 185 DAP, respectivamente. Sob condições de estresse hídrico severo (ΨThe objective of this study was to evaluate the diurnal behaviour of transpiration and leaf temperature of sugarcane (cv. RB867515 under different water matrix potential in the cultivation substrate and greenhouse meteorological conditions. The water stress effect on transpiration and leaf temperature was determined after irrigation suspension, when three measurement campaigns were initiated at 122; 150 and 185 days after planting (DAP until the matrix water potential in the substrate (Ψ reached -1,500 kPa, approximately. Under the absence of water stress (Ψ>-50 kPa, plant transpiration reached the maximum value between 10:00 AM and 13:00 PM, near to 60; 70 e 100 gplant-1h-1, for 122; 150 and 185 DAP, respectively. Under severe water stress (Ψ<-1,100 kPa, there was daily transpiration reduction of approximately 73%, compared to measurements performed without water stress and under similar meteorological conditions. Under the absence of water stress and overcast sky conditions, the average value of the difference between leaf temperature and air temperature was -2.9 ºC. In contrast, under severe water stress and high

  11. The temperature dependences of the electron-deformation potential phonon interacting system of a quasi two dimensional system under circularly-oscillating fields in CdS, GaN and ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Sug, J. Y. [Kyungpook National University, Daegu (Korea, Republic of); Lee, S. H.; Choi, S. Y. [Donga University, Busan (Korea, Republic of)

    2014-11-15

    We study the optical quantum transition line shapes and the optical quantum transition linewidths in relation to the magnetic-field-dependent properties of an electron-deformation potential phonon interaction system. We consider two systems - one is subject to right circularly oscillating external fields and the other is subject to left circularly-oscillatory external fields. We investigated theoretically the temperature dependence of the quantum optical transition of qusi-2-dimensional Landau splitting ystem in CdS, GaN and ZnO.

  12. Fe atoms trapped on graphene as a potential efficient catalyst for room-temperature complete oxidation of formaldehyde: a first-principles investigation

    KAUST Repository

    Guo, Huimin

    2017-03-24

    We investigated the oxidation of formaldehyde, one of the major indoor air pollutants, into CO2 and H2O over Fe atoms trapped in defects on graphene by first-principles based calculations. These trapped Fe atoms are not only stable to withstand interference from the reaction environments but are also efficient in catalyzing the reactions between coadsorbed O-2 and formaldehyde. The oxidation of formaldehyde starts with the formation of a peroxide-like intermediate and continues by its dissociation into. eta(1)-OCHO coadsorbed with an OH radical. Then, the adsorbed OCHO undergoes conformational changes and hydride transfer, leading to the formation of H2O and CO2. Subsequent adsorption of O2 or formaldehyde facilitates desorption of H2O and a new reaction cycle initiates. The calculated barriers for formation and dissociation of the peroxide-like intermediate are 0.43 and 0.40 eV, respectively, and those for conformation changes and hydride transfer are 0.47 and 0.13 eV, respectively. These relatively low barriers along the reaction path suggest the potential high catalytic performance of trapped Fe atoms for formaldehyde oxidation.

  13. Potential of a simple HPLC-based approach for the identification of the spoilage status of minced beef stored at various temperatures and packaging systems.

    Science.gov (United States)

    Argyri, Anthoula A; Doulgeraki, Agapi I; Blana, Vasiliki A; Panagou, Efstathios Z; Nychas, George-John E

    2011-10-17

    The shelf life of minced beef stored (i) aerobically, (ii) under modified atmosphere packaging (MAP), and (iii) under MAP with oregano essential oil (MAP/OEO) at 0, 5, 10, and 15°C was investigated. The microbial association of meat and the temporal biochemical changes were monitored. Microbiological analyses, including total viable counts (TVC), Pseudomonas spp., Brochothrix thermosphacta, lactic acid bacteria, Enterobacteriaceae, and yeasts/moulds, were undertaken, in parallel with sensory assessment, pH measurement and HPLC analysis of the organic acid profiles. Spectral data collected by HPLC were subjected to statistical analysis, including principal component analysis (PCA) and factorial discriminant analysis (FDA). This revealed qualitative discrimination of the samples based on their spoilage status. Partial least squares regression (PLS-R) was used to evaluate quantitative predictions of TVC, Pseudomonas spp., Br. thermosphacta, lactic acid bacteria, Enterobacteriaceae, and yeasts/moulds. Overall, the HPLC analysis of organic acids, was found to be a potential method to evaluate the spoilage and microbial status of a meat sample regardless of the storage conditions. This could be a very useful tool for monitoring the quality of meat batches during transportation and storage in the meat food chain.

  14. Structure of large nitrate-water clusters at ambient temperatures: simulations with effective fragment potentials and force fields with implications for atmospheric chemistry.

    Science.gov (United States)

    Miller, Yifat; Thomas, Jennie L; Kemp, Daniel D; Finlayson-Pitts, Barbara J; Gordon, Mark S; Tobias, Douglas J; Gerber, R Benny

    2009-11-19

    Structural properties of large NO(3)(-).(H(2)O)(n) (n = 15-500) clusters are studied by Monte Carlo simulations using effective fragment potentials (EFPs) and by classical molecular dynamics simulations using a polarizable empirical force field. The simulation results are analyzed with a focus on the description of hydrogen bonding and solvation in the clusters. In addition, a comparison between the electronic structure based EFP and the classical force field description of the 32 water cluster system is presented. The EFP simulations, which focused on the cases of n = 15 and 32, show an internal, fully solvated structure and a "surface adsorbed" structure for the 32 water cluster at 300 K, with the latter configuration being more probable. The internal solvated structure and the "surface adsorbed" structure differ considerably in their hydrogen bonding coordination numbers. The force field based simulations agree qualitatively with these results, and the local geometry of NO(3)(-) and solvation at the surface-adsorbed site in the force field simulations are similar to those predicted using EFPs. Differences and similarities between the description of hydrogen bonding of the anion in the two approaches are discussed. Extensive classical force field based simulations at 250 K predict that long time scale stability of "internal" NO(3)(-), which is characteristic of extended bulk aqueous interfaces, emerges only for n > 300. Ab initio Møller-Plesset perturbation theory is used to test the geometries of selected surface and interior anions for n = 32, and the results are compared to the EFP and MD simulations. Qualitatively, all approaches agree that surface structures are preferred over the interior structures for clusters of this size. The relatively large aqueous clusters of NO(3)(-) studied here are of comparable size to clusters that lead to new particle formation in air. Nitrate ions on the surface of such clusters may have significantly different photochemistry

  15. Development of Xe and Kr empirical potentials for CeO2, ThO2, UO2 and PuO2, combining DFT with high temperature MD

    Science.gov (United States)

    Cooper, M. W. D.; Kuganathan, N.; Burr, P. A.; Rushton, M. J. D.; Grimes, R. W.; Stanek, C. R.; Andersson, D. A.

    2016-10-01

    The development of embedded atom method (EAM) many-body potentials for actinide oxides and associated mixed oxide (MOX) systems has motivated the development of a complementary parameter set for gas-actinide and gas-oxygen interactions. A comprehensive set of density functional theory (DFT) calculations were used to study Xe and Kr incorporation at a number of sites in CeO2, ThO2, UO2 and PuO2. These structures were used to fit a potential, which was used to generate molecular dynamics (MD) configurations incorporating Xe and Kr at 300 K, 1500 K, 3000 K and 5000 K. Subsequent matching to the forces predicted by DFT for these MD configurations was used to refine the potential set. This fitting approach ensured weighted fitting to configurations that are thermodynamically significant over a broad temperature range, while avoiding computationally expensive DFT-MD calculations. The resultant gas potentials were validated against DFT trapping energies and are suitable for simulating combinations of Xe and Kr in solid solutions of CeO2, ThO2, UO2 and PuO2, providing a powerful tool for the atomistic simulation of conventional nuclear reactor fuel UO2 as well as advanced MOX fuels.

  16. Development of Xe and Kr empirical potentials for CeO2, ThO2, UO2 and PuO2, combining DFT with high temperature MD.

    Science.gov (United States)

    Cooper, M W D; Kuganathan, N; Burr, P A; Rushton, M J D; Grimes, R W; Stanek, C R; Andersson, D A

    2016-10-12

    The development of embedded atom method (EAM) many-body potentials for actinide oxides and associated mixed oxide (MOX) systems has motivated the development of a complementary parameter set for gas-actinide and gas-oxygen interactions. A comprehensive set of density functional theory (DFT) calculations were used to study Xe and Kr incorporation at a number of sites in CeO2, ThO2, UO2 and PuO2. These structures were used to fit a potential, which was used to generate molecular dynamics (MD) configurations incorporating Xe and Kr at 300 K, 1500 K, 3000 K and 5000 K. Subsequent matching to the forces predicted by DFT for these MD configurations was used to refine the potential set. This fitting approach ensured weighted fitting to configurations that are thermodynamically significant over a broad temperature range, while avoiding computationally expensive DFT-MD calculations. The resultant gas potentials were validated against DFT trapping energies and are suitable for simulating combinations of Xe and Kr in solid solutions of CeO2, ThO2, UO2 and PuO2, providing a powerful tool for the atomistic simulation of conventional nuclear reactor fuel UO2 as well as advanced MOX fuels.

  17. Low temperature-pressure batch experiments and field push-pull tests: Assessing potential effects of an unintended CO2 release from CCUS projects on groundwater chemistry

    Science.gov (United States)

    Mickler, P. J.; Yang, C.; Lu, J.; Reedy, R. C.; Scanlon, B. R.

    2012-12-01

    primarily through carbonate dissolution which releases Ca and elements that substitute for Ca in crystal lattices. Silicate weathering releases primarily Si and K at lower rates. Chemical changes with the addition of CO2 may initially mobilize As, Mo, V, Zn, Se and Cd but these elements become immobile in the lowered pH water and sorb onto aquifer minerals. A combined laboratory batch experiment and field push-pull test in fresh water aquifers overlying CCUS projects will best characterize the response of the aquifer to increased pCO2. The long experimental duration of the batch experiments may allow reactions to reach equilibrium however; reaction rates may be artificially high due to increased mineral surface areas. Field based push-pull tests offer a more realistic water rock ratio and test a much larger volume of aquifer material but the test must be shorter in duration because the high pCO2 water is subject to mixing with low pCO2 background water and migration away from the test well with groundwater flow. A comparison of the two methods best characterizes the potential effects on groundwater chemistry

  18. The Effect of Flow Rates on the Localized Corrosion Behavior of 304 Stainless Steel in Ozonated 0.5N NaCl

    Science.gov (United States)

    1991-12-15

    measured and values of breakdown and repassivation potentials were deri- ved from cyclic polarization curves. It was found that the transition from laminar...were measured and values of breakdo%&- and repassivation potentials were derived from cyclic polarization curves. It was "Waind that the transition...after being allowed to stabilize for 4000 seconds. For voltametry experiments, the potential was stepped to -600 mV vs. SCE and subsequently polarized

  19. Mussel shells of Mytilus edulis as bioarchives of the rare earth elements and yttrium distribution in seawater and the potential impact of pH and temperature on the partitioning behaviour

    Directory of Open Access Journals (Sweden)

    A. Ponnurangam

    2015-09-01

    Full Text Available Mussel shells are potential bioarchives of proxies for changes of the physico-chemical conditions in the bivalve's habitat. One such proxy is the distribution of the Rare Earths and Yttrium (REY in seawater, as REY speciation in seawater is sensitive to pH and temperature variations, due to the impact of these parameters on the activity of CO32− in seawater. We present a new protocol for sample preparation and determination of REY concentrations in bivalve shells, that includes sample treatment with NaOCl followed by REY separation and preconcentration. The data obtained was further used to calculate REY partition coefficients between shells of M. edulis and ambient seawater, and acquired results were then used in the investigation of the potential effects of pH and temperature on REY partitioning. Shells of M. edulis mussels from the North Sea show consistent shale-normalized ("SN" REY patterns that increase from the light REY to the middle REY and decrease from the middle REY to the heavy REY. Despite being different to the general seawater REYSN pattern, the shells still display distinct REY features of seawater such as a negative CeSN anomaly and small positive YSN and GdSN anomalies. Apparent partition coefficients for the REY between the shell and seawater (appDREYshell/seawater are low and decrease strongly from the light REY (4.04 for La to the heavy REY (0.34 for Lu. However, assuming that only the free REY3+ are incorporated into the shell, appDREY3+shell/seawater values are higher and rather similar for all REY (102.46 for La; 113.44 for Lu, but show a slight maximum at Tb (199.18. Although the impact of vital effects i.e. REY speciation in a mussel's extrapallial fluid from which the carbonate minerals precipitate, cannot be quantified yet, it appears that M. edulis shells are bioarchives of some REY features of seawater. We modelled the REYSN patterns of a hypothetical mussel shell at pH 8.2 and 7.6 and at temperatures of 25

  20. Mussel shells of Mytilus edulis as bioarchives of the rare earth elements and yttrium distribution in seawater and the potential impact of pH and temperature on the partitioning behaviour

    Science.gov (United States)

    Ponnurangam, A.; Bau, M.; Brenner, M.; Koschinsky, A.

    2015-09-01

    Mussel shells are potential bioarchives of proxies for changes of the physico-chemical conditions in the bivalve's habitat. One such proxy is the distribution of the Rare Earths and Yttrium (REY) in seawater, as REY speciation in seawater is sensitive to pH and temperature variations, due to the impact of these parameters on the activity of CO32- in seawater. We present a new protocol for sample preparation and determination of REY concentrations in bivalve shells, that includes sample treatment with NaOCl followed by REY separation and preconcentration. The data obtained was further used to calculate REY partition coefficients between shells of M. edulis and ambient seawater, and acquired results were then used in the investigation of the potential effects of pH and temperature on REY partitioning. Shells of M. edulis mussels from the North Sea show consistent shale-normalized ("SN") REY patterns that increase from the light REY to the middle REY and decrease from the middle REY to the heavy REY. Despite being different to the general seawater REYSN pattern, the shells still display distinct REY features of seawater such as a negative CeSN anomaly and small positive YSN and GdSN anomalies. Apparent partition coefficients for the REY between the shell and seawater (appDREYshell/seawater) are low and decrease strongly from the light REY (4.04 for La) to the heavy REY (0.34 for Lu). However, assuming that only the free REY3+ are incorporated into the shell, appDREY3+shell/seawater values are higher and rather similar for all REY (102.46 for La; 113.44 for Lu), but show a slight maximum at Tb (199.18). Although the impact of vital effects i.e. REY speciation in a mussel's extrapallial fluid from which the carbonate minerals precipitate, cannot be quantified yet, it appears that M. edulis shells are bioarchives of some REY features of seawater. We modelled the REYSN patterns of a hypothetical mussel shell at pH 8.2 and 7.6 and at temperatures of 25 and 5

  1. Projections of precipitation, air temperature and potential ...

    African Journals Online (AJOL)

    mabouelhaggag

    sectors namely agriculture, water resources, human health ... The population growth triggers the need for additional resources to ... however, reversed at coastal and lake areas. There were thus .... the Equator, Rwanda's high elevation makes the climate .... assumed that the daily rainfall distribution at all rainfall gauges will.

  2. Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

    Institute of Scientific and Technical Information of China (English)

    WANG Zixiao; YU Lei; LIU Zhiyong; SONG Ning

    2015-01-01

    Effect of an organic corrosion inhibitor (OCI) named PCI-2014 added in chloride solution on the critical chlo-ride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chlo-ride solution were investigated. The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution. Within a certain chloride ion concentration range, the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution. Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer. Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

  3. Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

    Institute of Scientific and Technical Information of China (English)

    WANG; Zixiao; YU; Lei; LIU; Zhiyong; SONG; Ning

    2015-01-01

    Effect of an organic corrosion inhibitor(OCI) named PCI-2014 added in chloride solution on the critical chloride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chloride solution were investigated.The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution.Within a certain chloride ion concentration range,the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution.Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer.Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

  4. The impact of water and temperature interactions on lag phase, growth and potential ochratoxin A production by two new species, Aspergillus aculeatinus and A. sclerotiicarbonarius, on a green coffee-based medium.

    Science.gov (United States)

    Akbar, Asya; Magan, Naresh

    2014-10-01

    Two new species of Aspergillus (A. aculeatinus, A. sclerotiicarbonarius) were previously isolated from coffee in Thailand. The objective of this study was to examine the effect of interacting environmental factors of water availability (water activity, aw) and temperature on lag phases prior to growth, growth and potential for ochratoxin A (OTA) production by three strains of each species on a green coffee-based medium for the first time. This showed that overall the growth of the three strains of each species was similar over the 20-37°C and 0.85-0.99 aw ranges. The lag phase prior to growth was coffee-based medium. This information is important as these species are part of the mycobiota of coffee and may influence OTA contamination by other ochratoxigenic species during coffee processing.

  5. Photoluminescence and compositional-structural properties of ion-beam sputter deposited Er-doped TiO{sub 2−x}N{sub x} films: Their potential as a temperature sensor

    Energy Technology Data Exchange (ETDEWEB)

    Scoca, D., E-mail: dlsscoca@ifi.unicamp.br; Morales, M.; Merlo, R.; Alvarez, F. [Instituto de Física Gleb Wataghin, UNICAMP, Campinas, São Paulo (Brazil); Zanatta, A. R. [Instituto de Física de São Carlos, USP, São Carlos, São Paulo (Brazil)

    2015-05-28

    Er-doped TiO{sub 2−x}N{sub x} films were grown by Ar{sup +} ion-beam sputtering a Ti + Er target under different N{sub 2} + O{sub 2} high-purity atmospheres. The compositional-structural properties of the samples were investigated after thermal annealing the films up to 1000 °C under a flow of oxygen. Sample characterization included x-ray photoelectron spectroscopy, grazing incidence x-ray diffraction, Raman scattering, and photoluminescence experiments. According to the experimental data, both composition and atomic structure of the samples were very sensitive to the growth conditions and annealing temperature. In the as-deposited form, the N-rich TiO{sub 2−x}N{sub x} films presented TiN crystallites and no photoluminescence. As the thermal treatments proceed, the films were transformed into TiO{sub 2} and Er{sup 3+}-related light emission were observed in the visible and near-infrared ranges at room-temperature. Whereas the development of TiO{sub 2} occurred due to the insertion-diffusion of oxygen in the films, light emission originated because of optical bandgap widening and/or structural-chemical variations in the vicinity of the Er{sup 3+} ions. Finally, the photoluminescence results in the visible range suggested the potential of the present samples in producing an optically based temperature sensor in the ∼150–500 K range.

  6. Effect of transient receptor potential vanilloid 1 (TRPV1) receptor antagonist compounds SB705498, BCTC and AMG9810 in rat models of thermal hyperalgesia measured with an increasing-temperature water bath.

    Science.gov (United States)

    Tékus, Valéria; Bölcskei, Kata; Kis-Varga, Agnes; Dézsi, László; Szentirmay, Eva; Visegrády, András; Horváth, Csilla; Szolcsányi, János; Petho, Gábor

    2010-09-01

    The transient receptor potential vanilloid 1 (TRPV1) receptor is activated by noxious heat, various endogenous mediators and exogenous irritants. The aim of the present study was to compare three TRPV1 receptor antagonists (SB705498, BCTC and AMG9810) in rat models of heat hyperalgesia. The behavioural noxious heat threshold, defined as the lowest temperature evoking nocifensive reaction, was measured with an increasing-temperature water bath. The effects of TRPV1 receptor antagonists were assessed in thermal hyperalgesia induced by the TRPV1 agonist resiniferatoxin (RTX), mild heat injury (51 degrees C, 20s) or plantar incision in rats. The control heat threshold was 43.2+/-0.4 degrees C. RTX induced an 8-10 degrees C decrease in heat threshold which was dose-dependently inhibited by oral pre-treatment with any of the TRPV1 receptor antagonists with a minimum effective dose of 1mg/kg. The mild heat injury-evoked 7-8 degrees C heat threshold drop was significantly reversed by all three antagonists injected i.p. as post-treatment. The minimum effective doses were as follows: SB705498 10, BCTC 3 and AMG9810 1mg/kg. Plantar incision-induced heat threshold drop (7-8 degrees C) was dose-dependently diminished by an oral post-treatment with any of the antagonists with minimum effective doses of 10, 3 and 3mg/kg, respectively. Assessment of RTX hyperalgesia by measurement of the paw withdrawal latency with a plantar test apparatus yielded 30 mg/kg minimum effective dose for each antagonist. In conclusion, measurement of the noxious heat threshold with the increasing-temperature water bath is suitable to sensitively detect the effects of TRPV1 receptor antagonists in thermal hyperalgesia models.

  7. Study of the potential valorisation of heavy metal contaminated biomass via phytoremediation by fast pyrolysis: Part I. Influence of temperature, biomass species and solid heat carrier on the behaviour of heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    C. Lievens; J. Yperman; J. Vangronsveld; R. Carleer [Hasselt University, Diepenbeek (Belgium). Laboratory of Applied Chemistry

    2008-08-15

    Presently, little or no information of implementing fast pyrolysis for looking into the potential valorisation of heavy metal contaminated biomass is available. Fast pyrolysis of heavy metal contaminated biomass (birch and sunflower), containing high amounts of Cd, Cu, Pb and Zn, resulting from phytoremediation, is investigated. The effect of the pyrolysis temperature (623, 673, 773 and 873 K) and the type of solid heat carrier (sand and fumed silica) on the distribution of the heavy metals in birch and sunflower pyrolysis fractions are studied. The goal of the set-up is 'concentrating' heavy metals in the ash/char fraction after thermal treatment, preventing them to be released in the condensable and/or volatile fractions. The knowledge of the behaviour of heavy metals affects directly future applications and valorisation of the pyrolysis products and thus contaminated biomass. They are indispensable for making and selecting the proper thermal conditions for their maximum recovery. In view of the future valorisation of these biomasses, the amounts of the pyrolysis fractions and the calorific values of the obtained liquid pyrolysis products, as a function of the pyrolysis temperature, are determined. 46 refs., 8 figs., 4 tabs.

  8. Synthesis, Characteristics and Potential Application of Poly(β-Amino Ester Urethane)-Based Multiblock Co-Polymers as an Injectable, Biodegradable and pH/Temperature-Sensitive Hydrogel System.

    Science.gov (United States)

    Huynh, Cong Truc; Nguyen, Minh Khanh; Jeong, In Ki; Kim, Sung Wan; Lee, Doo Sung

    2012-01-01

    Physical polymeric hydrogels have significant potential for use as injectable depot drug/protein-delivery systems. In this study, a series of novel injectable, biodegradable and pH/temperature-sensitive multiblock co-polymer physical hydrogels composed of poly(ethylene glycol) (PEG) and poly(β-amino ester urethane) (PEU) was synthesized by the polyaddition between the isocyanate groups of 1,6-diisocyanato hexamethylene and the hydroxyl groups of PEG and a synthesized monomer BTB (or ETE) in chloroform in the presence of dibutyltin dilaurate as a catalyst. The synthesized co-polymers were characterized by nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy and gel-permeation chromatography. Aqueous solutions of the co-polymers showed a sol-to-gel phase transition with increasing pH and a gel-to-sol phase transition with increasing temperature. The gel regions covered the physiological conditions (37°C, pH 7.4) and could be controlled by changing the molecular weight of PEG, PEG/PEU ratio and co-polymer solution concentration. A gel formed rapidly in situ after injecting the co-polymer solution subcutaneously into SD rats and remained for more than 2 weeks in the body. The cytotoxicity tests confirmed the non-cytotoxicity of this co-polymer hydrogel. The controlled in vitro release of the model anticancer drug, doxorubicin, from this hydrogel occurred over a 7-day period. This hydrogel is a potential candidate for biomedical applications and drug/protein-delivery systems.

  9. Low temperature rate coefficients of the H + CH{sup +} → C{sup +} + H{sub 2} reaction: New potential energy surface and time-independent quantum scattering

    Energy Technology Data Exchange (ETDEWEB)

    Werfelli, Ghofran [Université de Bordeaux, Institut des Sciences Moléculaires, CNRS UMR 5255, 33405 Talence Cedex (France); Faculté des Sciences de Tunis, Université de Tunis El-Manar, Laboratoire de Physique de la Matière Condensée, 2092 Tunis (Tunisia); Halvick, Philippe; Stoecklin, Thierry [Université de Bordeaux, Institut des Sciences Moléculaires, CNRS UMR 5255, 33405 Talence Cedex (France); Honvault, Pascal [Université de Bourgogne Franche-Comté, Laboratoire Interdisciplinaire Carnot de Bourgogne, CNRS UMR 6303, 21078 Dijon Cedex (France); Université de Franche-Comté, UFR ST, 25030 Besançon Cedex (France); Kerkeni, Boutheïna [Faculté des Sciences de Tunis, Université de Tunis El-Manar, Laboratoire de Physique de la Matière Condensée, 2092 Tunis (Tunisia); Institut Supérieur des Arts Multimédia de la Manouba, Université de la Manouba, 2010 la Manouba (Tunisia)

    2015-09-21

    The observed abundances of the methylidyne cation, CH{sup +}, in diffuse molecular clouds can be two orders of magnitude higher than the prediction of the standard gas-phase models which, in turn, predict rather well the abundances of neutral CH. It is therefore necessary to investigate all the possible formation and destruction processes of CH{sup +} in the interstellar medium with the most abundant species H, H{sub 2}, and e{sup −}. In this work, we address the destruction process of CH{sup +} by hydrogen abstraction. We report a new calculation of the low temperature rate coefficients for the abstraction reaction, using accurate time-independent quantum scattering and a new high-level ab initio global potential energy surface including a realistic model of the long-range interaction between the reactants H and CH{sup +}. The calculated thermal rate coefficient is in good agreement with the experimental data in the range 50 K–800 K. However, at lower temperatures, the experimental rate coefficient takes exceedingly small values which are not reproduced by the calculated rate coefficient. Instead, the latter rate coefficient is close to the one given by the Langevin capture model, as expected for a reaction involving an ion and a neutral species. Several recent theoretical works have reported a seemingly good agreement with the experiment below 50 K, but an analysis of these works show that they are based on potential energy surfaces with incorrect long-range behavior. The experimental results were explained by a loss of reactivity of the lowest rotational states of the reactant; however, the quantum scattering calculations show the opposite, namely, a reactivity enhancement with rotational excitation.

  10. Inner structure of La Fossa di Vulcano (Vulcano Island, southern Tyrrhenian Sea, Italy) revealed by high-resolution electric resistivity tomography coupled with self-potential, temperature, and CO2 diffuse degassing measurements

    Science.gov (United States)

    Revil, A.; Finizola, A.; Piscitelli, S.; Rizzo, E.; Ricci, T.; Crespy, A.; Angeletti, B.; Balasco, M.; Barde Cabusson, S.; Bennati, L.; BolèVe, A.; Byrdina, S.; Carzaniga, N.; di Gangi, F.; Morin, J.; Perrone, A.; Rossi, M.; Roulleau, E.; Suski, B.

    2008-07-01

    La Fossa cone is an active stratovolcano located on Vulcano Island in the Aeolian Archipelago (southern Italy). Its activity is characterized by explosive phreatic and phreatomagmatic eruptions producing wet and dry pyroclastic surges, pumice fall deposits, and highly viscous lava flows. Nine 2-D electrical resistivity tomograms (ERTs; electrode spacing 20 m, with a depth of investigation >200 m) were obtained to image the edifice. In addition, we also measured the self-potential, the CO2 flux from the soil, and the temperature along these profiles at the same locations. These data provide complementary information to interpret the ERT profiles. The ERT profiles allow us to identify the main structural boundaries (and their associated fluid circulations) defining the shallow architecture of the Fossa cone. The hydrothermal system is identified by very low values of the electrical resistivity (400 Ω m). Inside the crater it is possible to follow the plumbing system of the main fumarolic areas. On the flank of the edifice a thick layer of tuff is also marked by very low resistivity values (in the range 1-20 Ω m) because of its composition in clays and zeolites. The ashes and pyroclastic materials ejected during the nineteenth-century eruptions and partially covering the flank of the volcano correspond to relatively resistive materials (several hundreds to several thousands Ω m). We carried out laboratory measurements of the electrical resistivity and the streaming potential coupling coefficient of the main materials forming the volcanic edifice. A 2-D simulation of the groundwater flow is performed over the edifice using a commercial finite element code. Input parameters are the topography, the ERT cross section, and the value of the measured streaming current coupling coefficient. From this simulation we computed the self-potential field, and we found good agreement with the measured self-potential data by adjusting the boundary conditions for the flux of water

  11. Relações entre o potencial e a temperatura da folha de plantas de milho e sorgo submetidas a estresse hídrico = Relations between the potential and temperature of the corn and sorghum leafs submitted water stress

    Directory of Open Access Journals (Sweden)

    Pedro Abel Vieira Júnior

    2007-10-01

    Full Text Available Para avaliar o comportamento diário do potencial hídrico em plantas de milho e de sorgo submetidas a estresse hídrico, relacionando com as temperaturas foliar e ambiente, foram cultivadas, em vasos individuais em estufa, cinco plantas de cada espécie. Até o estádio fenológico de quatro folhas, o solo nos vasos foi mantido em capacidade de campo. Entre esse estádio e até próximo ao ponto de murcha a irrigação foi suspensa e foram monitoradas diariamente atemperatura ambiente (Tam, o potencial hídrico da folha (Ψfolha e a temperatura sobre a lâmina foliar (Tfoext. Nas plantas que apresentavam enrolamento das folhas, foram registradas astemperaturas (Tfoint da face interna do limbo enrolado. Também foram calculadas as médias horárias dos Ψ folha para ambas as espécies relacionando-os com a Tfoext, a Tfoint e as diferenças entreessas temperaturas. Ambas as espécies apresentaram comportamentos semelhantes quanto ao Ψ folha e entre 13 e 15 horas verificou-se o menor Ψ folha. Apesar da significativa relação inversa entrea Tfoext e o seu Ψ folha, em milho essa relação não apresenta acurácia para emprego da Tfoext no monitoramento do status hídrico da planta e a Tfoint é inferior à Tfoext, tornando-se um mecanismoque permite à planta a manutenção de seu metabolismo.To evaluate the daily behavior of the water potential in corn and of sorghum plants submitted to water stress, relating with the leaf and ambient temperature, were cultivated, in individual pots in greenhouse, five plants of each species. The plants were kept at field capacity until they reached the stage of four leaves. Between that stadium and close to the wilting point the irrigation was suspended and were monitored daily the ambient temperature (Tam, the water potential in the leaf (Ψ folha and the temperature on the leaf sheet (Tfoext. The plants whose leaves rolled up had their internal temperature measured (Tfoint. The average time of Ψ folha was

  12. Evaluación del potencial reproductivo del chorito (Mytilus chilensis de dos poblaciones naturales sometidas a diferentes temperaturas de acondicionamiento Assessment of the reproductive potential of the mussel (Mytilus chilensis from two natural populations subjected to different conditioning temperatures

    Directory of Open Access Journals (Sweden)

    Luis Lagos

    2012-07-01

    Full Text Available Mytilus chilensis tiene ciclos reproductivos que varían latitudinalmente. Presenta reducida diferenciación genética y morfológica debido a un gran potencial de dispersión. Se acondicionaron reproductores de bahía Yaldad (Chiloé y bahía Zenteno (Punta Arenas a 9 ± 0,5°C y 15 ± 0,5°C, alimentados con dieta (1:1 de Isochrysis galbana y Chaetoceros neogracile. Se espera dilucidar si el acondicionamiento a diferentes temperaturas produce variaciones en el potencial reproductivo de las poblaciones. El menor desarrollo gonadal se produjo en los reproductores acondicionados a 9°C, mientras que el mayor se produjo en los reproductores acondicionados a 15°C provenientes de Chiloé. La fecundidad de los reproductores de Yaldad fue mayor que los de Zenteno. El diámetro de los ovocitos fue mayor en los reproductores de Zenteno y en ambas poblaciones fue mayor a 9°C. Ni el porcentaje de huevos fecundados ni el porcentaje de eclosión de larvas D mostraron diferencias significativas entre las poblaciones a ninguna de las temperaturas de acondicionamiento. De acuerdo con estos resultados, no se logra establecer diferencias en el potencial reproductivo en las poblaciones y bajo las condiciones de este estudio.The reproductive cycles of Mytilus chilensis vary latitudinally. This species has reduced genetic and morphological differentiation due to its high potential for dispersal. Broodstocks from Yaldad Bay (Chiloé and Zenteno Bay (Punta Arenas were conditioned at 9 ± 0.5°C and 15 ± 0.5°C, and were fed a diet (1:1 of Isochrysis galbana and Chaetoceros neogracile. We expected to determine whether conditioning at different temperatures produces changes in the reproductive potential of the populations. Gonadal development was lowest in the broodstocks conditioned at 9°C, and highest in those conditioned at 15°C, from Chiloé. Fertility was greater in broodstocks from Yaldad than in those from Zenteno. Oocyte diameter was greater in broodstocks

  13. Electroweak relaxation from finite temperature

    CERN Document Server

    Hardy, Edward

    2015-01-01

    We study theories which naturally select a vacuum with parametrically small Electroweak Scale due to finite temperature effects in the early universe. In particular, there is a scalar with an approximate shift symmetry broken by a technically natural small coupling to the Higgs, and a temperature dependent potential. As the temperature of the universe drops, the scalar follows the minimum of its potential altering the Higgs mass squared parameter. The scalar also has a periodic potential with amplitude proportional to the Higgs expectation value, which traps it in a vacuum with a small Electroweak Scale. The required temperature dependence of the potential can occur through strong coupling effects in a hidden sector that are suppressed at high temperatures. Alternatively, it can be generated perturbatively from a one-loop thermal potential. In both cases, for the scalar to be displaced, a hidden sector must be reheated to temperatures significantly higher than the visible sector. However this does not violate...

  14. Mussel shells of Mytilus edulis as bioarchives of the distribution of rare earth elements and yttrium in seawater and the potential impact of pH and temperature on their partitioning behavior

    Science.gov (United States)

    Ponnurangam, A.; Bau, M.; Brenner, M.; Koschinsky, A.

    2016-02-01

    Mussel shells are potential bioarchives of proxies for changes in the physicochemical conditions in the bivalve's habitat. One such proxy is the distribution of rare earths and yttrium (REY) in seawater, as REY speciation in seawater is sensitive to pH and temperature variations, due to the impact of these parameters on the activity of CO32- in seawater. We present a new protocol for sample preparation and determination of ultratrace concentrations of REY in bulk bivalve shells (comprised of calcite and aragonite) that includes sample treatment with NaOCl followed by REY separation and preconcentration. The data obtained were used to calculate REY partition coefficients between bulk bimineralic shells of Mytilus edulis (calcite aragonite mix) and ambient seawater, and the results acquired were then used to investigate the potential effects of pH and temperature on REY partitioning.Shells of Mytilus edulis mussels from the North Sea show consistent shale-normalized (SN) REY patterns that increase from the light REY to the middle REY and decrease from the middle REY to the heavy REY. Despite being different from the general seawater REYSN pattern, the shells still display distinct REY features of seawater, such as a negative CeSN anomaly and small positive YSN and GdSN anomalies. Apparent REY partition coefficients between shells and seawater (appDTot.REYshell/seawater) are low and decrease strongly from the light REY (4.04 for La) to the heavy REY (0.34 for Lu). However, assuming that only the free REY3+ are incorporated into the shell, modDFreeREY3+shell/seawater values are higher and comparatively similar for all REY (102.46 for La; 113.44 for Lu) but show a slight maximum at Tb (199.18). Although the impact of vital effects, such as REY speciation in a mussel's extrapallial fluid from which the carbonate minerals precipitate, cannot be quantified yet, it appears that M. edulis shells are bioarchives of some REY features of seawater.We modeled the REYSN patterns

  15. Investigation of structural and electrochemical properties of LaSrCo1-xSbxO4 (0≤x≤0.20) as potential cathode materials in intermediate-temperature solid oxide fuel cells

    Science.gov (United States)

    Wang, Junkai; Zhou, Jun; Fan, Weiwei; Wang, Wendong; Wu, Kai; Cheng, Yonghong

    2017-03-01

    The structural and electrochemical properties of the layered perovskite oxides LaSrCo1-xSbxO4 (0≤x≤0.20) were investigated to study the effects of substituting Sb for Co for application as cathode materials in intermediate temperature solid oxide fuel cells (IT-SOFCs). The results of crystal structure analyses show the maximum content of Sb in LaSrCo1-xSbxO4 to be 0.05 as a pure single phase. XPS shows that Co and Sb in LaSrCo0.95Sb0.05O4 may possess mixed-oxidation states. The electrical conductivity increased greatly after Sb substitution. An improvement in the cathode polarization (Rp) values is observed from the Sb-doped sample with respect to the undoped samples. For example, Rp of LaSrCo0.95Sb0.05O4 on LSGM was observed to be 0.16 Ω cm2 at 800 °C in air. The main rate-limiting step for LaSrCo0.95Sb0.05O4 cathode is charge transfer of oxygen atoms. These results indicate that Sb can be incorporated into LaSrCo1-xSbxO4 based materials and can have a beneficial effect on the performance, making them potentially suitable for use as cathode materials in IT-SOFCs.

  16. Structural controls on fluid circulation at the Caviahue-Copahue Volcanic Complex (CCVC) geothermal area (Chile-Argentina), revealed by soil CO2 and temperature, self-potential, and helium isotopes

    Science.gov (United States)

    Roulleau, Emilie; Bravo, Francisco; Pinti, Daniele L.; Barde-Cabusson, Stéphanie; Pizarro, Marcela; Tardani, Daniele; Muñoz, Carlos; Sanchez, Juan; Sano, Yuji; Takahata, Naoto; de la Cal, Federico; Esteban, Carlos; Morata, Diego

    2017-07-01

    Natural geothermal systems are limited areas characterized by anomalously high heat flow caused by recent tectonic or magmatic activity. The heat source at depth is the result of the emplacement of magma bodies, controlled by the regional volcano-tectonic setting. In contrast, at a local scale a well-developed fault-fracture network favors the development of hydrothermal cells, and promotes the vertical advection of fluids and heat. The Southern Volcanic Zone (SVZ), straddling Chile and Argentina, has an important, yet unexplored and undeveloped geothermal potential. Studies on the lithological and tectonic controls of the hydrothermal circulation are therefore important for a correct assessment of the geothermal potential of the region. Here, new and dense self-potential (SP), soil CO2 and temperature (T) measurements, and helium isotope data measured in fumaroles and thermal springs from the geothermal area located in the north-eastern flank of the Copahue volcanic edifice, within the Caviahue Caldera (the Caviahue-Copahue Volcanic Complex - CCVC) are presented. Our results allowed to the constraint of the structural origin of the active thermal areas and the understanding of the evolution of the geothermal system. NE-striking faults in the area, characterized by a combination of SP, CO2, and T maxima and high 3He/4He ratios (up to 8.16 ± 0.21Ra, whereas atmospheric Ra is 1.382 × 10- 6), promote the formation of vertical permeability preferential pathways for fluid circulation. WNW-striking faults represent low-permeability pathways for hydrothermal fluid ascent, but promote infiltration of meteoric water at shallow depths, which dilute the hydrothermal input. The region is scattered with SP, CO2, and T minima, representing self-sealed zones characterized by impermeable altered rocks at depth, which create local barriers for fluid ascent. The NE-striking faults seem to be associated with the upflowing zones of the geothermal system, where the boiling process

  17. High Temperature Electrolysis

    DEFF Research Database (Denmark)

    Elder, Rachael; Cumming, Denis; Mogensen, Mogens Bjerg

    2015-01-01

    High temperature electrolysis of carbon dioxide, or co-electrolysis of carbon dioxide and steam, has a great potential for carbon dioxide utilisation. A solid oxide electrolysis cell (SOEC), operating between 500 and 900. °C, is used to reduce carbon dioxide to carbon monoxide. If steam is also...... input to the cell then hydrogen is produced giving syngas. This syngas can then be further reacted to form hydrocarbon fuels and chemicals. Operating at high temperature gives much higher efficiencies than can be achieved with low temperature electrolysis. Current state of the art SOECs utilise a dense...

  18. High Temperature Piezoelectric Drill

    Science.gov (United States)

    Bao, Xiaoqi; Scott, James; Boudreau, Kate; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Shrout, Tom; Zhang, Shujun

    2009-01-01

    The current NASA Decadal mission planning effort has identified Venus as a significant scientific target for a surface in-situ sampling/analyzing mission. The Venus environment represents several extremes including high temperature (460 deg C), high pressure (9 MPa), and potentially corrosive (condensed sulfuric acid droplets that adhere to surfaces during entry) environments. This technology challenge requires new rock sampling tools for these extreme conditions. Piezoelectric materials can potentially operate over a wide temperature range. Single crystals, like LiNbO3, have a Curie temperature that is higher than 1000 deg C and the piezoelectric ceramics Bismuth Titanate higher than 600 deg C. A study of the feasibility of producing piezoelectric drills that can operate in the temperature range up to 500 deg C was conducted. The study includes the high temperature properties investigations of engineering materials and piezoelectric ceramics with different formulas and doping. The drilling performances of a prototype Ultrasonic/Sonic Drill/Corer (USDC) using high temperate piezoelectric ceramics and single crystal were tested at temperature up to 500 deg C. The detailed results of our study and a discussion of the future work on performance improvements are presented in this paper.

  19. Temperature metrology

    Science.gov (United States)

    Fischer, J.; Fellmuth, B.

    2005-05-01

    The majority of the processes used by the manufacturing industry depend upon the accurate measurement and control of temperature. Thermal metrology is also a key factor affecting the efficiency and environmental impact of many high-energy industrial processes, the development of innovative products and the health and safety of the general population. Applications range from the processing, storage and shipment of perishable foodstuffs and biological materials to the development of more efficient and less environmentally polluting combustion processes for steel-making. Accurate measurement and control of temperature is, for instance, also important in areas such as the characterization of new materials used in the automotive, aerospace and semiconductor industries. This paper reviews the current status of temperature metrology. It starts with the determination of thermodynamic temperatures required on principle because temperature is an intensive quantity. Methods to determine thermodynamic temperatures are reviewed in detail to introduce the underlying physical basis. As these methods cannot usually be applied for practical measurements the need for a practical temperature scale for day-to-day work is motivated. The International Temperature Scale of 1990 and the Provisional Low Temperature Scale PLTS-2000 are described as important parts of the International System of Units to support science and technology. Its main importance becomes obvious in connection with industrial development and international markets. Every country is strongly interested in unique measures, in order to guarantee quality, reproducibility and functionability of products. The eventual realization of an international system, however, is only possible within the well-functioning organization of metrological laboratories. In developed countries the government established scientific institutes have certain metrological duties, as, for instance, the maintenance and dissemination of national

  20. Cold-active and NaCl-tolerant exo-inulinase from a cold-adapted Arthrobacter sp. MN8 and its potential for use in the production of fructose at low temperatures.

    Science.gov (United States)

    Zhou, Junpei; Lu, Qian; Peng, Mozhen; Zhang, Rui; Mo, Minghe; Tang, Xianghua; Li, Junjun; Xu, Bo; Ding, Junmei; Huang, Zunxi

    2015-03-01

    An exo-inulinase gene was cloned from Arthrobacter sp. MN8, a cold-adapted bacterium isolated from lead-zinc-rich soil. The gene was expressed in Escherichia coli BL21(DE3). The resultant 505-residue polypeptide (InuAMN8) showed the highest identity (81.1%) with the putative levanase from Arthrobacter phenanthrenivorans Sphe3 (ADX73279) and shared 57.8% identity with the exo-inulinase from Bacillus sp. snu-7 (AAK00768). The purified recombinant InuAMN8 (rInuAMN8) showed an apparently optimal activity at 35°C, and 75.3%, 39.4%, and 15.8% of its maximum activity at 20°C, 10°C, and 0°C, respectively. After pre-incubation for 60 min at 50°C and 55°C, the rInuAMN8 exhibited 69.8% and 17.7% of its initial activity, respectively. The apparent Km values of rInuAMN8 towards inulin were 2.8, 1.5, 1.2, 5.3, and 8.2 mM at 0°C, 10°C, 20°C, 30°C, and 35°C, respectively. Inulin and Jerusalem artichoke tubers were effectively hydrolyzed to release fructose by rInuAMN8 at 0°C, 10°C, and 35°C. Compared with its hyperthermophilic and thermophilic counterparts, the exo-inulinase had less aromatic amino acid F and more hydrophobic amino acid A. In addition, the purified rInuAMN8 retained 127.9%-88.4% inulinase activity at 3.5%-15.0% (w/v) NaCl concentrations. Zn(2+) and Pb(2+) at 10 mM exhibited little or no effect on the enzyme activity. This paper is the first to report a cold-active and/or NaCl-tolerant exo-inulinase from the genus Arthrobacter. The exo-inulinase rInuAMN8 shows a potential for use in the production of fructose at low temperatures. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  1. Sensing temperature.

    Science.gov (United States)

    Sengupta, Piali; Garrity, Paul

    2013-04-22

    Temperature is an omnipresent physical variable reflecting the rotational, vibrational and translational motion of matter, what Richard Feynman called the "jiggling" of atoms. Temperature varies across space and time, and this variation has dramatic effects on the physiology of living cells. It changes the rate and nature of chemical reactions, and it alters the configuration of the atoms that make up nucleic acids, proteins, lipids and other biomolecules, significantly affecting their activity. While life may have started in a "warm little pond", as Charles Darwin mused, the organisms that surround us today have only made it this far by devising sophisticated systems for sensing and responding to variations in temperature, and by using these systems in ways that allow them to persist and thrive in the face of thermal fluctuation.

  2. Effect of sintering temperature on the structural, dielectric and magnetic properties of Ni0.4Zn0.2Mn0.4Fe2O4 potential for radar absorbing

    Science.gov (United States)

    Praveena, K.; Sadhana, K.; Matteppanavar, S.; Liu, Hsiang-Lin

    2017-02-01

    Ni0.4Zn0.2Mn0.4Fe2O4 nanopowders were prepared by sol-gel auto-combustion method, densified at different temperatures 400-700 °C/4 h using conventional sintering method. The grain sizes of all the samples vary between 18 nm and 30 nm. The hysteresis loops show high saturation magnetization and low coercivity, indicating magnetically soft behaviour of the material. The real and imaginary parts of permittivity is almost constant upto 1 GHz and increases with further increase of frequency. The permeability is ruled by Snoek's law, the values of μ‧ increases with increase of temperature and the resonance frequency increases with an increase of temperature. The reflection coefficient is however increasing with sintering temperature and the maximum loss is observed in the range of 100 MHz-1 GHz. Sample sintered at 700 °C has shown maximum reflection loss and this loss occurs due to absorption, destructive interference and multiple internal reflections in the sample. Quality factor is constant upto 380 MHz and increases with frequency for all the samples sintered at different temperatures. The TC for all the samples is above 230 °C. The room temperature EPR spectra confirm the oxidation state of Fe3+. The g-factor is in the range of 2.

  3. Low temperature (

    NARCIS (Netherlands)

    Rath, J.K.; de Jong, M.; Schropp, R.E.I.

    2008-01-01

    Amorphous silicon films have been made by HWCVD at a very low substrate temperature of ≤ 100 °C (in a dynamic substrate heating mode) without artificial substrate cooling, through a substantial increase of the filament–substrate distance ( 80 mm) and using one straight tantalum filament. The materia

  4. High Temperature Capacitor Development

    Energy Technology Data Exchange (ETDEWEB)

    John Kosek

    2009-06-30

    unique high-temperature electrolyte developed during the course of the program. During this program the feasibility of operating a high voltage hybridized capacitor at 230oC was demonstrated. Capacitor specifications were established in conjunction with potential capacitor users. A method to allow for capacitor operation at both ambient and elevated temperatures was demonstrated. The program was terminated prior to moving into Phase II due to a lack of cost-sharing funds.

  5. Measurement and Calculation of Electrochemical Potentials in Hydrogenated High Temperature Water, including an Evaluation of the Yttria-Stabilized Zirconia/Iron-Iron Oxide (Fe/Fe3O4) Probe as Reference Electrode

    Energy Technology Data Exchange (ETDEWEB)

    Steven A. Attanasio; David S. Morton; Mark A. Ando

    2001-10-22

    The importance of knowing the electrochemical corrosion potential (ECP, also referred to as E{sub con}) of nickel-base alloys in hydrogenated water is related to the need to understand the effects of dissolved (i.e., aqueous) hydrogen concentration ([H{sub 2}]) on primary water stress corrosion cracking (PWSCC). Also, the use of a reference electrode (RE) can improve test quality by heightening the ability to detect instances of out-of-specification or unexpected chemistry. Three methods are used to measure and calculate the ECP of nickel-based alloys in hydrogenated water containing {approx} 1 to 150 scc/kg H{sub 2} (0.1 to 13.6 ppm H{sub 2}) at 260 to 360 C. The three methods are referred to as the specimen/component method, the platinum (Pt) method, and the yttria-stabilized zirconia/iron-iron oxide (YSZ/Fe-Fe{sub 3}O{sub 4}) RE method. The specimen/component method relies upon the assumption that the specimen or component behaves as a hydrogen electrode, and its E{sub corr} is calculated using the Nernst equation. The present work shows that this method is valid for aqueous H{sub 2} levels {ge} {approx} 5 to 10 scc/kg H{sub 2}. The Pt method uses a voltage measurement between the specimen or component and a Pt electrode, with the Pt assumed to behave as a hydrogen electrode; this method is valid as long as the aqueous H{sub 2}level is known. The YSZ/Fe-Fe{sub 3}O{sub 4}, which represents a relatively new approach for measuring E{sub corr} in this environment, can be used even if the aqueous H{sub 2} level is unknown. The electrochemical performance of the YSZ/Fe-Fe{sub 3}O{sub 4} probe supports its viability as a RE for use in high temperature hydrogenated water. Recent design modifications incorporating a teflon sealant have improved the durability of this RE (however, some of the REs do still fail prematurely due to water in-leakage). The Pt method is judged to represent the best overall approach, though there are cases where the other methods are superior

  6. Electroweak relaxation from finite temperature

    Science.gov (United States)

    Hardy, Edward

    2015-11-01

    We study theories which naturally select a vacuum with parametrically small Electroweak Scale due to finite temperature effects in the early universe. In particular, there is a scalar with an approximate shift symmetry broken by a technically natural small coupling to the Higgs, and a temperature dependent potential. As the temperature of the universe drops, the scalar follows the minimum of its potential altering the Higgs mass squared parameter. The scalar also has a periodic potential with amplitude proportional to the Higgs expectation value, which traps it in a vacuum with a small Electroweak Scale. The required temperature dependence of the potential can occur through strong coupling effects in a hidden sector that are suppressed at high temperatures. Alternatively, it can be generated perturbatively from a one-loop thermal potential. In both cases, for the scalar to be displaced, a hidden sector must be reheated to temperatures significantly higher than the visible sector. However this does not violate observational constraints provided the hidden sector energy density is transferred to the visible sector without disrupting big bang nucleosynthesis. We also study how the mechanism can be implemented when the visible sector is completed to the Minimal Supersymmetric Standard Model at a high scale. Models with a UV cutoff of 10 TeV and no fields taking values over a range greater than 1012 GeV are possible, although the scalar must have a range of order 108 times the effective decay constant in the periodic part of its potential.

  7. temperature overspecification

    Directory of Open Access Journals (Sweden)

    Mehdi Dehghan

    2001-01-01

    Full Text Available Two different finite difference schemes for solving the two-dimensional parabolic inverse problem with temperature overspecification are considered. These schemes are developed for indentifying the control parameter which produces, at any given time, a desired temperature distribution at a given point in the spatial domain. The numerical methods discussed, are based on the (3,3 alternating direction implicit (ADI finite difference scheme and the (3,9 alternating direction implicit formula. These schemes are unconditionally stable. The basis of analysis of the finite difference equation considered here is the modified equivalent partial differential equation approach, developed from the 1974 work of Warming and Hyett [17]. This allows direct and simple comparison of the errors associated with the equations as well as providing a means to develop more accurate finite difference schemes. These schemes use less central processor times than the fully implicit schemes for two-dimensional diffusion with temperature overspecification. The alternating direction implicit schemes developed in this report use more CPU times than the fully explicit finite difference schemes, but their unconditional stability is significant. The results of numerical experiments are presented, and accuracy and the Central Processor (CPU times needed for each of the methods are discussed. We also give error estimates in the maximum norm for each of these methods.

  8. High Temperature Piezoelectric Drill

    Science.gov (United States)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Shrout, Tom

    2012-01-01

    Venus is one of the planets in the solar systems that are considered for potential future exploration missions. It has extreme environment where the average temperature is 460 deg C and its ambient pressure is about 90 atm. Since the existing actuation technology cannot maintain functionality under the harsh conditions of Venus, it is a challenge to perform sampling and other tasks that require the use of moving parts. Specifically, the currently available electromagnetic actuators are limited in their ability to produce sufficiently high stroke, torque, or force. In contrast, advances in developing electro-mechanical materials (such as piezoelectric and electrostrictive) have enabled potential actuation capabilities that can be used to support such missions. Taking advantage of these materials, we developed a piezoelectric actuated drill that operates at the temperature range up to 500 deg C and the mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) configuration. The detailed results of our study are presented in this paper

  9. Temperature Gradient in Hall Thrusters

    Energy Technology Data Exchange (ETDEWEB)

    D. Staack; Y. Raitses; N.J. Fisch

    2003-11-24

    Plasma potentials and electron temperatures were deduced from emissive and cold floating probe measurements in a 2 kW Hall thruster, operated in the discharge voltage range of 200-400 V. An almost linear dependence of the electron temperature on the plasma potential was observed in the acceleration region of the thruster both inside and outside the thruster. This result calls into question whether secondary electron emission from the ceramic channel walls plays a significant role in electron energy balance. The proportionality factor between the axial electron temperature gradient and the electric field is significantly smaller than might be expected by models employing Ohmic heating of electrons.

  10. Compositions, thermodynamic properties, and transport coefficients of high-temperature C5F10O mixed with CO2 and O2 as substitutes for SF6 to reduce global warming potential

    Science.gov (United States)

    Zhong, Linlin; Rong, Mingzhe; Wang, Xiaohua; Wu, Junhui; Han, Guiquan; Han, Guohui; Lu, Yanhui; Yang, Aijun; Wu, Yi

    2017-07-01

    C5F10O has recently been found to be a very promising alternative to SF6. This paper is devoted to the investigation of compositions, thermodynamic properties, and transport coefficients of high-temperature C5F10O mixed with CO2 and O2. Firstly, the partition functions and enthalpies of formation for a few molecules (CxFy and CxFyO) which are likely to exist in the mixtures, are calculated based on the G4(MP2) theory. The isomers of the above molecules are selected according to their Gibbs energy. The compositions of C5F10O-CO2-O2 mixtures are then determined using the minimization of the Gibbs free energy. Next, the thermodynamic properties (mass density, specific enthalpy, and specific heat) are derived from the previously calculated compositions. Lastly, the transport coefficients (electrical conductivity, viscosity, and thermal conductivity) are calculated based on Chapman-Enskog method. It is found that, as an arc quenching gas, C5F10O could not recombine into itself with the temperature decreasing down to room temperature after the arc extinction. Besides, the key species at room temperature are always CF4, CO2, and C4F6 if graphite is not considered. When taken into account, graphite will replace C4F6 as one of the dominate particles. The mixing of CO2 with C5F10O plasma significantly affects the thermodynamic properties (e.g. vanishing and/or shifting of the peaks in specific heat) and transport coefficients (e.g. reducing viscosity and changing the number of peaks in thermal conductivity), while the addition of O2 with C5F10O-CO2 mixtures has no remarkable influence on both thermodynamic and transport properties.

  11. 最小二乘法在热电偶热电势—温度特性线性化中的应用%The application of least square method in the linear treatment of thermal potential-temperature character of the thermocouple

    Institute of Scientific and Technical Information of China (English)

    马松龄

    2001-01-01

    This paper introduces the application of least square method in the linear treatment for thermal potential-temperature character of thermocouple, and deduces formula for thermocouple temperature measurement. Based on these formula, the linear treatment of K thermocouple in temperature of 0~1400 ℃was given. The nonlinear error can be controlled under 1%with this method.%文中介绍了最小二乘法在热电偶热电势—温度特性线性化处理中的应用.推导出热电偶测温的拟合公式.利用这种方法,对K型热电偶在0~1 400 ℃进行了线性化处理后,所得的非线性误差可以控制到1 %以内.

  12. Potential Theory

    CERN Document Server

    Lukeš, Jaroslav; Netuka, Ivan; Veselý, Jiří

    1988-01-01

    Within the tradition of meetings devoted to potential theory, a conference on potential theory took place in Prague on 19-24, July 1987. The Conference was organized by the Faculty of Mathematics and Physics, Charles University, with the collaboration of the Institute of Mathematics, Czechoslovak Academy of Sciences, the Department of Mathematics, Czech University of Technology, the Union of Czechoslovak Mathematicians and Physicists, the Czechoslovak Scientific and Technical Society, and supported by IMU. During the Conference, 69 scientific communications from different branches of potential theory were presented; the majority of them are in­ cluded in the present volume. (Papers based on survey lectures delivered at the Conference, its program as well as a collection of problems from potential theory will appear in a special volume of the Lecture Notes Series published by Springer-Verlag). Topics of these communications truly reflect the vast scope of contemporary potential theory. Some contributions deal...

  13. Metabolic rates and tissue composition of the coral Pocillopora verrucosa over 12 latitudes in the Red Sea characterized by strong temperature and nutrient gradient, supplement to: Sawall, Yvonne; Al-Sofyani, A; Hohn, S; Banguera-Hinestroza, E; Voolstra, Christian R; Wahl, Martin (2015): Extensive phenotypic plasticity of a Red Sea coral over a strong latitudinal temperature gradient suggests limited acclimatization potential to warming. Scientific Reports, 5, 8940

    KAUST Repository

    Sawall, Yvonne

    2015-01-01

    Global warming was reported to cause growth reductions in tropical shallow water corals in both, cooler and warmer, regions of the coral species range. This suggests regional adaptation with less heat-tolerant populations in cooler and more thermo-tolerant populations in warmer regions. Here, we investigated seasonal changes in the in situ metabolic performance of the widely distributed hermatypic coral Pocillopora verrucosa along 12 degrees latitudes featuring a steep temperature gradient between the northern (28.5 degrees N, 21-27 degrees C) and southern (16.5 degrees N, 28-33 degrees C) reaches of the Red Sea. Surprisingly, we found little indication for regional adaptation, but strong indications for high phenotypic plasticity: Calcification rates in two seasons (winter, summer) were found to be highest at 28-29 degrees C throughout all populations independent of their geographic location. Mucus release increased with temperature and nutrient supply, both being highest in the south. Genetic characterization of the coral host revealed low inter-regional variation and differences in the Symbiodinium clade composition only at the most northern and most southern region. This suggests variable acclimatization potential to ocean warming of coral populations across the Red Sea: high acclimatization potential in northern populations, but limited ability to cope with ocean warming in southern populations already existing at the upper thermal margin for corals

  14. Violent Potentials

    DEFF Research Database (Denmark)

    Mikkelsen, Henrik Hvenegaard; Søgaard, Thomas Friis

    2015-01-01

    This article explores the social significance of violence as potentiality and performance among former headhunters. Taking its outset in an ethnographic study of violence and masculinity among the Philippine people known as the Bugkalot, we explore how violence as “performed violent potentiality......” plays a critical role in relation to Bugkalot men’s construction of hegemonic masculinity and the sustaining of complex egalitarian relations. The Bugkalot have a notoriously violent history; until the late 1970s more than half of the adult men engaged in ritual killings. While most Bugkalot men has...... today abandoned headhunting, the potentials for violence and dominance, which the act of headhunting sought to elicit, remains a critical aspect of masculinity. We propose that a focus on the social significance of performative violent potentiality among Bugkalot men can provide general insights...

  15. The potential impacts of temperature and nutrient levels on freshwater bacterioplankton community structure%温度和营养盐水平对淡水浮游细菌群落结构的潜在影响

    Institute of Scientific and Technical Information of China (English)

    陈祯; 何聃; 任丽娟

    2016-01-01

    To investigate bacterioplankton community composition (BCC)under different temperature and nutrient conditions,18 microcosms combining three temperature scenarios(15 ℃,25 ℃ and 35 ℃,respectively)and two nutrient levels(control and enriched)were established.After three months experiment,water environmental factors, plant biomass(mainly Filamentous green aglea,FGA),bacterioplankton community abundance and composition were studied.Extremely differences of DO,pH,NO-3-N,NO-2-N,FGA biomass were detected under different temperature and nutrient treatments.Both increased temperature (25 ℃ and 35 ℃)and nutrient enrichment stimulated the extensive growth of FGA.The proliferation of FGA had pronounced removal of water nutrients,so that the concentrations of N and P together with the bacterioplankton abundance were similar in nutrient enriched groups.In 1 5 ℃ treatments without nutrient enrichment,the influence of FGA was least and the nutrient concentrations were evidently higher than others,thus BCC there was pronouncedly different from the other treatments.Between 1 5 ℃ treatments without nutrient enrichment and the other treatments,the BCC divergence increased with the increasing differences of temperatures.In summary,we found that temperature and nutrient,as important abiotic factors for freshwater ecosystems,had complex interactions with plants and bacterioplankton community composition in freshwater ecosystem.The elevated temperature and nutrient conditions not only directly shifted BCC,but also indirectly impacted BCC through the growth of FGA.%为研究温度与水体营养条件对淡水浮游细菌群落的影响,进行室内模拟实验,设立了15℃、25℃和35℃三种温度处理和添加营养盐、未添加营养盐两种营养处理,总计6个处理组,每个处理组设计3个重复。实验结束后测定了环境因子、植物生物量、浮游细菌群落丰度和结构。结果发现,不同温度和营养盐条件下,环境中的 DO

  16. Core body temperature in obesity.

    Science.gov (United States)

    Heikens, Marc J; Gorbach, Alexander M; Eden, Henry S; Savastano, David M; Chen, Kong Y; Skarulis, Monica C; Yanovski, Jack A

    2011-05-01

    A lower core body temperature set point has been suggested to be a factor that could potentially predispose humans to develop obesity. We tested the hypothesis that obese individuals have lower core temperatures than those in normal-weight individuals. In study 1, nonobese [body mass index (BMI; in kg/m(2)) temperature-sensing capsules, and we measured core temperatures continuously for 24 h. In study 2, normal-weight (BMI of 18-25) and obese subjects swallowed temperature-sensing capsules to measure core temperatures continuously for ≥48 h and kept activity logs. We constructed daily, 24-h core temperature profiles for analysis. Mean (±SE) daily core body temperature did not differ significantly between the 35 nonobese and 46 obese subjects (36.92 ± 0.03°C compared with 36.89 ± 0.03°C; P = 0.44). Core temperature 24-h profiles did not differ significantly between 11 normal-weight and 19 obese subjects (P = 0.274). Women had a mean core body temperature ≈0.23°C greater than that of men (36.99 ± 0.03°C compared with 36.76 ± 0.03°C; P body temperature. It may be necessary to study individuals with function-altering mutations in core temperature-regulating genes to determine whether differences in the core body temperature set point affect the regulation of human body weight. These trials were registered at clinicaltrials.gov as NCT00428987 and NCT00266500.

  17. Ultrahigh-Temperature Ceramics

    Science.gov (United States)

    Johnson, Sylvia M.; Ellerby, Donald T.; Beckman, Sarah E.; Irby, Edward; Gasch, Matthew J.; Gusman, Michael I.

    2007-01-01

    Ultrahigh temperature ceramics (UHTCs) are a class of materials that include the diborides of metals such as hafnium and zirconium. The materials are of interest to NASA for their potential utility as sharp leading edges for hypersonic vehicles. Such an application requires that the materials be capable of operating at temperatures, often in excess of 2,000 C. UHTCs are highly refractory and have high thermal conductivity, an advantage for this application. UHTCs are potentially applicable for other high-temperature processing applications, such as crucibles for molten-metal processing and high-temperature electrodes. UHTCs were first studied in the 1960 s by the U.S. Air Force. NASA s Ames Research Center concentrated on developing materials in the HfB2/SiC family for a leading-edge application. The work focused on developing a process to make uniform monolithic (2-phase) materials, and on the testing and design of these materials. Figure 1 shows arc-jet models made from UHTC materials fabricated at Ames. Figure 2 shows a cone being tested in the arc-jet. Other variations of these materials being investigated elsewhere include zirconium based materials and fiber-reinforced composites. Current UHTC work at Ames covers four broad topics: monoliths, coatings, composites, and processing. The goals include improving the fracture toughness, thermal conductivity and oxidation resistance of monolithic UHTCs and developing oxidation-resistant UHTC coatings for thermal-protection-system substrates through novel coating methods. As part of this effort, researchers are exploring compositions and processing changes that have yielded improvements in properties. Computational materials science and nanotechnology are being explored as approaches to reduce materials development time and improve and tailor properties.

  18. Violent potentials

    DEFF Research Database (Denmark)

    Mikkelsen, Henrik Hvenegaard; Friis Søgaard, Thomas

    2016-01-01

    as ‘performed violent potentiality’ plays a critical role in relation to Bugkalot men’s construction of hegemonic masculinity and the sustaining of complex egalitarian relations. The Bugkalot have a notoriously violent history; until the late 1970s more than half of the adult men engaged in ritual killings......This article explores the social significance of violence as potentiality and performance among former headhunters engaged in ritual killings. Taking its outset in an ethnographic study of violence and masculinity among the Philippine people known as the Bugkalot, we explore how violence....... While most Bugkalot men have today abandoned headhunting, the potentials for violence and dominance, which the act of headhunting sought to elicit, remains a critical aspect of masculinity. We propose that a focus on the social significance of performative violent potentiality among Bugkalot men can...

  19. The potential for biocontrol in stored products in general, with specific attention to application of parasitoids against Sitophilus granarius in grains stores at low temperatures

    DEFF Research Database (Denmark)

    Hansen, Lise Stengård

    : This presentation will give an overview of the current state of biocontrol in stored products. An EU-funded COST Action Working Group, active during 2000-2006. evaluated the possibilities in different sectors: grain stores, mills and bakeries, pasta factories, stored nuts and dried fruit, etc. Three situations were...... identified with the greatest potential for widespread application: (1) empty room treatment against mites, beetles and moths, (2) treatment of bulk commodities against Sitophilus spp. and mites, and (3) application of egg-parasitoids against moths in packaged products. As an example, results of research...

  20. Violent Potentials

    DEFF Research Database (Denmark)

    Mikkelsen, Henrik Hvenegaard; Søgaard, Thomas Friis

    2015-01-01

    This article explores the social significance of violence as potentiality and performance among former headhunters. Taking its outset in an ethnographic study of violence and masculinity among the Philippine people known as the Bugkalot, we explore how violence as “performed violent potentiality”...

  1. Corrosion Resistant Coatings for High Temperature Applications

    Energy Technology Data Exchange (ETDEWEB)

    Besman, T.M.; Cooley, K.M.; Haynes, J.A.; Lee, W.Y.; Vaubert, V.M.

    1998-12-01

    Efforts to increase efficiency of energy conversion devices have required their operation at ever higher temperatures. This will force the substitution of higher-temperature structural ceramics for lower temperature materials, largely metals. Yet, many of these ceramics will require protection from high temperature corrosion caused by combustion gases, atmospheric contaminants, or the operating medium. This paper discusses examples of the initial development of such coatings and materials for potential application in combustion, aluminum smelting, and other harsh environments.

  2. Potential of nitrate addition to control the activity of sulfate-reducing prokaryotes in high-temperature oil production systems - a comparative study on a nitrate-treated and an untreated system

    DEFF Research Database (Denmark)

    Gittel, Antje; Sørensen, Ketil; Skovhus, Torben L.

    Sulfate-reducing prokaryotes (SRP) cause severe problems like microbial corrosion and reservoir souring in seawater-injected oil production systems. Adding nitrate to the injection water is applied to control SRP activity by favoring the growth of heterotrophic, nitrate-reducing bacteria (h......NRB) and nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB). Microbial diversity, abundance of Bacteria, Archaea and sulfate-reducing prokaryotes (SRP) and the potential activity of SRP were studied in production water samples from a nitrate-treated and an untreated system. The reservoirs and the produced water...... share similar physicochemical characteristics. At both sites, Archaea and Archaeoglobus-related SRP dominated the total prokaryotic and the sulfate-reducing community, respectively. It was however indicated from clone libraries and the quantification of 16S rRNA and dsrAB gene copies that Archaeoglobus...

  3. Potential theory

    CERN Document Server

    Helms, Lester L

    2014-01-01

    Potential Theory presents a clear path from calculus to classical potential theory and beyond, with the aim of moving the reader into the area of mathematical research as quickly as possible. The subject matter is developed from first principles using only calculus. Commencing with the inverse square law for gravitational and electromagnetic forces and the divergence theorem, the author develops methods for constructing solutions of Laplace's equation on a region with prescribed values on the boundary of the region. The latter half of the book addresses more advanced material aimed at those with the background of a senior undergraduate or beginning graduate course in real analysis. Starting with solutions of the Dirichlet problem subject to mixed boundary conditions on the simplest of regions, methods of morphing such solutions onto solutions of Poisson's equation on more general regions are developed using diffeomorphisms and the Perron-Wiener-Brelot method, culminating in application to Brownian motion. In ...

  4. Potentiel et limites d'utilisation, aux températures élevées, des lubrifiants liquides dans les moteurs Potential and Limitations of Use of Liquid Lubricants in Engines At High Temperatures

    Directory of Open Access Journals (Sweden)

    Toulhoat H.

    2006-11-01

    favorable. Les nouvelles formules à développer devront naturellement conserver les propriétés désirables telles que les effets anti-usure et anti-corrosion, la détergence, le pouvoir dispersant, et une bonne aptitude à l'écoulement à basse température. Les solutions techniques sont assurément à la portée de l'industrie des lubrifiants, mais au prix d'un effort de développement qui ne doit pas être sous-estimé, et cette valeur ajoutée aura dans une certaine mesure des conséquences sur les coûts. En même temps que les températures opératoires s'élèveront, de nouveaux matériaux continueront leur pénétration en tant que pièces de frottement ou barrières thermiques : les composites, les cermets, les métaux durcis superficiellement, les revêtements céramiques ou les céramiques massives. Il s'avère que les céramiques thermo-mécaniques non lubrifiées ne fonctionnent pas. D'un autre côté, les lubrifiants pourraient étendre le champ d'application des pièces de friction non métalliques en régime de lubrification limite, ou en tant que solutions à des problèmes de fatigue. On donne des exemples de formation de films interfaciaux protecteurs par réaction du DTPZn dans des conditions de frottement représentatives, avec de la zircone pure, du nitrure de silicium et de l'oxyde de chrome déposé par plasma sur de l'acier et de l'aluminium. Les coefficients de frottement se situent dans le domaine 0,03-0,1, valeurs comparables à celles des contacts métal-métal en régime de lubrification limite. This article examines the possible responses of lubricant formulations to a rise of temperatures in engines in the next decade. The increase in the specific powers of engines and the reduction of their overall dimensions and weights, the penetration of turbocompressors and catalytic mufflers, and, to some extent, a tendency to reduce heat discharges are driving forces for such a rise. An increase in the mean temperature at the oil gallery by about 15

  5. Corrosion behaviour of sintered Ti–Ni–Cu–Nb in 0.9% NaCl environment

    Directory of Open Access Journals (Sweden)

    Moipone Linda Lethabane

    2015-10-01

    Full Text Available The uniform and localized corrosion behaviour of sintered Ti–Ni containing niobium and copper additions were studied using potentiodynamic and cyclic polarization measurements in 0.9% sodium chloride. Results indicated that copper and niobium addition did not have significant effects on the uniform corrosion characteristics, but significantly improved the pitting corrosion resistance. Both copper and niobium additions significantly increased the re-passivation potentials, while copper was observed to reduce the pitting hysteresis loop area. Alloys containing 15% copper and 2% niobium additions depicted the most improved pitting corrosion resistance, and increased the re-passivation value from −315.60 mV to a high re-passivation potential of 840.68 mV.

  6. Therapeutic ultrasound as a potential male contraceptive: power, frequency and temperature required to deplete rat testes of meiotic cells and epididymides of sperm determined using a commercially available system

    Directory of Open Access Journals (Sweden)

    Tsuruta James K

    2012-01-01

    Full Text Available Abstract Background Studies published in the 1970s by Mostafa S. Fahim and colleagues showed that a short treatment with ultrasound caused the depletion of germ cells and infertility. The goal of the current study was to determine if a commercially available therapeutic ultrasound generator and transducer could be used as the basis for a male contraceptive. Methods Sprague-Dawley rats were anesthetized and their testes were treated with 1 MHz or 3 MHz ultrasound while varying power, duration and temperature of treatment. Results We found that 3 MHz ultrasound delivered with 2.2 Watt per square cm power for fifteen minutes was necessary to deplete spermatocytes and spermatids from the testis and that this treatment significantly reduced epididymal sperm reserves. 3 MHz ultrasound treatment reduced total epididymal sperm count 10-fold lower than the wet-heat control and decreased motile sperm counts 1,000-fold lower than wet-heat alone. The current treatment regimen provided nominally more energy to the treatment chamber than Fahim's originally reported conditions of 1 MHz ultrasound delivered at 1 Watt per square cm for ten minutes. However, the true spatial average intensity, effective radiating area and power output of the transducers used by Fahim were not reported, making a direct comparison impossible. We found that germ cell depletion was most uniform and effective when we rotated the therapeutic transducer to mitigate non-uniformity of the beam field. The lowest sperm count was achieved when the coupling medium (3% saline was held at 37 degrees C and two consecutive 15-minute treatments of 3 MHz ultrasound at 2.2 Watt per square cm were separated by 2 days. Conclusions The non-invasive nature of ultrasound and its efficacy in reducing sperm count make therapeutic ultrasound a promising candidate for a male contraceptive. However, further studies must be conducted to confirm its efficacy in providing a contraceptive effect, to test the

  7. [On Atomic Nuclear Fusion Processes at Low-Temperatures. An Enhancement of the Probability of Transition through a Potential Barrier Due to the So-Called Barrier Anti-Zeno Effect].

    Science.gov (United States)

    Namiot, V A

    2016-01-01

    It is known that in quantum mechanics the act of observing the experiment can affect the experimental findings in some cases. In particular, it happens under the so-called Zeno effect. In this work it is shown that in contrast to the "standard" Zeno-effect where the act of observing a process reduces the probability of its reality, an inverse situation when a particle transmits through a potential barrier (a so-called barrier anti-Zeno effect) can be observed, the observation of the particle essentially increases the probability of its transmission through the barrier. The possibility of using the barrier anti-Zeno effect is discussed to explain paradoxical results of experiments on "cold nuclear fusion" observed in various systems including biological ones. (According to the observers who performed the observations, the energy generation, which could not be explained by any chemical processes, as well as the change in the isotope and even element composition of the studied object may occur in these systems.

  8. Effect of Potential Range in Pressure-Temperature Behavior in Isotropic-Nematic Transition of 4-4´-Bis(EthyloxyAzoxybenzene (P-Azoxyphenetole, Pap, 4-Pentyl-4´-Cyanobiphenyl (5cb, P-Methoxybenzydidene-P-N-Butylaniline (Mbba and P–Ethoxybenzylidene–P–N-Butylaniline (Ebba

    Directory of Open Access Journals (Sweden)

    García-Sánchez E.

    2011-04-01

    Full Text Available In this work we employed the Density Functional Theory (IPCM model to calculate molecular volume and k, and the perturbation theory proposed by García-Sánchez et al. (2002 to predict phase diagram and experimental behavior pressure-temperature for isotropic-nematic transition of 4-4´-bis(ethyloxyazoxybenzene (p-azoxyphenetole, PAP, 4-pentyl-4´-cyanobiphenyl (5CB, p-methoxybenzydidene-p-n-butylaniline (MBBA and p–ethoxybenzylidene–p–n-butylaniline (EBBA at 1 atm. If during the theoretical prediction bigger potential values of potential range of square well (l > k are considered in the theoretical model, it is possible to get better prediction of the experimental behavior. The above mentioned is according with the theoretical formulation of the Second Order Perturbation Theory since Ponce-Renon approximation is included.

  9. Zero Temperature Hope Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Rozsnyai, B F

    2002-07-26

    The primary purpose of the HOPE code is to calculate opacities over a wide temperature and density range. It can also produce equation of state (EOS) data. Since the experimental data at the high temperature region are scarce, comparisons of predictions with the ample zero temperature data provide a valuable physics check of the code. In this report we show a selected few examples across the periodic table. Below we give a brief general information about the physics of the HOPE code. The HOPE code is an ''average atom'' (AA) Dirac-Slater self-consistent code. The AA label in the case of finite temperature means that the one-electron levels are populated according to the Fermi statistics, at zero temperature it means that the ''aufbau'' principle works, i.e. no a priory electronic configuration is set, although it can be done. As such, it is a one-particle model (any Hartree-Fock model is a one particle model). The code is an ''ion-sphere'' model, meaning that the atom under investigation is neutral within the ion-sphere radius. Furthermore, the boundary conditions for the bound states are also set at the ion-sphere radius, which distinguishes the code from the INFERNO, OPAL and STA codes. Once the self-consistent AA state is obtained, the code proceeds to generate many-electron configurations and proceeds to calculate photoabsorption in the ''detailed configuration accounting'' (DCA) scheme. However, this last feature is meaningless at zero temperature. There is one important feature in the HOPE code which should be noted; any self-consistent model is self-consistent in the space of the occupied orbitals. The unoccupied orbitals, where electrons are lifted via photoexcitation, are unphysical. The rigorous way to deal with that problem is to carry out complete self-consistent calculations both in the initial and final states connecting photoexcitations, an enormous computational task

  10. 植物根际及土壤有机碳含量和温度对湿地甲烷产生潜力的影响%Effect of Organic Carbon Content and Temperature at Plant Rhizosphere and Soil on Production Potential of Wetland Methane

    Institute of Scientific and Technical Information of China (English)

    姚晓东; 陈重安; 黄佳芳

    2013-01-01

    在全球气候变化的大背景下,湿地甲烷的产生和排放的研究引起广泛关注。以闽江口3种沼泽湿地土壤为研究对象,通过室内厌氧培养实验测定了距植株不同距离的湿地表层土壤的甲烷产生潜力值,研究了不同土壤有机质含量和培养温度对甲烷产生潜力的影响。结果表明:①芦苇和互花米草湿地近根际土壤甲烷产生潜力显著高于远根际土壤,而且根系越发达,相关性越大;②经过相关性分析,土壤有机碳含量和培养温度与甲烷产生潜力呈显著正相关,而且温度越高影响越显著。%In the context of global climate change, the formation and emission of wetland methane has received widespread attention. Soils of 3 types of marsh in the Minjiang river estuary were studied. Indoor anaerobic incubation experiment was used to measure the methane production potential of surface soil at different distances from the test plants. The effect of soil organic carbon and culture temperature on the methane production potential was also studied. Results showed that, in the wetland of Phragmites australis and Spartina alterniflora, methane production potential of soils near rhizosphere were higher than that at longer distances. Correlation analysis demonstrated that soil organic carbon and culture temperature were significantly positively correlated with the methane production potential.

  11. Temperature compensation and entrainment in circadian rhythms

    Science.gov (United States)

    Bodenstein, C.; Heiland, I.; Schuster, S.

    2012-06-01

    To anticipate daily variations in the environment and coordinate biological activities into a daily cycle many organisms possess a circadian clock. In the absence of external time cues the circadian rhythm persists with a period of approximately 24 h. The clock phase can be shifted by single pulses of light, darkness, chemicals, or temperature and this allows entrainment of the clock to exactly 24 h by cycles of these zeitgebers. On the other hand, the period of the circadian rhythm is kept relatively constant within a physiological range of constant temperatures, which means that the oscillator is temperature compensated. The mechanisms behind temperature compensation and temperature entrainment are not fully understood, neither biochemically nor mathematically. Here, we theoretically investigate the interplay of temperature compensation and entrainment in general oscillatory systems. We first give an analytical treatment for small temperature shifts and derive that every temperature-compensated oscillator is entrainable to external small-amplitude temperature cycles. Temperature compensation ensures that this entrainment region is always centered at the endogenous period regardless of possible seasonal temperature differences. Moreover, for small temperature cycles the entrainment region of the oscillator is potentially larger for rectangular pulses. For large temperature shifts we numerically analyze different circadian clock models proposed in the literature with respect to these properties. We observe that for such large temperature shifts sinusoidal or gradual temperature cycles allow a larger entrainment region than rectangular cycles.

  12. Electrochemical Study of Welded AISI 304 and 904L Stainless Steel in Seawater in View of Corrosion

    Directory of Open Access Journals (Sweden)

    Richárd Székely

    2010-10-01

    Full Text Available This is a comparative study of the corrosion behaviour of welds in AISI 304 and AISI 904L stainless steels carried out in seawater model solution in the temperature range 5-35°C and the standard of corrosion testing of welds was followed. The corrosion rate and corrosion attack characteristics were determined for welds of the examined steels with several type of treatment. The aim of this work was to compare the steels based on their resistance against the corrosion in terms of pitting potential (Epit and repassivation potential (Erepass. Seawater is an electrochemically aggressive medium, which can initiate localised corrosion in welded stainless steels. Different electrochemical and testing methods were used, including cyclic voltammetry, chronopotentiometry, electrochemical impedance spectroscopy (EIS, pH measuring and penetration tests.

  13. Biomethanation and Its Potential

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Karakashev, Dimitar Borisov; Batstone, Damien J.;

    2011-01-01

    matter via cascades of biochemical conversions to methane and carbon dioxide. Syntrophic relationships between hydrogen producers (acetogens) and hydrogen scavengers (homoacetogens, hydrogenotrophic methanogens, etc.) are critical to the process. Determination of practical and theoretical methane...... potential is very important for design for optimal process design, configuration, and effective evaluation of economic feasibility. A wide variety of process applications for biomethanation of wastewaters, slurries, and solid waste have been developed. They utilize different reactor types (fully mixed......, plugflow, biofilm, UASB, etc.) and process conditions (retention times, loading rates, temperatures, etc.) in order to maximize the energy output from the waste and also to decrease retention time and enhance process stability. Biomethanation has strong potential for the production of energy from organic...

  14. 基于运行时间的变频型房间空调器季节能效比和潜力温度分析%Study on Seasonal Energy Efficiency Ratio and Potential Temperature of Variable-Speed Room Air Conditioner Based on Running Time

    Institute of Scientific and Technical Information of China (English)

    田镇; 谷波

    2013-01-01

    Seasonal energy efficiency ratio (SEER) of three variable-speed air conditioners under three kinds of running time was analyzed, respectively. Running time frequency (RTF) was taken to characterize the distribution of running time on temperature intervals. Bar graph was used to show the distribution of cooling load and energy consumption on temperature intervals. The results show that, the smaller the temperature under maximum RTF, the higher the SEER is. The faster the accumulation speed of RTF on low temperature intervals, the higher the SEER is. The regularity of distribution of cooling load and energy consumption on temperature intervals is decided by running time. The potential temperature can be showed on the bar graph, which has high reference value in performance optimization and selection of variable-speed room air conditioner.%计算了3台变频型房间空调器基于北京、上海、广州3种运行时间的季节能效比(SEER);采用运行时间频数(RTF)表征空调器运行时间在温度区间上的分布规律;绘制了3台空调器基于3种运行时间的制冷量和耗电量分布图.结果表明:RTF最大值对应的温度越小,SEER越大;RTF在低温段累计速度越快,SEER越大;空调器制冷量和耗电量在温度区间上的分布规律由运行时间决定;基于运行时间的制冷量和耗电量分布图能够直观反映当地的潜力温度,可为空调器性能的优化和选型提供参考依据.

  15. Pathophysiology of Temperature Regulation.

    Science.gov (United States)

    Mitchell, D.; Laburn, Helen P.

    1985-01-01

    Discusses: (1) measurement of body temperature; (2) normal deviations from normal body temperature; (3) temperature in the very young and the very old; (4) abnormal liability of thermoregulation; (5) hyperthermia; (6) fever; and (7) hypothermia. (JN)

  16. High Temperature Materials Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The High Temperature Materials Lab provides the Navy and industry with affordable high temperature materials for advanced propulsion systems. Asset List: Arc Melter...

  17. Application Fields of High-Temperature Superconductors

    OpenAIRE

    Hott, Roland

    2003-01-01

    Potential application fields for cuprate high-temperature superconductors (HTS) and the status of respective projects are reviewed. The availability of a reliable and inexpensive cooling technique will be essential for a future broad acceptance of HTS applications.

  18. Temperature requirements of four entomopathogenic fungi

    Directory of Open Access Journals (Sweden)

    Ryszard Miętkiewski

    2014-08-01

    Full Text Available Infection potential of Beauvaria bassiana, Metarhizium anisopliae, Paecilomyces farinosus and P. fumosoroseus to G. mellonella larvae in pine litter was established. The growth of these fungi on the Czapek's Dox medium exposed to different temperature was determined.

  19. Industrial low temperature utilization of geothermal resources

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.

    1976-05-01

    This brief presentation on industrial utilization of low temperature geothermal resources first considers an overview of what has been achieved in using geothermal resources in this way and, second, considers potential, future industrial applications.

  20. 低温包埋渗铝及其在石油管材防腐蚀应用中的研究进展%Research Progress of Low-temperature Pack Aluminizing and Its Potential Application on Oil-casing Steel and Pipeline Steel

    Institute of Scientific and Technical Information of China (English)

    黄敏; 王宇

    2012-01-01

    慨述了钢基表面低温包埋渗铝的原理,分析了通过添加稀土元素、调整活性剂种类、在渗剂中添加合金、表面机械能助渗、基材表面自身纳米化预处理等实现低温渗铝的研究现状和优缺点.同时,针对高力学性能石油管材,提出了将表面自身纳米化技术与含锌的低温渗剂相结合的石油管材表面低温复合包埋渗铝技术,并对该技术在石油管材耐腐蚀保护方面的应用进行了展望,认为复合低温包埋渗铝技术在石油管材耐腐蚀处理中的应用具有广阔前景.%The main principle of low-temperature pack aluminizing of carbon steel was described. The present research situation and different characteristics of low-temperature pack aluminizing processing were analyzed by the addition of rare earth element, the adjustment of active agent type, the addition of alloy dement, the assistance of surface mechanical energy and the surface selmanocrystallization treatment of steel substrate. For oil-casing steel and pipeline steel with high mechanical properties, a combined low-temperature pack aluminizing for oil-casing steel and pipeline steel with surface nano-crystallization structure packed by powdeT with the addition of zinc was proposed. On the basis pf the potential corrosion resistance improvement of aluminized oil-casing steel and pipeline steel by combined low-temperature pack aluminizing, it can be concluded that the as-mentioned combined low-temperature pack aluminizing is hopeful for the wide application of aluminizing for the corrosion protection of oil-casing steel and pipeline steel.

  1. Potential power sources for high-temperature geothermal applications

    Energy Technology Data Exchange (ETDEWEB)

    Guidotti, R.A.; Dobranich, D

    1996-05-01

    The thermal response under geothermal-borehole conditions of a conventional thermal battery was evaluated for various designs by numerical simulations using a finite-element thermal model. This technology, which is based on molten salts, may be suitable as a power source for geothermal borehole applications for data logging. Several promising candidate electrolytes were identified for further study.

  2. Emergent Kink Statistics at Finite Temperature

    CERN Document Server

    Lopez-Ruiz, Miguel Angel; Szczepaniak, Adam P; Liao, Jinfeng

    2016-01-01

    In this paper we use 1D quantum mechanical systems with Higgs-like interaction potential to study the emergence of topological objects at finite temperature. Two different model systems are studied, the standard double-well potential model and a newly introduced discrete kink model. Using Monte-Carlo simulations as well as analytic methods, we demonstrate how kinks become abundant at low temperatures. These results may shed useful insights on how topological phenomena may occur in QCD.

  3. Temperature sensitivity of soil methane production potential in different marsh vegetation zones in the Min River estuary%闽江口不同沼泽植被带土壤甲烷产生潜力的温度敏感性

    Institute of Scientific and Technical Information of China (English)

    杨平; 何清华; 仝川

    2015-01-01

    2012年2月采集闽江河口鳝鱼滩短叶茳芏(Cyperus malaccensis),芦苇(Phragmites australis)和互花米草(Scirpus alterniflora)3个典型潮汐沼泽植被带0~30cm(间隔5cm)土壤样品,在不同温度(10,20和30℃)进行15d室内厌氧培养实验,探讨河口区不同沼泽植被带土壤甲烷产生潜力及其温度敏感性(Q10值)的特征.结果表明,指数模型较好地拟合不同沼泽植被带土壤甲烷产生与温度的相关关系;温度由10℃升至20℃时,3个沼泽植被带土壤甲烷产生潜力 Q10值的均值分别为5.04,14.92和14.81,最大值均在培养期间的第13~15d 分别出现于10~15cm,15~20cm和20~25cm三个土层;温度由20℃升至30℃时,3个沼泽植被带土壤甲烷产生潜力Q10值的均值分别为3.56,4.99和3.43,最大值分别在培养期间的第4~6d,第4~6d和第7~9d出现于0~5cm,0~5cm和15~20cm三个土层;植被类型和土壤深度对甲烷产生潜力及Q10值均具有显著的影响(P<0.05).%Quantifying response of soil methane production potential to temperature change in different wetland vegetation are vital to accurately evaluate effect of climate change on wetland ecosystem carbon balance. Soil samples at a depth of 0~30cm (5cm interval) from three typical tidal marsh ecosystems dominated byCyperus malaccensis, Phragmites australis andSpartina alterniflora, respectively, in the Min River estuary were collected in February 2012, and soil methane production potentials were determined using anaerobic incubation method. The results showed that there is an exponential correlation between methane production potential and soil temperature. The averagedQ10 value of three marsh vegetation zones were 5.04, 14.92, 14.81, and 3.56, 4.99, 3.43, respectively, with temperature rasing from 10 to 20℃ and from 20 to 30℃. Vegetation type, incubation temperature and soil depth had significant effects on the methane production potential andQ10 value (P<0.05).

  4. Recent Inland Water Temperature Trends

    Science.gov (United States)

    Hook, Simon; Healey, Nathan; Lenters, John; O'Reilly, Catherine

    2016-04-01

    We are using thermal infrared satellite data in conjunction with in situ measurements to produce water temperatures for all the large inland water bodies in North America and the rest of the world for potential use as climate indicator. Recent studies have revealed significant warming of inland waters throughout the world. The observed rate of warming is - in many cases - greater than that of the ambient air temperature. These rapid, unprecedented changes in inland water temperatures have profound implications for lake hydrodynamics, productivity, and biotic communities. Scientists are just beginning to understand the global extent, regional patterns, physical mechanisms, and ecological consequences of lake warming. As part of our work we have collected thermal infrared satellite data from those satellite sensors that provide long-term and frequent spaceborne thermal infrared measurements of inland waters including ATSR, AVHRR, and MODIS and used these to examine trends in water surface temperature for approximately 169 of the largest inland water bodies in the world. We are now extending this work to generate temperature time-series of all North American inland water bodies that are sufficiently large to be studied using 1km resolution satellite data for the last 3 decades, approximately 268 lakes. These data are then being related to changes in the surface air temperature and compared with regional trends in water surface temperature derived from CMIP5/IPCC model simulations/projections to better predict future temperature changes. We will discuss the available datasets and processing methodologies together with the patterns they reveal based on recent changes in the global warming, with a particular focus on the inland waters of the southwestern USA.

  5. Two-dimensional finite-element temperature variance analysis

    Science.gov (United States)

    Heuser, J. S.

    1972-01-01

    The finite element method is extended to thermal analysis by forming a variance analysis of temperature results so that the sensitivity of predicted temperatures to uncertainties in input variables is determined. The temperature fields within a finite number of elements are described in terms of the temperatures of vertices and the variational principle is used to minimize the integral equation describing thermal potential energy. A computer calculation yields the desired solution matrix of predicted temperatures and provides information about initial thermal parameters and their associated errors. Sample calculations show that all predicted temperatures are most effected by temperature values along fixed boundaries; more accurate specifications of these temperatures reduce errors in thermal calculations.

  6. High-temperature Titanium Alloys

    Directory of Open Access Journals (Sweden)

    A.K. Gogia

    2005-04-01

    Full Text Available The development of high-temperature titanium alloys has contributed significantly to the spectacular progress in thrust-to-weight ratio of the aero gas turbines. This paper presents anoverview on the development of high-temperature titanium alloys used in aero engines and potential futuristic materials based on titanium aluminides and composites. The role of alloychemistry, processing, and microstructure, in determining the mechanical properties of titanium alloys is discussed. While phase equilibria and microstructural stability consideration haverestricted the use of conventional titanium alloys up to about 600 "C, alloys based on TiPl (or,, E,AINb (0, TiAl (y, and titaniumltitanium aluminides-based composites offer a possibility ofquantum jump in the temperature capability of titanium alloys.

  7. Aeronautical applications of high-temperature superconductors

    Science.gov (United States)

    Turney, George E.; Luidens, Roger W.; Uherka, Kenneth; Hull, John

    1989-01-01

    The successful development of high-temperature superconductors (HTS) could have a major impact on future aeronautical propulsion and aeronautical flight vehicle systems. A preliminary examination of the potential application of HTS for aeronautics indicates that significant benefits may be realized through the development and implementation of these newly discovered materials. Applications of high-temperature superconductors (currently substantiated at 95 k) were envisioned for several classes of aeronautical systems, including subsonic and supersonic transports, hypersonic aircraft, V/STOL aircraft, rotorcraft, and solar, microwave and laser powered aircraft. Introduced and described are the particular applications and potential benefits of high-temperature superconductors as related to aeronautics and/or aeronautical systems.

  8. Aeronautical applications of high-temperature superconductors

    Science.gov (United States)

    Turney, George E.; Luidens, Roger W.; Uherka, Kenneth; Hull, John

    1989-01-01

    The successful development of high-temperature superconductors (HTS) could have a major impact on future aeronautical propulsion and aeronautical flight vehicle systems. A preliminary examination of the potential application of HTS for aeronautics indicates that significant benefits may be realized through the development and implementation of these newly discovered materials. Applications of high-temperature superconductors (currently substantiated at 95 K) were envisioned for several classes of aeronautical systems, including subsonic and supersonic transports, hypersonic aircraft, V/STOL aircraft, rotorcraft, and solar, microwave and laser powered aircraft. Introduced and described are the particular applications and potential benefits of high-temperature superconductors as related to aeronautics and/or aeronautical systems.

  9. Methods for Melting Temperature Calculation

    Science.gov (United States)

    Hong, Qi-Jun

    Melting temperature calculation has important applications in the theoretical study of phase diagrams and computational materials screenings. In this thesis, we present two new methods, i.e., the improved Widom's particle insertion method and the small-cell coexistence method, which we developed in order to capture melting temperatures both accurately and quickly. We propose a scheme that drastically improves the efficiency of Widom's particle insertion method by efficiently sampling cavities while calculating the integrals providing the chemical potentials of a physical system. This idea enables us to calculate chemical potentials of liquids directly from first-principles without the help of any reference system, which is necessary in the commonly used thermodynamic integration method. As an example, we apply our scheme, combined with the density functional formalism, to the calculation of the chemical potential of liquid copper. The calculated chemical potential is further used to locate the melting temperature. The calculated results closely agree with experiments. We propose the small-cell coexistence method based on the statistical analysis of small-size coexistence MD simulations. It eliminates the risk of a metastable superheated solid in the fast-heating method, while also significantly reducing the computer cost relative to the traditional large-scale coexistence method. Using empirical potentials, we validate the method and systematically study the finite-size effect on the calculated melting points. The method converges to the exact result in the limit of a large system size. An accuracy within 100 K in melting temperature is usually achieved when the simulation contains more than 100 atoms. DFT examples of Tantalum, high-pressure Sodium, and ionic material NaCl are shown to demonstrate the accuracy and flexibility of the method in its practical applications. The method serves as a promising approach for large-scale automated material screening in which

  10. HEAVY QUARK POTENTIALS AND QUARKONIA BINDING.

    Energy Technology Data Exchange (ETDEWEB)

    PETRECZKY,P.

    2004-11-04

    The author reviews recent progress in studying in-medium modification of inter-quark forces at finite temperature in lattice QCD. Some applications to the problem of quarkonium binding in potential models is also discussed.

  11. The influence of limb temperature and withdrawal time of muscle relaxants on somatosensory and motor evoked potential monitoring during surgery%肢体温度和肌松剂停药时间对术中SEP、MEP监测的影响

    Institute of Scientific and Technical Information of China (English)

    王金川; 王帆; 高宏志; 黄凤凤; 王翠娥; 刘金霞; 胡伟鹏

    2015-01-01

    objective To explore the influence of muscle relaxants and limb temperature on somatosensory evoked potential (SEP) and motor evoked potential ( MEP ) monitoring during surgery . Methods Clinical data of 35 patients undergoing intraoperative neurophysiological monitoring were analyzed retrospectively. According to limb temperature, the patients were divided into groupⅠ(less than 32℃) and groupⅡ(33 to 36℃). The amplitude and latency of SEP and MEP amplitude in the upper and lower limbs were analyzed and compared between the two groups. Results The SEP amplitudes in the upper and lower limbs were evidently less in groupⅠthan the groupⅡat 10, 30 and 60 min (P0.05). There was no difference in SEP latency in the upper and lower limbs between groupsⅠandⅡ(P>0.05). MEP amplitude of the upper and lower limbs in groupⅠraised slowly, reached peak at 60 min and kept high. MEP amplitude of the upper and lower limbs raised quickly and reached peak at 90 min and kept high in groupⅡ. SEP amplitude raised with the increase of muscle relaxant's administration time (P0.05). Conclusion Both the limb temperature and withdrawal time of muscle relaxants can influence the neuroelectrophysiological monitoring in brain surgery.%目的:探讨术中神经电生理监测过程中,肌松剂、温度对术中体感诱发电位(somatosensory evoked potential,SEP)、运动诱发电位(motor evoked potential,MEP)监测的影响。方法回顾性分析术中神经电生理监测的35例病人的临床资料,将术中病人肢体温度分为两组,Ⅰ组(肢体温度低于32℃)15例和Ⅱ组(肢体温度33~36℃)20例。对两组上下肢的SEP波幅﹑潜伏期和MEP波幅进行对比分析。结果Ⅰ组病人10、30、60 min的上、下肢SEP波幅明显小于Ⅱ组(P<0.05),但60 min以后两组并无差异(P>0.05)。Ⅰ组和Ⅱ组上、下肢SEP潜伏期差异不明显(P>0.05)。Ⅰ组中上、下肢MEP波幅上升缓慢,但在60 min上升到最高后维持高波幅,

  12. Temperature scaling method for Markov chains.

    Science.gov (United States)

    Crosby, Lonnie D; Windus, Theresa L

    2009-01-22

    The use of ab initio potentials in Monte Carlo simulations aimed at investigating the nucleation kinetics of water clusters is complicated by the computational expense of the potential energy determinations. Furthermore, the common desire to investigate the temperature dependence of kinetic properties leads to an urgent need to reduce the expense of performing simulations at many different temperatures. A method is detailed that allows a Markov chain (obtained via Monte Carlo) at one temperature to be scaled to other temperatures of interest without the need to perform additional large simulations. This Markov chain temperature-scaling (TeS) can be generally applied to simulations geared for numerous applications. This paper shows the quality of results which can be obtained by TeS and the possible quantities which may be extracted from scaled Markov chains. Results are obtained for a 1-D analytical potential for which the exact solutions are known. Also, this method is applied to water clusters consisting of between 2 and 5 monomers, using Dynamical Nucleation Theory to determine the evaporation rate constant for monomer loss. Although ab initio potentials are not utilized in this paper, the benefit of this method is made apparent by using the Dang-Chang polarizable classical potential for water to obtain statistical properties at various temperatures.

  13. Sustained Low Temperature NOx Reduction

    Energy Technology Data Exchange (ETDEWEB)

    Zha, Yuhui

    2017-04-05

    Increasing regulatory, environmental, and customer pressure in recent years led to substantial improvements in the fuel efficiency of diesel engines, including the remarkable breakthroughs demonstrated through the Super Truck program supported by the U.S. Department of Energy (DOE). On the other hand, these improvements have translated into a reduction of exhaust gas temperatures, thus further complicating the task of controlling NOx emissions, especially in low power duty cycles. The need for improved NOx conversion over these low temperature duty cycles is also observed as requirements tighten with in-use emissions testing. Sustained NOx reduction at low temperatures, especially in the 150-200oC range, shares some similarities with the more commonly discussed cold-start challenge, however poses a number of additional and distinct technical problems. In this project we set a bold target of achieving and maintaining a 90% NOx conversion at the SCR catalyst inlet temperature of 150oC. The project is intended to push the boundaries of the existing technologies, while staying within the realm of realistic future practical implementation. In order to meet the resulting challenges at the levels of catalyst fundamentals, system components, and system integration, Cummins has partnered with the DOE, Johnson Matthey, and Pacific Northwest National Lab and initiated the Sustained Low-Temperature NOx Reduction program at the beginning of 2015. Through this collaboration, we are exploring catalyst formulations and catalyst architectures with enhanced catalytic activity at 150°C; opportunities to approach the desirable ratio of NO and NO2 in the SCR feed gas; options for robust low-temperature reductant delivery; and the requirements for overall system integration. The program is expected to deliver an on-engine demonstration of the technical solution and an assessment of its commercial potential. In the SAE meeting, we will share the initial performance data on engine to

  14. The mechanocaloric potential of spin crossover compounds

    OpenAIRE

    Sandeman, K. G.

    2016-01-01

    We present a first evaluation of the potential for spin crossover (SCO) compounds to be considered as a new class of giant mechanocaloric effect material. From literature data on the variation of the spin crossover temperature with pressure, we estimate the maximum available adiabatic temperature change for several compounds and the relatively low pressures that may be required to observe these effects.

  15. HIGH TEMPERATURE DISPLACEMENT SENSOR

    Institute of Scientific and Technical Information of China (English)

    Xu Longxiang; Zhang Jinyu; Schweitzer Gerhard

    2005-01-01

    A high temperature displacement sensor based on the principle of eddy-current is investigated. A new temperature compensation technique by using eddy-current effect is presented to satisfy the special requirement at high temperature up to 550℃. The experiment shows that the temperature compensation technique leads to good temperature stability for the sensors. The variation of the sensitivity as well as the temperature drift of the sensor with temperature compensation technique is only about 7.4% and 90~350 mV at 550℃ compared with that at room temperature, and that of the sensor without temperature compensation technique is about 31.2% and 2~3 V at 550℃ compared with that at room temperature. A new dynamic calibration method for the eddy-current displacement sensor is presented, which is very easy to be realized especially in high frequency and at high temperatures. The high temperature displacement sensors developed are successfully used at temperature up to 550℃ in a magnetic bearing system for more than 100 h.

  16. Effects of the body temperature on the synthetic wave of electrocochleogram and brain stem auditory evoked potentials in guinea pigs%体温对豚鼠耳蜗电图-脑干听觉诱发电位综合波的影响

    Institute of Scientific and Technical Information of China (English)

    何斯纯; 马宁; 周卓妍; 周丽丽

    2005-01-01

    背景:脑干听觉诱发电位(brainstem auditory evoked potentials,BAEP)和耳蜗电图(electrocochleogram,ECochG)两者综合波的新记录方法具有特殊临床意义,探讨体温升高和体温降低对其的影响对进一步明确ECochG-BAEP综合波的生理特性和指导其临床应用有重要意义.目的:观察体温升高和体温降低对ECochG-BAEP综合波的影响效应.设计:随机区组设计.单位:暨南大学医学院生理教研室.对象:实验于2002-07/09在暨南大学医学院生理学教研室进行,选择成年豚鼠(300~350 g),雌雄不拘,由第一军医大学动物实验中心提供,随机分为体温降低组(20只)和体温升高组(20只).干预:体温降低组,体表物理降温法逐步降低豚鼠体温;体温升高组,体表物理升温法逐步升高豚鼠体温.主要观察指标:ECochG-BAEP综合波的波形、波峰潜伏期(PL)、波峰间潜伏期(IPL)和波幅随体温发生的变化.结果:随体温降低(36~25℃)和体温升高(36~42℃),ECochG-BAEP综合波波形始终兼具BAEP和ECochG两者的特点,有十分明显突出的1波;各波PL和IPL随体温降低而逐步延长,但随体温升高而逐渐缩短;1,2,3波波幅在体温降低至30~29℃时开始出现显著降低,1,2波波幅也在体温升高至40℃后开始出现显著降低.结论:体温降低和体温升高对ECochG-BAEP SW的PL,IPL和波幅均有显著影响,但其波形始终兼具BAEP和ECochG两者的特点.%BACKGROUND: A new method for recording the synthetic wave of electrocochleogram-brain stem auditory evoked potentials(ECochG-BAEP SW)has special clinical significance. The study of effects of hypothermia and hyperthermia on the synthetic wave is significant to define its physiological properties and to guide its clinical application.OBJECTIVE: To observe the effects of hypothermia and hyperthermia on ECochG-BAEP SW.DESIGN: A randomized block design.SETTING: Department of Physiology, Medical College of Jinan University

  17. Maine River Temperature Monitoring

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We collect seasonal and annual temperature measurements on an hourly or quarter hourly basis to monitor habitat suitability for ATS and other species. Temperature...

  18. GISS Surface Temperature Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The GISTEMP dataset is a global 2x2 gridded temperature anomaly dataset. Temperature data is updated around the middle of every month using current data files from...

  19. Body temperature norms

    Science.gov (United States)

    Morrison SF. Regulation of body temperature. In: Boron WF, Boulpaep EL, eds. Medical Physiology . 3rd ed. Philadelphia, PA: Elsevier; 2017:chap 59. Sajadi MM, Mackowiak PA. Temperature regulation and the pathogenesis of fever. In: Bennett JE, Dolin ...

  20. High temperature interfacial superconductivity

    Science.gov (United States)

    Bozovic, Ivan [Mount Sinai, NY; Logvenov, Gennady [Port Jefferson Station, NY; Gozar, Adrian Mihai [Port Jefferson, NY

    2012-06-19

    High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La.sub.2CuO.sub.4) and a metal (La.sub.1-xSr.sub.xCuO.sub.4), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, T.sub.c may be either .about.15 K or .about.30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, T.sub.c exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high T.sub.c phases and to significantly enhance superconducting properties in other superconductors. The superconducting interface may be implemented, for example, in SIS tunnel junctions or a SuFET.

  1. Rescaling Temperature and Entropy

    Science.gov (United States)

    Olmsted, John, III

    2010-01-01

    Temperature and entropy traditionally are expressed in units of kelvin and joule/kelvin. These units obscure some important aspects of the natures of these thermodynamic quantities. Defining a rescaled temperature using the Boltzmann constant, T' = k[subscript B]T, expresses temperature in energy units, thereby emphasizing the close relationship…

  2. Rescaling Temperature and Entropy

    Science.gov (United States)

    Olmsted, John, III

    2010-01-01

    Temperature and entropy traditionally are expressed in units of kelvin and joule/kelvin. These units obscure some important aspects of the natures of these thermodynamic quantities. Defining a rescaled temperature using the Boltzmann constant, T' = k[subscript B]T, expresses temperature in energy units, thereby emphasizing the close relationship…

  3. The role of hydrogen in negative bias temperature instability of pMOSFET

    Institute of Scientific and Technical Information of China (English)

    Li Zhong-He; Liu Hong-Xia; Hao Yue

    2006-01-01

    The NBTI degradation phenomenon and the role of hydrogen during NBT stress are presented in this paper.It is found that PBT stress can recover a fraction of Vth shift induced by NBTI.However,this recovery is unstable.The original degradation reappears soon after reapplication of the NBT stress condition.Hydrogen-related species play a key role during a device's NBT degradation.Experimental results show that the diffusion species are neutral.they repassivate Si dangling bond which is independent of the gate voltage polarity.In addition to the diffusion towards gate oxide,hydrogen diffusion to Si-substrate must be taken into account for it also has important influence on device degradation during NBT stress.

  4. Temperature Characteristics of BJMOSFET

    Institute of Scientific and Technical Information of China (English)

    ZENG Yun; YAN Min; YANG Hong-guan; GAO Yun

    2005-01-01

    The resolution expression for the temperature dependence of the current and threshold voltage is deduced as well as the analysis of temperature characteristics of BJMOSFET. Equivalent circuit of analysis and simulation has been established for the BJMOSFET temperature characteristics. By using the general circuit simulation software of PSpice9 and computer simulation, characteristic graphs of the BJMOSFET output characteristic, transient characteristic and amplitude-frequency characteristic with temperature variation are obtained. The results accorded very good with theoretical analysis and proved that BJMOSFET has better temperature characteristics than traditional MOSFET.

  5. Soil temperature variability in complex terrain measured using fiber-optic distributed temperature sensing

    Science.gov (United States)

    Soil temperature (Ts) exerts critical controls on hydrologic and biogeochemical processes but magnitude and nature of Ts variability in a landscape setting are rarely documented. Fiber optic distributed temperature sensing systems (FO-DTS) potentially measure Ts at high density over a large extent. ...

  6. High temperature catalytic membrane reactors

    Energy Technology Data Exchange (ETDEWEB)

    1990-03-01

    Current state-of-the-art inorganic oxide membranes offer the potential of being modified to yield catalytic properties. The resulting modules may be configured to simultaneously induce catalytic reactions with product concentration and separation in a single processing step. Processes utilizing such catalytically active membrane reactors have the potential for dramatically increasing yield reactions which are currently limited by either thermodynamic equilibria, product inhibition, or kinetic selectivity. Examples of commercial interest include hydrogenation, dehydrogenation, partial and selective oxidation, hydrations, hydrocarbon cracking, olefin metathesis, hydroformylation, and olefin polymerization. A large portion of the most significant reactions fall into the category of high temperature, gas phase chemical and petrochemical processes. Microporous oxide membranes are well suited for these applications. A program is proposed to investigate selected model reactions of commercial interest (i.e. dehydrogenation of ethylbenzene to styrene and dehydrogenation of butane to butadiene) using a high temperature catalytic membrane reactor. Membranes will be developed, reaction dynamics characterized, and production processes developed, culminating in laboratory-scale demonstration of technical and economic feasibility. As a result, the anticipated increased yield per reactor pass economic incentives are envisioned. First, a large decrease in the temperature required to obtain high yield should be possible because of the reduced driving force requirement. Significantly higher conversion per pass implies a reduced recycle ratio, as well as reduced reactor size. Both factors result in reduced capital costs, as well as savings in cost of reactants and energy.

  7. Soil Water and Temperature System (SWATS) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Bond, D

    2005-01-01

    The soil water and temperature system (SWATS) provides vertical profiles of soil temperature, soil-water potential, and soil moisture as a function of depth below the ground surface at hourly intervals. The temperature profiles are measured directly by in situ sensors at the Central Facility and many of the extended facilities of the SGP climate research site. The soil-water potential and soil moisture profiles are derived from measurements of soil temperature rise in response to small inputs of heat. Atmospheric scientists use the data in climate models to determine boundary conditions and to estimate the surface energy flux. The data are also useful to hydrologists, soil scientists, and agricultural scientists for determining the state of the soil.

  8. Chapter 6: Temperature

    Science.gov (United States)

    Jones, Leslie A.; Muhlfeld, Clint C.; Hauer, F. Richard; F. Richard Hauer,; Lamberti, G.A.

    2017-01-01

    Stream temperature has direct and indirect effects on stream ecology and is critical in determining both abiotic and biotic system responses across a hierarchy of spatial and temporal scales. Temperature variation is primarily driven by solar radiation, while landscape topography, geology, and stream reach scale ecosystem processes contribute to local variability. Spatiotemporal heterogeneity in freshwater ecosystems influences habitat distributions, physiological functions, and phenology of all aquatic organisms. In this chapter we provide an overview of methods for monitoring stream temperature, characterization of thermal profiles, and modeling approaches to stream temperature prediction. Recent advances in temperature monitoring allow for more comprehensive studies of the underlying processes influencing annual variation of temperatures and how thermal variability may impact aquatic organisms at individual, population, and community based scales. Likewise, the development of spatially explicit predictive models provide a framework for simulating natural and anthropogenic effects on thermal regimes which is integral for sustainable management of freshwater systems.

  9. Temperature measurement and control

    CERN Document Server

    Leigh, JR

    1988-01-01

    This book treats the theory and practice of temperature measurement and control and important related topics such as energy management and air pollution. There are no specific prerequisites for the book although a knowledge of elementary control theory could be useful. The first half of the book is an application oriented survey of temperature measurement techniques and devices. The second half is concerned mainly with temperature control in both simple and complex situations.

  10. High-Temperature Superconductivity

    Science.gov (United States)

    Tanaka, Shoji

    2006-12-01

    A general review on high-temperature superconductivity was made. After prehistoric view and the process of discovery were stated, the special features of high-temperature superconductors were explained from the materials side and the physical properties side. The present status on applications of high-temperature superconductors were explained on superconducting tapes, electric power cables, magnets for maglev trains, electric motors, superconducting quantum interference device (SQUID) and single flux quantum (SFQ) devices and circuits.

  11. Limiting Temperatures in Multifragmentation

    CERN Document Server

    Trautmann, W

    2008-01-01

    The systematic data set on isotopic effects in spectator fragmentation collected recently at the GSI laboratory permits the investigation of the N/Z dependence of the nuclear caloric curve which is of interest in several respects. In particular, new light is shed on the proposed interpretation of chemical breakup temperatures as a manifestation of the limiting temperatures predicted by t