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Sample records for heat affected zone

  1. Mechanical Properties of Heat Affected Zone of High Strength Steels

    NASA Astrophysics Data System (ADS)

    Sefcikova, K.; Brtnik, T.; Dolejs, J.; Keltamaki, K.; Topilla, R.

    2015-11-01

    High Strength Steels became more popular as a construction material during last decade because of their increased availability and affordability. On the other hand, even though general use of Advanced High Strength Steels (AHSS) is expanding, the wide utilization is limited because of insufficient information about their behaviour in structures. The most widely used technique for joining steels is fusion welding. The welding process has an influence not only on the welded connection but on the area near this connection, the so-called heat affected zone, as well. For that reason it is very important to be able to determine the properties in the heat affected zone (HAZ). This area of investigation is being continuously developed in dependence on significant progress in material production, especially regarding new types of steels available. There are currently several types of AHSS on the world market. Two most widely used processes for AHSS production are Thermo-Mechanically Controlled Processing (TMCP) and Quenching in connection with Tempering. In the presented study, TMCP and QC steels grade S960 were investigated. The study is focused on the changes of strength, ductility, hardness and impact strength in heat affected zone based on the used amount of heat input.

  2. Bead temperature effects on FCAW heat-affected zone hardness

    SciTech Connect

    Kiefer, J.H.

    1995-11-01

    Hardness limits for welding procedure qualification are often imposed to lessen the chances of delayed hydrogen cracking during production fabrication. Temper bead techniques have been used by fabricators during these qualifications to improve their chances of success. This practice involves using the heat of additional weld beads to soften the heat-affected zone (HAZ) hardness in the base metal next to the weld where the hardness is the greatest. The technique works under controlled conditions, but the consistency for field use was questionable. This report describes an investigate of the effect of welding parameters, base metal chemical composition, and weld bead placement on HAZ softening. An empirical formula developed from base plate chemical composition, weld cooling time, and temper bead placement can be used to estimate the amount of HAZ tempering. Combined with an appropriate hardness prediction formula, it can help find the welding procedure needed to achieve a desired maximum HAZ hardness, or predict the HAZ hardness of existing welds. Based on the results of the study, bead temperature is not recommended for HAZ hardness control on large scale fabrications.

  3. Validation of Temperature Histories for Structural Steel Welds Using Estimated Heat-Affected-Zone Edges

    DTIC Science & Technology

    2016-10-12

    Estimated Heat -Affected-Zone Edges October 12, 2016 Approved for public release; distribution is unlimited. S.G. LambrakoS Center for Computational Materials...PAGES 17. LIMITATION OF ABSTRACT Validation of Temperature Histories for Structural Steel Welds Using Estimated Heat -Affected-Zone Edges S.G. Lambrakos...experimentally measured estimates of the heat -affected-zone edge to examine the consistency of calculated temperature histories for steel welds. 12-10-2016 NRL

  4. Characteristics of GTA fusion zones and heat affected zones in superalloy 713C

    NASA Astrophysics Data System (ADS)

    Lachowicz, M. B.; Dudziński, W.

    2012-09-01

    In this paper, metallographic examinations, characterising microstructural changes in the 713C superalloy subjected to remelting by GTA method, are presented. In the fusion zone, precipitation of M23C6 or M6C carbides based on chromium and molybdenum was observed. Eutectic mixtures of ( γ- gg')-M x C y type with highly developed morphology were also perceived. It was found that, in the matrix areas with non-homogeneous chemical composition, the eutectic reaction γ-γ' can occur at the temperature close to that of the precipitation of the M x C y carbides. The presence of silicon in the carbide phases can be conducive to lowering their solidification point by creating low-melting compound NbSi. Both in the fusion zone (FZ) and in the heat-affected zone (HAZ), the secondary precipitates of the Ni3(AlTi)- γ' phase, varying in size from 50 to 100 nm, were found. The lattice mismatch factor of the γ and γ' particles was +0.48 % to +0.71 %, which is characteristic of the coherent precipitates of the Ni3Al phase enriched with titanium. No dislocations or stacking faults were observed in the microstructure of the FZ. In the HAZ, some primary undissolved γ' precipitates, with a part of aluminium probably replaced with niobium were observed, which raised their melting point.

  5. Fracture Behavior of Ultra-Low-Carbon Steel Plate and Heat-Affected-Zone.

    DTIC Science & Technology

    1990-12-01

    ganese-molybdenum steel caused an increase in the DBTT . However. it cannot be assumed that the presence of these TiN cubes always causes detrimental...Department Research & Development Report 0 N Fracture Behavior of Ultra-Low-Carbon Steel Plate and Heat-Affected-Zone by M. G. Vassilaros CO a- Co -e DTIC...Materials Engineering Department Research & Development Report Fracture Behavior of Ultra-Low-Carbon Steel Plate and Heat-Affected-Zone by M. G

  6. Microstructural response to heat affected zone cracking of prewelding heat-treated Inconel 939 superalloy

    SciTech Connect

    Gonzalez, M.A.; Garza, A.

    2011-12-15

    The microstructural response to cracking in the heat-affected zone (HAZ) of a nickel-based IN 939 superalloy after prewelding heat treatments (PWHT) was investigated. The PWHT specimens showed two different microstructures: 1) spherical ordered {gamma} Prime precipitates (357-442 nm), with blocky MC and discreet M{sub 23}C{sub 6} carbides dispersed within the coarse dendrites and in the interdendritic regions; and 2) ordered {gamma} Prime precipitates in 'ogdoadically' diced cube shapes and coarse MC carbides within the dendrites and in the interdendritic regions. After being tungsten inert gas welded (TIG) applying low heat input, welding speed and using a more ductile filler alloy, specimens with microstructures consisting of spherical {gamma} Prime precipitate particles and dispersed discreet MC carbides along the grain boundaries, displayed a considerably improved weldability due to a strong reduction of the intergranular HAZ cracking associated with the liquation microfissuring phenomena. - Highlights: Black-Right-Pointing-Pointer Homogeneous microstructures of {gamma} Prime spheroids and discreet MC carbides of Ni base superalloys through preweld heat treatments. Black-Right-Pointing-Pointer {gamma} Prime spheroids and discreet MC carbides reduce the intergranular HAZ liquation and microfissuring of Nickel base superalloys. Black-Right-Pointing-Pointer Microstructure {gamma} Prime spheroids and discreet blocky type MC carbides, capable to relax the stress generated during weld cooling. Black-Right-Pointing-Pointer Low welding heat input welding speeds and ductile filler alloys reduce the HAZ cracking susceptibility.

  7. Mechanical Properties and Microstructural Evolution of Simulated Heat-Affected Zones in Wrought Eglin Steel

    NASA Astrophysics Data System (ADS)

    Leister, Brett M.; DuPont, John N.; Watanabe, Masashi; Abrahams, Rachel A.

    2015-12-01

    A comprehensive study was performed to correlate the mechanical properties and microstructural evolution in the heat-affected zone of Eglin steel. A Gleeble 3500 thermo-mechanical simulator was used to simulate weld thermal cycles with different peak temperatures at a heat input of 1500 J/mm. These samples underwent mechanical testing to determine strength and toughness in the as-welded and post-weld heat-treated conditions. The inter-critical heat-affected zone (HAZ) had the lowest strength following thermal simulation, while the fine-grain and coarse-grain heat-affected zone exhibited increased strength when compared to the inter-critical HAZ. The toughness of the heat-affected zone in the as-simulated condition is lower than that of the base metal in all regions of the HAZ. Post-weld heat treatments (PWHTs) increased the toughness of the HAZ, but at the expense of strength. In addition, certain combinations of PWHTs within specific HAZ regions exhibited low toughness caused by tempered martensite embrittlement or intergranular failure. Synchrotron X-ray diffraction data have shown that Eglin steel has retained austenite in the fine-grain HAZ in the as-simulated condition. In addition, alloy carbides (M23C6, M2C, M7C3) have been observed in the diffraction spectra for the fine-grain and coarse-grain HAZ following a PWHT of 973 K (700 °C)/4 hours.

  8. Molecular dynamics simulation of heat-affected zone of copper metal ablated with femtosecond laser

    NASA Astrophysics Data System (ADS)

    Hirayama, Yoichi; Obara, Minoru

    2005-03-01

    Femtosecond laser ablation of materials with high thermal conductivity is of paramount importance, because the chemical composition and properties of the area ablated with femtosecond laser are kept unchanged. The material processing by femtosecond laser can well control the heat-affected zone, compared to nanosecond laser ablation. We report on the heat-affected zone of crystalline copper (Cu) by use of femtosecond laser experimentally and theoretically. Laser ablation of Cu is investigated theoretically by two temperature model and molecular dynamics (MD) simulation. The MD simulation takes into account of electron temperature and thermal diffusion length calculated by two temperature model. The dependence of lattice temperature on time and depth is calculated by the MD simulation and two temperature model. The heat-affected zone estimated from the temperature is mainly studied and calculated to be 3 nm at 0.02 J/cm2 which is below the threshold fluence of 0.137 J/cm2. In addition, the thickness of heat-affected zone of copper crystal ablated with femtosecond Ti:sapphire laser is experimentally studied. As a result of X-ray diffraction (XRD) of the ablated surface, the surface crystallinity is partially changed into disordered structure from crystal form. The residual energy left in the metal, which is not used for ablation, will induce liquid phase, leading to the amorphous phase of the metal during resolidification. The thickness of heat-affected zone depends on laser fluence and is experimentally measured to be less than 1 μm at higher laser fluences than the ablation threshold.

  9. Analysis of laser ablation dynamics of CFRP in order to reduce heat affected zone

    NASA Astrophysics Data System (ADS)

    Sato, Yuji; Tsukamoto, Masahiro; Nariyama, Tatsuya; Nakai, Kazuki; Matsuoka, Fumihiro; Takahashi, Kenjiro; Masuno, Shinichiro; Ohkubo, Tomomasa; Nakano, Hitoshi

    2014-03-01

    A carbon fiber reinforced plastic [CFRP], which has high strength, light weight and weather resistance, is attractive material applied for automobile, aircraft and so on. The laser processing of CFRP is one of suitable way to machining tool. However, thermal affected zone was formed at the exposure part, since the heat conduction property of the matrix is different from that of carbon fiber. In this paper, we demonstrated that the CFRP plates were cut with UV nanosecond laser to reduce the heat affected zone. The ablation plume and ablation mass were investigated by laser microscope and ultra-high speed camera. Furthermore, the ablation model was constructed by energy balance, and it was confirmed that the ablation rate was 0.028 μg/ pulse in good agreement with the calculation value of 0.03 μg/ pulse.

  10. Identification and Characterization of Intercritical Heat-Affected Zone in As-Welded Grade 91 Weldment

    NASA Astrophysics Data System (ADS)

    Wang, Yiyu; Kannan, Rangasayee; Li, Leijun

    2016-12-01

    A metallurgical method is proposed for locating the intercritical heat-affected zone in the as-welded Grade 91 steel. New austenitic grains, preferentially formed along the original prior austenite grain boundaries, are characterized to contain finer M23C6 carbides and higher strain levels than the original prior austenite grains. Kurdjumov-Sachs Group 1 variant pairs, with a low misorientation of 7 deg within a martensitic block, are identified as the dominant variants in the new PAGs.

  11. Heat-affected zone of metals ablated with femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Hirayama, Yoichi; Obara, Minoru

    2003-07-01

    The melted area is found on the surface ablated by nanosecond and picosecond laser pulses. However, the heat effect is little on the ablated surface in the case of femtosecond laser due to non-thermal ablation process. Heat-affected zone of metallic bulk crystal ablated with femtosecond Ti:sapphire laser pulses is experimentally studied. As a result of XRD (X-ray diffraction) measurements, the XRD peak signal of the area ablated with Ti:sapphire laser becomes smaller than that of the crystalline metal sample. While the crystallinity of the metal sample is crystalline before the laser ablation, the crystallinity in the ablated area is partially changed into the amorphous form. Because the residual pulse energy that is not used for the ablation process remains, leading to the formation of thin layer of melt phase. The melt layer is abruptly cooled down not to be re-crystallized, but to transform into the amorphous form. It is evident that the area ablated with femtosecond laser is changed into the amorphous metal. Additionally XRD measurements and AR+ etching are performed alternately to measure the thickness of the amorphous layer. In the case of iron, the thickness is measured to be 1 μm approximately, therefore heat-affected zone is quite small.

  12. Microstructure characterization of heat affected zone after welding in Mod.9Cr–1Mo steel

    SciTech Connect

    Sawada, K.; Hara, T.; Tabuchi, M.; Kimura, K.; Kubushiro, K.

    2015-03-15

    The microstructure of the heat affected zone after welding was investigated in Mod.9Cr–1Mo steel, using TEM and STEM-EDX. The microstructure of thin foil was observed at the fusion line, and at the positions of 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm and 3.5 mm to the base metal side of the fusion line. Martensite structure with very fine lath and high dislocation density was confirmed at all positions. Twins with a twin plane of (112) were locally observed at all positions. Elemental mapping was obtained for all positions by means of STEM-EDX. Inclusions of mainly Si were formed at the fusion line but not at the other positions. No precipitates could be detected at the fusion line or at the position of 0.5 mm. On the other hand, MX particles were observed at the positions of 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm and 3.5 mm even after welding. M{sub 23}C{sub 6} particles were also confirmed at the positions of 2.0 mm, 2.5 mm, 3.0 mm and 3.5 mm. Very fine equiaxed grains were locally observed at the positions of 2.0 mm and 2.5 mm. The Cr content of the equiaxed grains was about 12 mass%, although the martensite area included about 8 mass% Cr. - Graphical abstract: Display Omitted - Highlights: • Nonequilibrium microstructure of heat affected zone was observed after welding in Mod.9Cr–1Mo steel. • Inclusions containing Si were detected at the fusion line. • Undissolved M{sub 23}C{sub 6} and MX particles were confirmed in heat affected zone. • Twins with a twin plane of (112) were locally observed at all positions. • Very fine ferrite grains with high Cr content were observed in fine grained heat affected zone.

  13. Moessbauer analysis of heat affected zones of an SA 508 steel weld

    SciTech Connect

    Kwon, S.J.; Oh, S.J.; Kim, S.; Lee, S.; Kim, J.H.

    1998-12-18

    Microstructure of a heat affected zone (HAZ) in a weld is influenced by many factors such as chemical composition, welding condition, and peak temperature. It is more complex under multi-pass welding because of the repeated heat input. For the analysis of the HAZ microstructure, optical microscope, electron microscope, and X-ray diffraction techniques have been widely used. However, their application is limited since they can hardly make quantitative analysis of HAZ where numerous phases such as martensite, bainite, ferrite, pearlite, austenite, and carbides are co-existing. Moessbauer spectroscopy, in such a case, is particularly useful due to the capability of quantitative analysis on the fraction of each phase. In this study, phases present in the HAZ of an SA 508 steel were identified, and their fractions were quantitatively determined by Moessbauer spectroscopy in conjunction with microscopic observations.

  14. Characterization of microstructure, local deformation and microchemistry in Alloy 690 heat-affected zone and stress corrosion cracking in high temperature water

    NASA Astrophysics Data System (ADS)

    Lu, Zhanpeng; Chen, Junjie; Shoji, Tetsuo; Takeda, Yoichi; Yamazaki, Seiya

    2015-10-01

    With increasing the distance from the weld fusion line in an Alloy 690 heat-affected zone, micro-hardness decreases, kernel average misorientation decreases and the fraction of Σ3 boundaries increases. Chromium depletion at grain boundaries in the Alloy 690 heat-affected zone is less significant than that in an Alloy 600 heat-affected zone. Alloy 690 heat-affected zone exhibits much higher IGSCC resistance than Alloy 600 heat-affected zone in simulated pressurized water reactor primary water. Heavily cold worked Alloy 690 exhibits localized intergranular stress corrosion cracking. The effects of metallurgical and mechanical properties on stress corrosion cracking in Alloy 690 are discussed.

  15. Magnetic Barkhausen noise for reliable detection of the heat affected zone in welded ship steel plate

    NASA Astrophysics Data System (ADS)

    Blaow, Mohamed M.; Shaw, Brian A.

    2014-02-01

    The applicability of the Barkhausen noise technique to non-destructively determine the heat affected zone (HAZ) in welded steel plates was investigated. Magnetic Barkhausen noise measurements were conducted on welded hot-rolled low carbon ship steel plates to determine the MBN behaviour following the exposure to elevated heat in a localized region by welding. The exciting field was applied parallel to the weld bead. The results showed a variation in MBN level along a line that crosses the weld bead. The MBN intensity was higher in the near weld material compared with a lower intensity when the measurement setup was moved away from the weld bead in both sides of the weld. The increased MBN level was attributed to the induced residual tensile stresses as a result of the shrinkage of the hot zone. The variation of MBN along the measurement line was eliminated after the welded plate was shot peened. The decrease in MBN intensity after shot peening was attributed to the induced compressive stresses. The results were explained in terms of different mechanisms of interaction of domain walls with residual tensile and compressive stresses.

  16. TEM observation of the heat-affected zone in electron beam welded superalloy Inconel 713C

    SciTech Connect

    Lachowicz, Maciej Dudzinski, Wlodzimierz; Podrez-Radziszewska, Marzena

    2008-05-15

    The paper presents results of microstructural observations and phase analysis of electron-beam-welded fusion zones in superalloy Inconel 713C using transmission electron microscopy. In the fusion zone, a 90% fraction of fine-grained {gamma}' precipitates was found, with sizes up to 30 nm. No dislocations were observed in the precipitates or at the {gamma}-{gamma}' interface. Primary, undissolved inclusions of {gamma}' were found in the heat-affected zone (HAZ). In the HAZ, a very high concentration of dislocations was found at the {gamma}-{gamma}' boundaries, as well as inside the {gamma}' particles and in the {gamma} solid solution. The increased dislocation density indicates loss of coherence of that phase and the creation of a semi-coherent boundary, and is related to dissolution of the particles and intensified diffusion through the interphase {gamma}-{gamma}' boundary. The lattice misfit coefficient {delta}a/a between the {gamma}' particles and {gamma} solution in the HAZ indicates negative values from - 0.20% to - 0.06%. The presence of semi-coherent boundaries and the negative lattice misfit coefficient leads to dislocation locking and can result in cracking in the HAZ.

  17. A model for heat-affected zone hardness profiles in Al-Li-X alloys

    SciTech Connect

    Rading, G.O.; Berry, J.T.

    1998-09-01

    A model based on reaction kinetics and elemental diffusion is proposed to account for the presence of double inflection in the hardness profiles of the heat-affected zone (HAZ) in weldments of Al-Li-X alloys tested without postweld heat treatment (PWHT). Such profiles are particularly evident when (1) the base metal is in the peak-aged (T8 or T6) temper condition prior to welding; (2) the welding process is a high-heat input process, i.e., gas tungsten arc (GTA), gas metal arc (GMA) or plasma arc (PA) welding; and (3) a filler alloy deficient in lithium (i.e., AA 2319) is used. In the first part of this paper, the theoretical mechanisms are presented. It is proposed that the double inflection appears due to complete or partial reversion of the semi-coherent, plate-like precipitates (i.e., {theta}{prime}, T{sub 1} or S{prime}); coarsening of the plate-like precipitates at constant volume fraction; precipitation of {delta}{prime} as a result of natural aging; and diffusion of lithium from the HAZ into the weld pool due to the concentration gradient between the weld pool and the base metal. In the second part (to be published in next month`s Welding Journal), experimental validation of the model is provided using weldments of the Al-Li-Cu Alloy 2095.

  18. Prediction of laser cutting heat affected zone by extreme learning machine

    NASA Astrophysics Data System (ADS)

    Anicic, Obrad; Jović, Srđan; Skrijelj, Hivzo; Nedić, Bogdan

    2017-01-01

    Heat affected zone (HAZ) of the laser cutting process may be developed based on combination of different factors. In this investigation the HAZ forecasting, based on the different laser cutting parameters, was analyzed. The main goal was to predict the HAZ according to three inputs. The purpose of this research was to develop and apply the Extreme Learning Machine (ELM) to predict the HAZ. The ELM results were compared with genetic programming (GP) and artificial neural network (ANN). The reliability of the computational models were accessed based on simulation results and by using several statistical indicators. Based upon simulation results, it was demonstrated that ELM can be utilized effectively in applications of HAZ forecasting.

  19. Heat-affected zone in microdrilling of metals by femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Audouard, E.; LeHarzic, R.; Huot, Nicolas; Laporte, Pierre; Valette, S.; Fourtunier, R.

    2002-09-01

    Several works on laser-matter interaction has shown the differences in sizes for the Heat Affected Zone (HAZ) obtained with nanosecond and femtosecond regimes in laser cutting or drilling. To understand more clearly the basic phenomena that occur in femtosecond regime during the absorption of light by matter, and specially in the case of metals, we have developed both an experimental and a theoretical approach. We use a new method aimed at quantifying the dimensions of the HAZ, using thin-down samples which are micro-drilled and then observed by a transmission electronic microscopy (TEM) technique. The grain size in the samples is analysed near the micro-holes. According to theoretical studies, the thermal diffusion is due to the smaller value of the electron specific heat compared to the lattice one. The thermal diffusion length is found to be a few hundred of nanometers in the case of metals. We use a thermal model to describe the heat diffusion in the sample in order to obtain a theoretical estimation of the HAZ. Holes are drilled in Aluminum using nanosecond and femtosecond laser pulses and characterized by Transmission Electronic Microscopy (TEM). The method for quantifying the dimensions of the heat affected zone (HAZ) surrounding micro-holes is based on the analyze of the grain size evolution. The experiments are using the same Ti-Sapphire laser source (1 kHz, 800 nm). The regeneratively amplified ultra-short pulses (150 fs) are utilized at a low fluence regime (typically 0.01-0.5 mJ/pulse), while the longer pulses (ns) are obtained from the regenerative amplifier without oscillator seeding (0.5 mJ,τ approximately 7-8 ns). The main conclusion is that a 40 micrometers wide HAZ is induced by nanosecond pulses, whereas the femtosecond regime does not produce any TEM observable HAZ. It has to be noticed that the width of the femtosecond HAZ is roughly less than 2 micrometers , which is our observation limit. These results are in agreement with theoretical

  20. Visualization of Microstructural Factor Resisting the Cleavage-Crack Propagation in the Simulated Heat-Affected Zone of Bainitic Steel

    NASA Astrophysics Data System (ADS)

    Terasaki, Hidenori; Miyahara, Yu; Ohata, Mitsuru; Moriguchi, Koji; Tomio, Yusaku; Hayashi, Kotaro

    2015-12-01

    Cleavage-crack propagation behavior was investigated in the simulated coarse-grained heat-affected zone (CGHAZ) of bainitic steel using electron backscattering diffraction (EBSD) pattern analysis when a low heat input welding was simulated. From viewpoint of crystallographic analysis, it was the condition in which the Bain zone was smaller than the close-packed plane (CP) group. It was clarified that the Bain zone and CP group boundaries provided crack-propagation resistance. The results revealed that when the Bain zone was smaller than the CP group, crack length was about one quarter the size of that measured when the CP group was smaller than the Bain zone because of the increasing Bain-zone boundaries. Furthermore, it was clarified that the plastic work associated with crack opening and resistance at the Bain and CP boundaries could be visualized by the kernel average misorientation maps.

  1. Simulation of the weld heat affected zone of a 0.5Cr-Mo-V steel

    SciTech Connect

    Radhakrishnan, B.; Zacharia, T.

    1995-12-01

    By using a Monte Carlo grain growth algorithm and a methodology for obtaining a one-to-one correlation between Monte Carlo and real parameters of grain size and time, the grain structure in the weld heat affected zone of a 0.5 Mo-Cr-V steel has been simulated. The simulations clearly show that the kinetics of grain growth can be retarded by the presence of steep temperature gradients in the weld heat affected zone. Additional pinning, due to the formation of grain boundary liquid near the solidus temperature, has also been simulated. It is shown that in order to accurately predict the observed grain size in the weld heat affected zone of the 0.5Cr-Mo-V steel, the retardation in growth kinetics due to temperature gradients as well as liquid pinning should be considered.

  2. Crack growth rates of irradiated austenitic stainless steel weld heat affected zone in BWR environments.

    SciTech Connect

    Chopra, O. K.; Alexandreanu, B.; Gruber, E. E.; Daum, R. S.; Shack, W. J.; Energy Technology

    2006-01-31

    Austenitic stainless steels (SSs) are used extensively as structural alloys in the internal components of reactor pressure vessels because of their superior fracture toughness. However, exposure to high levels of neutron irradiation for extended periods can exacerbate the corrosion fatigue and stress corrosion cracking (SCC) behavior of these steels by affecting the material microchemistry, material microstructure, and water chemistry. Experimental data are presented on crack growth rates of the heat affected zone (HAZ) in Types 304L and 304 SS weld specimens before and after they were irradiated to a fluence of 5.0 x 10{sup 20} n/cm{sup 2} (E > 1 MeV) ({approx} 0.75 dpa) at {approx}288 C. Crack growth tests were conducted under cycling loading and long hold time trapezoidal loading in simulated boiling water reactor environments on Type 304L SS HAZ of the H5 weld from the Grand Gulf reactor core shroud and on Type 304 SS HAZ of a laboratory-prepared weld. The effects of material composition, irradiation, and water chemistry on growth rates are discussed.

  3. Initial Evaluation of the Heat-Affected Zone, Local Embrittlement Phenomenon as it Applies to Nuclear Reactor Vessels

    SciTech Connect

    McCabe, D.E.

    1999-09-01

    The objective of this project was to determine if the local brittle zone (LBZ) problem, encountered in the testing of the heat-affected zone (HAZ) part of welds in offshore platform construction, can also be found in reactor pressure vessel (RPV) welds. Both structures have multipass welds and grain coarsening along the fusion line. Literature was obtained that described the metallurgical evidence and the type of research work performed on offshore structure welds.

  4. Evaluation of Heat-affected Zone Hydrogen-induced Cracking in High-strength Steels

    NASA Astrophysics Data System (ADS)

    Yue, Xin

    Shipbuilding is heavily reliant on welding as a primary fabrication technique. Any high performance naval steel must also possess good weldability. It is therefore of great practical importance to conduct weldability testing of naval steels. Among various weldability issues of high-strength steels, hydrogen-induced cracking (HIC) in the heat-affected zone (HAZ) following welding is one of the biggest concerns. As a result, in the present work, research was conducted to study the HAZ HIC susceptibility of several naval steels. Since the coarse-grained heat-affected zone (CGHAZ) is generally known to be the most susceptible to HIC in the HAZ region, the continuous cooling transformation (CCT) behavior of the CGHAZ of naval steels HSLA-65, HSLA-100, and HY-100 was investigated. The CGHAZ microstructure over a range of cooling rates was characterized, and corresponding CCT diagrams were constructed. It was found that depending on the cooling rate, martensite, bainite, ferrite and pearlite can form in the CGHAZ of HSLA-65. For HSLA-100 and HY-100, only martensite and bainite formed over the range of cooling rates that were simulated. The constructed CCT diagrams can be used as a reference to select welding parameters to avoid the formation of high-hardness martensite in the CGHAZ, in order to ensure resistance to hydrogen-induced cracking. Implant testing was conducted on the naval steels to evaluate their susceptibility to HAZ HIC. Stress vs. time to failure curves were plotted, and the lower critical stress (LCS), normalized critical stress ratio (NCSR) and embrittlement index (EI) for each steel were determined, which were used to quantitatively compare HIC susceptibility. The CGHAZ microstructure of the naval steels was characterized, and the HIC fracture behavior was studied. Intergranular (IG), quasi-cleavage (QC) and microvoid coalescence (MVC) fracture modes were found to occur in sequence during the crack initiation and propagation process. This was

  5. Antimony-induced embrittlement in welding heat-affected zones in a Cr-Mo low-alloy steel

    NASA Astrophysics Data System (ADS)

    Zheng, L.; Song, S.-H.

    2013-07-01

    Heat-affected zones (HAZs) were simulated with a peak temperature of 1320 °C at different welding heat inputs for a Cr-Mo low-alloy steel. The ductile-to-brittle transition temperature (DBTT) of the HAZs increased with increasing heat input. When 0.05 wt.% Sb was added to the steel, the DBTTs of the HAZs became 1 and 10 °C higher than those for the undoped steel at heat inputs of 36 and 60 kJ/cm, respectively. Sb segregation to austenite grain boundaries during thermal cycling was found to be mainly responsible for the DBTT increase.

  6. Fundamental Studies of Phase Transformations and Mechanical Properties in the Heat Affected Zone of 10 wt% Nickel Steel

    NASA Astrophysics Data System (ADS)

    Barrick, Erin J.

    United States naval applications require the use of steels with high strength and resistance to fracture at low temperatures to provide good ballistic properties. In recent years, 10 wt% Ni steel has been developed with strength and toughness values exceeding those of steels currently used, and is now being considered as a candidate material to replace existing high-strength, low alloy steels. This steel has excellent toughness from the mechanically induced transformation of interlath austenite films to martensite. These austenite films are formed via a carefully developed quenching, lamellarizing, and tempering heat treatment. However, before 10 wt% Ni steel can be implemented for full-scale applications, the effects of the rapid heating and cooling rates associated with welding thermal cycles on phase transformations and mechanical properties must be understood. In this research, a fundamental understanding of phase transformations and mechanical properties in the heat-affected zone of fusion welds in 10 wt% Ni steel was developed through heating and cooling rate dilatometry experiments, gas tungsten arc welding, and simulation of gas metal arc welding. First, an investigation into the effects of heating and cooling rate on the phase transformations in 10 wt% Ni steel was performed. The Ac1 and Ac3 temperatures during heating were determined as a function of heating rate, and sluggish transformation during fast heating rates manifested itself as a high Ac3 temperature of 1050°C as opposed to a temperature of 850°C at slow heating rates. A continuous cooling transformation diagram produced for 10 wt% Ni steel reveals that martensite will form over a very wide range of cooling rates, which reflects a very high hardenability of this alloy. This is significant because the range of cooling rates for which the diagram was constructed over easily covers the range associated with fusion welding, so there would not be the need for precise control over the weld

  7. An investigation of reheat cracking in the weld heat affected zone of type 347 stainless steel

    NASA Astrophysics Data System (ADS)

    Phung-On, Isaratat

    2007-12-01

    microvoid corresponds to the size of precipitate that forms. In addition, there was intragranular cracking in some location indicating that another failure mechanism may also be possible. It was believed that failure may occur along a precipitate free zone. However, the distinct PFZ could not be detected. A SS-DTA technique was also implemented in order to determine precipitation temperatures of the material. The results showed the possible precipitation temperatures in the range of 850°C to 650°C. However, the results were not confidently reliable due to the small amount of carbide formed that affects the sensitivity of the SS-DTA. A simple grain boundary sliding model was generated proposing that the sliding is operated by the shear stress resulting from the formation of precipitate in the grain interior. Then, the sliding results in the microvoid formation and coalescence followed by cracking. In addition, a simple finite element model was generated to provide the illustration of the shear stress built up by the formation of precipitate. The model showed that shear stress can cause the grain boundary movement/sliding. Based on the results from this study, the recommendation for the selection of post weld heat treatment schedule as well as welding procedures can be determined for the prevention of the reheat cracking. A residual stress should be kept below the critical value during welding and post weld heat treating. The testing procedures used in this study can be applied as the guidelines to conduct the reheat cracking susceptibility test for material selection.

  8. Calibrated heat flow model for the determination of different heat-affected zones in single-pass laser-cut CFRP using a cw CO2 laser

    NASA Astrophysics Data System (ADS)

    Mucha, P.; Berger, P.; Weber, R.; Speker, N.; Sommer, B.; Graf, T.

    2015-03-01

    Laser machining has great potential for automated manufacturing of parts made of carbon-fiber-reinforced plastic (CFRP) due to the nearly force and tool-wear free processing. The high vaporization temperatures and the large heat conductivity of the carbon fibers, however, lead to unintentional heat conduction into the material causing damage in zones close to the process. In this paper, the matrix damage zone (MDZ) is subdivided into a matrix sublimation zone (MSZ) where the matrix material was sublimated and a zone where the temperature temporarily exceeded a value causing structural damage in the matrix. In order to investigate the extent of these zones, a one-dimensional heat flow model was applied, which was calibrated by cutting experiments using temperature sensors embedded in the CFRP samples. The investigations showed that the extents of the MSZ and MDZ are dominated by a total interaction time, which includes the passage of the laser beam and the continued interaction of the cloud of hot ablation products with the carbon fibers at the kerf wall and that from a practical point of view, the experimentally determined effective heat conductivity is suitable for simple estimations of the heat-affected zones in CFRP.

  9. Inverse Thermal Analysis of Ti-6Al-4V Laser Welds Using Solidification and Heat-Affected Zone Boundaries

    NASA Astrophysics Data System (ADS)

    Lambrakos, S. G.

    2017-03-01

    Temperature histories of Ti-6Al-4V laser welds are presented, which are calculated using numerical-analytical basis functions and boundary constraints based on measured solidification and heat-affected zone cross sections. These weld temperature histories can be adopted as input data to various types of computational procedures, which include numerical models for prediction of solid-state phase transformations and mechanical response. In addition, these temperature histories can be used parametrically for inverse thermal analysis of welds corresponding to other welding processes whose process conditions are within similar regimes. The present study applies an inverse thermal analysis procedure that uses three-dimensional constraint conditions whose two-dimensional projections are mapped within transverse cross sections of experimentally measured solidification and heat-affected zone boundaries.

  10. Inverse Thermal Analysis of Ti-6Al-4V Laser Welds Using Solidification and Heat-Affected Zone Boundaries

    NASA Astrophysics Data System (ADS)

    Lambrakos, S. G.

    2017-02-01

    Temperature histories of Ti-6Al-4V laser welds are presented, which are calculated using numerical-analytical basis functions and boundary constraints based on measured solidification and heat-affected zone cross sections. These weld temperature histories can be adopted as input data to various types of computational procedures, which include numerical models for prediction of solid-state phase transformations and mechanical response. In addition, these temperature histories can be used parametrically for inverse thermal analysis of welds corresponding to other welding processes whose process conditions are within similar regimes. The present study applies an inverse thermal analysis procedure that uses three-dimensional constraint conditions whose two-dimensional projections are mapped within transverse cross sections of experimentally measured solidification and heat-affected zone boundaries.

  11. Prediction of the Properties of Heat-Affected Zone of Welded Joints of Sheets from Aluminum Alloys with Structured Surface

    NASA Astrophysics Data System (ADS)

    Mikhailov, V. G.

    2016-05-01

    Welded joints of light structured sheets from aluminum alloy EN AW-6181-T4 (DIN EN 515) of the Al - Si - Mg system are studied. The welding is performed in an argon environment with a short arc by the method of cold metal transfer (CMT®). The results of the study are used in an amended Leblond model for describing the variation of the properties of the heat-affected zone of welded joints of structured sheets.

  12. Numerical simulation of friction stir welding (FSW): Prediction of the heat affect zone using a softening model

    NASA Astrophysics Data System (ADS)

    Paulo, R. M. F.; Carlone, P.; Valente, R. A. F.; Teixeira-Dias, F.; Palazzo, G. S.

    2016-10-01

    In this work a numerical model is proposed to simulate Friction Stir Welding (FSW) process in AA2024-T3 plates. This model included a softening model that account for the temperature history and the hardness distribution on a welded plate can thus be predicted. The validation of the model was performed using experimental measurements of the hardness in the plate cross-section. There is an acceptable prediction of the material softening in the Heat Affected Zone (HAZ) using the adopted model.

  13. Characterization of hole circularity and heat affected zone in pulsed CO2 laser drilling of alumina ceramics

    NASA Astrophysics Data System (ADS)

    Bharatish, A.; Narasimha Murthy, H. N.; Anand, B.; Madhusoodana, C. D.; Praveena, G. S.; Krishna, M.

    2013-12-01

    Circularity of drilled hole at the entry and exit, heat affected zone and taper are important attributes which influence the quality of a drilled hole in laser drilling. This paper examines the effect of laser parameters on the quality of drilled holes in Alumina ceramics which are widely used in microelectronic devices, based on orthogonal array experimentation and response surface methodology. Both entrance and exit circularities were significantly influenced by hole diameter and laser power. Heat affected zone was influenced by frequency. Taper was also significantly influenced by laser power. Response surface model predicted nominal entrance circularity at 2.5 kHz, 240 W, 2.5 mm/s, 1 mm hole, exit circularity and taper at 7.5 kHz, 240 W, 4.5 mm/s, and 1 mm hole. The model predicted lowest heat affected zone at 7.5 kHz, 240 W, 2.5 mm/s, and 1 mm. Multiobjective optimization achieved using both response surface model and gray relational analysis indicated that all the four quality parameters are optimized at 7.5 kHz, 240 W, 3.85 mm/s and 1 mm.

  14. The study on microstructural and mechanical properties of weld heat affected zone of 7075-T651 aluminum alloy

    SciTech Connect

    Hwang, R.Y.; Chou, C.P.

    1997-12-22

    Aluminum alloys play an important role in aerospace industry due to their high strength and low density. The general accepted precipitation behavior of 7075 alloy was represented as: supersaturated solid solution {alpha}{sub ss} {yields} Gp zones {yields} {eta}{prime}(MgZn{sub 2}) {yields} {eta}(MgZn{sub 2}). The Addition of Cu in Al-Zn-Mg alloy would promote the transformation of GP zones into {eta}{prime}(MgZn{sub 2}) phase and stabilize the {eta}(MgZn{sub 2}) phase. The T6 temper has the maximum strength but lower ductility. The T73 temper may lose some strength, but can gain higher corrosion resistance and lower susceptibility to stress corrosion cracking as compared to the T6 temper. The welding fabrication can produce thermal cycling on the weldment. In the heat affected zone (HAZ) beside the fusion zone, different temperatures can be obtained. This would cause change of microstructure in the HAZ of aluminum alloy weldment. Many workers studied the behavior of weld HAZ by cutting the HAZ into many small pieces or using short time isothermal heat treatment to simulate the HAZ. This may lose some information, especially near the fusion zone, because high temperature gradient occurred in this region. In this study, the Gleeble system was used to simulate the weld HAZ. It can accurately simulate every point of weld HAZ by heating and cooling the specimen to the thermal history of weld HAZ as the same as measured. The microstructural and mechanical properties of weld HAZ of 7075-T651 alloy were investigated.

  15. Neural Network approach to assess the thermal affected zone around the injection well in a groundwater heat pump system

    NASA Astrophysics Data System (ADS)

    Lo Russo, Stefano; Taddia, Glenda; Verda, Vittorio

    2014-05-01

    The common use of well doublets for groundwater-sourced heating or cooling results in a thermal plume of colder or warmer re-injected groundwater known as the Thermal Affected Zone(TAZ). The plumes may be regarded either as a potential anthropogenic geothermal resource or as pollution, depending on downstream aquifer usage. A fundamental aspect in groundwater heat pump (GWHP) plant design is the correct evaluation of the thermally affected zone that develops around the injection well. Temperature anomalies are detected through numerical methods. Crucial elements in the process of thermal impact assessment are the sizes of installations, their position, the heating/cooling load of the building, and the temperature drop/increase imposed on the re-injected water flow. For multiple-well schemes, heterogeneous aquifers, or variable heating and cooling loads, numerical models that simulate groundwater and heat transport are needed. These tools should consider numerous scenarios obtained considering different heating/cooling loads, positions, and operating modes. Computational fluid dynamic (CFD) models are widely used in this field because they offer the opportunity to calculate the time evolution of the thermal plume produced by a heat pump, depending on the characteristics of the subsurface and the heat pump. Nevertheless, these models require large computational efforts, and therefore their use may be limited to a reasonable number of scenarios. Neural networks could represent an alternative to CFD for assessing the TAZ under different scenarios referring to a specific site. The use of neural networks is proposed to determine the time evolution of the groundwater temperature downstream of an installation as a function of the possible utilization profiles of the heat pump. The main advantage of neural network modeling is the possibility of evaluating a large number of scenarios in a very short time, which is very useful for the preliminary analysis of future multiple

  16. Microstructures relevant to brittle fracture initiation at the heat-affected zone of weldment of a low carbon steel

    SciTech Connect

    Ohya, K.; Kim, J.; Yokoyama, K.; Nagumo, M.

    1996-09-01

    Charpy toughness of the heat-affected zone (HAZ) of weldment of a low carbon steel has been investigated by means of an instrumented Charpy test and fractographic analysis. Microstructures were varied with thermal cycles simulating double-pass welding. The ductile-brittle transition temperature is the most deteriorated at an intermediate second-cycle heating temperature. The origin of the difference in the transition temperatures has been analyzed to exist in the brittle fracture initiation stage. Fractographic examination correlating with microstructural features has revealed that the brittle fracture initiation site is associated with the intersection of bainitic ferrite areas with different orientations rather than the martensite-austenite constituents. The role of the constraint of plastic deformation on the brittle fracture initiation is discussed.

  17. Corrosion behavior in high heat input welded heat-affected zone of Ni-free high-nitrogen Fe–18Cr–10Mn–N austenitic stainless steel

    SciTech Connect

    Moon, Joonoh Ha, Heon-Young; Lee, Tae-Ho

    2013-08-15

    The pitting corrosion and interphase corrosion behaviors in high heat input welded heat-affected zone (HAZ) of a metastable high-nitrogen Fe–18Cr–10Mn–N austenitic stainless steel were explored through electrochemical tests. The HAZs were simulated using Gleeble simulator with high heat input welding condition of 300 kJ/cm and the peak temperature of the HAZs was changed from 1200 °C to 1350 °C, aiming to examine the effect of δ-ferrite formation on corrosion behavior. The electrochemical test results show that both pitting corrosion resistance and interphase corrosion resistance were seriously deteriorated by δ-ferrite formation in the HAZ and their aspects were different with increasing δ-ferrite fraction. The pitting corrosion resistance was decreased by the formation of Cr-depleted zone along δ-ferrite/austenite (γ) interphase resulting from δ-ferrite formation; however it didn't depend on δ-ferrite fraction. The interphase corrosion resistance depends on the total amount of Cr-depleted zone as well as ferrite area and thus continuously decreased with increasing δ-ferrite fraction. The different effects of δ-ferrite fraction on pitting corrosion and interphase corrosion were carefully discussed in terms of alloying elements partitioning in the HAZ based on thermodynamic consideration. - Highlights: • Corrosion behavior in the weld HAZ of high-nitrogen austenitic alloy was studied. • Cr{sub 2}N particle was not precipitated in high heat input welded HAZ of tested alloy. • Pitting corrosion and interphase corrosion show a different behavior. • Pitting corrosion resistance was affected by whether or not δ-ferrite forms. • Interphase corrosion resistance was affected by the total amount of δ-ferrite.

  18. Heat-Affected Zone Liquation Cracking Resistance of Friction Stir Processed Aluminum-Copper Alloy AA 2219

    NASA Astrophysics Data System (ADS)

    Karthik, G. M.; Janaki Ram, G. D.; Kottada, Ravi Sankar

    2016-12-01

    In the current work, the effect of friction stir processing on heat-affected zone (HAZ) liquation cracking resistance of aluminum-copper alloy AA 2219 was evaluated. In Gleeble hot-ductility tests and longitudinal Varestraint tests, the FSPed material, despite its very fine dynamically recrystallized equiaxed grain structure, showed considerably higher susceptibility to HAZ liquation cracking when compared to the base material. Detailed microstructural studies showed that the increased cracking susceptibility of the FSPed material is due to (i) increase in the amount of liquating θ phase (equilibrium Al2Cu) and (ii) increase in the population of grain boundary θ particles. An important learning from the current work is that, in certain materials like alloy 2219, the use of FSP as a pretreatment to fusion welding can be counterproductive.

  19. Heat-Affected Zone Liquation Cracking Resistance of Friction Stir Processed Aluminum-Copper Alloy AA 2219

    NASA Astrophysics Data System (ADS)

    Karthik, G. M.; Janaki Ram, G. D.; Kottada, Ravi Sankar

    2017-04-01

    In the current work, the effect of friction stir processing on heat-affected zone (HAZ) liquation cracking resistance of aluminum-copper alloy AA 2219 was evaluated. In Gleeble hot-ductility tests and longitudinal Varestraint tests, the FSPed material, despite its very fine dynamically recrystallized equiaxed grain structure, showed considerably higher susceptibility to HAZ liquation cracking when compared to the base material. Detailed microstructural studies showed that the increased cracking susceptibility of the FSPed material is due to (i) increase in the amount of liquating θ phase (equilibrium Al2Cu) and (ii) increase in the population of grain boundary θ particles. An important learning from the current work is that, in certain materials like alloy 2219, the use of FSP as a pretreatment to fusion welding can be counterproductive.

  20. Correlation of the microstructure and fracture toughness of the heat-affected zones of an SA 508 steel

    SciTech Connect

    Kim, S.; Kang, S.Y.; Oh, S.J.; Kwon, S.J.; Lee, S.; Kim, J.H.; Hong, J.H.

    2000-04-01

    In this study, microstructures of a heat-affected zone (HAZ) of an SA 508 steel were identified by Moessbauer spectroscopy in conjunction with microscopic observations, and were correlated with fracture toughness. Specimens with the peak temperature raised to 1350 C showed mostly martensite. With the peak temperature raised to 900 C, the martensite fraction was reduced, while bainite or martensite islands were formed because of the slow cooling from the lower austenite region and the increase in the prior austenite grain size. As the martensite fraction present inside the HAZ increased, hardness and strength tended to increase, whereas fracture toughness decreased. The microstructures were not changed much from the base metal because of the minor tempering effect when it was raised to 650 C or 700 C. However, fracture toughness of the subcritical HAZ with the peak temperature raised to 650 C to 700 C was seriously reduced after postweld heat treatment (PWHT) because carbide particles were of primary importance in initiating voids. Thus, the most important microstructural factors affecting fracture toughness were the martensite fraction before PWHT and the carbide fraction after PWHT.

  1. Hot-cracking studies of Inconel 718 weld- heat-affected zones

    NASA Technical Reports Server (NTRS)

    Thompson, E. G.

    1969-01-01

    Hot ductility tests, gas-tungsten-arc fillerless fusion tests, and circle patch-weld-restraint tests were conducted on Inconel 718 to better understand and correlate the weldability /resistance to hot cracking/ of the alloy. A correlation of the test results with composition, heat-treat condition, grain size, and microstructure was made.

  2. A process model for the heat-affected zone microstructure evolution in duplex stainless steel weldments: Part I. the model

    NASA Astrophysics Data System (ADS)

    Hemmer, H.; Grong, Ø.

    1999-11-01

    The present investigation is concerned with modeling of the microstructure evolution in duplex stainless steels under thermal conditions applicable to welding. The important reactions that have been modeled are the dissolution of austenite during heating, subsequent grain growth in the delta ferrite regime, and finally, the decomposition of the delta ferrite to austenite during cooling. As a starting point, a differential formulation of the underlying diffusion problem is presented, based on the internal-state variable approach. These solutions are later manipulated and expressed in terms of the Scheil integral in the cases where the evolution equation is separable or can be made separable by a simple change of variables. The models have then been applied to describe the heat-affected zone microstructure evolution during both thick-plate and thin-plate welding of three commercial duplex stainless steel grades: 2205, 2304, and 2507. The results may conveniently be presented in the form of novel process diagrams, which display contours of constant delta ferrite grain size along with information about dissolution and reprecipitation of austenite for different combinations of weld input energy and peak temperature. These diagrams are well suited for quantitative readings and illustrate, in a condensed manner, the competition between the different variables that lead to structural changes during welding of duplex stainless steels.

  3. The effect of cooling speed on the structure and properties of the heat affected zone in welded compounds of ferrite-austenitic steels

    NASA Astrophysics Data System (ADS)

    Gonik, I. L.; Gurulev, D. N.; Bondareva, O. P.

    2017-02-01

    Such parameters as the maximum heating temperature, duration of stay at high temperatures, the rate of cooling influence greatly the structure and properties of the heat-affected zone of welded joints of steels and alloys. In the present work, the effect of different cooling speed upon the impact of the thermal cycle of welding on the structure, the fine structure and toughness of ferrite-austenitic steels is investigated. It is established that the cooling speed after welding has a great influence on the shock impact toughness, the phase composition and the structure of the zone of ferrite-austenitic steels.

  4. Evaluation of Crack Arrest Fracture Toughness of Parent Plate, Weld Metal and Heat Affected Zone of BIS 812 EMA Ship Plate Steel

    DTIC Science & Technology

    1993-10-01

    34- EVALUATION OF CRACK ARREST FRACTURE TOUGHNESS OF PARENT PLATE, WELD METAL 0 AND HEAT AFFECTED ZONE OF BIS 812 EMA SHIP PLATE STEEL IA BURCH MRL-TR...had a deleterious effect on the crack arrest properties of this particular steel . Tests on each of these regions revealed that, far the combination of...fracture toughness assessment is not a requirement for qualification for this steel , crack arrest fracture toughness, Kj, can be used to • 0 characterise the

  5. The Effect of Substrate Microstructure on the Heat-Affected Zone Size in Sn-Zn Alloys Due to Adjoining Ni-Al Reactive Multilayer Foil Reaction

    DOE PAGES

    Hooper, R. J.; Adams, D. P.; Hirschfeld, D.; ...

    2015-08-05

    The rapid release of energy from reactive multilayer foils can create extreme local temperature gradients near substrate materials. To fully exploit the potential of these materials, a better understanding of the interaction between the substrate or filler material and the foil is needed. In particular, this work investigates how variations in local properties within the substrate (i.e. differences between properties in constituent phases) can affect heat transport into the substrate. Furthermore, this can affect the microstructural evolution observed within the substrate, which may affect the final joint properties. The effect of the initial substrate microstructure on microstructural evolution within themore » heat-affected zone is evaluated experimentally in two Sn-Zn alloys and numerical techniques are utilized to inform the analysis.« less

  6. The Effect of Substrate Microstructure on the Heat-Affected Zone Size in Sn-Zn Alloys Due to Adjoining Ni-Al Reactive Multilayer Foil Reaction

    SciTech Connect

    Hooper, R. J.; Adams, D. P.; Hirschfeld, D.; Manuel, M. V.

    2015-08-05

    The rapid release of energy from reactive multilayer foils can create extreme local temperature gradients near substrate materials. To fully exploit the potential of these materials, a better understanding of the interaction between the substrate or filler material and the foil is needed. In particular, this work investigates how variations in local properties within the substrate (i.e. differences between properties in constituent phases) can affect heat transport into the substrate. Furthermore, this can affect the microstructural evolution observed within the substrate, which may affect the final joint properties. The effect of the initial substrate microstructure on microstructural evolution within the heat-affected zone is evaluated experimentally in two Sn-Zn alloys and numerical techniques are utilized to inform the analysis.

  7. Effect of long-term aging on microstructure and local behavior in the heat-affected zone of a Ni–Cr–Mo–V steel welded joint

    SciTech Connect

    Zhu, Ming-Liang Wang, De-Qiang; Xuan, Fu-Zhen

    2014-01-15

    Evolution of microstructure, micro-hardness and micro-tensile strength behavior was investigated in the heat-affected zone of a Ni–Cr–Mo–V steel welded joint after the artificial aging at 350 °C for 3000 h. After detailed characterization of microstructures in optical microscopy, scanning electron microscopy and transmission electron microscopy, it is revealed that the change of martensite–bainite constituent promotes more homogeneous microstructure distribution. The aging treatment facilitates redistribution of carbon and chromium elements along the welded joint, and the micro-hardness is increased slightly through the welds due to enrichment of carbon. The types of precipitates in the weldment mainly include M{sub 3}C, MC, M{sub 2}C and M{sub 23}C{sub 6}. The carbides in base metal, weld metal and coarse-grained heat-affected zone are prone to change from ellipsoidal to platelet form whereas more uniform spherical carbides are observed in the fine-grained zone. Precipitation and coarsening of M{sub 23}C{sub 6} near the fusion line, and formation of MC and M{sub 2}C, are responsible for the tensile strength decrease and its smooth distribution in the aged heat-affected zone. This implies that the thermal aging can relieve strength mismatch in the weldments. - Highlights: • Microstructure homogeneity improved in HAZ after long-term aging. • Tensile strength decreased in HAZ due to precipitation and coarsening of M{sub 23}C{sub 6}. • Strength mismatch in NiCrMoV steel welds was relieved after aging at 350 °C × 3000 h.

  8. Evaluation of crack arrest fracture toughness of parent plate, weld metal and heat affected zone of BIS 812 EMA ship plate steel

    NASA Astrophysics Data System (ADS)

    Burch, I. A.

    1993-10-01

    The steel chosen for the pressure hull of the Collins class submarine has undergone evaluation to compare the crack arrest fracture toughness, K(Ia), of the parent plate with that of weld metal and heat affected zone. The tests were conducted over a range of subzero temperatures on specimens slightly outside the ASTM standard test method specimen configuration. Shallow face grooved specimens were used to vary the propagating crack velocity from that of non face grooved specimens and determine if K(Ia), is sensitive to changes in crack velocity. The weld metal, heat affected zone (HAZ), and parent plate were assessed to determine if the welding process had a deleterious effect on the crack arrest properties of this particular steel. Tests on each of these regions revealed that, for the combination of parent plate, welding procedure and consumables, no adverse effect on crack arrest properties was encountered. Crack arrest fracture toughness of the weld metal and HAZ was superior to that of the parent plate at comparable temperatures.

  9. Prediction and characterization of heat-affected zone formation in tin-bismuth alloys due to nickel-aluminum multilayer foil reaction

    SciTech Connect

    Hooper, R. J.; Davis, C. G.; Johns, P. M.; Adams, D. P.; Hirschfeld, D.; Nino, J. C.; Manuel, M. V.

    2015-06-26

    Reactive multilayer foils have the potential to be used as local high intensity heat sources for a variety of applications. In this study, most of the past research effort concerning these materials have focused on understanding the structure-property relationships of the foils that govern the energy released during a reaction. To improve the ability of researchers to more rapidly develop technologies based on reactive multilayer foils, a deeper and more predictive understanding of the relationship between the heat released from the foil and microstructural evolution in the neighboring materials is needed. This work describes the development of a numerical model for the purpose of predicting heat affected zone size in substrate materials. The model is experimentally validated using a commercially available Ni-Al multilayer foils and alloys from the Sn-Bi binary system. To accomplish this, phenomenological models for predicting the variation of physical properties (i.e., thermal conductivity, density, and heat capacity) with temperature and composition in the Sn-Bi system were utilized using literature data.

  10. Prediction and characterization of heat-affected zone formation in tin-bismuth alloys due to nickel-aluminum multilayer foil reaction

    DOE PAGES

    Hooper, R. J.; Davis, C. G.; Johns, P. M.; ...

    2015-06-26

    Reactive multilayer foils have the potential to be used as local high intensity heat sources for a variety of applications. In this study, most of the past research effort concerning these materials have focused on understanding the structure-property relationships of the foils that govern the energy released during a reaction. To improve the ability of researchers to more rapidly develop technologies based on reactive multilayer foils, a deeper and more predictive understanding of the relationship between the heat released from the foil and microstructural evolution in the neighboring materials is needed. This work describes the development of a numerical modelmore » for the purpose of predicting heat affected zone size in substrate materials. The model is experimentally validated using a commercially available Ni-Al multilayer foils and alloys from the Sn-Bi binary system. To accomplish this, phenomenological models for predicting the variation of physical properties (i.e., thermal conductivity, density, and heat capacity) with temperature and composition in the Sn-Bi system were utilized using literature data.« less

  11. Effect of welding conditions on transformation and properties of heat-affected zones in LWR (light-water reactor) vessel steels

    SciTech Connect

    Lundin, C.D.; Mohammed, S. . Welding Research and Engineering)

    1990-11-01

    The continuous cooling transformation behavior (CCT) and isothermal transformation (IT) behavior were determined for SA-508 and SA-533 materials for conditions pertaining to standard heat treatment and for the coarse-grained region of the heat-affected zone (HAZ). The resulting diagrams help to select welding conditions that produce the most favorable microconstituent for the development of optimum postweld heat treatment (PWHT) toughness levels. In the case of SA-508 and SA-533, martensite responds more favorably to PWHT than does bainite. Bainite is to be avoided for the optimum toughness characteristics of the HAZ. The reheat cracking tendency for both steels was evaluated by metallographic studies of simulated HAZ structures subjected to PWHT cycles and simultaneous restraint. Both SA-533, Grade B, Class 1, and SA-508, Class 2, cracked intergranularly. The stress rupture parameter (the product of the stress for a rupture life of 10 min and the corresponding reduction of area) calculated for both steels showed that SA-508, Class 2, was more susceptible to reheat cracking than SA-533, Grade B, Class 1. Cold cracking tests (Battelle Test and University of Tennessee modified hydrogen susceptibility test) indicated that a higher preheat temperature is required for SA-508, Class 2, to avoid cracking than is required for SA-533, Grade B, Class 1. Further, the Hydrogen Susceptibility Test showed that SA-508, Class 2, is more susceptible to hydrogen embrittlement than is SA-533, Grade B, Class 1.

  12. Effects of alloying elements on mechanical and fracture properties of base metals and simulated heat-affected zones of SA 508 steels

    NASA Astrophysics Data System (ADS)

    Kim, Sangho; Lee, Sunghak; Im, Young-Roc; Lee, Hu-Chul; Oh, Yong Jun; Hong, Jun Hwa

    2001-04-01

    This study was aimed at developing low-alloy steels for nuclear reactor pressure vessels by investigating the effects of alloying elements on mechanical and fracture properties of base metals and heat-affected zones (HAZs). Four steels whose compositions were variations of the composition specification for SA 508 steel (class 3) were fabricated by vacuum-induction melting and heat treatment, and their tensile properties and Charpy impact toughness were evaluated. Microstructural analyses indicated that coarse M3C-type carbides and fine M2C-type carbides were precipitated along lath boundaries and inside laths, respectively. In the steels having decreased carbon content and increased molybdenum content, the amount of fine M2C carbides was greatly increased, while that of coarse M3C carbides was decreased, thereby leading to the improvement of tensile properties and impact toughness. Their simulated HAZs also had sufficient impact toughness after postweld heat treatment (PWHT). These findings suggested that the low-alloy steels with high strength and toughness could be processed by decreasing carbon and manganese contents and by increasing molybdenum content.

  13. Mapping Phase Transformations in the Heat-Affected-Zone of Carbon Manganese Steel Welds using Spatially Resolved X-Ray Diffraction

    SciTech Connect

    Elmer, J W; Wong, J; Ressler, T; Palmer, T A

    2001-12-04

    Spatially Resolved X-Ray Diffraction (SRXRD) was used to investigate phase transformations that occur in the heat affected zone (HAZ) of gas tungsten arc (GTA) welds in AISI 1005 carbon-manganese steel. In situ SRXRD experiments performed at the Stanford Synchrotron Radiation Laboratory (SSRL) probed the phases present in the HAZ during welding, and these real-time observations of the HAZ phases were used to construct a map of the phase transformations occurring in the HAZ. This map identified 5 principal phase regions between the liquid weld pool and the unaffected base metal for the carbon-manganese steel studied in this investigation. Regions of annealing, recrystallization, partial transformation and complete transformation to {alpha}-Fe, {gamma}-Fe, and {delta}-Fe phases were identified using SRXRD, and the experimental results were combined with a heat flow model of the weld to investigate transformation kinetics under both positive and negative temperature gradients in the HAZ. From the resulting phase transformation map, the kinetics of phase transformations that occur under the highly non-isothermal heating and cooling cycles produced during welding of steels can now be better understood and modeled.

  14. Mapping Phase Transformations in the Heat-Affected-Zone of Carbon Manganese Steel Welds using Spatially Resolved X-Ray Diffraction

    SciTech Connect

    Elmer, J W; Wong, J; Ressler, T; Palmer, T A

    2002-02-12

    Spatially Resolved X-Ray Diffraction (SRXRD) was used to investigate phase transformations that occur in the heat affected zone (HAZ) of gas tungsten arc (GTA) welds in AISI 1005 carbon-manganese steel. In situ SRXRD experiments performed at the Stanford Synchrotron Radiation Laboratory (SSRL) probed the phases present in the HAZ during welding, and these real-time observations of the HAZ phases were used to construct a map of the phase transformations occurring in the HAZ. This map identified 5 principal phase regions between the liquid weld pool and the unaffected base metal. Regions of annealing, recrystallization, partial transformation and complete transformation to {alpha}-Fe, {gamma}-Fe, and {delta}-Fe phases were identified using SRXRD, and the experimental results were combined with a heat flow model of the weld and thermodynamic calculations to compare these results with the important phase transformation isotherms. From the resulting phase transformation map, the kinetics of phase transformations that occur under the highly non-isothermal heating and cooling cycles produced during welding of steels can be better understood and modeled.

  15. Estimation of the most influential factors on the laser cutting process heat affected zone (HAZ) by adaptive neuro-fuzzy technique

    NASA Astrophysics Data System (ADS)

    Petković, Dalibor; Nikolić, Vlastimir; Milovančević, Miloš; Lazov, Lyubomir

    2016-07-01

    Heat affected zone (HAZ) of the laser cutting process may be developed on the basis on combination of different factors. In this investigation was analyzed the HAZ forecasting based on the different laser cutting parameters. The main aim in this article was to analyze the influence of three inputs on the HAZ of the laser cutting process. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data in order to select the most influential factors for HAZ forecasting. Three inputs are considered: laser power, cutting speed and gas pressure. According the results the cutting speed has the highest influence on the HAZ forecasting (RMSE: 0.0553). Gas pressure has the smallest influence on the HAZ forecasting (RMSE: 0.0801). The results can be used in order to simplify HAZ prediction and analyzing.

  16. Prediction and characterization of heat-affected zone formation due to neighboring nickel-aluminum multilayer foil reaction

    SciTech Connect

    Adams, David P.; Hirschfeld, Deidre A.; Hooper, Ryan J.; Manuel, Michelle V.

    2015-09-01

    Reactive multilayer foils have the potential to be used as local high intensity heat sources for a variety of applications. Much of the past research effort concerning these materials have focused on understanding the structure-property relationships of the foils that govern the energy released during a reaction. To enhance the ability of researchers to more rapidly develop technologies based on reactive multilayer foils, a deeper and more predictive understanding of the relationship between the heat released from the foil and microstructural evolution in the neighboring materials is needed. This work describes the development of a numerical model for the purpose of evaluating new foil-substrate combinations for screening and optimization. The model is experimentally validated using a commercially available Ni-Al multilayer foils and different alloys.

  17. Zone heating for fluidized bed silane pyrolysis

    NASA Technical Reports Server (NTRS)

    Iya, Sridhar K. (Inventor)

    1987-01-01

    An improved heated fluidized bed reactor and method for the production of high purity polycrystalline silicon by silane pyrolysis wherein silicon seed particles are heated in an upper heating zone of the reactor and admixed with particles in a lower reaction zone, in which zone a silane-containing gas stream, having passed through a lower cooled gas distribution zone not conducive to silane pyrolysis, contacts the heated seed particles whereon the silane is heterogeneously reduced to silicon.

  18. Microstructures and Mechanical Properties of Weld Metal and Heat-Affected Zone of Electron Beam-Welded Joints of HG785D Steel

    NASA Astrophysics Data System (ADS)

    Zhang, Qiang; Han, Jianmin; Tan, Caiwang; Yang, Zhiyong; Wang, Junqiang

    2016-12-01

    Vacuum electron beam welding (EBW) process was employed to butt weld 10-mm-thick HG785D high-strength steels. The penetration into the steel was adjusted by beam current. Microstructures at weld metal and heat-affected zone (HAZ) regions were comparatively observed. Mechanical properties of the EBWed joints including Vickers hardness, tensile and Charpy impact tests were evaluated. The results indicated that microstructures at the weld metal consisted of coarse lath martensite and a small amount of acicular martensite, while that in the HAZ was tempered sorbite and martensite. The grain size in the weld metal was found to be larger than that in the HAZ, and its proportion in weld metal was higher. The hardness in the weld metal was higher than the HAZ and base metal. The tensile strength and impact toughness in the HAZ was higher than that in the weld metal. All the behaviors were related to microstructure evolution caused by higher cooling rates and state of base metal. The fracture surfaces of tensile and impact tests on the optimized joint were characterized by uniform and ductile dimples. The results differed significantly from that obtained using arc welding process.

  19. Laser cutting of graphite anodes for automotive lithium-ion secondary batteries: investigations in the edge geometry and heat-affected zone

    NASA Astrophysics Data System (ADS)

    Schmieder, Benjamin

    2012-03-01

    To serve the high need of lithium-ion secondary batteries of the automobile industry in the next ten years it is necessary to establish highly reliable, fast and non abrasive machining processes. In previous works [1] it was shown that high cutting speeds with several meters per second are achievable. For this, mainly high power single mode fibre lasers with up to several kilo watts were used. Since lithium-ion batteries are very fragile electro chemical systems, the cutting speed is not the only thing important. To guarantee a high cycling stability and a long calendrical life time the edge quality and the heat affected zone (HAZ) are equally important. Therefore, this paper tries to establish an analytical model for the geometry of the cutting edge based on the ablation thresholds of the different materials. It also deals with the composition of the HAZ in dependence of the pulse length, generated by laser remote cutting with pulsed fibre laser. The characterisation of the HAZ was done by optical microscopy, SEM, EDX and Raman microscopy.

  20. The Stress-Relief Cracking Susceptibility of a New Ferritic Steel - Part I: Single-Pass Heat-Affected Zone Simulations

    SciTech Connect

    NAWROCKI,J.G.; DUPONT,J.N.; ROBINO,CHARLES V.; MARDER,A.R.

    1999-12-15

    The stress-relief cracking susceptibility of single-pass welds in a new ferritic steel, HCM2S, has been evaluated and compared to 2.25Cr-1Mo steel using Gleeble techniques. Simulated coarse-grained heat-affected zones (CGHAZ) were produced under a range of energy inputs and tested at various post-weld heat treatment (PWHT) temperatures. Both alloys were tested at a stress of 325 MPa. The 2.25 Cr-1Mo steel was also tested at 270 MPa to normalize for the difference in yield strength between the two materials. Light optical and scanning electron microscopy were used to characterize the CGHAZ microstructure. The ''as-welded'' CGHAZ of each alloy consisted of lath martensite or bainite and had approximately equal prior austenite grain sizes. The as-welded hardness of the 2.25Cr-1Mo steel CGHAZ was significantly higher than that of the HCM2S alloy. Over the range studied energy input had no effect on the as-welded microstructure or hardness of either alloy. The energy input also had no effect on the stress-relief cracking susceptibility of either material. Both alloys failed intergranularly along prior austenite grain boundaries under all test conditions. The 2.25Cr-1Mo steel samples experienced significant macroductility and some microductility when tested at 325 MPa. The ductility decreased significantly when tested at 270 MPa but was still higher that than of HCM2S at each test condition. The time to failure decreased with increasing PWHT Temperature for each material. There was no significant difference in the times to failure between the two materials. Varying energy input and stress had no effect on the time-to failure. The ductility, as measured by reduction in are% increased with increasing PWHT temperature for 2.25 Cr-1Mo steel tested at both stresses. However, PWHT temperature had no effect on the ductility of HCM2S. The hardness of the CGHAZ for 2.25Cr-1Mo steel decreased significantly after PWHT, but remained constant for HCM2S. The differences in stress

  1. Radiant zone heated particulate filter

    DOEpatents

    Gonze, Eugene V [Pinckney, MI

    2011-12-27

    A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

  2. Microstructural Evolution and Mechanical Properties of Simulated Heat-Affected Zones in Cast Precipitation-Hardened Stainless Steels 17-4 and 13-8+Mo

    NASA Astrophysics Data System (ADS)

    Hamlin, Robert J.; DuPont, John N.

    2017-01-01

    Cast precipitation-hardened (PH) stainless steels 17-4 and 13-8+Mo are used in applications that require a combination of high strength and moderate corrosion resistance. Many such applications require fabrication and/or casting repair by fusion welding. The purpose of this work is to develop an understanding of microstructural evolution and resultant mechanical properties of these materials when subjected to weld thermal cycles. Samples of each material were subjected to heat-affected zone (HAZ) thermal cycles in the solution-treated and aged condition (S-A-W condition) and solution-treated condition with a postweld thermal cycle age (S-W-A condition). Dilatometry was used to establish the onset of various phase transformation temperatures. Light optical microscopy (LOM), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS) were used to characterize the microstructures, and comparisons were made to gas metal arc welds that were heat treated in the same conditions. Tensile testing was also performed. MatCalc thermodynamic and kinetic modeling software was used to predict the evolution of copper (Cu)-rich body center cubic precipitates in 17-4 and β-NiAl precipitates in 13-8+Mo. The yield strength was lower in the simulated HAZ samples of both materials prepared in the S-A-W condition when compared to their respective base metals. Samples prepared in the S-W-A condition had higher and more uniform yield strengths for both materials. Significant changes were observed in the matrix microstructure of various HAZ regions depending on the peak temperature, and these microstructural changes were interpreted with the aid of dilatometry results, LOM, SEM, and EDS. Despite these significant changes to the matrix microstructure, the changes in mechanical properties appear to be governed primarily by the precipitation behavior. The decrease in strength in the HAZ samples prepared in the S-A-W condition was attributed to the dissolution of precipitates

  3. Zone heated diesel particulate filter electrical connection

    DOEpatents

    Gonze, Eugene V.; Paratore, Jr., Michael J.

    2010-03-30

    An electrical connection system for a particulate filter is provided. The system includes: a particulate filter (PF) disposed within an outer shell wherein the PF is segmented into a plurality of heating zones; an outer mat disposed between the particulate filter and the outer shell; an electrical connector coupled to the outer shell of the PF; and a plurality of printed circuit connections that extend along the outer surface of the PF from the electrical connector to the plurality of heating zones.

  4. Tempering-Induced Microstructural Changes in the Weld Heat-Affected Zone of 9 to 12 Pct Cr Steels and Their Influence on Sliding Wear

    NASA Astrophysics Data System (ADS)

    Velkavrh, Igor; Kafexhiu, Fevzi; Klien, Stefan; Diem, Alexander; Podgornik, Bojan

    2017-01-01

    Increasing amount of tribological applications is working under alternating high/low temperature conditions where the material is subjected to temperature fatigue mechanisms such as creep, softening due to annealing, and at the same time must withstand mechanical wear due to sliding contact with pairing bodies. Steam turbine valves, gate valves, valve heads, stems, seats and bushings, and contacting surfaces of the carrier elements are some examples of such applications. The purpose of the present study is to evaluate the potential of X20 and P91 steels as materials for applications operating under combined effect of mechanical wear and alternating high/low temperature conditions. It was focused on how the microstructural changes occurring in the weld zone affect the wear properties of the selected materials. Generally, with longer tempering time and higher tempering temperature, the number of carbide precipitates decreased, while their relative spacing increased. Before tempering, the morphology of the steel matrix (grain size, microstructure homogeneity) governed the wear resistance of both steels, while after tempering wear response was determined by the combination of the number and the size of carbide particles. After tempering, in X20 steel larger number of stable M23C6 carbides was observed as compared with P91 steel, resulting in lower wear rates. It was observed that for both steels, a similar combination of number density and size distribution of carbide particles provided the highest wear resistance.

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

    NASA Astrophysics Data System (ADS)

    Shen, Xiangjin; Liu, Binhui

    2016-09-01

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

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

    PubMed Central

    Shen, Xiangjin; Liu, Binhui

    2016-01-01

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

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

    PubMed

    Shen, Xiangjin; Liu, Binhui

    2016-09-21

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

  8. FED. Zoning for TRUMP Heat Transfer Code

    SciTech Connect

    Elrod, D.

    1987-10-23

    FED reduces the effort required to obtain the necessary geometric input for problems which are to be solved using the heat-transfer code, TRUMP. TRUMP calculates transient and steady-state temperature distributions in multidimensional systems. FED can properly zone any body of revolution in one, two, or three dimensions.

  9. Effects of alloying elements on fracture toughness in the transition temperature region of base metals and simulated heat-affected zones of Mn-Mo-Ni low-alloy steels

    NASA Astrophysics Data System (ADS)

    Kim, Sangho; Im, Young-Roc; Lee, Sunghak; Lee, Hu-Chul; Kim, Sung-Joon; Hong, Jun Hwa

    2004-07-01

    This study is concerned with the effects of alloying elements on fracture toughness in the transition temperature region of base metals and heat-affected zones (HAZs) of Mn-Mo-Ni low-alloy steels. Three kinds of steels whose compositions were varied from the composition specification of SA 508 steel (grade 3) were fabricated by vacuum-induction melting and heat treatment, and their fracture toughness was examined using an ASTM E1921 standard test method. In the steels that have decreased C and increased Mo and Ni content, the number of fine M2C carbides was greatly increased and the number of coarse M3C carbides was decreased, thereby leading to the simultaneous improvement of tensile properties and fracture toughness. Brittle martensite-austenite (M-A) constituents were also formed in these steels during cooling, but did not deteriorate fracture toughness because they were decomposed to ferrite and fine carbides after tempering. Their simulated HAZs also had sufficient impact toughness after postweld heat treatment. These findings indicated that the reduction in C content to inhibit the formation of coarse cementite and to improve toughness and the increase in Mo and Ni to prevent the reduction in hardenability and to precipitate fine M2C carbides were useful ways to improve simultaneously the tensile and fracture properties of the HAZs as well as the base metals.

  10. Effects of growth parameters on silicon molten zone formed by infrared convergent-heating floating zone method

    NASA Astrophysics Data System (ADS)

    Hossain, Md. Mukter; Watauchi, Satoshi; Nagao, Masanori; Tanaka, Isao

    2017-02-01

    The effects of rotation rate, filament size, mirror shape, and crystal diameter on the shape of the silicon molten zones prepared using the infrared convergent-heating floating zone method were examined. The crystal rotation rate did not significantly affect the shape of the feed-melt or crystal-melt interfaces, gap between the crystal and feed, zone length, or lamp power required to form the molten zone. More efficient heating was achieved using lamps with smaller filaments and ellipsoidal mirrors with higher eccentricity. The convexity of both the feed and the crystal sides of the molten zone decreased with increasing crystal diameter. However, the required lamp power, gap, and zone length increased with increasing crystal diameter. The stability of the molten zone seemed to reduce with increasing crystal diameter. The minimum melt width divided by the crystal diameter was found to be a good parameter to describe the stability of the molten zone.

  11. Role of microstructural degradation in the heat affected zone of 2.25Cr-1Mo steel weldments on subscale features during steam oxidation and their role in weld failures

    SciTech Connect

    Raman, R.K.S.

    1998-02-01

    Microstructural degradations in the base metal adjacent to the weld pool, i.e., the heat-affected zone (HAZ), caused during welding of 2.25Cr-1Mo steel, were characterized by electron and optical microscopy of different regions of the weldments. In order to study the influence of the microstructural degradations on scaling kinetics in steam and the resulting subscale features, samples of the base metal, the HAZ, and weld metal specimens were extracted from the weldment and oxidized in an environment of 35 pct steam + nitrogen at 873 K for 10 hours. Oxide scales formed in the three regions and the underlying subscales were characterized using scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Influence of the free chromium content in the three weldment regions on protective scale formation and on the subscale features has been investigated. As the principal achievement, this study has clearly shown the occurrence of oxidation-induced void formation in the subscale zone and grain boundary cavitation in the neighboring area during steam oxidation of the HAZ. This article also discusses the possible role of oxidation-induced void formation and grain boundary cavitation in the inferior service life of welds in 2.25Cr-1Mo steel components.

  12. Direct Observations of the (Alpha to Gamma) Transformation at Different Input Powers in the Heat Affected Zone of 1045 C-Mn Steel Arc Welds Observed by Spatially Resolved X-Ray Diffraction

    SciTech Connect

    Palmer, T A; Elmer, J W

    2005-03-16

    Spatially Resolved X-Ray Diffraction (SRXRD) experiments have been performed during Gas Tungsten Arc (GTA) welding of AISI 1045 C-Mn steel at input powers ranging from 1000 W to 3750 W. In situ diffraction patterns taken at discreet locations across the width of the heat affected zone (HAZ) near the peak of the heating cycle in each weld show regions containing austenite ({gamma}), ferrite and austenite ({alpha}+{gamma}), and ferrite ({alpha}). Changes in input power have a demonstrated effect on the resulting sizes of these regions. The largest effect is on the {gamma} phase region, which nearly triples in width with increasing input power, while the width of the surrounding two phase {alpha}+{gamma} region remains relatively constant. An analysis of the diffraction patterns obtained across this range of locations allows the formation of austenite from the base metal microstructure to be monitored. After the completion of the {alpha} {yields} {gamma} transformation, a splitting of the austenite peaks is observed at temperatures between approximately 860 C and 1290 C. This splitting in the austenite peaks results from the dissolution of cementite laths originally present in the base metal pearlite, which remain after the completion of the {alpha} {yields} {gamma} transformation, and represents the formation of a second more highly alloyed austenite constituent. With increasing temperatures, carbon, originally present in the cementite laths, diffuses from the second newly formed austenite constituent to the original austenite constituent. Eventually, a homogeneous austenitic microstructure is produced at temperatures of approximately 1300 C and above, depending on the weld input power.

  13. Nonuniform distribution of carbonitride particles and its effect on prior austenite grain size in the simulated coarse-grained heat-affected zone of thermomechanical control-processed steels

    NASA Astrophysics Data System (ADS)

    Tian, D. W.; Karjalainen, L. P.; Qian, Bainian; Chen, Xiaofeng

    1996-12-01

    The spatial distribution of carbonitride particles in the simulated coarse-grained heat-affected zone (HAZ) of Nb-Ti microalloyed thermomechanical control-processed (TMCP) steels was investigated using a scanning transmission electron microscope (STEM). It was found that the particles in quenched coarse-grained HAZ were frequently distributed in a nonuniform way, forming clusters and arrays of particles. This nonhomogeneity is defined by the grouping tendency of particles and described by the closeness of the average number density (the mean particle number per unit area) to the average local number density (the mean particle number per unit area, excluding the examined areas without particles). A high concentration of Nb (0.04 mass pct in this article) promoted the formation of carbonitride particle arrays and clusters because of its high segregation tendency at grain and subgrain boundaries during the cooling of a slab. Some of these particles remain undissolved at the peak temperature of a welding thermocycle and may result in sympathetic nucleation of new particles on them. The effectiveness of the particle groups to restrict grain growth is discussed.

  14. Overlap zoned electrically heated particulate filter

    DOEpatents

    Gonze, Eugene V [Pinckney, MI; Chapman, Mark R [Brighton, MI

    2011-07-19

    A system includes a particulate matter (PM) filter that includes an upstream end for receiving exhaust gas and a downstream end. A zoned heater is arranged spaced from the upstream end and comprises N zones, where N is an integer greater than one, wherein each of the N zones comprises M sub-zones, where M is an integer greater than or equal to one, and wherein the N zones and the M sub-zones are arranged in P layers, where P is an integer greater than one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates non-selected ones of the N zones.

  15. Europa, tidally heated oceans, and habitable zones around giant planets

    NASA Technical Reports Server (NTRS)

    Reynolds, Ray T.; Mckay, Christopher P.; Kasting, James F.

    1987-01-01

    Tidal dissipation in the satellites of a giant planet may provide sufficient heating to maintain an environment favorable to life on the satellite surface or just below a thin ice layer. Europa could have a liquid ocean which may occasionally receive sunlight through cracks in the overlying ice shell. In such a case, sufficient solar energy could reach liquid water that organisms similar to those found under Antarctic ice could grow. In other solar systems, larger satellites with more significant heat flow could represent environments that are stable over an order of eons and in which life could perhaps evolve. A zone around a giant planet is defined in which such satellites could exist as a tidally-heated habitable zone. This zone can be compared to the habitable zone which results from heating due to the radiation of a central star. In this solar system, this radiatively-heated habitable zone contains the earth.

  16. Varying heating in dawsonite zones in hydrocarbon containing formations

    DOEpatents

    Vinegar, Harold J.; Xie, Xueying; Miller, David Scott

    2009-07-07

    A method for treating an oil shale formation comprising dawsonite includes assessing a dawsonite composition of one or more zones in the formation. Heat from one or more heaters is provided to the formation such that different amounts of heat are provided to zones with different dawsonite compositions. The provided heat is allowed to transfer from the heaters to the formation. Fluids are produced from the formation.

  17. Relationship between crystallographic structure of the Ti{sub 2}O{sub 3}/MnS complex inclusion and microstructure in the heat-affected zone (HAZ) in steel processed by oxide metallurgy route and impact toughness

    SciTech Connect

    Xiong, Zhihui; Liu, Shilong; Wang, Xuemin; Shang, Chengjia; Misra, R.D.K.

    2015-08-15

    A new method based on electron back scattered diffraction (EBSD) is proposed to determine the structure of titanium oxide/MnS complex inclusion which induced the formation of intragranular acicular ferrite (IAF) in heat-affected zone (HAZ) in steel processed by oxide metallurgy route. It was found that the complex inclusion was Ti{sub 2}O{sub 3}/MnS, the orientation relationship between Ti{sub 2}O{sub 3} and MnS was also examined, and the crystallographic orientation relationship among IAF, Ti{sub 2}O{sub 3}/MnS complex inclusion, austenite, bainite formed at lower temperature is researched systematically. It was observed that MnS precipitated on Ti{sub 2}O{sub 3} at specific habit plane and direction and MnS had a specific orientation relationship ((0001) Ti{sub 2}O{sub 3}//(111) MnS), <10–10> Ti{sub 2}O{sub 3}//<110> MnS) with respect to Ti{sub 2}O{sub 3}. Intragranular acicular ferrite (IAF) nucleated on MnS part of the Ti{sub 2}O{sub 3}/MnS complex inclusion had no specific orientation relationship with MnS. IAF and the surrounding bainite had different Bain groups, so that there was an increase in high angle boundaries, which was beneficial for the toughness of HAZ. - Highlights: • The inclusion of TiO{sub x}/MnS that induced IAF formation is identified to be Ti{sub 2}O{sub 3}/MnS. • The inclusion is identified based on electron back scattered diffraction (EBSD). • MnS and Ti{sub 2}O{sub 3} had specific orientation relationship of Ti{sub 2}O{sub 3}/MnS complex inclusion. • The IAFs formed on the same inclusion tend to be in one Bain group. • IAF and the surrounding bainite tend to be in different Bain groups.

  18. Heat transport dynamics at a sandy intertidal zone

    NASA Astrophysics Data System (ADS)

    Befus, Kevin M.; Cardenas, M. Bayani; Erler, Dirk V.; Santos, Isaac R.; Eyre, Bradley D.

    2013-06-01

    Intertidal zones are spatially complex and temporally dynamic environments. Coastal groundwater discharge, including submarine groundwater discharge, may provide stabilizing conditions for intertidal zone permeable sediments. In this study, we integrated detailed time series temperature observations, porewater pressure measurements, and two-dimensional electrical resistivity tomography profiles to understand the coupled hydraulic-thermal regime of a tropical sandy intertidal zone in a fringing coral reef lagoon (Rarotonga, Cook Islands). We found three heating patterns across the 15 m study transect over tidal and diel periods: (1) a highly variable thermal regime dominated by swash infiltration and changes in saturation state in the upper foreshore with net heat import into the sediment, (2) a groundwater-supported underground stable, cool region just seaward of the intertidal slope break also importing heat into the subsurface, and (3) a zone of seawater recirculation that sustained consistently warm subsurface temperatures that exported heat across the sediment-water interface. Simple calculations suggested thermal conduction as the main heat transport mechanism for the shallow intertidal sediment, but deeper and/or multidimensional groundwater flow was required to explain temperature patterns beyond 20 cm depth. Temperature differences between the distinct hydrodynamic zones of the foreshore site resulted in significant thermal gradients that persisted beyond tidal and diel periods. The thermal buffering of intertidal zones by coastal groundwater systems, both at surface seeps and in the shallow subsurface, can be responsible for thermal refugia for some coastal organisms and hotspots for biogeochemical reactions.

  19. Numerical simulations of inductive-heated float-zone growth

    NASA Technical Reports Server (NTRS)

    Chan, Y. T.; Choi, S. K.

    1992-01-01

    The present work provides an improved fluid flow and heat-transfer modeling of float-zone growth by introducing a RF heating model so that an ad hoc heating temperature profile is not necessary. Numerical simulations were carried out to study the high-temperature float-zone growth of titanium carbide single crystal. The numerical results showed that the thermocapillary convection occurring inside the molten zone tends to increase the convexity of the melt-crystal interface and decrease the maximum temperature of the molten zone, while the natural convection tends to reduce the stability of the molten zone by increasing its height. It was found that the increase of induced heating due to the increase of applied RF voltage is reduced by the decrease of zone diameter. Surface tension plays an important role in controlling the amount of induced heating. Finally, a comparison of the computed shape of the free surface with a digital image obtained during a growth run showed adequate agreement.

  20. Europa, tidally heated oceans, and habitable zones around giant planets.

    PubMed

    Reynolds, R T; McKay, C P; Kasting, J F

    1987-01-01

    Tidal dissipation in the satellites of a giant planet may provide sufficient heating to maintain an environment favorable to life on the satellite surface or just below a thin ice layer. In our own solar system, Europa, one of the Galilean satellites of Jupiter, could have a liquid ocean which may occasionally receive sunlight through cracks in the overlying ice shell. In such case, sufficient solar energy could reach liquid water that organisms similar to those found under Antarctic ice could grow. In other solar systems, larger satellites with more significant heat flow could represent environments that are stable over an order of Aeons and in which life could perhaps evolve. We define a zone around a giant planet in which such satellites could exist as a tidally-heated habitable zone. This zone can be compared to the habitable zone which results from heating due to the radiation of a central star. In our solar system, this radiatively-heated habitable zone contains the Earth.

  1. Can fault slip affect vitrinite reflectance without heat?

    NASA Astrophysics Data System (ADS)

    Fulton, P. M.; Kitamura, M.; Mukoyoshi, H.; Hirose, T.

    2012-12-01

    increased displacement. However, this very small increase is within the standard deviation amongst measurements and is not likely significant. In addition, the spatial distribution of Rmax, Rmin, and anisotropy values all appear randomly distributed within the thin sections and do not appear concentrated in zones of strain localization. Our results suggest that, at least for clay dominated gouge zones, there is essentially no non-thermal effect on vitrinite reflectance under a reasonable range of slip rates and displacements typical of earthquakes and for conditions likely applicable for the shallow toe of subduction zones where IODP fault zone cores have recently been obtained (e.g., Nankai and Japan Trench). Observations of increases in R in such locations would thus likely reflect the effects of frictional heating, although how the mechanical effects of shearing combined with fast heating may affect the kinetics requires further evaluation in order to accurately assess peak temperature values.

  2. Shear heating in continental strike-slip shear zones:model and field examples

    NASA Astrophysics Data System (ADS)

    Leloup, Philippe Hervé; Ricard, Yannick; Battaglia, Jean; Lacassin, Robin

    1999-01-01

    A two-layer (crust and upper mantle), finite difference steady-state thermomechanical model of a long-lived (several million years) lithospheric strike-slip fault is presented, and its predictions compared with field observations from various major fault zones. In order to estimate the maximum amount of shear heating, all mechanical energy is assumed to be dissipated in heat, in ductile as well as in brittle layers. Deformation follows a friction law in the brittle layer(s), and a power-flow law in the ductile one(s). Variations of several independent parameters and their influence on the thermo-mechanical state of the fault zone and on shear heating are systematically explored. Shear heating is found to be more important in fault zones affecting an initially cold lithosphere, and increases with slip rate, friction coefficient and stiffness of materials. In extreme cases (slip rate of 10 cm yr^-1, stiff lithosphere), shear heating could lead to temperature increases close to 590 degC at the Moho, and 475 degC at 20 km depth. For more common cases, shear heating leads to smaller temperature increases, but can still explain high-grade metamorphic conditions encountered in strike-slip shear zones. However, modelled temperature conditions often fall short of those observed. This could be due to heat transport by mechanisms more efficient than conduction. Common syntectonic emplacement of granitic melts in ductile strike-slip shear zones can be explained by lower crust partial melting induced by shear heating in the upper mantle. Besides slip rate, the possibility of such melting depends mostly on the upper mantle rheology and on the fertility of the lower crust: for hard upper mantle and highly fertile lower crust, partial melting could occur at rates of 1 cm yr^-1, while in most cases it would result from the breakdown of micas for slip rates over 3 cm yr^-1. As a result of shear heating, partial melting of the upper mantle could occur in the presence of small amounts

  3. Heat flow and energetics of the San Andreas fault zone.

    USGS Publications Warehouse

    Lachenbruch, A.H.; Sass, J.H.

    1980-01-01

    Approximately 100 heat flow measurements in the San Andreas fault zone indicate 1) there is no evidence for local frictional heating of the main fault trace at any latitude over a 1000-km length from Cape Mendocino to San Bernardino, 2) average heat flow is high (ca.2 HFU, ca.80 mW m-2) throughout the 550-km segment of the Coast Ranges that encloses the San Andreas fault zone in central California; this broad anomaly falls off rapidly toward the Great Valley to the east, and over a 200-km distance toward the Mendocino Triple Junction to the northwest. As others have pointed out, a local conductive heat flow anomaly would be detectable unless the frictional resistance allocated to heat production on the main trace were less than 100 bars. Frictional work allocated to surface energy of new fractures is probably unimportant, and hydrologic convection is not likely to invalidate the conduction assumption, since the heat discharge by thermal springs near the fault is negligible. -Authors

  4. Root-Zone Glyphosate Exposure Adversely Affects Two Ditch Species

    PubMed Central

    Saunders, Lyndsay E.; Koontz, Melissa B.; Pezeshki, Reza

    2013-01-01

    Glyphosate, one of the most applied herbicides globally, has been extensively studied for its effects on non-target organisms. In the field, following precipitation, glyphosate runs off into agricultural ditches where it infiltrates into the soil and thus may encounter the roots of vegetation. These edge-of-field ditches share many characteristics with wetlands, including the ability to reduce loads of anthropogenic chemicals through uptake, transformation, and retention. Different species within the ditches may have a differential sensitivity to exposure of the root zone to glyphosate, contributing to patterns of abundance of ruderal species. The present laboratory experiment investigated whether two species commonly found in agricultural ditches in southcentral United States were affected by root zone glyphosate in a dose-dependent manner, with the objective of identifying a sublethal concentration threshold. The root zone of individuals of Polygonum hydropiperoides and Panicum hemitomon were exposed to four concentrations of glyphosate. Leaf chlorophyll content was measured, and the ratio of aboveground biomass to belowground biomass and survival were quantified. The findings from this study showed that root zone glyphosate exposure negatively affected both species including dose-dependent reductions in chlorophyll content. P. hydropiperdoides showed the greatest negative response, with decreased belowground biomass allocation and total mortality at the highest concentrations tested. PMID:24833234

  5. 49 CFR 222.42 - How does this rule affect Intermediate Quiet Zones and Intermediate Partial Quiet Zones?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... and Intermediate Partial Quiet Zones? 222.42 Section 222.42 Transportation Other Regulations Relating... Horns at Groups of Crossings-Quiet Zones § 222.42 How does this rule affect Intermediate Quiet Zones and..., if the public authority provides Notice of Quiet Zone Continuation, in accordance with § 222.43...

  6. Heat flow and energetics of the San Andreas Fault Zone

    NASA Astrophysics Data System (ADS)

    Lachenbruch, Arthur H.; Sass, J. H.

    1980-11-01

    Approximately 100 heat flow measurements in the San Andreas fault zone indicate (1) there is no evidence for local factional heating of the main fault trace at any latitude over a 1000-km length from Cape Mendocino to San Bernardino, (2) average heat flow is high (˜2 HFU, ˜80 mW m-2) throughout the 550-km segment of the Coast Ranges that encloses the San Andreas fault zone in central California; this broad anomaly falls off rapidly toward the Great Valley to the east, and over a 200-km distance toward the Mendocino Triple Junction to the northwest. As others have pointed out, a local conductive heat flow anomaly would be detectable unless the frictional resistance allocated to heat production on the main trace were ≲100 bars. Frictional work allocated to surface energy of new fractures is probably unimportant, and hydrologic convection is not likely to invalidate the conduction assumption, since the heat discharge by thermal springs near the fault is negligible. Explanations for the low dynamic friction fall into two intergradational classes: those in which the fault is weak all of the time and those in which it is weak only during earthquakes (possibly just large ones). The first class includes faults containing anomalously weak gouge materials and faults containing materials with normal frictional properties under near-lithostatic steady state fluid pressures. In the second class, weakening is caused by the event (for example, a thermally induced increase in fluid pressure, dehydration of clay minerals, or acoustic fluidization). In this class, unlike the first, the average strength and ambient tectonic shear stress may be large, ˜1 kbar, but the stress allocated to elastic radiation (the apparent stress) must be of similar magnitude, an apparent contradiction with seismic estimates. Unless seismic radiation is underestimated for large earthquakes, it is difficult to justify average tectonic stresses on the main trace of the San Andreas fault in excess of

  7. Finite element analysis of heat transport in a hydrothermal zone

    SciTech Connect

    Bixler, N.E.; Carrigan, C.R.

    1987-01-01

    Two-phase heat transport in the vicinity of a heated, subsurface zone is important for evaluation of nuclear waste repository design and estimation of geothermal energy recovery, as well as prediction of magma solidification rates. Finite element analyses of steady, two-phase, heat and mass transport have been performed to determine the relative importance of conduction and convection in a permeable medium adjacent to a hot, impermeable, vertical surface. The model includes the effects of liquid flow due to capillarity and buoyancy and vapor flow due to pressure gradients. Change of phase, with its associated latent heat effects, is also modeled. The mechanism of capillarity allows for the presence of two-phase zones, where both liquid and vapor can coexist, which has not been considered in previous investigations. The numerical method employs the standard Galerkin/finite element method, using eight-node, subparametric or isoparametric quadrilateral elements. In order to handle the extreme nonlinearities inherent in two-phase, nonisothermal, porous-flow problems, steady-state results are computed by integrating transients out to a long time (a method that is highly robust).

  8. Heat protection behaviors and positive affect about heat during the 2013 heat wave in the United Kingdom.

    PubMed

    Lefevre, Carmen E; Bruine de Bruin, Wändi; Taylor, Andrea L; Dessai, Suraje; Kovats, Sari; Fischhoff, Baruch

    2015-03-01

    Heat waves pose serious health risks, and are expected to become more frequent, longer lasting, and more intense in the future under a changing climate. Yet, people in the UK seem to feel positive when thinking about hot weather. According to research on the affect heuristic, any positive or negative emotions evoked by potentially risky experiences may be used as cues to inform concerns about risk protection. If so, then their positive feelings toward hot weather might lead UK residents to lower intentions to adopt heat protection behaviors. Here, we examine the relationships between heat protection behaviors during the July 2013 UK heat wave and self-reports of having heard heat protection recommendations, feeling positive affect about heat, seeing heat protection measures as effective, and trusting the organizations making those recommendations. Responses to a national survey revealed that 55.1% of participants had heard heat protection recommendations during the 2013 UK heat wave. Those who reported having heard recommendations also indicated having implemented more heat protection behaviors, perceiving heat protection behaviors as more effective, feeling more positive about heat, and intending to implement more protection behaviors in future hot summers. Mediation analyses suggested that heat protection recommendations may motivate heat protection behaviors by increasing their perceived effectiveness, but undermine their implementation by evoking positive affect about hot weather. We discuss our findings in the context of the affect heuristic and its implications for heat protection communications.

  9. Heliocentric zoning of the asteroid belt by aluminum-26 heating

    NASA Technical Reports Server (NTRS)

    Grimm, R. E.; Mcsween, H. Y., Jr.

    1993-01-01

    Variations in petrology among meteorites attest to a strong heating event early in solar system history, but the heat source has remained unresolved. Aluminum-26 has been considered the most likely high-energy, short-lived radionuclide (half-life 0.72 million years) since the discovery of its decay product - excess Mg-26 - in Allende CAI's. Furthermore, observation of relict Mg-26 in an achondritic clast and in feldspars within ordinary chondrites (3,4) provided strong evidence for live Al-26 in meteorite parent bodies and not just in refractory nebular condensates. The inferred amount of Al-26 is consistent with constraints on the thermal evolution of both ordinary and carbonaceous chondrite parent objects up to a few hundred kilometers in diameter. Meteorites can constrain the early thermal evolution of their parent body locations, provided that a link can be established between asteroid spectrophotometric signature and meteorite class. Asteroid compositions are heliocentrically distributed: objects thought to have experienced high metamorphic or even melting temperatures are located closer to the sun, whereas apparently unaltered or mildly heated asteroids are located farther away. Heliocentric zoning could be the result of Al-26 heating if the initial amount of the radionuclide incorporated into planetesimals was controlled by accretion time, which in turn varies with semimajor axis. Analytic expressions for planetary accretion may be integrated to given the time, tau, required for a planetesimal to grow to a specified radius: tau varies as a(sup n), where n = 1.5 to 3 depending on the assumptions about variations in the surface density of the planetesimal swarm. Numerical simulations of planetesimal accretion at fixed semimajor axis demonstrate that variations in accretion time among small planetesimals can be strongly nonlinear depending on the initial conditions and model assumptions. The general relationship with semimajor axis remains valid because it

  10. High exhaust temperature, zoned, electrically-heated particulate matter filter

    DOEpatents

    Gonze, Eugene V.; Paratore, Jr., Michael J.; Bhatia, Garima

    2015-09-22

    A system includes a particulate matter (PM) filter, an electric heater, and a control circuit. The electric heater includes multiple zones, which each correspond to longitudinal zones along a length of the PM filter. A first zone includes multiple discontinuous sub-zones. The control circuit determines whether regeneration is needed based on an estimated level of loading of the PM filter and an exhaust flow rate. In response to a determination that regeneration is needed, the control circuit: controls an operating parameter of an engine to increase an exhaust temperature to a first temperature during a first period; after the first period, activates the first zone; deactivates the first zone in response to a minimum filter face temperature being reached; subsequent to deactivating the first zone, activates a second zone; and deactivates the second zone in response to the minimum filter face temperature being reached.

  11. SiC growth by Solvent-Laser Heated Floating Zone

    NASA Technical Reports Server (NTRS)

    Woodworth, Andrew A.; Neudeck, Philip G.; Sayir, Ali; Spry, David J.; Trunek, Andrew J.; Powell, J. Anthony

    2011-01-01

    In an effort to grow single crystal SiC fibers for seed crystals the following two growth methods have been coupled in this work: traveling solvent and laser heated floating zone to create the solvent-laser heated floating zone (Solvent-LHFZ) crystal growth method. This paper discusses the results of these initial experiments, which includes: source material, laser heating, and analysis of the first ever Solvent-LHFZ SiC crystals (synchrotron white beam x-ray topography confirmed).

  12. Heat Flow and Fluid Flux in Cascadia's Seismogenic Zone

    NASA Astrophysics Data System (ADS)

    Johnson, H. Paul; Solomon, Evan A.; Harris, Robert N.; Salmi, Marie S.; Berg, Richard D.

    2013-11-01

    The Cascadia Subduction Zone in the northeast Pacific has generated a large number of megathrust earthquakes and poses the greatest recognized seismic hazard to the northwestern United States. To learn more about the risks this subduction zone poses, scientists from Washington and Oregon conducted a research cruise in August aboard the R/V Atlantis to collect data that would estimate the thermal structure of the "fully locked zone" of the Cascadia megathrust fault. This locked zone resists the continuous motion of two tectonic plates as they collide, storing compressional energy that produces large megathrust earthquakes when released by the abrupt failure of the locking process.

  13. Electrically heated particulate filter with zoned exhaust flow control

    SciTech Connect

    Gonze, Eugene V

    2012-06-26

    A system includes a particulate matter (PM) filter that includes X zones. An electrical heater includes Y heater segments that are associated with respective ones of the X zones. The electrical heater is arranged upstream from and proximate with the PM filter. A valve assembly includes Z sections that are associated with respective ones of the X zones. A control module adjusts flow through each of the Z sections during regeneration of the PM filter via control of the valve assembly. X, Y and Z are integers.

  14. Tularosa Basin Play Fairway Analysis: Partial Basin and Range Heat and Zones of Critical Stress Maps

    DOE Data Explorer

    Adam Brandt

    2015-11-15

    Interpolated maps of heat flow, temperature gradient, and quartz geothermometers are included as TIF files. Zones of critical stress map is also included as a TIF file. The zones are given a 5km diameter buffer. The study area is only a part of the Basin and Range, but it does includes the Tularosa Basin.

  15. 49 CFR 222.41 - How does this rule affect Pre-Rule Quiet Zones and Pre-Rule Partial Quiet Zones?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Pre-Rule Partial Quiet Zones? 222.41 Section 222.41 Transportation Other Regulations Relating to... Groups of Crossings-Quiet Zones § 222.41 How does this rule affect Pre-Rule Quiet Zones and Pre-Rule...-Rule Quiet Zone may be established by automatic approval and remain in effect, subject to § 222.51,...

  16. Percolation induced heat transfer in deep unsaturated zones

    USGS Publications Warehouse

    Lu, N.; LeCain, G.D.

    2003-01-01

    Subsurface temperature data from a borehole located in a desert wash were measured and used to delineate the conductive and advective heat transfer regimes, and to estimate the percolation quantity associated with the 1997-1998 El Ni??no precipitation. In an arid environment, conductive heat transfer dominates the variation of shallow subsurface temperature most of the time, except during sporadic precipitation periods. The subsurface time-varying temperature due to conductive heat transfer is highly correlated with the surface atmospheric temperature variation, whereas temperature variation due to advective heat transfer is strongly correlated with precipitation events. The advective heat transfer associated with precipitation and infiltration is the focus of this paper. Disruptions of the subsurface conductive temperature regime, associated with the 1997-1998 El Ni??no precipitation, were detected and used to quantify the percolation quantity. Modeling synthesis using a one-dimensional coupled heat and unsaturated flow model indicated that a percolation per unit area of 0.7 to 1.3 m height of water in two weeks during February 1998 was responsible for the observed temperature deviations down to a depth of 35.2 m. The reported study demonstrated quantitatively, for the first time, that the near surface temperature variation due to advective heat transfer can be significant at a depth greater than 10 m in unsaturated soils and can be used to infer the percolation amount in thick unsaturated soils.

  17. Observations of joule and particle heating in the auroral zone

    NASA Technical Reports Server (NTRS)

    Banks, P. M.

    1977-01-01

    Observational data from the Chatanika, Alaska incoherent scatter radar have been used to deduce atmospheric heating rates associated with particle precipitation and joule dissipation. During periods when Chatanika is in the vicinity of the auroral oval the height-integrated heat input to the lower thermosphere can be as large as 100 ergs per sq cm per sec with joule and particle heating rates of comparable magnitude. Altitude profiles of these heat inputs are also obtained, showing that the energy liberated by joule dissipation tends to peak at a substantially higher altitude (about 130 km) than that due to particles (100-120 km). As a consequence, it follows that joule heating can be expected to provide a rapid means for creating thermospheric disturbances. It is also pointed out that joule and particle heating are permanent features of the auroral oval and polar cap. As such, expansion of the auroral oval leads to an increase in the total global heating and, hence, to the close relationship between magnetic disturbances and thermospheric perturbation.

  18. Heat Transfer at the Reattachment Zone of Separated Laminar Boundary Layers

    NASA Technical Reports Server (NTRS)

    Chung, Paul M.; Viegas, John R.

    1961-01-01

    The flow and heat transfer are analyzed at the reattachment zone of two-dimensional separated laminar boundary layers. The fluid is considered to be flowing normal to the wall at reattachment. An approximate expression is derived for the heat transfer in the reattachment region and a calculated value is compared with an experimental measurement.

  19. Schisandrin A and B affect subventricular zone neurogenesis in mouse.

    PubMed

    Sun, Yi-Xue; Cong, Yan-Long; Liu, Yang; Jin, Bo; Si, Lu; Wang, Ai-Bing; Cai, Huan; Che, Guan-Yu; Tang, Bo; Wang, Chun-Feng; Li, Zi-Yi; Zhang, Xue-Ming

    2014-10-05

    Schisandrin A and B (Sch A and B) are the main effective components extracted from the oriental medicine Schisandra chinensis which is traditionally used to enhance mental and intellectual function. Although their neuroprotective effects have been demonstrated, their influences on neurogenesis are still unknown. In the brain, new neural cells born in the subventricular zone (SVZ) next to the lateral ventricles migrate along the rostral migratory stream (RMS) to the olfactory bulb (OB). To investigate the effects of Sch A and B on neurogenesis in the SVZ-RMS-OB system, Sch A and B were intragastrically administrated at dosages of 1, 10 and 20 mg/kg d respectively. The dose of 10 mg/kg d was selected for further analysis based on the preliminary analysis. In the SVZ, significant increases of phosphohistone H3 positive proliferating cells and the intensity of glial fibrillary acidic protein (GFAP+) cells were noticed in Sch B group. In the RMS, Sch A treatment augmented the intensity of doublecortin positive neuroblasts. In the OB, Sch A decreased tyrosine hydroxylase cells and Calbindin (CalB+) cells, while Sch B increased CalB+ cells and Calretinin (CalR+) cells. These results suggest that Sch B stimulates SVZ proliferation by enhancing GFAP+ cells and improves the survival of OB interneurons, while Sch A promotes neuroblast formation in the RMS but impairs the survival of OB interneurons. The present study provides the first evidence that Sch B exerts neuroprotective functions by enhancing neurogenesis, but Sch A mainly negatively regulates neurogenesis, in the adult SVZ-RMS-OB system.

  20. Periodic Viscous Shear Heating Instability in Fine-Grained Shear Zones: Mechanism for Intermediate Depth Earthquakes

    NASA Astrophysics Data System (ADS)

    Coon, E.; Kelemen, P.; Hirth, G.; Spiegelman, M.

    2005-12-01

    Kelemen and Hirth (Fall 2004 AGU) presented a model for periodic, viscous shear heating instabilities along pre-existing, fine grained shear zones. This provides an attractive alternative to dehydration embrittlement for explaining intermediate-depth earthquakes, especially those in a narrow thermal window within the mantle section of subducting oceanic plates (Hacker et al JGR03). Ductile shear zones with widths of cm to m are common in shallow mantle massifs and peridotite along oceanic fracture zones. Pseudotachylites in a mantle shear zone show that shear heating temperatures exceeded the mantle solidus (Obata & Karato Tectonophys95). Olivine grain growth in shear zones is pinned by closely spaced pyroxenes; thus, once formed, these features do not `heal' on geological time scales in the absence of melt or fluid (Warren & Hirth EPSL05). Grain-size sensitive creep will be localized within these shear zones, in preference to host rocks with olivine grain size from 1 to 10 mm. Inspired by the work of Whitehead & Gans (GJRAS74), we proposed that such pre-existing shear zones might undergo repeated shear heating instabilities. This is not a new concept; what is new is that viscous deformation is limited to a narrow shear zone, because grain boundary sliding, sensitive to both stress and grain size, may accommodate creep even at high stress and high temperature. These new ideas yield a new result: simple models for a periodic shear heating instability. Last year, we presented a 1D numerical model using olivine flow laws, assuming that viscous deformation remains localized in shear zones, surrounded by host rocks undergoing elastic deformation. Stress evolves due to elastic strain and drives viscous deformation in a shear zone of specified width. Shear heating and thermal diffusion control T. A maximum of 1400 C (substantial melting of peridotite ) was imposed. Grain size evolves due to recrystallization and diffusion. For strain rates of E-13 to E-14 per sec and

  1. Modeling ohmic heating in the drying zone of the plasma shaft electric furnace, when recycling the technogenic waste

    NASA Astrophysics Data System (ADS)

    Aliferov, A. I.; Anshakov, A. S.; Sinitsyn, V. A.; Domarov, P. V.; Danilenko, A. A.

    2016-10-01

    Efficient use of ohmic heating in the drying zone of the plasma shaft furnace for gasification of organic and technogenic wastes is studied. It is shown that by using ohmic heating in the drying zone, energy release takes place in the filling along the entire zone.

  2. Zone heated inlet ignited diesel particulate filter regeneration

    DOEpatents

    Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

    2012-06-26

    An exhaust system that processes exhaust generated by an engine is provided. The system includes: a particulate filter (PF) that is disposed downstream of the engine and that filters particulates from the exhaust; and a grid that includes electrically resistive material that is segmented by non-conductive material into a plurality of zones and wherein the grid is applied to an exterior upstream surface of the PF.

  3. Attenuating the surface Urban Heat Island within the Local Thermal Zones through land surface modification.

    PubMed

    Wang, Jiong; Ouyang, Wanlu

    2017-02-01

    Inefficient mitigation of excessive heat is attributed to the discrepancy between the scope of climate research and conventional planning practice. This study approaches this problem at both domains. Generally, the study, on one hand, claims that the climate research of the temperature phenomenon should be at local scale, where implementation of planning and design strategies can be more feasible. On the other hand, the study suggests that the land surface factors should be organized into zones or patches, which conforms to the urban planning and design manner. Thus in each zone, the land surface composition of those excessively hot places can be compared to the zonal standard. The comparison gives guidance to the modification of the land surface factors at the target places. Specifically, this study concerns the Land Surface Temperature (LST) in Wuhan, China. The land surface is classified into Local Thermal Zones (LTZ). The specifications of temperature sensitive land surface factors are relative homogeneous in each zone and so is the variation of the LST. By extending the city scale analysis of Urban Heat Island into local scale, the Local Surface Urban Heat Islands (LSUHIs) are extracted. Those places in each zone that constantly maintain as LSUHI and exceed the homogenous LST variation are considered as target places or hotspots with higher mitigation or adaptation priority. The operation is equivalent to attenuate the abnormal LST variation in each zone. The framework is practical in the form of prioritization and zoning, and mitigation strategies are essentially operated locally.

  4. Natural convection in a vertical rectangular enclosure with localized heating and cooling zones

    NASA Astrophysics Data System (ADS)

    Ishihara, I.; Matsumoto, R.; Senoo, A.

    Experimental and numerical studies of natural convection in a single phase, closed thermosyphon were carried out using a vertical, rectangular enclosure model. Only one vertical plate plays the role of heat transfer surface having 100mm height and 100mm width, and others act as the adiabatic wall made of transparent plexi-glass. The heat transfer surface is separated into three horizontal zones with an equal height; top 1/3 and bottom 1/3 of the surface are cooling and heating zones, respectively and intermediate section is an adiabatic zone. Water is used as the working fluid. Variable parameters are distance D between the heat transfer surface and an adiabatic plate opposite to the heat transfer plate, and temperature difference ΔT between heating and cooling zones. By changing both D and ΔT, three regimes of the natural convection flow; quasi-two-dimensional steady, three-dimensional steady and unsteady flows are observed by means of thermo-sensitive liquid crystal powder and numerically simulated very well by solving a set of governing equations.

  5. Effect of Heat Treatment on Microstructure and Hot Impact Toughness of Various Zones of P91 Welded Pipes

    NASA Astrophysics Data System (ADS)

    Pandey, C.; Mahapatra, M. M.

    2016-06-01

    The new generation super critical thermal power plants are required to operate at enhanced thermal efficiency of over 50% to reduce the fuel consumption and environmental pollution. Creep strength-enhanced ferritic steels, commonly known as Cr-Mo alloys such as P91 (X10CrMoVNb 9-1) are such material of choice for the next generation power plants. The operating requirement of these next generation power plants is that steam temperature of around 650 °C is maintained. For such high-temperature application, creep strength of material is the primary consideration together with adequate weld heat-affected zone (HAZ) toughness. Present work deals with the effect of high service temperature on impact toughness of P91 (X10CrMoVNb 9-1) base material, weld fusion zone, and HAZ. The impact toughness of HAZ for conventional weld groove design and narrow weld groove design has been evaluated experimentally in as-welded and at different post-weld heat treatment conditions. Fractography of the impact toughness specimens of base metal, weld fusion zone, and HAZ was carried out using scanning electron microscope. The effects of heat treatment schemes on the percentage of element present at the fracture surface were also studied.

  6. A New Method to Grow SiC: Solvent-Laser Heated Floating Zone

    NASA Technical Reports Server (NTRS)

    Woodworth, A. A.; Neudeck, Philip G.; Sayir, Ali

    2012-01-01

    The solvent-laser heated floating zone (solvent-LHFZ) growth method is being developed to grow long single crystal SiC fibers. The technique combines the single crystal fiber growth ability of laser heated floating zone with solvent based growth techniques (e.g. traveling solvent method) ability to grow SiC from the liquid phase. Initial investigations reported in this paper show that the solvent-LHFZ method readily grows single crystal SiC (retains polytype and orientation), but has a significant amount of inhomogeneous strain and solvent rich inclusions.

  7. Strain heating in process zones; implications for metamorphism and partial melting in the lithosphere

    NASA Astrophysics Data System (ADS)

    Devès, Maud H.; Tait, Stephen R.; King, Geoffrey C. P.; Grandin, Raphaël

    2014-05-01

    Since the late 1970s, most earth scientists have discounted the plausibility of melting by shear-strain heating because temperature-dependent creep rheology leads to negative feedback and self-regulation. This paper presents a new model of distributed shear-strain heating that can account for the genesis of large volumes of magmas in both the crust and the mantle of the lithosphere. The kinematic (geometry and rates) frustration associated with incompatible fault junctions (e.g. triple-junction) prevents localisation of all strain on the major faults. Instead, deformation distributes off the main faults forming a large process zone that deforms still at high rates under both brittle and ductile conditions. The increased size of the shear-heated region minimises conductive heat loss, compared with that commonly associated with narrow shear zones, thus promoting strong heating and melting under reasonable rheological assumptions. Given the large volume of the heated zone, large volumes of melt can be generated even at small melt fractions.

  8. Shallow thermal structure constrained by seafloor temperature and heat flow estimated from BSRs in the Nankai subduction zone

    NASA Astrophysics Data System (ADS)

    Ohde, A.; Otsuka, H.; Kioka, A.; Ashi, J.

    2015-12-01

    The Nankai Trough is a plate convergent boundary where earthquakes with a magnitude of 8 take place repeatedly. Thermal structure in subduction zones affects pore pressure and diagenesis such as consolidation, dewatering and cementation, and constrains physical properties of a fault-slip plane. In the Nankai subduction zone, existence of methane hydrate is confirmed from acoustic reflectors called the Bottom Simulating Reflectors (BSRs) which parallel the seafloor on seismic reflection images with high-amplitude and reverse-polarity waveforms. As a depth of BSR is theoretically constrained by subseafloor profiles of temperature and pressure, the BSR depths effectively produce subseafloor geothermal information over a wide area without heat flow probe penetration or in-situ borehole temperature measurement that is fragmentary. In this study, we aim at calculating precise two-dimensional shallow thermal structure. First, we investigate detailed distribution of the BSRs in the Nankai area ranging from offshore Tokai to Hyuga using two-dimensional multi-channel seismic reflection data. The BSR depths are then forwarded to estimate heat flow values. Second, we use a simple two-dimensional thermal modeling of Blackwell et al. [1980] that takes into account topographical effects of the seafloor roughness. We also employ additional boundary conditions constrained by seafloor temperature and the heat flow estimated from BSR depths. In order to confirm reliability of the modeled thermal structure, we additionally estimate the base of gas hydrate stability zone which is proved to almost equal to observational BSR depths. We find in the modeled thermal structure that the convex portions that are subject to cooling by cold bottom water, while depressions are less subject to the cooling from observational BSRs and theoretical calculation. The thermal structure gained here provides essential data for seismic simulations in subduction zones and for laboratory experiments as

  9. Bedding material affects mechanical thresholds, heat thresholds and texture preference

    PubMed Central

    Moehring, Francie; O’Hara, Crystal L.; Stucky, Cheryl L.

    2015-01-01

    It has long been known that the bedding type animals are housed on can affect breeding behavior and cage environment. Yet little is known about its effects on evoked behavior responses or non-reflexive behaviors. C57BL/6 mice were housed for two weeks on one of five bedding types: Aspen Sani Chips® (standard bedding for our institute), ALPHA-Dri®, Cellu-Dri™, Pure-o’Cel™ or TEK-Fresh. Mice housed on Aspen exhibited the lowest (most sensitive) mechanical thresholds while those on TEK-Fresh exhibited 3-fold higher thresholds. While bedding type had no effect on responses to punctate or dynamic light touch stimuli, TEK-Fresh housed animals exhibited greater responsiveness in a noxious needle assay, than those housed on the other bedding types. Heat sensitivity was also affected by bedding as animals housed on Aspen exhibited the shortest (most sensitive) latencies to withdrawal whereas those housed on TEK-Fresh had the longest (least sensitive) latencies to response. Slight differences between bedding types were also seen in a moderate cold temperature preference assay. A modified tactile conditioned place preference chamber assay revealed that animals preferred TEK-Fresh to Aspen bedding. Bedding type had no effect in a non-reflexive wheel running assay. In both acute (two day) and chronic (5 week) inflammation induced by injection of Complete Freund’s Adjuvant in the hindpaw, mechanical thresholds were reduced in all groups regardless of bedding type, but TEK-Fresh and Pure-o’Cel™ groups exhibited a greater dynamic range between controls and inflamed cohorts than Aspen housed mice. PMID:26456764

  10. Tubulin cytoskeleton in elongation zone of Arabidopsis root is affected by clinorotation

    NASA Astrophysics Data System (ADS)

    Shevchenko, G.; Kalinina, Ya.; Kordyum, E.

    Our aim is to find out how clinorotation influences root growth For this purpose we followed the dynamics of tubulin cytoskeleton cortical and endoplasmic microtubules in cells from elongation zone of Arabidopsis roots transfected with GFP-MAP4 3 day old seedlings In distal part of elongation zone in epidermal cells mainly distinct endoplasmic microtubules were observed Prominent cortical microtubules start to be evident in cells in central elongation zone Under clinorotation clusters formed by MAP4 appear in all parts of elongation zone evidencing that microtubule arrangement is somehow distorted there Application of cytochalasin D which disrupts proper functioning of actin cytoskeleton in controls affected mainly the endoplasmic microtubules in cells with isotropic growth where MAP4 was clustered Under clinorotation disruption of actin cytoskeleton by cytochalasin D caused appearance of MAP4 clusters in cells growing anisotropically In those cells cortical microtubules are affected as well as endoplasmic Due to the fact that cortical microtubules are responsible for ordered growth of plant cell and are arranged into a robust structure change of their organization under clinorotation could impact cell growth This proves that cells in elongation zone switching their growth mode from isotropic to anisotropic are rather sensitive to altered gravity The fact that more severe distortion of cortical microtubules was noted in cells with damaged actin microfilaments proves mutually related functioning of actin and tubulin cytoskeletons under clinorotation

  11. Mantle convection with continental drift and heat source around the mantle transition zone

    NASA Astrophysics Data System (ADS)

    Ichikawa, H.; Kameyama, M.; Kawai, K.

    2012-12-01

    Geological studies have suggested that significant amount of granitic crustal materials have been lost from the surface by the delamination (~1.1 km^3/yr) [1], continental collision (~0.4-0.7 km^3/yr) [1, 2], and subduction at ocean-margin (~2.5-3 km^3/yr) [1, 2]. At ocean-margin subduction zones, most of the granitic materials subducted from the surface are expected to be conveyed through subduction channels by viscous drag to 270km depth [Ichikawa el al., in revision]. If so, then the subducted crustal materials might be expected to be trapped in the mid-mantle owing to the density difference from peridotitic materials induced by the phase transition from coesite to stishovite at 270km depth. In other words, strong heat source materials are most likely to be accumulated around the mantle transition zone, at least, near the plate subduction zones. In this study, we conducted two-dimensional numerical experiments of mantle convection with continental drift and a heat source placed around the mantle transition zone, in order to study the effect of the subducted granitic materials drifting around the mantle transition zone. The simulations deal with a time-dependent convection of fluid under the extended Boussinesq approximation in a model of a two-dimensional rectangular box of 2900km height and 11600km width, where a continent and heat source is imposed. We found that the addition of the heat source considerably reduces the time scale of continental drift. In the absence of the heat source, the resulting time scale is too long compared with that of the so-called supercontinent cycle, where the breakup is induced from a plume generated by an insulating effect of the continent. The heat source also causes massive mechanical mixing especially on the upper mantle. The result suggests that the heat source drifting around mantle transition zone can be a possible candidate inducing the supercontinent cycle in an appropriate time scale. [1] Clift, P. D., P. Vannucchi, and

  12. Influence of controlling vibrations on heat transfer in floating zone crystal growth*

    NASA Astrophysics Data System (ADS)

    Fedyushkin, A. I.

    The crystal growth processes of monocrystals are strongly vibrational sensitive systems and in particular it concerns to a floating zone method as presence of a free surface and two fronts of crystallization and melting that aggravate it The given work is devoted to numerical investigations of the influence of controlling vibrations on heat transfer during crystal growth by floating zone technique Normal and weightless environment conditions are considered Mathematical simulation is performed on the numerical solutions of basis unsteady Navier-Stokes equations for incompressible fluid flows and energy equation 2D axisymmetric geometry was used in model Marangoni convection and radiation condition on the curvature free surface were taken in account The calculations of the shape of a free surface of a liquid zone and influences on it of a corner of wetting force of weight and size of factor of a superficial tension are carried out The simulations of convective heat transfer for real curvature free surface of a liquid zone with and without the taking into account of the following factors parameters of radiation rotations natural and Marangoni convection and vibrations are carried out The given calculations are carried out for semiconductors melts with Prandtl number Pr 1 and for oxides Pr 1 The influence of vibrations of a crystal on melt flow and on the wide of dynamic and thermal boundary layers at melt-crystal interface is studied The action of vibrations on an enhancement of heat fluxes at the melt crystal interface is shown

  13. High Resolution Thermal Model and Heat Flow along the Washington Margin of the Cascadia Subduction Zone

    NASA Astrophysics Data System (ADS)

    Salmi, M.; Harris, R. N.; Johnson, H. P.; Solomon, E. A.

    2015-12-01

    Understanding the temperature distribution along an active subducting plate interface improves our understanding of subduction zone dynamics and seismic hazards. The temperature dependence of the locked zone is an important tool in identifying the region of stress accumulation along the subducting plate. The temperature at the up-dip limit of the seismic zone typically ranges from 100-150°C and the down-dip limit is a transition zone between 350°C and 450°C. In July 2012, Multi-Channel Seismic (MCS) data was collected using the R/V Langseth along nine profiles perpendicular to the accretionary wedge offshore Grays Harbor, Washington. The MCS lines extend from seaward of the deformation front to the continental shelf. In August 2013, we made seafloor heat flow measurements using a violin bow probe, thermal blankets and the Jason heat flow probe. These data show mean heat flow values of 110 mW/m2 over the incoming plate, 30 mW/m2 at the first deformation ridge, and mean of 100 mW/m2 over the lower accretionary wedge terrace. These measurements were co-located with two MCS profiles allowing for direct comparison with Bottom Simulating Reflectors (BSRs) that provide heat flow along all MCS lines from the deformation front to the methane hydrate stability depth at roughly 500 m. BSR-derived heat flow decreases from 90 mW/m2 at the deformation front to 60 mW/m2 beyond 60 km landward of the deformation front lower than consistent with our heat flow measurements, implying active upward diffuse fluid flow. Seismic velocities from MCS data provide an estimate of porosity and thermal conductivity of the underlying sediments providing the thermal parameters for a 2D model. Local but substantial heat flow anomalies likely reflect advective heat transfer within the shallow portion of the accretionary wedge. Preliminary modeling results indicate an incoming oceanic plate temperature of 215°C, potentially placing the up-dip limit of the seismogenic zone at the deformation

  14. Even extreme heat cannot affect the SP-ablator

    NASA Astrophysics Data System (ADS)

    Stoclfleth, Holger; Knabe, Helmut; Wahl, Juergen; Haug, Tilman

    A heat-protection system that was successfully tested in a plasma wind tunnel is described. The system is capable of withstanding extreme short-term heat loads when reentering the atmosphere. The surface-protected (SP) ablator exhibits significant increase in the efficiency of the cooling effect and dynamic pressure resistance due to a ceramic matrix composite layer that protects its surface.

  15. Thermal affected zone obtained in machining steel XC42 by high-power continuous CO 2 laser

    NASA Astrophysics Data System (ADS)

    Jebbari, Neila; Jebari, Mohamed Mondher; Saadallah, Faycal; Tarrats-Saugnac, Annie; Bennaceur, Raouf; Longuemard, Jean Paul

    2008-09-01

    A high-power continuous CO 2 laser (4 kW) can provide energy capable of causing melting or even, with a special treatment of the surface, vaporization of an XC42-steel sample. The laser-metal interaction causes an energetic machining mechanism, which takes place according to the assumption that the melting front precedes the laser beam, such that the laser beam interacts with a preheated surface whose temperature is near the melting point. The proposed model, obtained from the energy balance during the interaction time, concerns the case of machining with an inert gas jet and permits the calculation of the characteristic parameters of the groove according to the characteristic laser parameters (absorbed laser energy and impact diameter of the laser beam) and allows the estimation of the quantity of the energy causing the thermal affected zone (TAZ). This energy is equivalent to the heat quantity that must be injected in the heat propagation equation. In the case of a semi-infinite medium with fusion temperature at the surface, the resolution of the heat propagation equation gives access to the width of the TAZ.

  16. Identification of dominating factors affecting vadose zone vulnerability by a simulation method

    PubMed Central

    Li, Juan; Xi, Beidou; Cai, Wutian; Yang, Yang; Jia, Yongfeng; Li, Xiang; Lv, Yonggao; Lv, Ningqing; Huan, Huan; Yang, Jinjin

    2017-01-01

    The characteristics of vadose zone vulnerability dominating factors (VDFs) are closely related to the migration and transformation mechanisms of contaminants in the vadose zone, which directly affect the state of the contaminants percolating to the groundwater. This study analyzes the hydrogeological profile of the pore water regions in the vadose zone, and conceptualizes the vadose zone as single lithologic, double lithologic, or multi lithologic. To accurately determine how the location of the pollution source influences the groundwater, we classify the permeabilities (thicknesses) of different media into clay-layer and non-clay-layer permeabilities (thicknesses), and introduce the maximum pollution thickness. Meanwhile, the physicochemical reactions of the contaminants in the vadose zone are represented by the soil adsorption and soil degradability. The VDFs are determined from the factors and parameters in groundwater vulnerability assessment. The VDFs are identified and sequenced in simulations and a sensitivity analysis. When applied to three polluted sites in China, the method improved the weighting of factors in groundwater vulnerability assessment, and increased the reliability of predicting groundwater vulnerability to contaminants. PMID:28387232

  17. Oxidative Activity of Heated Coal Affected by Antypirogens

    NASA Astrophysics Data System (ADS)

    Torosyan, V. F.; Torosyan, E. S.; Borovikov, I. F.; Yakutova, V. A.

    2016-04-01

    The effect of antypirogens on chemical activity of heated coal is studied. It is proved that ammonium sulfate, calcium phosphate, calcium chloride, calcium nitrate and acid fluoride are the most effective antypirogens.

  18. Characterizing multiple timescales of stream and storage zone interaction that affect solute fate and transport in streams

    USGS Publications Warehouse

    Choi, J.; Harvey, J.W.; Conklin, M.H.

    2000-01-01

    The fate of contaminants in streams and rivers is affected by exchange and biogeochemical transformation in slowly moving or stagnant flow zones that interact with rapid flow in the main channel. In a typical stream, there are multiple types of slowly moving flow zones in which exchange and transformation occur, such as stagnant or recirculating surface water as well as subsurface hyporheic zones. However, most investigators use transport models with just a single storage zone in their modeling studies, which assumes that the effects of multiple storage zones can be lumped together. Our study addressed the following question: Can a single-storage zone model reliably characterize the effects of physical retention and biogeochemical reactions in multiple storage zones? We extended an existing stream transport model with a single storage zone to include a second storage zone. With the extended model we generated 500 data sets representing transport of nonreactive and reactive solutes in stream systems that have two different types of storage zones with variable hydrologic conditions. The one storage zone model was tested by optimizing the lumped storage parameters to achieve a best fit for each of the generated data sets. Multiple storage processes were categorized as possessing I, additive; II, competitive; or III, dominant storage zone characteristics. The classification was based on the goodness of fit of generated data sets, the degree of similarity in mean retention time of the two storage zones, and the relative distributions of exchange flux and storage capacity between the two storage zones. For most cases (> 90%) the one storage zone model described either the effect of the sum of multiple storage processes (category I) or the dominant storage process (category III). Failure of the one storage zone model occurred mainly for category II, that is, when one of the storage zones had a much longer mean retention time (t(s) ratio > 5.0) and when the dominance of

  19. Heat transfer through a solar pond nonconvective zone of recycled glass

    SciTech Connect

    Ketchum, D. E.

    1981-01-01

    The heat transfer through a recycled glass/water porous medium is examined experimentally to determine the medium's effectiveness as a nonconvective zone in a solar pond. Temperature distributions within clear bottle or broken glass/water mediums are studied with heated from above, and heated from below orientations. A small solar pond of glass bottles as well as a numerical simulation of a glass sphere solar pond are also investigated. Results of the experimental study show that convection was not suppressed by using bottles during bottom heating and indicate that stagnation will only occur with very small glass fragments. The computer simulation further indicated that even with perfect transmittance through the medium, pond efficiency will be far less than for a salt gradient pond. The small pond tests show no temperature gradient (indicating little stagnation), show little radiation transmittance through the medium (less than 10% for a .4 meter pond), and confirm the conclusion that a glass bottle or broken glass/water medium is unsuitable as a solar pond nonconvective zone.

  20. Control schemes for an industrial rotary calciner with a heat shield around the combustion zone

    SciTech Connect

    Ciftci, S.; Kim, N.K.

    1999-03-01

    Soda ash (sodium carbonate) is produced by calcining natural trona ore (sodium sesquicarbonate) in rotary calciners. Shell overheating, the consequent deformation of the calciner shell, and heat loss are frequently encountered problems during this operation. Installation of a concentric, metallic heat shield around the calciner`s combustion zone can help to reduce the shell temperature and recover some of the energy that would otherwise be lost. Another problem often encountered is the deterioration of product quality when the system inputs deviate from their design rates. A mathematical model of the calciner with a heat shield is used to design different control schemes in order to maintain the product quality. Performance of the designed control schemes is demonstrated via computer simulation.

  1. Electron heating within interaction zones of simple high-speed solar wind streams

    NASA Technical Reports Server (NTRS)

    Feldman, W. C.; Asbridge, J. R.; Bame, S. J.; Gosling, J. T.; Lemons, D. S.

    1978-01-01

    In the present paper, electron heating within the high-speed portions of three simple stream-stream interaction zones is studied to further our understanding of the physics of heat flux regulation in interplanetary space. To this end, the thermal signals present in the compressions at the leading edges of the simple high-speed streams are analyzed, showing that the data are inconsistent with the Spitzer conductivity. Instead, a polynomial law is found to apply. Its implication concerning the mechanism of interplanetary heat conduction is discussed, and the results of applying this conductivity law to high-speed flows inside of 1 AU are studied. A self-consistent model of the radial evolution of electrons in the high-speed solar wind is proposed.

  2. Does human pressure affect the community structure of surf zone fish in sandy beaches?

    NASA Astrophysics Data System (ADS)

    Costa, Leonardo Lopes; Landmann, Júlia G.; Gaelzer, Luiz R.; Zalmon, Ilana R.

    2017-01-01

    Intense tourism and human activities have resulted in habitat destruction in sandy beach ecosystems with negative impacts on the associated communities. To investigate whether urbanized beaches affect surf zone fish communities, fish and their benthic macrofaunal prey were collected during periods of low and high human pressure at two beaches on the Southeastern Brazilian coast. A BACI experimental design (Before-After-Control-Impact) was adapted for comparisons of tourism impact on fish community composition and structure in urbanized, intermediate and non-urbanized sectors of each beach. At the end of the summer season, we observed a significant reduction in fish richness, abundance, and diversity in the high tourist pressure areas. The negative association between visitors' abundance and the macrofaunal density suggests that urbanized beaches are avoided by surf zone fish due to higher human pressure and the reduction of food availability. Our results indicate that surf zone fish should be included in environmental impact studies in sandy beaches, including commercial species, e.g., the bluefish Pomatomus saltatrix. The comparative results from the less urbanized areas suggest that environmental zoning and visitation limits should be used as effective management and preservation strategies on beaches with high conservation potential.

  3. Performance processes within affect-related performance zones: a multi-modal investigation of golf performance.

    PubMed

    van der Lei, Harry; Tenenbaum, Gershon

    2012-12-01

    Individual affect-related performance zones (IAPZs) method utilizing Kamata et al. (J Sport Exerc Psychol 24:189-208, 2002) probabilistic model of determining the individual zone of optimal functioning was utilized as idiosyncratic affective patterns during golf performance. To do so, three male golfers of a varsity golf team were observed during three rounds of golf competition. The investigation implemented a multi-modal assessment approach in which the probabilistic relationship between affective states and both, performance process and performance outcome, measures were determined. More specifically, introspective (i.e., verbal reports) and objective (heart rate and respiration rate) measures of arousal were incorporated to examine the relationships between arousal states and both, process components (i.e., routine consistency, timing), and outcome scores related to golf performance. Results revealed distinguishable and idiosyncratic IAPZs associated with physiological and introspective measures for each golfer. The associations between the IAPZs and decision-making or swing/stroke execution were strong and unique for each golfer. Results are elaborated using cognitive and affect-related concepts, and applications for practitioners are provided.

  4. Atmospheric composition affects heat- and mass-transfer processes

    NASA Technical Reports Server (NTRS)

    Blakely, R. L.; Nelson, W. G.

    1970-01-01

    For environmental control system functions sensitive to atmospheric composition, components are test-operated in helium-oxygen and nitrogen-oxygen mixtures, pure oxygen, and air. Transient heat- and mass-transfer tests are conducted for carbon dioxide adsorption on molecular sieve and for water vapor adsorption on silica gel.

  5. Ion heating by strong electrostatic ion cyclotron turbulence. [in auroral zone

    NASA Technical Reports Server (NTRS)

    Lysak, R. L.; Hudson, M. K.; Temerin, M.

    1980-01-01

    A theory of the ion heating due to electrostatic ion cyclotron (EIC) waves in the auroral zone is presented. Due to the slowly convecting nature of the EIC mode, quasi-linear plateau formation cannot stabilize the waves, and growth occurs until the nonlinear mechanisms of ion resonance broadening and electron trapping provide saturation. The large amplitude and coherent nature of the resulting wave imply that quasi-linear theory provides only a lower limit to the ion heating. An upper bound on the heating rate is derived using a time-average model of ion dynamics in the coherent waves. The effects of ion heating in the presence of the magnetic gradient force and parallel electric fields are considered, with the result that perpendicular energies over 100 eV are easily attainable from a 1 eV source plasma. Perpendicular heating in the absence of a parallel electric field yields conical ion distributions, which in the presence of an electric field become field-aligned beams.

  6. Serum heat inactivation affects protein corona composition and nanoparticle uptake.

    PubMed

    Lesniak, Anna; Campbell, Abigail; Monopoli, Marco P; Lynch, Iseult; Salvati, Anna; Dawson, Kenneth A

    2010-12-01

    Nanoparticles are of an appropriate size to interact with cells, and are likely to use a range of cellular machinery for internalisation and trafficking to various sub-cellular compartments. It is now understood that once in contact with biological fluids, the nanoparticle surface gets covered by a highly specific layer of proteins, forming the nanoparticle protein corona. This protein layer is stable for times longer than the typical time scale of nanoparticle import, and thus can impact on particle uptake and trafficking inside the cells. In this work, the effect of the corona composition on nanoparticle uptake has been investigated, by studying the impact of serum heat inactivation and complement depletion on the load of nanoparticles accumulated inside the cell. For the same material and nanoparticle size, cellular uptake was found to be significantly different when the nanoparticles were dispersed in medium where the serum was heat inactivated or not heat inactivated, even for non-specialized cells, suggesting that different sera can lead to different nanoparticle doses. The fact that uptake was correlated with the amount of protein bound into the nanoparticle corona suggests the need for commonly agreed dispersion protocols for in vitro nanoparticle-cell studies.

  7. Laser-Heated Floating Zone Production of Single-Crystal Fibers

    NASA Technical Reports Server (NTRS)

    Ritzert, Frank; Westfall, Leonard

    1996-01-01

    This report describes how a laser-heated floating zone apparatus can be used to investigate single-crystal fibers of various compositions. A feedrod with a stoichiometric composition of high-purity powders was connected to a pedestal and fed into a laser scan where it combined with a single-crystal fiber seed. A molten zone was formed at this junction. As the feedrod was continuously fed into the laser scan, a single-crystal fiber of a prescribed orientation was withdrawn from the melt. The resultant fibers, whose diameters ranged from 100 to 250 gm, could then be evaluated on the basis of their growth behavior, physical properties, mechanical properties, and fiber perfection.

  8. Determination of rainfall and condensational heating in the South Pacific convergence zone during FGGE SOP-1

    NASA Technical Reports Server (NTRS)

    Robertson, F. R.

    1984-01-01

    The role of cloud related diabatic processes in maintaining the structure of the South Pacific Convergence Zone is discussed. The method chosen to evaluate the condensational heating is a diagnostic cumulus mass flux technique which uses GOES digital IR data to characterize the cloud population. This method requires as input an estimate of time/area mean rainfall rate over the area in question. Since direct observation of rainfall in the South Pacific is not feasible, a technique using GOES IR data is being developed to estimate rainfall amounts for a 2.5 degree grid at 12h intervals.

  9. Does the Heat Island Effect Affect Lake Chabot

    NASA Astrophysics Data System (ADS)

    Singh, K. A.; Mock, Y.; Pun, C.

    2014-12-01

    Lake Chabot is a backup water supply source and it is important to know if the water is healthy because California is experiencing a drought. To check the quality of the water we used a submersible, waterproof thermometer to measure the temperature of the water at different depths. We hypothesized that the heat-island effect would cause the runoff from the surrounding developed areas to be warmer. This is because paving roads causes areas to become impermeable and absorb heat. Water runs off these impermeable surfaces, absorbing heat from the ground and enters larger bodies of water via stream. To locate streams we used a topography map. We located close lines followed by lines that were farther apart and then once again followed by close lines. This indicates that there is a concave area between two high points, allowing water to possibly flow through. We found that areas where the water came from highly populated areas were warmer. The increase in temperature was shown throughout all depths of the water at each site that was measured. The temperature throughout the lake was in between 19°C and 25°C. This warm temperature makes it hard for gases to mix. The lower the dissolved oxygen level, the less desirable it is for a variety of organisms to survive. Higher temperatures also increase bacterial growth and can causes water to be unhealthy. This indicates that the water at Lake Chabot is not suitable for human consumption and should not be considered a suitable backup water source for our area.

  10. Determining the locus of a processing zone in an oil shale retort by effluent off gas heating value

    SciTech Connect

    Cha, C.Y.

    1981-07-21

    A processing zone advances through a fragmented permeable mass of particles containing oil shale in an in situ oil shale retort in a subterranean formation containing oil shale. The retort has an effluent gas passing therefrom. The effluent gas has a heating value which is dependent on the kerogen content of the oil shale then in contact with the processing zone. To determine the locus of the processing zone, the formation is assayed at selected locations in the retort for kerogen content before processing the selected locations, and effluent gas from the retort is monitored for its heating value.

  11. Zoning of the territory of Russia by the effectiveness of low-potential heat of the ground and atmospheric air for heating buildings

    NASA Astrophysics Data System (ADS)

    Vasilyev, G. P.; Kolesova, M. V.; Gornov, V. F.; Yurchenko, I. A.

    2016-06-01

    The article represents the results of researches to zone the territory of Russia and Europe division into districts of by efficiency of using for the heat supply of buildings of low-potential thermal energy of ground and free air and their combination. While modeling the heat regime of geothermal HPS in climatic conditions of different regions of the territory of Russia, the influence of the long-term extraction of geothermal heat energy on the ground heat regime has been taken into account as well as the influence of phase transitions of pore moisture in ground on the efficiency of operation of geothermal heat-pump heat-supply systems. Also considered were the sinking of temperatures of ground massif by long-term extraction of the heat energy from the ground as calculation parameters of the heat energy from the ground, and as calculation parameters of ground massif temperatures.

  12. Novel thermal effect at nanoshell heating by pulsed laser irradiation: hoop-shaped hot zone formation.

    PubMed

    Avetisyan, Yuri A; Yakunin, Alexander N; Tuchin, Valery V

    2012-10-01

    Photonic nanotechnologies have good perspectives to be widely used in biophotonics. In this study we have developed an approach for calculation of nanoparticle temperature field accounting for absorbed local intensity at pulse laser radiation of composite spherical nanoparticles (nanoshells). This approach allowed us to analyze spatial inhomogeneities of light field diffracted into a nanoshell and corresponding distribution of the absorption energy and to provide numerical solution of time-dependent heat conduction equation accounting for corresponding spatially inhomogeneous distribution of heating sources. We were able to predict the appearance of a novel thermal effect - hoop-shaped hot zone on the nanoshell surface. The observed effect has potential applications in cell biology and medicine for controlled cell optoporation and nanosurgery, as well as cancer cell killing.

  13. Factors affecting the catalytic oligomerization of methane via microwave heating

    NASA Astrophysics Data System (ADS)

    Conde, Luis Daniel

    Catalytic microwave heating has been used as a method for the oligomerization of methane to higher hydrocarbons. Many catalysts were tested in this reaction. Nickel powder, raney nickel, iron powder and activated carbon were the most active and efficient catalysts for the production of higher hydrocarbons. When helium was used as a diluent gas and the applied power was optimized, the selectivities were controlled to the most desired products. In general, the most abundant products for all the experiments were C2s. Iron powder was active only at high power (1130 W). At these conditions acetylene was avoided and ethylene and ethane were produced in the same proportion. Activated carbon catalysts with helium as diluent led to a selectivity towards benzene up to 33%. Some manganese oxides such as OMS-1, OMS-2 and MnO2 (dielectric constant, epsilon ≈ 104) were not active in these reactions. These data suggest that the dielectric constant is not the most important factor in the oligomerization of methane via microwave heating. Conversion and activities of these materials are not proportionally related to the surface area of the catalysts. Higher catalytic activity was observed for Raney nickel than for regular nickel powder. The maximum conversion obtained was 24% at 400 W and 10 min of irradiation time. For regular nickel powder that conversion can be achieved only after 700 W of power and more than 20 min of reaction. BET surface area, Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy, and Temperature-Programmed Desorption and Reduction analysis were performed to characterize the catalyst before and after reaction. Deactivation of Raney nickel by fouling and sintering was observed after 500 W and/or 15 min of reaction. The effect of microwave radiation frequency on activity and product distribution for methane oligomerization has been studied. Nickel, iron, and activated carbon catalysts were used in these studies. Experiments were done with pure methane

  14. High Heating Rates Affect Greatly the Inactivation Rate of Escherichia coli

    PubMed Central

    Huertas, Juan-Pablo; Aznar, Arantxa; Esnoz, Arturo; Fernández, Pablo S.; Iguaz, Asunción; Periago, Paula M.; Palop, Alfredo

    2016-01-01

    Heat resistance of microorganisms can be affected by different influencing factors. Although, the effect of heating rates has been scarcely explored by the scientific community, recent researches have unraveled its important effect on the thermal resistance of different species of vegetative bacteria. Typically heating rates described in the literature ranged from 1 to 20°C/min but the impact of much higher heating rates is unclear. The aim of this research was to explore the effect of different heating rates, such as those currently achieved in the heat exchangers used in the food industry, on the heat resistance of Escherichia coli. A pilot plant tubular heat exchanger and a thermoresistometer Mastia were used for this purpose. Results showed that fast heating rates had a deep impact on the thermal resistance of E. coli. Heating rates between 20 and 50°C/min were achieved in the heat exchanger, which were much slower than those around 20°C/s achieved in the thermoresistometer. In all cases, these high heating rates led to higher inactivation than expected: in the heat exchanger, for all the experiments performed, when the observed inactivation had reached about seven log cycles, the predictions estimated about 1 log cycle of inactivation; in the thermoresistometer these differences between observed and predicted values were even more than 10 times higher, from 4.07 log cycles observed to 0.34 predicted at a flow rate of 70 mL/min and a maximum heating rate of 14.7°C/s. A quantification of the impact of the heating rates on the level of inactivation achieved was established. These results point out the important effect that the heating rate has on the thermal resistance of E. coli, with high heating rates resulting in an additional sensitization to heat and therefore an effective food safety strategy in terms of food processing. PMID:27563300

  15. High Heating Rates Affect Greatly the Inactivation Rate of Escherichia coli.

    PubMed

    Huertas, Juan-Pablo; Aznar, Arantxa; Esnoz, Arturo; Fernández, Pablo S; Iguaz, Asunción; Periago, Paula M; Palop, Alfredo

    2016-01-01

    Heat resistance of microorganisms can be affected by different influencing factors. Although, the effect of heating rates has been scarcely explored by the scientific community, recent researches have unraveled its important effect on the thermal resistance of different species of vegetative bacteria. Typically heating rates described in the literature ranged from 1 to 20°C/min but the impact of much higher heating rates is unclear. The aim of this research was to explore the effect of different heating rates, such as those currently achieved in the heat exchangers used in the food industry, on the heat resistance of Escherichia coli. A pilot plant tubular heat exchanger and a thermoresistometer Mastia were used for this purpose. Results showed that fast heating rates had a deep impact on the thermal resistance of E. coli. Heating rates between 20 and 50°C/min were achieved in the heat exchanger, which were much slower than those around 20°C/s achieved in the thermoresistometer. In all cases, these high heating rates led to higher inactivation than expected: in the heat exchanger, for all the experiments performed, when the observed inactivation had reached about seven log cycles, the predictions estimated about 1 log cycle of inactivation; in the thermoresistometer these differences between observed and predicted values were even more than 10 times higher, from 4.07 log cycles observed to 0.34 predicted at a flow rate of 70 mL/min and a maximum heating rate of 14.7°C/s. A quantification of the impact of the heating rates on the level of inactivation achieved was established. These results point out the important effect that the heating rate has on the thermal resistance of E. coli, with high heating rates resulting in an additional sensitization to heat and therefore an effective food safety strategy in terms of food processing.

  16. Health in the hot zone - How could global warming affect humans?

    SciTech Connect

    Monastersky, R.

    1996-04-06

    A soon-to-be-released report from the World Health Organization examines the health effects of global warming, calling climate change one of the largest public health challenges for the upcoming century. The issue extends beyond tropical illness: deaths caused directly by heat, dwindling agricultural yields etc. could all affect human health. This article looks at the following health related effects and gives an overview of the scientific information available on each: temperature and mortality; tropical trouble, including vecorborne diseases and increase in susceptable populations; and waterborne problems such as cholera, harmful algal bloomes, food shortages.

  17. Microwave thermal imaging: initial in vivo experience with a single heating zone.

    PubMed

    Meaney, P M; Fanning, M W; Paulsen, K D; Lit, D; Pendergrass, S A; Fang, Q; Moodie, K L

    2003-01-01

    The deployment of hyperthermia as a routine adjuvant to radiation or chemotherapy is limited largely by the inability to devise treatment plans which can be monitored through temperature distribution feedback during therapy. A non-invasive microwave tomographic thermal imaging system is currently being developed which has previously exhibited excellent correlation between the recovered electrical conductivity of a heated zone and its actual temperature change during phantom studies. To extend the validation of this approach in vivo, the imaging system has been re-configured for small animal experiments to operate within the bore of a CT scanner for anatomical and thermometry registration. A series of 5-7 day old pigs have been imaged during hyperthermia with a monopole antenna array submerged in a saline tank where a small plastic tube surgically inserted the length of the abdomen has been used to create a zone of heated saline at pre-selected temperatures. Tomographic microwave data over the frequency range of 300-1000 MHz of the pig abdomen in the plane perpendicular to the torso is collected at regular intervals after the tube saline temperatures have settled to the desired settings. Images are reconstructed over a range of operating frequencies. The tube location is clearly visible and the recovered saline conductivity varies linearly with the controlled temperature values. Difference images utilizing the baseline state prior to heating reinforces the linear relationship between temperature and imaged saline conductivity. Demonstration of in vivo temperature recovery and correlation with an independent monitoring device is an important milestone prior to clinical integration of this non-invasive imaging system with a thermal therapy device.

  18. Modelling of transient river - aquifer exchange using pressure head and heat measurements: the hyporheic zone's dimension

    NASA Astrophysics Data System (ADS)

    Nuetzmann, Gunnar; Christian, Levers; Jörg, Lewandowski

    2010-05-01

    Water exchange processes in the floodplain of a lowland groundwater-surface water system are studied on the basis of a study site near Freienbrink, NE Germany. The surface water boundaries of this site are formed by an oxbow and the current bed of the river Spree, section Müggelspree. Surface and ground water levels and water temperatures were collected in 12 piezometers and 2 recording stage gauges of a 300 m long transect throughout a one-year-period. Due to water level fluctuations alternation of infiltration and exfiltration occurred. However, most of the time groundwater flux is directed into the river Spree and, river water infiltration events into the aquifer are usually short and of minor importance. Due to clogging of the oxbow bed with a mud layer of different thickness the hydraulic contact between the oxbow and the adjacent aquifer is heterogeneously distributed and partially marginal. These features are modelled quantitatively using SUTRA in order to simulate coupled ground water flow and heat transport. A two-dimensional vertical modelling approach along the piezometer transect is developed to study exchange processes close to the surface water bodies more in detail in order to quantify the hyporheic fluxes of both river sections and to identify the directions and quantities of mass and heat fluxes. With the results the following questions will be answered: (1) It is possible to identify and to quantify the hydraulic processes (in- and exfiltration) between both river sections and the aquifer? (2) How fast does the exchange between the surface water and the aquifer occur? (3) Is there a hyporheic zone between the river sections and the aquifer, where groundwater and surface water are mixed, and how much water and heat will be transferred through this zones?

  19. Zones of impact around icebreakers affecting beluga whales in the Beaufort Sea.

    PubMed

    Erbe, C; Farmer, D M

    2000-09-01

    A software model estimating zones of impact on marine mammals around man-made noise [C. Erbe and D. M. Farmer, J. Acoust. Soc. Am. 108, 1327-1331 (2000)] is applied to the case of icebreakers affecting beluga whales in the Beaufort Sea. Two types of noise emitted by the Canadian Coast Guard icebreaker Henry Larsen are analyzed: bubbler system noise and propeller cavitation noise. Effects on beluga whales are modeled both in a deep-water environment and a near-shore environment. The model estimates that the Henry Larsen is audible to beluga whales over ranges of 35-78 km, depending on location. The zone of behavioral disturbance is only slightly smaller. Masking of beluga communication signals is predicted within 14-71-km range. Temporary hearing damage can occur if a beluga stays within 1-4 km of the Henry Larsen for at least 20 min. Bubbler noise impacts over the short ranges quoted; propeller cavitation noise accounts for all the long-range effects. Serious problems can arise in heavily industrialized areas where animals are exposed to ongoing noise and where anthropogenic noise from a variety of sources adds up.

  20. Heat shock applied early in sporulation affects heat resistance of Bacillus megaterium spores.

    PubMed

    Sedlák, M; Vinter, V; Adamec, J; Vohradský, J; Voburka, Z; Chaloupka, J

    1993-12-01

    Cells of Bacillus megaterium 27 were challenged by a 30-min heat shock at 45 degrees C during various sporulation stages and then shifted back to a temperature permissive for sporulation (27 degrees C), at which they developed spores. Heat shock applied at 120 min after the end of the exponential phase induced synthesis of heat shock proteins (HSPs) in the sporangia and delayed the inactivation of spores at 85 degrees C. Several HSPs, mainly HSP 70, could be detected in the cytoplasm of these spores. An analogous HSP, the main HSP induced by increased temperature during growth, belongs to the GroEL group according to its N-terminal sequence. The identity of this protein was confirmed by Western blot (immunoblot) analysis with polyclonal antibodies against B. subtilis GroEL. Sporangia treated by heat shock immediately or 240 min after exponential phase also synthesized HSPs, but none of them could be detected in the spores in an appreciable amount. These spores showed only a slightly increased heat resistance.

  1. Plant hybrid zones affect biodiversity: Tools for a genetic-based understanding of community structure

    SciTech Connect

    Whitham, T.G.; Martinsen, G.D.; Keim, P.; Floate, K.D.; Dungey, H.S. |; Potts, B.M.

    1999-03-01

    Plant hybrid zones are dynamic centers of ecological and evolutionary processes for plants and their associated communities. Studies in the wild and in gardens with synthetic crosses showed that hybrid eucalypts supports the greatest species richness and abundances of insect and fungal taxa. In an updated review of 152 case studies of taxa associated with diverse hybridizing systems, there were 43 (28%) cases of hybrids being more susceptible than their parent species, 7 (5%) resistant, 35 (23%) additive, 35 (23%) dominant, and 32 (21%) showed no response to hybridization. Thus, most taxa respond to hybrids in ways that result in equal or greater abundance, and hybrids tend to accumulate the taxa of their parent species. These studies suggest that genetic-based plant traits affect the distribution of many species and that the variation in hybrids can be used as tools to examine the genetic components of community structure and biodiversity.

  2. Enhancement and performance evaluation for heat transfer of air cooling zone for reduction system of sponge titanium

    NASA Astrophysics Data System (ADS)

    Wang, Wenhao; Wu, Fuzhong; Jin, Huixin

    2017-02-01

    Since the magnesiothermic reduction employed in current sponge titanium is a highly exothermic reaction, the TiCl4 feed rate is carried out slowly to keep a suitable temperature in reduction reactor, which accounts for an extremely low level of productivity and energy efficiency. In order to shorten the production cycle and improve the energy efficiency, an enhancing scheme is proposed to enhance the heat transfer of air cooling zone for reduction system. The air cooling zone and enhancing scheme are firstly introduced. And then, the heat transfer characteristics of cooling zone are obtained by theoretical analysis and experimental date without enhancing scheme. Finally, the enhancement is analyzed and evaluated. The results show that the fitting results of heat transfer coefficients can be used to evaluate the heat transfer enhancement of cooling zone. Heat sources temperatures have a limited decreasing, heat transfer rate increases obviously with the enhanced cooling, and the TiCl4 feed rate can be increased significantly by 9.61 %. And the measured and calculated results are good enough to meet the design requirements.

  3. Enhancement and performance evaluation for heat transfer of air cooling zone for reduction system of sponge titanium

    NASA Astrophysics Data System (ADS)

    Wang, Wenhao; Wu, Fuzhong; Jin, Huixin

    2016-05-01

    Since the magnesiothermic reduction employed in current sponge titanium is a highly exothermic reaction, the TiCl4 feed rate is carried out slowly to keep a suitable temperature in reduction reactor, which accounts for an extremely low level of productivity and energy efficiency. In order to shorten the production cycle and improve the energy efficiency, an enhancing scheme is proposed to enhance the heat transfer of air cooling zone for reduction system. The air cooling zone and enhancing scheme are firstly introduced. And then, the heat transfer characteristics of cooling zone are obtained by theoretical analysis and experimental date without enhancing scheme. Finally, the enhancement is analyzed and evaluated. The results show that the fitting results of heat transfer coefficients can be used to evaluate the heat transfer enhancement of cooling zone. Heat sources temperatures have a limited decreasing, heat transfer rate increases obviously with the enhanced cooling, and the TiCl4 feed rate can be increased significantly by 9.61 %. And the measured and calculated results are good enough to meet the design requirements.

  4. Root-zone acidity affects relative uptake of nitrate and ammonium from mixed nitrogen sources

    NASA Technical Reports Server (NTRS)

    Vessey, J. K.; Henry, L. T.; Chaillou, S.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1990-01-01

    Soybean plants (Glycine max [L.] Merr. cv Ransom) were grown for 21 days on 4 sources of N (1.0 mM NO3-, 0.67 mM NO3- plus 0.33 mM NH4+, 0.33 mM NO3- plus 0.67 mM NH4+, and 1.0 mM NH4+) in hydroponic culture with the acidity of the nutrient solution controlled at pH 6.0, 5.5, 5.0, and 4.5. Dry matter and total N accumulation of the plants was not significantly affected by N-source at any of the pH levels except for decreases in these parameters in plants supplied solely with NH4+ at pH 4.5. Shoot-to-root ratios increased in plants which had an increased proportion [correction of proporiton] of NH4(+)-N in their nutrient solutions at all levels of root-zone pH. Uptake of NO3- and NH4+ was monitored daily by ion chromatography as depletion of these ions from the replenished hydroponic solutions. At all pH levels the proportion of either ion that was absorbed increased as the ratio of that ion increased in the nutrient solution. In plants which were supplied with sources of NO3- plus NH4+, NH4+ was absorbed at a ratio of 2:1 over NO3- at pH 6.0. As the pH of the root-zone declined, however, NH4+ uptake decreased and NO3- uptake increased. Thus, the NH4+ to NO3- uptake ratio declined with decreases in root-zone pH. The data indicate a negative effect of declining root-zone pH on NH4+ uptake and supports a hypothesis that the inhibition of growth of plants dependent on NH4(+)-N at low pH is due to a decline in NH4+ uptake and a consequential limitation of growth by N stress.

  5. Flavor of oranges as impacted by abscission zone formation for trees affected by huanglongbing disease and Lasiodiploida infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trees affected by Huanglongbing (HLB) exhibit excessive fruit drop, which is exacerbated by secondary infection of the abscission zone by the fungus Lasiodiplodia. ‘Hamlin’ orange trees, both healthy and affected by HLB, Candidatus Liberibacter asiaticus (CLas, determined by Polymerase chain reactio...

  6. Developmental acclimation to low or high humidity conditions affect starvation and heat resistance of Drosophila melanogaster.

    PubMed

    Parkash, Ravi; Ranga, Poonam; Aggarwal, Dau Dayal

    2014-09-01

    Several Drosophila species originating from tropical humid localities are more resistant to starvation and heat stress than populations from high latitudes but mechanistic bases of such physiological changes are largely unknown. In order to test whether humidity levels affect starvation and heat resistance, we investigated developmental acclimation effects of low to high humidity conditions on the storage and utilization of energy resources, body mass, starvation survival, heat knockdown and heat survival of D. melanogaster. Isofemale lines reared under higher humidity (85% RH) stored significantly higher level of lipids and showed greater starvation survival hours but smaller in body size. In contrast, lines reared at low humidity evidenced reduced levels of body lipids and starvation resistance. Starvation resistance and lipid storage level were higher in females than males. However, the rate of utilization of lipids under starvation stress was lower for lines reared under higher humidity. Adult flies of lines reared at 65% RH and acclimated under high or low humidity condition for 200 hours also showed changes in resistance to starvation and heat but such effects were significantly lower as compared with developmental acclimation. Isofemale lines reared under higher humidity showed greater heat knockdown time and heat-shock survival. These laboratory observations on developmental and adult acclimation effects of low versus high humidity conditions have helped in explaining seasonal changes in resistance to starvation and heat of the wild-caught flies of D. melanogaster. Thus, we may suggest that wet versus drier conditions significantly affect starvation and heat resistance of D. melanogaster.

  7. Temperature and duration of heating of sunflower oil affect ruminal biohydrogenation of linoleic acid in vitro.

    PubMed

    Privé, F; Combes, S; Cauquil, L; Farizon, Y; Enjalbert, F; Troegeler-Meynadier, A

    2010-02-01

    Sunflower oil heated at 110 or 150 degrees C for 1, 3, or 6h was incubated with ruminal content in order to investigate the effects of temperature and duration of heating of oil on the ruminal biohydrogenation of linoleic acid in vitro. When increased, these 2 parameters acted together to decrease the disappearance of linoleic acid in the media by inhibiting the isomerization of linoleic acid, which led to a decrease in conjugated linoleic acids and trans-C18:1 production. Nevertheless, trans-10 isomer production increased with heating temperature, suggesting an activation of Delta(9)-isomerization, whereas trans-11 isomer production decreased, traducing an inhibition of Delta(12)-isomerization. The amount of peroxides generated during heating was correlated with the proportions of biohydrogenation intermediates so that they might explain, at least in part, the observed effects. The effects of heating temperature and duration on ruminal bacteria community was assessed using capillary electrophoresis single-strand conformation polymorphism. Ruminal bacterial population significantly differed according to heating temperature, but was not affected by heating duration. Heating of fat affected ruminal biohydrogenation, at least in part because of oxidative products generated during heating, by altering enzymatic reactions and bacterial population.

  8. Numerical simulations of the impact of seasonal heat storage on source zone emission in a TCE contaminated aquifer

    NASA Astrophysics Data System (ADS)

    Popp, Steffi; Beyer, Christof; Dahmke, Andreas; Bauer, Sebastian

    2016-04-01

    In urban regions, with high population densities and heat demand, seasonal high temperature heat storage in the shallow subsurface represents an attractive and efficient option for a sustainable heat supply. In fact, the major fraction of energy consumed in German households is used for room heating and hot water production. Especially in urbanized areas, however, the installation of high temperature heat storage systems is currently restricted due to concerns on negative influences on groundwater quality caused e.g. by possible interactions between heat storages and subsurface contaminants, which are a common problem in the urban subsurface. Detailed studies on the overall impact of the operation of high temperature heat storages on groundwater quality are scarce. Therefore, this work investigates possible interactions between groundwater temperature changes induced by heat storage via borehole heat exchangers and subsurface contaminations by numerical scenario analysis. For the simulation of non-isothermal groundwater flow, and reactive transport processes the OpenGeoSys code is used. A 2D horizontal cross section of a shallow groundwater aquifer is assumed in the simulated scenario, consisting of a sandy sediment typical for Northern Germany. Within the aquifer a residual trichloroethene (TCE) contaminant source zone is present. Temperature changes are induced by a seasonal heat storage placed within the aquifer with scenarios of maximum temperatures of 20°C, 40°C and 60°C, respectively, during heat injection and minimum temperatures of 2°C during heat extraction. In the scenario analysis also the location of the heat storage relative to the TCE source zone and plume was modified. Simulations were performed in a homogeneous aquifer as well as in a set of heterogeneous aquifers with hydraulic conductivity as spatially correlated random fields. In both cases, results show that the temperature increase in the heat plume and the consequential reduction of water

  9. Implications of Shear Heating and Fracture Zones for Ridge Formation on Europa

    NASA Astrophysics Data System (ADS)

    Han, Lijie; Showman, A. P.

    2007-10-01

    Ridges are ubiquitous on Europa; parts of the satellite are covered solely by multiple generations of overprinted ridge pairs. Typically, ridges are 100-300 m in height, a few kilometers in width, and contain a central trough. Many ridge-formation scenarios have been suggested, including runaway frictional heating along fractures, which causes a temperature increase and leads to buoyant uplift along the fracture. Here we present 2D and 3D numerical simulations of ice-shell convection to test the role of shear heating and weakening by fractures on Europan ridge formation. We used the finite-element codes ConMan and CitCom to solve the equations governing thermal convection in Europa's ice shell in two- and three- dimensional Cartesian geometry. Our simulations show that a pre-existing fracture zone promotes upwelling and lithospheric thinning, leading to topographic uplift of 50 m; although promising, this is insufficient to explain the topography of Europan ridges. Shear heating also promotes lithospheric thinning and buoyant ascent, producing a linear feature with topography up to 120 m. Topography remains linear along strike even under the influence of heterogeneous 3D convection within the ice shell. Our simulated topography broadly resembles that of Europan ridges, including (in most simulations) the shallow marginal troughs on either side of the ridge, although the central trough is not reproduced. Despite this deficiency, our simulations support the idea that shear heating can produce Europa's ridges. Although the simulations presented here assumed a pure-ice composition, compositional effects could play an important role in ridge formation, and these effects will be considered in a future study.

  10. Large-scale changes of the temperature frontal zones and regional features in heat transfer patterns based on SST data

    NASA Astrophysics Data System (ADS)

    Kartushinsky, A.; Shishkin, A.

    The intensity of heat transfer by currents influences on the location of energetically active zones in the ocean In such zones the hydrological parameter gradients increase which reveals the structure of frontal zones SST data isn t enough to determine the location of such zones In our work we calculate according to AVHRR MCSST data the temperature gradients in the ocean that show the large-scale changes of the temperature frontal zones TFZ for the 1982 -- 1986 average monthly and 1990 -- 2001 average weekly periods To study how the temperature frontal zones are connected with the regional heat patterns we use the data concerned with the space-time variability of SST gradients for separate Pacific regions In our case the focus is placed on the investigation of the connection between the formation of the El Ni v n o-Southern Oscillation South-East Pacific and the variability of the heat transfer near the shores of North-West Pacific For the investigation of the main factors influencing on the heat redistribution in the ocean and of the reasons for the large-scale changes in the TFZ structure we use a two-dimensional horizontal numerical model of heat transfer The model takes into consideration the current speed turbulent diffusion and solar radiation Besides the results were obtained concerning heat transformation in several regions of North and South Atlantic which had been caused by the large-scale changes in the TFZ structure The research results and model experiments allow to identify the time scale of the temperature field

  11. Periodic Viscous Shear Heating Instability in Fine-Grained Shear Zones: Possible Mechanism for Intermediate Depth Earthquakes and Slow Earthquakes?

    NASA Astrophysics Data System (ADS)

    Kelemen, P. B.; Hirth, G.

    2004-12-01

    Localized ductile shear zones with widths of cm to m are observed in exposures of Earth's shallow mantle (e.g., Kelemen & Dick JGR 95; Vissers et al. Tectonophys 95) and dredged from oceanic fracture zones (e.g., Jaroslow et al. Tectonophys 96). These are mylonitic (grain size 10 to 100 microns) and record mineral cooling temperatures from 1100 to 600 C. Pseudotachylites in a mantle shear zone show that shear heating temperatures can exceed the mantle solidus (e.g., Obata & Karato Tectonophys 95). Simple shear, recrystallization, and grain boundary sliding all decrease the spacing between pyroxenes, so olivine grain growth at lower stress is inhibited; thus, once formed, these shear zones do not "heal" on geological time scales. Reasoning that grain-size sensitive creep will be localized within these shear zones, rather than host rocks (grain size 1 to 10 mm), and inspired by the work of Whitehead & Gans (GJRAS 74), we thought these might undergo repeated shear heating instabilities. In this view, as elastic stress increases, the shear zone weakens via shear heating; rapid deformation of the weak shear zone releases most stored elastic stress; lower stress and strain rate coupled with diffusion of heat into host rocks leads to cooling and strengthening, after which the cycle repeats. We constructed a simple numerical model incorporating olivine flow laws for dislocation creep, diffusion creep, grain boundary sliding, and low T plasticity. We assumed that viscous deformation remains localized in shear zones, surrounded by host rocks undergoing elastic deformation. We fixed the velocity along one side of an elastic half space, and calculated stress due to elastic strain. This stress drives viscous deformation in a shear zone of specified width. Shear heating and thermal diffusion control temperature evolution in the shear zone and host rocks. A maximum of 1400 C (where substantial melting of peridotite would occur) is imposed. Grain size evolves during dislocation

  12. Pyrometamorphism of Fault Zone Rocks Induced by Frictional Heating in High-velocity Friction Tests: Reliable Records of Seismic Slip?

    NASA Astrophysics Data System (ADS)

    Ree, J.; Ando, J.; Kim, J.; Han, R.; Shimamoto, T.

    2008-12-01

    Recognition of seismic slip zone is important for a better understanding of earthquake generation processes in fault zones and paleoseismology. However, there has been no reliable record of ancient seismic slip except pseudotachylyte. Recently, it has been suggested that decomposition (dehydration or decarbonation) products due to frictional heating can be used as a seismic slip record. The decomposition products, however, can be easily rehydrated or recarbonated with pervasive fluid migration in the fault zone after seismic slip, raising some question about their stability as a seismic slip record. Here, we review microstructural and mineralogical changes of the simulated fault zones induced by frictional heating (pyrometamorphism) from high-velocity friction tests (HVFT) on siltstone, sandstone and carbonates at seismic slip rates, and discuss on their stability after seismic slip. HVFT on siltstone generates pseuodotachylyte in the principal slip zone (0.30-0.75 mm thick) with 'damage' layer (0.1-0.2 mm thick) along its margins. Chlorite in the damage layer suffers an incipient dehydration with many voids (0.2-1.0 μm in diameter) in transmission electron microscopy (TEM), appearing as dark tiny spots both in plane-polarized light and back-scattered electron (BSE) photomicrographs. HVFT on brown sandstone induces a color change of wall rocks adjacent to the principal slip zone (brown to red) due to the dehydration of iron hydroxides with frictional heating. These dehydration products in siltstone and sandstone due to frictional heating may be unstable since they would be easily rehydrated with fluid infiltration after a seismic slip. HVFT on carbonates including Carrara marble and siderite-bearing gouges produces decarbonation products of nano-scale lime (CaO) and magnetite (Fe3O4), respectively. Lime is a very unstable phase whereas magnetite is a stable and thus may be used as an indicator of seismic slip. The simulated fault zones of Carrara marble contain

  13. How Hospitable Are Space Weather Affected Habitable Zones? The Role of Ion Escape

    NASA Astrophysics Data System (ADS)

    Airapetian, Vladimir S.; Glocer, Alex; Khazanov, George V.; Loyd, R. O. P.; France, Kevin; Sojka, Jan; Danchi, William C.; Liemohn, Michael W.

    2017-02-01

    Atmospheres of exoplanets in the habitable zones around active young G-K-M stars are subject to extreme X-ray and EUV (XUV) fluxes from their host stars that can initiate atmospheric erosion. Atmospheric loss affects exoplanetary habitability in terms of surface water inventory, atmospheric pressure, the efficiency of greenhouse warming, and the dosage of the UV surface irradiation. Thermal escape models suggest that exoplanetary atmospheres around active K-M stars should undergo massive hydrogen escape, while heavier species including oxygen will accumulate forming an oxidizing atmosphere. Here, we show that non-thermal oxygen ion escape could be as important as thermal, hydrodynamic H escape in removing the constituents of water from exoplanetary atmospheres under supersolar XUV irradiation. Our models suggest that the atmospheres of a significant fraction of Earth-like exoplanets around M dwarfs and active K stars exposed to high XUV fluxes will incur a significant atmospheric loss rate of oxygen and nitrogen, which will make them uninhabitable within a few tens to hundreds of Myr, given a low replenishment rate from volcanism or cometary bombardment. Our non-thermal escape models have important implications for the habitability of the Proxima Centauri’s terrestrial planet.

  14. Regional Climate Zone Modeling of a Commercial Absorption Heat Pump Hot Water Heater Part 1: Southern and South Central Climate Zones

    SciTech Connect

    Geoghegan, Patrick J; Shen, Bo; Keinath, Christopher M.; Garrabrant, Michael A.

    2016-01-01

    Commercial hot water heating accounts for approximately 0.78 Quads of primary energy use with 0.44 Quads of this amount from natural gas fired heaters. An ammonia-water based commercial absorption system, if fully deployed, could achieve a high level of savings, much higher than would be possible by conversion to the high efficiency nonheat-pump gas fired alternatives. In comparison with air source electric heat pumps, the absorption system is able to maintain higher coefficients of performance in colder climates. The ammonia-water system also has the advantage of zero Ozone Depletion Potential and low Global Warming Potential. A thermodynamic model of a single effect ammonia-water absorption system for commercial space and water heating was developed, and its performance was investigated for a range of ambient and return water temperatures. This allowed for the development of a performance map which was then used in a building energy modeling software. Modeling of two commercial water heating systems was performed; one using an absorption heat pump and another using a condensing gas storage system. The energy and financial savings were investigated for a range of locations and climate zones in the southern and south central United States. A follow up paper will analyze northern and north/central regions. Results showed that the system using an absorption heat pump offers significant savings.

  15. Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4

    SciTech Connect

    Sweet, M. L.; Francisco, A.; Roberts, S. G.

    2016-05-01

    The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas. Exhaust ducts should be insulated to avoid condensation on the exterior, however this imposes a risk of condensation occurring in the duct's interior near the HPWH due to large variation of temperatures between the compressor and the duct and the presence of bulk moisture around the condenser. The HPWH's air conditioning impact on HVAC equipment loads is minimal when the intake and exhaust air streams are connected to a sealed attic and not the living space. A HPWH is not suitable as a replacement dehumidifier in sealed attics as peak moisture loads were observed to only be reduced if the heat pump operated during the morning. It appears that the intake air temperature and humidity was the most dominant variable affecting HPWH performance. Different ducting strategies such as exhaust duct only, intake duct only, and exhaust and intake ducting did not have any effect on HPWH performance.

  16. Use of coastal zone color scanner imagery to identify nearshore ocean areas affected by land-based pollutants. Final report

    SciTech Connect

    LaPointe, T.F.; Basta, D.J.

    1981-01-01

    The purpose of the analysis was to use remotely sensed satellite imagery to determine the spatial boundaries of nearshore areas or zones likely to be affected by pollutants from land-based sources, so that data collected on the presence or absence of living marine resources could be combined with information on land-based pollutant discharges in a preliminary relative assessment of potential risk. Ocean zones of impact related to East Coast estuaries and embayments were approximated using reflectance patterns from data transmitted from the Coastal Zone Color Scanner (CZCS) instrument mounted on the NASA Nimbus-7 satellite. Data were transformed from numerical measures of radiance to photographic images suitable for identifying and mapping ocean impact zones through a simple enhancement technique.

  17. Characteristics of urban heat island distribution in Guangxi Beibu Gulf Economic Zone based on MOD11A2

    NASA Astrophysics Data System (ADS)

    Wang, Yong-feng; Jing, Juan-li

    2015-12-01

    The diurnal variation and inter-annual variation of urban heat island in Beibu Gulf Economic Zone were quantitatively analyzed, based on 2005-2014 MOD11A2 land surface temperature dataset, by the method of land surface temperature departure. Furthermore, the relationship between vegetation NDVI and urban heat island intensity were studied. Results showed: (1) Spatial distribution and extent of urban heat island in Beibu Gulf Economic Zone had a certain difference between daytime and nighttime in summer, the temperature departure decrease with distance from the city center increasing, and the decreasing trend of daytime was significant compared with nighttime. The temperature difference was about 4 to °C between the city and suburb in the daytime, and was about 2-6°C at night (2) The inter-annual variation intensity of urban heat island was not obvious in summer daytime during 2005-2014, while the difference of spatial distribution was significant. The urban heat island intensity increased in Nanning city during 2005-2011, and slowed in 2014. The heat island variation intensity was not obvious in Beihai city before 2011, but increased significantly in 2014. (3) The correlation coefficient between NDVI and land surface temperature in summer is -0.29, which showed high vegetation coverage plays an important role in reducing the urban heat island.

  18. Factors affecting gas migration and contaminant redistribution in heterogeneous porous media subject to electrical resistance heating.

    PubMed

    Munholland, Jonah L; Mumford, Kevin G; Kueper, Bernard H

    2016-01-01

    A series of intermediate-scale laboratory experiments were completed in a two-dimensional flow cell to investigate gas production and migration during the application of electrical resistance heating (ERH) for the removal of dense non-aqueous phase liquids (DNAPLs). Experiments consisted of heating water in homogeneous silica sand and heating 270 mL of trichloroethene (TCE) and chloroform (CF) DNAPL pools in heterogeneous silica sands, both under flowing groundwater conditions. Spatial and temporal distributions of temperature were measured using thermocouples and observations of gas production and migration were collected using front-face image capture throughout the experiments. Post-treatment soil samples were collected and analyzed to assess DNAPL removal. Results of experiments performed in homogeneous sand subject to different groundwater flow rates showed that high groundwater velocities can limit subsurface heating rates. In the DNAPL pool experiments, temperatures increased to achieve DNAPL-water co-boiling, creating estimated gas volumes of 131 and 114 L that originated from the TCE and CF pools, respectively. Produced gas migrated vertically, entered a coarse sand lens and subsequently migrated laterally beneath an overlying capillary barrier to outside the heated treatment zone where 31-56% of the original DNAPL condensed back into a DNAPL phase. These findings demonstrate that layered heterogeneity can potentially facilitate the transport of contaminants outside the treatment zone by mobilization and condensation of gas phases during ERH applications. This underscores the need for vapor phase recovery and/or control mechanisms below the water table during application of ERH in heterogeneous porous media during the co-boiling stage, which occurs prior to reaching the boiling point of water.

  19. Factors affecting gas migration and contaminant redistribution in heterogeneous porous media subject to electrical resistance heating

    NASA Astrophysics Data System (ADS)

    Munholland, Jonah L.; Mumford, Kevin G.; Kueper, Bernard H.

    2016-01-01

    A series of intermediate-scale laboratory experiments were completed in a two-dimensional flow cell to investigate gas production and migration during the application of electrical resistance heating (ERH) for the removal of dense non-aqueous phase liquids (DNAPLs). Experiments consisted of heating water in homogeneous silica sand and heating 270 mL of trichloroethene (TCE) and chloroform (CF) DNAPL pools in heterogeneous silica sands, both under flowing groundwater conditions. Spatial and temporal distributions of temperature were measured using thermocouples and observations of gas production and migration were collected using front-face image capture throughout the experiments. Post-treatment soil samples were collected and analyzed to assess DNAPL removal. Results of experiments performed in homogeneous sand subject to different groundwater flow rates showed that high groundwater velocities can limit subsurface heating rates. In the DNAPL pool experiments, temperatures increased to achieve DNAPL-water co-boiling, creating estimated gas volumes of 131 and 114 L that originated from the TCE and CF pools, respectively. Produced gas migrated vertically, entered a coarse sand lens and subsequently migrated laterally beneath an overlying capillary barrier to outside the heated treatment zone where 31-56% of the original DNAPL condensed back into a DNAPL phase. These findings demonstrate that layered heterogeneity can potentially facilitate the transport of contaminants outside the treatment zone by mobilization and condensation of gas phases during ERH applications. This underscores the need for vapor phase recovery and/or control mechanisms below the water table during application of ERH in heterogeneous porous media during the co-boiling stage, which occurs prior to reaching the boiling point of water.

  20. Factors Affecting Motivation and Job Satisfaction of Academic Staff of Universities in South-South Geopolitical Zone of Nigeria

    ERIC Educational Resources Information Center

    Osakwe, Regina N.

    2014-01-01

    This study determined the factors affecting motivation and job satisfaction of non-management academic staff of universities in South-South geopolitical zone of Nigeria. It employed an expost-facto research design. Three research questions and two hypotheses were raised for the study. A sample of four hundred and fifty non-management academic…

  1. Factors affecting the dynamics of the honeybee (Apis mellifera) hybrid zone of South Africa.

    PubMed

    Beekman, M; Allsopp, M H; Wossler, T C; Oldroyd, B P

    2008-01-01

    Hybrid zones are found wherever two populations distinguishable on the basis of heritable characters overlap spatially and temporally and hybridization occurs. If hybrids have lower fitness than the parental types a tension zone may emerge, in which there is a barrier to gene flow between the two parental populations. Here we discuss a hybrid zone between two honeybee subspecies, Apis mellifera capensis and A. m. scutellata and argue that this zone is an example of a tension zone. This tension zone is particularly interesting because A. m. capensis can be a lethal social parasite of A. m. scutellata. However, despite its parasitic potential, A. m. capensis appears to be unable to increase its natural range unassisted. We propose three interlinked mechanisms that could maintain the South African honeybee hybrid zone: (1) low fitness of intercrossed and genetically mixed colonies arising from inadequate regulation of worker reproduction; (2) higher reproductive success of A. m. scutellata via both high dispersal rates into the hybrid zone and increased competitiveness of males, countered by (3) the parasitic nature of A. m. capensis.

  2. On the onset of multi-wave patterns in laterally heated floating zones for slightly supercritical conditions

    NASA Astrophysics Data System (ADS)

    Lappa, Marcello

    2016-12-01

    This analysis follows and integrates the line of inquiry started in past author's works [M. Lappa, "Three-dimensional numerical simulation of Marangoni flow instabilities in floating zones laterally heated by an equatorial ring," Phys. Fluids 15(3), 776-789 (2003) and "Combined effect of volume and gravity on the three-dimensional flow instability in non-cylindrical floating zones heated by an equatorial ring," ibid. 16(2), 331-343 (2004)] about the typical instabilities of the Marangoni flow and associated hierarchy of bifurcations in laterally heated floating zones with various shapes and aspect ratios. The main motivation for re-examining this kind of problems, which have attracted so much attention over the last twenty years, is the recent discovery [M. Kudo et al., "Transition of thermocapillary convection in a full-zone liquid bridge," Trans. JSME (in Japanese) 80(812), TEP0095 (2014)] of a chaotic state in the region of the space of parameters where on the basis of existing theories and earlier results for the classical liquid-bridge problem with organic fluids, the flow should be relatively regular in time and with a simple structure in space. Axisymmetric computations are used to obtain the steady basic state, and then the Navier Stokes equations are solved in their complete, three-dimensional, time-dependent, and non-linear formulation to investigate the evolution of azimuthal disturbances. It is shown that the "apparent" doubling or quadrupling of the azimuthal wavenumber in the equatorial plane, previously reported for the case of floating zones of liquid metals, is replaced for high-Prandtl-number liquids by the complex interaction of disturbances with distinct spatial and temporal scales. These disturbances become critical at relatively comparable values of the Marangoni number. The unexpected multiplicity of waveforms and competition of spatial modes are explained according to the increased complexity of the considered system in terms of flow

  3. Localized heating of electrons in ionization zones: Going beyond the Penning-Thornton paradigm in magnetron sputtering

    SciTech Connect

    Anders, Andre

    2014-12-07

    The fundamental question of how energy is supplied to a magnetron discharge is commonly answered by the Penning-Thornton paradigm invoking secondary electrons. Huo et al. (Plasma Sources Sci. Technol. 22, 045005, (2013)) used a global discharge model to show that electron heating in the electric field of the magnetic presheath is dominant. In this contribution, this concept is applied locally taking into account the electric potential structure of ionization zones. Images of ionization zones can and should be interpreted as diagrams of the localization of electric potential and related electron energy, where certain collisions promote or dampen their formation.

  4. Protein Molecular Structures, Protein SubFractions, and Protein Availability Affected by Heat Processing: A Review

    SciTech Connect

    Yu,P.

    2007-01-01

    The utilization and availability of protein depended on the types of protein and their specific susceptibility to enzymatic hydrolysis (inhibitory activities) in the gastrointestine and was highly associated with protein molecular structures. Studying internal protein structure and protein subfraction profiles leaded to an understanding of the components that make up a whole protein. An understanding of the molecular structure of the whole protein was often vital to understanding its digestive behavior and nutritive value in animals. In this review, recently obtained information on protein molecular structural effects of heat processing was reviewed, in relation to protein characteristics affecting digestive behavior and nutrient utilization and availability. The emphasis of this review was on (1) using the newly advanced synchrotron technology (S-FTIR) as a novel approach to reveal protein molecular chemistry affected by heat processing within intact plant tissues; (2) revealing the effects of heat processing on the profile changes of protein subfractions associated with digestive behaviors and kinetics manipulated by heat processing; (3) prediction of the changes of protein availability and supply after heat processing, using the advanced DVE/OEB and NRC-2001 models, and (4) obtaining information on optimal processing conditions of protein as intestinal protein source to achieve target values for potential high net absorbable protein in the small intestine. The information described in this article may give better insight in the mechanisms involved and the intrinsic protein molecular structural changes occurring upon processing.

  5. Factors affecting carbon-14 activity of unsaturated zone CO2 and implications for groundwater dating

    NASA Astrophysics Data System (ADS)

    Wood, Cameron; Cook, Peter G.; Harrington, Glenn A.; Meredith, Karina; Kipfer, Rolf

    2014-11-01

    Unsaturated zone processes may influence the carbon-14 (14C) activity of infiltrating groundwater and thus introduce error in derived groundwater residence times. However unsaturated zone 14C activities are rarely measured and there is little understanding of how they may vary spatially in a groundwater basin. In this study we measured 14C activity in unsaturated zone gas at five sites with different watertable depths (8.2-31.5 m) in the arid Ti Tree Basin, central Australia. We observed a relatively uniform decrease in 14C activity of unsaturated zone gas with depth at most sites, with variation in unsaturated zone depths leading to variation in 14C activities directly above the watertable at each site (ranging from 54 to 106 percent Modern Carbon (pMC)). Through modelling we show that the profiles are influenced by CO2 production at different depths from sources with different isotopic ratios, including production of ‘modern' CO2 in the root zone and production of ‘old' CO2 above the watertable. Scenario modelling showed that these processes are independent of recharge when recharge is low (0-10 mm y-1) but that higher recharge rates (>100 mm y-1) result in more advective transport of atmospheric CO2 to the watertable. The variation in 14C above the watertable was more sensitive to watertable depth and shallow and deep CO2 production rates. These findings offer insight into how unsaturated zone 14C activities may vary spatially and provide guidance as to when 14C depletion in unsaturated zone CO2 may become important for groundwater dating, particularly in arid settings.

  6. Prolonged self-paced exercise in the heat – environmental factors affecting performance

    PubMed Central

    Junge, Nicklas; Jørgensen, Rasmus; Flouris, Andreas D.; Nybo, Lars

    2016-01-01

    ABSTRACT In this review we examine how self-paced performance is affected by environmental heat stress factors during cycling time trial performance as well as considering the effects of exercise mode and heat acclimatization. Mean power output during prolonged cycling time trials in the heat (≥30°C) was on average reduced by 15% in the 14 studies that fulfilled the inclusion criteria. Ambient temperature per se was a poor predictor of the integrated environmental heat stress and 2 of the prevailing heat stress indices (WBGT and UTCI) failed to predict the environmental influence on performance. The weighing of wind speed appears to be too low for predicting the effect for cycling in trained acclimatized subjects, where performance may be maintained in outdoor time trials at ambient temperatures as high as 36°C (36°C UTCI; 28°C WBGT). Power output during indoor trials may also be maintained with temperatures up to at least 27°C when humidity is modest and wind speed matches the movement speed generated during outdoor cycling, whereas marked reductions are observed when air movement is minimal. For running, representing an exercise mode with lower movement speed and higher heat production for a given metabolic rate, it appears that endurance is affected even at much lower ambient temperatures. On this basis we conclude that environmental heat stress impacts self-paced endurance performance. However, the effect is markedly modified by acclimatization status and exercise mode, as the wind generated by the exercise (movement speed) or the environment (natural or fan air movement) exerts a strong influence. PMID:28090557

  7. Prolonged self-paced exercise in the heat - environmental factors affecting performance.

    PubMed

    Junge, Nicklas; Jørgensen, Rasmus; Flouris, Andreas D; Nybo, Lars

    2016-01-01

    In this review we examine how self-paced performance is affected by environmental heat stress factors during cycling time trial performance as well as considering the effects of exercise mode and heat acclimatization. Mean power output during prolonged cycling time trials in the heat (≥30°C) was on average reduced by 15% in the 14 studies that fulfilled the inclusion criteria. Ambient temperature per se was a poor predictor of the integrated environmental heat stress and 2 of the prevailing heat stress indices (WBGT and UTCI) failed to predict the environmental influence on performance. The weighing of wind speed appears to be too low for predicting the effect for cycling in trained acclimatized subjects, where performance may be maintained in outdoor time trials at ambient temperatures as high as 36°C (36°C UTCI; 28°C WBGT). Power output during indoor trials may also be maintained with temperatures up to at least 27°C when humidity is modest and wind speed matches the movement speed generated during outdoor cycling, whereas marked reductions are observed when air movement is minimal. For running, representing an exercise mode with lower movement speed and higher heat production for a given metabolic rate, it appears that endurance is affected even at much lower ambient temperatures. On this basis we conclude that environmental heat stress impacts self-paced endurance performance. However, the effect is markedly modified by acclimatization status and exercise mode, as the wind generated by the exercise (movement speed) or the environment (natural or fan air movement) exerts a strong influence.

  8. Heat Transfer Affected by Transverse Magnetic Field using 3D Modeling of Arc Plasma

    NASA Astrophysics Data System (ADS)

    Maeda, Yoshifumi; Tanaka, Tatsuro; Yamamoto, Shinji; Iwao, Toru

    2016-10-01

    Gas shielded metal arc welding is used to join the various metal because this is the high quality joining technology. Thus, this welding is used for a welding of large buildings such as bridges and LNG tanks. However, the welding defect caused by the heat transfer decrement may occur with increasing the wind velocity. This is because that the convection loss increases because the arc deflects to leeward side with increasing the wind velocity. In order to prevent from the arc deflection, it is used that the transverse magnetic field is applied to the arc. However, the arc deflection occurs with increasing the transverse magnetic field excessively. The energy balance of the arc is changed with increasing the convection loss caused by the arc deflection, and the heat transfer to the anode decreases. Therefore, the analysis including the arc and anode is necessary to elucidate the heat transfer to the anode. In this paper, the heat transfer affected by the transverse magnetic field using 3D modeling of the arc plasma is elucidated. The heat transfer to the anode is calculated by using the EMTF(electromagnetic thermal fluid) simulation with increasing the transverse magnetic field. As a result, the heat transfer decreased with increasing the transverse magnetic field.

  9. Soil organic matter and salinity affect copper bioavailability in root zone and uptake by Vicia faba L. plants.

    PubMed

    Matijevic, Lana; Romic, Davor; Romic, Marija

    2014-10-01

    Processes that control the mobility, transformation and toxicity of metals in soil are of special importance in the root-developing zone. For this reason, there is a considerable interest in understanding trace elements (TEs) behavior in soil, emphasising the processes by which plants take them up. Increased root-zone salinity can affect plant TEs uptake and accumulation in plant tissue. Furthermore, copper (Cu) complexation by soil organic matter (SOM) is an effective mechanism of Cu retention in soils, controlling thus its bioavailability. Therefore, a greenhouse pot experiment was conducted to study the effects of soil Cu contamination in a saline environment on faba bean (Vicia faba L.) element uptake. Treatment with NaCl salinity was applied (control, 50 mM NaCl and 100 mM NaCl) on faba bean plants grown in a control and in a soil spiked with Cu (250 and 500 mg kg(-1)). Low and high SOM content trial variants were studied. Cu accumulation occurred in faba bean leaf, pod and seed. Cu contamination affected plant element concentrations in leaves (Na, Ca, Mg, Mn), pod (Zn, Mn) and seed (Mn, Mo, Zn). Root-zone salinity also affected faba bean element concentrations. Furthermore, Cu contamination-salinity and salinity-SOM interactions were significant for pod Cu concentration, suggesting that Cu phytoavailability could be affected by these interactions. Future research will be focused on the mechanisms of Cu translocation in plant and adaptation aspects of abiotic stress.

  10. Dense gas in the Galactic central molecular zone is warm and heated by turbulence

    NASA Astrophysics Data System (ADS)

    Ginsburg, Adam; Henkel, Christian; Ao, Yiping; Riquelme, Denise; Kauffmann, Jens; Pillai, Thushara; Mills, Elisabeth A. C.; Requena-Torres, Miguel A.; Immer, Katharina; Testi, Leonardo; Ott, Juergen; Bally, John; Battersby, Cara; Darling, Jeremy; Aalto, Susanne; Stanke, Thomas; Kendrew, Sarah; Kruijssen, J. M. Diederik; Longmore, Steven; Dale, James; Guesten, Rolf; Menten, Karl M.

    2016-02-01

    Context. The Galactic center is the closest region where we can study star formation under extreme physical conditions like those in high-redshift galaxies. Aims: We measure the temperature of the dense gas in the central molecular zone (CMZ) and examine what drives it. Methods: We mapped the inner 300 pc of the CMZ in the temperature-sensitive J = 3-2 para-formaldehyde (p - H2CO) transitions. We used the 32,1-22,0/ 30,3-20,2 line ratio to determine the gas temperature in n ~ 104-105 cm-3 gas. We have produced temperature maps and cubes with 30'' and 1 km s-1 resolution and published all data in FITS form. Results: Dense gas temperatures in the Galactic center range from ~60 K to >100 K in selected regions. The highest gas temperatures TG> 100 K are observed around the Sgr B2 cores, in the extended Sgr B2 cloud, the 20 km s-1 and 50 km s-1 clouds, and in "The Brick" (G0.253+0.016). We infer an upper limit on the cosmic ray ionization rate ζCR< 10-14s-1. Conclusions: The dense molecular gas temperature of the region around our Galactic center is similar to values found in the central regions of other galaxies, in particular starburst systems. The gas temperature is uniformly higher than the dust temperature, confirming that dust is a coolant in the dense gas. Turbulent heating can readily explain the observed temperatures given the observed line widths. Cosmic rays cannot explain the observed variation in gas temperatures, so CMZ dense gas temperatures are not dominated by cosmic ray heating. The gas temperatures previously observed to be high in the inner ~75 pc are confirmed to be high in the entire CMZ. The data can be accessed from doi:10.7910/DVN/27601 and are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/586/A50

  11. Variable power distribution for zoned regeneration of an electrically heated particulate filter

    DOEpatents

    Bhatia, Garima [Bangalore, IN; Gonze, Eugene V [Pinckney, MI

    2012-04-03

    A system includes a particulate matter (PM) filter with multiple zones, an electric heater and a control module. The electrical heater includes heater segments, which each correspond with a respective one of the zones. The electrical heater is arranged upstream from and is proximate with the PM filter. The control module selectively applies a first energy level to a first one of the zones via a first one of the heater segments to initiate regeneration in the first zone. The control module also selectively applies a second energy level that is less than the first energy level to a second one of the zones via a second one of the heater segments to initiate regeneration in the second zone.

  12. Heat stress but not inbreeding affects offensive sperm competitiveness in Callosobruchus maculatus

    PubMed Central

    Lieshout, Emile; Tomkins, Joseph L; Simmons, Leigh W

    2013-01-01

    Environmental and genetic stress have well-known detrimental effects on ejaculate quality, but their concomitant effect on male fitness remains poorly understood. We used competitive fertilization assays to expose the effects of stress on offensive sperm competitive ability in the beetle Callosobruchus maculatus, a species where ejaculates make up more than 5% of male body mass. To examine the effects of environmental and genetic stress, males derived from outcrosses or sib matings were heat shocked at 50°C for 50 min during the pupal stage, while their siblings were maintained at a standard rearing temperature of 28°C. Heat-shocked males achieved only half the offensive paternity success of their siblings. While this population exhibited inbreeding depression in body size, sperm competitiveness was unaffected by inbreeding, nor did the effect of heat shock stress on sperm competitiveness depend on inbreeding status. In contrast, pupal emergence success was increased by 34% among heat-stressed individuals, regardless of their inbreeding status. Heat-shocked males' ejaculate size was 19% reduced, but they exhibited 25% increased mating duration in single mating trials. Our results highlight both the importance of stress in postcopulatory sexual selection, and the variability among stressors in affecting male fitness. PMID:24101978

  13. Studies on wake-affected heat transfer around the circular leading edge of blunt body

    SciTech Connect

    Funazaki, K.

    1996-07-01

    Detailed measurements are performed about time-averaged heat transfer distributions around the leading edge of a blunt body, which is affected by incoming periodic wakes from the upstream moving bars. The blunt body is a test model of a front portion of a turbine blade in gas turbines and consists of a semicircular cylindrical leading edge and a flat plate afterbody. A wide range of the steady and unsteady flow conditions are adopted as for the Reynolds number based on the diameter of the leading edge and the bar-passing Strouhal number. The measured heat transfer distributions indicate that the wakes passing over the leading edge cause a significant increase in heat transfer before the separation and the higher Strouhal number results in higher heat transfer. From this experiment, a correlation for the heat transfer enhancement around the leading edge due to the periodic wakes is deduced as a function of the Stanton number and it is reviewed by comparison with the other experimental works.

  14. Heat stress but not inbreeding affects offensive sperm competitiveness in Callosobruchus maculatus.

    PubMed

    Lieshout, Emile; Tomkins, Joseph L; Simmons, Leigh W

    2013-09-01

    Environmental and genetic stress have well-known detrimental effects on ejaculate quality, but their concomitant effect on male fitness remains poorly understood. We used competitive fertilization assays to expose the effects of stress on offensive sperm competitive ability in the beetle Callosobruchus maculatus, a species where ejaculates make up more than 5% of male body mass. To examine the effects of environmental and genetic stress, males derived from outcrosses or sib matings were heat shocked at 50°C for 50 min during the pupal stage, while their siblings were maintained at a standard rearing temperature of 28°C. Heat-shocked males achieved only half the offensive paternity success of their siblings. While this population exhibited inbreeding depression in body size, sperm competitiveness was unaffected by inbreeding, nor did the effect of heat shock stress on sperm competitiveness depend on inbreeding status. In contrast, pupal emergence success was increased by 34% among heat-stressed individuals, regardless of their inbreeding status. Heat-shocked males' ejaculate size was 19% reduced, but they exhibited 25% increased mating duration in single mating trials. Our results highlight both the importance of stress in postcopulatory sexual selection, and the variability among stressors in affecting male fitness.

  15. Superconducting accelerator cavity with a heat affected zone having a higher RRR

    DOEpatents

    Brawley, John; Phillips, H. Lawrence

    2000-01-01

    An improved method for welding accelerator cavities without the need for time consuming and expensive faying surface treatments comprising electron beam welding such cavities in a vacuum welding chamber within a vacuum envelope and using the following welding parameters: a beam voltage of between about 45 KV and 55 KV; a beam current between about 38 ma and 47 ma; a weld speed of about 15 cm/min; and a sharp focus and a rhombic raster of between about 9 KHz and 10 Khz. A welded cavity made according to the method of the present invention is also described.

  16. Identifying Local Scale Climate Zones of Urban Heat Island from HJ-1B Satellite Data Using Self-Organizing Maps

    NASA Astrophysics Data System (ADS)

    Wei, C. Z.; Blaschke, T.

    2016-10-01

    With the increasing acceleration of urbanization, the degeneration of the environment and the Urban Heat Island (UHI) has attracted more and more attention. Quantitative delineation of UHI has become crucial for a better understanding of the interregional interaction between urbanization processes and the urban environment system. First of all, our study used medium resolution Chinese satellite data-HJ-1B as the Earth Observation data source to derive parameters, including the percentage of Impervious Surface Areas, Land Surface Temperature, Land Surface Albedo, Normalized Differential Vegetation Index, and object edge detector indicators (Mean of Inner Border, Mean of Outer border) in the city of Guangzhou, China. Secondly, in order to establish a model to delineate the local climate zones of UHI, we used the Principal Component Analysis to explore the correlations between all these parameters, and estimate their contributions to the principal components of UHI zones. Finally, depending on the results of the PCA, we chose the most suitable parameters to classify the urban climate zones based on a Self-Organization Map (SOM). The results show that all six parameters are closely correlated with each other and have a high percentage of cumulative (95%) in the first two principal components. Therefore, the SOM algorithm automatically categorized the city of Guangzhou into five classes of UHI zones using these six spectral, structural and climate parameters as inputs. UHI zones have distinguishable physical characteristics, and could potentially help to provide the basis and decision support for further sustainable urban planning.

  17. HEAT AND MASS TRANSFER IN THE VADOSE ZONE WITH PLANT ROOTS. (R825414)

    EPA Science Inventory

    Abstract

    The vadose zone is the intermediate medium between the atmosphere and groundwater. The modeling of the processes taking place in the vadose zone needs different approaches to those needed for groundwater transport problems because of the marked changes in envi...

  18. Surface heat flow and CO2 emissions within the Ohaaki hydrothermal field, Taupo Volcanic Zone, New Zealand

    USGS Publications Warehouse

    Rissmann, C.; Christenson, B.; Werner, C.; Leybourne, M.; Cole, J.; Gravley, D.

    2012-01-01

    Carbon dioxide emissions and heat flow have been determined from the Ohaaki hydrothermal field, Taupo Volcanic Zone (TVZ), New Zealand following 20a of production (116MW e). Soil CO2 degassing was quantified with 2663 CO2 flux measurements using the accumulation chamber method, and 2563 soil temperatures were measured and converted to equivalent heat flow (Wm -2) using published soil temperature heat flow functions. Both CO2 flux and heat flow were analysed statistically and then modelled using 500 sequential Gaussian simulations. Forty subsoil CO 2 gas samples were also analysed for stable C isotopes. Following 20a of production, current CO2 emissions equated to 111??6.7T/d. Observed heat flow was 70??6.4MW, compared with a pre-production value of 122MW. This 52MW reduction in surface heat flow is due to production-induced drying up of all alkali-Cl outflows (61.5MW) and steam-heated pools (8.6MW) within the Ohaaki West thermal area (OHW). The drying up of all alkali-Cl outflows at Ohaaki means that the soil zone is now the major natural pathway of heat release from the high-temperature reservoir. On the other hand, a net gain in thermal ground heat flow of 18MW (from 25MW to 43.3??5MW) at OHW is associated with permeability increases resulting from surface unit fracturing by production-induced ground subsidence. The Ohaaki East (OHE) thermal area showed no change in distribution of shallow and deep soil temperature contours despite 20a of production, with an observed heat flow of 26.7??3MW and a CO 2 emission rate of 39??3T/d. The negligible change in the thermal status of the OHE thermal area is attributed to the low permeability of the reservoir beneath this area, which has limited production (mass extraction) and sheltered the area from the pressure decline within the main reservoir. Chemistry suggests that although alkali-Cl outflows once contributed significantly to the natural surface heat flow (~50%) they contributed little (<1%) to pre-production CO 2

  19. Urban Heat Island Variation across a Dramatic Coastal to Desert Climate Zone: An Application to Los Angeles, CA Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Tayyebi, A.; Jenerette, D.

    2015-12-01

    Urbanization is occurring at an unprecedented rate across the globe. The resulting urban heat island (UHI), which is a well-known phenomenon in urban areas due to the increasing number and density of buildings, leads to higher temperature in urban areas than surrounding sub-urban or rural areas. Understanding the effects of landscape pattern on UHI is crucial for improving the sustainability of cities and reducing heat vulnerability. Although a variety of studies have quantified UHI, there are a lack of studies to 1) understand UHI variation at the micro-scale (e.g., neighborhood effect) for large urban areas and 2) identify variation in the sensitivity of the UHI to environmental drivers across a megacity with a pronounced climate zone (i.e. coastal to desert climates) using advanced analytical tools. In this study, we identified the interacting relationship among various environmental and socio-economic factors to better identify UHI over the Los Angeles, CA metropolitan area. We used structural equation modeling (SEM) to quantify the interacting relationships among land surface temperature (LST), land cover (NDVI), distance to ocean, elevation, and socio-economic status (neighborhood income). LST-NDVI slopes were negative across the climate zones and became progressively stronger with increasing distance from the coast. Results also showed that slopes between NDVI and neighborhood income were positive throughout the climate zone with a maximum in the relationship occurring near 25km from the coast. Because of these income-NDVI and NDVI-LST relationships we also found that slopes between LST and neighborhood income were negative throughout the climate zones and peaked at about 30km from the coast. These findings suggest assessments of urban heat vulnerability need to consider not only variation in the indicators but also variation in how the indicators influence vulnerability.

  20. Visualization of microcrack anisotropy in granite affected by afault zone, using confocal laser scanning microscope

    SciTech Connect

    Onishi, Celia T.; Shimizu, Ichiko

    2004-01-02

    Brittle deformation in granite can generate a fracture system with different patterns. Detailed fracture analyses at both macroscopic and microscopic scales, together with physical property data from a drill-core, are used to classify the effects of reverse fault deformation in four domains: (1) undeformed granite, (2) fractured granite with cataclastic seams, (3) fractured granite from the damage zone, and (4) foliated cataclasite from the core of the fault. Intact samples from two orthogonal directions, horizontal (H) and vertical (V), from the four domains indicate a developing fracture anisotropy toward the fault, which is highly developed in the damage zone. As a specific illustration of this phenomenon, resin impregnation, using a confocal laser scanning microscope (CLSM) technique is applied to visualize the fracture anisotropy developed in the Toki Granite, Japan. As a result, microcrack networks have been observed to develop in H sections and elongate open cracks in V sections, suggesting that flow pathways can be determined by deformation.

  1. Radiant heat affects thermoregulation and energy expenditure during rewarming from torpor.

    PubMed

    Geiser, F; Drury, R L

    2003-02-01

    The high expenditure of energy required for endogenous rewarming is one of the widely perceived disadvantages of torpor. However, recent evidence demonstrates that passive rewarming either by the increase of ambient temperature or by basking in the sun appears to be common in heterothermic birds and mammals. As it is presently unknown how radiant heat affects energy expenditure during rewarming from torpor and little is known about how it affects normothermic thermoregulation, we quantified the effects of radiant heat on body temperature and metabolic rate of the small (body mass 25 g) marsupial Sminthopsis macroura in the laboratory. Normothermic resting individuals exposed to radiant heat were able to maintain metabolic rates near basal levels (at 0.91 ml O(2) g(-1) h(-1)) and a constant body temperature down to an ambient temperature of 12 degrees C. In contrast, metabolic rates of individuals without access to radiant heat were 4.5-times higher at an ambient temperature of 12 degrees C and body temperature fell with ambient temperature. During radiant heat-assisted passive rewarming from torpor, animals did not employ shivering but appeared to maximise uptake of radiant heat. Their metabolic rate increased only 3.2-times with a 15- degrees C rise of body temperature (Q(10)=2.2), as predicted by Q(10) effects. In contrast, during active rewarming shivering was intensive and metabolic rates showed an 11.6-times increase. Although body temperature showed a similar absolute change between the beginning and the end of the rewarming process, the overall energetic cost during active rewarming was 6.3-times greater than that during passive, radiant heat-assisted rewarming. Our study demonstrates that energetic models assuming active rewarming from torpor at low ambient temperatures can substantially over-estimate energetic costs. The low energy expenditure during passive arousal provides an alternative explanation as to why daily torpor is common in sunny regions and

  2. Heat Stress Affects Facultative Symbiont-Mediated Protection from a Parasitoid Wasp

    PubMed Central

    Heyworth, Eleanor R.

    2016-01-01

    Many insects carry facultative bacterial symbionts, which provide benefits including resistance to natural enemies and abiotic stresses. Little is known about how these beneficial phenotypes are affected when biotic or abiotic threats occur simultaneously. The pea aphid (Acyrthosiphon pisum) can host several well-characterized symbiont species. The symbiont known as X-type can protect against both parasitoid wasps and heat stress. Here, we used three pea aphid genotypes that were naturally infected with X-type and the symbiont Spiroplasma sp. We compared aphids coinfected with these two symbionts with those cured from X-type and infected with only Spiroplasma to investigate the ability of X-type to confer benefits to the host when two threats are experienced simultaneously. Our aim is to explore how robust symbiont protection may be outside a benign laboratory environment. Aphids were subjected to heat shock either before or after attack by parasitoid wasps. Under a benign temperature regime, the aphids carrying X-type tended to be better protected from the parasitoid than those cured. When the aphids experienced a heat shock before being parasitized aphids carrying X-type were more susceptible than those cured. Regardless of infection with the symbiont, the aphids benefitted from being heat shocked after parasitization. The results demonstrate how resistance to parasitoid wasps can be strongly environment-dependent and that a beneficial phenotype conferred by a symbiont under controlled conditions in the laboratory does not necessarily equate to a consistently useful effect in natural populations. PMID:27875577

  3. Exertional heat illness: a review of the syndrome affecting racing Thoroughbreds in hot and humid climates.

    PubMed

    Brownlow, M A; Dart, A J; Jeffcott, L B

    2016-07-01

    Metabolic heat produced by Thoroughbred racehorses during racing can rapidly elevate core body temperature (1°C/min). When environmental conditions are hot and humid, the normal physiological cooling mechanisms become ineffective. The heat accumulated may exceed a critical thermal maximum (estimated to be 42°C), which may trigger a complex pathophysiological cascade with potentially lethal consequences. This syndrome has been labelled exertional heat illness (EHI). EHI is described in humans, but has not been well documented in Thoroughbred racehorses. The clinical signs described in racehorses would suggest that the pathophysiological events affecting the central nervous (CNS) and gastrointestinal systems are similar to those described in humans. Clinical signs are progressive and include signs of endotoxaemia and increasing levels of CNS dysfunction. Initially, horses that may be mildly irritable (agitated, randomly kicking out) may progress to unmanageable (disorientation, severe ataxia, falling) and ultimately convulsions, coma and death. Currently, the approach to treatment is largely empirical and involves rapid and effective cooling, administration of drugs to provide sedation, administration of non-steroidal anti-inflammatory drugs to ameliorate the effects of endotoxaemia and glucocorticoids to stabilise cell membranes and reduce the effects of inflammation on the CNS. This review provides an overview of the current knowledge about EHI in Thoroughbred racehorses, suggests a likely pathophysiology of the syndrome in horses based on the current literature on heat illness in humans and horses, and outlines current treatment strategies being used to treat racehorses with clinical signs of EHI.

  4. Seismic heating signatures in the Japan Trench subduction plate-boundary fault zone: evidence from a preliminary rock magnetic `geothermometer'

    NASA Astrophysics Data System (ADS)

    Yang, Tao; Dekkers, Mark J.; Zhang, Bo

    2016-04-01

    Frictional heating during earthquake rupture reveals important information on earthquake mechanisms and energy dissipation. The amount of annealing varies widely and is, as yet, poorly constrained. Here we use magnetic susceptibility versus temperature measurements during cycling to increasingly elevated temperatures to constrain the maximum temperature a slip zone has experienced. The case study comprises sheared clay cored from the Japan Trench subduction plate-boundary fault zone (décollement), which accommodated the large slip of the 2011 Mw 9.0 Tohoku-oki earthquake. The décollement was cored during the Integrated Ocean Drilling Program (IODP) Expedition 343, the Japan Trench Fast Drilling Project (JFAST). Heating signatures with estimated maximum temperatures ranging from ˜300 to over 500 °C are determined close to the multiple slip surfaces within the décollement. Since it is impossible to tie a specific slip surface to a certain earthquake, thermal evidence for the cumulative effect of several earthquakes is unveiled. This as yet preliminary rock magnetic `geothermometer' would be a useful tool to detect seismic heating along faults that experienced medium temperature rise, a range which is difficult to assess with other approaches.

  5. Denaturation and Oxidative Stability of Hemp Seed (Cannabis sativa L.) Protein Isolate as Affected by Heat Treatment.

    PubMed

    Raikos, Vassilios; Duthie, Garry; Ranawana, Viren

    2015-09-01

    The present study investigated the impact of heat treatments on the denaturation and oxidative stability of hemp seed protein during simulated gastrointestinal digestion (GID). Heat-denatured hemp protein isolate (HPI) solutions were prepared by heating HPI (2 mg/ml, pH 6.8) to 40, 60, 80 and 100 °C for 10 min. Heat-induced denaturation of the protein isolates was monitored by polyacrylamide gel electrophoresis. Heating HPI at temperatures above 80 °C significantly reduced solubility and led to the formation of large protein aggregates. The isolates were then subjected to in vitro GID and the oxidative stability of the generated peptides was investigated. Heating did not significantly affect the formation of oxidation products during GID. The results suggest that heat treatments should ideally remain below 80 °C if heat stability and solubility of HPI are to be preserved.

  6. Heat-induced aggregation of thylakoid membranes affect their interfacial properties.

    PubMed

    Östbring, Karolina; Rayner, Marilyn; Albertsson, Per-Åke; Erlanson-Albertsson, Charlotte

    2015-04-01

    Many of our most popular lipid containing foods are in emulsion form. These foods are often highly palatable with high caloric density, that subsequently increases the risk of overconsumption and possibly lead to obesity. Regulating the lipid bioavailability of high-fat foods is one approach to prevent overconsumption. Thylakoids, the chloroplast membrane, creates a barrier around lipid droplets, which prolong lipolysis and increase satiety as demonstrated both in animal and human studies. However, a reduced lipase inhibiting capacity has been reported after heat treatment but the mechanism has not yet been fully established. The aim of this study was to investigate thylakoids' emulsifying properties post heat-treatment and possible links to alterations in lipase inhibiting capacity and chlorophyll degradation. Heat-treatment of thylakoids at either 60 °C, 75 °C or 90 °C for time interval ranging from 15 s to 4 min reduced ability to stabilise emulsions, having increased lipid droplets sizes, reduced emulsification capacity, and elevated surface load as consequence. Emulsifying properties were also found to display a linear relationship to both chlorophyll and lipase inhibiting capacity. The correlations support the hypothesis that heat-treatment induce chlorophyll degradation which promote aggregation within proteins inside the thylakoid membrane known to play a decisive role in interfacial processes. Therefore, heat-treatment of thylakoids affects both chlorophyll content, lipase inhibiting capacity and ability to stabilise the oil-water interface. Since the thylakoid's appetite reducing properties are a surface-related phenomenon, the results are useful to optimize the effect of thylakoids as an appetite reducing agent.

  7. Heat transfer and fluid flow in floating-zone crystal growth with a mostly covered melt surface

    NASA Technical Reports Server (NTRS)

    Lan, C. W.; Kou, Sindo

    1992-01-01

    Computer simulation was conducted to study a modified floating-zone crystal growth process, in which the melt surface is mostly covered with a heated ring. The growth of 6-mm diameter single crystals of NaNO3 was considered, and the effects of the following parameters were studied: (1) temperature of the ring, (2) growth rate, (3) surface tension-temperature coefficient of the melt, (4) thermal expansion coefficient of the melt, and (5) gravity. It was demonstrated that thermocapillary convection in the melt zone is reduced significantly in this modified process. The model was checked against the measured lengths of the meniscus near the growth front and axial temperature distribution in a growing crystal, and the agreement was good.

  8. Exploration of the enhanced geothermal system (EGS) potential of crystalline rocks for district heating (Elbe Zone, Saxony, Germany)

    NASA Astrophysics Data System (ADS)

    Förster, Andrea; Förster, Hans-Jürgen; Krentz, Ottomar

    2016-12-01

    This paper addresses aspects of a baseline geothermal exploration of the thermally quiescent Elbe Zone (hosting the cities of Meissen and Dresden) for a potential deployment of geothermal heat in municipal heating systems. Low-permeable to impermeable igneous and metamorphic rocks constitute the major rock types at depth, implying that an enhanced geothermal system needs to be developed by creating artificial flow paths for fluids to enhance the heat extraction from the subsurface. The study includes the development of geological models for two areas on the basis of which temperature models are generated at upper crustal scale. The models are parameterized with laboratory-measured rock thermal properties (thermal conductivity k, radiogenic heat production H). The uncertainties of modelled temperature caused by observed variations of k and H and inferred mantle heat flow are assessed. The study delineates highest temperatures within the intermediate (monzonite/syenite unit) and mafic rocks (diorite/monzodiorite unit) forming the deeper portions of the Meissen Massif and, specifically for the Dresden area, also within the low-metamorphic rocks (slates/phyllites/quartzites) of the Elbtalschiefergebirge. Boreholes 3-4 km deep need to be drilled to reach the envisioned economically favourable temperatures of 120 °C. The metamorphic and mafic rocks exhibit low concentrations of U and Th, thus being advantageous for a geothermal use. For the monzonite/syenite unit of high heat production ( 6 µW m-3) in the Meissen Massif, the mobilization of Th and U into the geothermal working fluid is assumed to be minor, although their various radioactive decay products will be omnipresent during geothermal use.

  9. Norwegian fisheries in the Svalbard zone since 1980. Regulations, profitability and warming waters affect landings

    NASA Astrophysics Data System (ADS)

    Misund, Ole Arve; Heggland, Kristin; Skogseth, Ragnheid; Falck, Eva; Gjøsæter, Harald; Sundet, Jan; Watne, Jens; Lønne, Ole Jørgen

    2016-09-01

    The Svalbard archipelago in the High Arctic is influenced by cold Arctic water masses from the north-east and the warm West Spitsbergen Current flowing northwards along its western coast. The eastern waters and the fjords are normally frozen during the winter months, while the coastal waters west of the archipelago remain open. Norwegian fishers have been harvesting from Svalbard waters for decades and detailed records of catches exists from 1980 onwards. We analyze the catch records from the Svalbard zone (approximately ICES area IIb). The large fishery for capelin in summer yielding annual catches up to 737 000 tons was closed by a Norwegian fishery regulation in the mid nineteen nineties. Demersal fisheries have been continuous, and the results clearly indicate a northward trend in landings of Northeast Arctic cod, haddock, ling and Atlantic halibut. Fisheries of Northern shrimp have been more variable and shown no clear geographic trends. A "gold rush" fishery for scallops north of Svalbard lasted for about 10 years (1986-1995) only, and ended due to low profitably. These results are discussed in relation to the possibility of further northward extension of fisheries subjected to climate change.

  10. Factors Affecting the Latitudinal Location of the Intertropical Convergence Zone in a GCM

    NASA Technical Reports Server (NTRS)

    Chao, Winston C.; Chen, Baode

    2002-01-01

    The dominant role of the latitudinal peak of the sea surface temperature (SST) in determining the latitudinal location of the intertropical convergence zone (ITCZ) is well-known. However, the roles of the other factors are less well-known and are the topic of this study. These other factors include the inertial stability, the interaction between convection and surface fluxes and the interaction between convection and radiation. Since these interactions involve convection, in a model they involve the cumulus parameterization scheme. These factors are studied with a general circulation model with uniform SST and solar angle. Under the aforementioned model settings, the latitudinal location of the ITCZ is the latitude where the balance of two types of attraction on the ITCZ, both due to earth's rotation, exists. Directly related to the Coriolis parameter, the first type pulls the ITCZ toward the equator and is not sensitive to model design changes. Related to the convective circulation, the second type pulls the ITCZ poleward and is sensitive to model design changes. Due to the shape and the magnitude of the attractors, the balance of the two types of attractions is reached either at the equator or more than 10 degrees away from the equator. The former case results in a single ITCZ over the equator and the latter case a double ITCZ straddling the equator.

  11. Estimating the effect of shallow groundwater on diurnal heat transport in a vadose zone

    NASA Astrophysics Data System (ADS)

    Jiang, Jianmei; Zhao, Lin; Zhai, Zhe

    2016-09-01

    The influence of shallow groundwater on the diurnal heat transport of the soil profile was analyzed using a soil sensor automatic monitoring system that continuously measures temperature and water content of soil profiles to simulate heat transport based on the Philip and de Vries (PDV) model. Three experiments were conducted to measure soil properties at depths of 5 cm, 10 cm, 20 cm, and 30 cm when groundwater tables reached 10 cm, 30 cm, and 60 cm (Experiments I, II, and III). Results show that both the soil temperature near shallow groundwater and the soil water content were effectively simulated by the PDV model. The root mean square errors of the temperature at depths of 5 cm, 10 cm, and 20 cm were 1.018°C, 0.909°C, and 0.255°C, respectively. The total heat flux generated the convergent and divergent planes in space-time fields with valley values of-161.5W•m-2 at 7:30 and-234.6W•m-2 at 11:10 in Experiments II and III, respectively. The diurnal heat transport of the saturated soil occurred in five stages, while that of saturated-unsaturated and unsaturated soil profiles occurred in four stages because high moisture content led to high thermal conductivity, which hastened the heat transport.

  12. The Influence of Static and Rotating Magnetic Fields on Heat and Mass Transfer in Silicon Floating Zones

    NASA Technical Reports Server (NTRS)

    Croll, A.; Dold, P.; Kaiser, Th.; Szofran, F. R.; Benz, K. W.

    1999-01-01

    Heat and mass transfer in float-zone processing are strongly influenced by convective flows in the zone. They are caused by buoyancy convection, thermocapillary (Marangoni) convection, or artificial sources such as rotation and radio-frequency heating. Flows in conducting melts can be controlled by the use of magnetic fields, either by damping fluid motion with static fields or by generating a defined flow with rotating fields. The possibilities of using static and rotating magnetic fields in silicon floating-zone growth have been investigated by experiments in axial static fields up to 5 T and in transverse rotating magnetic fields up to 7.5 mT. Static fields of a few 100 mT already suppress most striations but are detrimental to the radial segregation by introducing a coring effect. A complete suppression of dopant striations caused by time-dependent thermocapillary convection and a reduction of the coring to insignificant values, combined with a shift of the axial segregation profile toward a more diffusion-limited case, is possible with static fields greater than or equal to 1 T. However, under certain conditions the use of high axial magnetic fields can lead to the appearance of a new type of pronounced dopant striations, caused by thermoelectromagnetic convection. The use of a transverse rotating magnetic field influences the microscopic segregation at quite low inductions, of the order of a few millitesla. The field shifts time- dependent flows and the resulting striation patterns from a broad range of low frequencies at high amplitudes to a few high frequencies at low amplitudes.

  13. Ageing Adversely Affects the Migration and Function of Marginal Zone B Cells.

    PubMed

    Turner, Vivian M; Mabbott, Neil A

    2017-04-02

    Marginal zone (MZ) B cells are positioned within the spleen to capture blood-borne Ag and immune complexes and deliver them to follicular dendritic cells in the B cell follicles. We show that within the spleens of aged mice antigen (Ag) capture by MZ B cells, and their ability to shuttle between the follicle and MZ were impaired. The ability of aged MZ B cells to migrate towards the MZ chemoattractant sphingosine 1-phosphate was increased, suggesting that aged MZ B cells had a greater propensity to be retained within the MZ. An extrinsic impairment in aged B cell migration towards the MZ was demonstrated using bone marrow chimeras. The follicular shuttling of MZ B cells derived from either young or aged bone marrow was similarly reduced in aged recipient spleens, showing that ageing effects on splenic stromal cells were responsible for the impaired follicular shuttling of MZ B cells. MZ B cells rapidly mount T cell-independent (TI) antibody-responses to microbial polysaccharide Ag. In aged mice the ability to produce immunoglobulins in response to the TI-type 1 Ag, TNP-LPS, was impaired. These ageing related changes to the MZ and MZ B cells have implications for the clearance of blood-borne pathogens. Indeed elderly people have increased susceptibility to Streptococcus pneumoniae, a TI Ag, and decreased responses to vaccination. A thorough analysis of the mechanisms that underpin the ageing-related decline in the status of the MZ and MZ B cells will help the design of novel treatments to improve immunity in the elderly. This article is protected by copyright. All rights reserved.

  14. Adaptation to heat and water shortage in large, arid-zone mammals.

    PubMed

    Fuller, Andrea; Hetem, Robyn S; Maloney, Shane K; Mitchell, Duncan

    2014-05-01

    Although laboratory studies of large mammals have revealed valuable information on thermoregulation, such studies cannot predict accurately how animals respond in their natural habitats. Through insights obtained on thermoregulatory behavior, body temperature variability, and selective brain cooling in free-living mammals, we show here how we can better understand the physiological capacity of large mammals to cope with hotter and drier arid-zone habitats likely with climate change.

  15. Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4

    SciTech Connect

    M. L. Sweet; Francisco, A.; Roberts, S. G.

    2016-05-01

    The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas.

  16. Ground-water heat pumps: an examination of hydrogeologic, environmental, legal, and economic factors affecting their use

    SciTech Connect

    Armitage, D M; Bacon, D J; Massey-Norton, J T; Miller, J D

    1980-11-12

    Groundwater is attractive as a potential low-temperature energy source in residential space-conditioning applications. When used in conjuncton with a heat pump, ground water can serve as both a heat source (for heating) and a heat sink (for cooling). Major hydrogeologic aspects that affect system use include groundwater temperature and availability at shallow depths as these factors influence operational efficiency. Ground-water quality is considered as it affects the performance and life-expectancy of the water-side heat exchanger. Environmental impacts related to groundwater heat pump system use are most influenced by water use and disposal methods. In general, recharge to the subsurface (usually via injection wells) is recommended. Legal restrictions on system use are often stricter at the municipal and county levels than at state and Federal levels. Although Federal regulations currently exist, the agencies are not equipped to regulate individual, domestic installations. Computer smulations indicate that under a variety of climatologic conditions, groundwater heat pumps use less energy than conventional heating and cooling equipment. Life-cycle cost comparisons with conventional equipment depend on alternative system choices and well cost options included in the groundwater heat pump system.

  17. Statistical analysis of factors affecting landslide distribution in the new Madrid seismic zone, Tennessee and Kentucky

    USGS Publications Warehouse

    Jibson, R.W.; Keefer, D.K.

    1989-01-01

    More than 220 large landslides along the bluffs bordering the Mississippi alluvial plain between Cairo, Ill., and Memphis, Tenn., are analyzed by discriminant analysis and multiple linear regression to determine the relative effects of slope height and steepness, stratigraphic variation, slope aspect, and proximity to the hypocenters of the 1811-12 New Madrid, Mo., earthquakes on the distribution of these landslides. Three types of landslides are analyzed: (1) old, coherent slumps and block slides, which have eroded and revegetated features and no active analogs in the area; (2) old earth flows, which are also eroded and revegetated; and (3) young rotational slumps, which are present only along near-river bluffs, and which are the only young, active landslides in the area. Discriminant analysis shows that only one characteristic differs significantly between bluffs with and without young rotational slumps: failed bluffs tend to have sand and clay at their base, which may render them more susceptible to fluvial erosion. Bluffs having old coherent slides are significantly higher, steeper, and closer to the hypocenters of the 1811-12 earthquakes than bluffs without these slides. Bluffs having old earth flows are likewise higher and closer to the earthquake hypocenters. Multiple regression analysis indicates that the distribution of young rotational slumps is affected most strongly by slope steepness: about one-third of the variation in the distribution is explained by variations in slope steepness. The distribution of old coherent slides and earth flows is affected most strongly by slope height, but the proximity to the hypocenters of the 1811-12 earthquakes also significantly affects the distribution. The results of the statistical analyses indicate that the only recently active landsliding in the area is along actively eroding river banks, where rotational slumps formed as bluffs are undercut by the river. The analyses further indicate that the old coherent slides

  18. Water color affects the stratification, surface temperature, heat content, and mean epilimnetic irradiance of small lakes

    USGS Publications Warehouse

    Houser, J.N.

    2006-01-01

    The effects of water color on lake stratification, mean epilimnetic irradiance, and lake temperature dynamics were examined in small, north-temperate lakes that differed widely in water color (1.5-19.8 m -1). Among these lakes, colored lakes differed from clear lakes in the following ways: (i) the epilimnia were shallower and colder, and mean epilimnetic irradiance was reduced; (ii) the diel temperature cycles were more pronounced; (iii) whole-lake heat accumulation during stratification was reduced. The depth of the epilimnion ranged from 2.5 m in the clearest lake to 0.75 m in the most colored lake, and 91% of the variation in epilimnetic depth was explained by water color. Summer mean morning epilimnetic temperature was ???2??C cooler in the most colored lake compared with the clearest lake. In clear lakes, the diel temperature range (1.4 ?? 0.7??C) was significantly (p = 0.01) less than that in the most colored lake (2.1 ?? 1.0??C). Change in whole-lake heat content was negatively correlated with water color. Increasing water color decreased light penetration more than thermocline depth, leading to reduced mean epilimnetic irradiance in the colored lakes. Thus, in these small lakes, water color significantly affected temperature, thermocline depth, and light climate. ?? 2006 NRC.

  19. Linking river, floodplain, and vadose zone hydrology to improve restoration of a coastal river affected by saltwater intrusion.

    PubMed

    Kaplan, D; Muñoz-Carpena, R; Wan, Y; Hedgepeth, M; Zheng, F; Roberts, R; Rossmanith, R

    2010-01-01

    Floodplain forests provide unique ecological structure and function, which are often degraded or lost when watershed hydrology is modified. Restoration of damaged ecosystems requires an understanding of surface water, groundwater, and vadose (unsaturated) zone hydrology in the floodplain. Soil moisture and porewater salinity are of particular importance for seed germination and seedling survival in systems affected by saltwater intrusion but are difficult to monitor and often overlooked. This study contributes to the understanding of floodplain hydrology in one of the last bald cypress [Taxodium distichum (L.) Rich.] floodplain swamps in southeast Florida. We investigated soil moisture and porewater salinity dynamics in the floodplain of the Loxahatchee River, where reduced freshwater flow has led to saltwater intrusion and a transition to salt-tolerant, mangrove-dominated communities. Twenty-four dielectric probes measuring soil moisture and porewater salinity every 30 min were installed along two transects-one in an upstream, freshwater location and one in a downstream tidal area. Complemented by surface water, groundwater, and meteorological data, these unique 4-yr datasets quantified the spatial variability and temporal dynamics of vadose zone hydrology. Results showed that soil moisture can be closely predicted based on river stage and topographic elevation (overall Nash-Sutcliffe coefficient of efficiency = 0.83). Porewater salinity rarely exceeded tolerance thresholds (0.3125 S m(-1)) for bald cypress upstream but did so in some downstream areas. This provided an explanation for observed vegetation changes that both surface water and groundwater salinity failed to explain. The results offer a methodological and analytical framework for floodplain monitoring in locations where restoration success depends on vadose zone hydrology and provide relationships for evaluating proposed restoration and management scenarios for the Loxahatchee River.

  20. Remote sensing for assessing the zone of benefit where deep drains improve productivity of land affected by shallow saline groundwater.

    PubMed

    Kobryn, H T; Lantzke, R; Bell, R; Admiraal, R

    2015-03-01

    The installation of deep drains is an engineering approach to remediate land salinised by the influence of shallow groundwater. It is a costly treatment and its economic viability is, in part, dependent on the lateral extent to which the drain increases biological productivity by lowering water tables and soil salinity (referred to as the drains' zone of benefit). Such zones may be determined by assessing the biological productivity response of adjacent vegetation over time. We tested a multi-temporal satellite remote sensing method to analyse temporal and spatial changes in vegetation condition surrounding deep drainage sites at five locations in the Western Australian wheatbelt affected by dryland salinity-Morawa, Pithara, Beacon, Narembeen and Dumbleyung. Vegetation condition as a surrogate for biological productivity was assessed by Normalised Difference Vegetation Index (NDVI) during the peak growing season. Analysis was at the site scale within a 1000 m buffer zone from the drains. There was clear evidence of NDVI increasing with elevation, slope and distance from the drain. After accounting for elevation, slope and distance from the drain, there was a significant increase in NDVI across the five locations after installation of deep drains. Changes in NDVI after drainage were broadly consistent with measured changes at each site in groundwater levels after installation of the deep drains. However, this study assessed the lateral extent of benefit for biological productivity and gave a measure of the area of benefit along the entire length of the drain. The method demonstrated the utility of spring NDVI images for rapid and relatively simple assessment of the change in site condition after implementation of drainage, but approaches for further improvement of the procedure were identified.

  1. Investigating changes of electrical characteristics of the saturated zone affected by hazardous organic waste

    NASA Astrophysics Data System (ADS)

    Frohlich, Reinhard K.; Barosh, Patrick J.; Boving, Thomas

    2008-03-01

    The Picillo Farm, EPA Superfund Site, in western Rhode Island was an unauthorized disposal site of hazardous organic chemicals. Predominantly organic contaminants have entered an aquifer comprised of layered glacial deposits and fractured bedrock and spread past the site boundaries with groundwater flow. Hydraulic conductivities in the glacial deposits range over two orders of magnitude and fractures and faults in the granitic bedrock further complicate the spreading of contaminants. Monitoring wells delineate two plumes that extend towards a fault-controlled valley with lakes and wetlands; one to the northwest and the other to the southwest. In this investigation we studied the electrical characteristics of both plumes. One dimensional Schlumberger depth soundings were conducted along several profile lines over the plumes and compared to those over non-contaminated sections of the site. With regard to the southwestern plume, high formation factors (ratio of bulk layer to pore water resistivity) between 12 and 45 were observed compared to values between 2.5 and 7.7 measured over the non-contaminated sections. Also, high values (> 5) of vertical electrical anisotropy (ratio of geoelectrically determined depth to high resistivity bedrock to drilled depth to bedrock) were measured over the contaminated part of the site. These values are extremely high compared to other non-contaminated sites (range: 2 to 3) in glacial stream channels of southern Rhode Island. Geoelectric measurements were affected by lateral effects. However, the consistency of high formation factors (11 to 35) and high vertical anisotropies (3 to 5) over the southwestern plume in comparison to low formation factors (3 to 8) and vertical anisotropies (1 to 1.5) over non-contaminated sites represents a marked difference between both sites. Overall, the Schlumberger depth soundings are less susceptible to near-surface lateral inhomogeneities than expected from other geoelectrical methods. Also, the

  2. Factors affecting the quality of fish caught by Native Americans in the Zone 6 fishery 1991 through 1993

    SciTech Connect

    Abernethy, C.S.

    1994-09-01

    A program to monitor the salmon and steelhead (Oncorhynchus spp.) fishery in the lower Columbia River (Zone 6 fishery) was initiated in 1991 to respond to questions and comments frequently made by Native Americans at public meetings. Native Americans were concerned that the quality of the Columbia River had deteriorated and that the poor environmental conditions had affected the health and quality of fish they relied on for subsistence, ceremonial, religious, and commercial purposes. They also feared that eating contaminated fish might endanger the health of their children and future generations. Operations at the Hanford Site were listed as one of many causes of the deteriorating environment. Fisheries pathologists concluded that most of the external symptoms on fish were related to bacterial infection of gill net abrasions and pre-spawning trauma, and were not caused by pollution or contamination of the Columbia River. The pathologists also stated that consumption of the fish posed no threat to human consumers.

  3. The role of diabatic heating in maintaining the upper-tropospheric baroclinic zone in the South Pacific

    NASA Technical Reports Server (NTRS)

    Robertson, Franklin R.; Vincent, Dayton G.; Kann, Deirdre M.

    1989-01-01

    The four-dimensional structure of the region in the South Pacific convergence zone (SPCZ) during January 10-18, 1979 is studied using a modified set of ECMWF FGGE level III-b analyses. The effects of kinematic and thermodynamic processes on maintaining the upper baroclinic region corresponding with the subtropical jet are analyzed. The role of adiabatic and diabatic processes in the maintenance of baroclinicity in the area of the SPCZ is examined using the frontogenetical function. It is observed that the processes affecting the evolution of baroclinicity in the SPCZ region differ from those in the middle latitude; possible reasons for these differences are proposed.

  4. Geothermal Frontier: Penetrate a boundary between hydrothermal convection and heat conduction zones to create 'Beyond Brittle Geothermal Reservoir'

    NASA Astrophysics Data System (ADS)

    Tsuchiya, N.; Asanuma, H.; Sakaguchi, K.; Okamoto, A.; Hirano, N.; Watanabe, N.; Kizaki, A.

    2013-12-01

    EGS has been highlightened as a most promising method of geothermal development recently because of applicability to sites which have been considered to be unsuitable for geothermal development. Meanwhile, some critical problems have been experimentally identified, such as low recovery of injected water, difficulties to establish universal design/development methodology, and occurrence of large induced seismicity. Future geothermal target is supercritical and superheated geothermal fluids in and around ductile rock bodies under high temperatures. Ductile regime which is estimated beyond brittle zone is target region for future geothermal development due to high enthalpy fluids and relatively weak water-rock interaction. It is very difficult to determine exact depth of Brittle-Ductile boundary due to strong dependence of temperature (geotherm) and strain rate, however, ductile zone is considered to be developed above 400C and below 3 km in geothermal fields in Tohoku District. Hydrothermal experiments associated with additional advanced technology will be conducting to understand ';Beyond brittle World' and to develop deeper and hotter geothermal reservoir. We propose a new concept of the engineered geothermal development where reservoirs are created in ductile basement, expecting the following advantages: (a)simpler design and control the reservoir, (b)nearly full recovery of injected water, (c)sustainable production, (d)cost reduction by development of relatively shallower ductile zone in compression tectonic zones, (e)large quantity of energy extraction from widely distributed ductile zones, (f)establishment of universal and conceptual design/development methodology, and (g) suppression of felt earthquakes from/around the reservoirs. In ductile regime, Mesh-like fracture cloud has great potential for heat extraction between injection and production wells in spite of single and simple mega-fracture. Based on field observation and high performance hydrothermal

  5. The role of diabatic heating in maintaining the upper-tropospheric baroclinic zone in the South Pacific

    NASA Technical Reports Server (NTRS)

    Robertson, Franklin R.; Vincent, Dayton G.; Kann, Deirdre M.

    1989-01-01

    The four-dimensional structure of a region that encompasses the South Pacific Convergence Zone (SPCZ) is presently examined using a modified set of FGGE level III-b analyses, during the January 10-18, 1979 period when two cyclones formed in the tropics and propagated southeastward along the SPCZ to middle latitudes. An effort is made to ascertain the significance of kinematic and thermodynamic processes in maintaining the the upper baroclinic region coincident with the subtropical jet. A partitioned form of the frontogenetical function, used to diagnose the adiabatic and diabatic contributions to the maintenance of baroclinicity in the SPCZ's vicinity, indicates a major balance between the frontogenetical contribution by differential diabatic heating and the opposing diabatic tilting processes.

  6. The Influence of Static and Rotating Magnetic Fields on Heat and Mass Transfer in Silicon Floating Zones

    NASA Technical Reports Server (NTRS)

    Croell, Arne; Dold, P.; Kaiser, Th.; Szofran, Frank; Benz, K. W.

    1999-01-01

    Hear and mass transfer in float-zone processing are strongly influenced by convective flows in the zone. They are caused by buoyancy convection, thermocapillary (Marangoni) convection, or artificial sources such as rotation and radio frequency heating. Flows in conducting melts can be controlled by the use of magnetic fields, either by damping fluid motion with static fields or by generating a def@ned flow with rotating fields. The possibilities of using static and rotating magnetic fields in silicon floating-zone growth have been investigated by experiments in axial static fields up to ST and in transverse rotating magnetic fields up to 7.S mT. Static fields of a few 100 MT already suppress most striations but are detrimental to the radial segregation by introducing a coring effect. A complete suppression of dopant striations caused by time-dependent thermocapillary convection and a reduction of the coring to insignificant values, combined with a shift of the axial segregation profile towards a more diffusion-limited case, is possible with static fields ? 1T. However, under certain conditions the use of high axial magnetic fields can lead to the appearance of a new type of pronounced dopant striations, caused by thermoelec:romagnetic convection. The use of a transverse rotating magnetic field influences the microscopic segregation at quite low inductions, of the order of a few mT. The field shifts time-dependent flows and the resulting striation patterns from a broad range of low frequencies at high amplitudes to a few high frequencies at low amplitudes

  7. Behavioural Responses to Thermal Conditions Affect Seasonal Mass Change in a Heat-Sensitive Northern Ungulate

    PubMed Central

    van Beest, Floris M.; Milner, Jos M.

    2013-01-01

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

  8. Are Advecting Processes in the Vadose Zone of the Albuquerque Basin Altering the Conductive Heat Transfer Signal From Surface Temperature Change ?

    NASA Astrophysics Data System (ADS)

    Reiter, M. A.

    2004-12-01

    Temperature measurements ( T logs ) in the deep vadose zone ( about 60m to 120m depth ) of the Albuquerque Basin have been repeated over the past year at four piezometer nests. The measurements were made with a very fast time response thermistor, which allowed data to be taken every meter going down hole. This depth resolution of temperature data permits a rather detailed observation of the thermal regime in the vadose zone. At one site ( Lincoln Middle School ) the temperature profile below 20m clearly shows a conductive profile resulting from surface temperature change due to urbanization and nearby ( about 10m ) asphalt pavement. At the other three sites the cause of non-linearity in the T log is less certain. Temperature records suggest about 1 deg C increase in near surface air temperature over the past thirty years at the Albuquerque airport; although this data may also be affected by urbanization. The Tome and 98th Street sites are being approached by paved roads and urbanization. At the Tome site expressions representing horizontal advection are the statistically preferred fit to the T log from about 25m to 58m ( F statistic ). At the 98th Street site an expression representing a surface temperature step best fits the T log from 20m to about 75m; however, the temperature step (about 1 deg C to 2 deg C, 3 to 15 yr ago ) is variable between logs, and the profile of the T log with abrupt discontinuities may suggest other than just conductive heat transfer. The fourth piezometer nest at the Mesa del Sol site is the most remote of the sites considered, with as little nearby surface disturbance as might be expected for a drilling location. At depths between 30m and 70m the expressions representing surface temperature change, horizontal advection, and vertical advection, all fit the T log reasonably well. The temperature step expression suggests about 1 deg C to 1.8 deg C surface temperature increase about 13 yr to 28 yr ago. Deeper in the vadose zone, from about

  9. Dam heat load affects neonatal calves’ bacterial prevalence and innate immunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress is known to suppress animal’s immunity, making them more susceptible to bacterial infections. In Indiana, field observations showed that calves have greater morbidity and mortality when they are born after a heat event. Objectives of this study were to determine whether heat load increas...

  10. Affect of Air Leakage into a Thermal-Vacuum Chamber on Helium Refrigeration Heat Load

    NASA Technical Reports Server (NTRS)

    Garcia, Sam; Meagher, Daniel; Linza, Robert; Saheli, Fariborz; Vargas, Gerardo; Lauterbach, John; Reis, Carl; Ganni, Venkatarao (Rao); Homan, Jonathan

    2008-01-01

    NASA s Johnson Space Center (JSC) Building 32 houses two large thermal-vacuum chambers (Chamber A and Chamber B). Within these chambers are liquid nitrogen shrouds to provide a thermal environment and helium panels which operate at 20K to provide cryopumping. Some amount of air leakage into the chambers during tests is inevitable. This causes "air fouling" of the helium panel surfaces due to the components of the air that adhere to the panels. The air fouling causes the emittance of the helium panels to increase during tests. The increase in helium panel emittance increases the heat load on the helium refrigerator that supplies the 20K helium for those panels. Planning for thermal-vacuum tests should account for this increase to make sure that the helium refrigerator capacity will not be exceeded over the duration of a test. During a recent test conducted in Chamber B a known-size air leak was introduced to the chamber. Emittance change of the helium panels and the affect on the helium refrigerator was characterized. A description of the test and the results will be presented.

  11. Effects of Heat Stress on the Well-Being, Fertility, and Hatchability of Chickens in the Northern Guinea Savannah Zone of Nigeria: A Review

    PubMed Central

    Ayo, J. O.; Obidi, J. A.; Rekwot, P. I.

    2011-01-01

    The paper examines heat stress and its adverse effects as a hindrance to profitable poultry production in the tropics, with emphasis on the Northern Guinea Savannah zone of Nigeria. It elucidates the general negative effects of heat stress on physiological parameters of domestic chickens, and the specific impact of the stress on reproduction in the tropics. The deleterious effects are expressed in poor poultry well-being and reproductive performance. It is concluded that measures aimed at alleviating heat stress in domestic chickens must be adopted in order to enhance reproductive and, consequently, efficiency of modern poultry production in the tropics. PMID:23738109

  12. Utility of bromide and heat tracers for aquifer characterization affected by highly transient flow conditions

    NASA Astrophysics Data System (ADS)

    Ma, Rui; Zheng, Chunmiao; Zachara, John M.; Tonkin, Matthew

    2012-08-01

    A tracer test using both bromide and heat tracers conducted at the Integrated Field Research Challenge site in Hanford 300 Area (300A), Washington, provided an instrument for evaluating the utility of bromide and heat tracers for aquifer characterization. The bromide tracer data were critical to improving the calibration of the flow model complicated by the highly dynamic nature of the flow field. However, most bromide concentrations were obtained from fully screened observation wells, lacking depth-specific resolution for vertical characterization. On the other hand, depth-specific temperature data were relatively simple and inexpensive to acquire. However, temperature-driven fluid density effects influenced heat plume movement. Moreover, the temperature data contained "noise" caused by heating during fluid injection and sampling events. Using the hydraulic conductivity distribution obtained from the calibration of the bromide transport model, the temperature depth profiles and arrival times of temperature peaks simulated by the heat transport model were in reasonable agreement with observations. This suggested that heat can be used as a cost-effective proxy for solute tracers for calibration of the hydraulic conductivity distribution, especially in the vertical direction. However, a heat tracer test must be carefully designed and executed to minimize fluid density effects and sources of noise in temperature data. A sensitivity analysis also revealed that heat transport was most sensitive to hydraulic conductivity and porosity, less sensitive to thermal distribution factor, and least sensitive to thermal dispersion and heat conduction. This indicated that the hydraulic conductivity remains the primary calibration parameter for heat transport.

  13. Coloration affects heating and cooling in three color morphs of the Australian bluetongue lizard, Tiliqua scincoides.

    PubMed

    Geen, Michael R S; Johnston, Gregory R

    2014-07-01

    The color-mediated thermoregulation hypothesis predicts that dark body color (low reflectance) allows organisms to gain heat more efficiently than does pale coloration (high reflectance). This prediction is intuitive and widely assumed to be true, but has poor empirical support. We used rare, captive-bred, mutant melanistic, albino and wild-type Australian bluetongue lizards, Tiliqua scincoides to measure the effects of skin reflectance on the heating and cooling rates. We measured heating under an artificial radiant heat source and cooling rates in an ice-cooled box using live lizards in a room with still air. The effect of skin reflectance on heat transfer was clear, despite the substantial influence of body size. Melanistic T. scincoides showed low reflectance and gained heat faster than highly reflective albinos. Melanistic lizards also lost heat faster than albinos. Wild-type lizards were intermediate in reflectance, gained heat at rates indistinguishable from melanistic lizards, and lost heat at rates indistinguishable from albino lizards. This study system allowed us to control for variables that were confounded in other studies and may explain the inconsistent support for the color-mediated thermoregulation hypothesis. Our results provide clear evidence that skin reflectance influences the rate of heating and cooling in ectotherms.

  14. Functional properties of whey proteins affected by heat treatment and hydrodynamic high-pressure shearing.

    PubMed

    Dissanayake, M; Vasiljevic, T

    2009-04-01

    Two batches of native whey proteins (WP) were subjected to microfluidization or heat denaturation accompanied by microfluidization, followed by spray drying. Powders were assessed for their solubility, heat stability, coagulation time, and emulsifying and foaming properties. Effects of denaturation and shearing were examined by particle size analysis, differential scanning calorimetry, reducing and nonreducing sodium dodecyl sulfate-PAGE, and size exclusion-HPLC. Heat treatment significantly decreased solubility, whereas the number of microfluidization passes markedly improved solubility. The combined effect of heat and pressure significantly increased heat coagulation time. Emulsifying activity index substantially increased upon heat denaturation and was further enhanced by microfluidization. Emulsion stability appeared unaffected by the combined treatment, but the concentration of adsorbed protein on fat droplets was significantly increased. Foaming properties were diminished by heating. Particle size distribution patterns, sodium dodecyl sulfate-PAGE, and size exclusion-HPLC revealed disappearance of major WP and creation of relatively higher, as well as smaller, molecular weight aggregates as a result of the 2 treatments. The use of heat and microfluidization in combination could be used to stabilize WP against heat by producing microparticulated species that have different surface and colloidal properties compared with native WP. These results have implications for the use of WP as an additive in heat-processed foods.

  15. SIMS evaluation of poly crystal boron nitride tool effect in thermo-mechanically affected zone of friction stir weld steels

    NASA Astrophysics Data System (ADS)

    Kim, JaeNam; Lee, SangUp; Kwun, HyoegDae; Shin, KwangSoo; Kang, ChangYong

    2014-11-01

    The effect of the poly crystal boron nitride (PCBN) tool in friction stir weld (FSW) steels was evaluated using the secondary ion mass spectroscopy (SIMS) technique. This study focused on the quantitative SIMS analysis of impurity boron through a resistive anode encoder (RAE) image. The RAE images were transformed retrospective depth profile by profiler. The relative sensitivity factors (RSFs) for boron varied heavily according to by the polarity of secondary voltage and matrix materials. The RAE images of cluster-polyatomic secondary ion species, 11B16O2, properly map the distribution of impurity boron in the thermo-mechanically affected zone (TMAZ) of FSW steels using negative secondary polarity 4.5 kV. A combination of cluster-polyatomic ion, 11B16O2 and 56Fe16O provided a good calibration curve by 3 SRMs with the least matrix effect. The boron concentrations of TMAZ in FSW steels were determined through the calibration curve by taking the corresponding boron concentration value (CB) of the intensity ratio (Ii/Im) from unknown samples. The new SIMS quantification technique of impurity boron from RAE images is found to be effective for a more quantitative understanding of the wear mechanism of the PCBN tool in TMAZ of FSW steels.

  16. Recovery approach affects soil quality in the water level fluctuation zone of the Three Gorges Reservoir, China: implications for revegetation.

    PubMed

    Ye, Chen; Cheng, Xiaoli; Zhang, Quanfa

    2014-02-01

    Plants in the water level fluctuation zone of the Three Gorges Reservoir Region disappeared due to winter-flooding and prolonged inundation. Revegetation (plantation and natural recovery) have been promoted to restore and protect the riparian ecosystem in recent years. Revegetation may affect soil qualities and have broad important implications both for ecological services and soil recovery. In this study, we investigated soil properties including soil pH values, bulk density, soil organic matter (SOM), soil nutrients and heavy metals, soil microbial community structure, microbial biomass, and soil quality index under plantation and natural recovery in the Three Gorges Reservoir Region. Most soil properties showed significant temporal and spatial variations in both the plantation and natural recovery areas. Higher contents of SOM and NO3-N were found in plantation area, while higher contents of soil pH values, bulk density, and total potassium were observed in the natural recovery area. However, there were no significant differences in plant richness and diversity and soil microbial community structure between the two restoration approaches. A soil quality index derived from SOM, bulk density, Zn, Cd, and Hg indicated that natural recovery areas with larger herbaceous coverage had more effective capacity for soil restoration.

  17. Recovery of Heat Treated Bacillus cereus Spores Is Affected by Matrix Composition and Factors with Putative Functions in Damage Repair

    PubMed Central

    Warda, Alicja K.; Tempelaars, Marcel H.; Abee, Tjakko; Nierop Groot, Masja N.

    2016-01-01

    The ability of spores to recover and grow out after food processing is affected by cellular factors and by the outgrowth conditions. In the current communication we studied the recovery and outgrowth of individually sorted spores in BHI and rice broth media and on agar plates using flow cytometry. We show that recovery of wet heat treated Bacillus cereus ATCC 14579 spores is affected by matrix composition with highest recovery in BHI broth or on rice agar plates, compared to BHI agar plates and rice broth. Data show that not only media composition but also its liquid or solid state affect the recovery of heat treated spores. To determine the impact of factors with putative roles in recovery of heat treated spores, specific genes previously shown to be highly expressed in outgrowing heat-treated spores were selected for mutant construction. Spores of nine B. cereus ATCC 14579 deletion mutants were obtained and their recovery from wet heat treatment was evaluated using BHI and rice broth and agar plates. Deletion mutant spores showed different capacity to recover from heat treatment compared to wild type with the most pronounced effect for a mutant lacking BC5242, a gene encoding a membrane protein with C2C2 zinc finger which resulted in over 95% reduction in recovery compared to the wild type in BHI broth. Notably, similar relative performance of wild type and mutants was observed using the other recovery conditions. We obtained insights on the impact of matrix composition and state on recovery of individually sorted heat treated spores and identified cellular factors with putative roles in this process. These results may provide leads for future developments in design of more efficient combined preservation treatments. PMID:27486443

  18. Factors Affecting Release of Heat-Labile Enterotoxin by Enterotoxigenic Escherichia coli

    PubMed Central

    Kunkel, Steven L.; Robertson, Donald C.

    1979-01-01

    Various conditions affecting the release of heat-labile enterotoxin (LT) by enterotoxigenic Escherichia coli have been examined. The pH of a defined medium containing three amino acids, M-9 salts, and 0.5% glucose decreased to less than 7.0 in early log phase of growth, and no extracellular LT was detected. Adjustment of the pH at 8 h from 6.0 to 8.0 resulted in a concomitant increase in LT activity in culture supernatants. The release of cell-associated LT was significantly reduced by preincubation with protease inhibitors and increased by preincubation with trypsin. Cell-associated LT was not released by pH adjustment of cells grown at 21°C; however, polymyxin B treatment released a toxin species active in only the pigeon erythrocyte lysate (PEL) assay system. As the growth temperature was increased, polymyxin B released toxin species which exhibited both PEL and Y-1 adrenal tumor cell activity. Polymyxin B extracts of enterotoxigenic E. coli in early log phase grown at 37°C possessed only PEL activity, whereas extracts from cells in late-log and stationary phases had biological activity in both assay systems. Also, LT released by pH adjustment from mid-log to stationary phase was active in both PEL and Y-1 adrenal tumor cell assays. Gel electrophoresis of polymyxin B extracts revealed at least three molecular weight species active in either the PEL (22,000 daltons and 30,000 daltons) or both the PEL and the Y-1 adrenal tumor cell assay (72,000 daltons), depending on the growth temperature. These observations may help to explain the chemical and biological heterogeneity of most LT preparations and facilitate purification of LT by increasing the yield of enterotoxin. PMID:37162

  19. Seroepidemiology of heat-labile enterotoxigenic Escherichia coli and Norwalk virus infections in Panamanians, Canal Zone residents, Apache Indians, and United States Peace Corps volunteers.

    PubMed

    Ryder, R W; Greenberg, H; Singh, N; Oro, G; de Guardia, A; Sack, R B; Kapikian, A Z

    1982-09-01

    Serum antibody titrations against the heat-labile enterotoxin (LT) of Escherichia coli were carried out on Panamanians, U.S. citizens resident in the Panama Canal Zone, Apache Indians living on the reservation in Whiteriver, Arizona, and Peace Corps volunteers before they traveled overseas. Antibody titers to Norwalk virus were also carried out on serum from Panamanian and Canal Zone residents. A high prevalence of low-titer LT antibodies was found in infants and adults from Panama, the Canal Zone, and Whiteriver. Panamanian children aged 1 to 5 years had the highest LT antibody titers. Peace Corps volunteers had a low prevalence and titer of LT antibodies. Prevalence and titer of antibodies to Norwalk virus were generally higher in Panamanians compared with Canal Zone residents of the same age. In the populations we studied, various modes of transmission and mechanisms of immunity likely explain the differences which we observed in antibody prevalence and titer to these two enteric pathogens.

  20. Influence of gravitational and vibrational convection on the heat- and mass transfer in the melt during crystal growing by Bridgman and floating zone methods

    NASA Astrophysics Data System (ADS)

    Fedorov, Oleg

    2016-07-01

    Space materials science is one of the priorities of different national and international space programs. The physical processes of heat and mass transfer in microgravity (including effect of g-jitter) is far from complete clarity, especially for important practical technology for producing crystals from the melt. The idea of the impact on crystallizing melt by low frequency vibration includes not only the possibility to suppress unwanted microaccelerations, but also to actively influence the structure of the crystallization front. This approach is one of the most effective ways to influence the quality of materials produced in flight conditions. The subject of this work is the effect of vibrations on the thermal and hydrodynamic processes during crystal growth using Bridgman and floating zone techniques, which have the greatest prospect of practical application in space. In the present approach we consider the gravitational convection, Marangoni convection, as well as the effect of vibration on the melt for some special cases. The results of simulation were compared with some experimental data obtained by the authors using a transparent model substance - succinonitrile (Bridgman method), and silicon (floating zone method). Substances used, process parameters and characteristics of the experimental units correspond the equipment developed for onboard research and serve as a basis for selecting optimum conditions vibration exposure as a factor affecting the solidification pattern. The direction of imposing vibrations coincides with the axis of the crystal, the frequency is presented by the harmonic law, and the force of gravity was varied by changing its absolute value. Mathematical model considered axisymmetric approximation of joint convective-conductive energy transfer in the system crystal - melt. Upon application of low-frequency oscillations of small amplitude along the axis of growing it was found the suppression of the secondary vortex flows near the

  1. Heat stability and acid gelation properties of calcium-enriched reconstituted skim milk affected by ultrasonication.

    PubMed

    Chandrapala, Jayani; Bui, Don; Kentish, Sandra; Ashokkumar, Muthupandian

    2014-05-01

    The aggregation of proteins after heating of calcium-fortified milks has been an ongoing problem in the dairy industry. This undesirable effect restricts the manufacture of calcium rich dairy products. To overcome this problem, a completely new approach in controlling the heat stability of dairy protein solutions, developed in our lab, has been employed. In this approach, high intensity, low frequency ultrasound is applied for a very short duration after a pre-heating step at ⩾70 °C. The ultrasound breaks apart whey/whey and whey/casein aggregates through the process of acoustic cavitation. Protein aggregates do not reform on subsequent post-heating, thereby making the systems heat stable. In this paper, the acid gelation properties of ultrasonicated calcium-enriched skim milks have also been investigated. It is shown that ultrasonication alone does not change the gelation properties significantly whereas a sequence of preheating (72 °C/1 min) followed by ultrasonication leads to decreased gelation times, decreased gel syneresis and increased skim milk viscosity in comparison to heating alone. Overall, ultrasonication has the potential to provide calcium-fortified dairy products with increased heat stability. However, enhanced gelation properties can only be achieved when ultrasonication is completed in conjunction with heating.

  2. Pre-natal heat load affects bacterial levels and innate immunity in neonatal calves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress suppresses immunity, making animals more susceptible to bacterial infections. Additionally, field observations suggest that calves have greater morbidity and mortality when they are born after a heat event. However, scientific evidence is still lacking, limiting the development of target...

  3. Utility of Bromide and Heat Tracers for Aquifer Characterization Affected by Highly Transient Flow Conditions

    SciTech Connect

    Ma, Rui; Zheng, Chunmiao; Zachara, John M.; Tonkin, Matthew J.

    2012-08-29

    A tracer test using both bromide and heat tracers conducted at the Integrated Field Research Challenge site in Hanford 300 Area (300A), Washington, provided an instrument for evaluating the utility of bromide and heat tracers for aquifer characterization. The bromide tracer data were critical to improving the calibration of the flow model complicated by the highly dynamic nature of the flow field. However, most bromide concentrations were obtained from fully screened observation wells, lacking depth-specific resolution for vertical characterization. On the other hand, depth-specific temperature data were relatively simple and inexpensive to acquire. However, temperature-driven fluid density effects influenced heat plume movement. Moreover, the temperature data contained “noise” caused by heating during fluid injection and sampling events. Using the hydraulic conductivity distribution obtained from the calibration of the bromide transport model, the temperature depth profiles and arrival times of temperature peaks simulated by the heat transport model were in reasonable agreement with observations. This suggested that heat can be used as a cost-effective proxy for solute tracers for calibration of the hydraulic conductivity distribution, especially in the vertical direction. However, a heat tracer test must be carefully designed and executed to minimize fluid density effects and sources of noise in temperature data. A sensitivity analysis also revealed that heat transport was most sensitive to hydraulic conductivity and porosity, less sensitive to thermal distribution factor, and least sensitive to thermal dispersion and heat conduction. This indicated that the hydraulic conductivity remains the primary calibration parameter for heat transport.

  4. Oligonol Supplementation Affects Leukocyte and Immune Cell Counts after Heat Loading in Humans

    PubMed Central

    Lee, Jeong Beom; Shin, Young Oh

    2014-01-01

    Oligonol is a low-molecular-weight form of polyphenol and has antioxidant and anti-inflammatory activity, making it a potential promoter of immunity. This study investigates the effects of oligonol supplementation on leukocyte and immune cell counts after heat loading in 19 healthy male volunteers. The participants took a daily dose of 200 mg oligonol or a placebo for 1 week. After a 2-week washout period, the subjects were switched to the other study arm. After each supplement, half-body immersion into hot water was made, and blood was collected. Then, complete and differential blood counts were performed. Flow cytometry was used to enumerate and phenotype lymphocyte subsets. Serum concentrations of interleukin (IL)-1β and IL-6 in blood samples were analyzed. Lymphocyte subpopulation variables included counts of total T cells, B cells, and natural killer (NK) cells. Oligonol intake attenuated elevations in IL-1β (an 11.1-fold change vs. a 13.9-fold change immediately after heating; a 12.0-fold change vs. a 12.6-fold change 1h after heating) and IL-6 (an 8.6-fold change vs. a 9.9-fold change immediately after heating; a 9.1-fold change vs. a 10.5-fold change 1h after heating) immediately and 1 h after heating in comparison to those in the placebo group. Oligonol supplementation led to significantly higher numbers of leukocytes (a 30.0% change vs. a 21.5% change immediately after heating; a 13.5% change vs. a 3.5% change 1h after heating) and lymphocytes (a 47.3% change vs. a 39.3% change immediately after heating; a 19.08% change vs. a 2.1% change 1h after heating) relative to those in the placebo group. Oligonol intake led to larger increases in T cells, B cells, and NK cells at rest (p < 0.05, p < 0.05, and p < 0.001, respectively) and immediately after heating (p < 0.001) in comparison to those in the placebo group. In addition, levels of T cells (p < 0.001) and B cells (p < 0.001) were significantly higher 1 h after heating in comparison to those in the

  5. Characterization of 4H <000-1> Silicon Carbide Films Grown by Solvent-Laser Heated Floating Zone

    NASA Technical Reports Server (NTRS)

    Woodworth, Andrew, A; Sayir, Ali; Neudeck, Philip, G; Raghothamachar, Balaji; Dudley, Michael

    2012-01-01

    Commercially available bulk silicon carbide (SiC) has a high number (>2000/sq cm) of screw dislocations (SD) that have been linked to degradation of high-field power device electrical performance properties. Researchers at the NASA Glenn Research Center have proposed a method to mass-produce significantly higher quality bulk SiC. In order for this bulk growth method to become reality, growth of long single crystal SiC fibers must first be achieved. Therefore, a new growth method, Solvent-Laser Heated Floating Zone (Solvent-LHFZ), has been implemented. While some of the initial Solvent-LHFZ results have recently been reported, this paper focuses on further characterization of grown crystals and their growth fronts. To this end, secondary ion mass spectroscopy (SIMS) depth profiles, cross section analysis by focused ion beam (FIB) milling and mechanical polishing, and orientation and structural characterization by x-ray transmission Laue diffraction patterns and x-ray topography were used. Results paint a picture of a chaotic growth front, with Fe incorporation dependant on C concentration.

  6. BAG3 affects the nucleocytoplasmic shuttling of HSF1 upon heat stress

    SciTech Connect

    Jin, Young-Hee; Ahn, Sang-Gun; Kim, Soo-A.

    2015-08-21

    Bcl2-associated athoanogene (BAG) 3 is a member of the co-chaperone BAG family. It is induced by stressful stimuli such as heat shock and heavy metals, and it regulates cellular adaptive responses against stressful conditions. In this study, we identified a novel role for BAG3 in regulating the nuclear shuttling of HSF1 during heat stress. The expression level of BAG3 was induced by heat stress in HeLa cells. Interestingly, BAG3 rapidly translocalized to the nucleus upon heat stress. Immunoprecipitation assay showed that BAG3 interacts with HSF1 under normal and stressed conditions and co-translocalizes to the nucleus upon heat stress. We also demonstrated that BAG3 interacts with HSF1 via its BAG domain. Over-expression of BAG3 down-regulates the level of nuclear HSF1 by exporting it to the cytoplasm during the recovery period. Depletion of BAG3 using siRNA results in reduced nuclear HSF1 and decreased Hsp70 promoter activity. BAG3 in MEF(hsf1{sup −/−}) cells actively translocalizes to the nucleus upon heat stress suggesting that BAG3 plays a key role in the processing of the nucleocytoplasmic shuttling of HSF1 upon heat stress. - Highlights: • The expression level of BAG3 is induced by heat stress. • BAG3 translocates to the nucleus upon heat stress. • BAG3 interacts with HSF1 and co-localizes to the nucleus. • BAG3 is a key regulator for HSF1 nuclear shuttling.

  7. Textural and rheological properties of Pacific whiting surimi as affected by nano-scaled fish bone and heating rates.

    PubMed

    Yin, Tao; Park, Jae W

    2015-08-01

    Textural and rheological properties of Pacific whiting (PW) surimi were investigated at various heating rates with the use of nano-scaled fish bone (NFB) and calcium chloride. Addition of NFB and slow heating improved gel strength significantly. Activity of endogenous transglutaminase (ETGase) from PW surimi was markedly induced by both NFB calcium and calcium chloride, showing an optimal temperature at 30°C. Initial storage modulus increased as NFB calcium concentration increased and the same trend was maintained throughout the temperature sweep. Rheograms with temperature sweep at slow heating rate (1°C/min) exhibited two peaks at ∼ 35°C and ∼ 70°C. However, no peak was observed during temperature sweep from 20 to 90°C at fast heating rate (20°C/min). Protein patterns of surimi gels were affected by both heating rate and NFB calcium concentration. Under slow heating, myosin heavy chain intensity decreased with NFB calcium concentration, indicating formation of ε-(γ-glutamyl) lysine cross-links by ETGase and NFB calcium ion.

  8. Mortality during a Large-Scale Heat Wave by Place, Demographic Group, Internal and External Causes of Death, and Building Climate Zone

    PubMed Central

    Joe, Lauren; Hoshiko, Sumi; Dobraca, Dina; Jackson, Rebecca; Smorodinsky, Svetlana; Smith, Daniel; Harnly, Martha

    2016-01-01

    Mortality increases during periods of elevated heat. Identification of vulnerable subgroups by demographics, causes of death, and geographic regions, including deaths occurring at home, is needed to inform public health prevention efforts. We calculated mortality relative risks (RRs) and excess deaths associated with a large-scale California heat wave in 2006, comparing deaths during the heat wave with reference days. For total (all-place) and at-home mortality, we examined risks by demographic factors, internal and external causes of death, and building climate zones. During the heat wave, 582 excess deaths occurred, a 5% increase over expected (RR = 1.05, 95% confidence interval (CI) 1.03–1.08). Sixty-six percent of excess deaths were at home (RR = 1.12, CI 1.07–1.16). Total mortality risk was higher among those aged 35–44 years than ≥65, and among Hispanics than whites. Deaths from external causes increased more sharply (RR = 1.18, CI 1.10–1.27) than from internal causes (RR = 1.04, CI 1.02–1.07). Geographically, risk varied by building climate zone; the highest risks of at-home death occurred in the northernmost coastal zone (RR = 1.58, CI 1.01–2.48) and the southernmost zone of California’s Central Valley (RR = 1.43, CI 1.21–1.68). Heat wave mortality risk varied across subpopulations, and some patterns of vulnerability differed from those previously identified. Public health efforts should also address at-home mortality, non-elderly adults, external causes, and at-risk geographic regions. PMID:27005646

  9. Mortality during a Large-Scale Heat Wave by Place, Demographic Group, Internal and External Causes of Death, and Building Climate Zone.

    PubMed

    Joe, Lauren; Hoshiko, Sumi; Dobraca, Dina; Jackson, Rebecca; Smorodinsky, Svetlana; Smith, Daniel; Harnly, Martha

    2016-03-09

    Mortality increases during periods of elevated heat. Identification of vulnerable subgroups by demographics, causes of death, and geographic regions, including deaths occurring at home, is needed to inform public health prevention efforts. We calculated mortality relative risks (RRs) and excess deaths associated with a large-scale California heat wave in 2006, comparing deaths during the heat wave with reference days. For total (all-place) and at-home mortality, we examined risks by demographic factors, internal and external causes of death, and building climate zones. During the heat wave, 582 excess deaths occurred, a 5% increase over expected (RR = 1.05, 95% confidence interval (CI) 1.03-1.08). Sixty-six percent of excess deaths were at home (RR = 1.12, CI 1.07-1.16). Total mortality risk was higher among those aged 35-44 years than ≥ 65, and among Hispanics than whites. Deaths from external causes increased more sharply (RR = 1.18, CI 1.10-1.27) than from internal causes (RR = 1.04, CI 1.02-1.07). Geographically, risk varied by building climate zone; the highest risks of at-home death occurred in the northernmost coastal zone (RR = 1.58, CI 1.01-2.48) and the southernmost zone of California's Central Valley (RR = 1.43, CI 1.21-1.68). Heat wave mortality risk varied across subpopulations, and some patterns of vulnerability differed from those previously identified. Public health efforts should also address at-home mortality, non-elderly adults, external causes, and at-risk geographic regions.

  10. Contents and toxicity of heavy metals in soils of the zone affected by aerial emissions from the Severonikel Enterprise

    NASA Astrophysics Data System (ADS)

    Evdokimova, G. A.; Kalabin, G. V.; Mozgova, N. P.

    2011-02-01

    In 2009, the zoning of the terrestrial ecosystems in the area exposed to aerial emissions from the Severonikel Enterprise (Murmansk oblast) was performed on the basis of the parameters characterizing the state of the soils, including the contents of the main heavy metal pollutants and exchangeable calcium and magnesium, the soils' pH, the ratio of the organic to mineral soil components, and the state of the soils' microbiota. Three zones differing in the degree of the soil pollution were delimited. These were the zones of heavy, moderate, and weak pollution, which extended for up to 3, 25, and 50 km from the emission source in the prevailing wind direction. The data on the amount of bacterial and fungal biomass provided evidence of the profound degradation of the soils in the heavily polluted zone. In particular, the biomass of the soil microbiota, including its prokaryotic and eukaryotic components, was two to six times lower in this zone than in the background (control) area. The soils of the heavily polluted zone can be classified as strongly toxic for plants, and most of the soils of the moderately polluted zone also fall into the same category.

  11. Separation behavior of impurities and selenium reduction by the reactive zone refining process using high-frequency induction heating to purify Te

    NASA Astrophysics Data System (ADS)

    Shim, Moonsoo; Kim, Young-Min; Lee, Huk-Hee; Hong, Soon-Jik; Lee, Jong-Hyeon

    2016-12-01

    A zone refining processing was utilized to purify tellurium (Te) metal using a locally melted zone caused by high-frequency induction heating. The travel rate of the molten zone was set as a parameter. The purification efficiency for each impurity (Bi, Sb, Sn, and Se) in the tellurium sample was analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES), and the experimental results were compared with the theoretical results furnished by the proposed model to validate its predictions. The experimental results indicated that a lower travel rate of the molten zone and repetition of passes were more efficient for purification. The effective distribution coefficient keff and the keff values of bismuth, antimony, tin, and selenium were 0.5, 0.35, 0.22, and 0.58, respectively. These elements were effective for the purification of Te by zone refining. The obtained distribution coefficient keff values of impurities can be used as standards for the purification of Te by zone refining. The Vickers hardness was measured, and a correlation between hardness and concentration was observed, with an average Vickers hardness was 62 Hv.

  12. Promoting Protection Against a Threat That Evokes Positive Affect: The Case of Heat Waves in the United Kingdom

    PubMed Central

    2016-01-01

    Heat waves can cause death, illness, and discomfort, and are expected to become more frequent as a result of climate change. Yet, United Kingdom residents have positive feelings about hot summers that may undermine their willingness to protect themselves against heat. We randomly assigned United Kingdom participants to 1 of 3 intervention strategies intended to promote heat protection, or to a control group. The first strategy aimed to build on the availability heuristic by asking participants to remember high summer temperatures, but it elicited thoughts of pleasantly hot summer weather. The second strategy aimed to build on the affect heuristic by evoking negative affect about summer temperatures, but it evoked thoughts of unpleasantly cold summer weather. The third strategy combined these 2 approaches and succeeded in evoking thoughts of unpleasantly hot summer weather. Across 2 experiments, the third (combined) strategy increased participants’ expressed intentions to protect against heat compared with the control group, while performing at least as well as the 2 component strategies. We discuss implications for developing interventions about other “pleasant hazards.” PMID:27268282

  13. Simulated heat waves affected alpine grassland only in combination with drought

    NASA Astrophysics Data System (ADS)

    De Boeck, Hans J.; Bassin, Seraina; Verlinden, Maya; Zeiter, Michaela; Hiltbrunner, Erika

    2016-04-01

    The Alpine region is warming fast, leading to an increase in the frequency and intensity of climate extremes. Currently, it is unclear whether alpine ecosystems are sensitive or resistant to such extremes. In an experiment carried out in the Swiss Alps, we subjected Swiss alpine grassland communities to heat waves with varying intensity (5-10 °C warming) by transplanting monoliths to four different elevations (2440-660 m a.s.l.) for 17 days. Half of the monoliths were regularly irrigated while the other half were deprived of irrigation to additionally induce a drought at each site. We found that heat waves had no significant short-term impacts on fluorescence (Fv/Fm, a stress indicator), senescence and aboveground productivity if irrigation was provided. However, when heat waves coincided with drought, plants showed clear signs of stress, resulting in vegetation browning and reduced phytomass production. This likely resulted from direct drought effects, but also, as measurements of stomatal conductance and canopy temperatures suggest, from increased high-temperature stress as water scarcity decreased heat mitigation through transpiration. The immediate responses to heat waves (with or without droughts) recorded in these alpine grasslands were similar to those observed in the more extensively studied grasslands from temperate climates. Climate extreme impacts may differ in the longer run, however, because the short growing season in alpine environments likely constrains recovery.

  14. An examination of factors affecting radio frequency heating of an encased meat emulsion.

    PubMed

    Lyng, James G; Cronin, Denis A; Brunton, Nigel P; Li, Wenqu; Gu, Xiaohong

    2007-03-01

    The potential of radiofrequency (RF) heating for rapid cooking of a cased comminuted meat emulsion (white pudding) to a pasteurisation temperature of 73°C was examined. Immersion of the product in water was essential in order to prevent thermal damage to the casings by electrical arcing effects during heating. Using a polyethylene heating cell with non-circulating water the applied RF power, primary electrode distance as well as the mineral content, temperature and volume of the surrounding water all influenced the efficiency of the RF heating. Under optimised conditions maximum/minimum temperature gradients (ΔT) across the products in excess of 15°C were observed. These could be reduced to around 6°C by heating the white puddings in a cell operating with recirculating hot water (80°C). Using an oven power output of 450W a 4.3-fold reduction in cooking time compared to conventional steam oven cooking could be achieved.

  15. Probability of US Heat Waves Affected by a Subseasonal Planetary Wave Pattern

    NASA Technical Reports Server (NTRS)

    Teng, Haiyan; Branstator, Grant; Wang, Hailan; Meehl, Gerald A.; Washington, Warren M.

    2013-01-01

    Heat waves are thought to result from subseasonal atmospheric variability. Atmospheric phenomena driven by tropical convection, such as the Asian monsoon, have been considered potential sources of predictability on subseasonal timescales. Mid-latitude atmospheric dynamics have been considered too chaotic to allow significant prediction skill of lead times beyond the typical 10-day range of weather forecasts. Here we use a 12,000-year integration of an atmospheric general circulation model to identify a pattern of subseasonal atmospheric variability that can help improve forecast skill for heat waves in the United States. We find that heat waves tend to be preceded by 15-20 days by a pattern of anomalous atmospheric planetary waves with a wavenumber of 5. This circulation pattern can arise as a result of internal atmospheric dynamics and is not necessarily linked to tropical heating.We conclude that some mid-latitude circulation anomalies that increase the probability of heat waves are predictable beyond the typical weather forecast range.

  16. Simulated heat waves affected alpine grassland only in combination with drought.

    PubMed

    De Boeck, Hans J; Bassin, Seraina; Verlinden, Maya; Zeiter, Michaela; Hiltbrunner, Erika

    2016-01-01

    The Alpine region is warming fast, and concurrently, the frequency and intensity of climate extremes are increasing. It is currently unclear whether alpine ecosystems are sensitive or resistant to such extremes. We subjected Swiss alpine grassland communities to heat waves with varying intensity by transplanting monoliths to four different elevations (2440-660 m above sea level) for 17 d. Half of these were regularly irrigated while the other half were deprived of irrigation to additionally induce a drought at each site. Heat waves had no significant impacts on fluorescence (Fv /Fm , a stress indicator), senescence and aboveground productivity if irrigation was provided. However, when heat waves coincided with drought, the plants showed clear signs of stress, resulting in vegetation browning and reduced phytomass production. This likely resulted from direct drought effects, but also, as measurements of stomatal conductance and canopy temperatures suggest, from increased high-temperature stress as water scarcity decreased heat mitigation through transpiration. The immediate responses to heat waves (with or without droughts) recorded in these alpine grasslands were similar to those observed in the more extensively studied grasslands from temperate climates. Responses following climate extremes may differ in alpine environments, however, because the short growing season likely constrains recovery.

  17. Fault zone architecture of the San Jacinto fault zone in Horse Canyon, southern California: A model for focused post-seismic fluid flow and heat transfer in the shallow crust

    NASA Astrophysics Data System (ADS)

    Morton, Nissa; Girty, Gary H.; Rockwell, Thomas K.

    2012-05-01

    We report results of a new study of the architecture of the San Jacinto fault zone in Horse Canyon, California, where stream incision has exposed a nearly continuous outcrop of the fault zone at ~ 0.4 km depth. The fault zone at this location consists of a fault core, transition zone, damage zone, and tonalitic wall rocks. We collected and analyzed samples for their bulk and grain density, geochemical data, clay mineralogy, and textural and modal mineralogy. Progressive deformation within the fault zone is characterized by mode I cracking, subsequent shearing of already fractured rock, and cataclastic flow. Grain comminution advances towards the strongly indurated cataclasite fault core. Damage progression towards the core is accompanied by a decrease in bulk and grain density, and an increase in porosity and dilational volumetric strain. Palygorskite and mixed-layer illite/smectite clay minerals are present in the damage and transition zones and are the result of hydrolysis reactions. The estimated percentage of illite in illite/smectite increases towards the fault core where the illite/smectite to illite conversion is complete, suggesting elevated temperatures that may have reached 150 °C. Chemical alteration and elemental mass changes are observed throughout the fault zone and are most pronounced in the fault core. We conclude that the observed chemical and mineralogical changes can only be produced by the interaction of fractured wall rocks and chemically active fluids that are mobilized through the fault zone by thermo-pressurization during and after seismic events. Based on the high element mobility and absence of illite/smectite in the fault core, we expect that the greatest water/rock ratios occur within the fault core. These results indicate that hot pore fluids circulate upwards through the fractured fault core and into the surrounding damage zone. Though difficult to constrain, we speculate that the site studied during this investigation may represent

  18. Heat and moisture production of growing-finishing gilts as affected by environmental temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat and moisture production (HMP) values are used to size ventilation fans in animal housing. The HMP values that are currently published in the ASABE (American Society of Agricultural and Biological Engineers) standards were from data collected in the early 1950. This study is one of a series of...

  19. Drought and Heat Differentially Affect XTH Expression and XET Activity and Action in 3-Day-Old Seedlings of Durum Wheat Cultivars with Different Stress Susceptibility

    PubMed Central

    Iurlaro, Andrea; De Caroli, Monica; Sabella, Erika; De Pascali, Mariarosaria; Rampino, Patrizia; De Bellis, Luigi; Perrotta, Carla; Dalessandro, Giuseppe; Piro, Gabriella; Fry, Stephen C.; Lenucci, Marcello S.

    2016-01-01

    Heat and drought stress have emerged as major constraints for durum wheat production. In the Mediterranean area, their negative effect on crop productivity is expected to be exacerbated by the occurring climate change. Xyloglucan endotransglucosylase/hydrolases (XTHs) are chief enzymes in cell wall remodeling, whose relevance in cell expansion and morphogenesis suggests a central role in stress responses. In this work the potential role of XTHs in abiotic stress tolerance was investigated in durum wheat. The separate effects of dehydration and heat exposure on XTH expression and its endotransglucosylase (XET) in vitro activity and in vivo action have been monitored, up to 24 h, in the apical and sub-apical root regions and shoots excised from 3-day-old seedlings of durum wheat cultivars differing in stress susceptibility/tolerance. Dehydration and heat stress differentially influence the XTH expression profiles and the activity and action of XET in the wheat seedlings, depending on the degree of susceptibility/tolerance of the cultivars, the organ, the topological region of the root and, within the root, on the gradient of cell differentiation. The root apical region was the zone mainly affected by both treatments in all assayed cultivars, while no change in XET activity was observed at shoot level, irrespective of susceptibility/tolerance, confirming the pivotal role of the root in stress perception, signaling, and response. Conflicting effects were observed depending on stress type: dehydration evoked an overall increase, at least in the apical region of the root, of XET activity and action, while a significant inhibition was caused by heat treatment in most cultivars. The data suggest that differential changes in XET action in defined portions of the root of young durum wheat seedlings may have a role as a response to drought and heat stress, thus contributing to seedling survival and crop establishment. A thorough understanding of the mechanisms underlying

  20. Heat exposure of Cannabis sativa extracts affects the pharmacokinetic and metabolic profile in healthy male subjects.

    PubMed

    Eichler, Martin; Spinedi, Luca; Unfer-Grauwiler, Sandra; Bodmer, Michael; Surber, Christian; Luedi, Markus; Drewe, Juergen

    2012-05-01

    The most important psychoactive constituent of CANNABIS SATIVA L. is Δ (9)-tetrahydrocannabinol (THC). Cannabidiol (CBD), another important constituent, is able to modulate the distinct unwanted psychotropic effect of THC. In natural plant extracts of C. SATIVA, large amounts of THC and CBD appear in the form of THCA-A (THC-acid-A) and CBDA (cannabidiolic acid), which can be transformed to THC and CBD by heating. Previous reports of medicinal use of cannabis or cannabis preparations with higher CBD/THC ratios and use in its natural, unheated form have demonstrated that pharmacological effects were often accompanied with a lower rate of adverse effects. Therefore, in the present study, the pharmacokinetics and metabolic profiles of two different C. SATIVA extracts (heated and unheated) with a CBD/THC ratio > 1 were compared to synthetic THC (dronabinol) in a double-blind, randomized, single center, three-period cross-over study involving 9 healthy male volunteers. The pharmacokinetics of the cannabinoids was highly variable. The metabolic pattern was significantly different after administration of the different forms: the heated extract showed a lower median THC plasma AUC (24 h) than the unheated extract of 2.84 vs. 6.59 pmol h/mL, respectively. The later was slightly higher than that of dronabinol (4.58 pmol h/mL). On the other hand, the median sum of the metabolites (THC, 11-OH-THC, THC-COOH, CBN) plasma AUC (24 h) was higher for the heated than for the unheated extract. The median CBD plasma AUC (24 h) was almost 2-fold higher for the unheated than for the heated extract. These results indicate that use of unheated extracts may lead to a beneficial change in metabolic pattern and possibly better tolerability.

  1. Concentration of plasticizers applied during heat-moisture treatment affects properties of the modified canna starch.

    PubMed

    Juansang, Juraluck; Puncha-Arnon, Santhanee; Uttapap, Dudsadee; Puttanlek, Chureerat; Rungsardthong, Vilai; Watcharatewinkul, Yanika

    2017-04-15

    Effects of the concentration of plasticizers applied during heat-moisture treatment (HMT) on the properties of canna starch were investigated. The modified starches were prepared by soaking starch in 0 (water), 1, 3, 5, 10, 20 and 30% w/w glycerol or sorbitol solution for 24h and adjusting the moisture content to 25% before HMT (100°C, 1h). Changes in the pasting profiles of heat-moisture treated starches were more obvious when glycerol solutions were used instead of water. An increase in the concentration of glycerol solution from 1% to 5% resulted in a progressive decrease in paste viscosity; paste viscosity then increased as the glycerol concentration rose from 10 to 30%. A similar trend was observed when sorbitol was used as a plasticizer, but with a lesser effect. A scheme for arrangements of the molecular structure of starch during the process of HMT was suggested.

  2. Isoflavone profile in soymilk as affected by soybean variety, grinding, and heat-processing methods.

    PubMed

    Zhang, Yan; Chang, Sam K C; Liu, Zhisheng

    2015-05-01

    Isoflavones impart health benefits and their overall content and profile in foods are greatly influenced at each step during processing. In this study, 2 soybean varieties (Prosoy and black soybean) were processed with 3 different grinding (ambient, cold, and hot grinding) and heating methods (traditional stove cooking, 1-phase UHT, and 2-phase UHT) for soymilk making. The results showed after cold, ambient, and hot grinding, the total isoflavones were 3917, 5013, and 5949 nmol/g for Prosoy; the total isoflavones were 4073, 3966, and 4284 nmol/g for black soybean. Grinding could significantly increase isoflavone extraction. The grinding process had a destructive effect on isoflavones and this effect varied with grinding temperature. Different heating methods had different effects on different isoflavone forms. Two soybean varieties showed distinct patterns with respect to the change of isoflavone profile during processing.

  3. Blocking the beta-adrenergic system does not affect sweat gland function during heat acclimation.

    PubMed

    Martinez, Ricardo; Jones, Douglas; Hodge, Daniel; Buono, Michael J

    2012-08-16

    The purpose of the current study was to test the hypothesis that the beta-adrenergic innervation of the human eccrine sweat gland facilitates greater sweat production following heat acclimation. Eight healthy subjects (mean ± SD age: 25.1 ± 4.1 years, weight: 79.0 ± 16.1 kg, and VO(2)max: 48.5 ± 8.0 ml/kg/min) underwent active heat acclimation by walking at 40% of their VO(2)max for 8 days (90 min a day) in an environmental chamber (35.3 ± 0.8°C and 40.2 ± 2.1% rH). To test the hypothesis, the adrenergic component of sweat gland innervation was inhibited by continuously administering a 0.5% solution of the beta-adrenergic antagonist propranolol via iontophoresis to a 5 cm(2) area of one forearm during each 90-min exercise bout. The opposing control forearm underwent iontophoresis with a saline solution. Following heat acclimation, mean sweat rate in the inhibited and control forearm was 0.47 ± 0.30 mg/cm(2)/min and 0.44 ± 0.25mg/cm(2)/min, respectively. Findings of the current study fail to support the hypothesis that adrenergic innervation facilitates human eccrine sweat gland function during heat acclimation, as no significant differences in sweating were observed. In light of the above, the physiological significance of the dual cholinergic and adrenergic innervation of the eccrine sweat gland has yet to be determined.

  4. Factors affecting projected Arctic surface shortwave heating and albedo change in coupled climate models.

    PubMed

    Holland, Marika M; Landrum, Laura

    2015-07-13

    We use a large ensemble of simulations from the Community Earth System Model to quantify simulated changes in the twentieth and twenty-first century Arctic surface shortwave heating associated with changing incoming solar radiation and changing ice conditions. For increases in shortwave absorption associated with albedo reductions, the relative influence of changing sea ice surface properties and changing sea ice areal coverage is assessed. Changes in the surface sea ice properties are associated with an earlier melt season onset, a longer snow-free season and enhanced surface ponding. Because many of these changes occur during peak solar insolation, they have a considerable influence on Arctic surface shortwave heating that is comparable to the influence of ice area loss in the early twenty-first century. As ice area loss continues through the twenty-first century, it overwhelms the influence of changes in the sea ice surface state, and is responsible for a majority of the net shortwave increases by the mid-twenty-first century. A comparison with the Arctic surface albedo and shortwave heating in CMIP5 models indicates a large spread in projected twenty-first century change. This is in part related to different ice loss rates among the models and different representations of the late twentieth century ice albedo and associated sea ice surface state.

  5. Factors affecting projected Arctic surface shortwave heating and albedo change in coupled climate models

    PubMed Central

    Holland, Marika M.; Landrum, Laura

    2015-01-01

    We use a large ensemble of simulations from the Community Earth System Model to quantify simulated changes in the twentieth and twenty-first century Arctic surface shortwave heating associated with changing incoming solar radiation and changing ice conditions. For increases in shortwave absorption associated with albedo reductions, the relative influence of changing sea ice surface properties and changing sea ice areal coverage is assessed. Changes in the surface sea ice properties are associated with an earlier melt season onset, a longer snow-free season and enhanced surface ponding. Because many of these changes occur during peak solar insolation, they have a considerable influence on Arctic surface shortwave heating that is comparable to the influence of ice area loss in the early twenty-first century. As ice area loss continues through the twenty-first century, it overwhelms the influence of changes in the sea ice surface state, and is responsible for a majority of the net shortwave increases by the mid-twenty-first century. A comparison with the Arctic surface albedo and shortwave heating in CMIP5 models indicates a large spread in projected twenty-first century change. This is in part related to different ice loss rates among the models and different representations of the late twentieth century ice albedo and associated sea ice surface state. PMID:26032318

  6. Aggregate-cement paste transition zone properties affecting the salt-frost damage of high-performance concretes

    SciTech Connect

    Cwirzen, Andrzej; Penttala, Vesa

    2005-04-01

    The influence of the cement paste-aggregate interfacial transition zone (ITZ) on the frost durability of high-performance silica fume concrete (HPSFC) has been studied. Investigation was carried out on eight non-air-entrained concretes having water-to-binder (W/B) ratios of 0.3, 0.35 and 0.42 and different additions of condensed silica fume. Studies on the microstructure and composition of the cement paste have been made by means of environmental scanning electron microscope (ESEM)-BSE, ESEM-EDX and mercury intrusion porosimetry (MIP) analysis. The results showed that the transition zone initiates and accelerates damaging mechanisms by enhancing movement of the pore solution within the concrete during freezing and thawing cycles. Cracks filled with ettringite were primarily formed in the ITZ. The test concretes having good frost-deicing salt durability featured a narrow transition zone and a decreased Ca/Si atomic ratio in the transition zone compared to the bulk cement paste. Moderate additions of silica fume seemed to densify the microstructure of the ITZ.

  7. Pre-operative variables affecting final vision outcome with a critical review of ocular trauma classification for posterior open globe (zone III) injury

    PubMed Central

    Agrawal, Rupesh; Ho, Sue Wei; Teoh, Stephen

    2013-01-01

    Purpose: To identify pre-operative variables affecting the outcome of posterior open globe (zone III) injuries. Secondary objective was to re-look at the definition or landmarks for zone III injury and its clinical significance for predicting visual prognosis following open globe injury. Materials and Methods: Retrospective review of medical records of all hospitalized patients with surgical repair of open globe injury over last 10 years at a tertiary referral eye care center in Singapore. Out of 172 eyes with open globe injury, 28 eyes (16.3%) with zone III injury was identified and reviewed further. Pre-operative visual acuity (VA) and other variables, extent of scleral wound in reference to rectus insertion, relative afferent pupillary defect (RAPD) and final vision outcome were recorded. Results: Median age was 37 years with male predilection (92.9%). Mean follow-up was 12.9 months. Pre-operative VA was no light perception (NLP) in 16 (57.1%) eyes. Final VA remained NLP in 14 eyes (50.0%). The factors contributing to poor post-operative vision based on univariate regression analysis were the presence of RAPD, poor pre-operative VA, blunt trauma, extent of trauma, associated traumatic cataract, hyphema, vitreous loss and associated vitreo-retinal trauma. Further on, zone III injuries with scleral wound limited anterior to rectus insertion (6 eyes) had better vision outcome than those with injuries extending beyond rectus insertion (22 eyes). Conclusion: Initial VA, blunt ocular trauma, visual axis involvement, loss of light perception, presence of RAPD, traumatic cataract, hyphema, vitreous loss were the important determinants for final visual outcome in patients with zone III injury. Wound extending posterior to rectus insertion has poorer outcome as those limited anterior to rectus insertion. We suggest that there may be a need to relook at zone III injuries with reference to rectus insertion for prognostic significance, and further studies are warranted. PMID

  8. Temperature change affected groundwater quality in a confined marine aquifer during long-term heating and cooling.

    PubMed

    Saito, Takeshi; Hamamoto, Shoichiro; Ueki, Takashi; Ohkubo, Satoshi; Moldrup, Per; Kawamoto, Ken; Komatsu, Toshiko

    2016-05-01

    Global warming and urbanization together with development of subsurface infrastructures (e.g. subways, shopping complexes, sewage systems, and Ground Source Heat Pump (GSHP) systems) will likely cause a rapid increase in the temperature of relatively shallow groundwater reservoirs (subsurface thermal pollution). However, potential effects of a subsurface temperature change on groundwater quality due to changed physical, chemical, and microbial processes have received little attention. We therefore investigated changes in 34 groundwater quality parameters during a 13-month enhanced-heating period, followed by 14 months of natural or enhanced cooling in a confined marine aquifer at around 17 m depth on the Saitama University campus, Japan. A full-scale GSHP test facility consisting of a 50 m deep U-tube for circulating the heat-carrying fluid and four monitoring wells at 1, 2, 5, and 10 m from the U-tube were installed, and groundwater quality was monitored every 1-2 weeks. Rapid changes in the groundwater level in the area, especially during the summer, prevented accurate analyses of temperature effects using a single-well time series. Instead, Dual-Well Analysis (DWA) was applied, comparing variations in subsurface temperature and groundwater chemical concentrations between the thermally-disturbed well and a non-affected reference well. Using the 1 m distant well (temperature increase up to 7 °C) and the 10 m distant well (non-temperature-affected), the DWA showed an approximately linear relationships for eight components (B, Si, Li, dissolved organic carbon (DOC), Mg(2+), NH4(+), Na(+), and K(+)) during the combined 27 months of heating and cooling, suggesting changes in concentration between 4% and 31% for a temperature change of 7 °C.

  9. Heat generation during ultrasonic instrumentation of dentin as affected by different irrigation methods.

    PubMed

    Nicoll, B K; Peters, R J

    1998-08-01

    Heat is produced by magnetostrictive ultrasonic scalers which may cause injury to pulpal and periodontal tissues. Water coolant flows around the instrument stack and is directed at the instrument tip to reduce the generation of heat. Sound surgical practice requires the use of a sterile coolant for ultrasonic scaling during surgery. Intermittent bulb irrigation is one way to deliver sterile coolant when using ultrasonic scalers not equipped with a dedicated sterile water reservoir. The purpose of this study was to compare the temperature rise in dentin during ultrasonic scaling using either ultrasonic handpiece irrigation or intermittent bulb irrigation. Twenty dentin/cementum root slabs were prepared for each thickness of 0.5, 1.5, and 2.5 mm. A 3.0 mm x 1.5 mm field was outlined on each slab to indicate the area of intended instrumentation. Each slab was mounted such that a thermocouple placed in contact with dentin opposite the area of instrumentation was shielded from irrigation. Twenty samples of each thickness were ultrasonically scaled during which dentin temperature was recorded every 5 seconds over a 30-second period. All 60 slabs were first treated with dental unit ultrasonic handpiece water irrigation, followed by no irrigation, and finally by bulb irrigation with sterile saline. Repeated measures analysis of variance indicated that there were differences among the three treatment groups for temperature change over the course of the study (P < 0.001). Dentin temperature increased with both decreasing slab thickness and with increasing duration of instrumentation. However, only scaling without irrigation produced a rise in dentin temperature from baseline to a level reported as deleterious to pulpal and periodontal tissues. Bulb syringe irrigation delivered as a continuous drip and ultrasonic unit water spray minimized heat generation to physiologically tolerable levels. Intermittent bulb irrigation appears to be a satisfactory alternative to use of

  10. Water Deficit and Heat Affect the Tolerance to High Illumination in Hibiscus Plants

    PubMed Central

    Muñoz, Romualdo; Quiles, María José

    2013-01-01

    This work studies the effects of water deficit and heat, as well as the involvement of chlororespiration and the ferredoxin-mediated cyclic pathway, on the tolerance of photosynthesis to high light intensity in Hibiscus rosa-sinensis plants. Drought and heat resulted in the down–regulation of photosynthetic linear electron transport in the leaves, although only a slight decrease in variable fluorescence (Fv)/maximal fluorescence (Fm) was observed, indicating that the chloroplast was protected by mechanisms that dissipate excess excitation energy to prevent damage to the photosynthetic apparatus. The incubation of leaves from unstressed plants under high light intensity resulted in an increase of the activity of electron donation by nicotinamide adenine dinucleotide phosphate (NADPH) and ferredoxin to plastoquinone, but no increase was observed in plants exposed to water deficit, suggesting that cyclic electron transport was stimulated by high light only in control plants. In contrast, the activities of the chlororespiration enzymes (NADH dehydrogenase (NDH) complex and plastid terminal oxidase (PTOX)) increased after incubation under high light intensity in leaves of the water deficit plants, but not in control plants, suggesting that chlororespiration was stimulated in stressed plants. The results indicate that the relative importance of chlororespiration and the cyclic electron pathway in the tolerance of photosynthesis to high illumination differs under stress conditions. When plants were not subjected to stress, the contribution of chlororespiration to photosynthetic electron flow regulation was not relevant, and another pathway, such as the ferredoxin-mediated cyclic pathway, was more important. However, when plants were subjected to water deficit and heat, chlororespiration was probably essential. PMID:23470922

  11. Heating and reduction affect the reaction with tannins of wine protein fractions differing in hydrophobicity.

    PubMed

    Marangon, Matteo; Vincenzi, Simone; Lucchetta, Marco; Curioni, Andrea

    2010-02-15

    During the storage, bottled white wines can manifest haziness due to the insolubilisation of the grape proteins that may 'survive' in the fermentation process. Although the exact mechanism of this occurrence is not fully understood, proteins and tannins are considered two of the key factors involved in wine hazing, since their aggregation leads to the formation of insoluble particles. To better understand this complex interaction, proteins and tannins from the same unfined Pinot grigio wine were separated. Wine proteins were then fractionated by hydrophobic interaction chromatography (HIC). A significant correlation between hydrophobicity of the wine protein fractions and the haze formed after reacting with wine tannins was found, with the most reactive fractions revealing (by SDS-PAGE and RP-HPLC analyses) the predominant presence of thaumatin-like proteins. Moreover, the effects of both protein heating and disulfide bonds reduction (with dithiotreithol) on haze formation in the presence of tannins were assessed. These treatments generally resulted in an improved reactivity with tannins, and this phenomenon was related to both the surface hydrophobicity and composition of the protein fractions. Therefore, haze formation in wines seems to be related to hydrophobic interactions occurring among proteins and tannins. These interactions should occur on hydrophobic tannin-binding sites, whose exposition on the proteins can depend on both protein heating and reduction.

  12. Evaluation of factors affecting soil carbon sequestration services of stormwater wet retention ponds in varying climate zones.

    PubMed

    Merriman, L S; Moore, T L C; Wang, J W; Osmond, D L; Al-Rubaei, A M; Smolek, A P; Blecken, G T; Viklander, M; Hunt, W F

    2017-04-01

    The carbon sequestration services of stormwater wet retention ponds were investigated in four different climates: U.S., Northern Sweden, Southern Sweden, and Singapore, representing a range of annual mean temperatures, growing season lengths and rainfall depths: geographic factors that were not statistically compared, but have great effect on carbon (C) accumulation. A chronosequence was used to estimate C accumulations rates; C accumulation and decomposition rates were not directly measured. C accumulated significantly over time in vegetated shallow water areas (0-30cm) in the USA (78.4gCm(-2)yr(-1)), in vegetated temporary inundation zones in Sweden (75.8gCm(-2)yr(-1)), and in all ponds in Singapore (135gCm(-2)yr(-1)). Vegetative production appeared to exert a stronger influence on relative C accumulation rates than decomposition. Comparing among the four climatic zones, the effects of increasing rainfall and growing season lengths (vegetative production) outweighed the effects of higher temperature on decomposition rates. Littoral vegetation was a significant source to the soil C pool relative to C sources draining from watersheds. Establishment of vegetation in the shallow water zones of retention ponds is vital to providing a C source to the soil. Thus, the width of littoral shelves containing this vegetation along the perimeter may be increased if C sequestration is a design goal. This assessment establishes that stormwater wet retention ponds can sequester C across different climate zones with generally annual rainfall and lengths of growing season being important general factors for C accumulation.

  13. A Physical Metallurgical Basis for Heat-Affected Zone and Base-Plate Properties of a Microalloyed HSLA Steel.

    DTIC Science & Technology

    1986-12-01

    Allen, W. P. Rees, B. E. Hopkins, H. R. Tipler , "Tensile and Impact Properties of Iron-Carbon and Iron-Carbon-Manganese alloys of Low Carbon Content...0 mc (3 *93a3) 3unIVU3dW𔃽 0 0 (0 co 0GJ LOI 4jU C L0 oZ 0 x 03 w 0Y (0~~~~~~ [I ( ~l.~d~3 346 T-313 6 0 o 1u 1A 00 (D 0 Se, (00 CJ S ’ 41 C uJ 0 0~ 2

  14. Microstructure characterization and weldability evaluation of the weld heat affected zone (HAZ) in 310HCbN tubing

    SciTech Connect

    Lundin, C.D.; Qiao, C.Y.P.

    1995-08-01

    Metallographic evaluation on the Gleeble simulated HAZ samples of 310HCbN tubing material was performed in order to reveal potential degradation in mechanical properties and corrosion resistance. The carbide evolutionary process in the HAZ samples was studied. It is indicated that 310HCbN material showed a weld HAZ sensitization tendency that is associated with the formation of Cr{sub 23}C{sub 6}.

  15. A Correlation Between the Heat Affected Zone Microstructure and the Thermal History During Welding of HY-130 Steel.

    DTIC Science & Technology

    1981-09-01

    the weld. Additionally, Lipsey [Ref. 9] used a computer program to predict the temperature at various 11 locations in the test plate. in all of these...M.I.T. OSP#82558, November 1980. 7. Rogalski, W. J., "An Economic and Technical Study on the Feasibility of Using Advanced Joining Techniques in... Lipsey , M. D., "Investigation of Welding Thermal Strains in High Strength Quenched and Tempered Steel," Ocean Engineer Thesis, Massachusetts Institute

  16. High hydrogen peroxide concentration in the feed-zone affects bioreactor cell productivity with liquid phase oxygen supply strategy.

    PubMed

    Sarkar, Pritish; Ghosh, Kaushik; Suraishkumar, G K

    2008-06-01

    Liquid phase oxygen supply strategy (LPOS), in which hydrogen peroxide (H(2)O(2)) is used to supply oxygen to the bioreactor, leads to low cell productivity despite high specific productivities of relevant metabolites. We hypothesized that high H(2)O(2) concentrations in the feed-zone led to local cell death, which in turn, lead to lower cell productivity. To test the hypothesis, a mathematical model was developed. Bacillus subtilis 168 was used as the model system in this study. The model simulations of cell concentrations in the bioreactor-zone were verified with the experimental results. The feed-zone H(2)O(2) concentrations remained 12-14 times higher than bulk bioreactor concentrations. The high local concentrations are expected to cause local cell killing, which explains the decrease in overall cell production by 50% at 300 rpm compared to conventional cultivation. Further, among the four different feed strategies studied using the model, dissolved oxygen (DO) controlled H(2)O(2) feed strategy caused least local cell killing and improved overall cell production by 34%.

  17. Tomato growth as affected by root-zone temperature and the addition of gibberellic acid and kinetin to nutrient solutions

    NASA Technical Reports Server (NTRS)

    Bugbee, B.; White, J. W.; Salisbury, F. B. (Principal Investigator)

    1984-01-01

    The effect of root-zone temperature on young tomato plants (Lycopersicon esculentum Mill. cv. Heinz 1350) was evaluated in controlled environments using a recirculating solution culture system. Growth rates were measured at root-zone temperatures of 15 degrees, 20 degrees, 25 degrees, and 30 degrees C in a near optimum foliar environment. Optimum growth occurred at 25 degrees to 30 degrees during the first 4 weeks of growth and 20 degrees to 25 degrees during the 5th and 6th weeks. Growth was severely restricted at 15 degrees. Four concentrations of gibberellic acid (GA3) and kinetin were added to the nutrient solution in a separate trial; root-zone temperature was maintained at 15 degrees and 25 degrees. Addition of 15 micromoles GA3 to solutions increased specific leaf area, total leaf area, and dry weight production of plants in both temperature treatments. GA3-induced growth stimulation was greater at 15 degrees than at 25 degrees. GA3 may promote growth by increasing leaf area, enhancing photosynthesis per unit leaf area, or both. Kinetic was not useful in promoting growth at either temperature.

  18. Colloid formation and metal transport through two mixing zones affected by acid mine drainage near Silverton, Colorado

    USGS Publications Warehouse

    Schemel, L.E.; Kimball, B.A.; Bencala, K.E.

    2000-01-01

    Stream discharges and concentrations of dissolved and colloidal metals (Al, Ca, Cu, Fe, Mg, Mn, Pb, and Zn), SO4, and dissolved silica were measured to identify chemical transformations and determine mass transports through two mixing zones in the Animas River that receive the inflows from Cement and Mineral Creeks. The creeks were the dominant sources of Al, Cu, Fe, and Pb, whereas the upstream Animas River supplied about half of the Zn. With the exception of Fe, which was present in dissolved and colloidal forms, the metals were dissolved in the acidic, high-SO4 waters of Cement Creek (pH 3.8). Mixing of Cement Creek with the Animas River increased pH to near-neutral values and transformed Al and some additional Fe into colloids which also contained Cu and Pb. Aluminium and Fe colloids had already formed in the mildly acidic conditions in Mineral Creek (pH 6.6) upstream of the confluence with the Animas River. Colloidal Fe continued to form downstream of both mixing zones. The Fe- and Al-rich colloids were important for transport of Cu, Pb, and Zn, which appeared to have sorbed to them. Partitioning of Zn between dissolved and colloidal phases was dependent on pH and colloid concentration. Mass balances showed conservative transports for Ca, Mg, Mn, SO4, and dissolved silica through the two mixing zones and small losses (< 10%) of colloidal Al, Fe and Zn from the water column.

  19. Loop heating by D.C. electric current and electromagnetic wave emissions simulated by 3-D EM particle zone

    NASA Technical Reports Server (NTRS)

    Sakai, J. I.; Zhao, J.; Nishikawa, K.-I.

    1994-01-01

    We have shown that a current-carrying plasma loop can be heated by magnetic pinch driven by the pressure imbalance between inside and outside the loop, using a 3-dimensional electromagnetic (EM) particle code. Both electrons and ions in the loop can be heated in the direction perpendicular to the ambient magnetic field, therefore the perpendicular temperature can be increased about 10 times compared with the parallel temperature. This temperature anisotropy produced by the magnetic pinch heating can induce a plasma instability, by which high-frequency electromagnetic waves can be excited. The plasma current which is enhanced by the magnetic pinch can also excite a kinetic kink instability, which can heat ions perpendicular to the magnetic field. The heating mechanism of ions as well as the electromagnetic emission could be important for an understanding of the coronal loop heating and the electromagnetic wave emissions from active coronal regions.

  20. Gas motion through porous objects with nonuniform local distribution of heat-release sources

    NASA Astrophysics Data System (ADS)

    Levin, V. A.; Lutsenko, N. A.

    2008-09-01

    The gas motion through porous objects in the gravity force field with a non-uniform distribution of heat sources, which may arise as a result of natural or man-caused catastrophes (as the damaged power unit of the Chernobyl NPP), is investigated. The influence of different parameters of the heat-releasing zone on the process of cooling of such objects is analyzed with the aid of computational experiment. It is shown that the porous element heating is affected not only by the height of the heat-releasing zone and the heat-release intensity therein but also by the distance of the heat-releasing zone from the element inlet as well as by the width of the heat-releasing zone. The phenomenon of a reduction of the porous element heating with increasing distance of the heat-releasing zone from the porous element inlet is revealed. An ambiguous dependence of the porous object heating on the width of the heat-release zone is identified: at a growth of the heat-releasing zone width, the heating of the element may both increase and decrease depending on the distance of the heat-release zone from the element inlet.

  1. The impact of fault zones on the 3D coupled fluid and heat transport for the area of Brandenburg (NE German Basin)

    NASA Astrophysics Data System (ADS)

    Yvonne, Cherubini; Mauro, Cacace; Scheck-Wenderoth, Magdalena

    2013-04-01

    Faults can provide permeable pathways for fluids at a variety of scales, from great depth in the crust to flow through fractured aquifers, geothermal fields, and hydrocarbon reservoirs (Barton et al. 1995). In terms of geothermal energy exploration, it is essential to understand the role of faults and their impact on the thermal field and fluid system. 3D numerical simulations provide a useful tool for investigating the active physical processes in the subsurface. To assess the influence of major fault zones on the thermal field and fluid system, 3D coupled fluid and heat transport simulations are carried out. The study is based on a recently published structural model of the Brandenburg area, which is located in the south-eastern part of the Northeast German Basin (NEGB) (Noack et al. 2010). Two major fault zones of the Elbe Fault System (Gardelegen and Lausitz Escarpments) vertically offset the pre-Permian basement against the Permian to Cenozoic basin fill at the southern margin by several km (Scheck et al. 2002). Within the numerical models, these two major fault zones are represented as equivalent porous media and vertical discrete elements. The coupled system of equations describing fluid flow and heat transport in saturated porous media are numerically solved by the Finite Element software FEFLOW® (Diersch, 2002). Different possible geological scenarios are modelled and compared to a simulation in which no faults are considered. In one scenario the fault zones are set as impermeable. In this case, the thermal field is similar to the no fault model. Fluid flow is redirected because the fault zones act as hydraulic barriers that prevent a lateral fluid advection into the fault zones. By contrast, modelled permeable fault zones induce a pronounced thermal signature with distinctly cooler temperatures than in the no fault model. Fluid motion within the fault is initially triggered by advection due to hydraulic head gradients, but may be even enhanced by

  2. Heat Stress Affects Pi-related Genes Expression and Inorganic Phosphate Deposition/Accumulation in Barley

    PubMed Central

    Pacak, Andrzej; Barciszewska-Pacak, Maria; Swida-Barteczka, Aleksandra; Kruszka, Katarzyna; Sega, Pawel; Milanowska, Kaja; Jakobsen, Iver; Jarmolowski, Artur; Szweykowska-Kulinska, Zofia

    2016-01-01

    Phosphorus (P) in plants is taken from soil as an inorganic phosphate (Pi) and is one of the most important macroelements in growth and development. Plants actively react to Pi starvation by the induced expression of Pi transporters, MIR399, MIR827, and miR399 molecular sponge – IPS1 genes and by the decreased expression of the ubiquitin-conjugating enzyme E2 (PHOSPHATE2 – PHO2) and Pi sensing and transport SPX-MFS genes. The PHO2 protein is involved in the degradation of Pi transporters PHT1;1 (from soil to roots) and PHO1 (from roots to shoots). The decreased expression of PHO2 leads to Pi accumulation in shoots. In contrast, the pho1 mutant shows a decreased level of Pi concentration in shoots. Finally, Pi starvation leads to decreased Pi concentration in all plant tissues. Little is known about plant Pi homeostasis in other abiotic stress conditions. We found that, during the first hour of heat stress, Pi accumulated in barley shoots but not in the roots, and transcriptomic data analysis as well as RT-qPCR led us to propose an explanation for this phenomenon. Pi transport inhibition from soil to roots is balanced by lower Pi efflux from roots to shoots directed by the PHO1 transporter. In shoots, the PHO2 mRNA level is decreased, leading to an increased Pi level. We concluded that Pi homeostasis in barley during heat stress is maintained by dynamic changes in Pi-related genes expression. PMID:27446155

  3. Heat Stress Affects Pi-related Genes Expression and Inorganic Phosphate Deposition/Accumulation in Barley.

    PubMed

    Pacak, Andrzej; Barciszewska-Pacak, Maria; Swida-Barteczka, Aleksandra; Kruszka, Katarzyna; Sega, Pawel; Milanowska, Kaja; Jakobsen, Iver; Jarmolowski, Artur; Szweykowska-Kulinska, Zofia

    2016-01-01

    Phosphorus (P) in plants is taken from soil as an inorganic phosphate (Pi) and is one of the most important macroelements in growth and development. Plants actively react to Pi starvation by the induced expression of Pi transporters, MIR399, MIR827, and miR399 molecular sponge - IPS1 genes and by the decreased expression of the ubiquitin-conjugating enzyme E2 (PHOSPHATE2 - PHO2) and Pi sensing and transport SPX-MFS genes. The PHO2 protein is involved in the degradation of Pi transporters PHT1;1 (from soil to roots) and PHO1 (from roots to shoots). The decreased expression of PHO2 leads to Pi accumulation in shoots. In contrast, the pho1 mutant shows a decreased level of Pi concentration in shoots. Finally, Pi starvation leads to decreased Pi concentration in all plant tissues. Little is known about plant Pi homeostasis in other abiotic stress conditions. We found that, during the first hour of heat stress, Pi accumulated in barley shoots but not in the roots, and transcriptomic data analysis as well as RT-qPCR led us to propose an explanation for this phenomenon. Pi transport inhibition from soil to roots is balanced by lower Pi efflux from roots to shoots directed by the PHO1 transporter. In shoots, the PHO2 mRNA level is decreased, leading to an increased Pi level. We concluded that Pi homeostasis in barley during heat stress is maintained by dynamic changes in Pi-related genes expression.

  4. Effects of smoke, heat, darkness and cold stratification on seed germination of 40 species in a cool temperate zone in northern Japan.

    PubMed

    Tsuyuzaki, S; Miyoshi, C

    2009-05-01

    The effects of smoke, heat, darkness and cold stratification on seed germination were examined for 40 species with various life history attributes. These species establish in early successional stages on a volcano and are distributed in cool temperate zones of northern Japan. Smoke decreased seed germination in 11 species and increased it in one species, Leucothoe grayana. Germination of Polygonum longisetum was enhanced by a combination of smoke and cold, and that of Aralia elata by smoke and heat. Heat increased germination for three species and decreased it for one. Cold stratification broke dormancy in seeds of 11 species. Continuous darkness decreased germination of 22 species and did not increase germination for any species, showing that approximately half of the species require light for maximum germination. Although most species are sun plants that establish in early stages of succession and/or in disturbed areas, smoke and heat do not enhance germination of these species after disturbance, even when the disturbance is fire. Germination of slender and/or large seeds tends to be decreased more by smoke, probably because of their larger surface area. Light is more important than smoke and heat for detection of disturbance and for seed germination in this region. However, despite the low fire frequency in the region, germination of a few species was increased by fire-derived stimuli.

  5. Long-Term Acclimation to Different Thermal Regimes Affects Molecular Responses to Heat Stress in a Freshwater Clam Corbicula Fluminea

    PubMed Central

    Falfushynska, Halina I.; Phan, Tuan; Sokolova, Inna M.

    2016-01-01

    Global climate change (GCC) can negatively affect freshwater ecosystems. However, the degree to which freshwater populations can acclimate to long-term warming and the underlying molecular mechanisms are not yet fully understood. We used the cooling water discharge (CWD) area of a power plant as a model for long-term warming. Survival and molecular stress responses (expression of molecular chaperones, antioxidants, bioenergetic and protein synthesis biomarkers) to experimental warming (20–41 °C, +1.5 °C per day) were assessed in invasive clams Corbicula fluminea from two pristine populations and a CWD population. CWD clams had considerably higher (by ~8–12 °C) lethal temperature thresholds than clams from the pristine areas. High thermal tolerance of CWD clams was associated with overexpression of heat shock proteins HSP70, HSP90 and HSP60 and activation of protein synthesis at 38 °C. Heat shock response was prioritized over the oxidative stress response resulting in accumulation of oxidative lesions and ubiquitinated proteins during heat stress in CWD clams. Future studies should determine whether the increase in thermal tolerance in CWD clams are due to genetic adaptation and/or phenotypic plasticity. Overall, our findings indicate that C. fluminea has potential to survive and increase its invasive range during warming such as expected during GCC. PMID:27995990

  6. Long-Term Acclimation to Different Thermal Regimes Affects Molecular Responses to Heat Stress in a Freshwater Clam Corbicula Fluminea

    NASA Astrophysics Data System (ADS)

    Falfushynska, Halina I.; Phan, Tuan; Sokolova, Inna M.

    2016-12-01

    Global climate change (GCC) can negatively affect freshwater ecosystems. However, the degree to which freshwater populations can acclimate to long-term warming and the underlying molecular mechanisms are not yet fully understood. We used the cooling water discharge (CWD) area of a power plant as a model for long-term warming. Survival and molecular stress responses (expression of molecular chaperones, antioxidants, bioenergetic and protein synthesis biomarkers) to experimental warming (20–41 °C, +1.5 °C per day) were assessed in invasive clams Corbicula fluminea from two pristine populations and a CWD population. CWD clams had considerably higher (by ~8–12 °C) lethal temperature thresholds than clams from the pristine areas. High thermal tolerance of CWD clams was associated with overexpression of heat shock proteins HSP70, HSP90 and HSP60 and activation of protein synthesis at 38 °C. Heat shock response was prioritized over the oxidative stress response resulting in accumulation of oxidative lesions and ubiquitinated proteins during heat stress in CWD clams. Future studies should determine whether the increase in thermal tolerance in CWD clams are due to genetic adaptation and/or phenotypic plasticity. Overall, our findings indicate that C. fluminea has potential to survive and increase its invasive range during warming such as expected during GCC.

  7. Providing plastic zone extrusion

    DOEpatents

    Manchiraju, Venkata Kiran; Feng, Zhili; David, Stan A.; Yu, Zhenzhen

    2017-04-11

    Plastic zone extrusion may be provided. First, a compressor may generate frictional heat in stock to place the stock in a plastic zone of the stock. Then, a conveyer may receive the stock in its plastic zone from the compressor and transport the stock in its plastic zone from the compressor. Next, a die may receive the stock in its plastic zone from the conveyer and extrude the stock to form a wire.

  8. Dynamics and controls of urban heat sink and island phenomena in a desert city: Development of a local climate zone scheme using remotely-sensed inputs

    NASA Astrophysics Data System (ADS)

    Nassar, Ahmed K.; Blackburn, G. Alan; Whyatt, J. Duncan

    2016-09-01

    This study aims to determine the dynamics and controls of Surface Urban Heat Sinks (SUHS) and Surface Urban Heat Islands (SUHI) in desert cities, using Dubai as a case study. A Local Climate Zone (LCZ) schema was developed to subdivide the city into different zones based on similarities in land cover and urban geometry. Proximity to the Gulf Coast was also determined for each LCZ. The LCZs were then used to sample seasonal and daily imagery from the MODIS thermal sensor to determine Land Surface Temperature (LST) variations relative to desert sand. Canonical correlation techniques were then applied to determine which factors explained the variability between urban and desert LST. Our results indicate that the daytime SUHS effect is greatest during the summer months (typically ∼3.0 °C) with the strongest cooling effects in open high-rise zones of the city. In contrast, the night-time SUHI effect is greatest during the winter months (typically ∼3.5 °C) with the strongest warming effects in compact mid-rise zones of the city. Proximity to the Arabian Gulf had the largest influence on both SUHS and SUHI phenomena, promoting daytime cooling in the summer months and night-time warming in the winter months. However, other parameters associated with the urban environment such as building height had an influence on daytime cooling, with larger buildings promoting shade and variations in airflow. Likewise, other parameters such as sky view factor contributed to night-time warming, with higher temperatures associated with limited views of the sky.

  9. Avian thermoregulation in the heat: scaling of heat tolerance and evaporative cooling capacity in three southern African arid-zone passerines.

    PubMed

    Whitfield, Maxine C; Smit, Ben; McKechnie, Andrew E; Wolf, Blair O

    2015-06-01

    Many birds can defend body temperature (Tb) far below air temperature (Ta) during acute heat exposure, but relatively little is known about how avian heat tolerance and evaporative cooling capacity varies with body mass (Mb), phylogeny or ecological factors. We determined maximum rates of evaporative heat dissipation and thermal end points (Tb and Ta associated with thermoregulatory failure) in three southern African ploceid passerines, the scaly-feathered weaver (Sporopipes squamifrons, Mb≈10 g), sociable weaver (Philetairus socius, Mb≈25 g) and white-browed sparrow-weaver (Plocepasser mahali, Mb≈40 g). Birds were exposed to a ramped profile of progressively increasing Ta, with continuous monitoring of behaviour and Tb used to identify the onset of severe hyperthermia. The maximum Ta birds tolerated ranged from 48°C to 54°C, and was positively related to Mb. Values of Tb associated with severe heat stress were in the range of 44 to 45°C. Rates of evaporative water loss (EWL) increased rapidly when Ta exceeded Tb, and maximum evaporative heat dissipation was equivalent to 141-222% of metabolic heat production. Fractional increases in EWL between Ta<40°C and the highest Ta reached by each species were 10.8 (S. squamifrons), 18.4 (P. socius) and 16.0 (P. mahali). Resting metabolic rates increased more gradually with Ta than expected, probably reflecting the very low chamber humidity values we maintained. Our data suggest that, within a taxon, larger species can tolerate higher Ta during acute heat stress.

  10. Early-age heat exposure affects skeletal muscle satellite cell proliferation and differentiation in chicks.

    PubMed

    Halevy, O; Krispin, A; Leshem, Y; McMurtry, J P; Yahav, S

    2001-07-01

    Exposure of young chicks to thermal conditioning (TC; i.e., 37 degrees C for 24 h) resulted in significantly improved body and muscle growth at a later age. We hypothesized that TC causes an increase in satellite cell proliferation, necessary for further muscle hypertrophy. An immediate increase was observed in satellite cell DNA synthesis in culture and in vivo in response to TC of 3-day-old chicks to levels that were significantly higher than those of control chicks. This was accompanied by a marked induction of insulin-like growth factor-I (IFG-I), but not hepatocyte growth factor in the breast muscle. No significant difference between treatments in plasma IGF-I levels was observed. A marked elevation in muscle regulatory factors on day 5, followed by a decline in cell proliferation on day 6 together with continuous high levels of IGF-I in the TC chick muscle may indicate accelerated cell differentiation. These data suggest a central role for IGF-I in the immediate stimulation of satellite cell myogenic processes in response to heat exposure.

  11. Attenuation of sensory and affective responses to heat pain: evidence for contralateral mechanisms.

    PubMed

    Gallez, Ariane; Albanese, Marie-Claire; Rainville, Pierre; Duncan, Gary H

    2005-11-01

    Attenuation of responses to repeated sensory events has been thoroughly studied in many modalities; however, attenuation of pain perception has not yet benefitted from such extensive investigation. Described here are two psychophysical studies that examined the effects of repeated exposure to thermal stimuli, assessing potential attenuation of the perception of pain and its possible spatial specificity. Twenty-two subjects were presented thermal stimuli to the volar surface of the right and left forearms. Twelve subjects in study 1 received the same stimuli and conditions on each of five daily experimental sessions, whereas 10 subjects in study 2 received thermal stimuli, which were restricted to one side for four daily sessions and then applied to the other side on the fifth session. Ratings of warmth intensity, pain intensity, and pain unpleasantness were recorded while the subjects performed a thermal sensory discrimination task. Results of study 1 demonstrate that repeated stimulation with noxious heat can lead to long-term attenuation of pain perception; results of study 2 extend these findings of attenuation to both pain intensity and unpleasantness and show that this effect is highly specific to the exposed body side for both aspects of the pain experience. We suggest that the functional plasticity underlying this attenuation effect lies in brain areas with a strong contralateral pattern of pain-related activation.

  12. Anomalous shear band characteristics and extra-deep shock-affected zone in Zr-based bulk metallic glass treated with nanosecond laser peening

    PubMed Central

    Wei, Yanpeng; Xu, Guangyue; Zhang, Kun; Yang, Zhe; Guo, Yacong; Huang, Chenguang; Wei, Bingchen

    2017-01-01

    The effects of nanosecond laser peening on Zr41Ti14Cu12.5Ni10Be22.5 metallic glass were investigated in this study. The peening treatment produced an extra-deep shock-affected zone compared to crystal metal. As opposed to the conventional shear bands, numerous arc shear bands appeared and aggregated in the vertical direction of the laser beam, forming basic units for accommodating plastic deformation. The arc shear bands exhibited short and discrete features near the surface of the material, then grew longer and fewer at deeper peened layer depths, which was closely related to the laser shock wave attenuation. An energy dissipation model was established based on Hugoniot Elastic Limit and shear band characteristics to represent the formation of an extra-deep shock-affected zone. The results presented here suggest that the bulk modification of metallic glass with a considerable affected depth is feasible. Further, they reveal that nanosecond laser peening is promising as an effective approach to tuning shear bands for improved MGs ductility. PMID:28266649

  13. Anomalous shear band characteristics and extra-deep shock-affected zone in Zr-based bulk metallic glass treated with nanosecond laser peening

    NASA Astrophysics Data System (ADS)

    Wei, Yanpeng; Xu, Guangyue; Zhang, Kun; Yang, Zhe; Guo, Yacong; Huang, Chenguang; Wei, Bingchen

    2017-03-01

    The effects of nanosecond laser peening on Zr41Ti14Cu12.5Ni10Be22.5 metallic glass were investigated in this study. The peening treatment produced an extra-deep shock-affected zone compared to crystal metal. As opposed to the conventional shear bands, numerous arc shear bands appeared and aggregated in the vertical direction of the laser beam, forming basic units for accommodating plastic deformation. The arc shear bands exhibited short and discrete features near the surface of the material, then grew longer and fewer at deeper peened layer depths, which was closely related to the laser shock wave attenuation. An energy dissipation model was established based on Hugoniot Elastic Limit and shear band characteristics to represent the formation of an extra-deep shock-affected zone. The results presented here suggest that the bulk modification of metallic glass with a considerable affected depth is feasible. Further, they reveal that nanosecond laser peening is promising as an effective approach to tuning shear bands for improved MGs ductility.

  14. Physical mechanisms of longitudinal vortexes formation, appearance of zones with high heat fluxes and early transition in hypersonic flow over delta wing with blunted leading edges

    NASA Astrophysics Data System (ADS)

    Alexandrov, S. V.; Vaganov, A. V.; Shalaev, V. I.

    2016-10-01

    Processes of vortex structures formation and they interactions with the boundary layer in the hypersonic flow over delta wing with blunted leading edges are analyzed on the base of experimental investigations and numerical solutions of Navier-Stokes equations. Physical mechanisms of longitudinal vortexes formation, appearance of abnormal zones with high heat fluxes and early laminar turbulent transition are studied. These phenomena were observed in many high-speed wind tunnel experiments; however they were understood only using the detailed analysis of numerical modeling results with the high resolution. Presented results allowed explaining experimental phenomena. ANSYS CFX code (the DAFE MIPT license) on the grid with 50 million nodes was used for the numerical modeling. The numerical method was verified by comparison calculated heat flux distributions on the wing surface with experimental data.

  15. Characterization of the Hydrogen Induced Cold Cracking Susceptibility at Simulated Weld Zones in HSLA-100 Steel

    DTIC Science & Technology

    1994-04-01

    hardness as measured from the center of the gauge section for the HSLA-100 heat affected zone. 57 Figure 14a Low magnification scanning electron micrograph...High magnification scanning electron micrograph from Figure 14a showing the size and distribution of the observed microvoids. 58 Figure 15a Low...magnification scanning electron micrograph of the HSLA-100 heat affected zone showing the characteristic ductile behavior observed in the failures

  16. How radiation affects superbubbles: through momentum injection in early phase and photo-heating thereafter

    NASA Astrophysics Data System (ADS)

    Gupta, Siddhartha; Nath, Biman B.; Sharma, Prateek; Shchekinov, Yuri

    2016-11-01

    Energetic winds and radiation from massive star clusters push the surrounding gas and blow superbubbles in the interstellar medium (ISM). Using 1D hydrodynamic simulations, we study the role of radiation in the dynamics of superbubbles driven by a young star cluster of mass 106 M⊙. We have considered a realistic time evolution of the mechanical power as well as radiation power of the star cluster, and detailed heating and cooling processes. We find that the ratio of the radiation pressure on the shell (shocked ISM) to the thermal pressure (˜107 K) of the shocked-wind region is almost independent of the ambient density, and it is greater than unity before ≲1 Myr. We explore the parameter space of density and dust opacity of the ambient medium, and find that the size of the hot gas (˜107 K) cavity is insensitive to the dust opacity [σd ≈ (0.1-1.5) × 10-21 cm2], but the structure of the photoionized (˜104 K) gas depends on it. Most of the radiative losses occur at ˜104 K, with sub-dominant losses at ≲103 K and ˜106-108 K. The superbubbles can retain as high as ˜10 per cent of its input energy, for an ambient density of 103 mH cm-3. We discuss the role of ionization parameter and recombination-averaged density in understanding the dominant feedback mechanism. Finally, we compare our results with the observations of 30 Doradus.

  17. Study of Reservoir Heterogencities and Structural Features Affecting Production in the Shallow Oil Zone, Eastern Elk Hills Area, California

    SciTech Connect

    Janice Gillespie

    2004-11-01

    Late Neogene (Plio-Pleistocene) shallow marine strata of the western Bakersfield Arch and Elk Hills produce hydrocarbons from several different reservoirs. This project focuses on the shallow marine deposits of the Gusher and Calitroleum reservoirs in the Lower Shallow Oil Zone (LSOZ). In the eastern part of the study area on the Bakersfield Arch at North and South Coles Levee field and in two wells in easternmost Elk Hills, the LSOZ reservoirs produce dry (predominantly methane) gas. In structurally higher locations in western Elk Hills, the LSOZ produces oil and associated gas. Gas analyses show that gas from the eastern LSOZ is bacterial and formed in place in the reservoirs, whereas gas associated with oil in the western part of the study area is thermogenic and migrated into the sands from deeper in the basin. Regional mapping shows that the gas-bearing LSOZ sands in the Coles Levee and easternmost Elk Hills area are sourced from the Sierra Nevada to the east whereas the oil-bearing sands in western Elk Hills appear to be sourced from the west. The eastern Elk Hills area occupied the basin depocenter, farthest from either source area. As a result, it collected mainly low-permeability offshore shale deposits. This sand-poor depocenter provides an effective barrier to the updip migration of gases from east to west. The role of small, listric normal faults as migration barriers is more ambiguous. Because our gas analyses show that the gas in the eastern LSOZ reservoirs is bacterial, it likely formed in-place near the reservoirs and did not have to migrate far. Therefore, the gas could have been generated after faulting and accumulated within the fault blocks as localized pools. However, bacterial gas is present in both the eastern AND western parts of Elk Hills in the Dry Gas Zone (DGZ) near the top of the stratigraphic section even though the measured fault displacement is greatest in this zone. Bacterial gas is not present in the west in the deeper LSOZ which

  18. Root zone temperature affects the phytoextraction of Ba, Cl, Sn, Pt, and Rb using potato plants (Solanum tuberosum L. var. Spunta) in the field.

    PubMed

    Baghour, M; Moreno, D A; Víllora, G; Hernández, J; Castilla, N; Romero, L

    2002-01-01

    Three consecutive years of field experiments were conducted to investigate how different root-zone temperatures, manipulated by using different mulches, affect the phytoextraction of Ba, Cl, Sn, Pt and Rb in different organs of potato plants (roots, tubers, stems and leaves). Four different plastic covers were used (T1: transparent polyethylene; T2: white polyethylene; T3: white and black coextruded polyethylene, and T4: black polyethylene), using uncovered plants as control (T0). The different treatments had a significant effect on mean root zone temperatures (T0 = 16 degrees C, T1 = 20 degrees C, T2 = 23 degrees C, T3 = 27 degrees C and T4 = 30 degrees C) and induced a significantly different response in Ba, Cl, Sn, Pt and Rb concentration and accumulation. The T3 treatment gave rise to the greatest phytoextraction of Ba, Pt, Cl and Sn in the roots, leaflets and tubers. In terms of the relative distribution of the phytoaccumulated elements (as percentage of the total within the plant), Pt and Ba accumulated mainly in the roots whereas Rb, Sn and Cl accumulated primarily in tubers, establishing a close relationship between the biomass development of each organ and phytoaccumulation capacity of metals in response to temperature in the root zone.

  19. Distribution of polychlorinated biphenyls in an urban riparian zone affected by wastewater treatment plant effluent and the transfer to terrestrial compartment by invertebrates.

    PubMed

    Yu, Junchao; Wang, Thanh; Han, Shanlong; Wang, Pu; Zhang, Qinghua; Jiang, Guibin

    2013-10-01

    In this study, we investigated the distribution of polychlorinated biphenyls (PCBs) in a riparian zone affected by the effluent from a wastewater treatment plant (WWTP). River water, sediment, aquatic invertebrates and samples from the surrounding terrestrial compartment such as soil, reed plants and several land based invertebrates were collected. A relatively narrow range of δ(13)C values was found among most invertebrates (except butterflies, grasshoppers), indicating a similar energy source. The highest concentration of total PCBs was observed in zooplankton (151.1 ng/g lipid weight), and soil dwelling invertebrates showed higher concentrations than phytophagous insects at the riparian zone. The endobenthic oligochaete Tubifex tubifex (54.28 ng/g lw) might be a useful bioindicator of WWTP derived PCBs contamination. High bioaccumulation factors (BAFs) were observed in collected aquatic invertebrates, although the biota-sediment/soil accumulation factors (BSAF) remained relatively low. Emerging aquatic insects such as chironomids could carry waterborne PCBs to the terrestrial compartment via their lifecycles. The estimated annual flux of PCBs for chironomids ranged from 0.66 to 265 ng⋅m(-2)⋅y(-1). Although a high prevalence of PCB-11 and PCB-28 was found for most aquatic based samples in this riparian zone, the mid-chlorinated congeners (e.g. PCB-153 and PCB-138) became predominant among chironomids and dragonflies as well as soil dwelling invertebrates, which might suggest a selective biodriven transfer of different PCB congeners.

  20. [Heat exchange of the rat in thermoneutral zone temperature and comparison with heat exchange in ambient temperature over and under it].

    PubMed

    Rumiantsev, G V

    2011-08-01

    With the help of thermonetry and general calorimetry body temperature and heat production in ambient temperatures 20 degrees C, 28 degrees C, 33 degrees C were recorded. The experiments showed, that at the temperature 20 degrees C the rectal temperature was changing very little. But in ambient temperature 33 degrees C the rectal temperature was 40.5 +/- 0.1 degrees C.

  1. Aging and aerobic fitness affect the contribution of noradrenergic sympathetic nerves to the rapid cutaneous vasodilator response to local heating.

    PubMed

    Tew, Garry A; Saxton, John M; Klonizakis, Markos; Moss, James; Ruddock, Alan D; Hodges, Gary J

    2011-05-01

    Sedentary aging results in a diminished rapid cutaneous vasodilator response to local heating. We investigated whether this diminished response was due to altered contributions of noradrenergic sympathetic nerves by assessing 1) the age-related decline and 2) the effect of aerobic fitness. Using laser-Doppler flowmetry, we measured skin blood flow (SkBF) in young (24 ± 1 yr) and older (64 ± 1 yr) endurance-trained and sedentary men (n = 7 per group) at baseline and during 35 min of local skin heating to 42°C at 1) untreated forearm sites, 2) forearm sites treated with bretylium tosylate (BT), which prevents neurotransmitter release from noradrenergic sympathetic nerves, and 3) forearm sites treated with yohimbine + propranolol (YP), which antagonizes α- and β-adrenergic receptors. SkBF was converted to cutaneous vascular conductance (CVC = SkBF/mean arterial pressure) and normalized to maximal CVC (%CVC(max)) achieved by skin heating to 44°C. Pharmacological agents were administered using microdialysis. In the young trained group, the rapid vasodilator response was reduced at BT and YP sites (P < 0.05); by contrast, in the young sedentary and older trained groups, YP had no effect (P > 0.05), but BT did (P > 0.05). Neither BT nor YP affected the rapid vasodilator response in the older sedentary group (P > 0.05). These data suggest that the age-related reduction in the rapid vasodilator response is due to an impairment of sympathetic-dependent mechanisms, which can be partly attenuated with habitual aerobic exercise. Rapid vasodilation involves noradrenergic neurotransmitters in young trained men and nonadrenergic sympathetic cotransmitters (e.g., neuropeptide Y) in young sedentary and older trained men, possibly as a compensatory mechanism. Finally, in older sedentary men, the rapid vasodilation appears not to involve the sympathetic system.

  2. Surface Features Analysis in Salt-Affected Area Using Hyperspectral Data: A Case Study in the Zone of Chotts, Tunisia

    NASA Astrophysics Data System (ADS)

    Bouaziz, Moncef; Liesenberg, Veraldo; Bouaziz, Samir; Gloaguen, Richard

    2010-12-01

    Arid and semi-arid regions are most affected by Salinity. Chotts regions in southern Tunisia are such an area, where the excessive content of salt in the soil is a hard faced problem. Soil salinity in this area enforces several environmental problems such as limiting plant growth, reducing crop productivity, degrading soil quality and leads to accelerated rates rill and gully erosion . Remote sensing analysis by the mean of spectral analysis, geomorphologic aspect from digital elevation models and distribution of rainfall intensity from satellite data are used in this study to discern features and patterns of areas affected by salt. Correlation between these remote sensing indicators is made in order to assess the contribution of each indicator to identify the salt-affected area. The approach followed in this study was applied on Hyperspectral data from EO-1 Mission. Hyperion data are promoted due to their very high spectral resolution and wide enhanced spatial information. The present study highlighted the high correlation between the flat surfaces and the high content of salt in the soil (from soil salinity indices) on one hand and a low correlation between the high intensity of rainfall distribution and indicators of low salt content in the soil on the other hand.

  3. Heating up Climate Literacy Education: Understanding Teachers' and Students' Motivational and Affective Response to Climate Change

    NASA Astrophysics Data System (ADS)

    Sinatra, G. M.

    2011-12-01

    Changing students' ideas about controversial scientific issues, such as human-induced climate change, presents unique challenges for educators (Lombardi & Sinatra, 2010; Sinatra & Mason, 2008). First, climate science is complex and requires "systems thinking," or the ability to think and reason abstractly about emergent systems (Goldstone & Sakamoto, 2003). Appreciating the intricacies of complex systems and emergent processes has proven challenging for students (Chi, 2005). In addition to these challenges, there are specific misconceptions that may lead thinking astray on the issue of global climate change, such as the distinction between weather and climate (Lombardi & Sinatra, 2010). As an example, when students are asked about their views on climate change, they often recall individual storm events or very cold periods and use their personal experiences and recollections of short-term temperature fluctuations to assess whether the planet is warming. Beyond the conceptual difficulties, controversial topics offer another layer of challenge. Such topics are often embedded in complex socio-cultural and political contexts, have a high degree of uncertainty, and may be perceived by individuals as in conflict with their personal or religious beliefs (Levinson, 2006, Sinatra, Kardash, Taasoobshirazi, & Lombardi, 2011). Individuals are often committed to their own views on socio-scientific issues and this commitment may serve as a motivation to actively resist new ideas (Dole & Sinatra, 1998). Individuals may also have strong emotions associated with their misconceptions (Broughton, Pekrun, & Sinatra, 2011). Negative emotions, misconceptions, and resistance do not make a productive combination for learning. Further, teachers who find human-induced climate change implausible have been shown to hold negative emotions about having to teach about climate change (Lombardi & Sinatra, in preparation), which could affect how they present the topic to students. In this

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

    USGS Publications Warehouse

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  6. Factors affecting the synergy of thiabendazole, sodium bicarbonate, and heat to control postharvest green mold of citrus fruit.

    PubMed

    Schirra, Mario; D'Aquino, Salvatore; Palma, Amedeo; Angioni, Alberto; Cabras, Paolo

    2008-11-26

    The efficacy of thiabendazole (TBZ) to control postharvest decay caused by Penicillium digitatum of citrus fruit can be enhanced by co-application with sodium bicarbonate (SBC) and/or heat treatment. The impact of these treatments was investigated in citrus fruit, as a function of TBZ and SBC concentration and temperature, and were related to the amount of TBZ residues in fruit (total residues), in fruit surface, in the cuticular wax, and in the inner fruit. The residue levels of TBZ were determined in 'Valencia' oranges following a 1 min dip in an aqueous mixture of SBC at 0.5, 1, or 2 wt %/vol and TBZ at 600 or 400 mg/L (active ingredient, a.i.) at 20 or 40 degrees C and after 0 and 20 days at 17 degrees C and 90% relative humidity. The influence of SBC and heat on the TBZ residue concentration on the fruit surface, in cuticular wax, and on the inner cuticle tissue was determined in 'Salustiana' oranges after a 1 or 3 min dip in TBZ alone at 600 mg/L and 20 or 50 degrees C or for 1 min in TBZ at 600 mg/L and SBC at 2% and 20 degrees C. The efficacy of heat treatments with water, SBC, and TBZ, applied separately or in combination, was investigated on artificially inoculated 'Nova' mandarins and 'Valencia' oranges for the control of postharvest green mold caused by a TBZ-sensitive (TBZ-s) or TBZ-resistant (TBZ-r) isolate of P. digitatum. The residue levels of TBZ in fruit, evaluated as total residues, were not affected by the co-application of SBC in most samples. While TBZ residues in the fruit surface were not significantly affected by the dip temperature or by co-application of SBC, the rates of diffusion and penetration of TBZ into cuticular wax markedly increased in the presence of SBC or when TBZ was applied in combination with heat. TBZ residues in the inner tissue of fruits treated at 20 degrees C were not dependent upon the dip time or by the presence of SBC and were similar to those found in fruit treated with TBZ at 50 degrees C for 1 min, whereas

  7. Why person affected by leprosy did not look after their plantar ulcer? Experience from Pakokku zone, Myanmar.

    PubMed

    Win, Le Le; Shwe, San; Maw, Win; Ishida, Yutaka; Myint, Kyaw; Mar, Kyi Kyi; Min, Thandar; Oo, Phyo Min; Khine, Aye Win

    2010-09-01

    A cross-sectional study was carried out to identify methods of caring plantar ulcers in leprosy patients and the underlying causes of poor plantar ulcer care during January and February 2008. This was conducted in Pakokku zone as it was one of the "9 selected townships of the Disabilities survey, i.e., Basic Health Staff project 2003/4", which was funded by Japan International Cooperation Agency. After getting consent, all available leprosy cases, i.e., 101 cases with foot disability grade 2 were interviewed with the pre-tested questionnaire. Among 101 cases, 13 cases who took care of their ulcer poorly and 20 who did none of the recommended measures were recruited for in-depth interview (IDI). The subjects were largely old people, males and people with no marriage partner. The majority had earned money by doing sedentary job. Prolongation of ulcers was observed in 78 cases. Most had been suffering from ulcers for years. When asking face-to-face interview, all the recommended care measures were not reported. Among these recommended measures, a large number of respondents reported about soaking measure. However, these reported measures were contradicted to the preventive methods which they disclosed in IDI. Plantar ulcer care seemed to be an individualised practice. The individual ways of performing were related to their view of ulcer, the environment, and occupation, and custom, communication with family and health staff. The findings identified the actual practice of plantar ulcer care in study areas. It is suggested that the current performance of planar ulcer care is inadequate and more attention should be given to achieve the target set by the programme as a recommendation.

  8. Differences in Water Vapor Radiative Transfer among 1D Models Can Significantly Affect the Inner Edge of the Habitable Zone

    NASA Astrophysics Data System (ADS)

    Yang, Jun; Leconte, Jérémy; Wolf, Eric T.; Goldblatt, Colin; Feldl, Nicole; Merlis, Timothy; Wang, Yuwei; Koll, Daniel D. B.; Ding, Feng; Forget, François; Abbot, Dorian S.

    2016-08-01

    An accurate estimate of the inner edge of the habitable zone is critical for determining which exoplanets are potentially habitable and for designing future telescopes to observe them. Here, we explore differences in estimating the inner edge among seven one-dimensional radiative transfer models: two line-by-line codes (SMART and LBLRTM) as well as five band codes (CAM3, CAM4_Wolf, LMDG, SBDART, and AM2) that are currently being used in global climate models. We compare radiative fluxes and spectra in clear-sky conditions around G and M stars, with fixed moist adiabatic profiles for surface temperatures from 250 to 360 K. We find that divergences among the models arise mainly from large uncertainties in water vapor absorption in the window region (10 μm) and in the region between 0.2 and 1.5 μm. Differences in outgoing longwave radiation increase with surface temperature and reach 10-20 W m-2 differences in shortwave reach up to 60 W m-2, especially at the surface and in the troposphere, and are larger for an M-dwarf spectrum than a solar spectrum. Differences between the two line-by-line models are significant, although smaller than among the band models. Our results imply that the uncertainty in estimating the insolation threshold of the inner edge (the runaway greenhouse limit) due only to clear-sky radiative transfer is ≈10% of modern Earth’s solar constant (i.e., ≈34 W m-2 in global mean) among band models and ≈3% between the two line-by-line models. These comparisons show that future work is needed that focuses on improving water vapor absorption coefficients in both shortwave and longwave, as well as on increasing the resolution of stellar spectra in broadband models.

  9. Natural Radiation for Identification and Evaluation of Risk Zones for Affectation of Activated Faults in Aquifer Overexploited.

    NASA Astrophysics Data System (ADS)

    Ramos-Leal, J.; Lopez-Loera, H.; Carbajal-Perez, N.

    2007-05-01

    In basins as Mexico, Michoacán, Guanajuato, Queretaro, Aguascalientes and San Luis Potosi, the existence of faults and fractures have affected the urban infrastructure, lines of conduction of drinkable water, pipelines, etc., that when not being identified and considered, they don't reflect the real impact that these cause also to the aquifer system, modifying the permeability of the means and in occasions they work as preferential conduits that communicate hydraulically potentially to the aquifer with substances pollutants (metals, fertilizers, hydrocarbons, waste waters, etc.) located in the surface. In the Valley of San Luis Potosi, Villa of Reyes, Arista, Ahualulco and recently The Huizache-Matehuala is being strongly affected by faulting and supposedly due cracking to subsidence, however, the regional tectonic could also be the origin of this phenomenon. To know the origin of the faults and affectation to the vulnerability of the aquifer few works they have been carried out in the area. A preliminary analysis indicates that it is possible that a tectonic component is affecting the area and that the vulnerability of the aquifer in that area you this increasing. Before such a situation, it is necessary to carry out the isotopic study of the same one, for this way to know among other things, isotopic characterization, recharge places and addresses of flow of the groundwater; quality of waters and the behavior hydrochemistry with relationship to the faults. High radon values were measured in San Luis Potosi Valley, the natural source of radon could be the riolites and however, these are located to almost a once thousand meters deep for what the migration of the gas is not very probable. The anomalies radiometrics was not correlation with the faults in this case. In some areas like the Valley of Celaya, the origin of the structures and the tectonic activity in the area was confirmed, identifying the structural arrangement of the faulting, the space relationships

  10. Virus removal within a soil infiltration zone as affected by effluent composition, application rate, and soil type.

    PubMed

    Van Cuyk, Sheila; Siegrist, Robert L

    2007-02-01

    The column studies presented in this paper simulated the infiltrative surface of onsite wastewater systems where effluent is applied and where a biomat may form. Two bacteriophages, MS-2 and PRD-1, were used as surrogates for human pathogenic enteric viruses during two tracer tests. A vacuum manifold was used to simulate the drainage effects of an underlying unsaturated soil profile, allowing for the collection of percolate samples at 4 cm immediately below the infiltrative surface. The impact of effluent applied (septic tank effluent (STE) or a simulated ground water), soil type (medium sand or sandy loam), hydraulic loading rate (5 or 25 cm/day) and method of application (four equivalent daily doses or 24 equivalent micro-doses per day) on the removal of viruses were investigated. These unsaturated mini column experiments demonstrated that the removal of viruses within an infiltrative surface zone (of approximately 4 cm) generally improved over time under the conditions studied. An exception occurred in sand-filled columns dosed with STE where the removal of PRD-1 decreased after a period of effluent application. Statistical analysis conducted on the calculated percent removal demonstrated that the quality of the effluent applied to the infiltrative surface is important for removal of MS-2 and PRD-1. Hydraulic loading rate also proved important in the removal of viruses. At the time of tracer test 2, columns dosed at the higher HLR (25 cm/day) had higher percent removals for both MS-2 and PRD-1. Soil type altered the removal of PRD-1 at the time of the second tracer test, at which time sandy loam had higher removal rates for PRD-1. No significant differences were observed between columns dosed four times daily and those dosed 24 times daily for either bacteriophage at either of the tracer test time points. These data suggest that over a relatively short period of operation the infiltrative surface of soil based wastewater treatment systems can achieve much higher

  11. Exploiting zone trapping to avoid liberation of air bubbles in flow-based analytical procedures requiring heating.

    PubMed

    Vida, Ana C F; Zagatto, Elias A G

    2014-01-01

    In flow-based analytical procedures requiring heating, liberation of air bubbles is avoided by trapping a sample selected portion into a heated hermetic environment. The flow-through cuvette is maintained into a temperature-controlled aluminium block, thus acting as the trapping element and allowing real-time monitoring. The feasibility of the innovation was demonstrated in the spectrophotometric catalytic determination of vanadium in mineral waters. Air bubbles were not released even for temperatures as high as 95°C. The proposed system handles about 25 samples per hour, requires only 3 mg p-anisidine per determination and yields precise results (r.s.d. = 2.1%), in agreement with ICP-MS. Detection limit was evaluated (3.3 σ criterion) as 0.1 μg L(-1) V.

  12. Design requirements for ERD in diffusion-dominated media: how do injection interval, bioactive zones and reaction kinetics affect remediation performance?

    NASA Astrophysics Data System (ADS)

    Chambon, J.; Lemming, G.; Manoli, G.; Broholm, M. M.; Bjerg, P.; Binning, P. J.

    2011-12-01

    Enhanced Reductive Dechlorination (ERD) has been successfully used in high permeability media, such as sand aquifers, and is considered to be a promising technology for low permeability settings. Pilot and full-scale applications of ERD at several sites in Denmark have shown that the main challenge is to get contact between the injected bacteria and electron donor and the contaminants trapped in the low-permeability matrix. Sampling of intact cores from the low-permeability matrix has shown that the bioactive zones (where degradation occurs) are limited in the matrix, due to the slow diffusion transport processes, and this affects the timeframes for the remediation. Due to the limited ERD applications and the complex transport and reactive processes occurring in low-permeability media, design guidelines are currently not available for ERD in such settings, and remediation performance assessments are limited. The objective of this study is to combine existing knowledge from several sites with numerical modeling to assess the effect of the injection interval, development of bioactive zones and reaction kinetics on the remediation efficiency for ERD in diffusion-dominated media. A numerical model is developed to simulate ERD at a contaminated site, where the source area (mainly TCE) is located in a clayey till with fractures and interbedded sand lenses. Such contaminated sites are common in North America and Europe. Hydro-geological characterization provided information on geological heterogeneities and hydraulic parameters, which are relevant for clay till sites in general. The numerical model couples flow and transport in the fracture network and low-permeability matrix. Sequential degradation of TCE to ethene is modeled using Monod kinetics, and the kinetic parameters are obtained from laboratory experiments. The influence of the reaction kinetics on remediation efficiency is assessed by varying the biomass concentration of the specific degraders. The injected

  13. Effect of Heat Treatment on Residual Stresses in the Zone of Fusion of Austenitic and Vessel Steels

    NASA Astrophysics Data System (ADS)

    Khlybov, A. A.

    2016-11-01

    The effect of heat treatment on the structure and physical and mechanical properties of flat specimens cut from a massive billet from steel 15Kh2MFA with an austenitic facing on one side is studied. The hardness and the microhardness of the specimens are determined. Acoustic and x-ray studies are performed. The causes of residual stresses giving rise to deformation and formation of cracks in the faced steel are established. Ways to solve the problem are suggested.

  14. The dynamical oscillation and propulsion of magnetic fields in the convective zone of a star. II - Thermal shadows. III - Accumulation of heat and the onset of the Rayleigh-Taylor instability

    NASA Technical Reports Server (NTRS)

    Parker, E. N.

    1987-01-01

    The dynamics of thermal shadows which develop in the convective zone of a star around an insulating obstacle such as a horizontal band in intense magnetic field are studied. The depth of the shadow on the cool side of the obstacle is found to depend largely on the width of the obstacle multiplied by the temperature gradient. Thermal shadows pressing fields up to 10,000 G downward against the bottom of the convective zone are produced by the broad bands of the azimuthal field in the sun's convective zone. In the third part, the time-dependent accumulation of heat beneath a thermal barrier simulating such a band in the lower convective zone of the sun is considered. The resulting Rayleigh-Taylor instability is shown to cause tongues of heated gas to penetrate upward through the field, providing the emerging magnetic fields that give rise to the activity of the sun.

  15. Hydrogeologic factors that affect the flowpath of water in selected zones of the Edwards Aquifer, San Antonio region, Texas

    USGS Publications Warehouse

    Groschen, G.E.

    1996-01-01

    The Edwards aquifer in the San Antonio region supplies drinking water for more than 1 million people. Proper development and protection of the aquifer is a high priority for local and State authorities. To better understand the flow of water in two major flowpaths in the Edwards aquifer, stratigraphic, structural, hydrologic, and geochemical data were analyzed. The western Medina flowpath is in parts of Uvalde, Medina, and Bexar Counties, and the eastern flowpath is in northern Bexar and central Comal Counties. A major hydrogeologic factor that affects the pattern of flow in the Edwards aquifer is the spatial and temporal distribution of recharge. Other hydrogeologic factors that affect flowpaths include internal boundaries and the location and rate of spring discharge. The relative displacement of faults and the high permeability layers have substantial control on the discharge at springs and on the flowpaths in the Edwards aquifer. Analysis of the estimated recharge to the Edwards aquifer during 1982 89 indicated that during years of substantial precipitation, a large part of the net recharge probably is diffuse infiltration of precipitation over large parts of the recharge area. During years with below-normal precipitation, most recharge is leakage from rivers and streams that drain the catchment subbasins. In the western Medina flowpath, concentrations of major ions indicate saturation of calcite and undersaturation of dolomite the two minerals that constitute most of the Edwards aquifer matrix. Concentrations of dissolved calcium, alkalinity, and dissolved chloride in the eastern flowpath are greater than those in the western Medina flowpath. These upward trends in concentrations might result in part from: (1) increased development in the recharge area, (2) mineralized effluent from developed areas, or (3) increased dissolution of aquifer material. Tritium data from wells sampled in and near the western Medina flowpath indicate no vertical stratification of

  16. Formation of the seed layers for layer-transfer process silicon solar cells by zone-heating recrystallization of porous silicon structures

    NASA Astrophysics Data System (ADS)

    Lukianov, A.; Murakami, K.; Takazawa, C.; Ihara, M.

    2016-05-01

    Thin-film crystalline silicon is promising for photovoltaic application to reduce the cost of photovoltaic energy. Porous silicon structures have been intensively studied as a seed layer for epitaxial growth of thin Si film and layer-transfer process (LTP). In this article, another approach for LTP has been proposed. The seed layers for epitaxial silicon growth have been formed by zone-heating recrystallization of double-layer por-Si structures. The influence of annealing parameters on porous silicon structures was studied. The transformation of por-Si layer to crystalline Si was observed with the formation of smooth continuous surface with the roughness 0.3 nm, peak-to-valley distance around 3.5 nm, and reduced density of pores. The mechanism of the transformation of por-Si surface due to the action of hydrogen in the passivated pores with preventing surface oxidation was proposed.

  17. Single-dose oral quercetin improves redox status but does not affect heat shock response in mice.

    PubMed

    Chen, Yifan; Islam, Aminul; Abraham, Preetha; Deuster, Patricia

    2014-07-01

    Inflammation and oxidative stress are considered as likely contributors to heat injury. However, their roles in regulating the heat shock response in vivo remain unclear. We tested the hypothesis that acute quercetin treatment would improve redox status and reduce heat shock responses in mice. Mice underwent two heat tests before and after single oral administration of either quercetin (15 mg/kg) or vehicle. We measured physiologic and biochemical responses in mice during and 18 to 22 hours after heat tests, respectively. There were no significant differences in core temperature, heart rate, or blood pressure between quercetin and vehicle groups during heat exposure. Mice with relatively severe hyperthermia during the pretreatment heat test showed a significant trend toward a lower peak core temperature during the heat test after quercetin treatment. Compared with mice not exposed to heat, quercetin-treated mice had significantly lower interleukin 6 (P < .01) and higher superoxide dismutase levels (P < .01), whereas vehicle-treated mice had significantly lower total glutathione and higher 8-isoprostane levels in the circulation after heat exposure. Heat exposure significantly elevated heat shock proteins (HSPs) 72 and 90 and heat shock factor 1 levels in mouse liver, heart, and skeletal muscles, but no significant differences in tissue HSPs and heat shock factor 1 were found between quercetin- and vehicle-treated mice. These results suggest that a single moderate dose of quercetin is sufficient to alter redox status but not heat stress response in mice. Acute adaptations of peripheral tissues to heat stress may not be mediated by systemic inflammatory and redox state in vivo.

  18. Effect of heat input on the microstructure and mechanical properties of tungsten inert gas arc butt-welded AZ61 magnesium alloy plates

    SciTech Connect

    Min Dong; Shen Jun; Lai Shiqiang; Chen Jie

    2009-12-15

    In this paper, the effects of heat input on the microstructures and mechanical properties of tungsten inert gas arc butt-welded AZ61 magnesium alloy plates were investigated by microstructural observations, microhardness tests and tensile tests. The results show that with an increase of the heat input, the grains both in the fusion zone and the heat-affected zone coarsen and the width of the heat-affected zone increased. Moreover, an increase of the heat input resulted in a decrease of the continuous {beta}-Mg{sub 17}Al{sub 12} phase and an increase of the granular {beta}-Mg{sub 17}Al{sub 12} phase in both the fusion zone and the heat-affected zone. The ultimate tensile strength of the welded joint increased with an increase of the heat input, while, too high a heat input resulted in a decrease of the ultimate tensile strength of the welded joint. In addition, the average microhardness of the heat-affected zone and fusion zone decreased sharply with an increase of the heat input and then decreased slowly at a relatively high heat input.

  19. Short-term heat shock affects the course of immune response in Galleria mellonella naturally infected with the entomopathogenic fungus Beauveria bassiana.

    PubMed

    Vertyporokh, Lidiia; Taszłow, Paulina; Samorek-Pieróg, Małgorzata; Wojda, Iwona

    2015-09-01

    We aimed to investigate how exposition of infected insects to short-term heat shock affects the biochemical and molecular aspects of their immune response. Galleria mellonella larvae were exposed to 43°C for 15min, at the seventy second hour after natural infection with entomopathogenic fungus Beauveria bassiana. As a result, both qualitative and quantitative changes in hemolymph protein profiles, and among them infection-induced changes in the amount of apolipophorin III (apoLp-III), were observed. Heat shock differently affects the expression of the tested immune-related genes. It transiently inhibits expression of antifungal peptides gallerimycin and galiomicin in both the fat body and hemocytes of infected larvae. The same, although to a lesser extent, concerned apoLp-III gene expression and was observed directly after heat shock. Nevertheless, in larvae that had recovered from heat shock, apoLp-III expression was higher in comparison to unshocked larvae in the fat body but not in hemocytes, which was consistent with the higher amount of this protein detected in the hemolymph of the infected, shocked larvae. Furthermore, lysozyme-type activity was higher directly after heat shock, while antifungal activity was significantly higher also in larvae that had recovered from heat shock, in comparison to the respective values in their non-shocked, infected counterparts. These results show how changes in the external temperature modulate the immune response of G. mellonella suffering from infection with its natural pathogen B. bassiana.

  20. The thermoneutral zone: implications for metabolic studies.

    PubMed

    Kingma, Boris; Frijns, Arjan; van Marken Lichtenbelt, Wouter

    2012-01-01

    A thermoneutral environment is important for many human physiological studies. The thermoneutral zone (TNZ) is defined as the range of ambient temperatures without regulatory changes in metabolic heat production or evaporative heat loss. Many factors influence the thermoneutral zone, such as body composition, clothing, energy expenditure, age and gender. These factors have the potential to introduce bias in study results and therefore need to be taken into consideration in many metabolic studies or studies on obesity, medical conditions, thermal comfort or vigilance. Given new developments on the TNZ combined with historical views the aim of this review is to 1) provide insight in how the human TNZ is affected by internal and external factors, 2) indicate how skin blood flow characteristics could be used as an objective criterion for determining whether someone is in the thermoneutral zone, 3) explain implications of the TNZ on metabolic studies and 4) indicate future directions to enhance understanding of the TNZ, especially for the elderly and obese.

  1. Ionizing Radiation Perturbs Cell Cycle Progression of Neural Precursors in the Subventricular Zone Without Affecting Their Long-Term Self-Renewal.

    PubMed

    Chen, Hongxin; Goodus, Matthew T; de Toledo, Sonia M; Azzam, Edouard I; Levison, Steven W; Souayah, Nizar

    2015-01-01

    Damage to normal human brain cells from exposure to ionizing radiation may occur during the course of radiotherapy or from accidental exposure. Delayed effects may complicate the immediate effects resulting in neurodegeneration and cognitive decline. We examined cellular and molecular changes associated with exposure of neural stem/progenitor cells (NSPs) to (137)Cs γ-ray doses in the range of 0 to 8 Gy. Subventricular zone NSPs isolated from newborn mouse pups were analyzed for proliferation, self-renewal, and differentiation, shortly after irradiation. Strikingly, there was no apparent increase in the fraction of dying cells after irradiation, and the number of single cells that formed neurospheres showed no significant change from control. Upon differentiation, irradiated neural precursors did not differ in their ability to generate neurons, astrocytes, and oligodendrocytes. By contrast, progression of NSPs through the cell cycle decreased dramatically after exposure to 8 Gy (p < .001). Mice at postnatal day 10 were exposed to 8 Gy of γ rays delivered to the whole body and NSPs of the subventricular zone were analyzed using a four-color flow cytometry panel combined with ethynyl deoxyuridine incorporation. Similar flow cytometric analyses were performed on NSPs cultured as neurospheres. These studies revealed that neither the percentage of neural stem cells nor their proliferation was affected. By contrast, γ-irradiation decreased the proliferation of two classes of multipotent cells and increased the proliferation of a specific glial-restricted precursor. Altogether, these results support the conclusion that primitive neural precursors are radioresistant, but their proliferation is slowed down as a consequence of γ-ray exposure.

  2. Arbuscular mycorrhizal fungal communities in sub-Saharan savannas of Benin, West Africa, as affected by agricultural land use intensity and ecological zone.

    PubMed

    Tchabi, Atti; Coyne, Danny; Hountondji, Fabien; Lawouin, Louis; Wiemken, Andres; Oehl, Fritz

    2008-04-01

    The rapid decline of soil fertility of cultivated lands in the sub-Saharan savannas of West Africa is considered to be the main cause of the increasingly severe constraints of food production. The soils in this tropical area are highly fragile, and crop yields are limited by characteristically low levels of available phosphorus. Under such preconditions, the multiple benefits of the arbuscular mycorrhizal (AM) symbiosis are likely to play a pivotal role for maintaining natural soil fertility by enhancing plant nutrient use efficiency, plant health, and stabilization of a favorable soil structure. Thus, it is important to explore the impact of the commonly applied farming practices on the native AM fungal community. In the present study, we determined the AM fungal species composition in three ecological zones differing by an increasingly prolonged dry season from South to North, from the Southern Guinea Savanna (SG), to the Northern Guinea Savanna (NG), to the Sudan Savanna (SU). In each zone, four "natural" and four "cultivated" sites were selected. "Natural" sites were three natural forest savannas (at least 25-30 years old) and a long-term fallow (6-7 years old). "Cultivated" sites comprised a field with yam (Dioscorea spp.) established during the first year after forest clearance, a field under mixed cropping with maize (Zea mays) and peanut (Arachis hypogaea), a field under peanut, and a field under cotton (Gossypium hirsutum) which was the most intensively managed crop. Soil samples were collected towards the end of the wet season in each zone. AM fungal spores were extracted and morphologically identified. Soil subsamples were used to inoculate AM fungal trap cultures using Stylosanthes guianensis and Brachiaria humidicola as host plants to monitor AM root colonization and spore formation over 10 and 24 months, respectively. A total of 60 AM fungal species were detected, with only seven species sporulating in the trap cultures. Spore density and species

  3. A laser gyro with a four-mirror square resonator: formulas for simulating the dynamics of the synchronisation zone parameters of the frequencies of counterpropagating waves during the device operation in the self-heating regime

    SciTech Connect

    Bondarenko, E A

    2014-04-28

    For a laser gyro with a four-mirror square resonator we have developed a mathematical model, which allows one to simulate the temporal behaviour of the synchronisation zone parameters of the frequencies of counterpropagating waves in a situation when the device operates in the self-heating regime and is switched-on at different initial temperatures. (laser gyroscopes)

  4. Residual analysis in the determination of factors affecting the estimates of body heat storage in clothed subjects.

    PubMed

    Aoyagi, Y; McLellan, T M; Shephard, R J

    1996-01-01

    Body heat storage can be estimated by calorimetry (from heat gains and losses) or by thermometry [from changes (delta) in mean body temperature (T b) calculated as a weighted combination of rectal (Tre) and mean skin temperatures (T sk)]. If an invariant weighting factor of Tre and T sk were to be used (for instance, delta T b = 0.8.delta Tre + 0.2 delta T sk under hot conditions), body heat storage could be over- or underestimated substantially relative to calorimetry, depending on whether the subject was wearing light or protective clothing. This study investigated whether discrepancies between calorimetry and thermometry arise from methodological errors in the calorimetric estimate of heat storage, from inappropriate weightings in the thermometric estimate, or from both. Residuals of calorimetry versus thermometric estimates were plotted against individual variables in the standard heat balance equation, applying various weighting factors to Tre and T sk. Whether light or protective clothing was worn, the calorimetric approach generally gave appropriate estimates of heat exchange components and thus heat storage. One exception was in estimating latent heat loss from sweat evaporation. If sweat evaporation exceeded 650 g.h-1 when wearing normal clothing, evaporative heat loss was overestimated and thus body heat storage was underestimated. Nevertheless, if data beyond this ceiling were excluded from the analyses, the standard 4:1 weighting matched calorimetric heat storage estimates quite well. When wearing protective clothing, the same 4:1 weighting approximated calorimetric heat storage with errors of less than approximately 10%, but only if environmental conditions allowed a subject to exercise for more than 90 min. The best thermometric estimates of heat storage were provided by using two sets of relative weightings, based upon the individual's metabolic heat production (M in kilojoules per meter squared per hour): (4 - [(M - x).x-1].2): 1 for an initial

  5. Twin Convergence Zones

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's QuikSCAT satellite has confirmed a 30-year old largely unproven theory that there are two areas near the equator where the winds converge year after year and drive ocean circulation south of the equator. By analyzing winds, QuikSCAT has found a year-round southern and northern Intertropical Convergence Zone. This find is important to climate modelers and weather forecasters because it provides more detail on how the oceans and atmosphere interact near the equator. The Intertropical Convergence Zone (ITCZ) is the region that circles the Earth near the equator, where the trade winds of both the Northern and Southern Hemispheres come together. North of the equator, strong sun and warm water of the equator heats the air in the ITCZ, drawing air in from north and south and causing the air to rise. As the air rises it cools, releasing the accumulated moisture in an almost perpetual series of thunderstorms. Satellite data, however, has confirmed that there is an ITCZ north of the equator and a parallel ITCZ south of the equator. Variation in the location of the ITCZ is important to people around the world because it affects the north-south atmospheric circulation, which redistributes energy. It drastically affects rainfall in many equatorial nations, resulting in the wet and dry seasons of the tropics rather than the cold and warm seasons of higher latitudes. Longer term changes in the ITCZ can result in severe droughts or flooding in nearby areas. 'The double ITCZ is usually only identified in the Pacific and Atlantic Oceans on a limited and seasonal basis,' said Timothy Liu, of NASA's Jet Propulsion Laboratory and California Institute of Technology, Pasadena, Calif., and lead researcher on the project. In the eastern Pacific Ocean, the southern ITCZ is usually seen springtime. In the western Atlantic Ocean, the southern ITCZ was recently clearly identified only in the summertime. However, QuikSCAT's wind data has seen the southern ITCZ in all seasons across the

  6. Modulation of heat shock protein 90 affects TGF-β-induced collagen synthesis in human dermal fibroblast cells.

    PubMed

    Lee, Sae Bin; Lim, A-Ram; Rah, Dong Kyun; Kim, Kyung Soo; Min, Hyun Jin

    2016-12-01

    Heat shock protein 90 is a chaperone molecule that aids in proper folding of target proteins. Recently, heat shock protein 90 was found to play a role in would healing through regulation of fibroblast functions. The aim of the present study was to investigate the role of heat shock protein 90 in collagen synthesis in human dermal fibroblasts. The effects of transforming growth factor-β, 17-N-allylamino-17-demethoxygeldanamycin, and transfection of heat shock protein 90 were evaluated by real-time PCR, western blot, and immunofluorescence assays. The Smad 2/3 and Akt pathways were evaluated to identify the signaling pathways involved in collagen synthesis. Heat shock protein 90 and collagen levels were compared in keloid and control tissues by immunohistochemical analysis. The expression of collagen was significantly increased after treatment with transforming growth factor-β, while 17-N-allylamino-17-demethoxygeldanamycin inhibited transforming growth factor-β-induced collagen synthesis. Overexpression of heat shock protein 90 itself with or without transforming growth factor-β increased collagen synthesis. These effects were dependent on Smad 2/3 pathway signaling. Finally, expression of heat shock protein 90 was increased in keloid tissue compared with control tissues. Taken together, these results demonstrate that modulation of heat shock protein 90 influences transforming growth factor-β-induced collagen synthesis via regulation of Smad 2/3 phosphorylation.

  7. Proteins associated with heat-induced leaf senescence in creeping bentgrass as affected by foliar application of nitrogen, cytokinins, and an ethylene inhibitor.

    PubMed

    Jespersen, David; Huang, Bingru

    2015-02-01

    Heat stress causes premature leaf senescence in cool-season grass species. The objective of this study was to identify proteins regulated by nitrogen, cytokinins, and ethylene inhibitor in relation to heat-induced leaf senescence in creeping bentgrass (Agrostis stolonifera). Plants (cv. Penncross) were foliar sprayed with 18 mM carbonyldiamide (N source), 25 μM aminoethoxyvinylglycine (AVG, ethylene inhibitor), 25 μM zeatin riboside (ZR, cytokinin), or a water control, and then exposed to 20/15°C (day/night) or 35/30°C (heat stress) in growth chambers. All treatments suppressed heat-induced leaf senescence, as shown by higher turf quality and chlorophyll content, and lower electrolyte leakage in treated plants compared to the untreated control. A total of 49 proteins were responsive to N, AVG, or ZR under heat stress. The abundance of proteins in photosynthesis increased, with ribulose-1,5-bisphosphate carboxylase/oxygenase affected by all three treatments, chlorophyll a/b-binding protein by AVG and N or Rubisco activase by AVG. Proteins for amino acid metabolism were upregulated, including alanine aminotransferase by three treatments and ferredoxin-dependent glutamate synthase by AVG and N. Upregulated proteins also included catalase by AVG and N and heat shock protein by ZR. Exogenous applications of AVG, ZR, or N downregulated proteins in respiration (enolase, glyceraldehyde 3-phosphate dehydrogenase, and succinate dehygrogenase) under heat stress. Alleviation of heat-induced senescence by N, AVG, or ZR was associated with enhanced protein abundance in photosynthesis and amino acid metabolism and stress defense systems (heat shock protection and antioxidants), as well as suppression of those imparting respiration metabolism.

  8. Evidence of multi-stage faulting by clay mineral analysis: Example in a normal fault zone affecting arkosic sandstones (Annot sandstones)

    NASA Astrophysics Data System (ADS)

    Buatier, Martine D.; Cavailhes, Thibault; Charpentier, Delphine; Lerat, Jérémy; Sizun, Jean Pierre; Labaume, Pierre; Gout, Claude

    2015-06-01

    Fault affecting silicoclastic sediments are commonly enriched in clay minerals. Clays are sensitive to fluid-rock interactions and deformation mechanisms; in this paper, they are used as proxy for fault activity and behavior. The present study focuses on clay mineral assemblages from the Point Vert normal fault zone located in the Annot sandstones, a Priabonian-Rupelian turbidite succession of the Alpine foredeep in SE France. In this area, the Annot sandstones were buried around 6-8 km below the front of Alpine nappes soon after their deposition and exhumed during the middle-late Miocene. The fault affects arkosic sandstone beds alternating with pelitic layers, and displays throw of about thirty meters. The fault core zone comprises intensely foliated sandstones bounding a corridor of gouge about 20 cm thick. The foliated sandstones display clay concentration along S-C structures characterized by dissolution of K-feldspar and their replacement by mica, associated with quartz pressure solution, intense microfracturation and quartz vein precipitation. The gouge is formed by a clayey matrix containing fragments of foliated sandstones and pelites. However, a detailed petrographical investigation suggests complex polyphase deformation processes. Optical and SEM observations show that the clay minerals fraction of all studied rocks (pelites and sandstones from the damage and core zones of the fault) is dominated by white micas and chlorite. These minerals have two different origins: detrital and newly-formed. Detrital micas are identified by their larger shape and their chemical composition with a lower Fe-Mg content than the newly-formed white micas. In the foliated sandstones, newly-formed white micas are concentrated along S-C structures or replace K-feldspar. Both types of newly formed micas display the same chemical composition confirmed microstructural observations suggesting that they formed in the same conditions. They have the following structural formulas: Na0

  9. Will changes in root-zone temperature in boreal spring affect recovery of photosynthesis in Picea mariana and Populus tremuloides in a future climate?

    PubMed

    Fréchette, Emmanuelle; Ensminger, Ingo; Bergeron, Yves; Gessler, Arthur; Berninger, Frank

    2011-11-01

    Future climate will alter the soil cover of mosses and snow depths in the boreal forests of eastern Canada. In field manipulation experiments, we assessed the effects of varying moss and snow depths on the physiology of black spruce (Picea -mariana (Mill.) B.S.P.) and trembling aspen (Populus tremuloides Michx.) in the boreal black spruce forest of western Québec. For 1 year, naturally regenerated 10-year-old spruce and aspen were grown with one of the following treatments: additional N fertilization, addition of sphagnum moss cover, removal of mosses, delayed soil thawing through snow and hay addition, or accelerated soil thawing through springtime snow removal. Treatments that involved the addition of insulating moss or snow in the spring caused lower soil temperature, while removing moss and snow in the spring caused elevated soil temperature and thus had a warming effect. Soil warming treatments were associated with greater temperature variability. Additional soil cover, whether moss or snow, increased the rate of photosynthetic recovery in the spring. Moss and snow removal, on the other hand, had the opposite effect and lowered photosynthetic activity, especially in spruce. Maximal electron transport rate (ETR(max)) was, for spruce, 39.5% lower after moss removal than with moss addition, and 16.3% lower with accelerated thawing than with delayed thawing. Impaired photosynthetic recovery in the absence of insulating moss or snow covers was associated with lower foliar N concentrations. Both species were affected in that way, but trembling aspen generally reacted less strongly to all treatments. Our results indicate that a clear negative response of black spruce to changes in root-zone temperature should be anticipated in a future climate. Reduced moss cover and snow depth could adversely affect the photosynthetic capacities of black spruce, while having only minor effects on trembling aspen.

  10. Microgravity silicon zoning investigation

    NASA Technical Reports Server (NTRS)

    Kern, E. L.; Gill, G. L., Jr.

    1983-01-01

    A resistance heated zoner, suitable for early zoning experiments with silicon, was designed and put into operation. The initial power usage and size was designed for an shown to be compatible with payload carriers contemplated for the Shuttle. This equipment will be used in the definition and development of flight experiments and apparatus for float zoning silicon and other materials in microgravity.

  11. Oxidative stress in deep scattering layers: Heat shock response and antioxidant enzymes activities of myctophid fishes thriving in oxygen minimum zones

    NASA Astrophysics Data System (ADS)

    Lopes, Ana Rita; Trübenbach, Katja; Teixeira, Tatiana; Lopes, Vanessa M.; Pires, Vanessa; Baptista, Miguel; Repolho, Tiago; Calado, Ricardo; Diniz, Mário; Rosa, Rui

    2013-12-01

    Diel vertical migrators, such as myctophid fishes, are known to encounter oxygen minimum zones (OMZ) during daytime in the Eastern Pacific Ocean and, therefore, have to cope with temperature and oxidative stress that arise while ascending to warmer, normoxic surface waters at night-time. The aim of this study was to investigate the antioxidant defense strategies and heat shock response (HSR) in two myctophid species, namely Triphoturus mexicanus and Benthosema panamense, at shallow and warm surface waters (21 kPa, 20-25 °C) and at hypoxic, cold (≤1 kPa, 10 °C) mesopelagic depths. More specifically, we quantified (i) heat shock protein concentrations (HSP70/HSC70) (ii) antioxidant enzyme activities [including superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST)], and (iii) lipid peroxidation [malondialdehyde (MDA) levels]. HSP70/HSC70 levels increased in both myctophid species at warmer, well-oxygenated surface waters probably to prevent cellular damage (oxidative stress) due to increased oxygen demand under elevated temperatures and reactive oxygen species (ROS) formation. On the other hand, CAT and GST activities were augmented under hypoxic conditions, probably as preparatory response to a burst of oxyradicals during the reoxygenation phase (while ascending). SOD activity decreased under hypoxia in B. panamense, but was kept unchanged in T. mexicanus. MDA levels in B. panamense did not change between the surface and deep-sea conditions, whereas T. mexicanus showed elevated MDA and HSP70/HSC70 concentrations at warmer surface waters. This indicated that T. mexicanus seems to be not so well tuned to temperature and oxidative stress associated to diel vertical migrations. The understanding of such physiological strategies that are linked to oxygen deprivation and reoxygenation phases may provide valuable information about how different species might respond to the impacts of environmental stressors (e.g. expanding mesopelagic hypoxia

  12. Growth of high T{sub c} superconducting fibers using a minaturized laser-heated float zone process. Annual progress report, January 1, 1993--December 31, 1993

    SciTech Connect

    Feigelson, R.S.

    1993-12-01

    This report covers the research done on {open_quotes}Growth of High Tc Superconducting Fibers using a Miniaturized Laser-Heated Float Zone Process{close_quotes} during the 12 months from Jan. 1, 1993 until Dec. 31, 1993. The effort during this period were directed into two areas; the influence of growth conditions on the properties of the superconducting fibers and the construction of the advanced fiber growth station. In the first area of emphasis, studies were done on constitutional super cooling effect, the influence of processing parameters on Tc, the correlation between Tc and growth parameters and the mechanical properties of 2212 fibers. These studies showed that there are two types of interfacial breakdowns; one type that involves low temperature inclusions caused by excessive solute buildup and another involving high temperature inclusions which require two conditions to be met. These condition are: (1) significant compositional gradients in the melt and (2) an interface melt temperature near the peritectic decomposition temperature. Analysis of the experimental data lead to the hypothesis that fibers with the highest crystallinity are grown from SrO-rich 2212 melts. Evaluation of the constitutional supercooling responsible for the high temperature inclusions suggested that growth under these conditions was most vulnerable to disruption by HT inclusions. Tc increased with growth temperature for as-grown fibers. The concentration of SrO in the fibers had a parabolic relationship with temperature. The same parabolic relationship was observed between composition and Tc. The thermal history of 2212 crystals has been shown to influence their oxygen content which played a significant role in determining their Tc`s. Fiber heat treatment and the ambient gaseous atmosphere were found to dominate the Tc variations measured in this study.

  13. HEAT GENERATION

    DOEpatents

    Imhoff, D.H.; Harker, W.H.

    1963-12-01

    Heat is generated by the utilization of high energy neutrons produced as by nuclear reactions between hydrogen isotopes in a blanket zone containing lithium, a neutron moderator, and uranium and/or thorium effective to achieve multtplicatton of the high energy neutron. The rnultiplied and moderated neutrons produced react further with lithium-6 to produce tritium in the blanket. Thermal neutron fissionable materials are also produced and consumed in situ in the blanket zone. The heat produced by the aggregate of the various nuclear reactions is then withdrawn from the blanket zone to be used or otherwise disposed externally. (AEC)

  14. Heating affects the content and distribution profile of isoflavones in steamed black soybeans and black soybean koji.

    PubMed

    Huang, Ru-Yue; Chou, Cheng-Chun

    2008-09-24

    Steamed black soybeans and black soybean koji, a potentially functional food additive, were subjected to heating at 40-100 degrees C for 30 min. It was found that steamed black soybeans and black soybean koji after heating at 80 degrees C or higher generally showed reduced contents of malonylglucoside, acetylglucoside, and aglycone isoflavone and an increased content of beta-glucoside. A lower reduction in malonylglucoside and acetylglucoside isoflavone but greater reduction in aglycone content was noted in steamed black soybeans compared to black soybean koji after a similar heat treatment. After 30 min of heating at 100 degrees C, steamed black soybean retained ca. 90.3 and 83.8%, respectively, of its original malonylglucoside and acetylglucoside isoflavone, compared to lower residuals of 80.9 and 78.8%, respectively, for black soybean koji. In contrast, the heated black soybeans showed an aglycone residual of 68.0%, which is less than the 80.0% noted with the heated black soybean koji.

  15. Root-zone temperatures affect phenology of bud break, flower cluster development, shoot extension growth and gas exchange of 'Braeburn' (Malus domestica) apple trees.

    PubMed

    Greer, Dennis H; Wünsche, Jens N; Norling, Cara L; Wiggins, Harry N

    2006-01-01

    We investigated the effects of root-zone temperature on bud break, flowering, shoot growth and gas exchange of potted mature apple (Malus domestica (Borkh.)) trees with undisturbed roots. Soil respiration was also determined. Potted 'Braeburn' apple trees on M.9 rootstock were grown for 70 days in a constant day/night temperature regime (25/18 degrees C) and one of three constant root-zone temperatures (7, 15 and 25 degrees C). Both the proportion and timing of bud break were significantly enhanced as root-zone temperature increased. Rate of floral cluster opening was also markedly increased with increasing root-zone temperature. Shoot length increased but shoot girth growth declined as root-zone temperatures increased. Soil respiration and leaf photosynthesis generally increased as root-zone temperatures increased. Results indicate that apple trees growing in regions where root zone temperatures are < or = 15 degrees C have delayed bud break and up to 20% fewer clusters than apple trees exposed to root zone temperatures of > or = 15 degrees C. The effect of root-zone temperature on shoot performance may be mediated through the mobilization of root reserves, although the role of phytohormones cannot be discounted. Variation in leaf photosynthesis across the temperature treatments was inadequately explained by stomatal conductance. Given that root growth increases with increasing temperature, changes in sink activity induced by the root-zone temperature treatments provide a possible explanation for the non-stomatal effect on photosynthesis. Irrespective of underlying mechanisms, root-zone temperatures influence bud break and flowering in apple trees.

  16. The historical trend in float zone crystal diameters and power requirements for float zoned silicon crystals

    NASA Technical Reports Server (NTRS)

    Kramer, H. G.

    1981-01-01

    The power needed to zone silicon crystals by radio frequency heating was analyzed. The heat loss mechanisms are examined. Curves are presented for power as a function of crystal diameter for commercial silicon zoning.

  17. Exposure of Lactating Dairy Cows to Acute Pre-Ovulatory Heat Stress Affects Granulosa Cell-Specific Gene Expression Profiles in Dominant Follicles

    PubMed Central

    Vanselow, Jens; Vernunft, Andreas; Koczan, Dirk; Spitschak, Marion; Kuhla, Björn

    2016-01-01

    High environmental temperatures induce detrimental effects on various reproductive processes in cattle. According to the predicted global warming the number of days with unfavorable ambient temperatures will further increase. The objective of this study was to investigate effects of acute heat stress during the late pre-ovulatory phase on morphological, physiological and molecular parameters of dominant follicles in cycling cows during lactation. Eight German Holstein cows in established lactation were exposed to heat stress (28°C) or thermoneutral conditions (15°C) with pair-feeding for four days. After hormonal heat induction growth of the respective dominant follicles was monitored by ultrasonography for two days, then an ovulatory GnRH dose was given and follicular steroid hormones and granulosa cell-specific gene expression profiles were determined 23 hrs thereafter. The data showed that the pre-ovulatory growth of dominant follicles and the estradiol, but not the progesterone concentrations tended to be slightly affected. mRNA microarray and hierarchical cluster analysis revealed distinct expression profiles in granulosa cells derived from heat stressed compared to pair-fed animals. Among the 255 affected genes heatstress-, stress- or apoptosis associated genes were not present. But instead, we found up-regulation of genes essentially involved in G-protein coupled signaling pathways, extracellular matrix composition, and several members of the solute carrier family as well as up-regulation of FST encoding follistatin. In summary, the data of the present study show that acute pre-ovulatory heat stress can specifically alter gene expression profiles in granulosa cells, however without inducing stress related genes and pathways and suggestively can impair follicular growth due to affecting the activin-inhibin-follistatin system. PMID:27532452

  18. Study of space utilization and technical approaches to heating in buildings with irregular occupancy. Final report. Volume 1

    SciTech Connect

    Not Available

    1984-05-01

    The study objective was to review, identify and recommend technical approaches to the heating of buildings with irregular occupancy including physiological and psychological parameters affecting comfort. Numerous optimal room treatments have been identified for each space type and climate zone.

  19. Sub-lethal heat treatment affects the tolerance of Cronobacter sakazakii BCRC 13988 to various organic acids, simulated gastric juice and bile solution.

    PubMed

    Hsiao, Wan-Ling; Ho, Wei-Li; Chou, Cheng-Chun

    2010-12-15

    Cronobacter spp., formerly Enterobacter sakazakii, are considered emerging opportunistic pathogens and the etiological agent of life-threatening bacterial infections in infants. In the present study, C. sakazakii BCRC 13988 was first subjected to sub-lethal heat treatment at 47°C for 15min. Survival rates of the heat-shocked and non-shocked C. sakazakii cells in phosphate buffer solution (PBS, pH 4.0) containing organic acids (e.g. acetic, propionic, citric, lactic or tartaric acid), simulated gastric juice (pH 2.0-4.0), and bile solution (0.5 and 2.0%) were examined. Results revealed that sub-lethal heat treatment enhanced the test organism's tolerance to organic acids, although the extent of increased acid tolerance varied with the organic acid examined. Compared with the control cells, heat-shocked C. sakazakii cells after 120-min of exposure, exhibited the largest increase in tolerance in the lactic acid-containing PBS. Furthermore, although heat shock did not affect the behavior of C. sakazakii in bile solution, it increased the test organism's survival when exposed to simulated gastric juice with a pH of 3.0-4.0.

  20. Temperature trends in desert cities: how vegetation and urbanization affect the urban heat island dynamics in hyper-arid climates

    NASA Astrophysics Data System (ADS)

    Marpu, P. R.; Lazzarini, M.; Molini, A.; Ghedira, H.

    2013-12-01

    Urban areas represent a unique micro-climatic system, mainly characterized by scarcity of vegetation and ground moisture, an albedo strictly dependent on building materials and urban forms, high heat capacity, elevated pollutants emissions, anthropogenic heat production, and a characteristic boundary layer dynamics. For obvious historical reasons, the first to be addressed in the literature were the effects of urbanization on the local microclimate of temperate regions, where most of the urban development took place in the last centuries. Here micro-climatic characteristics all contribute to the warming of urban areas, also known as 'urban heat island' effect, and are expected to crucially impact future energy and water consumption, air quality, and human health. However, rapidly increasing urbanization rates in arid and hyper-arid developing countries could soon require more attention towards studying the effects of urban development on arid climates, which remained mainly unexplored till now. In this talk we investigate the climatology of urban heat islands in seven highly urbanized desert cities based on day and night temporal trends of land surface temperature (LST) and normalized difference vegetation index (NDVI) acquired using MODIS satellite during 2000-2012. Urban and rural areas are distinguished by analyzing the high-resolution temporal variability and averaged monthly values of LST, NDVI and Surface Urban Heat Island (SUHI) for all the seven cities and adjacent sub-urban areas. Different thermal behaviors were observed at the selected sites, also including temperature mitigation and inverse urban heat island, and are here discussed together with detailed analysis of the corresponding trends.

  1. Heat-denaturation and aggregation of quinoa (Chenopodium quinoa) globulins as affected by the pH value.

    PubMed

    Mäkinen, Outi E; Zannini, Emanuele; Koehler, Peter; Arendt, Elke K

    2016-04-01

    The influence of heating (100 °C; 0-15 min) on the relative molecular mass, protein unfolding and secondary structure of quinoa globulins was studied at pH 6.5 (low solubility), 8.5 and 10.5 (high solubility). The patterns of denaturation and aggregation varied with pH. Heating triggered the disruption of the disulfide bonds connecting the acidic and basic chains of the chenopodin subunits at pH 8.5 and 10.5, but not at pH 6.5. Large aggregates unable to enter a 4% SDS-PAGE gel were formed at pH 6.5 and 8.5, which became soluble under reducing conditions. Heating at pH 10.5 lead to a rapid dissociation of the native chenopodin and to the disruption of the subunits, but no SDS-insoluble aggregates were formed. No major changes in secondary structure occurred during a 15 min heating, but an increase in hydrophobicity indicated unfolding of the tertiary structure in all samples.

  2. Hair shedding score may affect body temperature more than hair coat color during heat stress in weaned beef heifers.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate the effect of hair shedding score and hair coat color on the vaginal temperature (VT) of calves during heat stress. Weaned Bos taurus beef heifers (n = 32; BW = 282 ± 6.4 kg) were assigned to a hair coat color class (BLACK; RED; or LIGHT, where LIGHT = yel...

  3. Antinutritional factors and functionality of protein-rich fractions of industrial guar meal as affected by heat processing.

    PubMed

    Nidhina, N; Muthukumar, S P

    2015-04-15

    Proximate composition analysis and antinutritional factor composition of different fractions of industrial guar meal: raw churi (IRC), heated churi (IHC), final churi (IFC) and guar korma (IGK) were studied and compared. Protein content was found to be very high in IGK (52.7%) when compared to the churi fractions (32-33%) and the trypsin inhibitor activities were found to be negligible in all the fractions (0.58-1.8 mg/g). Single fraction (IGK) was selected for further studies, based on the protein content. The antinutritional factors of selected fractions were significantly reduced by different heat treatments. Heat treatments significantly increased the water absorbing capacity of IGK, but reduced the nitrogen solubility, emulsifying and foaming capacity. Highest L(∗) value was observed for boiled IGK, highest a(∗) and b(∗) values for roasted IGK, during colour measurement. FTIR spectral analysis revealed the presence several aromatic groups in IGK and slight modifications in the molecular structure during heat treatments.

  4. Fluid processes in subduction zones.

    PubMed

    Peacock, S A

    1990-04-20

    Fluids play a critical role in subduction zones and arc magmatism. At shallow levels in subduction zones (<40 kilometers depth), expulsion of large volumes of pore waters and CH(4)-H(2)O fluids produced by diagenetic and low-grade metamorphic reactions affect the thermal and rheological evolution of the accretionary prism and provide nutrients for deep-sea biological communities. At greater depths, H(2)O and CO(2) released by metamorphic reactions in the subducting oceanic crust may alter the bulk composition in the overlying mantle wedge and trigger partial melting reactions. The location and conse-quences of fluid production in subduction zones can be constrained by consideration of phase diagrams for relevant bulk compositions in conjunction with fluid and rock pressure-temperature-time paths predicted by numerical heat-transfer models. Partial melting of subducting, amphibole-bearing oceanic crust is predicted only within several tens of million years of the initiation of subduction in young oceanic lithosphere. In cooler subduction zones, partial melting appears to occur primarily in the overlying mantle wedge as a result of fluid infiltration.

  5. Growth of high {Tc} superconducting fibers using a miniaturized laser-heated float zone process. Progress report, November 6, 1990--December 31, 1991

    SciTech Connect

    Feigelson, R.S.; Route, R.K.; DeMattei, R.C.

    1991-12-31

    This report summarizes the progress made on the project ``Growth of High {Tc} Superconducting Fibers Using a Miniaturized Laser-Heated Float Zone Process`` during the 14 month period from Nov. 6, 1990 to Dec. 31, 1991. The studies during this period focused primarily on phase diagram studies, phase relations in the calcium aluminate system and on Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} (BSCCO). Some work was also done on the Advanced Fiber Growing Station. Because of the complicated phase relationships found in the incongruently melting BSCCO system, the incongruently melting CA{sub 3}Al{sub 2}O{sub 6} phase of the calcium oxide-aluminum oxide system was studied as a model material. The data obtained was in agreement with well known solidification theory. Fibers grown from calcium oxide rich sources contained calcium oxide nodules which transported from the melting source interface to the growth interface, while those grown from aluminum oxide rich sources contained continuous inclusions of a divorced eutectic. The melt compositions were also found to follow theoretical predictions. The agreement of this data with the phase diagram and solidification theory demonstrates that phase equilibrium information can be extracted from fiber growth experiments. BSCCO feed rods were made from 12 different compositions. Fibers were grown from these rods and the melts were abruptly quenched which preserves the as-grown 2212 fiber, a glassy frozen melt and the source. A future study of these sections will reveal the phase relationships that exist in the BSCCO system. Melt temperature gradients of 500--1,000 C/cm were measured near the interface in these experiments. During this reporting period, work continued on the mechanical components of the Advanced Fiber Growth Station.

  6. Predicted optimum ambient temperatures for broiler chickens to dissipate metabolic heat do not affect performance or improve breast muscle quality

    PubMed Central

    Zahoor, I.; Mitchell, M.A.; Hall, S.; Beard, P.M.; Gous, R.M.; De Koning, D.J.; Hocking, P.M.

    2016-01-01

    Abstract An experiment was conducted to test the hypothesis that muscle damage in fast-growing broiler chickens is associated with an ambient temperature that does not permit the birds to lose metabolic heat resulting in physiological heat stress and a reduction in meat quality.The experiment was performed in 4 climate chambers and was repeated in 2 trials using a total of 200 male broiler chickens. Two treatments compared the recommended temperature profile and a cool regimen. The cool regimen was defined by a theoretical model that determined the environmental temperature that would enable heat generated by the bird to be lost to the environment.There were no differences in growth rate or feed intake between the two treatments. Breast muscles from birds on the recommended temperature regimen were lighter, less red and more yellow than those from the cool temperature regimen. There were no differences in moisture loss or shear strength but stiffness was greater in breast muscle from birds housed in the cool compared to the recommended regimen.Histopathological changes in the breast muscle were similar in both treatments and were characterised by mild to severe myofibre degeneration and necrosis with regeneration, fibrosis and adipocyte infiltration. There was no difference in plasma creatine kinase activity, a measure of muscle cell damage, between the two treatments consistent with the absence of differences in muscle pathology.It was concluded that breast muscle damage in fast-growing broiler chickens was not the result of an inability to lose metabolic heat at recommended ambient temperatures. The results suggest that muscle cell damage and breast meat quality concerns in modern broiler chickens are related to genetic selection for muscle yields and that genetic selection to address breast muscle integrity in a balanced breeding programme is imperative. PMID:26670305

  7. Predicted optimum ambient temperatures for broiler chickens to dissipate metabolic heat do not affect performance or improve breast muscle quality.

    PubMed

    Zahoor, I; Mitchell, M A; Hall, S; Beard, P M; Gous, R M; De Koning, D J; Hocking, P M

    2016-01-01

    An experiment was conducted to test the hypothesis that muscle damage in fast-growing broiler chickens is associated with an ambient temperature that does not permit the birds to lose metabolic heat resulting in physiological heat stress and a reduction in meat quality. The experiment was performed in 4 climate chambers and was repeated in 2 trials using a total of 200 male broiler chickens. Two treatments compared the recommended temperature profile and a cool regimen. The cool regimen was defined by a theoretical model that determined the environmental temperature that would enable heat generated by the bird to be lost to the environment. There were no differences in growth rate or feed intake between the two treatments. Breast muscles from birds on the recommended temperature regimen were lighter, less red and more yellow than those from the cool temperature regimen. There were no differences in moisture loss or shear strength but stiffness was greater in breast muscle from birds housed in the cool compared to the recommended regimen. Histopathological changes in the breast muscle were similar in both treatments and were characterised by mild to severe myofibre degeneration and necrosis with regeneration, fibrosis and adipocyte infiltration. There was no difference in plasma creatine kinase activity, a measure of muscle cell damage, between the two treatments consistent with the absence of differences in muscle pathology. It was concluded that breast muscle damage in fast-growing broiler chickens was not the result of an inability to lose metabolic heat at recommended ambient temperatures. The results suggest that muscle cell damage and breast meat quality concerns in modern broiler chickens are related to genetic selection for muscle yields and that genetic selection to address breast muscle integrity in a balanced breeding programme is imperative.

  8. Chlorophylls and carotenoids of kiwifruit puree are affected similarly or less by microwave than by conventional heat processing and storage.

    PubMed

    Benlloch-Tinoco, María; Kaulmann, Anouk; Corte-Real, Joana; Rodrigo, Dolores; Martínez-Navarrete, Nuria; Bohn, Torsten

    2015-11-15

    The impact of microwave (1000 W - 340 s) and conventional heat (97 °C - 30s) pasteurisation and storage (4, 10, 22 °C for up to 63 d) on total and individual carotenoids and chlorophylls in kiwifruit puree was evaluated. Bioaccessibility of carotenoids, before and after pasteurisation and storage, was also studied. Microwaves and conventional heating led to marked changes in the chlorophyll (42-100% losses) and carotenoid (62-91% losses) content. First- and second-order kinetics appropriately explained the degradation of total carotenoids and chlorophylls over time, respectively. Pasteurised samples showed significantly (p < 0.05) enhanced stability of these pigments, with microwaves (k = 0.007-0.031100 g mg(-1) day(-1) at 4-22 °C) promoting chlorophyll stability to a greater extent than conventional heating (k = 0.0015-0.034100 g mg(-1) day(-1) at 4-22 °C). Bioaccessibility of carotenoids remained (p < 0.05) unaffected by processing and storage. These results highlighted that the pigment composition of microwaved kiwifruit was more similar to that of the fresh fruit and better preserved during storage.

  9. Estrogen deprivation does not affect vascular heat shock response in female rats: a comparison with oxidative stress markers.

    PubMed

    Miragem, Antônio Azambuja; Ludwig, Mirna Stela; Heck, Thiago Gomes; Baldissera, Fernanda Giesel; dos Santos, Analu Bender; Frizzo, Matias Nunes; Homem de Bittencourt, Paulo Ivo

    2015-09-01

    Hot flashes, which involve a tiny rise in core temperature, are the most common complaint of peri- and post-menopausal women, being tightly related to decrease in estrogen levels. On the other hand, estradiol (E2) induces the expression of HSP72, a member of the 70 kDa family of heat shock proteins (HSP70), which are cytoprotective, cardioprotective, and heat inducible. Since HSP70 expression is compromised in age-related inflammatory diseases, we argued whether the capacity of triggering a robust heat shock (HS) response would be still present after E2 withdrawal. Hence, we studied the effects of HS treatment (hot tub) in female Wistar rats subjected to bilateral ovariectomy (OVX) after a 7-day washout period. Twelve h after HS, the animals were killed and aortic arches were surgically excised for molecular analyses. The results were compared with oxidative stress markers in the plasma (superoxide dismutase, catalase, and lipoperoxidation) because HSP70 expression is also sensitive to redox regulation. Extracellular (plasma) to intracellular HSP70 ratio, an index of systemic inflammatory status, was also investigated. The results showed that HS response was preserved in OVX animals, as inferred from HSP70 expression (up to 40% rise, p < 0.01) in the aortas, which was accompanied by no further alterations in oxidative stress, hematological parameters, and glycemic control either. This suggests that the lack of estrogen per se could not be solely ascribed as the unique source of low HSP70 expression as observed in long-term post-menopausal individuals. As a consequence, periodic evaluation of HSP70 status (iHSP70 vs. eHSP70) may be of clinical relevance because decreased HS response capacity is at the center of the onset of menopause-related dysfunctions.

  10. The thermal consequences of river-level variations in an urban groundwater body highly affected by groundwater heat pumps.

    PubMed

    García-Gil, Alejandro; Vázquez-Suñe, Enric; Schneider, Eduardo Garrido; Sánchez-Navarro, José Ángel; Mateo-Lázaro, Jesús

    2014-07-01

    The extensive implementation of ground source heat pumps in urban aquifers is an important issue related to groundwater quality and the future economic feasibility of existent geothermal installations. Although many cities are in the immediate vicinity of large rivers, little is known about the thermal river-groundwater interaction at a kilometric-scale. The aim of this work is to evaluate the thermal impact of river water recharges induced by flood events into an urban alluvial aquifer anthropogenically influenced by geothermal exploitations. The present thermal state of an urban aquifer at a regional scale, including 27 groundwater heat pump installations, has been evaluated. The thermal impacts of these installations in the aquifer together with the thermal impacts from "cold" winter floods have also been spatially and temporally evaluated to ensure better geothermal management of the aquifer. The results showed a variable direct thermal impact from 0 to 6 °C depending on the groundwater-surface water interaction along the river trajectory. The thermal plumes far away from the riverbed also present minor indirect thermal impacts due to hydraulic gradient variations.

  11. Neonatal capsaicin treatment in rats affects TRPV1-related noxious heat sensation and circadian body temperature rhythm.

    PubMed

    Jeong, Keun-Yeong; Seong, Jinsil

    2014-06-15

    The transient receptor potential vanilloid 1 (TRPV1) is a cation channel that serves as a polymodal detector of noxious stimuli such as capsaicin. Therefore, capsaicin treatment has been used to investigate the physiological function of TRPV1. Here, we report physiological changes induced by treating neonatal rats with capsaicin. Capsaicin (50mg/kg) (cap-treated) or vehicle (vehicle-treated) was systemically administered to newborn SD rat pups within 48 h after birth. TRPV1 expression, intake volume of capsaicin water, and noxious heat sensation were measured 6 weeks after capsaicin treatment. Circadian body temperature and locomotion were recorded by biotelemetry. Expression of Per1, Per2, Bmal1 and Hsf1 (clock genes) was also investigated. Neonatal capsaicin treatment not only decreased TRPV1 expression but also induced desensitization to noxious heat stimuli. Circadian body temperature of cap-treated rats increased significantly compared with that of vehicle-treated rats. Additionally, the amplitude of the circadian body temperature was reversed in cap-treated rats. Expression of the hypothalamic Hsf1 and liver Per2 clock genes followed a similar trend. Therefore, we suggest that these findings will be useful in studying various physiological mechanisms related to TRPV1.

  12. Digestibility and antigenicity of β-lactoglobulin as affected by heat, pH and applied shear.

    PubMed

    Rahaman, Toheder; Vasiljevic, Todor; Ramchandran, Lata

    2017-02-15

    Processing induced conformational changes can modulate digestibility of food allergens and thereby their antigenicity. Effect of different pH (3, 5, 7), temperature (room temperature, 120°C) and shear (0s(-1), 1000s(-1)) on simulated gastrointestinal digestibility of β-lg and post digestion antigenic characteristics have been studied. At all pH levels unheated β-lg showed resistance to peptic digestion with high antigenic value while it was fairly susceptible to pancreatin with moderate reduction in antigenicity. Heating at 120°C significantly improved both peptic and pancreatic digestion attributed to structural alterations that resulted in much lower antigenicity; the level of reduction being pH dependant. The lowest antigenicity was recorded at pH 5. Shearing (1000s(-1)) had a minor impact reducing digestibility and thereby enhancing antigenicity of unheated β-lg at pH 5 and 7 slightly; however in conjunction with heating (120°C) it reduced antigenicity further irrespective of the pH. Overall, treatment at pH 5, 120°C and 1000s(-1) could potentially reduce post digestion antigenicity of β-lg.

  13. Chromosomal rearrangements do not seem to affect the gene flow in hybrid zones between karyotypic races of the common shrew (Sorex araneus).

    PubMed

    Horn, Agnès; Basset, Patrick; Yannic, Glenn; Banaszek, Agata; Borodin, Pavel M; Bulatova, Nina S; Jadwiszczak, Katarzyna; Jones, Ross M; Polyakov, Andrei V; Ratkiewicz, Miroslaw; Searle, Jeremy B; Shchipanov, Nikolai A; Zima, Jan; Hausser, Jacques

    2012-03-01

    Chromosomal rearrangements are proposed to promote genetic differentiation between chromosomally differentiated taxa and therefore promote speciation. Due to their remarkable karyotypic polymorphism, the shrews of the Sorex araneus group were used to investigate the impact of chromosomal rearrangements on gene flow. Five intraspecific chromosomal hybrid zones characterized by different levels of karyotypic complexity were studied using 16 microsatellites markers. We observed low levels of genetic differentiation even in the hybrid zones with the highest karyotypic complexity. No evidence of restricted gene flow between differently rearranged chromosomes was observed. Contrary to what was observed at the interspecific level, the effect of chromosomal rearrangements on gene flow was undetectable within the S. araneus species.

  14. Safety Zones

    EPA Pesticide Factsheets

    These are established primarily to reduce the accidental spread of hazardous substances by workers or equipment from contaminated areas to clean areas. They include the exclusion (hot) zone, contamination reduction (warm) zone, and support (cold) zone.

  15. Phosphoglucose isomerase genotype affects running speed and heat shock protein expression after exposure to extreme temperatures in a montane willow beetle.

    PubMed

    Rank, Nathan E; Bruce, Douglas A; McMillan, David M; Barclay, Colleen; Dahlhoff, Elizabeth P

    2007-03-01

    Eastern Sierra Nevada populations of the willow beetle Chrysomela aeneicollis commonly experience stressfully high and low environmental temperatures that may influence survival and reproduction. Allele frequencies at the enzyme locus phosphoglucose isomerase (PGI) vary across a climatic latitudinal gradient in these populations, with PGI allele 1 being most common in cooler regions and PGI allele 4 in warmer ones. PGI genotypes differ in heat and cold tolerance and in expression of a 70 kDa heat shock protein. Here we examine genetic, behavioral and environmental factors affecting a performance character, running speed, for willow beetles, and assess effects of consecutive cold and heat exposure on running speed and expression of Hsp70 in the laboratory. In nature, running speed depends on air temperature and is higher for males than females. Mating beetles ran faster than single beetles, and differences among PGI genotypes in male running speed depended on the presence of females. In the laboratory, exposure to cold reduced subsequent running speed, but the amount of this reduction depended on PGI genotype and previous thermal history. Effects of exposure to heat also depended on life history stage and PGI genotype. Adults possessing allele 1 ran fastest after a single exposure to stressful temperature, whereas those possessing allele 4 ran faster after repeated exposure. Larvae possessing allele 4 ran fastest after a single stressful exposure, but running speed generally declined after a second exposure to stressful temperature. The ranking of PGI genotypes after the second exposure depended on whether a larva had been exposed to cold or heat. Effects of temperature on Hsp70 expression also varied among PGI genotypes and depended on type of exposure, especially for adults (single heat exposure, two cold exposures: PGI 1-1>1-4>4-4; other multiple extreme exposures: 4-4>1-4>1-1). There was no consistent association between alleles at other polymorphic enzyme loci

  16. Calculating in situ density and heat capacity of rocks with GMIN: new type of input data for thermomechanical modeling of subduction zones

    NASA Astrophysics Data System (ADS)

    Burchard, M.; Gerya, T.

    2003-04-01

    The technique of minimizing the Gibbs free energy of specified rock compositions by varying the amounts and compositions of coexisting phases has provided new insights and possibilities for petrological investigations. For thermomechanical modeling of subduction zone processes density, isobaric heat capacity, thermal expansion and compressibility can then be extracted as a function of the amounts and compositions of coexisting phases [1]. At present two programs offer the possibility of calculating phase diagrams with this technique, Holland and Powell's Thermocalc [2] and De Capitani's Theriac/Domino [3] package. The first one is a command line program producing a text output which can be converted to graphics with a user-written MathematicaTM program. It uses the Holland and Powell data base [2]. De Capitani's program is distributed as a Fortran 77 source code and uses the Berman database. Neither of these programs offers interfaces for use with geodynamic modeling programs. We have therefore enhanced our new Gibbs minimization program GMin [4] with an interface able to transfer density, entahalpy and volume values into databases or other programs. The minimization algorithm of our program is based on the de Capitani method [3], modified and adapted for the Holland and Powell database [2]. To achieve rapid convergence and stability of minimization we have optimized the computing strategy for models of solid solutions used in [2]. The standard program is divided in two parts, a front end and a calculation program controlled by the front end program. This construction opens the possibility of starting up several calculations in parallel on different computers and different operating systems. In this way large numbers of calculations can be performed on normal PC-networks (servers and clients) controlled by only one front end program. The front end is able to create pressure and temperature ordered databases containing density, enthalpy, volume and composition which

  17. Impact of western Siberia heat wave 2012 on greenhouse gases and trace metal concentration in thaw lakes of discontinuous permafrost zone

    NASA Astrophysics Data System (ADS)

    Pokrovsky, O. S.; Shirokova, L. S.; Kirpotin, S. N.; Kulizhsky, S. P.; Vorobiev, S. N.

    2013-08-01

    During the anomalously hot summer in 2012, surface air temperatures in Western Siberia were 5 to 15 °C higher than those observed during the previous period of > 30 yr. This unusual climate phenomenon provided an opportunity to examine the effects of short-term natural heating of water in thermokarst ponds and lakes in discontinuous permafrost zones and compare these observations to previous field results obtained when the temperature was normal during the summer of 2010 in the same region. In 2012, thermokarst bodies of water shrank significantly, water levels dropped approximately 50 cm in large lakes and small (< 10-100 m2) ponds, and shallow soil depressions disappeared. Based on samples from ~ 40 bodies of water collected previously and in 2012, first-order features of changes in chemical composition in response to increased water temperatures (from 14.1 ± 2.2 to 23.8 ± 2.3 °C in 2010 and 2012, respectively) were established. In these thermokarst bodies of water that covered a full range of surface areas, the average conductivity and pH were almost unchanged, whereas dissolved organic carbon (DOC), Cl- and SO42- concentrations were higher by a factor of ~ 2 during summer 2012 compared to periods with normal temperatures. Similarly, most divalent metals and insoluble trivalent and tetravalent elements were more concentrated by a factor of 1.7-2.4 in the summer of 2012 than normal periods. The average concentrations of dissolved CO2 and CH4 during the hot summer of 2012 increased by factors of 1.4 and 4.9, respectively. For most of the trace elements bound to colloids, the degree of colloidal binding decreased by a factor of 1.44 ± 0.33 (for an average of 40 elements) during the hot summer of 2012 compared to normal periods. Increases in CO2 and CH4 concentrations with the decreasing size of the body of water were well-pronounced during the hot summer of 2012. The concentrations of CO2 and CH4 rose by factors of 5 and 150, respectively, in small (≤ 102 m2

  18. Pioneering Heat Pump Project

    SciTech Connect

    Aschliman, Dave; Lubbehusen, Mike

    2015-06-30

    This project was initiated at a time when ground coupled heat pump systems in this region were limited in size and quantity. There were economic pressures with costs for natural gas and electric utilities that had many organizations considering ground coupled heat pumps; The research has added to the understanding of how ground temperatures fluctuate seasonally and how this affects the performance and operation of the heat pumps. This was done by using a series of temperature sensors buried within the middle of one of the vertical bore fields with sensors located at various depths below grade. Trending of the data showed that there is a lag in ground temperature with respect to air temperatures in the shoulder months, however as full cooling and heating season arrives, the heat rejection and heat extraction from the ground has a significant effect on the ground temps; Additionally it is better understood that while a large community geothermal bore field serving multiple buildings does provide a convenient central plant to use, it introduces complexity of not being able to easily model and predict how each building will contribute to the loads in real time. Additional controllers and programming were added to provide more insight into this real time load profile and allow for intelligent shedding of load via a dry cooler during cool nights in lieu of rejecting to the ground loop. This serves as a means to ‘condition’ the ground loop and mitigate thermal creep of the field, as is typically observed; and It has been observed when compared to traditional heating and cooling equipment, there is still a cost premium to use ground source heat pumps that is driven mostly by the cost for vertical bore holes. Horizontal loop systems are less costly to install, but do not perform as well in this climate zone for heating mode

  19. Strength of stick-slip and creeping subduction megathrusts from heat flow observations.

    PubMed

    Gao, Xiang; Wang, Kelin

    2014-08-29

    Subduction faults, called megathrusts, can generate large and hazardous earthquakes. The mode of slip and seismicity of a megathrust is controlled by the structural complexity of the fault zone. However, the relative strength of a megathrust based on the mode of slip is far from clear. The fault strength affects surface heat flow by frictional heating during slip. We model heat-flow data for a number of subduction zones to determine the fault strength. We find that smooth megathrusts that produce great earthquakes tend to be weaker and therefore dissipate less heat than geometrically rough megathrusts that slip mainly by creeping.

  20. Decontamination method using heat and relative humidity for radish seeds achieves a 7-log reduction of Escherichia coli O157:H7 without affecting product quality.

    PubMed

    Kim, Y B; Kim, H W; Song, M K; Rhee, M S

    2015-05-18

    We developed a novel decontamination method to inactivate Escherichia coli O157:H7 on radish seeds without adversely affecting seed germination or product quality. The use of heat (55, 60, and 65 °C) combined with relative humidity (RH; 25, 45, 65, 85, and 100%) for 24h was evaluated for effective microbial reduction and preservation of seed germination rates. A significant two-way interaction of heat and RH was observed for both microbial reduction and germination rate (P<0.0001). Increases in heat and RH were associated with corresponding reductions in E. coli O157:H7 and in germination rate (P<0.05). The order of lethality for the different treatments was generally as follows: no treatment <55 °C/25-65% RH ≒60 °C/25-45% RH ≒65 °C/25% RH <55 °C/85% RH =60 °C/65% RH <55 °C/100% RH =60 °C/85-100% RH =65 °C/45-100% RH. The most effective condition, 65 °C/45% RH, completely inactivated E. coli O157:H7 on the seeds (7.0 log CFU/g reduction) and had no significant effect on the germination rate (85.4%; P>0.05) or product quality. The method uses only heat and relative humidity without chemicals, and is thus applicable as a general decontamination procedure in spout producing plants where the use of growth chambers is the norm.

  1. Off-flavor related volatiles in soymilk as affected by soybean variety, grinding, and heat-processing methods.

    PubMed

    Zhang, Yan; Guo, Shuntang; Liu, Zhisheng; Chang, Sam K C

    2012-08-01

    Off-flavor of soymilk is a barrier to the acceptance of consumers. The objectionable soy odor can be reduced through inhibition of their formation or through removal after being formed. In this study, soymilk was prepared by three grinding methods (ambient, cold, and hot grinding) from two varieties (yellow Prosoy and a black soybean) before undergoing three heating processes: stove cooking, one-phase UHT (ultrahigh temperature), and two-phase UHT process using a Microthermics direct injection processor, which was equipped with a vacuuming step to remove injected water and volatiles. Eight typical soy odor compounds, generated from lipid oxidation, were extracted by a solid-phase microextraction method and analyzed by gas chromatography. The results showed that hot grinding and cold grinding significantly reduced off-flavor as compared with ambient grinding, and hot grinding achieved the best result. The UHT methods, especially the two-phase UHT method, were effective to reduce soy odor. Different odor compounds showed distinct concentration patterns because of different formation mechanisms. The two varieties behaved differently in odor formation during the soymilk-making process. Most odor compounds could be reduced to below the detection limit through a combination of hot grinding and two-phase UHT processing. However, hot grinding gave lower solid and protein recoveries in soymilk.

  2. ANALYSIS OF FACTORS AFFECTING OUTCOME OF ULTRASOUND-GUIDED RADIOFREQUENCY HEAT ABLATION FOR TREATMENT OF PRIMARY HYPERPARATHYROIDISM IN DOGS.

    PubMed

    Bucy, Daniel; Pollard, Rachel; Nelson, Richard

    2017-01-01

    Radiofrequency (RF) parathyroid ablation is a noninvasive treatment for hyperparathyroidism in dogs. There are no published data assessing factors associated with RF parathyroid ablation success or failure in order to guide patient selection and improve outcome. The purpose of this retrospective analytical study was to determine whether imaging findings, biochemical data, or concurrent diseases were associated with RF heat ablation treatment failure. For inclusion in the study, dogs must have had a clinical diagnosis of primary hyperparathyroidism, undergone cervical ultrasound and RF ablation of abnormal parathyroid tissue, and must have had at least 3 months of follow-up information available following the date of ultrasound-guided parathyroid ablation. Dogs were grouped based on those with recurrent or persistent hypercalcemia and those without recurrent or persistent hypercalcemia following therapy. Parathyroid nodule size, thyroid lobe size, nodule location, and presence of concurrent disease were recorded. Recurrence of hypercalcemia occurred in 9/32 dogs that had ablation of abnormal parathyroid tissue (28%) and one patient had persistent hypercalcemia (3%) following parathyroid ablation. Nodule width (P = 0.036), height (P = 0.028), and largest cross-sectional area (P = 0.023) were larger in dogs that had recurrent or persistent hypercalcemia following ablation. Hypothyroidism was more common in dogs with recurrent disease (P = 0.044). Radiofrequency ablation was successful in 22/32 (69%) dogs. Larger parathyroid nodule size and/or concurrent hypothyroidism were associated with treatment failure in dogs that underwent ultrasound-guided RF parathyroid nodule ablation.

  3. ELECTRON HEATING IN MAGNETOROTATIONAL INSTABILITY: IMPLICATIONS FOR TURBULENCE STRENGTH IN THE OUTER REGIONS OF PROTOPLANETARY DISKS

    SciTech Connect

    Mori, Shoji; Okuzumi, Satoshi

    2016-01-20

    The magnetorotational instability (MRI) drives vigorous turbulence in a region of protoplanetary disks where the ionization fraction is sufficiently high. It has recently been shown that the electric field induced by the MRI can heat up electrons and thereby affect the ionization balance in the gas. In particular, in a disk where abundant dust grains are present, the electron heating causes a reduction of the electron abundance, thereby preventing further growth of the MRI. By using the nonlinear Ohm's law that takes into account electron heating, we investigate where in protoplanetary disks this negative feedback between the MRI and ionization chemistry becomes important. We find that the “e-heating zone,” the region where the electron heating limits the saturation of the MRI, extends out up to 80 AU in the minimum-mass solar nebula with abundant submicron-sized grains. This region is considerably larger than the conventional dead zone whose radial extent is ∼20 AU in the same disk model. Scaling arguments show that the MRI turbulence in the e-heating zone should have a significantly lower saturation level. Submicron-sized grains in the e-heating zone are so negatively charged that their collisional growth is unlikely to occur. Our present model neglects ambipolar and Hall diffusion, but our estimate shows that ambipolar diffusion would also affect the MRI in the e-heating zone.

  4. Electron Heating in Magnetorotational Instability: Implications for Turbulence Strength in the Outer Regions of Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Mori, Shoji; Okuzumi, Satoshi

    2016-01-01

    The magnetorotational instability (MRI) drives vigorous turbulence in a region of protoplanetary disks where the ionization fraction is sufficiently high. It has recently been shown that the electric field induced by the MRI can heat up electrons and thereby affect the ionization balance in the gas. In particular, in a disk where abundant dust grains are present, the electron heating causes a reduction of the electron abundance, thereby preventing further growth of the MRI. By using the nonlinear Ohm's law that takes into account electron heating, we investigate where in protoplanetary disks this negative feedback between the MRI and ionization chemistry becomes important. We find that the “e-heating zone,” the region where the electron heating limits the saturation of the MRI, extends out up to 80 AU in the minimum-mass solar nebula with abundant submicron-sized grains. This region is considerably larger than the conventional dead zone whose radial extent is ∼20 AU in the same disk model. Scaling arguments show that the MRI turbulence in the e-heating zone should have a significantly lower saturation level. Submicron-sized grains in the e-heating zone are so negatively charged that their collisional growth is unlikely to occur. Our present model neglects ambipolar and Hall diffusion, but our estimate shows that ambipolar diffusion would also affect the MRI in the e-heating zone.

  5. A reduced core to skin temperature gradient, not a critical core temperature, affects aerobic capacity in the heat.

    PubMed

    Cuddy, John S; Hailes, Walter S; Ruby, Brent C

    2014-07-01

    The purpose of this study was to determine the impact of the core to skin temperature gradient during incremental running to volitional fatigue across varying environmental conditions. A secondary aim was to determine if a "critical" core temperature would dictate volitional fatigue during running in the heat. 60 participants (n=49 male, n=11 female; 24±5 yrs, 177±11 cm, 75±13 kg) completed the study. Participants were uniformly stratified into a specific exercise temperature group (18 °C, 26 °C, 34 °C, or 42 °C) based on a 3-mile run performance. Participants were equipped with core and chest skin temperature sensors and a heart rate monitor, entered an environmental chamber (18 °C, 26 °C, 34 °C, or 42 °C), and rested in the seated position for 10 min before performing a walk/run to volitional exhaustion. Initial treadmill speed was 3.2 km h(-1) with a 0% grade. Every 3 min, starting with speed, speed and grade increased in an alternating pattern (speed increased by 0.805 km h(-1), grade increased by 0.5%). Time to volitional fatigue was longer for the 18 °C and 26 °C group compared to the 42 °C group, (58.1±9.3 and 62.6±6.5 min vs. 51.3±8.3 min, respectively, p<0.05). At the half-way point and finish, the core to skin gradient for the 18 °C and 26 °C groups was larger compared to 42 °C group (halfway: 2.6±0.7 and 2.0±0.6 vs. 1.3±0.5 for the 18 °C, 26 °C and 42 °C groups, respectively; finish: 3.3±0.7 and 3.5±1.1 vs. 2.1±0.9 for the 26 °C, 34 °C, and 42 °C groups, respectively, p<0.05). Sweat rate was lower in the 18 °C group compared to the 26 °C, 34 °C, and 42 °C groups, 3.6±1.3 vs. 7.2±3.0, 7.1±2.0, and 7.6±1.7 g m(-2) min(-1), respectively, p<0.05. There were no group differences in core temperature and heart rate response during the exercise trials. The current data demonstrate a 13% and 22% longer run time to exhaustion for the 18 °C and 26 °C group, respectively, compared to the 42 °C group despite no differences

  6. Regulation of lead toxicity by heat shock protein 90 (daf-21) is affected by temperature in Caenorhabditis elegans.

    PubMed

    Wang, Yunbiao; Xu, Songbai; Liu, Jing; Zhang, Yanhui; Guo, Tai L

    2014-06-01

    In the nematode Caenorhabditis elegans, stress resistance can be regulated by dauer formation (daf) genes. In the present study, regulation of heavy metal lead (Pb) toxicity by the 90-kDa heat shock proteins (Hsp90; daf-21) was investigated in both wild-type C. elegans and daf-21/Hsp90 mutants by focusing on the effects of varied temperatures below (15°C) or above (25 and 30°C) the presumptive optimum growth temperature (20°C). More acute toxicity of Pb, indicated by the 24-h median lethal concentrations (LC50), was observed in wild-type adults than in the daf-21 mutant adults at 15, 20 and 25°C; however, the daf-21 mutant adults showed more sensitivity at 30°C. Enhanced Pb sensitivity (e.g., decrease LC50) in both types of C. elegans was observed with both increased and decreased temperatures when compared to that at 20°C. Additional examined endpoints included time course of toxicity at LC50s, pharyngeal pumping, reproduction, life span, and Hsp90 expression. Collective results showed that temperatures both above and below 20°C exacerbated Pb toxicity, and that the protein level of daf-21/Hsp90 was one of the most sensitive indicators of Pb toxicity in wild-type C. elegans, while pharyngeal pumping was more Pb sensitive in daf-21 mutants. Therefore, the expression of daf-21/Hsp90 has apparent utility for the prediction and assessment of Pb-induced toxicity in nematodes. Further, the stress responses related to Hsp90 expression in C. elegans may have considerable potential as sensitive biomarkers for the monitoring of environmental Pb contamination.

  7. Investigation of factors affecting hypothermic pelvic tissue cooling using bio-heat simulation based on MRI-segmented anatomic models

    PubMed Central

    Lin, Yuting; Lin, Wei-Ching; Fwu, Peter T.; Shih, Tzu-Ching; Yeh, Lee-Ren; Su, Min-Ying; Chen, Jeon-Hor

    2015-01-01

    This study applied a simulation method to map the temperature distribution based on magnetic resonance imaging (MRI) of individual patients, and investigated the influence of different pelvic tissue types as well as the choice of thermal property parameters on the efficiency of endorectal cooling balloon (ECB). MR images of four subjects with different prostate sizes and pelvic tissue compositions, including fatty tissue and venous plexus, were analyzed. The MR images acquired using endorectal coil provided a realistic geometry of deformed prostate that resembled the anatomy in the presence of ECB. A single slice with the largest two-dimensional (2D) cross-sectional area of the prostate gland was selected for analysis. The rectal wall, prostate gland, peri-rectal fatty tissue, peri-prostatic fatty tissue, peri-prostatic venous plexus, and urinary bladder were manually segmented. Pennes’ bioheat thermal model was used to simulate the temperature distribution dynamics, by using an in-house finite element mesh based solver written in Matlab. The results showed that prostate size and periprostatic venous plexus were two major factors affecting ECB cooling efficiency. For cases with negligible amount of venous plexus and small prostate, the averaged temperature in the prostate and neurovascular bundles could be cooled down to 25°C within 30 minutes. For cases with abundant venous plexus and large prostate, the temperature could not reach 25°C at the end of 3 hours cooling. Large prostate made the cooling difficult to propagate through. The impact of fatty tissue on cooling effect was small. The filling of bladder with warm urine during the ECB cooling procedure did not affect the temperature in the prostate or NVB. In addition to the 2D simulation, in one case a 3D pelvic model was constructed for volumetric simulation. It was found that the 2D slice with the largest cross-sectional area of prostate had the most abundant venous plexus, and was the most difficult

  8. Did the London Initiative Zone investment programme affect general practice structure and performance in East London? A time series analysis of cervical screening coverage and asthma prescribing.

    PubMed

    Naish, J; Eldridge, S; Moser, K; Sturdy, P

    2002-11-01

    A programme of incentives was set up in the London Initiative Zones to improve primary care in inner London based on the findings of the Tomlinson Enquiry in 1992. This descriptive study is a 4-y time series analysis of changes in general practice structure in East London as the result of London Initiative Zone investment, and an exploration of the possible effect of investment on practice performance. We used routinely available administrative data for the whole analysis. General practice characteristics and two selected performance indicators: the asthma prophylaxis to bronchodilator ratio and cervical cytology screening rate, for all practices in the East London and the City Health Authority for 4 y, 1993-1996, were used. Both reflect practice efficiency, but relate to different aspects of practice performance. The prescribing indicator is more indicative of the quality of clinical practise, whereas cervical screening coverage relates more to the characteristics of the practice population and to practice organisation. Repeated measures analyses were used to identify trends and to explore the relationship between changes in practice characteristics and performance. Graphical methods were used to compare East London trends with the rest of England. There were significant improvements in practice structure as the consequence of London Initiative Zone investment. There was a positive association with improvements in practice performance, but East London still lagged some way behind national patterns. The findings suggest that while improvements in asthma prescribing follow the national trend, practices have difficulty in achieving and sustaining the 80% target for cervical cytology screening, and that an overall population coverage of 80% may be in doubt.Increased investment in practice staffing may be influential in improving some aspects of performance. However, in common with other inner cities, a greater effort and more innovative strategies may be needed to

  9. Coarsening Behavior of the (Ti, Nb)(C, N) Complex Particle in a Microalloyed Steel Weld Heat-Affected Zone Considering the Critical Particle Size

    NASA Astrophysics Data System (ADS)

    Moon, Joonoh; Kim, Sanghoon; Lee, Jongbong; Lee, Changhee

    2007-11-01

    Our recent report revealed the effect of critical particle size on the particle coarsening behavior of the TiN particle. In the present work, the equation for critical particle size is extended by considering the change of particle volume fraction during the continuous thermal cycle. By considering the concept of modified critical particle size, coarsening of the (Ti, Nb)(C, N) complex particle is calculated, and the calculated results are in good agreement with experimental data.

  10. Beyond the classic thermoneutral zone

    PubMed Central

    Kingma, Boris RM; Frijns, Arjan JH; Schellen, Lisje; van Marken Lichtenbelt, Wouter D

    2014-01-01

    The thermoneutral zone is defined as the range of ambient temperatures where the body can maintain its core temperature solely through regulating dry heat loss, i.e., skin blood flow. A living body can only maintain its core temperature when heat production and heat loss are balanced. That means that heat transport from body core to skin must equal heat transport from skin to the environment. This study focuses on what combinations of core and skin temperature satisfy the biophysical requirements of being in the thermoneutral zone for humans. Moreover, consequences are considered of changes in insulation and adding restrictions such as thermal comfort (i.e. driver for thermal behavior). A biophysical model was developed that calculates heat transport within a body, taking into account metabolic heat production, tissue insulation, and heat distribution by blood flow and equates that to heat loss to the environment, considering skin temperature, ambient temperature and other physical parameters. The biophysical analysis shows that the steady-state ambient temperature range associated with the thermoneutral zone does not guarantee that the body is in thermal balance at basal metabolic rate per se. Instead, depending on the combination of core temperature, mean skin temperature and ambient temperature, the body may require significant increases in heat production or heat loss to maintain stable core temperature. Therefore, the definition of the thermoneutral zone might need to be reformulated. Furthermore, after adding restrictions on skin temperature for thermal comfort, the ambient temperature range associated with thermal comfort is smaller than the thermoneutral zone. This, assuming animals seek thermal comfort, suggests that thermal behavior may be initiated already before the boundaries of the thermoneutral zone are reached. PMID:27583296

  11. 24 CFR 3280.506 - Heat loss/heat gain.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... §§ 3280.508 and 3280.509. The Uo (Coefficient of heat transmission) value zone for which the manufactured... zone shall be determined from the map in figure 506. EC17OC91.005 (a) Coefficient of heat transmission. The overall coefficient of heat transmission (Uo) of the manufactured home for the respective...

  12. 24 CFR 3280.506 - Heat loss/heat gain.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... §§ 3280.508 and 3280.509. The Uo (Coefficient of heat transmission) value zone for which the manufactured... zone shall be determined from the map in figure 506. EC17OC91.005 (a) Coefficient of heat transmission. The overall coefficient of heat transmission (Uo) of the manufactured home for the respective...

  13. Modeling of Heat and Mass Transfer in Fusion Welding

    SciTech Connect

    Zhang, Wei

    2011-01-01

    In fusion welding, parts are joined together by melting and subsequent solidification. Although this principle is simple, complex transport phenomena take place during fusion welding, and they determine the final weld quality and performance. The heat and mass transfer in the weld pool directly affect the size and shape of the pool, the solidification microstructure, the formation of weld defects such as porosity and humping, and the temperature distribution in the fusion zone and heat-affected zone (HAZ). Furthermore, the temperature evolution affects the kinetics and extent of various solid-state phase transformations, which in turn determine the final weld microstructure and mechanical properties. The formation of residual stresses and distortion originates from the thermal expansion and contraction during welding heating and cooling, respectively.

  14. Air Source Cold Climate Heat Pump

    DTIC Science & Technology

    2013-08-01

    The buildings were modified so that one zone used the cold climate heat pump and the other zone used its original modern central HVAC system . Both...been updated with insulation, a sheet metal roof, and a modern central HVAC system . Both buildings had two zones for heating and cooling, which...climate heat pump and the other zone used its original modern central HVAC system . Both zones were instrumented so that energy consumption and

  15. The Intertropical Convergence Zone

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Intertropical Convergence Zone, or ITCZ, is the region that circles the Earth, near the equator, where the trade winds of the Northern and Southern Hemispheres come together. The intense sun and warm water of the equator heats the air in the ITCZ, raising its humidity and causing it to rise. As the air rises it cools, releasing the accumulated moisture in an almost perpetual series of thunderstorms. Variation in the location of the ITCZ drastically affects rainfall in many equatorial nations, resulting in the wet and dry seasons of the tropics rather than the cold and warm seasons of higher latitudes. Longer term changes in the ITCZ can result in severe droughts or flooding in nearby areas. This image is a combination of cloud data from NOAA's newest Geostationary Operational Environmental Satellite (GOES-11) and color land cover classification data. The ITCZ is the band of bright white clouds that cuts across the center of the image. For more GOES images, visit the GOES Project Science site. Image Courtesy GOES Project Science Office

  16. Effect of Post-Weld Heat Treatment on Creep Rupture Properties of Grade 91 Steel Heavy Section Welds

    SciTech Connect

    Li, Leijun

    2012-11-02

    This project will conduct a systematic metallurgical study on the effect of post-weld heat treatment (PWHT) on the creep rupture properties of P91 heavy section welds. The objective is to develop a technical guide for selecting PWHT parameters, and to predict expected creep-rupture life based on the selection of heat treatment parameters. The project consists of four interdependent tasks: Experimentally and numerically characterize the temperature fields of typical post-weld heat treatment procedures for various weld and joint configurations to be used in Gen IV systems. Characterize the microstructure of various regions, including the weld fusion zone, coarse-grain heat-affected zone, and fine-grain heat affected zone, in the welds that underwent the various welding and PWHT thermal histories. Conduct creep and creep-rupture testing of coupons extracted from actual and physically simulated welds. Establish the relationship among PWHT parameters, thermal histories, microstructure, creep, and creep-rupture properties.

  17. Physicochemical characteristics of the hyporheic zone affect redd site selection of chum salmon and fall chinook salmon in the Columbia River

    SciTech Connect

    Geist, David R. ); Hanrahan, Timothy P. ); Arntzen, Evan V. ); McMichael, Geoffrey A. ); Murray, Christopher J. ); Chien, Yi-Ju )

    2002-11-01

    Chum salmon Oncorhynchus keta and fall chinook salmon O. tshawytscha spawned at different locations in the vicinity of Ives Island, Washington, a side channel to the Columbia River downstream of Bonneville Dam. We hypothesized that measurements of water depth, substrate size, and water velocity alone would not explain the separation in spawning areas and began a 2-year investigation of physicochemical characteristics of the hyporheic zone. We found that chum salmon spawned in upwelling water that was significantly warmer than the surrounding river water. In contrast, fall chinook salmon constructed redds at downwelling sites where there was no difference in temperature between the river and its bed. Understanding the specific features that are important for chum salmon and fall chinook salmon redd site selection at Ives Island will be useful to resource managers attempting to maximize available spawning habitat for these species within the constraints imposed by other water resource needs.

  18. Marginal zone lymphoma of mucosa-associated lymphoid tissue with prominent plasma cell differentiation affecting the palatine tonsil: histopathological and immunohistochemical analysis.

    PubMed

    Carlos Bregni, Román; Nuyens, Michel; Vassallo, José; Soares, Fernando Augusto; Romañach, Mário José; León, Jorge Esquiche; Almeida, Oslei Paes

    2012-04-01

    Non-Hodgkin lymphomas (NHLs) of the oral cavity and oropharynx constitute 13% of all primary extranodal NHLs. Marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) in the palatine tonsil is rare, corresponding to 6% of the NHLs of the Waldeyer ring. Some cases of MALT lymphoma can present prominent plasma cell differentiation, and less commonly, monoclonal gammopathy. The differential diagnosis of these cases from other NHLs with plasmacytic differentiation or plasma cell neoplasms is very difficult. In this article, we describe a rare case of MALT lymphoma in a 34-year-old man presenting as a swelling of the palatine tonsil. The tumor mass was diagnosed as MALT lymphoma with prominent plasma cell differentiation. Systemic evaluation was noncontributory. This is the first report of MALT lymphoma showing extensive plasmacytic differentiation of the palatine tonsil, and reinforces a possible relationship between extramedullary plasmacytoma and MALT lymphoma.

  19. Microgravity silicon zoning investigation

    NASA Technical Reports Server (NTRS)

    Kern, E. L.; Gill, G. L., Jr.

    1985-01-01

    The flow instabilities in floating zones of silicon were investigated and methods for investigation of these instabilities in microgravity were defined. Three principal tasks were involved: (1) characterization of the float zone in small diameter rods; (2) investigation of melt flow instabilities in circular melts in silicon disks; and (3) the development of a prototype of an apparatus that could be used in near term space experiments to investigate flow instabilities in a molten zone. It is shown that in a resistance heated zoner with 4 to 7 mm diameter silicon rods that the critical Marangoni number is about 1480 compared to a predicted value of 14 indicative that viable space experiments might be performed. The prototype float zone apparatus is built and specifications are prepared for a flight zoner should a decision be reached to proceed with a space flight experimental investigation.

  20. Factors affecting the incidence of postpartum oestrus, ovarian activity and reproductive performance in Thoroughbred mares bred at foal heat under Indian subtropical conditions.

    PubMed

    Sharma, Sumeet; Davies Morel, M C G; Dhaliwal, G S

    2010-07-01

    Decreased reproductive performance due to summer stress is a well known phenomenon in farm livestock. Whether this occurs in the mare and specifically how this might affect postpartum reproductive activity and performance, especially at Foal Heat (FH), is unknown. This study, therefore, aims to investigate this and the factors that might affect postpartum reproductive activity. Reproductive records of 228 Thoroughbred mares (694 mare years) bred in subtropical north-western India were retrospectively analysed. Overt oestrous activity occurred within 21 d postpartum in 92.94% (645/694) of mares. Significantly (p<0.001) more April foaling mares (97.37%, 185/190) expressed postpartum oestrous activity than those foaling in January (83.61%; 51/61) and February (88.49; 123/139). Similarly significantly (p<0.01) fewer multiparous mares failed to demonstrate oestrous activity than primiparous mares (6.12% vs.15.07%; 38/621 vs. 11/73, respectively). 190 of these 694 mares were additionally monitored to confirm ovulation; in these mares onset of FH (oestrus plus confirmed ovulation) occurred 8.42+/-0.17 d and first ovulation 13.64+/-0.20 d postpartum. Month, stud farm, year, and parity did not affect interval from parturition to FH onset or to first ovulation; or FH onset to ovulation. In FH bred mares Day 16 pregnancy rate and overall foaling rate were 53.76% (100/186) and 46.24% (86/186) respectively and were similar to those of mares bred later postpartum. FH pregnancy rates were not affected by stud, season, month, year, number of matings, or day of ovulation but were significantly (p<0.008) lowered by increasing mare age. Significantly (p<0.01) lower Day 16 pregnancy rates were observed in uterine treated mares compared to untreated mares (31.09% vs. 57.96%; 9/29 vs. 91/157, respectively), this difference was not evident during the rest of pregnancy. In conclusion, postpartum reproductive and ovarian activity appears to be affected by environment, i.e., delayed in

  1. How selection for reproduction or foundation for longevity could have affected blood lymphocyte populations of rabbit does under conventional and heat stress conditions.

    PubMed

    Ferrian, Selena; Guerrero, Irene; Blas, Enrique; García-Diego, Fernando J; Viana, David; Pascual, Juan J; Corpa, Juan M

    2012-11-15

    The present work characterises how selection for reproduction (by comparing two generations - 16th and 36th - of the V line selected for litter size at weaning) or foundation for reproductive longevity (the LP line) can affect the blood lymphocytes populations of reproductive rabbit does under normal [conventional housing, average daily minimum and maximum temperatures of 14°C and 20°C, respectively] and heat stress conditions [climatic chamber, 25°C and 36°C] from the first to the second parturition. Housing under heat stress conditions significantly reduced the B lymphocytes counts in female rabbits (-34 × 10(6)/L; P<0.05). The highest lymphocytes population value in blood (total, T CD5(+), CD4(+) and CD8(+)) was noted at the first parturition, while the B lymphocytes count was significantly lower at the second parturition (-61 × 10(6)/L; P<0.05). Selection for litter size at weaning (V females) reduced the average counts of total and B lymphocytes in blood (-502 and -60 × 10(6)/L, respectively; P<0.01), mainly because these populations in V36 females continuously lowered from the first to the second parturition under normal housing conditions. Thus, more selected females (V36) at the second parturition showed significantly lower counts in blood for total, T CD5(+) and CD25(+) lymphocytes (-1303, -446 and -33 × 10(6)/L, respectively; P<0.05). The main differences in blood counts between V36 and V16 females disappeared when housed under heat stress conditions, except for T CD5(+) and CD25(+), which significantly increased (T CD5(+): +428 × 10(6)/L; CD25(+): +41 × 10(6)/L; P<0.01) in the V16 vs. V36 females on day 10 post-partum. Under normal conditions, no differences between LP and V36 females were found for most lymphocyte populations; only higher counts were noted in CD25(+) (+20 × 10(6)/L; P<0.05) for LP females. However, the lymphocytes counts [especially total (+1327 × 10(6)/L; P<0.01) and T CD5(+) (+376 × 10(6)/L; P<0.10)] of LP females

  2. Post-translational modification and conformational state of Heat Shock Protein 90 differentially affect binding of chemically diverse small molecule inhibitors

    PubMed Central

    Beebe, Kristin; Mollapour, Mehdi; Scroggins, Bradley; Prodromou, Chrisostomos; Xu, Wanping; Tokita, Mari; Taldone, Tony; Pullen, Lester; Zierer, Bettina K.; Lee, Min-Jung; Trepel, Jane; Buchner, Johannes; Bolon, Daniel; Chiosis, Gabriela; Neckers, Leonard

    2013-01-01

    Heat shock protein 90 (Hsp90) is an essential molecular chaperone in eukaryotes that facilitates the conformational maturation and function of a diverse protein clientele, including aberrant and/or over-expressed proteins that are involved in cancer growth and survival. A role for Hsp90 in supporting the protein homeostasis of cancer cells has buoyed interest in the utility of Hsp90 inhibitors as anti-cancer drugs. Despite the fact that all clinically evaluated Hsp90 inhibitors target an identical nucleotide-binding pocket in the N domain of the chaperone, the precise determinants that affect drug binding in the cellular environment remain unclear, and it is possible that chemically distinct inhibitors may not share similar binding preferences. Here we demonstrate that two chemically unrelated Hsp90 inhibitors, the benzoquinone ansamycin geldanamycin and the purine analog PU-H71, select for overlapping but not identical subpopulations of total cellular Hsp90, even though both inhibitors bind to an amino terminal nucleotide pocket and prevent N domain dimerization. Our data also suggest that PU-H71 is able to access a broader range of N domain undimerized Hsp90 conformations than is geldanamycin and is less affected by Hsp90 phosphorylation, consistent with its broader and more potent anti-tumor activity. A more complete understanding of the impact of the cellular milieu on small molecule inhibitor binding to Hsp90 should facilitate their more effective use in the clinic. PMID:23867252

  3. Heat-induced electrical signals affect cytoplasmic and apoplastic pH as well as photosynthesis during propagation through the maize leaf.

    PubMed

    Grams, Thorsten E E; Lautner, Silke; Felle, Hubert H; Matyssek, Rainer; Fromm, Jörg

    2009-04-01

    Combining measurements of electric potential and pH with such of chlorophyll fluorescence and leaf gas exchange showed heat stimulation to evoke an electrical signal (propagation speed: 3-5 mm s(-1)) that travelled through the leaf while reducing the net CO(2) uptake rate and the photochemical quantum yield of both photosystems (PS). Two-dimensional imaging analysis of the chlorophyll fluorescence signal of PS II revealed that the yield reduction spread basipetally via the veins through the leaf at a speed of 1.6 +/- 0.3 mm s(-1) while the propagation speed in the intervein region was c. 50 times slower. Propagation of the signal through the veins was confirmed because PS I, which is present in the bundle sheath cells around the leaf vessels, was affected first. Hence, spreading of the signal along the veins represents a path with higher travelling speed than within the intervein region of the leaf lamina. Upon the electrical signal, cytoplasmic pH decreased transiently from 7.0 to 6.4, while apoplastic pH increased transiently from 4.5 to 5.2. Moreover, photochemical quantum yield of isolated chloroplasts was strongly affected by pH changes in the surrounding medium, indicating a putative direct influence of electrical signalling via changes of cytosolic pH on leaf photosynthesis.

  4. Multi-zone cooling/warming garment

    NASA Technical Reports Server (NTRS)

    Koscheyev, Victor S. (Inventor); Leon, Gloria R. (Inventor); Dancisak, Michael J. (Inventor)

    2006-01-01

    A thermodynamically efficient garment for cooling and/or heating a human body. The thermodynamic efficiency is provided in part by targeting the heat exchange capabilities of the garment to specific areas and/or structures of the human body. The heat exchange garment includes heat exchange zones and one or more non-heat exchange zones, where the heat exchange zones are configured to correspond to one or more high density tissue areas of the human body when the garment is worn. A system including the garment can be used to exchange heat with the adjacent HD tissue areas under the control of a feedback control system. Sensed physiological parameters received by the feedback control system can be used to adjust the characteristics of heat exchange fluid moving within the heat exchange garment.

  5. Fault zone properties affecting the rupture evolution of the 2009 (Mw 6.1) L'Aquila earthquake (central Italy): Insights from seismic tomography

    NASA Astrophysics Data System (ADS)

    Di Stefano, R.; Chiarabba, C.; Chiaraluce, L.; Cocco, M.; De Gori, P.; Piccinini, D.; Valoroso, L.

    2011-05-01

    We have inverted P- and S-wave travel times from seismograms recorded by a dense local network to infer the velocity structure in the crustal volume where the April 6th 2009 main shock nucleated. The goal is to image local variations of P-wave velocity and Poisson ratio along the main shock fault zone for interpreting the complexity of the rupture history. The initial stages of the mainshock rupture are characterized by an emergent phase (EP) followed by an impulsive phase (IP) 0.87 s later. The EP phase is located in a very high VP and relatively low Poisson ratio (ν) region. The IP phase marks the beginning of the large moment release and is located outside the low ν volume. The comparison between the spatial variations of VP and Poisson ratio within the main shock nucleation volume inferred in this study with the rupture history imaged by inverting geophysical data allows us to interpret the delayed along-strike propagation in terms of heterogeneity of lithology and material properties.

  6. How lithology and climate affect REE mobility and fractionation along a shale weathering transect of the Susquehanna Shale Hills Critical Zone Observatory

    NASA Astrophysics Data System (ADS)

    Ma, L.; Jin, L.; Dere, A. L.; White, T.; Mathur, R.; Brantley, S. L.

    2012-12-01

    Shale weathering is an important process in global elemental cycles. Accompanied by the transformation of bedrock into regolith, many elements including rare earth elements (REE) are mobilized primarily by chemical weathering in the Critical Zone. Then, REE are subsequently transported from the vadose zone to streams, with eventual deposition in the oceans. REE have been identified as crucial and strategic natural resources; and discovery of new REE deposits will be facilitated by understanding global REE cycles. At present, the mechanisms and environmental factors controlling release, transport, and deposition of REE - the sources and sinks - at Earth's surface remain unclear. Here, we present a systematic study of soils, stream sediments, stream waters, soil water and bedrock in six small watersheds that are developed on shale bedrock in the eastern USA to constrain the mobility and fractionation of REE during early stages of chemical weathering. The selected watersheds are part of the shale transect established by the Susquehanna Shale Hills Observatory (SSHO) and are well suited to investigate weathering on shales of different compositions or within different climate regimes but on the same shale unit. Our REE study from SSHO, a small gray shale watershed in central Pennsylvania, shows that up to 65% of the REE (relative to parent bedrock) is depleted in the acidic and organic-rich soils due to chemical leaching. Both weathering soil profiles and natural waters show a preferential removal of middle REE (MREE: Sm to Dy) relative to light REE (La to Nd) and heavy REE (Ho to Lu) during shale weathering, due to preferential release of MREE from a phosphate phase (rhabdophane). Strong positive Ce anomalies observed in the regolith and stream sediments point to the fractionation and preferential precipitation of Ce as compared to other REE, in the generally oxidizing conditions of the surface environments. One watershed developed on the Marcellus black shale in

  7. Using heat as a tracer to estimate spatially distributed mean residence times in the hyporheic zone of a riffle-pool sequence

    USGS Publications Warehouse

    Naranjo, Ramon C.

    2013-01-01

    Biochemical reactions that occur in the hyporheic zone are highly dependent on the time solutes that are in contact with sediments of the riverbed. In this investigation, we developed a 2-D longitudinal flow and solute-transport model to estimate the spatial distribution of mean residence time in the hyporheic zone. The flow model was calibrated using observations of temperature and pressure, and the mean residence times were simulated using the age-mass approach for steady-state flow conditions. The approach used in this investigation includes the mixing of different ages and flow paths of water through advection and dispersion. Uncertainty of flow and transport parameters was evaluated using standard Monte Carlo and the generalized likelihood uncertainty estimation method. Results of parameter estimation support the presence of a low-permeable zone in the riffle area that induced horizontal flow at a shallow depth within the riffle area. This establishes shallow and localized flow paths and limits deep vertical exchange. For the optimal model, mean residence times were found to be relatively long (9–40.0 days). The uncertainty of hydraulic conductivity resulted in a mean interquartile range (IQR) of 13 days across all piezometers and was reduced by 24% with the inclusion of temperature and pressure observations. To a lesser extent, uncertainty in streambed porosity and dispersivity resulted in a mean IQR of 2.2 and 4.7 days, respectively. Alternative conceptual models demonstrate the importance of accounting for the spatial distribution of hydraulic conductivity in simulating mean residence times in a riffle-pool sequence.

  8. Modelling vegetation water-use and groundwater recharge as affected by climate variability in an arid-zone Acacia savanna woodland

    NASA Astrophysics Data System (ADS)

    Chen, Chao; Eamus, Derek; Cleverly, James; Boulain, Nicolas; Cook, Peter; Zhang, Lu; Cheng, Lei; Yu, Qiang

    2014-11-01

    For efficient and sustainable utilisation of limited groundwater resources, improved understanding of how vegetation water-use responds to climate variation and the corresponding controls on recharge is essential. This study investigated these responses using a modelling approach. The biophysically based model WAVES was calibrated and validated with more than two years of field experimental data conducted in Mulga (Acacia aneura) in arid central Australia. The validated model was then applied to simulate vegetation growth (as changes in overstory and understory leaf area index; LAI), vegetation water-use and groundwater recharge using observed climate data for the period 1981-2012. Due to large inter-annual climatic variability, especially precipitation, simulated annual mean LAI ranged from 0.12 to 0.35 for the overstory and 0.07 to 0.21 for the understory. These variations in simulated LAI resulted in vegetation water-use varying greatly from year-to-year, from 64 to 601 mm pa. Simulated vegetation water-use also showed distinct seasonal patterns. Vegetation dynamics affected by climate variability exerted significant controls on simulated annual recharge, which was greatly reduced to 0-48 mm compared to that (58-672 mm) only affected by climate. Understanding how climate variability and land use/land cover change interactively impact on groundwater recharge significantly improves groundwater resources management in arid and semi-arid regions.

  9. Recent (2008-10) water quality in the Barton Springs segment of the Edwards aquifer and its contributing zone, central Texas, with emphasis on factors affecting nutrients and bacteria

    USGS Publications Warehouse

    Mahler, Barbara J.; Musgrove, MaryLynn; Sample, Thomas L.; Wong, Corinne I.

    2011-01-01

    The Barton Springs zone, which comprises the Barton Springs segment of the Edwards aquifer and the watersheds to the west that contribute to its recharge, is in south-central Texas, an area with rapid growth in population and increasing amounts of land area affected by development. During November 2008-March 2010, an investigation of factors affecting the fate and transport of nutrients and bacteria in the Barton Springs zone was conducted by the U.S. Geological Survey (USGS), in cooperation with the Texas Commission on Environmental Quality. The primary objectives of the study were to characterize occurrence of nutrients and bacteria in the Barton Springs zone under a range of flow conditions; to improve understanding of the interaction between surface-water quality and groundwater quality; and to evaluate how factors such as streamflow variability and dilution affect the fate and transport of nutrients and bacteria in the Barton Springs zone. The USGS collected and analyzed water samples from five streams (Barton, Williamson, Slaughter, Bear, and Onion Creeks), two groundwater wells (Marbridge and Buda), and the main orifice of Barton Springs in Austin, Texas. During the period of the study, during which the hydrologic conditions transitioned from exceptional drought to wetter than normal, water samples were collected routinely (every 3 to 4 weeks) from the streams, wells, and spring and, in response to storms, from the streams and spring. All samples were analyzed for major ions, nutrients, the bacterium Escherichia coli, and suspended sediment. During the dry period, the geochemistry of groundwater at the two wells and at Barton Springs was dominated by flow from the aquifer matrix and was relatively similar and unchanging at the three sites. At the onset of the wet period, when the streams began to flow, the geochemistry of groundwater samples from the Marbridge well and Barton Springs changed rapidly, and concentrations of most major ions and nutrients and

  10. Cold Climate Heat Pump

    DTIC Science & Technology

    2013-08-01

    central heating , cooling, and air conditioning (HVAC) system . Both buildings had two zones for heating and cooling, which allowed for a direct...section calls for improved efficiency of mechanical systems as well as an increase of renewable resource usage. Current heating technologies in cold... heated refrigerant is injected into a mixing chamber between the two compressors. The injection leads to a gain in performance of the system through

  11. Determination of HEat Capacity of Yucca Mountain Strtigraphic Layers

    SciTech Connect

    T. Hadgu; C. Lum; J.E. Bean

    2006-06-20

    The heat generated from the radioactive waste to be placed in the proposed geologic repository at Yucca Mountain, Nevada, will affect the thermal-hydrology of the Yucca Mountain stratigraphic layers. In order to assess the effect of the movement of repository heat into the fractured rocks accurate determination of thermodynamic and hydraulic properties is important. Heat capacity is one of the properties that are required to evaluate energy storage in the fractured rock. Rock-grain heat capacity, the subject of this study, is the heat capacity of the solid part of the rock. Yucca Mountain consists of alternating lithostratigraphic units of welded and non-welded ash-flow tuff, mainly rhyolitic in composition and displaying varying degrees of vitrification and alteration. A number of methods exist that can be used to evaluate heat capacity of the stratigraphic layers that consist of different compositions. In this study, the mineral summation method has been used to quantify the heat capacity of the stratigraphic layers based on Kopp's rule. The mineral summation method is an addition of the weighted heat capacity of each mineral found in a specific layer. For this study the weighting was done based on the mass percentage of each mineral in the layer. The method utilized a mineralogic map of the rocks at the Yucca Mountain repository site. The Calico Hills formation and adjacent bedded tuff layers display a bimodal mineral distribution of vitric and zeolitic zones with differing mineralogies. Based on this bimodal distribution in zeolite abundance, the boundary between the vitric and zeolitic zones was selected to be 15% zeolitic abundance. Thus, based on the zeolite abundance, subdivisions have been introduced to these layers into ''vitric'' and ''zeolitic'' zones. Heat capacity values have been calculated for these layers both as ''layer average'' and ''zone average''. The heat capacity determination method presented in this report did not account for spatial

  12. Hydrogeology, Water Chemistry, and Factors Affecting the Transport of Contaminants in the Zone of Contribution of a Public-Supply Well in Modesto, Eastern San Joaquin Valley, California

    USGS Publications Warehouse

    Jurgens, Bryant C.; Burow, Karen R.; Dalgish, Barbara A.; Shelton, Jennifer L.

    2008-01-01

    Ground-water chemistry in the zone of contribution of a public-supply well in Modesto, California, was studied by the U.S. Geological Survey National Water Quality Assessment (NAWQA) Program's topical team for Transport of Anthropogenic and Natural Contaminants (TANC) to supply wells. Twenty-three monitoring wells were installed in Modesto to record baseline hydraulic information and to collect water-quality samples. The monitoring wells were divided into four categories that represent the chemistry of different depths and volumes of the aquifer: (1) water-table wells were screened between 8.5 and 11.7 m (meter) (28 and 38.5 ft [foot]) below land surface (bls) and were within 5 m (16 ft) of the water table; (2) shallow wells were screened between 29 and 35 m (95 and 115 ft) bls; (3) intermediate wells were screened between 50.6 and 65.5 m (166 and 215 ft) bls; and (4) deep wells are screened between 100 to 106 m (328 and 348 ft) bls. Inorganic, organic, isotope, and age-dating tracers were used to characterize the geochemical conditions in the aquifer and understand the mechanisms of mobilization and movement of selected constituents from source areas to a public-supply well. The ground-water system within the study area has been significantly altered by human activities. Water levels in monitoring wells indicated that horizontal movement of ground water was generally from the agricultural areas in the northeast towards a regional water-level depression within the city in the southwest. However, intensive pumping and irrigation recharge in the study area has caused large quantities of ground water to move vertically downward within the regional and local flow systems. Analysis of age tracers indicated that ground-water age varied from recent recharge at the water table to more than 1,000 years in the deep part of the aquifer. The mean age of shallow ground water was determined to be between 30 and 40 years. Intermediate ground water was determined to be a mixture

  13. etude experimentale de la propagation de fissures de fatigue dans la zone affectee thermiquement de joints soudes de roues de turbines hydrauliques

    NASA Astrophysics Data System (ADS)

    Trudel, Alexandre

    This thesis presents the results of a comprehensive experimental study on the fatigue crack propagation behavior in aqueous environment of the heat affected zone of CA6NM stainless steel hydraulic turbine runner welds. The initial objective of this project was to determine the fatigue crack growth properties of the heat affected zone. To achieve this, standardized fatigue crack growth tests in aqueous environment were performed to determine the crack growth threshold DeltaKth, and the Paris relationship constants C and m of the heat affected zone. Given potential experimental uncertainties arising from the growth of a crack confined to the heat affected zone, fatigue crack growth tests in an aqueous environment at constant stress intensity factor range (DeltaK) were performed so that the crack would propagate across the heat affected zone. These tests allowed to better appreciate the fatigue crack growth resistance variation between the three zones of the weld, i.e., the filler metal, the heat affected zone and the base metal. Various experimental objectives were supplemented to these two primary objectives. A CA6NM plate was welded to generate a layer of filler metal over its entire surface. The welded plate was cut in two equal pieces, one of which was post-weld heat treated in order to study the effect of this treatment on the fatigue crack growth behavior. Compact tension type fatigue specimens were machined from the welded plates. Rectangular samples were also collected to allow the characterization of the weld. Metallographic observations and X-ray diffraction measurements of the three zones of the weld (filler metal, heat affected zone and base metal) were conducted in order to characterize the microstructure. This microstructural characterization combined with metallographic observations of the crack path profiles were useful in assessing the microstructural effects acting on the fatigue crack growth behavior of the weld. Microhardness measurements were

  14. Floristic zones and aeroallergen diversity.

    PubMed

    Weber, Richard W

    2003-08-01

    The interplay of geographic, geochemical, and meteorologic factors combines to define distinct floristic zones in North America. Latitude, elevation, Pacific or Atlantic Ocean influence, continental air mass influence, mountains, and hills are contributory geographic factors. Hardiness zones are defined by the nadir of temperature, which strongly affects the survival of individual plant species. There are 12 hardiness zones from the northernmost tundra to the tropics of Mexico. Although it is useful to consider the 10 major floristic zones, the hardiness zones cut across these zones and characterize subregions. A multiplicity of local terrain effects, such as soil porosity and acidity, and sun exposure also impact on plant growth. The ability of plant species, whether woody shrubs and trees, or herbaceous weeds and grasses, to adapt to conditions within the floristic zones determines their range. This article identifies the major aeroallergenic species and the regions in which they are most prevalent.

  15. A comparative study of results obtained in magnetotelluric deep soundings in Villarrica active volcano zone (Chile) with gravity investigations, distribution of earthquake foci, heat flow empirical relationships, isotopic geochemistry 87Sr/ 86Sr and SB systematics

    NASA Astrophysics Data System (ADS)

    Muñoz, M.; Fournier, H.; Mamani, M.; Febrer, J.; Borzotta, E.; Maidana, A.

    The first magnetotelluric deep soundings in Chile were carried out during 1986 in the Villarrica active volcano zone (39°25'S, 71°57'W). In the TM mode of polarization, the curves show a distorted segment with dispersion. A static distortion at long periods is observed in curves in the TE mode of polarization; the segment was shifted vertically to fit the geomagnetic global model values at daily periods. This modified curve was used for 1D modelling to determine the electrical structure in the study area. The upper level of the intermediate conducting layer of resistivity 20-60 ω m is found to be at 35-50 km depth. A higher resistivity layer (600 ω m), starting at 100 km depth, may be resolved in the intermediate conducting layer. A sharp decrease in the resistivity is shown by the model at 500 km. Large heterogeneities at the level of the conducting layer encountered in the 1D modelling, and increased resistivity of the ultimate layer, may account for distortion observed at long periods. Two-dimensional test models show that the conducting layer in the area of Villarrica volcano may be an anomalous heated layer surrounded by rocks of higher resistivity of about 2 × 10 3 ω m. These features correspond to the interaction with a subsiding oceanic lithosphere resulting in a complex thermal structure and perturbed resistivity distribution in transition zones of the Pacific type such as Chile, and to the existence of a megafault and a system of fractures in the sounding area. These facts make it difficult to determine the conductance of the electrical asthenosphere. The parameters of the model structure correlate well with geophysical and geochemical results obtained in the area by other workers. Gravity studies indicate a maximum crustal thickness of about 37 km, which implies a non-full compensation according to the Airy hypothesis. The morphology of the Wadati-Benioff zone clearly shows a sharp decrease of earthquake foci at 50 km depth, and a reinitiation of

  16. Archaeal dominated ammonia-oxidizing communities in Icelandic grassland soils are moderately affected by long-term N fertilization and geothermal heating

    PubMed Central

    Daebeler, Anne; Abell, Guy C. J.; Bodelier, Paul L. E.; Bodrossy, Levente; Frampton, Dion M. F.; Hefting, Mariet M.; Laanbroek, Hendrikus J.

    2012-01-01

    The contribution of ammonia-oxidizing bacteria and archaea (AOB and AOA, respectively) to the net oxidation of ammonia varies greatly between terrestrial environments. To better understand, predict and possibly manage terrestrial nitrogen turnover, we need to develop a conceptual understanding of ammonia oxidation as a function of environmental conditions including the ecophysiology of associated organisms. We examined the discrete and combined effects of mineral nitrogen deposition and geothermal heating on ammonia-oxidizing communities by sampling soils from a long-term fertilization site along a temperature gradient in Icelandic grasslands. Microarray, clone library and quantitative PCR analyses of the ammonia monooxygenase subunit A (amoA) gene accompanied by physico-chemical measurements of the soil properties were conducted. In contrast to most other terrestrial environments, the ammonia-oxidizing communities consisted almost exclusively of archaea. Their bacterial counterparts proved to be undetectable by quantitative polymerase chain reaction suggesting AOB are only of minor relevance for ammonia oxidation in these soils. Our results show that fertilization and local, geothermal warming affected detectable ammonia-oxidizing communities, but not soil chemistry: only a subset of the detected AOA phylotypes was present in higher temperature soils and AOA abundance was increased in the fertilized soils, while soil physio-chemical properties remained unchanged. Differences in distribution and structure of AOA communities were best explained by soil pH and clay content irrespective of temperature or fertilizer treatment in these grassland soils, suggesting that these factors have a greater potential for ecological niche-differentiation of AOA in soil than temperature and N fertilization. PMID:23060870

  17. Disruption of the three cytoskeletal networks in mammalian cells does not affect transcription, translation, or protein translocation changes induced by heat shock.

    PubMed Central

    Welch, W J; Feramisco, J R

    1985-01-01

    Mammalian cells show a complex series of transcriptional and translational switching events in response to heat shock treatment which ultimately lead to the production and accumulation of a small number of proteins, the so-called heat shock (or stress) proteins. We investigated the heat shock response in both qualitative and quantitative ways in cells that were pretreated with drugs that specifically disrupt one or more of the three major cytoskeletal networks. (These drugs alone, cytochalasin E and colcemid, do not result in induction of the heat shock response.) Our results indicated that disruption of the actin microfilaments, the vimentin-containing intermediate filaments, or the microtubules in living cells does not hinder the ability of the cell to undergo an apparently normal heat shock response. Even when all three networks were simultaneously disrupted (resulting in a loose, baglike appearance of the cells), the cells still underwent a complete heat shock response as assayed by the appearance of the heat shock proteins. In addition, the major induced 72-kilodalton heat shock protein was efficiently translocated from the cytoplasm into its proper location in the nucleus and nucleolus irrespective of the condition of the three cytoskeletal elements. Images PMID:4040602

  18. Floating zone melting of cadmium telluride

    NASA Technical Reports Server (NTRS)

    Chang, Wen-Ming; Regel, L. L.; Wilcox, W. R.

    1992-01-01

    To produce superior crystals of cadmium telluride, floating zone melting in space has been proposed. Techniques required for floating zone melting of cadmium telluride are being developed. We have successfully float-zoned cadmium telluride on earth using square rods. A resistance heater was constructed for forming the molten zone. Evaporation of the molten zone was controlled by adding excess cadmium to the growth ampoule combined with heating of the entire ampoule. An effective method to hold the feed rod was developed. Slow rotation of the growth ampoule was proven experimentally to be necessary to achieve a complete symmetric molten zone. Most of the resultant cylindrical rods were single crystals with twins. Still needed is a suitable automatic method to control the zone length. We tried a fiber optical technique to control the zone length, but experiments showed that application of this technique to automate zone length control is unlikely to be successful.

  19. Single-Heater, Three-Zone Furnace

    NASA Technical Reports Server (NTRS)

    Gernert, Nelson J.; Shauback, Robert M.

    1993-01-01

    Temperature profile shaped with help of thermal barriers. Proposed furnace for use in experiments on growth of crystals of highly pure material in ampoule provides three temperature zones, yet contains only one heat-pipe liner and one heater and operates with only one controller. Three temperature zones established as thermal resistances of wicks and noncondensible gas reduces flows of heat into channel containing ampoule. Motion of ampoule along channel causes gradients of temperature to move along specimen in ampoule. Variety of three-zone temperature profiles in furnace created by changing thermal resistances of zones and injecting noncondensible gas at appropriate point. Furnace used for variety of experiments.

  20. Growth of high T{sub c} superconducting fibers using a miniaturized laser-heated float zone process. Final technical report, January 15, 1989--December 31, 1994

    SciTech Connect

    Feigelson, R.S.; Route, R.K.; DeMattei, R.C.

    1995-04-01

    This report summarizes a four year program on the use of the laser-heated pedestral growth (LHPG) process for the preparation of long, flexible fibers of the high T{sub c} copper-oxide ceramic superconductors having wire-like morphology. The major question addressed was whether the LHPG method could produce high T{sub c} fibers of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} (2212) in lengths long enough for use as superconducting wires. Cold-pressing and sintering methods were developed to prepare uniform, single phase ceramic feedstock. Phase equilibrium studies revealed the relationship between thermal gradients, interface shape and phases produced by the LHPG process during incongruent solidification. The highest critical current densities over measured in bulk samples of Bi-2212 material, 60,000 A/cm{sup 2} at 68K, were achieved in single crystal and/or highly grain-oriented fibers. The first ever flexible, multi-cm fibers ({le}100 {mu}m in diameter) were prepared. Fibers diameters were ultimately reduced to 25 {mu}m (1 cm in length), and we were able to grow them up to 14 cm in length (100 {mu}m diameter). These fibers could be bent in radii less than 5 cm, but max. growth rates of {approximately}10 mm/hr did not permit them to be grown long enough for prototype motor windings. Superconducting Bi-2212 grain-aligned ribbons were grown for the first time by the LHPG method using platinum guide wires.

  1. Factors affecting thermal resistance of Salmonella enterica serovar enteritidis ODA 99-30581-13 in shell egg contents and use of heat-ozone combinations for egg pasteurization.

    PubMed

    Perry, Jennifer J; Yousef, Ahmed E

    2013-02-01

    Infection of laying hens with Salmonella enterica serovar Enteritidis leads to deposition of the pathogen into the albumen or yolk of forming eggs. Heat treatment can inactivate internalized Salmonella Enteritidis in shell eggs, but factors such as the nature and location of contamination may influence the efficacy of thermal treatments. In the current research, natural contamination was mimicked by introducing small inocula of Salmonella Enteritidis into different locations of shell eggs and incubating inoculated eggs. These pathogen-containing eggs were heated at 57°C for 40 min, and temperature within eggs was monitored at the locations of inocula. Comparison of inactivation at equivalent internal temperatures revealed similar levels of lethality regardless of inoculum location. Refrigeration between incubation and heat treatment did not increase thermal resistance of cells in albumen but decreased cell inactivation in yolk. Sequential application of heat and gaseous ozone allows for the development of a process capable of decontaminating shell eggs with minimal thermal treatment and impact on egg quality. Inoculated eggs were subjected to (i) an immersion heating process similar to that used in commercial pasteurization or (ii) immersion heating, at reduced duration, followed by vacuum (50.8 kPa) and treatment with ozone gas (maximum 160 g/m(3)) under pressure (∼187.5 kPa). All treatments tested produced greater than 5-log inactivation, which is required for "pasteurization" processes. Differences were observed in the visual quality of eggs depending on treatment parameters. Application of ozone subsequent to heating allows for a significant reduction in heating time without decreasing process lethality.

  2. "E" Heating Head

    NASA Technical Reports Server (NTRS)

    Fox, Robert L.; Swaim, Robert J.; Johnson, Samuel D.; Coultrip, Robert H.; Phillips, W. Morris; Copeland, Carl E.

    1994-01-01

    Two separate areas heated inductively for adhesive bonding in single operation. "E" heating head developed to satisfy need for fast-acting and reliable induction heating device. Used in attaching "high-hat" stiffeners to aircraft panels. Incorporates principles and circuitry of toroid joining gun. Width and length configured to provide variously sized heat zones, depending on bonding requirements. Lightweight, portable and provides rapid, reliable heating of dual areas in any environment. Well suited for flight-line and depot maintenance, and battlefield repair. Also useful in automotive assembly lines to strengthen automobile panels.

  3. Short-Term Heat Shock Affects Host–Virus Interaction in Mice Infected with Highly Pathogenic Avian Influenza Virus H5N1

    PubMed Central

    Xue, Jia; Fan, Xiaoxu; Yu, Jing; Zhang, Shouping; Xiao, Jin; Hu, Yanxin; Wang, Ming

    2016-01-01

    Highly pathogenic avian influenza virus (HPAIV) H5N1 is a highly contagious virus that can cause acute respiratory infections and high human fatality ratio due to excessive inflammatory response. Short-term heat shock, as a stressful condition, could induce the expression of heat shock proteins that function as molecular chaperones to protect cells against multiple stresses. However, the protective effect of short-term heat shock in influenza infection is far from being understood. In this study, mice were treated at 39°C for 4 h before being infected with HPAIV H5N1. Interestingly, short-term heat shock significantly increased the levels of HSP70 and pro-inflammatory cytokines IL-6, TNF-α, IFN-β, and IFN-γ in the lung tissues of mice. Following HPAIV H5N1 infection, short-term heat shock alleviated immunopathology and viral replication in lung tissue and repressed the weight loss and increased the survival rate of H5N1-infected mice. Our data reported that short-term heat shock provided beneficial anti-HPAIV H5N1 properties in mice model, which offers an alternative strategy for non-drug prevention for influenza infection. PMID:27379054

  4. Short-Term Heat Shock Affects Host-Virus Interaction in Mice Infected with Highly Pathogenic Avian Influenza Virus H5N1.

    PubMed

    Xue, Jia; Fan, Xiaoxu; Yu, Jing; Zhang, Shouping; Xiao, Jin; Hu, Yanxin; Wang, Ming

    2016-01-01

    Highly pathogenic avian influenza virus (HPAIV) H5N1 is a highly contagious virus that can cause acute respiratory infections and high human fatality ratio due to excessive inflammatory response. Short-term heat shock, as a stressful condition, could induce the expression of heat shock proteins that function as molecular chaperones to protect cells against multiple stresses. However, the protective effect of short-term heat shock in influenza infection is far from being understood. In this study, mice were treated at 39°C for 4 h before being infected with HPAIV H5N1. Interestingly, short-term heat shock significantly increased the levels of HSP70 and pro-inflammatory cytokines IL-6, TNF-α, IFN-β, and IFN-γ in the lung tissues of mice. Following HPAIV H5N1 infection, short-term heat shock alleviated immunopathology and viral replication in lung tissue and repressed the weight loss and increased the survival rate of H5N1-infected mice. Our data reported that short-term heat shock provided beneficial anti-HPAIV H5N1 properties in mice model, which offers an alternative strategy for non-drug prevention for influenza infection.

  5. Microgravity Silicon Zoning Investigation

    NASA Technical Reports Server (NTRS)

    Kern, E. L.

    1985-01-01

    This research program is directed toward the understanding of the float zone crystal growth process, the melt interactions which lead to crystal inhomogeneities, and the influence of microgravity on reducing these inhomogeneities. Silicon was selected as the model crystal because its inhomogeneities lead to known variations in device performance, and because the mechanisms involved in its growth are understood better than for other high temperature crystals. The objective of the program is to understand the growth mechanisms in float zone growth and thereby determine the feasibility and advantages of float zone growth of silicon under microgravity conditions. This will be done by characterizing the growth at g = 1, projecting the changes in melt flows due to microgravity, observing these in space growth and determining the effects on defective inhomogeneities. A Thin Rod Zoner was constructed as a laboratory prototype for flight growth of 5 mm diameter silicon crystals, which can be done within the power and cooling capabilities of shuttle flights. A new method of zoning silicon, using resistance heating, has resulted in melting 5 mm diameter ingots.

  6. Modeling hyporheic zone processes

    USGS Publications Warehouse

    Runkel, Robert L.; McKnight, Diane M.; Rajaram, Harihar

    2003-01-01

    Stream biogeochemistry is influenced by the physical and chemical processes that occur in the surrounding watershed. These processes include the mass loading of solutes from terrestrial and atmospheric sources, the physical transport of solutes within the watershed, and the transformation of solutes due to biogeochemical reactions. Research over the last two decades has identified the hyporheic zone as an important part of the stream system in which these processes occur. The hyporheic zone may be loosely defined as the porous areas of the stream bed and stream bank in which stream water mixes with shallow groundwater. Exchange of water and solutes between the stream proper and the hyporheic zone has many biogeochemical implications, due to differences in the chemical composition of surface and groundwater. For example, surface waters are typically oxidized environments with relatively high dissolved oxygen concentrations. In contrast, reducing conditions are often present in groundwater systems leading to low dissolved oxygen concentrations. Further, microbial oxidation of organic materials in groundwater leads to supersaturated concentrations of dissolved carbon dioxide relative to the atmosphere. Differences in surface and groundwater pH and temperature are also common. The hyporheic zone is therefore a mixing zone in which there are gradients in the concentrations of dissolved gasses, the concentrations of oxidized and reduced species, pH, and temperature. These gradients lead to biogeochemical reactions that ultimately affect stream water quality. Due to the complexity of these natural systems, modeling techniques are frequently employed to quantify process dynamics.

  7. Normalization and sound zone determination in pulse thermographic NDE

    NASA Astrophysics Data System (ADS)

    Sripragash, Letchuman; Sundaresan, Mannur

    2017-02-01

    Thermographic nondestructive evaluation is quick and effective in detecting damage particularly for composite structures. Pulse thermographic nondestructive evaluation (TNDE) technique can potentially provide information on defect dimensions, such as the depth at which the defect is located. However, there are a number of extraneous variables that affect the signal obtained during these tests, such as non-uniformity in the heat pulse applied and differences in the emissivity of the surfaces from specimen to specimen. In addition, the identification of defect free areas in the image is a challenge. As in other NDE procedures calibration specimens would be of help, but calibration specimens corresponding to complex damage states in composite materials are difficult to fabricate. Results from validated numerical simulations can complement calibration specimens. However, the thermo-mechanical properties of the test object as well as the amount of heat energy absorbed in the field tests are not readily available for such models. This paper presents an extension of the thermographic signal reconstruction (TSR) procedure in which the temperature and the time scales are respectively normalized with equilibrium temperature and the break time. A benefit of such normalization is the ability to directly measure the defect depth as a fraction of plate thickness. In order to implement this normalization procedure, sound zone profile definition is required. A new approach for determining sound zone profile has been developed. Finally, determination of sound zone is affected by non-uniform heating, and a method of minimizing the effects of non-uniform heating is proposed. The performance of these new approaches on actual experimental results are presented.

  8. Study of Divertor Heat Patterns Induced by LHCD L-Mode Plasmas Using an Infra-Red Camera System on EAST

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Gan, Kaifu; Gong, Xianzu; Zhang, Xiaodong; Wang, Fumin; Yang, Zhendong; Chen, Meiwen; Wang, Xiaoqiong

    2015-10-01

    Divertor heat patterns induced by Lower Hybrid Current Drive (LHCD) L-mode plasmas are investigated using an infra-red (IR) camera system on an Experimental Advanced Superconducting Tokamak (EAST). A two-dimensional finite element analysis code DFlux is used to compute heat flux along the poloidal divertor target and corresponding quantities. Outside the Origin Strike Zone (OSZ), a Second Peak Heat Flux (SPHF) zone, where the heat flux is even stronger than that at the OSZ, appears on the lower-outer (LO) divertor plates with LHCD and disappears immediately after switching off the LHCD. The main heat-flux shifts from the SPHF zone towards the OSZ when the divertor configuration converts from double null to lower single null, indicating that the growth of the SPHF zone is apparently affected by a plasma magnetic configuration. The heat patterns on the LO divertor plates are observed to be different from that on the lower-inner (LI) targets as the SPHF zone appears only on the LO divertor target. It is also found that the heat flux at the SPHF zone was obviously enhanced after the Supersonic Molecule Beam Injection (SMBI) pulse. supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2014GB101001 and 2014GB101002)

  9. Three-zonal engineering method of heat calculation for fluidized bed furnaces based on data on commercial investigations of heat generation distribution during biomass combustion

    NASA Astrophysics Data System (ADS)

    Litun, D. S.; Ryabov, G. A.

    2016-02-01

    A three-zonal method of heat calculation of furnaces for combustion of biomass and low-caloric fuel in the fluidized bed is described. The method is based on equations of thermal and material balances that account for heat generation by fuel in the zone, heat-and-mass transfer heat exchange between the furnace media and surfaces that bound the zone, and heat-and-mass transfer between furnace zones. The calculation procedure for heat generation by fuel in the fluidized bed (FB) using the heat generation portion by the fuel is proposed. Based on commercial investigations, the main factors that affect the average temperature in the FB and the portion of fuel heat that is released in the FB are determined. Results of commercial investigations showed that the airflow coefficient in the FB should be recognized as the main operation parameter that affects the average temperature in the FB and, consequently, heat generation in the FB. The gas flow rate in the FB can be marked out as the second factor that affects the consumption degree of oxidizer supplied in the FB. Commercial investigations revealed that mixing is affected by the gas flow rate in the FB and the bed material particle size, which may be changed during the boiler operation because of the agglomeration of particles of sand and ash. The calculation processing of commercial investigations on a KM-75-40M boiler of a CHP-3 of an Arkhangelsk Pulp and Paper Mill (APPM), which was carried out using the inverse problem procedure by means of a developed computer program, determined the range of the fuel heat release share in the FB, which was 0.26-0.45 at an excess air factor of 0.59-0.93 in the bed, and the heat release share in the maximum temperature zone in the total heat release in the superbed space. The heat release share in the bed is determined as an approximating function of the excess air factor in the bed and the fluidization number. The research results can be used during designing boilers with the

  10. 76 FR 18391 - Safety Zone; Texas International Boat Show Power Boat Races; Corpus Christi Marina, Corpus...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... zone will be implemented for the 15 minutes before each race or race heat. The same methods of... safety zone approximately 15 minutes following the conclusion of each race or race heat when the power... race heat. Vessels may transit through the safety zone with permission from the Captain of the...

  11. Treating nahcolite containing formations and saline zones

    DOEpatents

    Vinegar, Harold J

    2013-06-11

    A method for treating a nahcolite containing subsurface formation includes removing water from a saline zone in or near the formation. The removed water is heated using a steam and electricity cogeneration facility. The heated water is provided to the nahcolite containing formation. A fluid is produced from the nahcolite containing formation. The fluid includes at least some dissolved nahcolite. At least some of the fluid is provided to the saline zone.

  12. Microwave heating inactivates Shiga Toxin (Stx2) in reconstituted fat-free Milk and adversely affects the nutritional value of cell culture medium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microwave exposure is a convenient and widely used method for defrosting, heating, and cooking numerous foods. Microwave cooking is also reported to kill pathogenic microorganisms that often contaminate food. Microwaves act by causing polar molecules in food, such as water, to rapidly rotate, thus...

  13. Partial fuel stratification to control HCCI heat release rates : fuel composition and other factors affecting pre-ignition reactions of two-stage ignition fuels.

    SciTech Connect

    Dec, John E.; Sjoberg, Carl-Magnus G.; Cannella, William; Yang, Yi; Dronniou, Nicolas

    2010-11-01

    Homogeneous charge compression ignition (HCCI) combustion with fully premixed charge is severely limited at high-load operation due to the rapid pressure-rise rates (PRR) which can lead to engine knock and potential engine damage. Recent studies have shown that two-stage ignition fuels possess a significant potential to reduce the combustion heat release rate, thus enabling higher load without knock.

  14. Moving-Gradient Furnace With Constant-Temperature Cold Zone

    NASA Technical Reports Server (NTRS)

    Gernert, Nelson J.; Shaubach, Robert M.

    1993-01-01

    Outer heat pipe helps in controlling temperature of cold zone of furnace. Part of heat-pipe furnace that includes cold zone surrounded by another heat pipe equipped with heater at one end and water cooling coil at other end. Temperature of heat pipe maintained at desired constant value by controlling water cooling. Serves as constant-temperature heat source or heat sink, as needed, for gradient of temperature as gradient region moved along furnace. Proposed moving-gradient heat-pipe furnace used in terrestrial or spaceborne experiments on directional solidification in growth of crystals.

  15. Treating tar sands formations with karsted zones

    DOEpatents

    Vinegar, Harold J.; Karanikas, John Michael

    2010-03-09

    Methods for treating a tar sands formation are described herein. The tar sands formation may have one or more karsted zones. Methods may include providing heat from one or more heaters to one or more karsted zones of the tar sands formation to mobilize fluids in the formation. At least some of the mobilized fluids may be produced from the formation.

  16. Spin transition zone in Earth's lower mantle

    SciTech Connect

    Lin, J.-F.; Vanko, G.; Jacobsen, S.D.; Iota, V.; Struzhkin, V.V.; Prakapenka, V.B.; Kuznetsov, A.; Yoo, C.-S.

    2008-06-16

    Mineral properties in Earth's lower mantle are affected by iron electronic states, but representative pressures and temperatures have not yet been probed. Spin states of iron in lower-mantle ferropericlase have been measured up to 95 gigapascals and 2000 kelvin with x-ray emission in a laser-heated diamond cell. A gradual spin transition of iron occurs over a pressure-temperature range extending from about 1000 kilometers in depth and 1900 kelvin to 2200 kilometers and 2300 kelvin in the lower mantle. Because low-spin ferropericlase exhibits higher density and faster sound velocities relative to the high-spin ferropericlase, the observed increase in low-spin (Mg,Fe)O at mid-lower mantle conditions would manifest seismically as a lower-mantle spin transition zone characterized by a steeper-than-normal density gradient.

  17. Increasing Soil Heat Storage across Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Troy, T. J.; Wood, E. F.

    2009-12-01

    Recent studies have shown that the ocean, atmosphere, cryosphere, and continental land masses have gained heat over the past century [Hansen et al., 2009; Beltrami et al., 2002]. Although soil heat storage may play a lesser role than the ocean in absorbing heat, it plays an important role in identifying and understanding changes in climate, especially relating to changes in the permafrost active layer. Northern Eurasia has experienced some of the strongest warming trends over the twentieth century, and in situ measurements of soil temperature have shown that the land surface is responding by warming accordingly. The observational network presents an incomplete picture of the soil heat gain because the network is sparse and temperature does not account for latent heat effects and moisture dynamics in the soil column, which also affect the change in enthalpy. In the winter, the snowpack insulates the soil column, which may decouple the air and ground temperatures. To bridge this gap in our understanding, we use the VIC land surface model, which solves for both the energy and water budget at the land surface and subsurface with a 50 meter soil column, to calculate the change in ground heat between 1901 and 2005 after a 500-year model spin-up. We find that the heat stored in the soil column experienced a small but steady increase at the beginning of the twentieth century, with an abrupt increase in heat accumulation after 1980, indicating a possible tipping point in the system. There is heterogeneity in the spatial pattern of heat accumulation, with larger accumulation in the southern Ob River basin and the permafrost-dominated regions of Eurasia. The modeled heat accumulation in the permafrost zone confirms concerns in the scientific literature that the permafrost is particularly vulnerable to climate changes.

  18. Predicting km-scale shear zone formation

    NASA Astrophysics Data System (ADS)

    Gerbi, Christopher; Culshaw, Nicholas; Shulman, Deborah; Foley, Maura; Marsh, Jeffrey

    2015-04-01

    gradients but are insufficient to maintain them because the stress perturbations will dissipate with deformation. Metamorphism can unquestionably cause sufficient rheological change, but only in certain rock types: for example, granitoids have much less capacity for metamorphically induced rheologic change than do mafic rocks. The magnitude of phase geometry variation observed in natural systems suggests that morphological change (e.g., interconnection of weak phases) likely has little direct affect on strength changes, although other textural factors related to diffusion paths and crystallographic orientation could play a significant role. Thermal perturbation, mainly in the form of shear heating, remains potentially powerful but inconclusive. Taken together, these observations indicate that a simple algorithm predicting shear zone formation will not succeed in many geologically relevant instances. One significant reason may be that the inherent lithologic variation at the km scale, such as observed in the Central Gneiss belt, prevents the development of self-organized strain patterns that would form in more rheologically uniform systems.

  19. Analysis of heat recovery of diesel engine using intermediate working fluid

    NASA Astrophysics Data System (ADS)

    Jin, Lei; Zhang, Jiang; Tan, Gangfeng; Liu, Huaming

    2017-02-01

    The organic Rankine cycle (ORC) is an effective way to recovery the engine exhaust heat. The thermal stability of the evaporation system is significant for the stable operation of the ORC system. In this paper, the performance of the designed evaporation system which combines with the intermediate fluid for recovering the exhaust waste heat from a diesel engine is evaluated. The thermal characteristics of the target diesel engine exhaust gas are evaluated based on the experimental data firstly. Then, the mathematical model of the evaporation system is built based on the geometrical parameters and the specific working conditions of ORC. Finally, the heat transfer characteristics of the evaporation system are estimated corresponding to three typical operating conditions of the diesel engine. The result shows that the exhaust temperature at the evaporator outlet increases slightly with the engine speed and load. In the evaporator, the heat transfer coefficient of the Rankine working fluid is slightly larger than the intermediate fluid. However, the heat transfer coefficient of the intermediate fluid in the heat exchanger is larger than the exhaust side. The heat transfer areas of the evaporator in both the two-phase zone and the preheated zone change slightly along with the engine working condition while the heat transfer areas of the overheated zone has changed obviously. The maximum heat transfer rate occurs in the preheating zone while the minimum value occurs in the overheating zone. In addition, the Rankine working fluid temperature at the evaporator outlet is not sensitively affected by the torque and speed of the engine and the organic fluid flow is relatively stable. It is concluded that the intermediate fluid could effectively reduce the physical changes of Rankine working fluid in the evaporator outlet due to changes in engine operating conditions.

  20. Some molecular/crystalline factors that affect the sensitivities of energetic materials: molecular surface electrostatic potentials, lattice free space and maximum heat of detonation per unit volume.

    PubMed

    Politzer, Peter; Murray, Jane S

    2015-02-01

    We discuss three molecular/crystalline properties that we believe to be among the factors that influence the impact/shock sensitivities of energetic materials (i.e., their vulnerabilities to unintended detonation due to impact or shock). These properties are (a) the anomalously strong positive electrostatic potentials in the central regions of their molecular surfaces, (b) the free space per molecule in their crystal lattices, and (c) their maximum heats of detonation per unit volume. Overall, sensitivity tends to become greater as these properties increase; however these are general trends, not correlations. Nitramines are exceptions in that their sensitivities show little or no variation with free space in the lattice and heat of detonation per unit volume. We outline some of the events involved in detonation initiation and show how the three properties are related to different ones of these events.

  1. Changes in bioactive compounds and oxidative enzymes of fresh-cut pomegranate arils during storage as affected by deficit irrigation and postharvest vapor heat treatments.

    PubMed

    Peña-Estévez, María E; Gómez, Perla A; Artés, Francisco; Aguayo, Encarna; Martínez-Hernández, Ginés Benito; Galindo, Alejandro; Torecillas, Arturo; Artés-Hernández, Francisco

    2016-12-01

    The effect of postharvest vapor heat treatments at 95℃ (4, 7, and 10 s) regarding a conventional sanitizing treatment with 100 mg NaClO l(-1) on enzyme activities (phenylalanine ammonia lyase, polyphenol oxidase, and peroxidase), phenolic content, and total antioxidant capacity of fresh-cut pomegranates arils throughout 18 days at 5℃ was studied. Furthermore, the effect of two sustained deficit irrigation (SDI) strategies, compared to a standardly irrigated control (CTRL), was also studied on such quality parameters throughout storage. Arils from CTRL-irrigated fruit registered phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase initial activities of 60.6, 382, and 14.4 U g(-1) fw, respectively. Arils from sustained deficit irrigation fruit registered 46-58% lower phenylalanine ammonia lyase values while polyphenol oxidase and peroxidase activities did not register great variants (<9%) among both sustained deficit irrigation treatments. Postharvest vapor heat treatments enhanced phenylalanine ammonia lyase activity in those samples from sustained deficit irrigation fruit although no great peroxidase and polyphenol oxidase (<2-5%) increases were observed. Arils from SDI1 fruit registered higher phenolic content than those values reported for CTRL samples. However, phenolic compounds decreased during storage, in a greater extent for sustained deficit irrigation samples, although 7 s arils achieved better phenolic compounds retention in sustained deficit irrigation samples. Vapor heat treatments reduced up to twofold the total antioxidant capacity losses observed in samples sanitized by conventional NaOCl treatment during shelf life. Conclusively, postharvest vapor heat treatment for 7 and 10 s used to extend the shelf life of pomegranate arils up to 18 days at 5℃ reduced the losses of health-promoting compounds during storage compared to conventional NaOCl sanitizing treatment.

  2. Transparent multi-zone crystal growth furnace and method for controlling the same

    NASA Technical Reports Server (NTRS)

    Duval, Walter (Inventor); Batur, Celal (Inventor); Bennett, Robert J. (Inventor)

    2000-01-01

    A crystal growth system, comprising: a furnace; a plurality of heating elements coupled to said furnace, each said plurality of heating elements defining a heat zone, each said heating element set to a desired temperature value; a plurality of thermocouples associated with respective heat zones to detect a temperature value; a translation system for passing an ampoule containing crystal growth material through said furnace into said heat zones and providing a positional location of said ampoule and; a multi-variable self-tuning temperature controller connected to said plurality of heating elements, said plurality of thermocouples and said translation system, said controller monitoring each said zone temperature value and upon considering the thermal interaction of heating zones and the moving thermal inertia of the ampoule, adjusting voltage input to said heat zones to obtain optimal crystal growth within said ampoule.

  3. Transparent multi-zone crystal growth furnace and method for controlling the same

    NASA Technical Reports Server (NTRS)

    Duval, Walter (Inventor); Batur, Celal (Inventor); Bennett, Robert J. (Inventor)

    2001-01-01

    A crystal growth system, comprising: a furnace; a plurality of heating elements coupled to said furnace, each said plurality of heating elements defining a heat zone, each said heating element set to a desired temperature value; a plurality of thermocouples associated with respective heat zones to detect a temperature value; a translation system for passing an ampoule containing crystal growth material through said furnace into said heat zones and providing a positional location of said ampoule and; a multi-variable self-tuning temperature controller connected to said plurality of heating elements, said plurality of thermocouples and said translation system, said controller monitoring each said zone temperature value and upon considering the thermal interaction of heating zones and the moving thermal inertia of the ampoule, adjusting voltage input to said heat zones to obtain optimal crystal growth within said ampoule.

  4. Calibrated Heat Flow Model for Determining the Heat Conduction Losses in Laser Cutting of CFRP

    NASA Astrophysics Data System (ADS)

    Mucha, P.; Weber, R.; Speker, N.; Berger, P.; Sommer, B.; Graf, T.

    Laser machining has great potential regarding automation in fabrication of CFRP (carbon-fiber-reinforced plastics) parts, due to the nearly force and tool-wear free processing at high process speeds. The high vaporization temperatures and the large heat conductivity of the carbon fibers lead to a large heat transport into the sample. This causes the formation of a heat-affected zone and a decrease of the process speed. In the present paper,an analytical heat flow model was adapted in order to understand and investigate the heat conduction losses. Thermal sensors were embedded in samples at different distances from the kerf to fit the calculated to the measured temperatures. Heat conduction losses of up to 30% of the laser power were determined. Furthermore, the energy not absorbed by the sample, the energy for sublimating the composite material in the kerf, the energy for the formation of the HAZ, and the residual heat in the sample are compared in an energy balance.

  5. Heat pipe array heat exchanger

    DOEpatents

    Reimann, Robert C.

    1987-08-25

    A heat pipe arrangement for exchanging heat between two different temperature fluids. The heat pipe arrangement is in a ounterflow relationship to increase the efficiency of the coupling of the heat from a heat source to a heat sink.

  6. Connection Between Internal Structural Stresses of the Ist and the IInd kind and Operational Reliability of the Boiler Heating Surface

    NASA Astrophysics Data System (ADS)

    Lyubimova, Lyudmila; Tabakaev, Roman; Tashlykov, Alexander; Zavorin, Alexander; Zyubanov, Vadim

    2016-02-01

    This paper presents new approaches to solving problems of forecasting the life of heating surface of boilers, based on an analysis of internal structural stresses of the first and second kind that could affect the intragranular and intergranular strength and reliability of the pipeline in continuous operation by making it work without damage by preventing the disclosure of zone cracks.

  7. 24 CFR 3280.506 - Heat loss/heat gain.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.506 Heat... shall be provided with thermal insulation. (c) Manufactured homes designed for Uo Value Zone 3 shall be factory equipped with storm windows or insulating glass....

  8. Laying performance, digestibility and plasma hormones in laying hens exposed to chronic heat stress as affected by betaine, vitamin C, and/or vitamin E supplementation.

    PubMed

    Attia, Youssef A; Abd El-Hamid, Abd El-Hamid E; Abedalla, Ahmed A; Berika, Marfat A; Al-Harthi, Mohammed A; Kucuk, Osman; Sahin, Kazim; Abou-Shehema, Baha M

    2016-01-01

    Heat stress had a negative effect on laying hens' performance, thus this research was to study the influences of betaine (Bet, 1000 mg/kg betaine), vitamin C (VC, 200 mg/kg ascorbic acid), and vitamin E (VE, 150 mg/kg α-Tocopherol acetate) and their possible combinations on egg production, digestibility of nutrients, plasma hormones and reproductive organs of dual-purpose hens exposed to chronic heat stress. Two hundred and eighty eight hens and thirty-six cocks from 32 to 48 weeks of age were divided into nine treatment groups of four replicates, each containing eight hens and one cock. One group was kept under thermo-natural condition and the eight others were kept under chronic heat stress (CHS). One of these eight was used as a negative control, while the others were supplemented with VC, VE and/or betaine and their possible combinations. Body weights, laying rate, feed intake, and feed conversion ratio in hens reared under CHS rooster without any supplementation during 32 to 48 weeks of impairment (P = 0.0052) were recorded. Hens reared under heat stress and fed a diet supplemented with either Bet, VC, VE or combination of the supplements increased production traits. However, hens supplemented with VC showed the greatest production traits. Plasma glucose, estradiol-17 (E2), progesterone (P4), tri-iodothyronine (T3) and thyroxine (T4) decreased in hens reared under CHS and fed a diet with no supplementation compared to the other treatments (P = 0.001). Liver weights, spleen weights, thyroid gland weights, ovary weights, oviduct weights and oviduct lengths were lowest in hens reared under CHS and fed a diet with no supplementation (P = 0.0480). In conclusion, dual purpose hens reared under CHS and supplemented with VC at 200 mg/kg diet and Bet at 1000 mg/kg enhanced the laying performance and combated CHS.

  9. Abrasion resistant heat pipe

    DOEpatents

    Ernst, D.M.

    1984-10-23

    A specially constructed heat pipe is described for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

  10. Abrasion resistant heat pipe

    DOEpatents

    Ernst, Donald M.

    1984-10-23

    A specially constructed heat pipe for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

  11. Two years of combined high-intensity physical training and heat acclimatization affect lymphocyte and serum HSP70 in purebred military working dogs.

    PubMed

    Bruchim, Yaron; Aroch, Itamar; Eliav, Ady; Abbas, Atallah; Frank, Ilan; Kelmer, Efrat; Codner, Carolina; Segev, Gilad; Epstein, Yoram; Horowitz, Michal

    2014-07-15

    Military working dogs in hot countries undergo exercise training at high ambient temperatures for at least 9 mo annually. Physiological adaptations to these harsh conditions have been extensively studied; however, studies focusing on the underlying molecular adaptations are limited. In the current study, military working dogs were chosen as a model to examine the effects of superimposing endurance exercise on seasonal acclimatization to environmental heat stress. The lymphocyte HSP70 profile and extracellular HSP70 were studied in tandem with physiological performance in the dogs from their recruitment for the following 2 yr. Aerobic power and heat shock proteins were measured at the end of each summer, with physical performance tests (PPTs) in an acclimatized room (22°C). The study shows that together with a profound enhancement of aerobic power and physical performance, hsp72 mRNA induction immediately post-PPT and 45 min later, progressively increased throughout the study period (relative change in median lymphocyte hsp72 mRNA first PPT, 4.22 and 12.82; second PPT, 17.19 and 109.05, respectively), whereas induction of HSP72 protein was stable. These responses suggest that cellular/molecular adaptive tools for maintaining HSP72 homeostasis exist. There was also a significant rise in basal and peak median optical density extracellular HSP at the end of each exercise test (first PPT, 0.13 and 0.15; second PPT, 1.04 and 1.52, respectively). The relationship between these enhancements and improved aerobic power capacity is not yet fully understood.

  12. Gently sloping shear zones in the Belomorian Mobile Belt: Geology, structure, and P- T parameters

    NASA Astrophysics Data System (ADS)

    Kozlovskii, V. M.; Travin, V. V.; Korpechkov, D. I.; Zaitseva, M. N.; Kurdyukov, E. B.; Travin, A. V.; Terent'eva, L. B.; Savatenkov, V. M.

    2016-11-01

    The Belomorian Mobile Belt (BMB) in northern Karelia mostly consists of gently sloping shear zones, whose gneisses and migmatized amphibolites and blastomylonites are typically thinly banded, with their banding consistently dipping north- and northeastward. These gently sloping shear zones were not affected by folding after they were produced and are not cut by Paleoproterozoic metabasite dikes. Intrusive metabasites in the gently sloping shear zones make up relatively small (usually <5 m) equant or elongate bodies and occur as fragments of larger bodies. These fragments are often concentrated in stripes. Metabasites in the gently sloping shear zone are sometimes also found as lenses and tabular bodies of relatively small thickness, which are conformable with the foliation of the host rocks. The gently sloping shear zones cut across older domains of more complicated structure, which suggests that these zones are gently sloping ductile shear zones. Along these zones, the nappes were thrust south- and southwestward, and this process was the last in the origin of major structural features of BMB when the Paleoproterozoic Lapland-Kola orogen was formed. Practically identical age values were obtained for the gently sloping shear zone in the two widely separated Engonozero and Chupa segments of BMB: 1879 ± 21 Ma (40Ar/39Ar amphibole age of amphibolite whose protolith was mafic rock) and 1857 ± 13 Ma (Sm-Nd mineral isochron age of garnet amphibolites after gabbronorite). The P- T metamorphic parameters in these gently sloping shear zones are remarkably different from the metamorphic parameters outside these zones: the pressure is 3-4 kbar lower and the temperature is 60-100°C lower. Thrusting-related decompression triggered the transition from the older high-pressure episode of Paleoproterozoic metamorphism to a younger syn-thrusting higher temperature metamorphic episode. The peak metamorphic parameters corresponding to the boundary between the amphibolite and

  13. Deformation behavior of SS400 Thick plate by high-frequency-induction-heating-based line heating

    NASA Astrophysics Data System (ADS)

    Lee, Kwang Seok; Eom, Deuk Ha; Lee, Jung-Hwan

    2013-03-01

    In this study, the line heating-induced permanent deformation behavior of an SS400 thick plate was investigated through both numerical analysis and experimental testing by applying high-frequency induction heating after generating dual-curvature by secondary line heating. First, an approach based on electromagnetic-thermal-structural coupling numerical analysis was adopted for predicting the temperature distribution and subsequent permanent deformation over the SS400 carbon steel plate. Experimental line heating was also carried out to validate the feasibility of the numerical analysis by applying newly designed laboratory-scale high-frequency (HF) induction-heating (IH) equipment. It was found that the shape of the heat-affected zone (HAZ) generated by HF IH and the subsequent microstructure of the SS400 carbon steel plate within the HAZ were strongly dependent on the input power. Permanent vertical deformation increased with an increase in the input power, regardless of the shape of the doubly curved plates (concave- or saddle-type plates). Transverse curvature determined in both the simulation and the experiment were investigated and compared.

  14. Genetic determinism of phenological traits highly affected by climate change in Prunus avium: flowering date dissected into chilling and heat requirements.

    PubMed

    Castède, Sophie; Campoy, José Antonio; García, José Quero; Le Dantec, Loïck; Lafargue, Maria; Barreneche, Teresa; Wenden, Bénédicte; Dirlewanger, Elisabeth

    2014-04-01

    The present study investigated the genetic determinism of flowering date (FD), dissected into chilling (CR) and heat (HR) requirements. Elucidation of the genetic determinism of flowering traits is crucial to anticipate the increasing of ecological misalignment of adaptative traits with novel climate conditions in most temperate-fruit species. CR and HR were evaluated over 3 yr and FD over 5 yr in an intraspecific sweet cherry (Prunus avium) F1 progeny, and FD over 6 yr in a different F1 progeny. One quantitative trait locus (QTL) with major effect and high stability between years of evaluation was detected for CR and FD in the same region of linkage group (LG) 4. For HR, no stable QTL was detected. Candidate genes underlying the major QTL on LG4 were investigated and key genes were identified for CR and FD. Phenotypic dissection of FD and year repetitions allowed us to identify CR as the high heritable component of FD and a high genotype × environment interaction for HR. QTLs for CR reported in this study are the first described in this species. Our results provide a foundation for the identification of genes involved in CR and FD in sweet cherry which could be used to develop ideotypes adapted to future climatic conditions.

  15. Heat accumulation during pulsed laser materials processing.

    PubMed

    Weber, Rudolf; Graf, Thomas; Berger, Peter; Onuseit, Volkher; Wiedenmann, Margit; Freitag, Christian; Feuer, Anne

    2014-05-05

    Laser materials processing with ultra-short pulses allows very precise and high quality results with a minimum extent of the thermally affected zone. However, with increasing average laser power and repetition rates the so-called heat accumulation effect becomes a considerable issue. The following discussion presents a comprehensive analytical treatment of multi-pulse processing and reveals the basic mechanisms of heat accumulation and its consequence for the resulting processing quality. The theoretical findings can explain the experimental results achieved when drilling microholes in CrNi-steel and for cutting of CFRP. As a consequence of the presented considerations, an estimate for the maximum applicable average power for ultra-shorts pulsed laser materials processing for a given pulse repetition rate is derived.

  16. 24 CFR 3280.506 - Heat loss/heat gain.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.506 Heat... assure uniform heat transmission in manufactured homes, cavities in exterior walls, floors, and ceilings shall be provided with thermal insulation. (c) Manufactured homes designed for Uo Value Zone 3 shall...

  17. Solar heated fluidized bed gasification system

    NASA Technical Reports Server (NTRS)

    Qader, S. A. (Inventor)

    1981-01-01

    A solar-powered fluidized bed gasification system for gasifying carbonaceous material is presented. The system includes a solar gasifier which is heated by fluidizing gas and steam. Energy to heat the gas and steam is supplied by a high heat capacity refractory honeycomb which surrounds the fluid bed reactor zone. The high heat capacity refractory honeycomb is heated by solar energy focused on the honeycomb by solar concentrator through solar window. The fluid bed reaction zone is also heated directly and uniformly by thermal contact of the high heat capacity ceramic honeycomb with the walls of the fluidized bed reactor. Provisions are also made for recovering and recycling catalysts used in the gasification process. Back-up furnace is provided for start-up procedures and for supplying heat to the fluid bed reaction zone when adequate supplies of solar energy are not available.

  18. BAY 81-8973, a full-length recombinant factor VIII: Human heat shock protein 70 improves the manufacturing process without affecting clinical safety.

    PubMed

    Maas Enriquez, Monika; Thrift, John; Garger, Stephen; Katterle, Yvonne

    2016-11-01

    BAY 81-8973 is a full-length, unmodified recombinant human factor VIII (FVIII) approved for the treatment of hemophilia A. BAY 81-8973 has the same amino acid sequence as the currently marketed sucrose-formulated recombinant FVIII (rFVIII-FS) product and is produced using additional advanced manufacturing technologies. One of the key manufacturing advances for BAY 81-8973 is introduction of the gene for human heat shock protein 70 (HSP70) into the rFVIII-FS cell line. HSP70 facilitates proper folding of proteins, enhances cell survival by inhibiting apoptosis, and potentially impacts rFVIII glycosylation. HSP70 expression in the BAY 81-8973 cell line along with other manufacturing advances resulted in a higher-producing cell line and improvements in the pharmacokinetics of the final product as determined in clinical studies. HSP70 protein is not detected in the harvest or in the final BAY 81-8973 product. However, because this is a new process, clinical trial safety assessments included monitoring for anti-HSP70 antibodies. Most patients, across all age groups, had low levels of anti-HSP70 antibodies before exposure to the investigational product. During BAY 81-8973 treatment, 5% of patients had sporadic increases in anti-HSP70 antibody levels above a predefined threshold (cutoff value, 239 ng/mL). No clinical symptoms related to anti-HSP70 antibody development occurred. In conclusion, addition of HSP70 to the BAY 81-8973 cell line is an innovative technology for manufacturing rFVIII aimed at improving protein folding and expression. Improved pharmacokinetics and no effect on safety of BAY 81-8973 were observed in clinical trials in patients with hemophilia A.

  19. Performance, egg quality traits, and serum metabolite concentrations of laying hens affected by dietary supplemental chromium picolinate and vitamin C under a heat-stress condition.

    PubMed

    Torki, Mehran; Zangeneh, Samira; Habibian, Mahmood

    2014-02-01

    A 3 × 2 factorial experiment consisting three levels (0, 200, and 400 μg/kg) of chromium (chromium picolinate) and two levels (0 and 250 mg/kg) of vitamin C was employed to evaluate the effects of these dietary supplements on performance, egg quality traits, and serum biochemical parameters of heat-stressed laying hens (Lohmann LSL-Lite) from 66 to 74 weeks of age. Feed intake increased when birds were given either 400 μg/kg chromium or 250 mg/kg vitamin C (P < 0.05), but the birds that received both chromium and vitamin C consumed feed similar to those that received only chromium. Dietary treatments had no effect on egg production, egg mass, egg volume, feed conversion ratio, and body mass (P > 0.05). The birds that fed on diet with chromium or vitamin C produced eggs with higher shell mass and thickness compared to the control. Both eggshell mass and thickness decreased when vitamin C and chromium were supplemented simultaneously, and birds given the diet supplemented with 400 μg/kg chromium and 250 mg/kg vitamin C had eggshell mass and thickness similar to those of the control group. The serum concentration of chromium increased due to increasing level of dietary chromium (P < 0.05). The birds that received diet with chromium and vitamin C had higher serum concentrations of chromium compared to those that received only chromium (P < 0.05). Similarly, the hens that received chromium and vitamin C had higher serum concentrations of calcium and phosphorus compared to the hens fed with other treatments (P < 0.05). The birds given with supplemental chromium exhibited lower serum glucose, total cholesterol, and triglycerides concentrations but higher serum albumin and total protein concentrations compared to the other groups (P < 0.05).

  20. Ovine HSP90AA1 Expression Rate Is Affected by Several SNPs at the Promoter under Both Basal and Heat Stress Conditions

    PubMed Central

    Salces-Ortiz, Judit; González, Carmen; Moreno-Sánchez, Natalia; Calvo, Jorge H.; Pérez-Guzmán, M. Dolores; Serrano, Magdalena M.

    2013-01-01

    The aim of this work was to investigate the association between polymorphisms located at the HSP90AA1 ovine gene promoter and gene expression rate under different environmental conditions, using a mixed model approach. Blood samples from 120 unrelated rams of the Manchega sheep breed were collected at three time points differing in environmental conditions. Rams were selected on the basis of their genotype for the transversion G/C located 660 base pairs upstream the gene transcription initiation site. Animals were also genotyped for another set of 6 SNPs located at the gene promoter. Two SNPs, G/C−660 and A/G−444, were associated with gene overexpression resulting from heat stress. The composed genotype CC−660-AG−444 was the genotype having the highest expression rates with fold changes ranging from 2.2 to 3.0. The genotype AG−522 showed the highest expression levels under control conditions with a fold change of 1.4. Under these conditions, the composed genotype CC−601-TT−524-AG−522-TT−468 is expected to be correlated with higher basal expression of the gene according to genotype frequencies and linkage disequilibrium values. Some putative transcription factors were predicted for binding sites where the SNPs considered are located. Since the expression rate of the gene under alternative environmental conditions seems to depend on the composed genotype of several SNPs located at its promoter, a cooperative regulation of the transcription of the HSP90AA1 gene could be hypothesized. Nevertheless epigenetic regulation mechanisms cannot be discarded. PMID:23826107

  1. Endogenous enzymes, heat, and pH affect flavone profiles in parsley (Petroselinum crispum var. neapolitanum) and celery (Apium graveolens) during juice processing.

    PubMed

    Hostetler, Gregory L; Riedl, Ken M; Schwartz, Steven J

    2012-01-11

    Flavones are abundant in parsley and celery and possess unique anti-inflammatory properties in vitro and in animal models. However, their bioavailability and bioactivity depend in part on the conjugation of sugars and other functional groups to the flavone core. The effects of juice extraction, acidification, thermal processing, and endogenous enzymes on flavone glycoside profile and concentration in both parsley and celery were investigated. Parsley yielded 72% juice with 64% of the total flavones extracted, whereas celery yielded 79% juice with 56% of flavones extracted. Fresh parsley juice averaged 281 mg flavones/100 g and fresh celery juice, 28.5 mg/100 g. Flavones in steamed parsley and celery were predominantly malonyl apiosylglucoside conjugates, whereas those in fresh samples were primarily apiosylglucoside conjugates; this was apparently the result of endogenous malonyl esterases. Acidification and thermal processing of celery converted flavone apiosylglucosides to flavone glucosides, which may affect the intestinal absorption and metabolism of these compounds.

  2. Effect of static and dynamic heat pain stimulus profiles on the temporal dynamics and interdependence of pain qualities, intensity, and affect.

    PubMed

    Hashmi, Javeria A; Davis, Karen D

    2008-10-01

    Acute and chronic pains are characterized by a particular constellation of pain qualities, such as burning, aching, stinging, or sharp feelings. However, the temporal pattern of specific pain qualities and their relationship with pain and affect is not well understood. In addition, little is known about how the temperature time course of the stimulus impacts the temporal dynamics of pain qualities and the relationship between pain qualities. Therefore we applied two types of stimuli to the feet of 16 healthy subjects, each calibrated to evoke a similar pain magnitude (50/100): static stimulus held at constant intensity and dynamic stimulus increased in intensity in small steps. Stimulus runs consisted of three 30-s stimuli (either static or dynamic) with an interstimulus interval of 60 s. Continuous on-line ratings of pain, burning, sharp, stinging, cutting, and annoyance were obtained in separate runs, and the evoked responses were characterized by within-stimulus adaptation (early: 0- to 15-s peak vs. late: 25- to 40-s peak) and by their temporal properties (time to onset, peak, and end). The temporal profile of the burning sensation was similar to the pain and annoyance evoked by the static and dynamic stimuli. However, the sharp, stinging and cutting sensations attenuated in response to the static stimuli (P<0.01) but intensified along with pain and affect in response to the dynamic stimuli (P<0.05), whereas there was no attenuation in the evoked profiles of pain (P=0.61), annoyance (P=0.27), or burning quality (P=0.27). These data demonstrate that specific pain qualities with known differences in underlying mechanisms have distinct temporal dynamics that depend on the stimulus intensity dynamics.

  3. IEA BESTEST Multi-Zone Non-Airflow In-Depth Diagnostic Cases: Preprint

    SciTech Connect

    Neymark, J.; Judkoff, R.; Alexander, D.; Felsmann, C.; Strachan, P.; Wijsman, A.

    2011-11-01

    This paper documents a set of in-depth diagnostic test cases for multi-zone heat transfer models that do not include the heat and mass transfer effects of airflow between zones. The multi-zone non-airflow test cases represent an extension to IEA BESTEST (Judkoff and Neymark 1995a).

  4. Effects of aging treatment and heat input on the microstructures and mechanical properties of TIG-welded 6061-T6 alloy joints

    NASA Astrophysics Data System (ADS)

    Peng, Dong; Shen, Jun; Tang, Qin; Wu, Cui-ping; Zhou, Yan-bing

    2013-03-01

    Aging treatment and various heat input conditions were adopted to investigate the microstructural evolution and mechanical properties of TIG welded 6061-T6 alloy joints by microstructural observations, microhardness tests, and tensile tests. With an increase in heat input, the width of the heat-affected zone (HAZ) increases and grains in the fusion zone (FZ) coarsen. Moreover, the hardness of the HAZ decreases, whereas that of the FZ decreases initially and then increases with an increase in heat input. Low heat input results in the low ultimate tensile strength of the welded joints due to the presence of partial penetrations and pores in the welded joints. After a simple artificial aging treatment at 175°C for 8 h, the microstructure of the welded joints changes slightly. The mechanical properties of the welded joints enhance significantly after the aging process as few precipitates distribute in the welded seam.

  5. Heat Islands

    EPA Pesticide Factsheets

    EPA's Heat Island Effect Site provides information on heat islands, their impacts, mitigation strategies, related research, a directory of heat island reduction initiatives in U.S. communities, and EPA's Heat Island Reduction Program.

  6. Inductively heated particulate matter filter regeneration control system

    SciTech Connect

    Gonze, Eugene V; Paratore Jr., Michael J; Kirby, Kevin W; Phelps, Amanda; Gregoire, Daniel J

    2012-10-23

    A system includes a particulate matter (PM) filter with an upstream end for receiving exhaust gas, a downstream end and zones. The system also includes a heating element. A control module selectively activates the heating element to inductively heat one of the zones.

  7. Climate change and dead zones.

    PubMed

    Altieri, Andrew H; Gedan, Keryn B

    2015-04-01

    Estuaries and coastal seas provide valuable ecosystem services but are particularly vulnerable to the co-occurring threats of climate change and oxygen-depleted dead zones. We analyzed the severity of climate change predicted for existing dead zones, and found that 94% of dead zones are in regions that will experience at least a 2 °C temperature increase by the end of the century. We then reviewed how climate change will exacerbate hypoxic conditions through oceanographic, ecological, and physiological processes. We found evidence that suggests numerous climate variables including temperature, ocean acidification, sea-level rise, precipitation, wind, and storm patterns will affect dead zones, and that each of those factors has the potential to act through multiple pathways on both oxygen availability and ecological responses to hypoxia. Given the variety and strength of the mechanisms by which climate change exacerbates hypoxia, and the rates at which climate is changing, we posit that climate change variables are contributing to the dead zone epidemic by acting synergistically with one another and with recognized anthropogenic triggers of hypoxia including eutrophication. This suggests that a multidisciplinary, integrated approach that considers the full range of climate variables is needed to track and potentially reverse the spread of dead zones.

  8. Prioritizing Healthcare Delivery in a Conflict Zone Comment on "TB/HIV Co-Infection Care in Conflict-Affected Settings: A Mapping of Health Facilities in the Goma Area, Democratic Republic of Congo".

    PubMed

    Wood, Robin; Richardson, Eugene T

    2013-09-01

    Nowhere are the barriers to a functional health infrastructure more clearly on display than in the Goma region of Democratic Republic of Congo. Kaboru et al. report poorly integrated services for HIV and TB in this war-torn region. Priorities in conflict zones include provision of security, shelter, food, clean water and prevention of sexual violence. In Goma, immediate health priorities include emergency treatment of cholera, malaria, respiratory illnesses, provision of maternal care, millions of measles vaccinations, and management of an ongoing rabies epidemic. It is a daunting task to determine an essential package of medical services in a setting where there are so many competing priorities, where opportunity costs are limited and epidemiologic information is scarce. Non-governmental agencies sometimes add to the challenge via an insidious reduction of state sovereignty and the creation of new levels of income inequality. Kaboru et al. have successfully highlighted many of the complexities of rebuilding and prioritizing healthcare in a conflict zone.

  9. Duration of a large Mafic intrusion and heat transfer in the lower crust: A SHRIMP U-Pb zircon Study in the Ivrea-Verbano Zone (Western Alps, Italy)

    USGS Publications Warehouse

    Peressini, G.; Quick, J.E.; Sinigoi, S.; Hofmann, A.W.; Fanning, M.

    2007-01-01

    The Ivrea-Verbano Zone in the western Italian Alps contains one of the world's classic examples of ponding of mantle-derived, mafic magma in the deep crust. Within it, a voluminous, composite mafic pluton, the Mafic Complex, intruded lower-crustal, high-grade paragneiss of the Kinzigite Formation during Permian-Carboniferous time, and is now exposed in cross-section as a result of Alpine uplift. The age of the intrusion is still debated because the results of geochronological studies in the last three decades on different rock types and with various dating techniques range from 250 to about 300 Ma. Sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon age determinations on 12 samples from several locations within the Mafic Complex were performed to better constrain the age of the igneous event. The results indicate a long history of magma emplacement and cooling, which reconciles the spread in previously published ages. The main intrusive phase took place at 288 ?? 4 Ma, causing a perturbation of the deep-crustal geotherm, which relaxed to the Sm-Nd closure temperature in garnet-free mafic rocks after about 15-20 Myr of sub-solidus cooling at c. 270 Ma. These results suggest that large, deep crustal plutons, such as those identified geophysically at depths of 10-20 km within extended continental crust (e.g. Yellowstone, Rio Grande Rift, Basin and Range) may have formed rapidly but induced a prolonged thermal perturbation. In addition, the data indicate that a significant thermal event affected the country rock of the Mafic Complex at about 310 Ma. The occurrence of an upper amphibolite- to granulite-facies thermal event in the Kinzigite Formation prior to the main intrusive phase of the Mafic Complex has been postulated by several workers, and is corroborated by other geochronological investigations. However, it remains uncertain whether this event (1) was part of a prolonged perturbation of the deep-crustal geotherm, which started long before the onset of

  10. Vulnerable Zone Indicator System (Option 2)

    EPA Pesticide Factsheets

    Enter your latitude and longitude to access the Vulnerable Zone Indicator System. VZIS can help you determine if your area could be affected by a chemical accident at a facility that submitted a Risk Management Plan (RMP).

  11. Solid oxide fuel cell systems with hot zones having improved reactant distribution

    DOEpatents

    Poshusta, Joseph C.; Booten, Charles W.; Martin, Jerry L.

    2012-11-06

    A Solid Oxide Fuel Cell (SOFC) system having a hot zone with a center cathode air feed tube for improved reactant distribution, a CPOX reactor attached at the anode feed end of the hot zone with a tail gas combustor at the opposing end for more uniform heat distribution, and a counter-flow heat exchanger for efficient heat retention.

  12. Solid oxide fuel cell systems with hot zones having improved reactant distribution

    DOEpatents

    Poshusta, Joseph C.; Booten, Charles W.; Martin, Jerry L.

    2016-05-17

    A Solid Oxide Fuel Cell (SOFC) system having a hot zone with a center cathode air feed tube for improved reactant distribution, a CPOX reactor attached at the anode feed end of the hot zone with a tail gas combustor at the opposing end for more uniform heat distribution, and a counter-flow heat exchanger for efficient heat retention.

  13. Solid oxide fuel cell systems with hot zones having improved reactant distribution

    DOEpatents

    Poshusta, Joseph C; Booten, Charles W; Martin, Jerry L

    2013-12-24

    A Solid Oxide Fuel Cell (SOFC) system having a hot zone with a center cathode air feed tube for improved reactant distribution, a CPOX reactor attached at the anode feed end of the hot zone with a tail gas combustor at the opposing end for more uniform heat distribution, and a counter-flow heat exchanger for efficient heat retention.

  14. Analysis of the impact of informative heat treatment parameters on the properties of hardening of the surface layers

    NASA Astrophysics Data System (ADS)

    Rakhimov, R. R.; Saubanov, Ruz R.; Israfilov, I. H.

    2017-01-01

    The change features of surface steel layer were investigated under influence of plasma source of concentrated energy. The results of research of the effect of plasma treatment process on the microstructure and the thickness distribution of microhardness of the product and the formation of heat affected zone were presented. The resulting information (informative) data and measured values of microhardness in the hardened layers, depending on the plasma processing modes allow you to manage the process of heat treatment of metals. Designed programming model that works on the basis of the solution of the heat equation, allows to predict and investigate the temperature field after exposure to the plasma stream.

  15. Contactless heater floating zone refining and crystal growth

    NASA Technical Reports Server (NTRS)

    Kou, Sindo (Inventor); Lan, Chung-Wen (Inventor)

    1993-01-01

    Floating zone refining or crystal growth is carried out by providing rapid relative rotation of a feed rod and finish rod while providing heat to the junction between the two rods so that significant forced convection occurs in the melt zone between the two rods. The forced convection distributes heat in the melt zone to allow the rods to be melted through with a much shorter melt zone length than possible utilizing conventional floating zone processes. One of the rods can be rotated with respect to the other, or both rods can be counter-rotated, with typical relative rotational speeds of the rods ranging from 200 revolutions per minute (RPM) to 400 RPM or greater. Zone refining or crystal growth is carried out by traversing the melt zone through the feed rod.

  16. Investigation of heat transfer and combustion in the advanced fluidized bed combustor (FBC)

    SciTech Connect

    Lee, S.W.

    1999-09-01

    This technical report summarizes the research conducted and progress achieved during the period from April 1, 1998 to June 30, 1998. The numerical simulation was continued to determine the concentration distribution of the gas species, heat flux and heat transfer coefficients in the hot combustor model. The different gas concentration profiles showed the gas mixing characteristics along the combustor height. The center zone of the combustor has a relatively high methane mass concentration. The injection of secondary air squeezes the uprising flue gas and methane that causes the fuel-lean zone near the secondary air nozzles. The carbon dioxide concentration increased with the increasing of the combustor height. The peak concentration of oxygen remains at the combustor wall because of the secondary injection. The heat flux on the wall of the upper chamber is much higher than that of the lower chamber. It is believed that the heat flux is affected by the designed strong swirl and secondary air injection. The heat transfer coefficient changes along the combustor height were also affected by the multiple secondary air injection. The numerical simulation results could verify the predictions of the experimental results. It is a quite similar trend of the heat transfer coefficient changes based on the combustion test results.

  17. Production from multiple zones of a tar sands formation

    DOEpatents

    Karanikas, John Michael; Vinegar, Harold J

    2013-02-26

    A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat is allowed to transfer from the heaters to at least a portion of the formation. Fluids are produced from the formation through at least one production well that is located in at least two zones in the formation. The first zone has an initial permeability of at least 1 darcy. The second zone has an initial of at most 0.1 darcy. The two zones are separated by a substantially impermeable barrier.

  18. Global analysis of the effect of fluid flow on subduction zone temperatures

    NASA Astrophysics Data System (ADS)

    Rotman, Holly M. M.; Spinelli, Glenn A.

    2013-08-01

    Knowledge of the controls on temperature distributions at subduction zones is critical for understanding a wide range of seismic, metamorphic, and magmatic processes. Here, we present the results of ˜220 thermal model simulations covering the majority of known subduction zone convergence rates, incoming plate ages, and slab dips. We quantify the thermal effects of fluid circulation in the subducting crust by comparing results with and without advective heat transfer in the oceanic crustal aquifer. We find that hydrothermal cooling of a subduction zone is maximized when the subducting slab is young, slowly converging, steeply dipping, and the crustal aquifer is ventilated near the trench. Incoming plate age is one of the primary controls on the effectiveness of advective heat transfer in the aquifer, and the greatest temperature effects occur with an incoming plate <50 Ma. The thermal effects of fluid circulation decrease dramatically with increasing age of the incoming plate. Temperatures in the Cascadia, Nankai, southern Chile, Colombia/Ecuador, Mexico, and Solomon Islands subduction zones are likely strongly affected by fluid circulation; for these systems, only thermal models of Cascadia and Nankai have included fluid flow in subducting crust.

  19. Tectonics and the photosynthetic habitable zone (Invited)

    NASA Astrophysics Data System (ADS)

    Sleep, N. H.

    2009-12-01

    The traditional habitable zone lies between an inner stellar radius where the surface of the planet becomes too hot for liquid water carbon-based life and on outer radius, where the surface freezes. It is effectively the zone where photosynthesis is feasible. The concept extends to putative life on objects with liquid methane at the surface, like Titan. As a practical matter, photosynthesis leaves detectable biosignatures in the geological record; black shale on the Earth indicates that sulfide and probably FeO based photosynthesis existed by 3.8 Ga. The hard crustal rocks and the mantle sequester numerous photosynthetic biosignatures. Photosynthesis can produce detectable free oxygen with ozone in the atmosphere of extrasolar planets. In contrast, there is no outer limit for subsurface life in large silicate objects. Pre-photosynthetic niches are dependable but meager and not very detectable at great antiquity or great distance, with global productivity less than 1e-3 of the photosynthetic ones. Photosynthetic organisms have bountiful energy that modifies their surface environment and even tectonics. For example, metamorphic rocks formed at the expense of thick black shale are highly radioactive and hence self-fluxing. Active tectonics with volcanism and metamorphism prevents volatiles from being sequestered in the subsurface as on Mars. A heat-pipe object, like a larger Io, differs from the Earth in that the volatiles return to the deep interior distributed within massive volcanic deposits rather than concentrated in the shallow oceanic crust. One the Earth, the return of water to the surface by arc volcanoes controls its mantle abundance at the transition between behaving as a trace element and behaving as a major element that affects melting. The ocean accumulates the water that the mantle and crust do not take. The Earth has the “right” amount of water that erosion/deposition and tectonics both tend to maintain near sea level surfaces. The mantle contains

  20. Browns Ferry waste heat greenhouse environmental control system design

    SciTech Connect

    Olszewski, M.; Stovall, T.K.; Hicks, N.G.; Pile, R.S.; Burns, E.R.; Waddell, E.L. Jr.

    1980-03-01

    Oak Ridge National Laboratory, Tennessee Valley Authority and the Environmental Research Laboratory at the University of Arizona cooperated on the design of an experimental greenhouse located at TVA's Browns Ferry Nuclear Generating Station. Two greenhouse zones are heated by waste heat from the plant's condenser effluent. For comparison, a third greenhouse zone is heated conventionally (fossil-fueled burners) as a control. Design specifics for each of the three zones and a qualitative operating evaluation are presented.

  1. Heat flow increase following the rise of mantle isotherms and crustal thinning

    NASA Technical Reports Server (NTRS)

    Mareschal, J. C.; Bergantz, G.

    1985-01-01

    Heat flow measurements in the western United States define a zone of high heat flow which coincides with the Basin and Range Province where extension has taken place recently. In this region, the average reduced heat flow is approx 30 mW sq. meters higher than in stable continental provinces; locally (e.g., Battle Mountain High), the heat flow anomaly can be more than 100 mW/sq meters above average. Estimates of the amount of extension range between 30% and 100% for the past 30 Ma. In the Colorado Plateau, which has been uplifted without major tectonic deformation, the heat flow is only slightly above average. Analytical calculations show that an abrupt change in heat flow at the base of the lithosphere 30 Ma ago would not affect the surface significantly. Uplift would proceed at a slow rate. A thermal perturbation at the base of a 40 km thick crust, however, would reach the surface faster and, after 30 Ma, the increase in surface heat flow would be about 75% of the amplitude of the heat flow anomaly. The number of volcanic rocks in the Basin and Range suggests that magma intrusions may provide an effective heat transfer mechanism. It can be show that if the source of the intrusions is at the base of the lithosphere, the response time will be much longer than 30 Ma, and most ot the heat transferred from the asthenosphere will be absorbed in the lithosphere.

  2. Heat pumps

    NASA Astrophysics Data System (ADS)

    Gilli, P. V.

    1982-11-01

    Heat pumps for residential/commercial space heating and hot tap water make use of free energy of direct or indirect solar heat and save from about 40 to about 70 percent of energy if compared to a conventional heating system with the same energy basis. In addition, the electrically driven compressor heat pump is able to substitute between 40% (bivalent alternative operation) to 100% (monovalent operation) of the fuel oil of an oilfired heating furnace. For average Central European conditions, solar space heating systems with high solar coverage factor show the following sequence of increasing cost effectiveness: pure solar systems (without heat pumps); heat pump assisted solar systems; solar assisted heat pump systems; subsoil/water heat pumps; air/water heat pumps; air/air heat pumps.

  3. Natural analogs for enhanced heat recovery from geothermal systems

    SciTech Connect

    Nielson, Dennis L.

    1996-01-24

    High-temperature hydrothermal systems are physically and chemically zoned with depth. The energy input is from a magmatic zone, intruded by igneous bodies, that may also contribute variable amounts of magmatic fluid to the system. The heat source is directly overlain by a section of rocks, that due to their elevated temperature, respond to stress in a ductile fashion. The ductile zone is, in turn, overlain by a section of rocks that respond to stress in a brittle fashion, where water is able to circulate through fractures (the geothermal reservoir) and will be termed the hydrothermal circulation zone. Ancient and modern high-temperature geothermal systems show a predictable sequence of evolutionary events affecting these stratified zones. Metamorphic core complexes are uplifts, formed in highly extended terrains, that expose fossil brittle-ductile transition zones. Formerly ductile rocks have had brittle fractures superimposed on them, and meteoric hydrothermal systems are associated with the brittle fracturing. Porphyry copper deposits typically evolve from magmatic to meteoric hydrothermal systems. At the Larderello geothermal system, the brittle- ductile transition has been mapped using reflection seismology, and the zone has been penetrated by the San Pompeo 2 well where temperatures >420°C were encountered. Although neo-granitic dikes have been penetrated by drilling in the Larderello area, the brittle- ductile transition is largely above the inferred plutonic heat source. In the Geysers system, in contrast, the present steam system has been superimposed on young plutonic rocks and the inferred brittle-ductile transition is present at a depth of about 4.7 km within the plutonic rocks. As hydrothermal reservoirs are depleted, or surface facilities are restricted by environmental considerations, interest will turn to the deeper portions of known systems. Japan already has an aggressive program to develop Deep-seated and Magma-Ambient resources. This program, as

  4. Proposed Injection into “Thief” Zone in EE-3

    SciTech Connect

    Potter, Robert M.; Grigsby, Charles O.

    1983-08-18

    This report seeks to understand the nature of the "thief" zone inside the EE-3 by pumping 150-200K gallons of heated water into that zone. The questions they seek to answer are; does the thief zone represent a potential danger to future operations in the form of earthquakes, aquifers, damage to equipment or tubulars, or require that it be sealed; is a connection into the the thief zone from EE-2 a disaster point; could the connection into the thief zone provide a low back-pressure condition.

  5. Heat Pipes

    ERIC Educational Resources Information Center

    Lewis, J.

    1975-01-01

    Describes the construction, function, and applications of heat pipes. Suggests using the heat pipe to teach principles related to heat transfer and gives sources for obtaining instructional kits for this purpose. (GS)

  6. Marginal Ice Zone: Biogeochemical Sampling with Gliders

    DTIC Science & Technology

    2013-09-30

    nutrient rich waters into the euphotic zone in supporting these blooms. 4. Evaluate the potential role of phytoplankton pigment absorption on the...vertical gradient of heating under the ice and apply a light and chlorophyll primary productivity model to estimate and compare phytoplankton ...melt and phytoplankton optical properties under Arctic ice. The project specific goals are to build collaboration with Arctic biogeochemists at

  7. Heat Capacity Analysis Report

    SciTech Connect

    A. Findikakis

    2004-11-01

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

  8. Beyond the classic thermoneutral zone: Including thermal comfort.

    PubMed

    Kingma, Boris Rm; Frijns, Arjan Jh; Schellen, Lisje; van Marken Lichtenbelt, Wouter D

    2014-01-01

    The thermoneutral zone is defined as the range of ambient temperatures where the body can maintain its core temperature solely through regulating dry heat loss, i.e., skin blood flow. A living body can only maintain its core temperature when heat production and heat loss are balanced. That means that heat transport from body core to skin must equal heat transport from skin to the environment. This study focuses on what combinations of core and skin temperature satisfy the biophysical requirements of being in the thermoneutral zone for humans. Moreover, consequences are considered of changes in insulation and adding restrictions such as thermal comfort (i.e. driver for thermal behavior). A biophysical model was developed that calculates heat transport within a body, taking into account metabolic heat production, tissue insulation, and heat distribution by blood flow and equates that to heat loss to the environment, considering skin temperature, ambient temperature and other physical parameters. The biophysical analysis shows that the steady-state ambient temperature range associated with the thermoneutral zone does not guarantee that the body is in thermal balance at basal metabolic rate per se. Instead, depending on the combination of core temperature, mean skin temperature and ambient temperature, the body may require significant increases in heat production or heat loss to maintain stable core temperature. Therefore, the definition of the thermoneutral zone might need to be reformulated. Furthermore, after adding restrictions on skin temperature for thermal comfort, the ambient temperature range associated with thermal comfort is smaller than the thermoneutral zone. This, assuming animals seek thermal comfort, suggests that thermal behavior may be initiated already before the boundaries of the thermoneutral zone are reached.

  9. Infrared nanosecond pulsed laser irradiation of stainless steel: Micro iron-oxide zones generation

    NASA Astrophysics Data System (ADS)

    Ortiz-Morales, M.; Frausto-Reyes, C.; Soto-Bernal, J. J.; Acosta-Ortiz, S. E.; Gonzalez-Mota, R.; Rosales-Candelas, I.

    2014-07-01

    Nanosecond-pulsed, infrared (1064 nm) laser irradiation was used to create periodic metal oxide coatings on the surface of two samples of commercial stainless steel at ambient conditions. A pattern of four different metal oxide zones was created using a galvanometer scanning head and a focused laser beam over each sample. This pattern is related to traverse direction of the laser beam scanning. Energy-dispersive X-ray spectroscopy (EDS) was used to find the elemental composition and Raman spectroscopy to characterize each oxide zone. Pulsed laser irradiation modified the composition of the stainless steel samples, affecting the concentration of the main components within each heat affected zone. The Raman spectra of the generated oxides have different intensity profiles, which suggest different oxide phases such as magnetite and maghemite. In addition, these oxides are not sensible to the laser power of the Raman system, as are the iron oxide powders reported in the literature. These experiments show that it is possible to generate periodic patterns of various iron oxide zones by laser irradiation, of stainless steel at ambient conditions, and that Raman spectroscopy is a useful punctual technique for the analysis and inspection of small oxide areas.

  10. Infrared nanosecond pulsed laser irradiation of stainless steel: micro iron-oxide zones generation.

    PubMed

    Ortiz-Morales, M; Frausto-Reyes, C; Soto-Bernal, J J; Acosta-Ortiz, S E; Gonzalez-Mota, R; Rosales-Candelas, I

    2014-07-15

    Nanosecond-pulsed, infrared (1064 nm) laser irradiation was used to create periodic metal oxide coatings on the surface of two samples of commercial stainless steel at ambient conditions. A pattern of four different metal oxide zones was created using a galvanometer scanning head and a focused laser beam over each sample. This pattern is related to traverse direction of the laser beam scanning. Energy-dispersive X-ray spectroscopy (EDS) was used to find the elemental composition and Raman spectroscopy to characterize each oxide zone. Pulsed laser irradiation modified the composition of the stainless steel samples, affecting the concentration of the main components within each heat affected zone. The Raman spectra of the generated oxides have different intensity profiles, which suggest different oxide phases such as magnetite and maghemite. In addition, these oxides are not sensible to the laser power of the Raman system, as are the iron oxide powders reported in the literature. These experiments show that it is possible to generate periodic patterns of various iron oxide zones by laser irradiation, of stainless steel at ambient conditions, and that Raman spectroscopy is a useful punctual technique for the analysis and inspection of small oxide areas.

  11. The effects of plate-bending-related aquifer thickening on temperatures in the Japan Trench subduction zone

    NASA Astrophysics Data System (ADS)

    Spinelli, G. A.

    2015-12-01

    Accurate subduction zone thermal models are necessary to understand a wide range of geophysical and geochemical processes, including: metamorphic reaction progress, mantle wedge hydration, and melt generation. For decades, plate convergence rate and subducting plate age and dip have been recognized as basic factors affecting subduction zone temperatures. Recent discoveries highlight the important effects of fluid circulation in oceanic lithosphere on subduction zone temperatures. However, there are contrasting hypotheses for the distribution of the regions within the oceanic lithosphere that host vigorous fluid circulation: one with a constant thickness aquifer extending both seaward and landward of the trench, one with an aquifer that thickens as it approaches the trench (due to bend-related faulting) but assumes vigorous fluid circulation only occurs prior to subduction, and a hybrid that considers both aquifer thickening seaward of the trench and continued circulation in the subducting plate. I examine the effects of bend-related aquifer thickening on temperatures within the Japan Trench subduction zone with a suite of thermal models. Kawada et al. [2014] hypothesize that plate-bending faults offshore northern Japan increase the thickness of the oceanic crustal aquifer, and therefore influence heat redistribution in the system. Existing models explore the effects of aquifer thickening on heat flux seaward of the trench, but they do not examine the effects of this process on temperatures within the subduction zone; additionally, they treat the aquifer seaward of the trench as completely isolated from the aquifer in the subducted plate. Here, I exploit the fact that aquifer thickening from the outer rise to the trench and continued fluid circulation in subducting crust are expected to produce distinct surface heat flux anomalies, in order to constrain the thermal effects of each process. I find the combinations of the amount of aquifer thickening and the degree of

  12. Regular satellite formation and evolution in a dead zone

    NASA Astrophysics Data System (ADS)

    Chen, Cheng; Martin, Rebecca G.

    2017-01-01

    The dead zone in a circumplanetary disk is a non-turbulent region at the disk midplane that is an ideal location for regular satellite formation. The lower viscosity in the dead zone allows small objects to accrete and grow. We model the evolution of a circumplanetary disk with a dead zone for a range of disk and dead zone parameters. We investigate how these affect the formation and subsequent evolution of regular satellites that form in the disk.

  13. South Pacific convergence zone and global scale circulations (Jul. 1987 - Jul. 1991). Observational and modeling studies of heat, moisture, precipitation, and global-scale circulation patterns (Jul. 1990 - Jul. 1993)

    NASA Technical Reports Server (NTRS)

    Vincent, Dayton G.; Robertson, Franklin R.

    1991-01-01

    Several research projects were worked on between August 1990 and May 1991. Topics covered included observational and modeling studies of relationships between tropical heat sources and subtropical jet streams, the intraseasonal (30 to 60 day) oscillation near the equator, and precipitation over tropical oceans. Current research activities and plans for the coming year are outlined.

  14. On post-weld heat treatment cracking in tig welded superalloy ATI 718Plus

    NASA Astrophysics Data System (ADS)

    Asala, G.; Ojo, O. A.

    The susceptibility of heat affected zone (HAZ) to cracking in Tungsten Inert Gas (TIG) welded Allvac 718Plus superalloy during post-weld heat treatment (PWHT) was studied. Contrary to the previously reported case of low heat input electron beam welded Allvac 718Plus, where HAZ cracking occurred during PWHT, the TIG welded alloy is crack-free after PWHT, notwithstanding the presence of similar micro-constituents that caused cracking in the low input weld. Accordingly, the formation of brittle HAZ intergranular micro-constituents may not be a sufficient factor to determine cracking propensity, the extent of heat input during welding may be another major factor that influences HAZ cracking during PWHT of the aerospace superalloy Allvac 718Plus.

  15. [Dynamics of Radioecological State of the Fresh-Water Ecosystems Affected by a Long-Term Impact from Nuclear Power Plant in the Frontiers of the Zone under Observation].

    PubMed

    Trapeznikov, A V; Trapeznikova, V N; Korjavin, A V

    2015-01-01

    The results of radioecological studies of six small rivers situated in the surveillance zone of the Beloyarskaya NPP (BNPP) and around the cooling pond of the power plant are presented. 21 radionuclides and the total α- and β-activity were studied in the main components of the aquatic ecosystems. It is shown that after the 1st and 2nd BN PP blocks decommissioning the content of 60Co and 137Cs in the Beloyarskoye storage pond water, sediments, fish fauna and macrophytes dropped tens and hundreds of times. The fundamental importance of this fact is that in a large range of time the aquatic ecosystem mechanism of self-purification from radionuclides is working due to radioactive substances decay as well as redistribution of radionuclides from water to other components, primarily to the sediments. Of 6 small rivers the maximum levels of radioactive substances is found in the river Olkhovka, which for several years has been subjected to the low-level radioactive water discharges from Beloyarskaya NPP. The radionuclide content in the main components of the aquatic ecosystems of the other five rivers studied after BNPP 47-year operation period corresponds to the regional background.

  16. Heat Rash

    MedlinePlus

    ... clear up the heat rash?Should I use diaper ointment on my child?What caused my heat rash?Should I stop exercising until the heat rash clears up?What is the best way to prevent heat rash? Last Updated: April 2014 This article was contributed by: familydoctor.org editorial staff Tags: ...

  17. Method for heating nongaseous carbonaceous material

    DOEpatents

    Lumpkin, Jr., Robert E.

    1978-01-01

    Nongaseous carbonaceous material is heated by a method comprising introducing tangentially a first stream containing a nongaseous carbonaceous material and carbon monoxide into a reaction zone; simultaneously and separately introducing a second stream containing oxygen into the reaction zone such that the oxygen enters the reaction zone away from the wall thereof and reacts with the first stream thereby producing a gaseous product and heating the nongaseous carbonaceous material; forming an outer spiralling vortex within the reaction zone to cause substantial separation of gases, including the gaseous product, from the nongaseous carbonaceous material; removing a third stream from the reaction zone containing the gaseous product which is substantially free of the nongaseous carbonaceous material before a major portion of the gaseous product can react with the nongaseous carbonaceous material; and removing a fourth stream containing the nongaseous carbonaceous material from the reaction zone.

  18. Structure and Evolution of Internally Heated Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Komacek, Thaddeus D.; Youdin, Andrew N.

    2015-11-01

    The transit radii of many close-in extrasolar giant planets, or "hot Jupiters," are systematically larger than those expected from models considering only cooling from an initial high-entropy state. Though these planets receive strong irradiation, with equilibrium temperatures of 1000-2500 Kelvin, the absorption of stellar incident flux in the upper atmosphere alone cannot explain these anomalous radii. More promising mechanisms involve irradiation-driven meteorological activity, which penetrates much deeper into the planet than direct stellar heating. This circulation can lead to large-scale mixing and downward transport of kinetic energy, both processes whereby a fraction of the stellar incident power is transported downwards to the interior of the planet. Here we consider how deposition of heat at different pressure levels or structural locations within a planet affects the resulting evolution. To do so, we run global gas giant evolutionary models with with the stellar structure code MESA including additional energy dissipation. We find that relatively shallow atmospheric heating alone can explain the transit radii of the hot Jupiter sample, but heating in the convective zone is an order of magnitude more efficient regardless of exact location. Additionally, a small difference in atmospheric heating location can have a significant effect on radius evolution, especially near the radiative-convective boundary. The most efficient location to heat the planet is at the radiative-convective boundary or deeper. We expect that shear instabilities at this interface may naturally explain energy dissipation at the radiative-convective boundary, which typically lies at a pressure of ~1 kilobar after 5 Gyr for a planet with the mass and incident stellar flux of HD 209458b. Hence, atmospheric processes are most efficient at explaining the bloated radii of hot Jupiters if they can transport incident stellar power downwards to the top of the inner convective zone.

  19. Residential Variable-Capacity Heat Pumps Sized to Heating Loads

    SciTech Connect

    Munk, Jeffrey D.; Jackson, Roderick K.; Odukomaiya, Adewale; Gehl, Anthony C.

    2014-01-01

    Variable capacity heat pumps are an emerging technology offering significant energy savings potential and improved efficiency. With conventional single-speed systems, it is important to appropriately size heat pumps for the cooling load as over-sizing would result in cycling and insufficient latent capacity required for humidity control. These appropriately sized systems are often under-sized for the heating load and require inefficient supplemental electric resistance heat to meet the heating demand. Variable capacity heat pumps address these shortcomings by providing an opportunity to intentionally size systems for the dominant heating season load without adverse effects of cycling or insufficient dehumidification in the cooling season. This intentionally-sized system could result in significant energy savings in the heating season, as the need for inefficient supplemental electric resistance heat is drastically reduced. This is a continuation of a study evaluating the energy consumption of variable capacity heat pumps installed in two unoccupied research homes in Farragut, a suburb of Knoxville, Tennessee. In this particular study, space conditioning systems are intentionally sized for the heating season loads to provide an opportunity to understand and evaluate the impact this would have on electric resistance heat use and dehumidification. The results and conclusions drawn through this research are valid and specific for portions of the Southeastern and Midwestern United States falling in the mixed-humid climate zone. While other regions in the U.S. do not experience this type of climate, this work provides a basis for, and can help understand the implications of other climate zones on residential space conditioning energy consumption. The data presented here will provide a framework for fine tuning residential building EnergyPlus models that are being developed.

  20. NEP heat pipe radiators. [Nuclear Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Ernst, D. M.

    1979-01-01

    This paper covers improvements of heat pipe radiators for the thermionic NEP design. Liquid metal heat pipes are suitable as spacecraft radiator elements because of high thermal conductance, low mass and reliability, but the NEP thermionic system design was too large and difficult to fabricate. The current integral collector-radiator design consisting of several layers of thermionic converters, the annular-tangential collector heat pipe, the radiator heat pipe, and the transition zone designed to minimize the temperature difference between the collector heat pipe and radiator heat pipe are described. Finally, the design of micrometeoroid armor protection and the fabrication of the stainless steel annular heat pipe with a tangential arm are discussed, and it is concluded that the heat rejection system for the thermionic NEP system is well advanced, but the collector-radiator heat pipe transition and the 8 to 10 m radiator heat pipe with two bends require evaluation.

  1. Conservation of the Red Kite Milvus milvus (Aves: Accipitriformes) Is Not Affected by the Establishment of a Broad Hybrid Zone with the Black Kite Milvus migrans migrans in Central Europe

    PubMed Central

    Matušík, Hynek; Pfeiffer, Thomas; Nachtigall, Winfried; Bizos, Jiří; Šimčíková, Daniela; Literák, Ivan

    2016-01-01

    Among Accipitriformes sensu stricto, only a few species have been reported to form hybrid zones; these include the red kite Milvus milvus and black kite Milvus migrans migrans. M. milvus is endemic to the western Palearctic and has an estimated total population of 20–24,000 breeding pairs. The species was in decline until the 1970s due to persecution and has declined again since the 1990s due to ingestion of rodenticide-treated baits, illegal poisoning and changes in agricultural practices, particularly in its core range. Whereas F1 M. milvus × M. migr. migrans hybrid offspring have been found, F2 and F3 hybrids have only rarely been reported, with low nesting success rates of F1 hybrids and partial hybrid sterility likely playing a role. Here, we analyzed the mitochondrial (CO1 and CytB) and nuclear (Myc) DNA loci of 184 M. milvus, 124 M. migr. migrans and 3 F1 hybrid individuals collected across central Europe. In agreement with previous studies, we found low heterozygosity in M. milvus regardless of locus. We found that populations of both examined species were characterized by a high gene flow within populations, with all of the major haplotypes distributed across the entire examined area. Few haplotypes displayed statistically significant aggregation in one region over another. We did not find mitochondrial DNA of one species in individuals with the plumage of the other species, except in F1 hybrids, which agrees with Haldane´s Rule. It remains to be investigated by genomic methods whether occasional gene flow occurs through the paternal line, as the examined Myc gene displayed only marginal divergence between M. milvus and M. migr. migrans. The central European population of M. milvus is clearly subject to free intraspecific gene flow, which has direct implications when considering the origin of individuals in M. milvus re-introduction programs. PMID:27463515

  2. Differences in the Ovine HSP90AA1 Gene Expression Rates Caused by Two Linked Polymorphisms at Its Promoter Affect Rams Sperm DNA Fragmentation under Environmental Heat Stress Conditions

    PubMed Central

    González, Carmen; Pérez-Guzmán, M. Dolores; Garde, J. Julián; García-Álvarez, Olga; Maroto-Morales, Alejandro; Calvo, Jorge H.; Serrano, M. Magdalena

    2015-01-01

    Heat shock (HS) is one of the best-studied exogenous cellular stresses. Almost all tissues, cell types, metabolic pathways and biochemical reactions are affected in greater or lesser extent by HS. However, there are some especially thermo sensible cellular types such as the mammalian male germ cells. The present study examined the role of three INDELs in conjunction with the -660G/C polymorphism located at the HSP90AA1 promoter region over the gene expression rate under HS. Specially, the -668insC INDEL, which is very close to the -660G/C transversion, is a good candidate to be implied in the transcriptional regulation of the gene by itself or in a cooperative way with this SNP. Animals carrying the genotype II-668 showed higher transcription rates than those with ID-668 (FC = 3.07) and DD-668 (FC = 3.40) genotypes for samples collected under HS. A linkage between gene expression and sperm DNA fragmentation was also found. When HS conditions were present along or in some stages of the spermatogenesis, alternative genotypes of the -668insC and -660G/C mutations are involved in the effect of HS over sperm DNA fragmentation. Thus, unfavorable genotypes in terms of gene expression induction (ID-668GC-660 and DD-668GG-660) do not produce enough mRNA (stored as messenger ribonucleoprotein particles) and Hsp90α protein to cope with future thermal stress which might occur in posterior stages when transcriptional activity is reduced and cell types and molecular processes are more sensible to heat (spermatocytes in pachytene and spermatids protamination). This would result in the impairment of DNA packaging and the consequent commitment of the events occurring shortly after fertilization and during embryonic development. In the short-term, the assessment of the relationship between sperm DNA fragmentation sensitivity and ram’s fertility will be of interest to a better understanding of the mechanisms of response to HS and its consequences on animal production and

  3. Heat flow in Oklahoma

    NASA Astrophysics Data System (ADS)

    Cranganu, Constantin

    Twenty new heat flow values are incorporated, along with 40 previously published data, into a heat flow map of Oklahoma. The new heat flow data were estimated using previous temperature measurements in boreholes made by American Petroleum Institute researchers and 1,498 thermal conductivity measurements on drill cuttings. The mean of 20 average thermal gradients is 30.50sp°C/km. In general, thermal gradients increase from SW (14.11sp°C/km) to NE (42.24sp°C/km). The range of 1,498 in situ thermal conductivity measurements (after corrections for anisotropy, in situ temperature, and porosity) is 0.90-6.1 W/m-K; the average is 1.68 W/m-K. Estimated near-surface heat flow (±20%) at 20 new sites in Oklahoma varies between 22 ± 4 mW/msp2 and 86 ± 17 mW/msp2; the average is 50 mW/msp2. Twenty-seven new heat-generation estimates, along with 22 previously published data, are used to create a heat generation map of Oklahoma. The range of heat production estimates is 1.1-3.5 muW/msp3, with an average of 2.5 muW/msp3. The heat flow regime in Oklahoma is primarily conductive in nature, except for a zone in northeast. Transient effects due to sedimentary processes and metamorphic/igneous activity, as well as past climatic changes, do not significantly influence the thermal state of the Oklahoma crust. Heat flow near the margins of the Arkoma and Anadarko Basins may be depressed or elevated by 5-13 mW/msp2 by refraction of heat from sedimentary rocks of relatively low thermal conductivity (1-2 W/m-K) into crystalline basement rocks of relatively high thermal conductivity (˜3-4 W/m-K). The heat generation-heat flow relationship shows a modest correlation. The relatively high heat flow (˜70-80 mW/msp2) in part of northeastern Oklahoma suggests that the thermal regime there may be perturbed by regional groundwater flow originating in the fractured outcrops of the Arbuckle-Simpson aquifer in the Arbuckle Mountains.

  4. Coastal Zone Color Scanner

    NASA Technical Reports Server (NTRS)

    Johnson, B.

    1988-01-01

    The Coastal Zone Color Scanner (CZCS) spacecraft ocean color instrument is capable of measuring and mapping global ocean surface chlorophyll concentration. It is a scanning radiometer with multiband capability. With new electronics and some mechanical, and optical re-work, it probably can be made flight worthy. Some additional components of a second flight model are also available. An engineering study and further tests are necessary to determine exactly what effort is required to properly prepare the instrument for spaceflight and the nature of interfaces to prospective spacecraft. The CZCS provides operational instrument capability for monitoring of ocean productivity and currents. It could be a simple, low cost alternative to developing new instruments for ocean color imaging. Researchers have determined that with global ocean color data they can: specify quantitatively the role of oceans in the global carbon cycle and other major biogeochemical cycles; determine the magnitude and variability of annual primary production by marine phytoplankton on a global scale; understand the fate of fluvial nutrients and their possible affect on carbon budgets; elucidate the coupling mechanism between upwelling and large scale patterns in ocean basins; answer questions concerning the large scale distribution and timing of spring blooms in the global ocean; acquire a better understanding of the processes associated with mixing along the edge of eddies, coastal currents, western boundary currents, etc., and acquire global data on marine optical properties.

  5. Effect of heat input on cracking in laser solid formed DZ4125 superalloy

    NASA Astrophysics Data System (ADS)

    Hu, Y. L.; Lin, X.; Song, K.; Jiang, X. Y.; Yang, H. O.; Huang, W. D.

    2016-12-01

    DZ4125 superalloy, which processes a high hot cracking sensitivity, is deposited on an as-cast substrate using laser solid forming (LSF) in order to investigate the effect of heat input on the cracking in the deposit and the heat affected zone (HAZ) in the substrate. It is shown that the liquation cracks occurred in LSFed sample with the lower heat input. The propagation extent of the cracks can be reduced with increasing the heat input. The crack-free deposits are achieved when the heat input reaches 150 J/mm. The variation of the residual stress in the LSFed sample with the heat input are discussed based on the micro-indentation analysis. It can be found that the elimination of the cracks with the high heat input can be attributed to the lower temperature gradient and thermal stresses in the LSFed sample. Besides, the backfilling of the liquid melt from the molten pool to the crack is also observed with the high heat input, which is also beneficial to the healing of crack in the HAZ of the molten pool.

  6. Two-Zone Bridgman Furnace With Sharp Thermal Gradient

    NASA Technical Reports Server (NTRS)

    Borshchevsky, Alex; Caillat, Thierry; Fleurial, Jean-Pierre

    1994-01-01

    Two-zone vertical directional-solidification furnace designed and built to grow crystals from stoichiometric and nonstoichiometric melts and from solutions. Includes conventional wire heater in lower zone, tubular silicon carbide heating element in upper zone, and thermal baffle between zones. Temperature gradients up to 125 degrees centigrade per centimeter achieved in the crystal-growth region. Sharper gradient enables both faster growth and better separation between solid and liquid. Furnace used in laboratory or industrial setting for growth of crystals from congruently melting materials as well as for growth of compounds formed by peritectic reactions.

  7. A six-zone simulation model for HCCI engines with a non-segregated solver of zone state

    NASA Astrophysics Data System (ADS)

    Kozarac, Darko; Lulic, Zoran; Sagi, Goran

    2010-07-01

    A new six-zone simulation model for the calculation of changes in an HCCI engine has been developed and tested. The model uses comprehensive chemical kinetics and a non-sequential solver of zone states. This means that the state vector comprises the states in all zones, and that the changes in states in all zones are calculated simultaneously. In this manner, physical accuracy during the calculation of a new state is maintained at the expense of the calculation time. The model comprises the wall heat transfer, zone heat transfer and zone mass transfer as means of zone interactions. The cylinder is divided into two central zones, three boundary layer zones and one crevice zone. Since the model calculates only the high pressure part of an engine cycle, it has been connected with the cycle simulation software AVL Boost. In this way, a relatively easy-to-use, higher accuracy, simulation tool for HCCI engines has been obtained. The model was tested by comparing simulation results with experimental ones. The comparison was made with a single cylinder engine running on isooctane. The calculated pressure and net rate of heat release correspond to the experimental results very well in the entire operating region. By using the six-zone simulation model, a big improvement, compared to the single zone simulation, is obtained in operating points where combustion efficiency is over 90%. Results of emissions of unburned HC and CO show that predictions of these species are greatly improved, but it has also been noticed that these emissions are still slightly underpredicted. Predictions of emissions that come from crevice regions are good, but emissions that come from the corners of boundary layers are not captured very well. A detailed description of the simulation model is given, and validation results and possibilities of a further development are discussed.

  8. High performance flexible heat pipes

    NASA Technical Reports Server (NTRS)

    Shaubach, R. M.; Gernert, N. J.

    1985-01-01

    A Phase I SBIR NASA program for developing and demonstrating high-performance flexible heat pipes for use in the thermal management of spacecraft is examined. The program combines several technologies such as flexible screen arteries and high-performance circumferential distribution wicks within an envelope which is flexible in the adiabatic heat transport zone. The first six months of work during which the Phase I contract goal were met, are described. Consideration is given to the heat-pipe performance requirements. A preliminary evaluation shows that the power requirement for Phase II of the program is 30.5 kilowatt meters at an operating temperature from 0 to 100 C.

  9. Heat Illness

    MedlinePlus

    ... symptoms include heavy sweating, rapid breathing and a fast, weak pulse Heat cramps - muscle pains or spasms that happen during heavy exercise Heat rash - skin irritation from excessive sweating Centers for Disease Control and Prevention

  10. Heat Stress

    MedlinePlus

    ... Stress Learn some tips to protect workers including: acclimatization, rest breaks, and fluid recommendations. NIOSH Workplace Solution: ... Blog: Adjusting to Work in the Heat: Why Acclimatization Matters The natural adaptation to the heat takes ...

  11. Extreme Heat

    MedlinePlus

    ... Emergencies Biological Threats Chemical Threats Cyber Incident Drought Earthquakes Extreme Heat Explosions Floods Hazardous Materials Incidents Home ... Emergencies Biological Threats Chemical Threats Cyber ... Heat Explosions Floods Hazardous Materials Incidents Home ...

  12. Heat Shield in Pieces

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This image from NASA's Mars Exploration Rover Opportunity shows the remains of the rover's heat shield, broken into two key pieces, the main piece on the left side and a broken-off flank piece near the middle of the image. The heat shield impact site is identified by the circle of red dust on the right side of the picture. In this view, Opportunity is approximately 20 meters (66 feet) away from the heat shield, which protected it while hurtling through the martian atmosphere.

    In the far left of the image, a meteorite called 'Heat Shield Rock,' sits nearby, The Sun is reflecting off the silver-colored underside of the internal thermal blankets of the heat shield.

    The rover spent 36 sols investigating how the severe heating during entry through the atmosphere affected the heat shield. The most obvious is the fact that the heat shield inverted upon impact.

    This is an approximately true-color rendering of the scene acquired around 1:22 p.m. local solar time on Opportunity sol 324 (Dec. 21, 2004) in an image mosaic using panoramic filters at wavelengths of 750, 530, and 430 nanometers.

  13. New Madrid Seismic Zone

    DTIC Science & Technology

    2007-11-02

    NEW MADRID SEISMIC ZONE BY COLONEL J.DAVID NORWOOD United States Army DISTRIBUTION STATEMENT A...mCTBB l USAWC STRATEGY RESEARCH PROJECT New Madrid Seismic Zone by J. David Norwood, COL, USA Michael A. Pearson, COL, USA Project Advisor The...ABSTRACT AUTHOR: J. David Norwood, Colonel, U.S. Army TITLE: New Madrid Seismic Zone FORMAT: Strategy Research Project DATE: 22 April 1998 . PAGES:

  14. Heat exchanger

    DOEpatents

    Daman, Ernest L.; McCallister, Robert A.

    1979-01-01

    A heat exchanger is provided having first and second fluid chambers for passing primary and secondary fluids. The chambers are spaced apart and have heat pipes extending from inside one chamber to inside the other chamber. A third chamber is provided for passing a purge fluid, and the heat pipe portion between the first and second chambers lies within the third chamber.

  15. Heat balance of the Earth

    NASA Technical Reports Server (NTRS)

    Budyko, M. I.; Berlyand, T. G.; Yefimova, N. A.; Zubenok, L. I.; Strokina, L. A.

    1980-01-01

    Results of improved calculations of the heat balance components of Earth's surface are reported for yearly average conditions. The technique used to determine the heat-balance components from land- and sea-based actinometric observations as well as from satellite data on the radiation balance of the Earth-atmosphere system is described, with special attention given to short-wavelength solar radiation on the continents, effective radiation from the land surface, the radiation balance of the ocean surface, heat expended by both evaporation from the ocean surface, and turbulent heat transfer between the ocean surface and the atmosphere. World maps of heat-balance components show yearly average values of total radiation, radiation balance, heat expended by evaporation, the turbulent heat flow between Earth's surface and atmosphere, and heat transfer between the ocean surface and underlying waters. The global surface heat balance is estimated along with global values of the various components and the heat-balance components for different latitude zones.

  16. Heat Pipes

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Heat Pipes were originally developed by NASA and the Los Alamos Scientific Laboratory during the 1960s to dissipate excessive heat build- up in critical areas of spacecraft and maintain even temperatures of satellites. Heat pipes are tubular devices where a working fluid alternately evaporates and condenses, transferring heat from one region of the tube to another. KONA Corporation refined and applied the same technology to solve complex heating requirements of hot runner systems in injection molds. KONA Hot Runner Systems are used throughout the plastics industry for products ranging in size from tiny medical devices to large single cavity automobile bumpers and instrument panels.

  17. Shear heating and clumped isotope reordering in carbonate faults

    NASA Astrophysics Data System (ADS)

    Siman-Tov, Shalev; Affek, Hagit P.; Matthews, Alan; Aharonov, Einat; Reches, Ze'ev

    2016-07-01

    Natural faults are expected to heat rapidly during seismic slip and to cool quite quickly after the slip event. Here we examine clumped isotope thermometry for its ability to identify such short duration elevated temperature events along frictionally heated carbonate faults. Our approach is based on measured Δ47 values that reflect the distribution of oxygen and carbon isotopes in the calcite lattice, measuring the abundance of 13Csbnd 18O bonds, which is affected by temperature. We examine three types of calcite rock samples: (1) crushed limestone grains that were rapidly heated and then cooled in static laboratory experiments, simulating the temperature cycle experienced by fault rock during an earthquake slip; (2) limestone samples that were experimentally sheared to simulate earthquake slip events; and (3) samples from Fault Mirrors (FMs) collected from principle slip surfaces of three natural carbonate faults. Extensive FM surfaces are believed to form during earthquake slip. Our experimental results show that Δ47 values decrease rapidly (in the course of seconds) with increasing temperature and shear velocity. On the other hand, carbonate shear zones from natural faults do not show such Δ47 decrease. We suggest that the Δ47 response may be controlled by nano-size grains, the high abundance of defects, and highly stressed/strained grain boundaries within the carbonate fault zone that can reduce the activation energy for diffusion, and thus lead to an increased rate of isotopic disordering during shear experiments. In our laboratory experiments the high stress and strain on grain contacts and the presence of nanograins thus allows for rapid disordering so that a change in Δ47 occurs in a very short and relatively low intensity heating events. In natural faults it may also lead to isotopic ordering after the cessation of frictional heating thus erasing the high temperature signature of Δ47.

  18. Fluidized bed heating process and apparatus

    NASA Technical Reports Server (NTRS)

    McHale, Edward J. (Inventor)

    1981-01-01

    Capacitive electrical heating of a fluidized bed enables the individual solid particles within the bed to constitute the hottest portion thereof. This effect is achieved by applying an A. C. voltage potential between dielectric coated electrodes, one of which is advantageously the wall of the fluidized bed rejection zone, sufficient to create electrical currents in said particles so as to dissipate heat therein. In the decomposition of silane or halosilanes in a fluidized bed reaction zone, such heating enhances the desired deposition of silicon product on the surface of the seed particles within the fluidized bed and minimizes undesired coating of silicon on the wall of the reaction zone and the homogeneous formation of fine silicon powder within said zone.

  19. Fault zone hydrogeologic properties and processes revealed by borehole temperature monitoring

    NASA Astrophysics Data System (ADS)

    Fulton, P. M.; Brodsky, E. E.

    2015-12-01

    High-resolution borehole temperature monitoring can provide valuable insight into the hydrogeologic structure of fault zones and transient processes that affect fault zone stability. Here we report on results from a subseafloor temperature observatory within the Japan Trench plate boundary fault. In our efforts to interpret this unusual dataset, we have developed several new methods for probing hydrogeologic properties and processes. We illustrate how spatial variations in the thermal recovery of the borehole after drilling and other spectral characteristics provide a measure of the subsurface permeability architecture. More permeable zones allow for greater infiltration of cool drilling fluids, are more greatly thermally disturbed, and take longer to recover. The results from the JFAST (Japan Trench Fast Drilling Project) observatory are consistent with geophysical logs, core data, and other hydrologic observations and suggest a permeable damage zone consisting of steeply dipping faults and fractures overlays a low-permeability clay-rich plate boundary fault. Using high-resolution time series data, we have also developed methods to map out when and where fluid advection occurs in the subsurface over time. In the JFAST data, these techniques reveal dozens of transient earthquake-driven fluid pulses that are spatially correlated and consistently located around inferred permeable areas of the fault damage zone. These observations are suspected to reflect transient fluid flow driven by pore pressure changes in response to dynamic and/or static stresses associated with nearby earthquakes. This newly recognized hydrologic phenomenon has implications for understanding subduction zone heat and chemical transport as well as the redistribution of pore fluid pressure which influences fault stability and can trigger other earthquakes.

  20. A multi-zone muffle furnace design

    NASA Technical Reports Server (NTRS)

    Rowe, Neil D.; Kisel, Martin

    1993-01-01

    A Multi-Zone Muffle-Tube Furnace was designed, built, and tested for the purpose of providing an in-house experience base with tubular furnaces for materials processing in microgravity. As such, it must not only provide the desired temperatures and controlled thermal gradients at several discrete zones along its length but must also be capable of sustaining the rigors of a Space Shuttle launch. The furnace is insulated to minimize radial and axial heat losses. It is contained in a water-cooled enclosure for purposes of dissipating un-wanted residual heat, keeping the outer surfaces of the furnace at a 'touch-safe' temperature, and providing a rugged housing. This report describes the salient features of the furnace, testing procedures and results, and concluding remarks evaluating the overall design.

  1. Effect of Heat Input on Microstructural Changes and Corrosion Behavior of Commercially Pure Titanium Welds in Nitric Acid Medium

    NASA Astrophysics Data System (ADS)

    Ravi Shankar, A.; Gopalakrishnan, G.; Balusamy, V.; Kamachi Mudali, U.

    2009-11-01

    Commercially pure titanium (Ti) has been selected for the fabrication of dissolver for the proposed fast reactor fuel reprocessing plant at Kalpakkam, India. In the present investigation, microstructural changes and corrosion behavior of tungsten inert gas (TIG) welds of Ti grade-1 and grade-2 with different heat inputs were carried out. A wider heat affected zone was observed with higher heat inputs and coarse grains were observed from base metal toward the weld zone with increasing heat input. Fine and more equiaxed prior β grains were observed at lower heat input and the grain size increased toward fusion zone. The results indicated that Ti grade-1 and grade-2 with different heat inputs and different microstructures were insensitive to corrosion in liquid, vapor, and condensate phases of 11.5 M nitric acid tested up to 240 h. The corrosion rate in boiling liquid phase (0.60-0.76 mm/year) was higher than that in vapor (0.012-0.039 mm/year) and condensate phases (0.04-0.12 mm/year) of nitric acid for Ti grade-1 and grade-2, as well as for base metal for all heat inputs. Potentiodynamic polarization experiment carried out at room temperature indicated higher current densities and better passivation in 11.5 M nitric acid. SEM examination of Ti grade-1 welds for all heat inputs exposed to liquid phase after 240 h showed corrosion attack on the surface, exposing Widmanstatten microstructure containing acicular alpha. The continuous dissolution of the liquid-exposed samples was attributed to the heterogeneous microstructure and non-protective passive film formation.

  2. Marginal Zone Lymphoma

    MedlinePlus

    ... zone lymphomas are a group of indolent (slow-growing) NHL B-cell lymphomas, which account for approximately 12 percent of all B-cell lymphomas. The median age for diagnosis is 65 years old. There are three types of marginal zone lymphoma: ...

  3. Urban Terrain Zone Characteristics

    DTIC Science & Technology