WorldWideScience

Sample records for ground thermal regime

  1. Snowpack redistribution, vegetation feedbacks, and advective heat transport controls on ground thermal regimes and hydrologic response in zero-order hillslope drainage features

    Science.gov (United States)

    Rushlow, C. R.; Godsey, S.; Sawyer, A. H.

    2017-12-01

    The impact of intensification of the Arctic hydrologic cycle depends on regional and local changes in precipitation, evaporation, and ground thaw. Upland Arctic hillslope hydrology may differ from responses in other Arctic systems because of changes in hydrologic connectivity and ground thermal response to warming. Here we examine hydrologic and ground thermal patterns from six zero-order hillslope features called water tracks on Alaska's North Slope. We find that water tracks' hydrologic response is slower than that of nearby streams and rivers, suggesting that water tracks are responsible for the prolonged summer flood response in larger water bodies rather than the immediate post-storm response as previously expected. We also compare non-water track hillslope and water track ground thermal regimes, and in contrast to water tracks in the High Arctic, we find that the upland water tracks thaw more deeply than non-track hillslope, and remain thawed for up to two months longer than hillslope soils in the winter. Finally, we use the multi-phase model SUTRA-ICE to examine the relative roles of varying winter snowpack thickness, vegetation feedbacks on ground thermal characteristics, and advective heat transport on the observed ground thermal regimes. Wind redistributes snow from non-track hillslopes into water tracks because of slight topographic depressions and differences in vegetation characteristics in the water tracks. These deeper snowpacks can better insulate the ground from cold winter air temperatures. Past work has suggested that advective heat transport in Arctic systems is minimal because of low hydraulic conductivity below a shallow organic soil horizon. However, we explore whether the persistence of flows for weeks or months longer in water tracks than non-track hillslopes may lead to significant advective heat transport in these systems.

  2. Envisioning, quantifying, and managing thermal regimes on river networks

    Science.gov (United States)

    Steel, E. Ashley; Beechie, Timothy J.; Torgersen, Christian; Fullerton, Aimee H.

    2017-01-01

    Water temperatures fluctuate in time and space, creating diverse thermal regimes on river networks. Temporal variability in these thermal landscapes has important biological and ecological consequences because of nonlinearities in physiological reactions; spatial diversity in thermal landscapes provides aquatic organisms with options to maximize growth and survival. However, human activities and climate change threaten to alter the dynamics of riverine thermal regimes. New data and tools can identify particular facets of the thermal landscape that describe ecological and management concerns and that are linked to human actions. The emerging complexity of thermal landscapes demands innovations in communication, opens the door to exciting research opportunities on the human impacts to and biological consequences of thermal variability, suggests improvements in monitoring programs to better capture empirical patterns, provides a framework for suites of actions to restore and protect the natural processes that drive thermal complexity, and indicates opportunities for better managing thermal landscapes.

  3. Vegetation management with fire modifies peatland soil thermal regime.

    Science.gov (United States)

    Brown, Lee E; Palmer, Sheila M; Johnston, Kerrylyn; Holden, Joseph

    2015-05-01

    Vegetation removal with fire can alter the thermal regime of the land surface, leading to significant changes in biogeochemistry (e.g. carbon cycling) and soil hydrology. In the UK, large expanses of carbon-rich upland environments are managed to encourage increased abundance of red grouse (Lagopus lagopus scotica) by rotational burning of shrub vegetation. To date, though, there has not been any consideration of whether prescribed vegetation burning on peatlands modifies the thermal regime of the soil mass in the years after fire. In this study thermal regime was monitored across 12 burned peatland soil plots over an 18-month period, with the aim of (i) quantifying thermal dynamics between burned plots of different ages (from vegetation management. Compared to plots burned 15 + years previously, plots recently burned (vegetation regrows. Our findings that prescribed peatland vegetation burning alters soil thermal regime should provide an impetus for further research to understand the consequences of thermal regime change for carbon processing and release, and hydrological processes, in these peatlands. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Stochastic analysis of uncertain thermal parameters for random thermal regime of frozen soil around a single freezing pipe

    Science.gov (United States)

    Wang, Tao; Zhou, Guoqing; Wang, Jianzhou; Zhou, Lei

    2018-03-01

    The artificial ground freezing method (AGF) is widely used in civil and mining engineering, and the thermal regime of frozen soil around the freezing pipe affects the safety of design and construction. The thermal parameters can be truly random due to heterogeneity of the soil properties, which lead to the randomness of thermal regime of frozen soil around the freezing pipe. The purpose of this paper is to study the one-dimensional (1D) random thermal regime problem on the basis of a stochastic analysis model and the Monte Carlo (MC) method. Considering the uncertain thermal parameters of frozen soil as random variables, stochastic processes and random fields, the corresponding stochastic thermal regime of frozen soil around a single freezing pipe are obtained and analyzed. Taking the variability of each stochastic parameter into account individually, the influences of each stochastic thermal parameter on stochastic thermal regime are investigated. The results show that the mean temperatures of frozen soil around the single freezing pipe with three analogy method are the same while the standard deviations are different. The distributions of standard deviation have a great difference at different radial coordinate location and the larger standard deviations are mainly at the phase change area. The computed data with random variable method and stochastic process method have a great difference from the measured data while the computed data with random field method well agree with the measured data. Each uncertain thermal parameter has a different effect on the standard deviation of frozen soil temperature around the single freezing pipe. These results can provide a theoretical basis for the design and construction of AGF.

  5. Influence of vegetation cover on thermal regime of mountainous catchments

    Czech Academy of Sciences Publication Activity Database

    Tesař, Miroslav; Šír, Miloslav; Lichner, Ľ.; Zelenková, E.

    2006-01-01

    Roč. 61, Suppl. 19 (2006), S311-S314 ISSN 1335-6372 R&D Projects: GA ČR GA205/05/2312 Institutional research plan: CEZ:AV0Z20600510 Keywords : climate * plant transpiration * thermal regime Subject RIV: DA - Hydrology ; Limnology

  6. Temperature structure function in the Bolgiano regime of thermal convection

    Czech Academy of Sciences Publication Activity Database

    Skrbek, Ladislav; Niemela, J. J.; Sreenivasan, K. R.; Donnelly, J.

    2002-01-01

    Roč. 66, č. 3 (2002), 036303/1-036303/6 ISSN 1063-651X Institutional research plan: CEZ:AV0Z1010914 Keywords : thermal convection * temperature fluctuations * Bolgiano regime Subject RIV: BK - Fluid Dynamics Impact factor: 2.397, year: 2002

  7. Advanced Testing Method for Ground Thermal Conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaobing [ORNL; Clemenzi, Rick [Geothermal Design Center Inc.; Liu, Su [University of Tennessee (UT)

    2017-04-01

    A new method is developed that can quickly and more accurately determine the effective ground thermal conductivity (GTC) based on thermal response test (TRT) results. Ground thermal conductivity is an important parameter for sizing ground heat exchangers (GHEXs) used by geothermal heat pump systems. The conventional GTC test method usually requires a TRT for 48 hours with a very stable electric power supply throughout the entire test. In contrast, the new method reduces the required test time by 40%–60% or more, and it can determine GTC even with an unstable or intermittent power supply. Consequently, it can significantly reduce the cost of GTC testing and increase its use, which will enable optimal design of geothermal heat pump systems. Further, this new method provides more information about the thermal properties of the GHEX and the ground than previous techniques. It can verify the installation quality of GHEXs and has the potential, if developed, to characterize the heterogeneous thermal properties of the ground formation surrounding the GHEXs.

  8. The Thermal Regime Around Buried Submarine High-Voltage Cables

    Science.gov (United States)

    Emeana, C. J.; Dix, J.; Henstock, T.; Gernon, T.; Thompson, C.; Pilgrim, J.

    2015-12-01

    The expansion of offshore renewable energy infrastructure and the desire for "trans-continental shelf" power transmission, all require the use of submarine High Voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70oC and are typically buried at depths of 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the thermal properties of near surface shelf sediments are poorly understood and this increases the uncertainty in determining the required cable current ratings, cable reliability and the potential effects on the sedimentary environments. We present temperature measurements from a 2D laboratory experiment, designed to represent a buried, submarine HV cable. We used a large (2.5 m-high) tank, filled with water-saturated ballotini and instrumented with 120 thermocouples, which measured the time-dependent 2D temperature distributions around the heat source. The experiments use a buried heat source to represent a series of realistic cable surface temperatures with the aim for identifying the thermal regimes generated within typical non-cohesive shelf sediments: coarse silt, fine sand and very coarse sand. The steady state heat flow regimes, and normalised and radial temperature distributions were assessed. Our results show that at temperatures up to 60°C above ambient, the thermal regimes are conductive for the coarse silt sediments and convective for the very coarse sand sediments even at 7°C above ambient. However, the heat flow pattern through the fine sand sediment shows a transition from conductive to convective heat flow at a temperature of approximately 20°C above ambient. These findings offer an important new understanding of the thermal regimes associated with submarine HV cables buried in different substrates and has huge impacts on cable ratings as the IEC 60287 standard only considers conductive heat flow as well as other potential near surface impacts.

  9. Thermal Ground State and Nonthermal Probes

    Directory of Open Access Journals (Sweden)

    Thierry Grandou

    2015-01-01

    Full Text Available The Euclidean formulation of SU(2 Yang-Mills thermodynamics admits periodic, (antiself-dual solutions to the fundamental, classical equation of motion which possess one unit of topological charge: (anticalorons. A spatial coarse graining over the central region in a pair of such localised field configurations with trivial holonomy generates an inert adjoint scalar field ϕ, effectively describing the pure quantum part of the thermal ground state in the induced quantum field theory. Here we show for the limit of zero holonomy how (anticalorons associate a temperature independent electric permittivity and magnetic permeability to the thermal ground state of SU2CMB, the Yang-Mills theory conjectured to underlie the fundamental description of thermal photon gases.

  10. Ion thermal confinement in the TFTR enhanced confinement regime

    Energy Technology Data Exchange (ETDEWEB)

    Fonck, R.J.; Howell, R.; Jaehnig, K.; Roquemore, L.; Schilling, G.; Scott, S.; Zarnstorff, M.C.; Bitter, M.; Bush, C.; Goldston, R.

    1988-12-01

    Measurements of the plasma ion temperature and toroidal rotation speed profiles have allowed the study of ion thermal transport in the TFTR hot ion enhanced confinement regime. Central ion temperatures up to 30 keV and rotation speeds up to 8 x 10/sup 5/ m/sec have been confirmed with new diagnostic measurements, and the ion thermal diffusivity is found to be non-neoclassical and comparable to the anomalous electron thermal diffusivity. The dominant effects of strong rotation are the down-shifting of the neutral beam energies in the plasma frame, which results in reduced ion and electron heating on axis, and the presence of off-axis ion heating from viscous damping of the plasma rotation. 14 refs., 3 figs.

  11. Discriminating glacier thermal and dynamic regimes in the sedimentary record

    Science.gov (United States)

    Hambrey, Michael J.; Glasser, Neil F.

    2012-04-01

    This paper provides a description and evaluation of the sedimentary facies and environments associated with a range of glacier thermal and dynamic regimes, with additional consideration given to the tectonic context. New and previously published data are evaluated together, and are presented from modern terrestrial and marine glacial sedimentary environments in order to identify a set of criteria that can be used to discriminate between different glacier thermal regimes and dynamic styles in the sedimentary record. Sedimentological data are presented from a total of 28 glaciers in 11 geographical areas that represent a wide range of contemporary thermal, dynamic and topographic regimes. In the context of "landsystems", representatives from terrestrial environments include temperate glaciers in the European Alps, Patagonia, New Zealand, the Cordillera Blanca (Peru), cold glaciers in the Dry Valleys of Antarctica and the Antarctic Peninsula region, and polythermal valley glaciers in Svalbard, northern Sweden, the Yukon and the Khumbu Himal (Nepal). The glaciomarine environment is illustrated by data from cold and polythermal glacier margins on the East Antarctic continental shelf, and from a polythermal tidewater glacier in Svalbard, along with general observations from temperate glaciers in Alaska. These data show that temperate glacial systems, particularly in high-relief areas, are dominated by rockfall and avalanche processes, although sediments are largely reworked by glaciofluvial processes. Debris in polythermal glaciers is both thermally and topographically influenced. In areas of moderate relief, debris is mainly of basal glacial origin, and the resulting facies association is dominated by diamicton. In high-relief areas such as the Himalaya, the debris load in polythermal glaciers is dominated by rockfall and avalanche inputs, resulting in extensive accumulations of sandy boulder-gravel. Cold glaciers are dominated by basal debris-entrainment, but sediments

  12. Quasiparticle explanation of ``weak thermalization'' regime under quench in a non-integrable quantum spin chain

    Science.gov (United States)

    Lin, Cheng-Ju; Motrunich, Olexei

    Eigenstate Thermalization Hypothesis provides one picture of thermalization in a quantum system by looking at individual eigenstates. However, it is also important to consider how local observables reach equilibrium values dynamically. Quench protocol is one of the settings to study such questions. A recent numerical study [Banuls, Cirac, and Hastings, Phys. Rev. Lett. 106, 050405 (2011)] of a nonintegrable quantum Ising model with longitudinal field under such quench setting found different behaviors under different initial quantum states. One particular case termed ``weak thermalization'' regime showed apparently persistent oscillations of some observables. Here we provide an explanation of such oscillations. We use perturbation theory near the ground state of the model, and identify the oscillation frequency as the quasiparticle mass. With this quasiparticle picture, we can then address the long-time behavior of the oscillations.

  13. Historical thermal regimes define limits to coral acclimatization.

    Science.gov (United States)

    Howells, Emily J; Berkelmans, Ray; van Oppen, Madeleine J H; Willis, Bette L; Bay, Line K

    2013-05-01

    Knowledge of the degree to which corals undergo physiological acclimatization or genetic adaptation in response to changes in their thermal environment is crucial to the success of coral reef conservation strategies. The potential of corals to acclimatize to temperatures exceeding historical thermal regimes was investigated by reciprocal transplantation of Acropora millepora colonies between the warm central and cool southern regions of the Great Barrier Reef (GBR) for a duration of 14 months. Colony fragments retained at native sites remained healthy, whereas transplanted fragments, although healthy over initial months when temperatures remained within native thermal regimes, subsequently bleached and suffered mortality during seasonal temperature extremes. Corals hosting Symbiodinium D transplanted to the southern GBR bleached in winter and the majority suffered whole (40%; n=20 colonies) or partial (50%) mortality at temperatures 1.1 degrees C below their 15-year native minimum. In contrast, corals hosting Symbiodinium C2 transplanted to the central GBR bleached in summer and suffered whole (50%; n=10 colonies) or partial (42%) mortality at temperatures 2.5 degrees C above their 15-year native maximum. During summer bleaching, the dominant Symbiodinium type changed from C2 to D within corals transplanted to the central GBR. Corals transplanted to the cooler, southern GBR grew 74-80% slower than corals at their native site, and only 50% of surviving colonies reproduced, at least partially because of cold water bleaching of transplants. Despite the absence of any visual signs of stress, corals transplanted to the warmer, central GBR grew 52-59% more slowly than corals at their native site before the summer bleaching (i.e., from autumn to spring). Allocation of energy to initial acclimatization or reproduction may explain this pattern, as the majority (65%) of transplants reproduced one month earlier than portions of the same colonies retained at the southern

  14. Variations and controls on crustal thermal regimes in Southeastern Australia

    Science.gov (United States)

    Mather, Ben; McLaren, Sandra; Taylor, David; Roy, Sukanta; Moresi, Louis

    2018-01-01

    The surface heat flow field in Australia has for many years been poorly constrained compared to continental regions elsewhere. 182 recent heat flow determinations and 66 new heat production measurements for Southeastern Australia significantly increase our understanding of local and regional lithospheric thermal regimes and allow for detailed thermal modelling. The new data give a mean surface heat flow for Victoria of 71 ± 15 mW m- 2 which fits within the 61-77 mW m- 2 range reported for Phanerozoic-aged crust globally. These data reveal three new thermally and compositionally distinct heat flow sub-provinces within the previously defined Eastern Heat Flow Province: the Delamerian heat flow sub-province (average surface heat flow 60 ± 9 mW m- 2); the Lachlan heat flow sub-province (average surface heat flow 74 ± 13 mW m- 2); and the Newer Volcanics heat flow sub-province (average surface heat flow 72 ± 16 mW m- 2) which includes extreme values that locally exceed 100 mW m- 2. Inversions of reduced heat flow and crustal differentiation find that the Delamerian sub-province has experienced significant crustal reworking compared to the Lachlan and Newer Volcanics sub-provinces. The latter has experienced volcanism within the last 8 Ma and the degree of variability observed in surface heat flow points (up to 8 mW m- 2 per kilometre laterally) cannot be replicated with steady-state thermal models through this sub-province. In the absence of a strong palaeoclimate signal, aquifer disturbances, or highly enriched granites, we suggest that this high variability arises from localised transient perturbations to the upper crust associated with recent intraplate volcanism. This is supported by a strong spatial correlation of high surface heat flow and known eruption points within the Newer Volcanics heat flow sub-province.

  15. Quasiparticle explanation of the weak-thermalization regime under quench in a nonintegrable quantum spin chain

    Science.gov (United States)

    Lin, Cheng-Ju; Motrunich, Olexei I.

    2017-02-01

    The eigenstate thermalization hypothesis provides one picture of thermalization in a quantum system by looking at individual eigenstates. However, it is also important to consider how local observables reach equilibrium values dynamically. Quench protocol is one of the settings to study such questions. A recent numerical study [Bañuls, Cirac, and Hastings, Phys. Rev. Lett. 106, 050405 (2007), 10.1103/PhysRevLett.106.050405] of a nonintegrable quantum Ising model with longitudinal field under such a quench setting found different behaviors for different initial quantum states. One particular case called the "weak-thermalization" regime showed apparently persistent oscillations of some observables. Here we provide an explanation of such oscillations. We note that the corresponding initial state has low energy density relative to the ground state of the model. We then use perturbation theory near the ground state and identify the oscillation frequency as essentially a quasiparticle gap. With this quasiparticle picture, we can then address the long-time behavior of the oscillations. Upon making additional approximations which intuitively should only make thermalization weaker, we argue that the oscillations nevertheless decay in the long-time limit. As part of our arguments, we also consider a quench from a BEC to a hard-core boson model in one dimension. We find that the expectation value of a single-boson creation operator oscillates but decays exponentially in time, while a pair-boson creation operator has oscillations with a t-3 /2 decay in time. We also study dependence of the decay time on the density of bosons in the low-density regime and use this to estimate decay time for oscillations in the original spin model.

  16. The thermal regime around buried submarine high-voltage cables

    Science.gov (United States)

    Emeana, C. J.; Hughes, T. J.; Dix, J. K.; Gernon, T. M.; Henstock, T. J.; Thompson, C. E. L.; Pilgrim, J. A.

    2016-08-01

    The expansion of offshore renewable energy infrastructure and the need for trans-continental shelf power transmission require the use of submarine high-voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70 °C and are typically buried 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the heat flow pattern and potential effects on the sedimentary environments around such anomalously high heat sources in the near-surface sediments are poorly understood. We present temperature measurements from a 2-D laboratory experiment representing a buried submarine HV cable, and identify the thermal regimes generated within typical unconsolidated shelf sediments—coarse silt, fine sand and very coarse sand. We used a large (2 × 2.5 m2) tank filled with water-saturated spherical glass beads (ballotini) and instrumented with a buried heat source and 120 thermocouples to measure the time-dependent 2-D temperature distributions. The observed and corresponding Finite Element Method simulations of the steady state heat flow regimes and normalized radial temperature distributions were assessed. Our results show that the heat transfer and thus temperature fields generated from submarine HV cables buried within a range of sediments are highly variable. Coarse silts are shown to be purely conductive, producing temperature increases of >10 °C up to 40 cm from the source of 60 °C above ambient; fine sands demonstrate a transition from conductive to convective heat transfer between cf. 20 and 36 °C above ambient, with >10 °C heat increases occurring over a metre from the source of 55 °C above ambient; and very coarse sands exhibit dominantly convective heat transfer even at very low (cf. 7 °C) operating temperatures and reaching temperatures of up to 18 °C above ambient at a metre from the source at surface temperatures of only 18 °C. These findings are important for the surrounding near

  17. THERMAL REGIME OF MASSIVE CONCRETE DAMS WITH AIR CAVITIES IN THE SEVERE CLIMATE

    Directory of Open Access Journals (Sweden)

    Aniskin Nikolay Alekseevich

    2012-12-01

    The thermal regime of the concrete dam with an air cavity can be adjustable by simple structural elements, including a heat-insulating wall and artificial heating of cavities. The required intensity and duration of heating are to be identified. Final conclusions about the most favorable thermal regime pattern will be made upon completion of fundamental calculations of the thermal stress state of the dam to be performed in the next phase of the research.

  18. Changes in the ground water regime in the Straz block due to uranium mining

    International Nuclear Information System (INIS)

    Fiedler, J.

    1993-01-01

    The geology and hydrogeology are characterized of the Cenomanian and Turonian collectors in the uranium deposit region near the town of Straz pod Ralskem. The ground water regime was changed by pumping off 760 m 3 and pressing in 470 m 3 of solutions (out of this, 450 and 150 m 3 of water, respectively). This brought about an overall change in the hydraulic situation. The uranium mining also led to significant changes in the chemical composition of ground water in the Cenomanian collector; the Turonian collector has also been affected to some extent. Anomalously high concentrations of contaminants in the investigated region brought about by changes in the ground water regime, pose a major risk. The basic principles of a system approach to rectifying this situation are explained. (J.B.). 1 tab., 7 figs., 7 refs

  19. Parametric study of thermal and thermodynamic properties on pyrolysis of biomass in thermally thick regime

    International Nuclear Information System (INIS)

    Babu, B.V.; Chaurasia, A.S.

    2004-01-01

    In the present study, a simultaneous chemical kinetics and heat transfer model is used to predict the effects of the most important thermal and thermodynamic properties (thermal conductivity, heat transfer coefficient, emissivity and heat of reaction number) of the feedstock on the convective-radiant pyrolysis of biomass fuels. A finite difference pure implicit scheme utilizing the tri-diagonal matrix algorithm is employed for solving the heat transfer model equation. The Runge-Kutta fourth-order method is used for the chemical kinetics model equations. Simulations are performed considering cylindrical pellets of equivalent radius ranging from 0.003 to 0.011 m and temperatures ranging from 303 to 900 K. For conversion in the thermally thick regime (intra-particle heat transfer control), it is found that variations in the properties mainly affect the activity of the primary reactions. Sensitivity analysis is conducted to find the most dominant properties affecting the pyrolysis and found that the highest sensitivity is associated with the emissivity and thermal conductivity of the biomass. Applications of these findings in reactor design and operation are discussed. The results obtained using the improved models are in excellent agreement with the experimental data, much better than the agreement with the earlier models reported in the literature

  20. Ion thermal conductivity and ion distribution function in the banana regime

    International Nuclear Information System (INIS)

    Taguchi, Masayoshi

    1988-01-01

    A method for calculating the ion thermal conductivity and the ion distribution function in the banana regime is formulated for an axisymmetric toroidal plasma of arbitrary aspect ratio. A simple expression for this conductivity is also derived. (author)

  1. Long-lasting floods buffer the thermal regime of the Pampas

    Science.gov (United States)

    Houspanossian, Javier; Kuppel, Sylvain; Nosetto, Marcelo; Di Bella, Carlos; Oricchio, Patricio; Barrucand, Mariana; Rusticucci, Matilde; Jobbágy, Esteban

    2018-01-01

    The presence of large water masses influences the thermal regime of nearby land shaping the local climate of coastal areas by the ocean or large continental lakes. Large surface water bodies have an ephemeral nature in the vast sedimentary plains of the Pampas (Argentina) where non-flooded periods alternate with flooding cycles covering up to one third of the landscape for several months. Based on temperature records from 17 sites located 1 to 700 km away from the Atlantic coast and MODIS land surface temperature data, we explore the effects of floods on diurnal and seasonal thermal ranges as well as temperature extremes. In non-flooded periods, there is a linear increase of mean diurnal thermal range (DTR) from the coast towards the interior of the region (DTR increasing from 10 to 16 K, 0.79 K/100 km, r 2 = 0.81). This relationship weakens during flood episodes when the DTR of flood-prone inland locations shows a decline of 2 to 4 K, depending on surface water coverage in the surrounding area. DTR even approaches typical coastal values 500 km away from the ocean in the most flooded location that we studied during the three flooding cycles recorded in the study period. Frosts-free periods, a key driver of the phenology of both natural and cultivated ecosystems, are extended by up to 55 days during floods, most likely as a result of enhanced ground heat storage across the landscape ( 2.7 fold change in day-night heat transfer) combined with other effects on the surface energy balance such as greater night evaporation rates. The reduced thermal range and longer frost-free periods affect plant growth development and may offer an opportunity for longer crop growing periods, which may not only contribute to partially compensating for regional production losses caused by floods, but also open avenues for flood mitigation through higher plant evapotranspirative water losses.

  2. Fluid temperatures: Modeling the thermal regime of a river network

    Science.gov (United States)

    Rhonda Mazza; Ashley Steel

    2017-01-01

    Water temperature drives the complex food web of a river network. Aquatic organisms hatch, feed, and reproduce in thermal niches within the tributaries and mainstem that comprise the river network. Changes in water temperature can synchronize or asynchronize the timing of their life stages throughout the year. The water temperature fluctuates over time and place,...

  3. Logarithmic temperature profiles in the ultimate regime of thermal convection

    NARCIS (Netherlands)

    Grossmann, S.; Lohse, Detlef

    2012-01-01

    We report on the theory of logarithmic temperature profiles in very strongly developed thermal convection in the geometry of a Rayleigh-Bénard cell with aspect ratio (defined by cell width divided by cell height) Γ = 1, and discuss the degree of agreement with the recently measured profiles in the

  4. The DOE Thermal Regimes Drilling Program through 1987

    Energy Technology Data Exchange (ETDEWEB)

    1988-07-01

    In response to strong endorsement from the scientific community, in the form of a report by the Continental Scientific Drilling Committee of the National Academy of Sciences (CSDC, 1984), the Office of Basic Energy Sciences of the DOE undertook a program of investigations of young magmatic intrusions and their associated thermal systems. To date, the effort has encompassed the first phases of a program to investigate the roots of active hydrothermal systems and has also investigated the thermal, chemical, and mechanical behavior of geologically recent (less than 600 years) magmatic extrusions. Shallow to intermediate-depth holes have been drilled and cored into hydrothermal systems in the silicic Valles and Long Valley calderas and at the crustal spreading center of the Salton Trough. These projects are briefly summarized here and are covered in greater detail in the accompanying appendices.

  5. Thermal regimes of Rocky Mountain lakes warm with climate change

    Science.gov (United States)

    Roberts, James J.; Fausch, Kurt D.; Schmidt, Travis S.; Walters, David M.

    2017-01-01

    Anthropogenic climate change is causing a wide range of stresses in aquatic ecosystems, primarily through warming thermal conditions. Lakes, in response to these changes, are experiencing increases in both summer temperatures and ice-free days. We used continuous records of lake surface temperature and air temperature to create statistical models of daily mean lake surface temperature to assess thermal changes in mountain lakes. These models were combined with downscaled climate projections to predict future thermal conditions for 27 high-elevation lakes in the southern Rocky Mountains. The models predict a 0.25°C·decade-1increase in mean annual lake surface temperature through the 2080s, which is greater than warming rates of streams in this region. Most striking is that on average, ice-free days are predicted to increase by 5.9 days ·decade-1, and summer mean lake surface temperature is predicted to increase by 0.47°C·decade-1. Both could profoundly alter the length of the growing season and potentially change the structure and function of mountain lake ecosystems. These results highlight the changes expected of mountain lakes and stress the importance of incorporating climate-related adaptive strategies in the development of resource management plans.

  6. Thermal regimes of Rocky Mountain lakes warm with climate change.

    Directory of Open Access Journals (Sweden)

    James J Roberts

    Full Text Available Anthropogenic climate change is causing a wide range of stresses in aquatic ecosystems, primarily through warming thermal conditions. Lakes, in response to these changes, are experiencing increases in both summer temperatures and ice-free days. We used continuous records of lake surface temperature and air temperature to create statistical models of daily mean lake surface temperature to assess thermal changes in mountain lakes. These models were combined with downscaled climate projections to predict future thermal conditions for 27 high-elevation lakes in the southern Rocky Mountains. The models predict a 0.25°C·decade-1 increase in mean annual lake surface temperature through the 2080s, which is greater than warming rates of streams in this region. Most striking is that on average, ice-free days are predicted to increase by 5.9 days ·decade-1, and summer mean lake surface temperature is predicted to increase by 0.47°C·decade-1. Both could profoundly alter the length of the growing season and potentially change the structure and function of mountain lake ecosystems. These results highlight the changes expected of mountain lakes and stress the importance of incorporating climate-related adaptive strategies in the development of resource management plans.

  7. Thermal regimes of Rocky Mountain lakes warm with climate change.

    Science.gov (United States)

    Roberts, James J; Fausch, Kurt D; Schmidt, Travis S; Walters, David M

    2017-01-01

    Anthropogenic climate change is causing a wide range of stresses in aquatic ecosystems, primarily through warming thermal conditions. Lakes, in response to these changes, are experiencing increases in both summer temperatures and ice-free days. We used continuous records of lake surface temperature and air temperature to create statistical models of daily mean lake surface temperature to assess thermal changes in mountain lakes. These models were combined with downscaled climate projections to predict future thermal conditions for 27 high-elevation lakes in the southern Rocky Mountains. The models predict a 0.25°C·decade-1 increase in mean annual lake surface temperature through the 2080s, which is greater than warming rates of streams in this region. Most striking is that on average, ice-free days are predicted to increase by 5.9 days ·decade-1, and summer mean lake surface temperature is predicted to increase by 0.47°C·decade-1. Both could profoundly alter the length of the growing season and potentially change the structure and function of mountain lake ecosystems. These results highlight the changes expected of mountain lakes and stress the importance of incorporating climate-related adaptive strategies in the development of resource management plans.

  8. Effluent treatment options for nuclear thermal propulsion system ground tests

    International Nuclear Information System (INIS)

    Shipers, L.R.; Brockmann, J.E.

    1992-01-01

    A variety of approaches for handling effluent from nuclear thermal propulsion system ground tests in an environmentally acceptable manner are discussed. The functional requirements of effluent treatment are defined and concept options are presented within the framework of these requirements. System concepts differ primarily in the choice of fission-product retention and waste handling concepts. The concept options considered range from closed cycle (venting the exhaust to a closed volume or recirculating the hydrogen in a closed loop) to open cycle (real time processing and venting of the effluent). This paper reviews the strengths and weaknesses of different methods to handle effluent from nuclear thermal propulsion system ground tests

  9. A Ground-Nesting Galliform's Response to Thermal Heterogeneity: Implications for Ground-Dwelling Birds.

    Directory of Open Access Journals (Sweden)

    J Matthew Carroll

    Full Text Available The habitat selection choices that individuals make in response to thermal environments influence both survival and reproduction. Importantly, the way that organisms behaviorally respond to thermal environments depends on the availability and juxtaposition of sites affording tolerable or preferred microclimates. Although, ground nesting birds are especially susceptible to heat extremes across many reproductive stages (i.e., breeding, nesting, brood rearing, the mechanistic drivers of nest site selection for these species are not well established from a thermal perspective. Our goal was to assess nest site selection relative to the configuration of the thermal landscape by quantifying thermal environments available to a ground-nesting bird species inhabiting a climatically stressful environment. Using northern bobwhite (Colinus virginanus as a model species, we measured black bulb temperature (Tbb and vegetation parameters at 87 nests, 87 paired sites and 205 random landscape sites in Western Oklahoma during spring and summer 2013 and 2014. We found that thermal space within the study area exhibited differences in Tbb of up to 40°C during peak diurnal heating, resulting in a diverse thermal landscape available to ground-nesting birds. Within this thermally heterogeneous landscape, nest sites moderated Tbb by more than 12°C compared to random landscape sites. Furthermore, successful nests remained on average 6°C cooler than unsuccessful nests on days experiencing ambient temperatures ≥ 39°C. Models of future Tbb associated with 2080 climate change projections indicate that nesting bobwhites will face substantially greater Tbb throughout the landscape for longer durations, placing an even greater importance on thermal choices for nest sites in the future. These results highlight the capacity of landscape features to act as moderators of thermal extremes and demonstrate how thermal complexity at organism-specific scales can dictate habitat

  10. Cold exposure and associated metabolic changes in adult tropical beetles exposed to fluctuating thermal regimes

    Czech Academy of Sciences Publication Activity Database

    Lalouette, L.; Košťál, Vladimír; Colinet, H.; Gagneul, D.; Renault, D.

    2007-01-01

    Roč. 274, č. 7, (2007), s. 1759-1767 ISSN 1742-464X Grant - others: Biodiversity Research Centre of the Université Catholique de Louvain(BE) BRC 111 Institutional research plan: CEZ:AV0Z50070508 Keywords : amino acid * fluctuating thermal regime * insect Subject RIV: ED - Physiology Impact factor: 3.396, year: 2007

  11. Apparent relationship between thermal regime in Antarctic waters and Indian summer monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Menon, H.B.; RameshBabu, V.; Sastry, J.S.

    ) charts for the Indian Ocean sector of the Southern Ocean during 2 contrasting years (1977 and 1979) of summer monsoon over India. The results suggest an apparent relationship between the thermal regimes in the Antarctic waters of the Indian Ocean sector...

  12. Predicting thermal regimes of stream networks across the Chesapeake Bay Watershed: Natural and anthropogenic influences

    Science.gov (United States)

    Thermal regimes are a critical factor in models predicting joint effects of watershed management activities and climate change on fish habitat suitability. We have compiled a database of lotic temperature time series across the Chesapeake Bay Watershed (725 station-year combinat...

  13. Incorporating Retention Time to Refine Models Predicting Thermal Regimes of Stream Networks Across New England

    Science.gov (United States)

    Thermal regimes are a critical factor in models predicting effects of watershed management activities on fish habitat suitability. We have assembled a database of lotic temperature time series across New England (> 7000 station-year combinations) from state and Federal data s...

  14. Predicting Thermal Regimes of Stream Networks Across New England: Natural and Anthropogenic Influences

    Science.gov (United States)

    Thermal regime is a critical factor in models predicting joint effects of watershed management activities and climate change on habitat suitability for fish. We used a database of lotic temperature time series across New England (> 7000 station-year combinations) from state a...

  15. Network-based Prediction of Lotic Thermal Regimes Across New England

    Science.gov (United States)

    Thermal regimes are a critical factor in models predicting effects of watershed management activities on fish habitat suitability. We have assembled a database of lotic temperature time series across New England (> 7000 station-year combinations) from state and Federal data sour...

  16. Thermal noise in double injection diodes operating in the insulator regime

    NARCIS (Netherlands)

    Zijlstra, R.J.J.; Gisolf, A.

    Thermal noise calculations, based on the Langevin procedure, are given for a double injection diode operating in the insulator regime. The frequency range is restricted to frequencies smaller than the reciprocal free carrier transit times. It turns out that at high frequencies the spectral density

  17. Factors Influencing the Thermal Efficiency of Horizontal Ground Heat Exchangers

    Directory of Open Access Journals (Sweden)

    Eloisa Di Sipio

    2017-11-01

    Full Text Available The performance of very shallow geothermal systems (VSGs, interesting the first 2 m of depth from ground level, is strongly correlated to the kind of sediment locally available. These systems are attractive due to their low installation costs, less legal constraints, easy maintenance and possibility for technical improvements. The Improving Thermal Efficiency of horizontal ground heat exchangers Project (ITER aims to understand how to enhance the heat transfer of the sediments surrounding the pipes and to depict the VSGs behavior in extreme thermal situations. In this regard, five helices were installed horizontally surrounded by five different backfilling materials under the same climatic conditions and tested under different operation modes. The field test monitoring concerned: (a monthly measurement of thermal conductivity and moisture content on surface; (b continuous recording of air and ground temperature (inside and outside each helix; (c continuous climatological and ground volumetric water content (VWC data acquisition. The interactions between soils, VSGs, environment and climate are presented here, focusing on the differences and similarities between the behavior of the helix and surrounding material, especially when the heat pump is running in heating mode for a very long time, forcing the ground temperature to drop below 0 °C.

  18. Analyzing the thermal regime of power supply units in portable betatrons by using infrared thermography

    Directory of Open Access Journals (Sweden)

    Simonova O.S.

    2017-01-01

    Full Text Available Potentials of infrared thermography in analyzing a thermal regime of the 7.5 MeV betatron power supply are discussed. Both the heating rate and thermal inertia of particular electronic components have been evaluated by processing pixel-based temperature histories. The data treatment has been performed by using the original ThermoFit Pro software to illustrate that some advanced processing algorithms, such as the Fourier transform and principle component analysis, are valuable in identifying thermal dynamics of particular power supply parts.

  19. Numerical Modelling of Tailings Dam Thermal-Seepage Regime Considering Phase Transitions

    Directory of Open Access Journals (Sweden)

    Aniskin Nikolay Alekseevich

    2017-01-01

    Full Text Available Statement of the Problem. The article describes the problem of combined thermal-seepage regime for earth dams and those operated in the permafrost conditions. This problem can be solved using the finite elements method based on the local variational formulation. Results. A thermal-seepage regime numerical model has been developed for the “dam-foundation” system in terms of the tailings dam. The effect of heat-and-mass transfer and liquid phase transition in soil interstices on the dam state is estimated. The study with subsequent consideration of these factors has been undertaken. Conclusions. The results of studying the temperature-filtration conditions of the structure based on the factors of heat-and-mass transfer and liquid phase transition have shown that the calculation results comply with the field data. Ignoring these factors or one of them distorts the real situation of the dam thermal-seepage conditions.

  20. Thermal Performance Analyses of Multiborehole Ground Heat Exchangers

    Directory of Open Access Journals (Sweden)

    Wanjing Luo

    2017-01-01

    Full Text Available Geothermal energy known as a clean, renewable energy resource is widely available and reliable. Ground heat exchangers (GHEs can assist the development of geothermal energy by reducing the capital cost and greenhouse gas emission. In this paper, a novel semianalytical method was developed to study the thermal performance of multiborehole ground heat exchangers (GHEs with arbitrary configurations. By assuming a uniform inlet fluid temperature (UIFT, instead of uniform heat flux (UHF, the effects of thermal interference and the thermal performance difference between different boreholes can be examined. Simulation results indicate that the monthly average outlet fluid temperatures of GHEs will increase gradually while the annual cooling load of the GHEs is greater than the annual heating load. Besides, two mechanisms, the thermal dissipation and the heat storage effect, will determine the heat transfer underground, which can be further divided into four stages. Moreover, some boreholes will be malfunctioned; that is, boreholes can absorb heat from ground when the GHEs are under the cooling mode. However, as indicated by further investigations, this malfunction can be avoided by increasing borehole spacing.

  1. Influence of Diffuse and Discrete Groundwater Discharge on River Thermal Regimes in Present and Future Climates

    Science.gov (United States)

    Kurylyk, B.; MacQuarrie, K. T. B.

    2015-12-01

    Groundwater discharge alters stream and river thermal regimes due to the thermal inertia of the subsurface, but the exact nature of its influence depends on the discharge conditions. Diffuse groundwater discharge attenuates daily, weekly, and seasonal changes in surface water temperature. On the other hand, discrete groundwater discharge (e.g., a spring) creates in-stream thermal anomalies that provide temporary refuge for cold-water fish and other aquatic species. Thus, diffusive groundwater input reduces the temporal variability of surface water temperature, while discrete groundwater input enhances its spatial variability. In the present climate, thermal effects of groundwater discharge can be empirically studied by comparing thermal regimes of groundwater-dominated streams to those of runoff-dominated streams. However, there are still many challenges associated with attempting to quantify the thermal influence of groundwater discharge. These difficulties arise in part because the heat flux from groundwater upwelling is induced by a mass flux, and thus it cannot be directly compared to purely sensible heat fluxes. Also, shallow subsurface flow exhibits complex thermal signatures that are not well represented with mean annual air temperature data. Examining the thermal influence of groundwater discharge becomes even more complex when potential effects of climate change are considered. Results from previous studies utilizing empirical transfer models, analytical solutions, and numerical models of groundwater temperature dynamics have demonstrated that the nature of groundwater warming depends on the soil properties, groundwater recharge rate, and aquifer configuration. This talk will highlight challenges associated with quantifying the thermal influence of groundwater discharge and provide recommendations for future research opportunities in this field, including the potential to engineer thermal diversity in rivers via manipulation of groundwater flow paths.

  2. CRYogenic Orbital TEstbed Ground Test Article Thermal Analysis

    Science.gov (United States)

    Piryk, David; Schallhorn, Paul; Walls, Laurie; Stopnitzky, Benny; Rhys, Noah; Wollen, Mark

    2012-01-01

    The purpose of this study was to anchor thermal and fluid system models to CRYOTE ground test data. The CRYOTE ground test artide was jointly developed by Innovative Engineering Solutions, United Launch Alliance and NASA KSC. The test article was constructed out of a titanium alloy tank, Sapphire 77 composite skin (similar to G10), an external secondary payload adapter ring, thermal vent system, multi layer insulation and various data acquisition instrumentation. In efforts to understand heat loads throughout this system, the GTA (filled with liquid nitrogen for safety purposes) was subjected to a series of tests in a vacuum chamber at Marshall Space Flight Center. By anchoring analytical models against test data, higher fidelity thermal environment predictions can be made for future flight articles which would eventually demonstrate critical cryogenic fluid management technologies such as system chilldown, transfer, pressure control and long term storage. Significant factors that influenced heat loads included radiative environments, multi-layer insulation performance, tank fill levels and pressures and even contact conductance coefficients. This report demonstrates how analytical thermal/fluid networks were established and includes supporting rationale for specific thermal responses.

  3. Influence of Local Zones of Intensive Heat Transfer on Thermal Regime of Heat Supply Objects

    Directory of Open Access Journals (Sweden)

    Maksimov Vyacheslav I.

    2015-01-01

    Full Text Available The results of mathematical simulation of conjugate heat transfer for heat supply object are represented. The turbulent regime of air motion in a closed cavity with the enclosing walls from reinforced concrete and glass is examined. On the outer boundary, which includes window aperture, the conditions of convective-radiation heat exchange with environment are realized. Is solved the system of the dimensionless equations within the framework of thermal conductivity model for the solid walls and Navier-Stokes for the gas. The influence of the local zones of intensive heat transfer on the thermal regime of the heat supply objects is established. Are determined the values of the dimensionless heat exchange coefficient on division border “air - wall”. The analysis of the values of mean temperatures of the solution region is carried out.

  4. Thermal regime of three low elevation scree slopes in central Europe

    Czech Academy of Sciences Publication Activity Database

    Zacharda, Miloslav; Gude, M.; Růžička, Vlastimil

    2007-01-01

    Roč. 18, č. 3 (2007), s. 301-308 ISSN 1045-6740 R&D Projects: GA ČR GA205/06/1236; GA AV ČR IAA6007401 Institutional research plan: CEZ:AV0Z50070508; CEZ:AV0Z60870520 Keywords : low elevation scree slope * thermal regime Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.633, year: 2007

  5. Seasonal thermal regime and climatic trends in lakes of the Tibetan highlands

    Science.gov (United States)

    Kirillin, Georgiy; Wen, Lijuan; Shatwell, Tom

    2017-04-01

    The hydrology of the lake-rich Tibetan Plateau is important for the global climate, yet little is known about the thermal regime of Tibetan lakes due to scant data. We (i) investigated the characteristic seasonal temperature patterns and recent trends in the thermal and stratification regimes of lakes on the Tibetan Plateau and (ii) tested the performance of the one-dimensional lake parameterization scheme FLake for the Tibetan lake system. For this purpose, we combined 3 years of in situ lake temperature measurements, several decades of satellite observations, and the global reanalysis data. We chose the two largest freshwater Tibetan lakes, Ngoring and Gyaring, as study sites. The lake model FLake faithfully reproduced the specific features of the high-altitude lakes and was subsequently applied to reconstruct the vertically resolved heat transport in both lakes during the last 4 decades. The model suggested that Ngoring and Gyaring were ice-covered for about 6 months and stratified in summer for about 4 months per year with a short spring overturn and a longer autumn overturn. In summer the surface mixed boundary layer extended to 6-8 m of depth and was about 20 % shallower in the more turbid Gyaring. The thermal regime of the transparent Ngoring responded more strongly to atmospheric forcing than Gyaring, where the higher turbidity damped the response. According to the reanalysis data, air temperatures and humidity have increased, whereas solar radiation has decreased, since the 1970s. Surprisingly, the modeled mean lake temperatures did not change, nor did the phenology of the ice cover or stratification. Lake surface temperatures in summer increased only marginally. The reason is that the increase in air temperature was offset by the decrease in radiation, probably due to increasing humidity. This study demonstrates that air temperature trends are not directly coupled to lake temperatures and underscores the importance of shortwave radiation for the thermal

  6. Seabed Morphology and Sedimentary Regimes defining Fishing Grounds along the Eastern Brazilian Shelf

    Directory of Open Access Journals (Sweden)

    Silvia N. Bourguignon

    2018-03-01

    Full Text Available Shelf morphology and sedimentary regimes are influenced by processes operating at different temporal and spatial scales and are important records of sea level changes and sediment supply and/or carbonate production. The northern continental shelf of Espírito Santo (Brazil contains evidence of different sedimentary regimes that distribute diverse and complex marine habitats. Herein, seabed morphology, acoustic images of the seafloor (side scan sonar and sub-bottom profiler, and sediment samples were used to investigate the influence of sedimentary regimes on physical marine habitat distribution. Seabed mapping is also integrated with available data on fisheries to understand the influence of shelf morphology and sedimentology in the usage of distinct fishing gears. The results indicate five morpho-sedimentary facies: terrigenous mud, terrigenous sand, rhodolith beds, carbonate gravel with rhodoliths, and hardground. Through an integrated analysis of the geomorphology and sedimentary distribution, two morpho-sedimentary domains were identified: a sediment-fed shelf adjacent to the Doce River associated with a major mud depocenter and a delta front morphology characterized by gentle slopes and low terrain ruggedness, and a sediment-starved shelf dominated by carbonate sedimentation showing an irregular morphology associated with higher slopes and terrain ruggedness. These contrasting morpho-sedimentary domains are a result of sedimentary responses to sea level fluctuation during Late Quaternary, specially, during the deglaciation processes after the Last Glacial Maximum. The morphological and sedimentary contrasts along the area define the physical habitat distribution. The sediment supply regime area is associated with a terrigenous fine/muddy sedimentation bed, which control the local morphology and favors coastal and delta front progradation. This physical habitat is a well-known shrimp-fishing ground where intense trawling takes place, as well

  7. Seasonal Evolution of Thermal Conductivity of Snow and its Impact on Surface Temperature Regimes

    Science.gov (United States)

    Alexeev, V. A.; Kholodov, A. L.

    2017-12-01

    Snow acts as an insulating blanket for permafrost in the winter. Thermal conductivity properties of snowpack in the winter will greatly impact the temperature regimes of the underlaying permafrost. Fourier analysis and other techniques are applied to data obtained from a set of observational sites in Fairbanks, AK with temperature and moisture measured within the snowpack throughout the entire winter in order to estimate thermal conductivity of snow and fluxes through the snow. These data are analyzed in order to understand the variations of soil temperature as a function of snow properties and weather conditions. Thermal diffusion coefficients, snow depth and density data are compared with other available sources. Results obtained will be used for further development of a snow-permafrost model.

  8. Thermal Effects on the Single-Mode Regime of Distributed Modal Filtering Rod Fiber

    DEFF Research Database (Denmark)

    Coscelli, Enrico; Poli, Federica; Alkeskjold, Thomas Tanggaard

    2012-01-01

    Power scaling of fiber laser systems requires the development of innovative active fibers, capable of providing high pump absorption, ultralarge effective area, high-order mode suppression, and resilience to thermal effects. Thermally induced refractive index change has been recently appointed...... rod-type photonic crystal fiber, which exploits resonant coupling with high-index elements to suppress high-order modes, are thoroughly investigated. A computationally efficient model has been developed to calculate the refractive index change due to the thermo-optical effect, and it has been...... integrated into a full-vector modal solver based on the finite-element method to obtain the guided modes, considering different heating conditions. Results have shown that the single-mode regime of the distributed modal filtering fiber is less sensitive to thermal effects with respect to index-guiding fibers...

  9. Duality of thermal regimes is the distinctive characteristic of plate tectonics since the Neoarchean

    Science.gov (United States)

    Brown, Michael

    2006-11-01

    Ultrahigh-temperature (UHT) granulite metamorphism is documented predominantly in the Neoarchean to Cambrian rock record, but UHT granulite metamorphism also may be inferred at depth in Cenozoic orogenic systems. The first occurrence of UHT granulite metamorphism in the record signifies a change in geodynamics that generated transient sites of very high heat flow. Many UHT granulite metamorphic belts may have developed in settings analogous to modern continental backarcs; on a warmer Earth, destruction of oceans floored by thinner lithosphere may have generated hotter backarcs than those associated with the modern Pacific ring of fire. Medium-temperature eclogite high- pressure (EHP) granulite metamorphism is documented in the Neoarchean rock record and at intervals throughout the Proterozoic and Paleozoic record. EHP granulite metamorphic belts are complementary to UHT granulite metamorphic belts in that they are generally inferred to record subduction-to-collision orogenesis. Blueschists become evident in the Neoproterozoic rock record, but lawsonite blueschist eclogite metamorphism (high pressure [HP]) and ultrahigh-pressure metamorphism (UHP) characterized by coesite or diamond are predominantly Phanerozoic phenomena. HP-UHP metamorphism registers the low thermal gradients and deep subduction of continental crust during the early stage of subduction-to-collision orogenesis. A duality of metamorphic belts—reflecting a duality of thermal regimes—appears in the record only since the Neoarchean Era. A duality of thermal regimes is the hallmark of modern plate tectonics, and the duality of metamorphic belts is the characteristic imprint of plate tectonics in the rock record. The occurrence of both UHT and EHP granulite metamorphism since the Neoarchean marks the onset of a “Proterozoic plate tectonics” regime, which evolved during a Neoproterozoic transition to the modern plate tectonics regime, characterized by colder subduction as chronicled by HP

  10. Thermal and mechanical properties of selected 3D printed thermoplastics in the cryogenic temperature regime

    International Nuclear Information System (INIS)

    Weiss, K-P; Bagrets, N; Lange, C; Goldacker, W; Wohlgemuth, J

    2015-01-01

    Insulating materials for use in cryogenic boundary conditions are still limited to a proved selection as Polyamid, Glasfiber reinforced resins, PEEK, Vespel etc. These materials are usually formed to parts by mechanical machining or sometimes by cast methods. Shaping complex geometries in one piece is limited. Innovative 3D printing is now an upcoming revolutionary technology to construct functional parts from a couple of thermoplastic materials as ABS, Nylon and others which possess quite good mechanical stability and allow realizing very complex shapes with very subtle details. Even a wide range of material mixtures is an option and thermal treatments can be used to finish the material structure for higher performance. The use of such materials in cryogenic environment is very attractive but so far poor experience exists. In this paper, first investigations of the thermal conductivity, expansion and mechanical strength are presented for a few selected commercial 3D material samples to evaluate their application prospects in the cryogenic temperature regime. (paper)

  11. Thermal stability of spent coffee ground polysaccharides: galactomannans and arabinogalactans.

    Science.gov (United States)

    Simões, Joana; Maricato, Elia; Nunes, Fernando M; Domingues, M Rosário; Coimbra, Manuel A

    2014-01-30

    In order to better understand the thermal stability of spent coffee grounds (SCG) galactomannans and arabinogalactans and the reactions that can occur upon roasting, long term isothermal exposures, up to 3h, were performed at 160, 180, 200, 220, and 240 °C. The resultant products were analysed according to the sugars and linkage composition and also by electrospray mass spectrometry. Galactomannans did not loss mass at T ≤ 200 °C during exposures up to 3h whereas the arabinogalactans showed that thermal stability only for T ≤ 180 °C. This was in accordance with the estimated activation energies of their thermal decomposition of 138 kJ/mol and 94 kJ/mol, respectively. The roasting of galactomannans promoted the formation of new glycosidic linkages, with occurrence of 2-, 6-, 2,3-, 2,6-, 3,6-, 2,3,6-, 3,4,6-linked mannose residues, 3,4,6-linked galactose residues, and terminally-linked glucose residues, observed by methylation analysis. Depolymerisation and formation of anhydrohexose residues at the reducing end and mannose-glucose isomerisation were also observed. The roasting of galactomannans at 200 °C promoted their solubility in water upon alkali extraction and neutralisation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Continental Scientific Drilling (CSD): Technology Barriers to Deep Drilling Studies in Thermal Regimes

    Energy Technology Data Exchange (ETDEWEB)

    Kolstad, George A.; Rowley, John C.

    1987-01-16

    This report is the proceedings of a workshop. The primary thrust of these discussion was to identify the major key technology barriers to the Department of Energy (DOE) supported Thermal Regimes CSD projects and to set priorities for research and development. The major technological challenge is the high temperature to be encountered at depth. Specific problems derived from this issue were widely recognized among the participants and are reflected in this summary. A major concern for the projected Thermal Regimes CSD boreholes was the technology required for continuous coring, in contrast to that required for drilling without core or spot coring. Current commercial technology bases for these two techniques are quite different. The DOE has successfully fielded projects that used both technologies, i.e, shallow continuous coring (Inyo Domes and Valles Caldera) and deeper drilling with spot cores (Imperial Valley-SSSDP). It was concluded that future scientific objectives may still require both approaches, but continuous coring is the most likely requirement in the near term. (DJE-2005)

  13. Descriptors of natural thermal regimes in streams and their responsiveness to change in the Pacific Northwest of North America

    Science.gov (United States)

    Arismendi, Ivan; Johnson, Sherri L.; Dunham, Jason B.; Haggerty, Roy

    2013-01-01

    1. Temperature is a major driver of ecological processes in stream ecosystems, yet the dynamics of thermal regimes remain poorly described. Most work has focused on relatively simple descriptors that fail to capture the full range of conditions that characterise thermal regimes of streams across seasons or throughout the year. 2. To more completely describe thermal regimes, we developed several descriptors of magnitude, variability, frequency, duration and timing of thermal events throughout a year. We evaluated how these descriptors change over time using long-term (1979–2009), continuous temperature data from five relatively undisturbed cold-water streams in western Oregon, U.S.A. In addition to trends for each descriptor, we evaluated similarities among them, as well as patterns of spatial coherence, and temporal synchrony. 3. Using different groups of descriptors, we were able to more fully capture distinct aspects of the full range of variability in thermal regimes across space and time. A subset of descriptors showed both higher coherence and synchrony and, thus, an appropriate level of responsiveness to examine evidence of regional climatic influences on thermal regimes. Most notably, daily minimum values during winter–spring were the most responsive descriptors to potential climatic influences. 4. Overall, thermal regimes in streams we studied showed high frequency and low variability of cold temperatures during the cold-water period in winter and spring, and high frequency and high variability of warm temperatures during the warm-water period in summer and autumn. The cold and warm periods differed in the distribution of events with a higher frequency and longer duration of warm events in summer than cold events in winter. The cold period exhibited lower variability in the duration of events, but showed more variability in timing. 5. In conclusion, our results highlight the importance of a year-round perspective in identifying the most responsive

  14. Review of Nuclear Thermal Propulsion Ground Test Options

    Science.gov (United States)

    Coote, David J.; Power, Kevin P.; Gerrish, Harold P.; Doughty, Glen

    2015-01-01

    High efficiency rocket propulsion systems are essential for humanity to venture beyond the moon. Nuclear Thermal Propulsion (NTP) is a promising alternative to conventional chemical rockets with relatively high thrust and twice the efficiency of highest performing chemical propellant engines. NTP utilizes the coolant of a nuclear reactor to produce propulsive thrust. An NTP engine produces thrust by flowing hydrogen through a nuclear reactor to cool the reactor, heating the hydrogen and expelling it through a rocket nozzle. The hot gaseous hydrogen is nominally expected to be free of radioactive byproducts from the nuclear reactor; however, it has the potential to be contaminated due to off-nominal engine reactor performance. NTP ground testing is more difficult than chemical engine testing since current environmental regulations do not allow/permit open air testing of NTP as was done in the 1960's and 1970's for the Rover/NERVA program. A new and innovative approach to rocket engine ground test is required to mitigate the unique health and safety risks associated with the potential entrainment of radioactive waste from the NTP engine reactor core into the engine exhaust. Several studies have been conducted since the ROVER/NERVA program in the 1970's investigating NTP engine ground test options to understand the technical feasibility, identify technical challenges and associated risks and provide rough order of magnitude cost estimates for facility development and test operations. The options can be divided into two distinct schemes; (1) real-time filtering of the engine exhaust and its release to the environment or (2) capture and storage of engine exhaust for subsequent processing.

  15. The influence of thermal regime on gasoline direct injection engine performance and emissions

    Science.gov (United States)

    Leahu, C. I.; Tarulescu, S.

    2016-08-01

    This paper presents the experimental research regarding to the effects of a low thermal regime on fuel consumption and pollutant emissions from a gasoline direct injection (GDI) engine. During the experimental researches, the temperature of the coolant and oil used by the engine were modified 4 times (55, 65, 75 and 85 oC), monitoring the effects over the fuel consumption and emissions (CO2, CO and NOx). The variations in temperature of the coolant and oil have been achieved through AVL coolant and oil conditioning unit, integrated in the test bed. The obtained experimental results reveals the poor quality of exhaust gases and increases of fuel consumption for the gasoline direct injection engines that runs outside the optimal ranges for coolant and oil temperatures.

  16. Numerical modeling of thermal regime in inland water bodies with field measurement data

    Science.gov (United States)

    Gladskikh, D.; Sergeev, D.; Baydakov, G.; Soustova, I.; Troitskaya, Yu.

    2018-01-01

    Modification of the program complex LAKE, which is intended to compute the thermal regimes of inland water bodies, and the results of its validation in accordance with the parameters of lake part of Gorky water reservoir are reviewed in the research. The modification caused changing the procedure of input temperature profile assignment and parameterization of surface stress on air-water boundary in accordance with the consideration of wind influence on mixing process. Also the innovation consists in combined methods of gathering meteorological parameters from files of global meteorological reanalysis and data of hydrometeorological station. Temperature profiles carried out with CTD-probe during expeditions in the period 2014-2017 were used for validation of the model. The comparison between the real data and the numerical results and its assessment based on time and temperature dependences in control points, correspondence of the forms of the profiles and standard deviation for all performed realizations are provided. It is demonstrated that the model reproduces the results of field measurement data for all observed conditions and seasons. The numerical results for the regimes with strong mixing are in the best quantitative and qualitative agreement with the real profiles. The accuracy of the forecast for the ones with strong stratification near the surface is lower but all specificities of the forms are correctly reproduced.

  17. STUDY OF PARAMETERS OF THE ICE-THERMAL REGIME OF LAKE BAIKAL USING REMOTE METHODS

    Directory of Open Access Journals (Sweden)

    E. N. Sutyrina

    2017-01-01

    Full Text Available The surface temperature of the water and the characteristics of the ice cover are important parameters of the state of the ecosystem of the lake and one of the most important indicators that allow us to identify climate change. Dimensions of Lake Baikal with an area of 31.7 thousand sq. kilometers make it reasonable to use the data of satellite remote sensing to study the characteristics of its ice-thermal regime. The purpose of this investigation was to study the features of the spatiotemporal distribution of the parameters of the ice-thermal regime of Lake Baikal using AVHRR (Advanced Very High Resolution Radiometer radiometer data for the period of 1998-2016.The paper describes the developed approach to mapping the stages of melting and destruction of the snow-ice cover on Baikal Lake in the spring and the method for mapping the surface temperature of the lake in an ice-free period according to AVHRR data. Samples of compiled schematic maps of the ice situation and of temperature distribution on the lake surface are given. Based on the obtained cartographic materials, the specificity of ice disappearance of the water areas of the Southern, Central and Northern basins of Lake Baikal has been studied. And it was found that the interannual fluctuations in the timing of the ice disappearance on the given water areas are in antiphase with the interannual fluctuations in the value of the Arctic Oscillation Index. Schematic temperature maps were used to study the intra-annual and interannual variability in the temperature distribution of Lake Baikal’s surface and it was revealed that the greatest interannual variability of temperature on its surface is observed in August, which is characterized by the maximum warming of the surface of the water body. Also, the contribution of several significant factors to the formation of temperature fields on the surface of Lake Baikal was estimated. 

  18. Numerical investigations of microtopographic influence on the near surface thermal regime and thermokarst development in ice wedge polygons

    Science.gov (United States)

    Abolt, C.; Young, M.; Atchley, A. L.; Harp, D. R.

    2017-12-01

    Permafrost degradation in ice wedge polygon terrain has accelerated in the last three decades, resulting in drastic changes to tundra hydrology which may impact rates of soil organic carbon mobilization. The goal of this research is to determine to what extent the near surface thermal regime, and hence the vulnerability of the upper permafrost, may be controlled by surface topography in ice wedge polygons. The central hypothesis is that energy is preferentially transferred into the polygon subsurface in summer at low, wet zones (such as low-centered polygon centers and troughs), then released to the atmosphere in winter through elevated zones (such as rims) that are less insulated by snowpack. Disturbance to the approximate balance between these seasonal energy fluxes may help explain the onset and development of thermokarst. In this work, we present a numerical model of thermal hydrology in a low-centered polygon near Prudhoe Bay, Alaska, constructed within the Advanced Terrestrial Simulator, a state of the art code that couples a meteorologically driven surface energy balance with equations for surface and subsurface conservation of mass and energy. The model is calibrated against a year of daily ground temperature observations throughout the polygon and used to quantify meter-scale zonation in the subsurface thermal budget. The amount of relief in the rims and the trough of the simulated polygon is then manipulated, and simulations are repeated including a pulse of one warm year, to explore the extent to which topography may influence the response of permafrost to increased air temperatures. Results suggest that nearly 25% of energy entering the ground at the polygon center during summer may be released back to the atmosphere through the rims in winter, producing a modest effect on active layer thickness throughout the polygon. Simulated polygons with deeper, wetter troughs have only marginally thicker active layers than other polygons in average years, but are

  19. Thermal-Mechanical Regime beneath Tarim Basin, Northwestern China and its Implications for Cenozoic Tectonics

    Science.gov (United States)

    Liu, S.; Wang, L.

    2005-12-01

    As one of the super-large scale sedimentary basins in China, the Tarim basin is also the strategic basement for Chinese `Natural gas transportation from west to east' project. To know its thermal regime is vital for understanding the deformation and oil gas resource in Tarim basin. Integrated the abundant data of geotemperature and rock thermophysical parameters collected and measured in the basin with corresponding geothermal modeling, here we present the characteristics of geotemperature field, thermal evolution and lithospheric thermo-rheological structure of the Tarim basin, along with the implications for formation and deformation of basin and hydrocarbon reservoir. Our results show that the average present-day heat flow of the basin is about 45 mW/m2 and 18-20°/km for geotemperature gradient, respectively. The basin is characterized by lower temperature in a whole. Lateral heterogeneities exist for the distribution of geotemperature field in the basin. The structural units of basin differ much in the geothermal features; generally, the depression areas are of relatively low geotemperature while high for those uplifts and highs in the basin. Thermal evolution modeling of the basin indicated that it has experienced four different phases since basin formation as follows: high heat flow phase from Sinian to Ordovician, thermal attenuation phase during Silurian to late Paleozoic, then stable thermal evolution phase in Mesozoic, and flexural deformation of lithosphere in Cenozoic. The thickness of the thermal lithosphere of basin is 168-192 km, and 25-28km for the crustal brittle-ductile transition depth; the total lithospheric strength is 1.6-7.8*10**13 N/m. The lithosphere beneath basin is characterized by the rigid block with low temperature but large strength, and deform in a whole. Responded to the far field effect of the Cenozoic India-Eurasia collision, the lithosphere beneath Tarim basin is characterized by flexure deformation, resulting in the intensive

  20. Thermal electron transport in regimes with low and negative magnetic shear in Tore Supra

    International Nuclear Information System (INIS)

    Voitsekhovitch, I.; Litaudon, X.; Moreau, D.; Aniel, T.; Becoulet, A.; Erba, M.; Joffrin, E.; Kazarian-Vibert, F.; Peysson, Y.

    1997-01-01

    The magnetic shear effect on thermal electron transport is studied in a large variety of non-inductive plasmas in Tore Supra. An improved confinement in the region of low and negative shear was observed and quantified with an exponential dependence on the magnetic shear (Litaudon, et al., Fusion Energy 1996 (Proc. 16th Int. Conf. Montreal, 1996), Vol. 1, IAEA, Vienna (1997) 669). This is interpreted as a consequence of a decoupling of the global modes (Romanelli and Zonca, Phys. Fluids B 5 (1993) 4081) that are thought to be responsible for anomalous transport. This dependence is proposed in order to complete the Bohm-like L mode local electron thermal diffusivity so as to describe the transition from Bohm-like to gyroBohm transport in the plasma core. The good agreement between the predictive simulations of the different Tore Supra regimes (hot core lower hybrid enhanced performance, reversed shear plasmas and combined lower hybrid current drive and fast wave electron heating) and experimental data provides a basis for extrapolation of this magnetic shear dependence in the local transport coefficients to future machines. As an example, a scenario for non-inductive current profile optimization and control in ITER is presented. (author)

  1. Thermal electron transport in the regimes with low and negative magnetic shear on tore supra

    International Nuclear Information System (INIS)

    Voitsekhovitch, I.; Litaudon, X.; Moreau, D.; Aniel, T.; Becoulet, A.; Erba, M.; Joffrin, E.; Kazarian-Vibert, F.; Peysson, Y.

    1997-04-01

    The magnetic shear effect on the thermal electron transport is studied in a large variety of non-inductive plasmas of Tore Supra. An improved confinement in the region of low and negative shear was observed and quantified with an exponential dependence on the magnetic shear [Litaudon et al. in Plasma Physics and Controlled Nuclear Fusion Research, 1996, Montreal (International Atomic Energy Agency, Vienna, 1997) to be published]. This is interpreted as the consequence of a decoupling of the global modes [Romanelli and Zonka, Phys. Fluids B5 (1993), 4081] which are thought to be responsible for anomalous transport. This dependence is proposed to complete the Bohm-like L-mode local electron thermal diffusivity to describe the transition from the Bohm-like to the gyro-Bohm transport in the plasma core. The good agreement between the predictive simulations of the different Tore Supra regimes (hot core lower hybrid enhanced performance, reversed shear plasmas and combined lower hybrid current drive and fast wave electron heating) and experimental data gives a basis for the extrapolation of this magnetic shear dependence in the local transport coefficients for future machines. As an example a scenario for non-inductive current profile optimisation and control in ITER is presented. (author)

  2. Uncovering the benefits of fluctuating thermal regimes on cold tolerance of drosophila flies by combined metabolomic and lipidomic approach

    Czech Academy of Sciences Publication Activity Database

    Colinet, H.; Renault, D.; Javal, M.; Berková, Petra; Šimek, Petr; Košťál, Vladimír

    2016-01-01

    Roč. 1861, č. 11 (2016), s. 1736-1745 ISSN 1388-1981 R&D Projects: GA ČR GA13-18509S Institutional support: RVO:60077344 Keywords : cold stress * fluctuating thermal regimes * recovery Subject RIV: ED - Physiology Impact factor: 5.547, year: 2016 http://www.sciencedirect.com/science/article/pii/S1388198116302281

  3. Soil thermal regime and geomorphogenesis at Fuentes Carrionas massif (Cantabrian Range, NW Iberian Peninsula).

    Science.gov (United States)

    Pellitero, Ramon; Serrano Cañadas, Enrique

    2015-04-01

    Fuentes Carrionas is a massif within the Cantabrian Range, in NW Iberian Peninsula. Its altitude ranges between 1400 and 2500 meters and its climate is an oceanic/Mediterranean transition one, with cold temperatures and heavy snowfall in the winter/early spring season, and a warm and dry summer season. Due to its outstanding altitude and lithological variety in the Cantabrian Range context, Fuentes Carrionas holds some periglacial activity (gelifluction, frost shattering) which is absent elsewhere in NW Iberian Peninsula. This work is relates the soil thermal regime across the mountain gradient to landforms formation. 14 thermometers (11 i-button, protected in a plastic can, and three UTL data loggers) were buried at a shallow depth (10 cm.) between autumn 2009 and summer 2012. 12 thermometers were placed between 1900 and 2400 m.a.s.l. at 250 meters altitude interval at the four main aspects. Two additional thermometers were place in the Curavacas N face for permafrost identification. Thermometers were calibrated to yield a measurement every 6 hours starting from 8 AM during one year's time. Data was collected annually in the summer season. Some additional soil temperature data was obtained from an external project in the same area for the 2007-2009 interval. In this case thermometers were "Hobbo" model, and they were also buried to a shallow depth. Results show a permafrost free mountain range. Annual average soil temperatures range between 1 and 8 degrees Celsius. Snow pack appears as a decisive factor in winter temperatures, as the zero curtain effect can be tracked in many cases. Snow cover patterns show a distinctive behavior between S and N aspects, with a 3 months snow cover on the southern faces and between 6 and 9 at the northern analogues. This cover has a relevant impact on geomorphological processes. There is a clear relation between spring snow melt and solifluction or channelized erosion. Also, snow cover prevents the occurrence of freeze/thaw cycles

  4. Thermal regime of the lithosphere and prediction of seismic hazard in the Caspian region

    International Nuclear Information System (INIS)

    Levin, L.E.; Solodilov, L.N.; Kondorskaya, N.V.; Gasanov, A.G; Panahi, B.M.

    2002-01-01

    Full text : Prediction of seicmicity is one of elements of ecology hazard warning. In this collective research, it is elaborated in three directions : quantitative estimate of regional faults by level of seismic activity; ascertainment of space position of earthquake risk zones, determination of high seismic potential sites for the period of the next 3-5 years. During elaboration of prediction, it takes into account that peculiar feature all over the is determined by relationship of about 90 percent of earthquake hypocenters and released energy of seismic waves with elactic-brittle ayer of the lithosphere. Concetration of earthquakes epicenters is established predominantly in zones of complex structure of elastic-brittle layer where gradient of it thickness is 20-30 km. Directions of hypocenters migration in the plastic-viscous layer reveal a space position of seismic dangerous zones. All this provides a necessity for generalization of data on location of earthquakes epicenters; determination of their magnitudes, space position of regional faults and heat flow with calculation of thermal regime being made for clarification of the lithosphere and elastic-brittle thickness variations separately. General analysis includes a calculation of released seismic wave energy and determination of peculiar features of its distribution in the entire region and also studies of hypocenters migration in the plastic-viscous layer of the litosphere in time.

  5. Thermal-diffusional Instability in White Dwarf Flames: Regimes of Flame Pulsation

    Science.gov (United States)

    Xing, Guangzheng; Zhao, Yibo; Modestov, Mikhail; Zhou, Cheng; Gao, Yang; Law, Chung K.

    2017-05-01

    Thermal-diffusional pulsation behaviors in planar as well as outwardly and inwardly propagating white dwarf (WD) carbon flames are systematically studied. In the 1D numerical simulation, the asymptotic degenerate equation of state and simplified one-step reaction rates for nuclear reactions are used to study the flame propagation and pulsation in WDs. The numerical critical Zel’dovich numbers of planar flames at different densities (ρ = 2, 3, and 4 × 107 g cm-3) and of spherical flames (with curvature c = -0.01, 0, 0.01, and 0.05) at a particular density (ρ = 2 × 107 g cm-3) are presented. Flame front pulsation in different environmental densities and temperatures are obtained to form the regime diagram of pulsation, showing that carbon flames pulsate in the typical density of 2 × 107 g cm-3 and temperature of 0.6 × 109 K. While being stable at higher temperatures, at relatively lower temperatures, the amplitude of the flame pulsation becomes larger. In outwardly propagating spherical flames the pulsation instability is enhanced and flames are also easier to quench due to pulsation at small radius, while the inwardly propagating flames are more stable.

  6. Simulation of regimes of convection and plume dynamics by the thermal Lattice Boltzmann Method

    Science.gov (United States)

    Mora, Peter; Yuen, David A.

    2018-02-01

    We present 2D simulations using the Lattice Boltzmann Method (LBM) of a fluid in a rectangular box being heated from below, and cooled from above. We observe plumes, hot narrow upwellings from the base, and down-going cold chutes from the top. We have varied both the Rayleigh numbers and the Prandtl numbers respectively from Ra = 1000 to Ra =1010 , and Pr = 1 through Pr = 5 ×104 , leading to Rayleigh-Bénard convection cells at low Rayleigh numbers through to vigorous convection and unstable plumes with pronounced vortices and eddies at high Rayleigh numbers. We conduct simulations with high Prandtl numbers up to Pr = 50, 000 to simulate in the inertial regime. We find for cases when Pr ⩾ 100 that we obtain a series of narrow plumes of upwelling fluid with mushroom heads and chutes of downwelling fluid. We also present simulations at a Prandtl number of 0.7 for Rayleigh numbers varying from Ra =104 through Ra =107.5 . We demonstrate that the Nusselt number follows power law scaling of form Nu ∼Raγ where γ = 0.279 ± 0.002 , which is consistent with published results of γ = 0.281 in the literature. These results show that the LBM is capable of reproducing results obtained with classical macroscopic methods such as spectral methods, and demonstrate the great potential of the LBM for studying thermal convection and plume dynamics relevant to geodynamics.

  7. Thermal-diffusional Instability in White Dwarf Flames: Regimes of Flame Pulsation

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Guangzheng; Zhao, Yibo; Zhou, Cheng; Gao, Yang; Law, Chung K. [Center for Combustion Energy, Tsinghua University, Beijing 100084 (China); Modestov, Mikhail, E-mail: gaoyang-00@mails.tsinghua.edu.cn [Nordita, KTH Royal Institute of Technology and Stockholm University, SE-10691, Stockholm (Sweden)

    2017-05-20

    Thermal-diffusional pulsation behaviors in planar as well as outwardly and inwardly propagating white dwarf (WD) carbon flames are systematically studied. In the 1D numerical simulation, the asymptotic degenerate equation of state and simplified one-step reaction rates for nuclear reactions are used to study the flame propagation and pulsation in WDs. The numerical critical Zel’dovich numbers of planar flames at different densities ( ρ = 2, 3, and 4 × 10{sup 7} g cm{sup −3}) and of spherical flames (with curvature c = −0.01, 0, 0.01, and 0.05) at a particular density ( ρ = 2 × 10{sup 7} g cm{sup −3}) are presented. Flame front pulsation in different environmental densities and temperatures are obtained to form the regime diagram of pulsation, showing that carbon flames pulsate in the typical density of 2 × 10{sup 7} g cm{sup −3} and temperature of 0.6 × 10{sup 9} K. While being stable at higher temperatures, at relatively lower temperatures, the amplitude of the flame pulsation becomes larger. In outwardly propagating spherical flames the pulsation instability is enhanced and flames are also easier to quench due to pulsation at small radius, while the inwardly propagating flames are more stable.

  8. Optimizing Fluctuating Thermal Regime Storage of Developing Megachile rotundata (Hymenoptera: Megachilidae).

    Science.gov (United States)

    Rinehart, Joseph P; Yocum, George D; Kemp, William P; Bowsher, Julia H

    2016-03-18

    The alfalfa leafcutting bee, Megachile rotundata (F.), is the primary pollinator for alfalfa seed production in North America. Under current management practice, developing pupae are incubated at 29-30°C until the adults emerge for pollination. If unfavorable spring weather delays peak alfalfa bloom, managers will cool pupae to slow development, which can increase mortality and causes sublethal effects. Previously, we demonstrated that exposure to a fluctuating thermal regime (FTR) increases survival and extends the viable storage period. To determine the optimal conditions for FTR during storage of developing M. rotundata, we examined four variables: temperature of the daily warm pulse, duration of the warm pulse, number of weeks exposed to the FTR treatment, and developmental stage of the bee. Survival was measured by successful eclosion to the adult stage. Under all conditions, exposure to FTR increased survival compared with exposure to a constant 6°C. When the temperature of the daily warm pulse was 20-25°C from a base temperature of 6°C, and the pulse duration was extended to 3 h, survival rates were as high as those observed under standard storage conditions (29°C). Under this FTR storage protocol, bee managers can delay emergence for ∼8 wk without significant decreases in survival. Our findings have substantial economic implications for bee management and alfalfa seed production by increasing the flexibility and efficiency of M. rotundata adult emergence. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the United States.

  9. Thermal Regime of A Deep Temperate Lake and Its Response to Climate Change: Lake Kuttara, Japan

    Directory of Open Access Journals (Sweden)

    Kazuhisa A. Chikita

    2018-02-01

    Full Text Available A deep temperate lake, Lake Kuttara, Hokkaido, Japan (148 m deep at maximum was completely ice-covered every winter in the 20th century. However, ice-free conditions of the lake over winter occurred three times in the 21st century, which is probably due to global warming. In order to understand how thermal regime of the lake responds to climate change, a change in lake mean water temperature from the heat storage change was calculated by integrating observed water temperature over water depths and by numerical calculation of heat budget components based on hydrometeorological data. As a result, a temporal variation of lake mean water temperature from the heat budget calculation was very reasonable to that from the observed water temperature (determination coefficient R2 = 0.969. The lowest lake mean temperature for non-freeze was then evaluated at −1.87 °C, referring to the zero level at 6.80 °C. The 1978–2017 data at a meteorological station near Kuttara indicated that there are significant (less than 5% level long-term trends for air temperature (+0.024 °C/year and wind speed (−0.010 m/s/year. In order to evaluate the effects of climate change on freeze-up patterns, a sensitivity analysis was carried out for the calculated lake mean water temperature. It is noted that, after two decades, the lake could be ice-free once per every two years.

  10. A geospatial risk assessment model for leprosy in Ethiopia based on environmental thermal-hydrological regime analysis

    Directory of Open Access Journals (Sweden)

    Azeb Tadesse Argaw

    2006-11-01

    Full Text Available Geospatial methods were used to study the associations of the environmental thermal-hydrological regime with leprosy prevalence in the Oromia and Amhara regions of Ethiopia. Prediction models were developed that indicated leprosy prevalence was related to: (i long-term normal climate grid data on temperature and moisture balance (rain/potential evapo-transpiration; (ii satellite surveillance data on the Normalized Difference Vegetation Index (NDVI and daytime earth surface temperature (Tmax from the Advanced Very High Resolution Radiometer (AVHRR; and (iii a Genetic Algorithm Rule-Set Prediction (GARP model based on NDVI and Tmax data in relation to leprosy prevalence data. Our results suggest that vertical transmission is not the only means of acquiring leprosy and support earlier reports that a major factor that governs transmission of leprosy is the viability of Mycobacterium leprae outside the human body which is related to the thermal-hydrologic regime of the environment.

  11. Adaptation to local thermal regimes by crustose coralline algae does not affect rates of recruitment in coral larvae

    Science.gov (United States)

    Siboni, Nachshon; Abrego, David; Evenhuis, Christian; Logan, Murray; Motti, Cherie A.

    2015-12-01

    Crustose coralline algae (CCA) are well known for their ability to induce settlement in coral larvae. While their wide distribution spans reefs that differ substantially in temperature regimes, the extent of local adaptation to these regimes and the impact they have on CCA inductive ability are unknown. CCA Porolithon onkodes from Heron (southern) and Lizard (northern) islands on Australia's Great Barrier Reef (separated by 1181 km) were experimentally exposed to acute or prolonged thermal stress events and their thermal tolerance and recruitment capacity determined. A sudden onset bleaching model was developed to determine the health status of CCA based on the rate of change in the CCA live surface area (LSA). The interaction between location and temperature was significant ( F (2,119) = 6.74, p = 0.0017), indicating that thermally driven local adaptation had occurred. The southern population remained healthy after prolonged exposure to 28 °C and exhibited growth compared to the northern population ( p = 0.022), with its optimum temperature determined to be slightly below 28 °C. As expected, at the higher temperatures (30 and 32 °C) the Lizard Island population performed better that those from Heron Island, with an optimum temperature of 30 °C. Lizard Island CCA displayed the lowest bleaching rates at 30 °C, while levels consistently increased with temperature in their southern counterparts. The ability of those CCA deemed thermally tolerant (based on LSA) to induce Acropora millepora larval settlement was then assessed. While spatial differences influenced the health and bleaching levels of P. onkodes during prolonged and acute thermal exposure, thermally tolerant fragments, regardless of location, induced similar rates of coral larval settlement. This confirmed that recent thermal history does not influence the ability of CCA to induce settlement of A. millepora larvae.

  12. Characterizing effects and benefits of beam defocus on high energy laser performance under thermal blooming and turbulence conditions for air-to-ground engagements

    Science.gov (United States)

    Long, Scott N.

    2008-10-01

    This dissertation makes contributions towards knowledge of optimizing of laser weapon performance when operating in the air-to-ground (ATG) regime in thermal blooming conditions. Wave optics modeling techniques were used to represent laser weapon performance in a high fidelity sense to allow progress to be made toward improving lower-fidelity scaling laws that can be used in systems level analysis which has need for better representations of thermal blooming. Chemical-oxygen iodine laser (COIL) based weapon systems that operate near the ground will experience thermal blooming due to atmospheric absorption if output power is sufficiently high. The thermal lens in the ATG case is predominantly in the far-field of the optical system which puts the problem outside the envelope for most classical phase correction techniques. Focusing the laser beyond the target (defocus) in the air-to-ground regime is shown to improve irradiance at the target and can be thought of as reducing the thermal blooming distortion number, ND, rather than phase correction. Improvement is shown in a baseline scenario presented and all variations from it explored herein. The Breaux ND is examined for potential use in a defocus scaling law, and a correction factor due to Smith (1977), developed for a different context, is proposed to address deficiencies. Optimal defocus settings and expected improvement are presented as a function of Breaux ND. Also, the generally negative interaction between turbulence and thermal blooming is investigated and shown to further limit performance potential of ATG laser weapons. This negative interaction can impact the weapon design trade space and operational methods for minimizing the interaction and thermal blooming are explored in a case study.

  13. Transient modeling of the ground thermal conditions using satellite data in the Lena River delta, Siberia

    Science.gov (United States)

    Westermann, Sebastian; Peter, Maria; Langer, Moritz; Schwamborn, Georg; Schirrmeister, Lutz; Etzelmüller, Bernd; Boike, Julia

    2017-06-01

    Permafrost is a sensitive element of the cryosphere, but operational monitoring of the ground thermal conditions on large spatial scales is still lacking. Here, we demonstrate a remote-sensing-based scheme that is capable of estimating the transient evolution of ground temperatures and active layer thickness by means of the ground thermal model CryoGrid 2. The scheme is applied to an area of approximately 16 000 km2 in the Lena River delta (LRD) in NE Siberia for a period of 14 years. The forcing data sets at 1 km spatial and weekly temporal resolution are synthesized from satellite products and fields of meteorological variables from the ERA-Interim reanalysis. To assign spatially distributed ground thermal properties, a stratigraphic classification based on geomorphological observations and mapping is constructed, which accounts for the large-scale patterns of sediment types, ground ice and surface properties in the Lena River delta. A comparison of the model forcing to in situ measurements on Samoylov Island in the southern part of the study area yields an acceptable agreement for the purpose of ground thermal modeling, for surface temperature, snow depth, and timing of the onset and termination of the winter snow cover. The model results are compared to observations of ground temperatures and thaw depths at nine sites in the Lena River delta, suggesting that thaw depths are in most cases reproduced to within 0.1 m or less and multi-year averages of ground temperatures within 1-2 °C. Comparison of monthly average temperatures at depths of 2-3 m in five boreholes yielded an RMSE of 1.1 °C and a bias of -0.9 °C for the model results. The highest ground temperatures are calculated for grid cells close to the main river channels in the south as well as areas with sandy sediments and low organic and ice contents in the central delta, where also the largest thaw depths occur. On the other hand, the lowest temperatures are modeled for the eastern part, which is an

  14. RESEARCH OF INFLUENCE OF THE HIGH-SPEED THERMAL PROCESSING REGIMES ON STRUCTURE AND MECHANICAL PROPERTIES OF PIPE STEEL 32G2

    Directory of Open Access Journals (Sweden)

    A. I. Gordienko

    2012-01-01

    Full Text Available Researches on influence of high-speed heating temperature, regimes of cooling and temperature of abatement on structure and mechanical properties of pipe steel 32G2 are carried out. Recommendations on the regimes of high-speed thermal processing of steel 32G2 which can be used at manufacturing of seamless pipes are given.

  15. Unmanned Ground Vehicle Perception Using Thermal Infrared Cameras

    Science.gov (United States)

    Rankin, Arturo; Huertas, Andres; Matthies, Larry; Bajracharya, Max; Assad, Christopher; Brennan, Shane; Bellut, Paolo; Sherwin, Gary

    2011-01-01

    TIR cameras can be used for day/night Unmanned Ground Vehicle (UGV) autonomous navigation when stealth is required. The quality of uncooled TIR cameras has significantly improved over the last decade, making them a viable option at low speed Limiting factors for stereo ranging with uncooled LWIR cameras are image blur and low texture scenes TIR perception capabilities JPL has explored includes: (1) single and dual band TIR terrain classification (2) obstacle detection (pedestrian, vehicle, tree trunks, ditches, and water) (3) perception thru obscurants

  16. Thermal regime and potential bedrock weathering in alpine rockwalls of Austria: Results from eight years of monitoring (2006-2014)

    Science.gov (United States)

    Kellerer-Pirklbauer, Andreas; Wecht, Matthias

    2015-04-01

    Bedrock temperature at sites with a minor winter snow cover gives a good indication for the effects of air temperature anomalies on ground thermal conditions as well as for the intensity of near-surface physical weathering in bedrock. In this study we present results from an ongoing bedrock temperature monitoring program initiated in 2006. Within the framework of this program nine surface boreholes in rockwalls with different slope orientations and two additional boreholes at flat bedrock sites were drilled between August and September 2006 and subsequently instrumented. The altogether eleven rock temperature sites (RTS) are located in the alpine periglacial zone of the Austrian Alps at latitude 46°55' to 47°22' and longitude 12°44' to 14°41'. All RTS have been installed in metamorphic rock (5 x mica schist; 6 x gneiss) at elevations between 1960 and 2725 m asl (mean 2491 m asl.). Three temperature sensors (PT1000) have been inserted at each borehole site at vertical depths of 3, 10 and 30-40 cm. At each RTS the three sensors are connected to a 3-channel miniature temperature datalogger (MTD) manufactured by GeoPrecision, Germany. Our analysis focussed on (a) the variation of mean and extreme daily temperatures at the rock surface and at depth, (b) the variation of the daily temperature range, (c) the number of freeze-thaw-cycles (FTC) and (d) effective freeze-thaw cycles for frost shattering (eFTC), (e) the duration and intensity of freeze-thaw-cycles (DI-FTC), (f) the number of hours and days within the so-called frost-cracking-window (FCW), and effects of (g) aspect and (h) snow cover on the thermal regimes in the bedrock. Results show for instance that the number of FTC and eFTC varied substantially during the observation period at all eleven RTS and at all sensor depths. However, this variation differs from site to site related to snow cover condition, elevation and aspect. For instance, at one lower-elevated (2255 m asl) north exposed RTS the number of

  17. Effects of constant and cyclical thermal regimes on growth and feeding of juvenile cutthroat trout of variable sizes

    Science.gov (United States)

    M. H. Meeuwig; J. B. Dunham; J. P. Hayes; G. L. Vinyard

    2004-01-01

    The effects of constant (12, 18, and 24°C) and cyclical (daily variation of 15–21 and 12–24 °C) thermal regimes on the growth and feeding of Lahontan cutthroat trout (Oncorhynchus clarki henshawi) of variable sizes were examined. Higher constant temperatures (i.e., 24°C) and more variable daily temperatures (i.e., 12–24°C daily cycle) negatively...

  18. Sharp transition between thermal and quantum tunneling regimes in magnetization relaxation processes

    Science.gov (United States)

    Tejada, J.; Zhang, X. X.; Barbara, B.

    1993-03-01

    In this paper we describe experiments involving measurements of the dependence on time of the thermoremanence magnetization of 2-dimensional random magnets. The low temperature values for the magnetic viscosity agree well with both current theories of tunneling of the magnetization vector (Chudnovsky et al.) and the work of Grabert et al. who predicted that the transition from classical to quantum regime is rather sharp for undamped systems.

  19. Progeny of Osmia lignaria from distinct regions differ in developmental phenology and survival under a common thermal regime.

    Science.gov (United States)

    Pitts-Singer, Theresa L; Cane, James H; Trostle, Glen

    2014-08-01

    Many insects, including some bees, have extensive subcontinental distributions that can differ in climatic conditions. Within and beyond these distributions, humans intentionally transport beneficial insects, including bees, to non-natal geographic locations. Insects also are experiencing unprecedented climatic change in their resident localities. For solitary bees, we know very little about the adaptive plasticity and geographic variation in developmental physiology that accommodates the different climates experienced within distributional ranges. Osmia lignaria Say (Hymenoptera: Megachilidae) is a widely distributed North American spring-emerging bee being developed as a managed pollinator for tree fruit crops, including almonds. We examined the development and survival of O. lignaria progeny that were descended from populations sourced from southern California, western Washington, and northern Utah, and then were reared together under an hourly and weekly temperature regime simulating those of a California almond-growing region. We found that developmental physiologies of Washington and Utah progeny were generally similar. However, California progeny developed slower, were more metabolically active, and survived better under California conditions than did populations native to regions at higher latitudes. Regardless of geographic origin, cocooned adults managed under prescribed thermal regimes emerged faster and lived longer after wintering. Progeny of parents from different regions exhibited some acclimatory plasticity in developmental phenologies to a novel climatic regime, but overall their responses reflected their geographic origins. This outcome is consistent with their developmental phenologies being largely heritable adaptations to regional climates. Published by Elsevier Ltd.

  20. Thermal radiation effects on magnetohydrodynamic free convection heat and mass transfer from a sphere in a variable porosity regime

    KAUST Repository

    Prasad, Vallampati Ramachandra Ramachandra

    2012-02-01

    A mathematical model is presented for multiphysical transport of an optically-dense, electrically-conducting fluid along a permeable isothermal sphere embedded in a variable-porosity medium. A constant, static, magnetic field is applied transverse to the cylinder surface. The non-Darcy effects are simulated via second order Forchheimer drag force term in the momentum boundary layer equation. The surface of the sphere is maintained at a constant temperature and concentration and is permeable, i.e. transpiration into and from the boundary layer regime is possible. The boundary layer conservation equations, which are parabolic in nature, are normalized into non-similar form and then solved numerically with the well-tested, efficient, implicit, stable Keller-box finite difference scheme. Increasing porosity (ε) is found to elevate velocities, i.e. accelerate the flow but decrease temperatures, i.e. cool the boundary layer regime. Increasing Forchheimer inertial drag parameter (Λ) retards the flow considerably but enhances temperatures. Increasing Darcy number accelerates the flow due to a corresponding rise in permeability of the regime and concomitant decrease in Darcian impedance. Thermal radiation is seen to reduce both velocity and temperature in the boundary layer. Local Nusselt number is also found to be enhanced with increasing both porosity and radiation parameters. © 2011 Elsevier B.V.

  1. Climate change impact on thermal and oxygen regime of shallow lakes

    Directory of Open Access Journals (Sweden)

    Georgiy Kirillin

    2012-02-01

    Full Text Available Among the numerous processes that govern the functioning of a lake ecosystem, the regime of dissolved oxygen (DO is of primary importance. The DO content is strongly affected by the temperature regime, mixing conditions and by the duration of the ice-covered period. These are formed due to atmospheric forcing and are, therefore, subject to variations in regional climate. Despite the large amount of data revealing the physical effect on the biological and chemical regimes in lakes, there is still insufficient understanding, both qualitative and quantitative, of how a lake ecosystem would be affected by changes in the lake temperature and mixing conditions due to changes in the atmospheric forcing. Below, the study of shallow lakes’ response to climatic changes using the coupled FLake–FLakeEco modelling system is presented. The results obtained reveal the extreme vulnerability of the lakes’ ecosystems to changes in atmospheric forcing. In ‘future’ climate the permanent existence of potentially dangerous anaerobic zones in shallow lakes is expected. The projected decreased oxygen concentrations are caused by: (1 the reduced oxygen flux from the atmosphere to the lakes due to increased temperature; and (2 strengthened density stratification of the water columns which would prevent aeration of the near-bottom layers.

  2. An assessment of testing requirement impacts on nuclear thermal propulsion ground test facility design

    International Nuclear Information System (INIS)

    Shipers, L.R.; Ottinger, C.A.; Sanchez, L.C.

    1993-01-01

    Programs to develop solid core nuclear thermal propulsion (NTP) systems have been under way at the Department of Defense (DoD), the National Aeronautics and Space Administration (NASA), and the Department of Energy (DOE). These programs have recognized the need for a new ground test facility to support development of NTP systems. However, the different military and civilian applications have led to different ground test facility requirements. The Department of Energy (DOE) in its role as landlord and operator of the proposed research reactor test facilities has initiated an effort to explore opportunities for a common ground test facility to meet both DoD and NASA needs. The baseline design and operating limits of the proposed DoD NTP ground test facility are described. The NASA ground test facility requirements are reviewed and their potential impact on the DoD facility baseline is discussed

  3. Simulated juvenile salmon growth and phenology respond to altered thermal regimes and stream network shape

    Science.gov (United States)

    Context. Thermally diverse habitats may afford fish protection from climate change by providing opportunities to behaviorally optimize growing conditions. However, it is unclear what role the spatial properties of river networks will play in determining risk. Objectives. We hypot...

  4. Thermal considerations in the cryogenic regime for the BNL double ridge higher order mode waveguide

    Directory of Open Access Journals (Sweden)

    Dhananjay K. Ravikumar

    2017-09-01

    Full Text Available Brookhaven National Laboratory (BNL has proposed to build an electron ion collider (EIC as an upgrade to the existing Relativistic Heavy Ion Collider (RHIC. A part of the new design is to use superconducting radio frequency (SRF cavities for acceleration, which sit in a bath of superfluid helium at a temperature of 2 K. SRF cavities designed for the BNL EIC create a standing electromagnetic wave, oscillating at a fundamental frequency of 647 MHz. Interaction of the charged particle beam with the EM field in the cavity creates higher order modes (HOM of oscillation which have adverse effects on the beam when allowed to propagate down the beam tube. HOM waveguides are thus designed to remove this excess energy which is then damped at room temperature. As a result, these waveguides provide a direct thermal link between room temperature and the superconducting cavities adding a static thermal load. The EM wave propagating through the warmer sections of the waveguide creates an additional dynamic thermal load. This study calculates these thermal loads, concluding that the dynamic load is small in comparison to the static load. Temperature distributions are mapped on the waveguide and the number of heat intercepts required to efficiently manage thermal loads have been determined. In addition, a thermal radiation study has been performed and it is found that this contribution is around three orders of magnitude smaller than the static conduction and dynamic loads.

  5. A quasi-one-dimensional velocity regime of super-thermal electron stream propagation through the solar corona

    International Nuclear Information System (INIS)

    Levin, B.N.

    1984-01-01

    The propagation of an inhomogeneous stream of fast electrons through the corona - the type III radio burst source - is considered. It is shown, that the angular spectrum width of plasma waves excited by the stream is defined both by Landau damping by particles of the diffuse component and by damping (in the region of large phase velocities) by particles of the stream itself having large pitch angles. The regime of quasi-one-dimensional diffusion in the velocity space is realized only in the presence of a sufficiently dense diffuse component of super-thermal particles and only for a sufficiently large inhomogeneity scale of the stream. A large scale of the stream space profile is formed, evidently, close to the region of injection of super-thermal particles. It is the result of 'stripping' of part of the electrons from the stream front to its slower part due to essential non-one-dimensionality of the particle diffusion in velocity space. Results obtained may explain, in particular, the evolution of a stream particle angular spectrum in the generation region of type III radio bursts observed by spacecrafts (Lin et al., 1981). For the relatively low energetic part of the stream, the oblique plasma wave stabilization by a diffuse component results in a quasi-one-dimensional regime of diffusion. The latter conserves the beam-like structure of this part of the stream. (orig.)

  6. Early Life-Stage Responses of a Eurythemal Estuarine Fish, Mummichog (Fundulus hetereoclitus) to Fixed and Fluctuating Thermal Regimes

    Science.gov (United States)

    Shaifer, J.

    2016-02-01

    The mummichog (Fundulus hetereoclitus) is an intertidal spawning fish that ranges from the Gulf of St. Lawrence to northeastern Florida. A notoriously hardy species, adults can tolerate a wide range of temperature typical of inshore, estuarine waters. This experiment assessed how a wide range of constant and fluctuating temperatures affect the survival, development, and condition of embryos and young larvae. Captive adults were provided nightly with spawning substrates that were inspected each morning for fertilized eggs. Young ( 8 hr post-fertilization) embryos (N = 25 per population) were assigned to either one of a wide range of constant temperatures (8 to 34 °C) generated by a thermal gradient block (TGB), or to one of 10 daily oscillating temperature regimes that spanned the TGB's mid temperature (21 °C). Water was changed and populations inspected for mortalities and hatching at 12-hr intervals. Hatch dates and mortalities were recorded, and larvae were either anesthetized and measured for size by analyzing digital images, or evaluated for persistence in a food-free environment. Mummichog embryos withstood all but the coldest constant regimes and the entire range of fluctuating ones although age at hatching varied substantially within and among experimental populations. Embryos incubated at warmer temperatures hatched out earlier and at somewhat smaller sizes than those experiencing cooler temperatures. Temperatures experienced by embryos had an inverse effect on persistence of larvae relying on yolk nutrition alone. Mummichog exhibited an especially plastic response to thermal challenges which reflects the highly variable nursery habitat used by this species.

  7. Air-ground temperature coupling: analysis by means of Thermal Orbits

    Czech Academy of Sciences Publication Activity Database

    Čermák, Vladimír; Bodri, L.

    2016-01-01

    Roč. 6, č. 1 (2016), s. 112-122 ISSN 2160-0414 R&D Projects: GA ČR(CZ) GAP210/11/0183; GA MŠk(CZ) LG13040 Institutional support: RVO:67985530 Keywords : Thermal Orbits * temperature monitoring * air temperature vs ground temperature Subject RIV: DG - Athmosphere Sciences, Meteorology

  8. Characterisation of Ground Thermal and Thermo-Mechanical Behaviour for Shallow Geothermal Energy Applications

    DEFF Research Database (Denmark)

    Vieira, Ana; Alberdi-Pagola, Maria; Christodoulides, Paul

    2017-01-01

    Increasing use of the ground as a thermal reservoir is expected in the near future. Shallow geothermal energy (SGE) systems have proved to be sustainable alternative solutions for buildings and infrastructure conditioning in many areas across the globe in the past decades. Recently novel solution...

  9. Productivity and species composition of algal mat communities exposed to a fluctuating thermal regime

    International Nuclear Information System (INIS)

    Tison, D.L.; Wilde, E.W.; Pope, D.H.; Fliermans, C.B.

    1981-01-01

    Algal mat communities growing in thermal effluents of production nuclear reactors at the Savannah River Plant, near Aiken, SC, are exposed to large temperature fluctuations resulting from reactor operations. Rates of primary production and species composition were monitored at 4 sites along a thermal gradient in a trough microcosm to determine how these large temperature fluctuations affected productivity and algal community structure. Blue-green algae (cyanobacteria) were the only phototrophic primary producers growing in water above 45 0 C. These thermophiles were able to survive and apparently adapt to ambient temperatures when the reactor was shut down. The algal mat communities exposed to 14 C-labeled dissolved organic compounds and a decrease in primary production were observed during periods of thermal fluctuation. The results show that the dominant phototrophs in this artificially heated aquatic habitat have been selected for their abiity to survive large temperature fluctuations and are similar to those of natural hot springs

  10. Thermal and Fluid Modeling of the CRYogenic Orbital TEstbed (CRYOTE) Ground Test Article (GTA)

    Science.gov (United States)

    Piryk, David; Schallhorn, Paul; Walls, Laurie; Stopnitzky, Benny; Rhys, Noah; Wollen, Mark

    2012-01-01

    The purpose of this study was to anchor thermal and fluid system models to data acquired from a ground test article (GTA) for the CRYogenic Orbital TEstbed - CRYOTE. To accomplish this analysis, it was broken into four primary tasks. These included model development, pre-test predictions, testing support at Marshall Space Flight Center (MSFC} and post-test correlations. Information from MSFC facilitated the task of refining and correlating the initial models. The primary goal of the modeling/testing/correlating efforts was to characterize heat loads throughout the ground test article. Significant factors impacting the heat loads included radiative environments, multi-layer insulation (MLI) performance, tank fill levels, tank pressures, and even contact conductance coefficients. This paper demonstrates how analytical thermal/fluid networks were established, and it includes supporting rationale for specific thermal responses seen during testing.

  11. On the simplifications for the thermal modeling of tilting-pad journal bearings under thermoelastohydrodynamic regime

    DEFF Research Database (Denmark)

    Cerda Varela, Alejandro Javier; Fillon, Michel; Santos, Ilmar

    2012-01-01

    The relevance of calculating accurately the oil film temperature build up when modeling tilting-pad journal bearings is well established within the literature on the subject. This work studies the feasibility of using a thermal model for the tilting-pad journal bearing which includes a simplified...

  12. Modeling thermal structure, ice cover regime and sensitivity to climate change of two regulated lakes - a Norwegian case study

    Science.gov (United States)

    Gebre, Solomon; Boissy, Thibault; Alfredsen, Knut

    2013-04-01

    A great number of river and lakes in Norway and the Nordic region at large are regulated for water management such as hydropower production. Such regulations have the potential to alter the thermal and hydrological regimes in the lakes and rivers downstream impacting on river environment and ecology. Anticipated changes as a result of climate change in meteorological forcing data such as air temperature and precipitation cause changes in the water balance, water temperature and ice cover duration in the reservoirs. This may necessitate changes in operational rules as part of an adaptation strategy for the future. In this study, a one dimensional (1D) lake thermodynamic and ice cover model (MyLake) has been modified to take into account the effect of dynamic outflows in reservoirs and applied to two small but relatively deep regulated lakes (reservoirs) in Norway (Follsjøen and Tesse). The objective was to assess climate change impacts on the seasonal thermal characteristics, the withdrawal temperatures, and the reservoir ice cover dynamics with current operational regimes. The model solves the vertical energy balance on a daily time-step driven by meteorological and hydrological forcings: 2m air temperature, precipitation, 2m relative humidity, 10m wind speed, cloud cover, air pressure, solar insolation, inflow volume, inflow temperature and reservoir outflows. Model calibration with multi-seasonal data of temperature profiles showed that the model performed well in simulating the vertical water temperature profiles for the two study reservoirs. The withdrawal temperatures were also simulated reasonably well. The comparison between observed and simulated lake ice phenology (which were available only for one of the reservoirs - Tesse) was also reasonable taking into account the uncertainty in the observational data. After model testing and calibration, the model was then used to simulate expected changes in the future (2080s) due to climate change by considering

  13. A New Regime of Nanoscale Thermal Transport: Collective Diffusion Increases Dissipation Efficiency

    Science.gov (United States)

    2015-04-21

    2007) Frequency dependence of the thermal conductivity of semiconductor alloys . Phys Rev B 76(7):075207. 5. Freedman JP, et al. (2013) Universal...Berkeley National Laboratory, Berkeley, CA 94720 This contribution is part of the special series of Inaugural Articles by members of the National...the heat source is smaller than the mean free path (MFP) of the dominant heat carriers (phonons in dielectric and semiconductor materials) (1–6

  14. Model and measurements of linear mixing in thermal IR ground leaving radiance spectra

    Science.gov (United States)

    Balick, Lee; Clodius, William; Jeffery, Christopher; Theiler, James; McCabe, Matthew; Gillespie, Alan; Mushkin, Amit; Danilina, Iryna

    2007-10-01

    Hyperspectral thermal IR remote sensing is an effective tool for the detection and identification of gas plumes and solid materials. Virtually all remotely sensed thermal IR pixels are mixtures of different materials and temperatures. As sensors improve and hyperspectral thermal IR remote sensing becomes more quantitative, the concept of homogeneous pixels becomes inadequate. The contributions of the constituents to the pixel spectral ground leaving radiance are weighted by their spectral emissivities and their temperature, or more correctly, temperature distributions, because real pixels are rarely thermally homogeneous. Planck's Law defines a relationship between temperature and radiance that is strongly wavelength dependent, even for blackbodies. Spectral ground leaving radiance (GLR) from mixed pixels is temperature and wavelength dependent and the relationship between observed radiance spectra from mixed pixels and library emissivity spectra of mixtures of 'pure' materials is indirect. A simple model of linear mixing of subpixel radiance as a function of material type, the temperature distribution of each material and the abundance of the material within a pixel is presented. The model indicates that, qualitatively and given normal environmental temperature variability, spectral features remain observable in mixtures as long as the material occupies more than roughly 10% of the pixel. Field measurements of known targets made on the ground and by an airborne sensor are presented here and serve as a reality check on the model. Target spectral GLR from mixtures as a function of temperature distribution and abundance within the pixel at day and night are presented and compare well qualitatively with model output.

  15. Ground Thermal Inertia for Energy Efficient Building Design: A Case Study on Food Industry

    Directory of Open Access Journals (Sweden)

    Fernando R. Mazarrón

    2012-02-01

    Full Text Available The search for energy efficient construction solutions is still pending in the agro-food industry, in which a large amount of energy is often consumed unnecessarily when storing products. The main objective of this research is to promote high energy efficiency built environments, which aim to reduce energy consumption in this sector. We analyze the suitability of using the thermal inertia of the ground to provide an adequate environment for the storage and conservation of agro-food products. This research compares different construction solutions based on the use of ground thermal properties, analyzing their effectiveness to decrease annual outdoor variations and provide adequate indoor conditions. The analysis undertaken is based on over five million pieces of data, obtained from an uninterrupted four year monitoring process of various constructions with different levels of thermal mass, ranging from high volume constructions to others lacking this resource. It has been proven that constructive solutions based on the use of ground thermal inertia are more effective than other solutions when reducing the effects of outdoor conditions, even when these have air conditioning systems. It is possible to reach optimal conditions to preserve agro-food products such as wine, with a good design and an adequate amount of terrain, without having to use air conditioning systems. The results of this investigation could be of great use to the agro-food industry, becoming a reference when it comes to the design of energy efficient constructions.

  16. Thermal-Diffusional Instability in White Dwarf Flames: Regimes of Flame Pulsation

    OpenAIRE

    Xing, Guangzheng; Zhao, Yibo; Modestov, Mikhail; Zhou, Cheng; Gao, Yang; Law, Chung K.

    2017-01-01

    Thermal-diffusional pulsation behaviors in planar as well as outwardly and inwardly propagating white dwarf carbon flames are systematically studied. In the 1D numerical simulation, the asymptotic degenerate equation of state and simplified one-step reaction rates for nuclear reactions are used to study the flame propagation and pulsation in white dwarfs. The numerical critical Zel'dovich numbers of planar flames at different densities ($\\rho=2$, 3 and 4$\\times 10^7$~g/cm$^3$) and of spherica...

  17. Characterisation of Ground Thermal and Thermo-Mechanical Behaviour for Shallow Geothermal Energy Applications

    DEFF Research Database (Denmark)

    Vieira, Ana; Alberdi-Pagola, Maria; Christodoulides, Paul

    2017-01-01

    Increasing use of the ground as a thermal reservoir is expected in the near future. Shallow geothermal energy (SGE) systems have proved to be sustainable alternative solutions for buildings and infrastructure conditioning in many areas across the globe in the past decades. Recently novel solutions......-hydro-mechanical behaviour of soil is introduced and discussed. These coupled processes are important for confirming the structural integrity of energy geostructures, but routine methods for parameter determination are still lacking (Energies). Keywords: shallow geothermal systems; soil thermal behaviour; laboratory testing...

  18. Applying measured reflection from the ground to simulations of thermal perfromance of solar collectors

    DEFF Research Database (Denmark)

    Dragsted, Janne; Furbo, Simon

    2009-01-01

    Solar radiation on tilted and vertical surfaces in the Arctic is, in large parts of the year, strongly influenced by reflection from snow. In connection with planning and optimization of energy efficient buildings and solar energy systems in the Arctic, it is important to have an accurate...... and the azimuth of the surface in question. The paper will present an analysis of simulations of the thermal performance of solar collectors using the standard description of the albedo and using the albedo determined by the measurements. It will be elucidated how important an accurate description...... of the reflection from the ground is for the thermal performance of solar collectors....

  19. Ground-based thermal imaging of stream surface temperatures: Technique and evaluation

    Science.gov (United States)

    Bonar, Scott A.; Petre, Sally J.

    2015-01-01

    We evaluated a ground-based handheld thermal imaging system for measuring water temperatures using data from eight southwestern USA streams and rivers. We found handheld thermal imagers could provide considerably more spatial information on water temperature (for our unit one image = 19,600 individual temperature measurements) than traditional methods could supply without a prohibitive amount of effort. Furthermore, they could provide measurements of stream surface temperature almost instantaneously compared with most traditional handheld thermometers (e.g., >20 s/reading). Spatial temperature analysis is important for measurement of subtle temperature differences across waterways, and identification of warm and cold groundwater inputs. Handheld thermal imaging is less expensive and equipment intensive than airborne thermal imaging methods and is useful under riparian canopies. Disadvantages of handheld thermal imagers include their current higher expense than thermometers, their susceptibility to interference when used incorrectly, and their slightly lower accuracy than traditional temperature measurement methods. Thermal imagers can only measure surface temperature, but this usually corresponds to subsurface temperatures in well-mixed streams and rivers. Using thermal imaging in select applications, such as where spatial investigations of water temperature are needed, or in conjunction with stationary temperature data loggers or handheld electronic or liquid-in-glass thermometers to characterize stream temperatures by both time and space, could provide valuable information on stream temperature dynamics. These tools will become increasingly important to fisheries biologists as costs continue to decline.

  20. Concept study of a hydrogen containment process during nuclear thermal engine ground testing

    Directory of Open Access Journals (Sweden)

    Ten-See Wang

    Full Text Available A new hydrogen containment process was proposed for ground testing of a nuclear thermal engine. It utilizes two thermophysical steps to contain the hydrogen exhaust. First, the decomposition of hydrogen through oxygen-rich combustion at higher temperature; second, the recombination of remaining hydrogen with radicals at low temperature. This is achieved with two unit operations: an oxygen-rich burner and a tubular heat exchanger. A computational fluid dynamics methodology was used to analyze the entire process on a three-dimensional domain. The computed flammability at the exit of the heat exchanger was less than the lower flammability limit, confirming the hydrogen containment capability of the proposed process. Keywords: Hydrogen decomposition reactions, Hydrogen recombination reactions, Hydrogen containment process, Nuclear thermal propulsion, Ground testing

  1. Ground Thermal Inertia for Energy Efficient Building Design: A Case Study on Food Industry

    OpenAIRE

    Mazarrón, Fernando R.; Cid-Falceto, Jaime; Cañas, Ignacio

    2012-01-01

    The search for energy efficient construction solutions is still pending in the agro-food industry, in which a large amount of energy is often consumed unnecessarily when storing products. The main objective of this research is to promote high energy efficiency built environments, which aim to reduce energy consumption in this sector. We analyze the suitability of using the thermal inertia of the ground to provide an adequate environment for the storage and conservation of agro-food products. ...

  2. Mathematical modelling of thermal and flow processes in vertical ground heat exchangers

    Directory of Open Access Journals (Sweden)

    Pater Sebastian

    2017-12-01

    Full Text Available The main task of mathematical modelling of thermal and flow processes in vertical ground heat exchanger (BHE-Borehole Heat Exchanger is to determine the unit of borehole depth heat flux obtainable or transferred during the operation of the installation. This assignment is indirectly associated with finding the circulating fluid temperature flowing out from the U-tube at a given inlet temperature of fluid in respect to other operational parameters of the installation.

  3. Redefining thermal regimes to design reserves for coral reefs in the face of climate change.

    Directory of Open Access Journals (Sweden)

    Iliana Chollett

    Full Text Available Reef managers cannot fight global warming through mitigation at local scale, but they can use information on thermal patterns to plan for reserve networks that maximize the probability of persistence of their reef system. Here we assess previous methods for the design of reserves for climate change and present a new approach to prioritize areas for conservation that leverages the most desirable properties of previous approaches. The new method moves the science of reserve design for climate change a step forwards by: (1 recognizing the role of seasonal acclimation in increasing the limits of environmental tolerance of corals and ameliorating the bleaching response; (2 using the best proxy for acclimatization currently available; (3 including information from several bleaching events, which frequency is likely to increase in the future; (4 assessing relevant variability at country scales, where most management plans are carried out. We demonstrate the method in Honduras, where a reassessment of the marine spatial plan is in progress.

  4. Lithospheric structure, composition, and thermal regime of the East European Craton: Implications for the subsidence of the Russian platform

    Science.gov (United States)

    Artemieva, I.M.

    2003-01-01

    A new mechanism for Paleozoic subsidence of the Russian, or East European, platform is suggested, since a model of lithosphere tilting during the Uralian subduction does not explain the post-Uralian sedimentation record. Alternatively, I propose that the Proterozoic and Paleozoic rifting (when a platform-scale Central Russia rift system and a set of Paleozoic rifts were formed) modified the structure and composition of cratonic lithosphere, and these tectono-magmatic events are responsible for the post-Uralian subsidence of the Russian platform. To support this hypothesis, (a) the thermal regime and the thickness of the lithosphere are analyzed, and (b) lithospheric density variations of non-thermal origin are calculated from free-board constraints. The results indicate that Proterozoic and Paleozoic rifting had different effects on the lithospheric structure and composition. (1) Proterozoic rifting is not reflected in the present thermal regime and did not cause significant lithosphere thinning (most of the Russian platform has lithospheric thickness of 150-180 km and the lithosphere of the NE Baltic Shield is 250-300 km thick). Paleozoic rifting resulted in pronounced lithospheric thinning (to 120-140 km) in the southern parts of the Russian platform. (2) Lithospheric density anomalies suggest that Proterozoic-Paleozoic rifting played an important role in the platform subsidence. The lithospheric mantle of the Archean-early Proterozoic part of the Baltic Shield is ??? 1.4 ?? 0.2% less dense than the typical Phanerozoic upper mantle. However, the density deficit in the subcrustal lithosphere of most of the Russian platform is only about (0.4-0.8) ?? 0.2% and decreases southwards to ???0%. Increased densities (likely associated with low depletion values) in the Russian platform suggest strong metasomatism of the cratonic lithosphere during rifting events, which led to its subsidence. It is proposed that only the lower part of the cratonic lithosphere was

  5. Surface energy budget and thermal inertia at Gale Crater: Calculations from ground-based measurements.

    Science.gov (United States)

    Martínez, G M; Rennó, N; Fischer, E; Borlina, C S; Hallet, B; de la Torre Juárez, M; Vasavada, A R; Ramos, M; Hamilton, V; Gomez-Elvira, J; Haberle, R M

    2014-08-01

    The analysis of the surface energy budget (SEB) yields insights into soil-atmosphere interactions and local climates, while the analysis of the thermal inertia ( I ) of shallow subsurfaces provides context for evaluating geological features. Mars orbital data have been used to determine thermal inertias at horizontal scales of ∼10 4  m 2 to ∼10 7  m 2 . Here we use measurements of ground temperature and atmospheric variables by Curiosity to calculate thermal inertias at Gale Crater at horizontal scales of ∼10 2  m 2 . We analyze three sols representing distinct environmental conditions and soil properties, sol 82 at Rocknest (RCK), sol 112 at Point Lake (PL), and sol 139 at Yellowknife Bay (YKB). Our results indicate that the largest thermal inertia I  = 452 J m -2  K -1  s -1/2 (SI units used throughout this article) is found at YKB followed by PL with I  = 306 and RCK with I  = 295. These values are consistent with the expected thermal inertias for the types of terrain imaged by Mastcam and with previous satellite estimations at Gale Crater. We also calculate the SEB using data from measurements by Curiosity's Rover Environmental Monitoring Station and dust opacity values derived from measurements by Mastcam. The knowledge of the SEB and thermal inertia has the potential to enhance our understanding of the climate, the geology, and the habitability of Mars.

  6. Characterisation of Ground Thermal and Thermo-Mechanical Behaviour for Shallow Geothermal Energy Applications

    Directory of Open Access Journals (Sweden)

    Ana Vieira

    2017-12-01

    Full Text Available Increasing use of the ground as a thermal reservoir is expected in the near future. Shallow geothermal energy (SGE systems have proved to be sustainable alternative solutions for buildings and infrastructure conditioning in many areas across the globe in the past decades. Recently novel solutions, including energy geostructures, where SGE systems are coupled with foundation heat exchangers, have also been developed. The performance of these systems is dependent on a series of factors, among which the thermal properties of the soil play a major role. The purpose of this paper is to present, in an integrated manner, the main methods and procedures to assess ground thermal properties for SGE systems and to carry out a critical review of the methods. In particular, laboratory testing through either steady-state or transient methods are discussed and a new synthesis comparing results for different techniques is presented. In situ testing including all variations of the thermal response test is presented in detail, including a first comparison between new and traditional approaches. The issue of different scales between laboratory and in situ measurements is then analysed in detail. Finally, the thermo-hydro-mechanical behaviour of soil is introduced and discussed. These coupled processes are important for confirming the structural integrity of energy geostructures, but routine methods for parameter determination are still lacking.

  7. Tropical Atlantic climate and ecosystem regime shifts during the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Frieling, Joost; Reichart, Gert-Jan; Middelburg, Jack J.; Röhl, Ursula; Westerhold, Thomas; Bohaty, Steven M.; Sluijs, Appy

    2018-01-01

    The Paleocene-Eocene Thermal Maximum (PETM, 56 Ma) was a phase of rapid global warming associated with massive carbon input into the ocean-atmosphere system from a 13C-depleted reservoir. Many midlatitude and high-latitude sections have been studied and document changes in salinity, hydrology and sedimentation, deoxygenation, biotic overturning, and migrations, but detailed records from tropical regions are lacking. Here, we study the PETM at Ocean Drilling Program (ODP) Site 959 in the equatorial Atlantic using a range of organic and inorganic proxies and couple these with dinoflagellate cyst (dinocyst) assemblage analysis. The PETM at Site 959 was previously found to be marked by a ˜ 3.8 ‰ negative carbon isotope excursion (CIE) and a ˜ 4 °C surface ocean warming from the uppermost Paleocene to peak PETM, of which ˜ 1 °C occurs before the onset of the CIE. We record upper Paleocene dinocyst assemblages that are similar to PETM assemblages as found in extratropical regions, confirming poleward migrations of ecosystems during the PETM. The early stages of the PETM are marked by a typical acme of the tropical genus Apectodinium, which reaches abundances of up to 95 %. Subsequently, dinocyst abundances diminish greatly, as do carbonate and pyritized silicate microfossils. The combined paleoenvironmental information from Site 959 and a close-by shelf site in Nigeria implies the general absence of eukaryotic surface-dwelling microplankton during peak PETM warmth in the eastern equatorial Atlantic, most likely caused by heat stress. We hypothesize, based on a literature survey, that heat stress might have reduced calcification in more tropical regions, potentially contributing to reduced deep sea carbonate accumulation rates, and, by buffering acidification, also to biological carbonate compensation of the injected carbon during the PETM. Crucially, abundant organic benthic foraminiferal linings imply sustained export production, likely driven by prokaryotes. In

  8. Tropical Atlantic climate and ecosystem regime shifts during the Paleocene–Eocene Thermal Maximum

    Directory of Open Access Journals (Sweden)

    J. Frieling

    2018-01-01

    Full Text Available The Paleocene–Eocene Thermal Maximum (PETM, 56 Ma was a phase of rapid global warming associated with massive carbon input into the ocean–atmosphere system from a 13C-depleted reservoir. Many midlatitude and high-latitude sections have been studied and document changes in salinity, hydrology and sedimentation, deoxygenation, biotic overturning, and migrations, but detailed records from tropical regions are lacking. Here, we study the PETM at Ocean Drilling Program (ODP Site 959 in the equatorial Atlantic using a range of organic and inorganic proxies and couple these with dinoflagellate cyst (dinocyst assemblage analysis. The PETM at Site 959 was previously found to be marked by a  ∼  3.8 ‰ negative carbon isotope excursion (CIE and a  ∼  4 °C surface ocean warming from the uppermost Paleocene to peak PETM, of which  ∼  1 °C occurs before the onset of the CIE. We record upper Paleocene dinocyst assemblages that are similar to PETM assemblages as found in extratropical regions, confirming poleward migrations of ecosystems during the PETM. The early stages of the PETM are marked by a typical acme of the tropical genus Apectodinium, which reaches abundances of up to 95 %. Subsequently, dinocyst abundances diminish greatly, as do carbonate and pyritized silicate microfossils. The combined paleoenvironmental information from Site 959 and a close-by shelf site in Nigeria implies the general absence of eukaryotic surface-dwelling microplankton during peak PETM warmth in the eastern equatorial Atlantic, most likely caused by heat stress. We hypothesize, based on a literature survey, that heat stress might have reduced calcification in more tropical regions, potentially contributing to reduced deep sea carbonate accumulation rates, and, by buffering acidification, also to biological carbonate compensation of the injected carbon during the PETM. Crucially, abundant organic benthic foraminiferal linings imply

  9. Phonon-engineered thermal transport in Si wires with constant and periodically modulated cross-sections: A crossover between nano- and microscale regimes

    Science.gov (United States)

    Cocemasov, A. I.; Nika, D. L.; Fomin, V. M.; Grimm, D.; Schmidt, O. G.

    2015-07-01

    The transition between nanoscale and microscale thermal transport regime at room temperature in silicon wires with constant and periodically modulated cross-section is theoretically investigated. Extrapolating the calculated thermal conductivity from the nano- to micrometer range, we find the characteristic dimensions of the wires where a crossover between nanoscale and microscale thermal transport occurs. This crossover is observed in both generic (smooth) and cross-section-modulated wires. In case of smooth silicon wires, we reveal a strong dependence of the crossing point position on the boundary roughness. For silicon wires with weak boundary roughness, the crossover occurs at cross-sections ˜60 nm × 300 nm, while for very rough boundaries it occurs at cross-sections ˜150 nm × 750 nm. In case of the periodically modulated wires, the crossover between nano- and microscale regimes occurs at typical cross-sections ˜120 nm × 120 nm of the narrow segment, and it is almost independent of boundary roughness. A strong distinction from the case of smooth wires is attributed (i) to the different trends at the nanometer scale, wherefrom the extrapolation was performed, and (ii) to the different phonon-boundary scattering due to the specific geometry. For modulated silicon wires, the influence of modulation thickness, modulation length, and cross-sectional area on the phonon thermal conductivity at the room temperature is analyzed. A possibility of thermal transport engineering in cross-section-modulated wires by resizing them is revealed in both nano- and microscale regimes. The presented results pave the way towards a better understanding of thermal transport reduction in Si nanowires with engineered diameter modulations and shed light on the crossover between nano- and microscale regimes of thermal transport.

  10. Design of a solar home with BIPV-thermal system and ground source heat pump

    Energy Technology Data Exchange (ETDEWEB)

    Athienitis, A.K. [Concordia Univ., Montreal, PQ (Canada). Dept. of Building, Civil and Environmental Engineering

    2007-07-01

    The design of a 2-storey single family detached solar home in Montreal was discussed. The house was designed to exceed the energy performance of Natural Resources Canada's advanced houses program but be more cost-effective than net zero energy solar homes. Features of the house included a direct passive solar design that emphasized the use of distributed thermal mass in the south-facing part of the ground floor; an open loop building-integrated photovoltaic-thermal (BIPV/T) system; a 2-stage ground-source heat pump with an electronically commutated motor (ECM) fan used to heat and cool air in the house; an auxiliary floor heating system that was integrated in the floor mass of the direct gain zone; and a 2-zone air distribution system controlled by a multizone programmable thermostat. Design of the building focused on the ability to separately control the 2 zones for increased thermal comfort. Heat recovered from the roof was used for domestic hot water preheating as well as to heat the garage and part of the basement. Design flow rate of the BIPV/T roof and estimates of air temperature rise were selected using a 5-section model of the roof. Transient thermal network models were used to size south-facing windows in order to prevent overheating. A 6-node 3-capacitance thermal network model was used to analyze the house and optimize window-mass ratio. The design approach emphasized architectural integration of solar energy collection in the roof, and optimization of the passive solar design of the direct gain area of the house. An efficient geothermal heat pump was also used in the direct gain zone of the house. It was concluded that the installation of a BIPV/T system can be more cost-effective than the addition of insulation in the walls of a solar house. 8 refs., 1 tab., 11 figs.

  11. A case for using ground-based thermal inertia measurements to detect Martian caves.

    Science.gov (United States)

    Groemer, Gernot; Foresta, Luca; Turetschek, Thomas; Bothe, Claudia; Boyd, Andrea; Dinkelaker, Aline; Dissertori, Markus; Fasching, David; Fischer, Monika; Föger, Daniel; Frischauf, Norbert; Fritsch, Lukas; Fuchs, Harald; Gautsch, Christoph; Gerard, Stephan; Goetzloff, Linda; Gołebiowska, Izabella; Gorur, Paavan; Groemer, Gerhard; Groll, Petra; Haider, Christian; Haider, Olivia; Hauth, Eva; Hauth, Stefan; Hettrich, Sebastian; Jais, Wolfgang; Jones, Natalie; Taj-Eddine, Kamal; Karl, Alexander; Kauerhoff, Tilo; Khan, Muhammad Shadab; Kjeldsen, Andreas; Klauck, Jan; Losiak, Anna; Luger, Markus; Luger, Thomas; Luger, Ulrich; McArthur, Jane; Moser, Linda; Neuner, Julia; Orgel, Csilla; Ori, Gian Gabriele; Paternesi, Roberta; Peschier, Jarno; Pfeil, Isabella; Prock, Silvia; Radinger, Josef; Ragonig, Christoph; Ramirez, Barbara; Ramo, Wissam; Rampey, Mike; Sams, Arnold; Sams, Elisabeth; Sams, Sebastian; Sandu, Oana; Sans, Alejandra; Sansone, Petra; Scheer, Daniela; Schildhammer, Daniel; Scornet, Quentin; Sejkora, Nina; Soucek, Alexander; Stadler, Andrea; Stummer, Florian; Stumptner, Willibald; Taraba, Michael; Tlustos, Reinhard; Toferer, Ernst; Winter, Egon; Zanella-Kux, Katja

    2014-05-01

    Martian caves are regarded as one of the most interesting locations in which to search for life on the planet. Data obtained during the MARS2013 expedition at Hamar Laghdad Ridge in the Tafilalt region of Morocco indicate that even small cavities can display thermal behavior that is characteristic for caves. For example, temperature in a cavity equaled 14°C±0.1°C before sunrise, which was higher than the temperature of the ambient air (10°C±0.1°C) and proximate rocks (9°C±0.1°C) at the same time. Within 30 min after sunrise, when the temperature of surrounding rocks corresponded to 15°C, this thermal relationship reversed. Measurements were conducted under simulated spaceflight conditions, including near-real-time interpretation of data that were acquired in a complex flight planning environment. We conclude that using ground-based thermal contrast measurements, in 7-14 μm band before and after sunset, is an effective method for Mars astronauts to identify caves, possibly superior to usage of space-based or ground-penetrating data.

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

    Science.gov (United States)

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

    2017-10-01

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

  13. Spin dynamics of Mn12-acetate in the thermally activated tunneling regime: ac susceptibility and magnetization relaxation

    Science.gov (United States)

    Pohjola, Teemu; Schoeller, Herbert

    2000-12-01

    In this work, we study the spin dynamics of Mn12-acetate molecules in the regime of thermally assisted tunneling. In particular, we describe the system in the presence of a strong transverse magnetic field. Similar to recent experiments, the relaxation time/rate is found to display a series of resonances; their Lorentzian shape is found to stem from the tunneling. The dynamic susceptibility χ(ω) is calculated starting from the microscopic Hamiltonian and the resonant structure manifests itself also in χ(ω). Similar to recent results reported on another molecular magnet, Fe8, we find oscillations of the relaxation rate as a function of the transverse magnetic field when the field is directed along a hard axis of the molecules. This phenomenon is attributed to the interference of the geometrical or Berry phase. We propose susceptibility experiments to be carried out for strong transverse magnetic fields to study these oscillations and for a better resolution of the sharp satellite peaks in the relaxation rates.

  14. Horizontal ground coupled heat pump: Thermal-economic modeling and optimization

    International Nuclear Information System (INIS)

    Sanaye, Sepehr; Niroomand, Behzad

    2010-01-01

    The modeling and optimizing processes of a Ground Coupled Heat Pump (GCHP) with closed Horizontal Ground Heat eXchanger (HGHX) are presented in this paper. After thermal modeling of GCHP including HGHX, the optimum design parameters of the system were estimated by minimizing a defined objective function (total of investment and operation costs) subject to a list of constraints. This procedure was performed applying Genetic Algorithm technique. For given heating/cooling loads and various climatic conditions, the optimum values of saturated temperature/pressure of condenser and evaporator as well as inlet and outlet temperatures of the water source in cooling and heating modes were predicted. Then, for our case study, the design parameters as well as the configuration of HGHX were obtained. Furthermore, the sensitivity analysis of change in the total annual cost of the system and optimum design parameters with the climatic conditions, cooling/heating capacity, and soil type were discussed.

  15. Absorbed Heat-flux Method for Ground Simulation of On-orbit Thermal Environment of Satellite

    Directory of Open Access Journals (Sweden)

    Jeong-Soo Kim

    1999-12-01

    Full Text Available An absorbed heat-flux method for ground simulation of on-orbit thermal environment of satellite is addressed in this paper. For satellite ground test, high vacuum and extremely low temperature of deep space are achieved by space simulation chamber, while spatial environmental heating is simulated by employing the absorbed heat-flux method. The methodology is explained in detail with test requirement and setup implemented on a satellite. Developed heat-load control system is presented with an adjusted PID-control logic and the system schematic realized is shown. A practical and successful application of the heat simulation method to KOMPSAT(Korea Multi-purpose Satellitethermal environmental test is demonstrated, finally.

  16. Use of thermal-infrared imagery in ground-water investigations in Montana

    Science.gov (United States)

    Boettcher, A. J.; Haralick, R. M.

    1977-01-01

    Thermal infrared imagery was used to locate ground-water inflow along three streams and one lake in Montana. The thermal scanner used in May 1972, March 1973, and November 1975 was mounted in a twin-engined aircraft. On the 1973 and 1975 flights, the data were recorded in an analog format on magnetic tape in flight, later were converted to digital format, and were computer processed using an assignment of patterns to indicate differences in water temperature. Output from the image processing program was converted to a temperature map having an isotherm spacing of 0.5 C. Computerization was found to be the most efficient method to manipulate data from lakes, large rivers, and narrow sinuous streams.

  17. Effects and interactions of gallic acid, eugenol and temperature on thermal inactivation of Salmonella spp. in ground chicken

    Science.gov (United States)

    The combined effects of heating temperature (55 to 65C), gallic acid (0 to 2.0%), and eugenol (0 to 2.0%) on thermal inactivation of Salmonella in ground chicken were assessed. Thermal death times were determined in bags submerged in a heated water bath maintained at various set temperatures, follo...

  18. Habitat pollution and thermal regime modify molecular stress responses to elevated temperature in freshwater mussels (Anodonta anatina: Unionidae)

    International Nuclear Information System (INIS)

    Falfushynska, H.; Gnatyshyna, L.; Yurchak, I.; Ivanina, A.; Stoliar, O.; Sokolova, I.

    2014-01-01

    Elevated temperature and pollution are common stressors in freshwater ecosystems. We study cellular stress response to acute warming in Anodonta anatina (Unionidae) from sites with different thermal regimes and pollution levels: a pristine area and an agriculturally polluted site with normal temperature regimes (F and A, respectively) and a polluted site with elevated temperature (N) from the cooling pond of an electrical power plant. Animals were exposed to different temperatures for 14 days and stress response markers were measured in gills, digestive gland and hemocytes. Mussels from site N and A had elevated background levels of lactate dehydrogenase activity indicating higher reliance on anaerobic metabolism for ATP production and/or redox maintenance. Exposure to 25 °C and 30 °C induced oxidative stress (indicated by elevated levels of lipid peroxidation products) in digestive gland and gills of mussels from A and F sites, while in mussels from N sites elevated oxidative stress was only apparent at 30 °C. Temperature-induced changes in levels of antioxidants (superoxide dismutase, metallothioneins and glutathione) were tissue- and population-specific. Acute warming led to destabilization of lysosomal membranes and increased frequencies of nuclear lesions in mussels from F and A sites but not in their counterparts from N site. Elevated temperature led to an increase in the frequency of micronuclei in hemocytes in mussels from F and A sites at 25 °C and 30 °C and in mussels from N site at 30 °C. The mussels from N site also demonstrated better survival at elevated temperature (30 °C) than their counterparts from the F and A sites. Taken together, these data indicate that long-term acclimation and/or adaptation of A. anatina to elevated temperatures result in increased thermotolerance and alleviate stress response to moderate temperature rise. In contrast, extreme warming (30 °C) is harmful to mussels from all populations indicating limit to this induced

  19. Habitat pollution and thermal regime modify molecular stress responses to elevated temperature in freshwater mussels (Anodonta anatina: Unionidae)

    Energy Technology Data Exchange (ETDEWEB)

    Falfushynska, H.; Gnatyshyna, L.; Yurchak, I. [Research Laboratory of Comparative Biochemistry and Molecular Biology, Ternopil National Pedagogical University, Kryvonosa Str 2, 46027 Ternopil (Ukraine); Ivanina, A. [Department of Biological Sciences, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Stoliar, O. [Research Laboratory of Comparative Biochemistry and Molecular Biology, Ternopil National Pedagogical University, Kryvonosa Str 2, 46027 Ternopil (Ukraine); Sokolova, I., E-mail: isokolov@uncc.edu [Department of Biological Sciences, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)

    2014-12-01

    Elevated temperature and pollution are common stressors in freshwater ecosystems. We study cellular stress response to acute warming in Anodonta anatina (Unionidae) from sites with different thermal regimes and pollution levels: a pristine area and an agriculturally polluted site with normal temperature regimes (F and A, respectively) and a polluted site with elevated temperature (N) from the cooling pond of an electrical power plant. Animals were exposed to different temperatures for 14 days and stress response markers were measured in gills, digestive gland and hemocytes. Mussels from site N and A had elevated background levels of lactate dehydrogenase activity indicating higher reliance on anaerobic metabolism for ATP production and/or redox maintenance. Exposure to 25 °C and 30 °C induced oxidative stress (indicated by elevated levels of lipid peroxidation products) in digestive gland and gills of mussels from A and F sites, while in mussels from N sites elevated oxidative stress was only apparent at 30 °C. Temperature-induced changes in levels of antioxidants (superoxide dismutase, metallothioneins and glutathione) were tissue- and population-specific. Acute warming led to destabilization of lysosomal membranes and increased frequencies of nuclear lesions in mussels from F and A sites but not in their counterparts from N site. Elevated temperature led to an increase in the frequency of micronuclei in hemocytes in mussels from F and A sites at 25 °C and 30 °C and in mussels from N site at 30 °C. The mussels from N site also demonstrated better survival at elevated temperature (30 °C) than their counterparts from the F and A sites. Taken together, these data indicate that long-term acclimation and/or adaptation of A. anatina to elevated temperatures result in increased thermotolerance and alleviate stress response to moderate temperature rise. In contrast, extreme warming (30 °C) is harmful to mussels from all populations indicating limit to this induced

  20. Habitat pollution and thermal regime modify molecular stress responses to elevated temperature in freshwater mussels (Anodonta anatina: Unionidae).

    Science.gov (United States)

    Falfushynska, H; Gnatyshyna, L; Yurchak, I; Ivanina, A; Stoliar, O; Sokolova, I

    2014-12-01

    Elevated temperature and pollution are common stressors in freshwater ecosystems. We study cellular stress response to acute warming in Anodonta anatina (Unionidae) from sites with different thermal regimes and pollution levels: a pristine area and an agriculturally polluted site with normal temperature regimes (F and A, respectively) and a polluted site with elevated temperature (N) from the cooling pond of an electrical power plant. Animals were exposed to different temperatures for 14 days and stress response markers were measured in gills, digestive gland and hemocytes. Mussels from site N and A had elevated background levels of lactate dehydrogenase activity indicating higher reliance on anaerobic metabolism for ATP production and/or redox maintenance. Exposure to 25°C and 30°C induced oxidative stress (indicated by elevated levels of lipid peroxidation products) in digestive gland and gills of mussels from A and F sites, while in mussels from N sites elevated oxidative stress was only apparent at 30°C. Temperature-induced changes in levels of antioxidants (superoxide dismutase, metallothioneins and glutathione) were tissue- and population-specific. Acute warming led to destabilization of lysosomal membranes and increased frequencies of nuclear lesions in mussels from F and A sites but not in their counterparts from N site. Elevated temperature led to an increase in the frequency of micronuclei in hemocytes in mussels from F and A sites at 25°C and 30°C and in mussels from N site at 30°C. The mussels from N site also demonstrated better survival at elevated temperature (30°C) than their counterparts from the F and A sites. Taken together, these data indicate that long-term acclimation and/or adaptation of A. anatina to elevated temperatures result in increased thermotolerance and alleviate stress response to moderate temperature rise. In contrast, extreme warming (30°C) is harmful to mussels from all populations indicating limit to this induced

  1. Experimental research of joint influence of salinization and petroleum pollution on thermal capacity of frozen ground

    Energy Technology Data Exchange (ETDEWEB)

    Motenko, R.G. [Moscow State Univ., Moscow (Russian Federation). Dept. of Geocryology; Grechishcheva, E.S. [Fundamentproek, Moscow (Russian Federation)

    2010-07-01

    Most gas and petroleum fields are located in permafrost zones, with some being on saline territories. Oil pollution of soils can occur in different ways and at different points such as during the extraction, processing and storage, and during transportation of oil and petroleum products. Oil producing pollution and salinization of soil often happen together. In this case, the sources of salts are the formation fluid, commercial waste water, the contents of the granaries and other geochemically active substances used for the extraction and desalting of crude oil. Joint salinization and contamination can also happen during the rupture of oil pipelines in saline areas. Although there is research available on the properties of saline soils and on properties of soils polluted with petroleum, there are no studies that describe changes of ground properties with joint pollution of salt and petroleum. This paper presented a study that examined the joint influence of salinization and petroleum pollution on the thermal characteristics of thawed and frozen grounds, particularly on thermal capacity. The paper outlined the purpose of the research and described the experimental methods. It was concluded that an increase of salinization increases the heat capacity of frozen soil because the amount of unfrozen water increases with increasing salinization. 10 refs., 5 figs.

  2. Experimental research of joint influence of salinization and petroleum pollution on thermal capacity of frozen ground

    International Nuclear Information System (INIS)

    Motenko, R.G.

    2010-01-01

    Most gas and petroleum fields are located in permafrost zones, with some being on saline territories. Oil pollution of soils can occur in different ways and at different points such as during the extraction, processing and storage, and during transportation of oil and petroleum products. Oil producing pollution and salinization of soil often happen together. In this case, the sources of salts are the formation fluid, commercial waste water, the contents of the granaries and other geochemically active substances used for the extraction and desalting of crude oil. Joint salinization and contamination can also happen during the rupture of oil pipelines in saline areas. Although there is research available on the properties of saline soils and on properties of soils polluted with petroleum, there are no studies that describe changes of ground properties with joint pollution of salt and petroleum. This paper presented a study that examined the joint influence of salinization and petroleum pollution on the thermal characteristics of thawed and frozen grounds, particularly on thermal capacity. The paper outlined the purpose of the research and described the experimental methods. It was concluded that an increase of salinization increases the heat capacity of frozen soil because the amount of unfrozen water increases with increasing salinization. 10 refs., 5 figs.

  3. An epidemic model for the interactions between thermal regime of rivers and transmission of Proliferative Kidney Disease in salmonid fish

    Science.gov (United States)

    Carraro, Luca; Bertuzzo, Enrico; Mari, Lorenzo; Gatto, Marino; Strepparava, Nicole; Hartikainen, Hanna; Rinaldo, Andrea

    2015-04-01

    Proliferative kidney disease (PKD) affects salmonid populations in European and North-American rivers. It is caused by the endoparasitic myxozoan Tetracapsuloides bryosalmonae, which exploits freshwater bryozoans (Fredericella sultana) and salmonids as primary and secondary hosts, respectively. Incidence and mortality, which can reach up to 90-100%, are known to be strongly related to water temperature. PKD has been present in brown trout population for a long time but has recently increased rapidly in incidence and severity causing a decline in fish catches in many countries. In addition, environmental changes are feared to cause PKD outbreaks at higher latitude and altitude regions as warmer temperatures promote disease development. This calls for a better comprehension of the interactions between disease dynamics and the thermal regime of rivers, in order to possibly devise strategies for disease management. In this perspective, a spatially explicit model of PKD epidemiology in riverine host metacommunities is proposed. The model aims at summarizing the knowledge on the modes of transmission of the disease and the life-cycle of the parasite, making the connection between temperature and epidemiological parameters explicit. The model accounts for both local population and disease dynamics of bryozoans and fish and hydrodynamic dispersion of the parasite spores and hosts along the river network. The model is time-hybrid, coupling inter-seasonal and intra-seasonal dynamics, the former being described in a continuous time domain, the latter seen as time steps of a discrete time domain. In order to test the model, a case study is conducted in river Wigger (Cantons of Aargau and Lucerne, Switzerland), where data about water temperature, brown trout and bryozoan populations and PKD prevalence are being collected.

  4. Monitoring of active layer thermal regime and depth on CALM-S site, James Ross Island, Eastern Antarctic Peninsula

    Science.gov (United States)

    Hrbáček, Filip; Kňažková, Michaela; Nývlt, Daniel; Láska, Kamil; Mueller, Carsten W.; Ondruch, Jakub

    2017-04-01

    ) and -6.7 °C (2015), while the mean annual ground temperature at 5 cm ranged from -5.6 °C (2013) to -5.3 °C (2014). Thawing season started in mid-November between 17th (2013/14) and 24th (2014/15) and ended at the end of February (22nd in 2014/15) and beginning of March (7th in 2013/14). The maximum active layer thickness determined from 0°C isotherm varied from 86 to 87 cm at profile 1, while it reached only 51 to 65 cm at profile 2. The mean probed active layer depth varied between 66 cm (2013/4) and 78 cm (2014/15). The maximum probed active layer depth increased from 100 cm in 2014 to 113 cm in 2016. High variability of active layer depth across CALM-S site was caused by different ground thermal properties of Holocene marine terrace sand and Cretaceous clayey sandstones. These results differ significantly from another CALM-S sites in Antarctica, where the main factors affecting thawing depth variability were snow cover and topography. These results confirmed previous observation from James Ross Island, where variability of active layer depth was related primarily to different ground properties (texture, moisture, physical characteristic) then local climate or snow cover.

  5. Statistical significant changes in ground thermal conditions of alpine Austria during the last decade

    Science.gov (United States)

    Kellerer-Pirklbauer, Andreas

    2016-04-01

    Longer data series (e.g. >10 a) of ground temperatures in alpine regions are helpful to improve the understanding regarding the effects of present climate change on distribution and thermal characteristics of seasonal frost- and permafrost-affected areas. Beginning in 2004 - and more intensively since 2006 - a permafrost and seasonal frost monitoring network was established in Central and Eastern Austria by the University of Graz. This network consists of c.60 ground temperature (surface and near-surface) monitoring sites which are located at 1922-3002 m a.s.l., at latitude 46°55'-47°22'N and at longitude 12°44'-14°41'E. These data allow conclusions about general ground thermal conditions, potential permafrost occurrence, trend during the observation period, and regional pattern of changes. Calculations and analyses of several different temperature-related parameters were accomplished. At an annual scale a region-wide statistical significant warming during the observation period was revealed by e.g. an increase in mean annual temperature values (mean, maximum) or the significant lowering of the surface frost number (F+). At a seasonal scale no significant trend of any temperature-related parameter was in most cases revealed for spring (MAM) and autumn (SON). Winter (DJF) shows only a weak warming. In contrast, the summer (JJA) season reveals in general a significant warming as confirmed by several different temperature-related parameters such as e.g. mean seasonal temperature, number of thawing degree days, number of freezing degree days, or days without night frost. On a monthly basis August shows the statistically most robust and strongest warming of all months, although regional differences occur. Despite the fact that the general ground temperature warming during the last decade is confirmed by the field data in the study region, complications in trend analyses arise by temperature anomalies (e.g. warm winter 2006/07) or substantial variations in the winter

  6. Computational thermal-fluid dynamics analysis of the laminar flow regime in the meander flow geometry characterizing the heat exchanger used in high temperature superconducting current leads

    International Nuclear Information System (INIS)

    Rizzo, Enrico; Heller, Reinhard; Richard, Laura Savoldi; Zanino, Roberto

    2013-01-01

    Highlights: • The laminar regime in the meander flow geometry has been analysed with a previously validated computational strategy. • Several meander flow geometries as well as flow conditions have been analysed. • A range for the Reynolds number has been defined in which the flow can be considered laminar. • Correlations for the pressure drop and the heat transfer coefficients in the laminar regime have been derived. • A comparison between the computed the experimental pressure drop of the W7-X HTS current lead prototype is presented. -- Abstract: The Karlsruhe Institute of Technology and the Politecnico di Torino have developed and validated a computational thermal-fluid dynamics (CtFD) strategy for the systematic analysis of the thermal-hydraulics inside the meander flow heat exchanger used in high-temperature superconducting current leads for fusion applications. In the recent past, the application of this CtFD technique has shown that some operating conditions occurring in these devices may not reach the turbulent regime region. With that motivation, the CtFD analysis of the helium thermal-fluid dynamics inside different meander flow geometries is extended here to the laminar flow regime. Our first aim is to clarify under which operative conditions the flow regime can be considered laminar and how the pressure drop as well as the heat transfer are related to the geometrical parameters and to the flow conditions. From the results of this analysis, correlations for the pressure drop and for the heat transfer coefficient in the meander flow geometry have been derived, which are applicable with good accuracy to the design of meander flow heat exchangers over a broad range of geometrical parameters

  7. Numerical Simulations of the Natural Thermal Regime and Enhanced Geothermal Systems in the St. Lawrence Lowlands Basin, Quebec, Canad

    Science.gov (United States)

    Nowamooz, A.; Therrien, R.; Molson, J. W. H.; Gosselin, L.; Mathieu-Potvin, F.; Raymond, J.; Malo, M.; Comeau, F. A.; Bedard, K.

    2017-12-01

    An enhanced geothermal system (EGS) consists of injecting water into deep sedimentary or basement rocks, which have been hydraulically stimulated, and withdrawing this water for heat extraction. In this work, the geothermal potential of the St. Lawrence Lowlands Basin (SLLB), Quebec, Canada, is evaluated using numerical heat transport simulations. A 3D conceptual model was first developed based on a detailed geological model of the basin and using realistic ranges of hydrothermal properties of the geological formations. The basin thermal regime under natural conditions was simulated with the HydroGeoSphere model assuming non-isothermal single-phase flow, while the hydrothermal properties of the formations were predicted using the PEST parameter estimation package. The simulated basin temperatures were consistent with the measured bottom-hole temperatures (RMSE = 9%). The calibrated model revealed that the areas in the basin with EGS potential, where temperature exceeds 120 °C, are located at depths ranging from 3.5 to 5.5 km. In the second step of the work, the favorable areas are investigated in detail by conducting simulations in a discrete fracture network similar to the one proposed in the literature for the Rosemanowes geothermal site, UK. Simulations consider 4 main horizontal fractures having each an extent of 1000 m × 180 m, and 10 vertical fractures having each an extent of 1000 m × 45 m. The fracture spacing and aperture are uniform and equal to 15 m and 250 μm, respectively. Simulations showed that a commercial project in the SLLB, with conditions similar to those of the Rosemanowes site, would not feasible. However, sensitivity analyses have demonstrated that it would be possible to extract sufficient heat for a period of at least 20 years from a fractured reservoir in this basin under the following conditions: (1) a flow circulation rate below the desired target value (10 L/s instead of 50 L/s), which would require a flexible power plant; (2) an

  8. Experimental studies on a ground coupled heat pump with solar thermal collectors for space heating

    International Nuclear Information System (INIS)

    Xi, Chen; Hongxing, Yang; Lin, Lu; Jinggang, Wang; Wei, Liu

    2011-01-01

    This paper presents experimental studies on a solar-assisted ground coupled heat pump (SAGCHP) system for space heating. The system was installed at the Hebei Academy of Sciences in Shijiazhuang (lat. N38 o 03', long. E114 o 26'), China. Solar collectors are in series connection with the borehole array through plate heat exchangers. Four operation modes of the system were investigated throughout the coldest period in winter (Dec 5th to Dec 27th). The heat pump performance, borehole temperature distributions and solar colleting characteristics of the SAGCHP system are analyzed and compared when the system worked in continuous or intermittent modes with or without solar-assisted heating. The SAGCHP system is proved to perform space heating with high energy efficiency and satisfactory solar fraction, which is a promising substitute for the conventional heating systems. It is also recommended to use the collected solar thermal energy as an alternative source for the heat pump instead of recharging boreholes for heat storage because of the enormous heat capacity of the earth. -- Highlights: → We study four working modes of a solar-assisted ground coupled heat pump. → The heating performance is in direct relation with the borehole temperature. → Solar-assisted heating elevates borehole temperature and system performance. → The system shows higher efficiency over traditional heating systems in cold areas. → Solar heat is not suggested for high temperature seasonal storage.

  9. Aerothermal Ground Testing of Flexible Thermal Protection Systems for Hypersonic Inflatable Aerodynamic Decelerators

    Science.gov (United States)

    Bruce, Walter E., III; Mesick, Nathaniel J.; Ferlemann, Paul G.; Siemers, Paul M., III; DelCorso, Joseph A.; Hughes, Stephen J.; Tobin, Steven A.; Kardell, Matthew P.

    2012-01-01

    Flexible TPS development involves ground testing and analysis necessary to characterize performance of the FTPS candidates prior to flight testing. This paper provides an overview of the analysis and ground testing efforts performed over the last year at the NASA Langley Research Center and in the Boeing Large-Core Arc Tunnel (LCAT). In the LCAT test series, material layups were subjected to aerothermal loads commensurate with peak re-entry conditions enveloping a range of HIAD mission trajectories. The FTPS layups were tested over a heat flux range from 20 to 50 W/cm with associated surface pressures of 3 to 8 kPa. To support the testing effort a significant redesign of the existing shear (wedge) model holder from previous testing efforts was undertaken to develop a new test technique for supporting and evaluating the FTPS in the high-temperature, arc jet flow. Since the FTPS test samples typically experience a geometry change during testing, computational fluid dynamic (CFD) models of the arc jet flow field and test model were developed to support the testing effort. The CFD results were used to help determine the test conditions experienced by the test samples as the surface geometry changes. This paper includes an overview of the Boeing LCAT facility, the general approach for testing FTPS, CFD analysis methodology and results, model holder design and test methodology, and selected thermal results of several FTPS layups.

  10. Ground surface temperature reconstructions: Using in situ estimates for thermal conductivity acquired with a fiber-optic distributed thermal perturbation sensor

    Energy Technology Data Exchange (ETDEWEB)

    Freifeld, B.M.; Finsterle, S.; Onstott, T.C.; Toole, P.; Pratt, L.M.

    2008-10-10

    We have developed a borehole methodology to estimate formation thermal conductivity in situ with a spatial resolution of one meter. In parallel with a fiber-optic distributed temperature sensor (DTS), a resistance heater is deployed to create a controlled thermal perturbation. The transient thermal data is inverted to estimate the formation's thermal conductivity. We refer to this instrumentation as a Distributed Thermal Perturbation Sensor (DTPS), given the distributed nature of the DTS measurement technology. The DTPS was deployed in permafrost at the High Lake Project Site (67 degrees 22 minutes N, 110 degrees 50 minutes W), Nunavut, Canada. Based on DTPS data, a thermal conductivity profile was estimated along the length of a wellbore. Using the thermal conductivity profile, the baseline geothermal profile was then inverted to estimate a ground surface temperature history (GSTH) for the High Lake region. The GSTH exhibits a 100-year long warming trend, with a present-day ground surface temperature increase of 3.0 {+-} 0.8 C over the long-term average.

  11. Advanced Coupled Simulation of Borehole Thermal Energy Storage Systems and Above Ground Installations

    Science.gov (United States)

    Welsch, Bastian; Rühaak, Wolfram; Schulte, Daniel O.; Bär, Kristian; Sass, Ingo

    2016-04-01

    Seasonal thermal energy storage in borehole heat exchanger arrays is a promising technology to reduce primary energy consumption and carbon dioxide emissions. These systems usually consist of several subsystems like the heat source (e.g. solarthermics or a combined heat and power plant), the heat consumer (e.g. a heating system), diurnal storages (i.e. water tanks), the borehole thermal energy storage, additional heat sources for peak load coverage (e.g. a heat pump or a gas boiler) and the distribution network. For the design of an integrated system, numerical simulations of all subsystems are imperative. A separate simulation of the borehole energy storage is well-established but represents a simplification. In reality, the subsystems interact with each other. The fluid temperatures of the heat generation system, the heating system and the underground storage are interdependent and affect the performance of each subsystem. To take into account these interdependencies, we coupled a software for the simulation of the above ground facilities with a finite element software for the modeling of the heat flow in the subsurface and the borehole heat exchangers. This allows for a more realistic view on the entire system. Consequently, a finer adjustment of the system components and a more precise prognosis of the system's performance can be ensured.

  12. Solvo-thermal in situ transesterification of wet spent coffee grounds for the production of biodiesel.

    Science.gov (United States)

    Park, Jeongseok; Kim, Bora; Son, Jeesung; Lee, Jae W

    2018-02-01

    This work addresses non-catalytic biodiesel production from spent coffee ground (SCG) by integrating solvo-thermal effect of 1,2-dichloroethane (DCE) with in situ transesterification over 160 °C. The SCG water content has a positive effect on the DCE hydrolysis up to 60 wt% due to the bimolecular substitution mechanism. The hydrolysis gives an acidic environment favorable for cellulose decomposition, SCG particle size reduction and lipid conversion. The optimal fatty acid ethyl ester yield was 11.8 wt% based on the mass of dried SCG with 3.36 ml ethanol and 3.16 ml DCE at 196.8 °C through the response surface methodology. Using the solvo-thermal effect, direct utilization of wet SCG as a biodiesel feedstock provides not only economic feasibility without using drying process and additional acid catalyst but also environmental advantage of recycling the municipal waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Characterizing Effects and Benefits of Beam Defocus on High Energy Laser Performance Under Thermal Blooming and Turbulence Conditions for Air-to-Ground Engagements

    National Research Council Canada - National Science Library

    Long, Scott N

    2008-01-01

    ...) regime in thermal blooming conditions. Wave optics modeling techniques were used to represent laser weapon performance in a high fidelity sense to allow progress to be made toward improving lower-fidelity scaling laws that can be...

  14. Time-saving method of orbital thermal regime calculations of nanosatellites as exemplified by a 3U CubeSat

    Directory of Open Access Journals (Sweden)

    Gorev Vasily

    2018-01-01

    Full Text Available A time-saving approach to perform technical calculations of thermal conditions of orbital motion of 3U CubeSat nanosatellite was applied, which made it possible to make the thermal calculations of a satellite with simple structure geometry using MatLab and SolidWorks Simulation. Passive thermal regulation facilities are sufficient for a 3U CubeSat to provide thermal conductivity of the case’s structural elements and to remove heat from the lighted surface and internal components to the satellite’s shadowed surface. Application of spectrally selective coatings allows narrowing the range of surface temperatures of 3U CubeSat.

  15. Evaluating the performance of coupled snow-soil models in SURFEXv8 to simulate the permafrost thermal regime at a high Arctic site

    Science.gov (United States)

    Barrere, Mathieu; Domine, Florent; Decharme, Bertrand; Morin, Samuel; Vionnet, Vincent; Lafaysse, Matthieu

    2017-09-01

    Climate change projections still suffer from a limited representation of the permafrost-carbon feedback. Predicting the response of permafrost temperature to climate change requires accurate simulations of Arctic snow and soil properties. This study assesses the capacity of the coupled land surface and snow models ISBA-Crocus and ISBA-ES to simulate snow and soil properties at Bylot Island, a high Arctic site. Field measurements complemented with ERA-Interim reanalyses were used to drive the models and to evaluate simulation outputs. Snow height, density, temperature, thermal conductivity and thermal insulance are examined to determine the critical variables involved in the soil and snow thermal regime. Simulated soil properties are compared to measurements of thermal conductivity, temperature and water content. The simulated snow density profiles are unrealistic, which is most likely caused by the lack of representation in snow models of the upward water vapor fluxes generated by the strong temperature gradients within the snowpack. The resulting vertical profiles of thermal conductivity are inverted compared to observations, with high simulated values at the bottom of the snowpack. Still, ISBA-Crocus manages to successfully simulate the soil temperature in winter. Results are satisfactory in summer, but the temperature of the top soil could be better reproduced by adequately representing surface organic layers, i.e., mosses and litter, and in particular their water retention capacity. Transition periods (soil freezing and thawing) are the least well reproduced because the high basal snow thermal conductivity induces an excessively rapid heat transfer between the soil and the snow in simulations. Hence, global climate models should carefully consider Arctic snow thermal properties, and especially the thermal conductivity of the basal snow layer, to perform accurate predictions of the permafrost evolution under climate change.

  16. Ground truth measurements plan for the Multispectral Thermal Imager (MTI) satellite

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, A.J.

    2000-01-03

    Sandia National Laboratories (SNL), Los Alamos National Laboratory (LANL), and the Savannah River Technology Center (SRTC) have developed a diverse group of algorithms for processing and analyzing the data that will be collected by the Multispectral Thermal Imager (MTI) after launch late in 1999. Each of these algorithms must be verified by comparison to independent surface and atmospheric measurements. SRTC has selected 13 sites in the continental U.S. for ground truth data collections. These sites include a high altitude cold water target (Crater Lake), cooling lakes and towers in the warm, humid southeastern US, Department of Energy (DOE) climate research sites, the NASA Stennis satellite Validation and Verification (V and V) target array, waste sites at the Savannah River Site, mining sites in the Four Corners area and dry lake beds in the southwestern US. SRTC has established mutually beneficial relationships with the organizations that manage these sites to make use of their operating and research data and to install additional instrumentation needed for MTI algorithm V and V.

  17. Ground Testing a Nuclear Thermal Rocket: Design of a sub-scale demonstration experiment

    Energy Technology Data Exchange (ETDEWEB)

    David Bedsun; Debra Lee; Margaret Townsend; Clay A. Cooper; Jennifer Chapman; Ronald Samborsky; Mel Bulman; Daniel Brasuell; Stanley K. Borowski

    2012-07-01

    In 2008, the NASA Mars Architecture Team found that the Nuclear Thermal Rocket (NTR) was the preferred propulsion system out of all the combinations of chemical propulsion, solar electric, nuclear electric, aerobrake, and NTR studied. Recently, the National Research Council committee reviewing the NASA Technology Roadmaps recommended the NTR as one of the top 16 technologies that should be pursued by NASA. One of the main issues with developing a NTR for future missions is the ability to economically test the full system on the ground. In the late 1990s, the Sub-surface Active Filtering of Exhaust (SAFE) concept was first proposed by Howe as a method to test NTRs at full power and full duration. The concept relied on firing the NTR into one of the test holes at the Nevada Test Site which had been constructed to test nuclear weapons. In 2011, the cost of testing a NTR and the cost of performing a proof of concept experiment were evaluated.

  18. Ground-based infrared surveys: imaging the thermal fields at volcanoes and revealing the controlling parameters.

    Science.gov (United States)

    Pantaleo, Michele; Walter, Thomas

    2013-04-01

    Temperature monitoring is a widespread procedure in the frame of volcano hazard monitoring. Indeed temperature changes are expected to reflect changes in volcanic activity. We propose a new approach, within the thermal monitoring, which is meant to shed light on the parameters controlling the fluid pathways and the fumarole sites by using infrared measurements. Ground-based infrared cameras allow one to remotely image the spatial distribution, geometric pattern and amplitude of fumarole fields on volcanoes at metre to centimetre resolution. Infrared mosaics and time series are generated and interpreted, by integrating geological field observations and modeling, to define the setting of the volcanic degassing system at shallow level. We present results for different volcano morphologies and show that lithology, structures and topography control the appearance of fumarole field by the creation of permeability contrasts. We also show that the relative importance of those parameters is site-dependent. Deciphering the setting of the degassing system is essential for hazard assessment studies because it would improve our understanding on how the system responds to endogenous or exogenous modification.

  19. Review of biomaterial thermal property measurements in the cryogenic regime and their use for prediction of equilibrium and non-equilibrium freezing applications in cryobiology.

    Science.gov (United States)

    Choi, Jeunghwan; Bischof, John C

    2010-02-01

    It is well accepted in cryobiology that the temperature history and cooling rates experienced in biomaterials during freezing procedures correlate strongly with biological outcome. Therefore, heat transfer measurement and prediction in the cryogenic regime is central to the field. Although direct measurement of temperature history (i.e. heat transfer) can be performed, accuracy is usually achieved only for local measurements within a given system and cannot be readily generalized to another system without the aid of predictive models. The accuracy of these models rely upon thermal properties which are known to be highly dependent on temperature, and in the case of significant cryoprotectant loading, also on crystallized fraction. In this work, we review the available thermal properties of biomaterials in the cryogenic regime. The review shows a lack of properties for many biomaterials in the subzero temperature domain, and especially for systems with cryoprotective agents. Unfortunately, use of values from the limited data available (usually only down to -40 degrees C) lead to an underestimation of thermal property change (i.e. conductivity rise and specific heat drop due to ice crystallization) with lower temperatures. Conversely, use of surrogate values based solely on ice thermal properties lead to an overestimation of thermal property change for most biomaterials. Additionally, recent work extending the range of available thermal properties to -150 degrees C has shown that the thermal conductivity will drop in both PBS and tissue (liver) due to amorphous/glassy phases (versus crystalline) of biomaterials with the addition of cryoprotective additives such as glycerol. Thus, we investigated the implications of using approximated or constant property values versus measured temperature-dependent values for predicting temperature history during freezing in PBS (phosphate-buffered saline) and porcine liver with and without cryoprotectants (glycerol). Using measured

  20. Constraining aerosol optical models using ground-based, collocated particle size and mass measurements in variable air mass regimes during the 7-SEAS/Dongsha experiment

    Science.gov (United States)

    Bell, Shaun W.; Hansell, Richard A.; Chow, Judith C.; Tsay, Si-Chee; Hsu, N. Christina; Lin, Neng-Huei; Wang, Sheng-Hsiang; Ji, Qiang; Li, Can; Watson, John G.; Khlystov, Andrey

    2013-10-01

    During the spring of 2010, NASA Goddard's COMMIT ground-based mobile laboratory was stationed on Dongsha Island off the southwest coast of Taiwan, in preparation for the upcoming 2012 7-SEAS field campaign. The measurement period offered a unique opportunity for conducting detailed investigations of the optical properties of aerosols associated with different air mass regimes including background maritime and those contaminated by anthropogenic air pollution and mineral dust. What appears to be the first time for this region, a shortwave optical closure experiment (λ = 550 nm) for both scattering and absorption was attempted over a 12-day period during which aerosols exhibited the most change. Constraints to the optical model included combined SMPS and APS number concentration data for a continuum of fine and coarse-mode particle sizes up to PM2.5. We also take advantage of an IMPROVE chemical sampler to help constrain aerosol composition and mass partitioning of key elemental species including sea-salt, particulate organic matter, soil, non sea-salt sulfate, nitrate, and elemental carbon. Achieving full optical closure is hampered by limitations in accounting for the role of water vapor in the system, uncertainties in the instruments and the need for further knowledge in the source apportionment of the model's major chemical components. Nonetheless, our results demonstrate that the observed aerosol scattering and absorption for these diverse air masses are reasonably captured by the model, where peak aerosol events and transitions between key aerosols types are evident. Signatures of heavy polluted aerosol composed mostly of ammonium and non sea-salt sulfate mixed with some dust with transitions to background sea-salt conditions are apparent in the absorption data, which is particularly reassuring owing to the large variability in the imaginary component of the refractive indices. Consistency between the measured and modeled optical parameters serves as an

  1. Constraining Aerosol Optical Models Using Ground-Based, Collocated Particle Size and Mass Measurements in Variable Air Mass Regimes During the 7-SEAS/Dongsha Experiment

    Science.gov (United States)

    Bell, Shaun W.; Hansell, Richard A.; Chow, Judith C.; Tsay, Si-Chee; Wang, Sheng-Hsiang; Ji, Qiang; Li, Can; Watson, John G.; Khlystov, Andrey

    2012-01-01

    During the spring of 2010, NASA Goddard's COMMIT ground-based mobile laboratory was stationed on Dongsha Island off the southwest coast of Taiwan, in preparation for the upcoming 2012 7-SEAS field campaign. The measurement period offered a unique opportunity for conducting detailed investigations of the optical properties of aerosols associated with different air mass regimes including background maritime and those contaminated by anthropogenic air pollution and mineral dust. What appears to be the first time for this region, a shortwave optical closure experiment for both scattering and absorption was attempted over a 12-day period during which aerosols exhibited the most change. Constraints to the optical model included combined SMPS and APS number concentration data for a continuum of fine and coarse-mode particle sizes up to PM2.5. We also take advantage of an IMPROVE chemical sampler to help constrain aerosol composition and mass partitioning of key elemental species including sea-salt, particulate organic matter, soil, non sea-salt sulphate, nitrate, and elemental carbon. Our results demonstrate that the observed aerosol scattering and absorption for these diverse air masses are reasonably captured by the model, where peak aerosol events and transitions between key aerosols types are evident. Signatures of heavy polluted aerosol composed mostly of ammonium and non sea-salt sulphate mixed with some dust with transitions to background sea-salt conditions are apparent in the absorption data, which is particularly reassuring owing to the large variability in the imaginary component of the refractive indices. Extinctive features at significantly smaller time scales than the one-day sample period of IMPROVE are more difficult to reproduce, as this requires further knowledge concerning the source apportionment of major chemical components in the model. Consistency between the measured and modeled optical parameters serves as an important link for advancing remote

  2. Performance and costs of a roof-sized PV/thermal array combined with a ground coupled heat pump

    International Nuclear Information System (INIS)

    Bakker, M.; Zondag, H.A.; Elswijk, M.J.; Strootman, K.J.; Jong, M.J.M.

    2005-01-01

    A photovoltaic/thermal (PVT) panel is a combination of photovoltaic cells with a solar thermal collector, generating solar electricity and solar heat simultaneously. Hence, PVT panels are an alternative for a combination of separate PV panels and solar thermal collectors. A promising system concept, consisting of 25 m 2 of PVT panels and a ground coupled heat pump, has been simulated in TRNSYS. It has been found that this system is able to cover 100% of the total heat demand for a typical newly-built Dutch one-family dwelling, while covering nearly all of its own electricity use and keeping the long-term average ground temperature constant. The cost of such a system has been compared to the cost of a reference system, where the PVT panels have been replaced with separate PV panels (26 m 2 ) and solar thermal collectors (7 m 2 ), but which is otherwise identical. The electrical and thermal yield of this reference system is equal to that of the PVT system. It has been found that both systems require a nearly identical initial investment. Finally, a view on future PVT markets is given. In general, the residential market is by far the most promising market. The system discussed in this paper is expected to be most successful in newly-built low-energy housing concepts. (Author)

  3. Performance and costs of a roof-sized PV/thermal array combined with a ground coupled heat pump

    International Nuclear Information System (INIS)

    Bakker, M.; Zondag, H.A.; Elswijk, M.J.; Strootman, K.J.; Jong, M.J.M.

    2005-03-01

    A photovoltaic/thermal (PVT) panel is a combination of photovoltaic cells with a solar thermal collector, generating solar electricity and solar heat simultaneously. Hence, PVT panels are an alternative for a combination of separate PV panels and solar thermal collectors. A promising system concept, consisting of 25 m 2 of PVT panels and a ground coupled heat pump, has been simulated in TRNSYS. It has been found that this system is able to cover 100% of the total heat demand for a typical newly-built Dutch one-family dwelling, while covering nearly all of its own electricity use and keeping the long-term average ground temperature constant. The cost of such a system has been compared to the cost of a reference system, where the PVT panels have been replaced with separate PV panels (26 m 2 ) and solar thermal collectors (7 m 2 ), but which is otherwise identical. The electrical and thermal yield of this reference system is equal to that of the PVT system. It has been found that both systems require a nearly identical initial investment. Finally, a view on future PVT markets is given. In general, the residential market is by far the most promising market. The system discussed in this paper is expected to be most successful in newly-built low-energy housing concepts

  4. Thermal Emission from Transiting Very-Hot Jupiters: Prospects for Ground-based Detection at Optical Wavelengths

    OpenAIRE

    Lopez-Morales, Mercedes; Seager, Sara

    2007-01-01

    Very hot Jupiters (VHJs) are defined as Jupiter-mass extrasolar planets with orbital periods shorter than three days. For low albedos the effective temperatures of irradiated VHJs can reach 2500-3000 K. Thermal emission from VHJs is therefore potentially strong at optical wavelengths. We explore the prospects of detecting optical-wavelength thermal emission during secondary eclipse with existing ground-based telescopes. We show that OGLE-TR-56b and OGLE-TR-132b are the best suited candidates ...

  5. Microwave complex for ground based ozone and thermal sounding of middle atmosphere

    Science.gov (United States)

    Shvetsov, Alexander; Krasil'nikov, Alexander; Kulikov, Mihail; Ryskin, Vitaly; Bolshakov, Oleg; Belikovich, Mihail; Mukhin, Dmitry; Karashtin, Dmitry; Fedoseev, Lev; Feigin, Alexander

    2013-04-01

    Description of the novel ground-based microwave complex for ozone and thermal sounding of middle atmosphere is presented. The instrument include two spectroradiometers operating in the frequency range 110.3-111.3 GHz (ozone line), and in the in the frequency range 52.5 - 54.5 GHz (edge of 5-mm molecular oxygen band), accordingly. The latter includes band slope and four resolved from the earth's surface relatively weak oxygen lines. Both spectroradiometers employ feed cone as antenna with half-power beam width approximately equal 4 degree. Two digital fast Fourier transform spectrometers developed by "Acqiris" are used for signal analysis in the intermediate frequency range 0.05 - 1 GHz with the effective resolution 61 KHz. Both spectroradiometers operate in total power mod with fast internal calibration that realize by electrically controlled noise generator on basis of Shottky barrier diodes. Noise temperature is approximately 3000 K for ozone spectroradiometer and 1400 K for thermometer. Novel method for retrieval vertical profiles of ozone and temperature from radiometric data is applied. The procedure is based on Bayesian approach to inverse problems which assumes a construction of probability distribution of the characteristics of retrieved profiles with taking into account measurement noise and available a priori information about possible distributions of ozone and temperature in the middle atmosphere. At the present time we carry out the experimental campaign aimed to simultaneous measurements temperature and ozone profile above Nizhny Novgorod, Russia. The work was done under support of the RFBR (projects 11-05-97050 and 12-05-00999)

  6. Detecting the Benefits of Shade Management in the Thermal Regime of an Upland River Under Positive and Negative Phases of the NAO

    Science.gov (United States)

    Wilby, R.; Johnson, M. F.

    2017-12-01

    Water temperature is an important determinant of river ecosystem function and health. Hence, there is growing concern about rising surface water temperatures as a consequence of global warming and human modifications to river regimes. Some agencies are advocating riparian shade management as a means of `keeping rivers cool'. As appealing as this policy might seem, there are a host of practical considerations such as which species to plant, where to plant, and how much to plant? Moreover, there can be unintended consequences for groundwater recharge, flood risk and nutrient fluxes through the buffer zone. The thermal benefits of tree-planting may also be hard to detect amidst the integrated, downstream effects of landscape shade and flows from springs. Yet, to truly evaluate shade management as an adaptation to climate change, clear evidence is needed of the costs and benefits of this local intervention. What has this got to do with natural modes of climate variability? Continental scale, hydrological impacts of ENSO, the PDO and NAO have been widely reported - these periodic variations in ocean-atmosphere circulations are often blamed for floods, droughts, wildfire, crop failures, and the like. But there is emerging evidence that such phenomena also drive inter-annual variations in the heat flux of rivers. This matters because the underlying signal can confound field and model experiments intended to test adaptation options. Here, we present evidence of NAO signatures in the water temperature regime of the River Dove, UK. We compare the amplitude of these thermal variations with the expected benefit of tree planting. We demonstrate that the difference in maximum summer water temperature between strongly positive and strongly negative NAO phases can be about 2.5°C. This is equivalent to the thermal benefit of more than 2 km of riparian shade for the river studied. So, whilst modes of climate variability undoubtedly have a global footprint, let us not forget that

  7. Impacts of projected mid-century temperatures on thermal regimes for select specialty and fieldcrops common to the southwestern U.S.

    Science.gov (United States)

    Elias, E.; Lopez-Brody, N.; Dialesandro, J.; Steele, C. M.; Rango, A.

    2015-12-01

    The impacts of projected temperature increases in agricultural ecosystems are complex, varyingby region, cropping system, crop growth stage and humidity. We analyze the impacts of mid-century temperature increases on crops grown in five southwestern states: Arizona, California,New Mexico, Nevada and Utah. Here we present a spatial impact assessment of commonsouthwestern specialty (grapes, almonds and tomatoes) and field (alfalfa, cotton and corn)crops. This analysis includes three main components: development of empirical temperaturethresholds for each crop, classification of predicted future climate conditions according to thesethresholds, and mapping the probable impacts of these climatic changes on each crop. We use30m spatial resolution 2012 crop distribution and seasonal minimum and maximumtemperature normals (1970 to 2000) to define the current thermal envelopes for each crop.These represent the temperature range for each season where 95% of each crop is presentlygrown. Seasonal period change analysis of mid-century temperatures changes downscaled from20 CMIP5 models (RCP8.5) estimate future temperatures. Change detection maps representareas predicted to become more or less suitable, or remain unchanged. Based upon mid-centurytemperature changes, total regional suitable area declined for all crops except cotton, whichincreased by 20%. For each crop there are locations which change to and from optimal thermalenvelope conditions. More than 80% of the acres currently growing tomatoes and almonds willshift outside the present 95% thermal range. Fewer acres currently growing alfalfa (14%) andcotton (20%) will shift outside the present 95% thermal range by midcentury. Crops outsidepresent thermal envelopes by midcentury may adapt, possibly aided by adaptation technologiessuch as misters or shade structures, to the new temperature regime or growers may elect togrow alternate crops better suited to future thermal envelopes.

  8. ENSURING THERMAL REGIME FOR THE SUPPLY DISTRIBUTED DEVICES IN THE COMPOSITION OF THE SHIP'S SECONDARY POWER SUPPLY SYSTEMS ON THE BASE OF THE STANDARDIZED UNITS

    Directory of Open Access Journals (Sweden)

    T. A. Ismailov

    2016-01-01

    Full Text Available Aim. The article deals with the problem of constructing the power supply devices in the composition of the ship's secondary power systems based on standardized blocks and securing their thermal regime.Methods. It is stated that with the advent of modern power electronics multifunctional components the secondary power supply developers got possibilities to improve the quality of secondary power supply and to upgrade the existing systems.Results. The advantages of unified power units, having a function of parallel operation are revealed. Heat transfer processes in a vertical channel with free convection, and the calculation of the minimum width of the channel, which provides efficient heat removal have been analyzed.Conclusion.A model is proposed for determining the minimum distance between the blocks without deterioration of heat transfer in the channel formed by the walls of adjacent blocks.

  9. Impact of climate change on soil thermal and moisture regimes in Serbia: An analysis with data from regional climate simulations under SRES-A1B.

    Science.gov (United States)

    Mihailović, D T; Drešković, N; Arsenić, I; Ćirić, V; Djurdjević, V; Mimić, G; Pap, I; Balaž, I

    2016-11-15

    We considered temporal and spatial variations to the thermal and moisture regimes of the most common RSGs (Reference Soil Groups) in Serbia under the A1B scenario for the 2021-2050 and 2071-2100 periods, with respect to the 1961-1990 period. We utilized dynamically downscaled global climate simulations from the ECHAM5 model using the coupled regional climate model EBU-POM (Eta Belgrade University-Princeton Ocean Model). We analysed the soil temperature and moisture time series using simple statistics and a Kolmogorov complexity (KC) analysis. The corresponding metrics were calculated for 150 sites. In the future, warmer and drier regimes can be expected for all RSGs in Serbia. The calculated soil temperature and moisture variations include increases in the mean annual soil temperature (up to 3.8°C) and decreases in the mean annual soil moisture (up to 11.3%). Based on the KC values, the soils in Serbia are classified with respect to climate change impacts as (1) less sensitive (Vertisols, Umbrisols and Dystric Cambisols) or (2) more sensitive (Chernozems, Eutric Cambisols and Planosols). Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Thermal regime at the Upper Stillwater dam site, Uinta mountains, Utah: Implications for terrain, microclimate and structural corrections in heat flow studies

    Science.gov (United States)

    Bauer, Michael S.; Chapman, David S.

    1986-08-01

    A detailed study of the subsurface thermal regime at the Upper Stillwater dam site, Uinta Mountains, northeast Utah, has been made. Temperature measurements were made in 36 drillholes located within a 1 km 2 area and ranging in depth from 20 to 97 m. Holes less than about 40 m deep were used only to obtain information about spatial variations in mean annual surface temperature. Several holes in or near talus slopes at the sides of the canyons have temperature minima approaching 0°C between 10 and 20 m indicating the presence of year-round ice at the base of the talus. Another set of holes show transient thermal effects of surface warming resulting from clearing of a construction site 3.5 years prior to our measurements. Most of the remaining holes show conductive behavior and have gradients ranging from 13° to 17°C km -1. Measurements made on 44 core samples yield a thermal conductivity of 5.6 (std. dev. 0.35) W m -1 K -1 for the Precambrian quartzite present. Surface heat flow estimates for these holes range from 70 to 100 mW m -2. However, the local disturbance of the thermal field by topography and microclimate is considerable. A finite difference method used to model these effects yielded a locally corrected Upper Stillwater heat flow of about 75 mW m -2. A final correction to account for the effects of refraction of heat from the low conductivity sedimentary rocks in the Uinta Basin into the high conductivity quartzite at the dam site, produced a regionally corrected Upper Stillwater heat flow between 60 and 65 mW m -2. This value is consistent with the observed heat flow of 60 mW m -2 in the Green River Basin to the north and the Uinta Basin to the south.

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

    Science.gov (United States)

    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.

  12. The stretching amplitude and thermal regime of the lithosphere in the nonvolcanic passive margin of Antarctica in the Mawson Sea region

    Science.gov (United States)

    Galushkin, Yu. I.; Leitchenkov, G. L.; Guseva, Yu. B.; Dubinin, E. P.

    2018-01-01

    The burial history and thermal evolution of the lithosphere within the passive nonvolcanic Antarctic margin in the region of the Mawson Sea are numerically reconstructed for the margin areas along the seismic profile 5909 with the use of the GALO basin modeling system. The amplitudes of the lithosphere stretching at the different stages of continental rifting which took place from 160 to 90 Ma ago are calculated from the geophysical estimates of the thickness of the consolidated crust and the tectonic analysis of the variations in the thickness of the sedimentary cover and sea depths during the evolution of the basin. It is hypothesized that the formation of the recent sedimentary section sequence in the studied region of the Antarctic margin began 140 Ma ago on a basement that was thinned by a factor of 1.6 to 4.5 during the first episode of margin stretching (160-140 Ma) under a fairly high heat flux. The reconstruction of the thermal regime of the lithosphere has shown that the mantle rocks could occur within the temperature interval of serpentinization and simultaneously within the time interval of lithospheric stretching (-160 fractures in these zones is less probable. However, serpentinization could take place in these areas as in the other margin segments at the stage of presedimentation ultra slow basement stretching.

  13. The thermal regime in the resurgent dome of Long Valley Caldera, California: Inferences from precision temperature logs in deep wells

    Science.gov (United States)

    Hurwitz, S.; Farrar, C.D.; Williams, C.F.

    2010-01-01

    Long Valley Caldera in eastern California formed 0.76Ma ago in a cataclysmic eruption that resulted in the deposition of 600km3 of Bishop Tuff. The total current heat flow from the caldera floor is estimated to be ~290MW, and a geothermal power plant in Casa Diablo on the flanks of the resurgent dome (RD) generates ~40MWe. The RD in the center of the caldera was uplifted by ~80cm between 1980 and 1999 and was explained by most models as a response to magma intrusion into the shallow crust. This unrest has led to extensive research on geothermal resources and volcanic hazards in the caldera. Here we present results from precise, high-resolution, temperature-depth profiles in five deep boreholes (327-1,158m) on the RD to assess its thermal state, and more specifically 1) to provide bounds on the advective heat transport as a guide for future geothermal exploration, 2) to provide constraints on the occurrence of magma at shallow crustal depths, and 3) to provide a baseline for future transient thermal phenomena in response to large earthquakes, volcanic activity, or geothermal production. The temperature profiles display substantial non-linearity within each profile and variability between the different profiles. All profiles display significant temperature reversals with depth and temperature gradients temperature in the individual boreholes ranges between 124.7??C and 129.5??C and bottom hole temperatures range between 99.4??C and 129.5??C. The high-temperature units in the three Fumarole Valley boreholes are at the approximate same elevation as the high-temperature unit in borehole M-1 in Casa Diablo indicating lateral or sub-lateral hydrothermal flow through the resurgent dome. Small differences in temperature between measurements in consecutive years in three of the wells suggest slow cooling of the shallow hydrothermal flow system. By matching theoretical curves to segments of the measured temperature profiles, we calculate horizontal groundwater velocities in

  14. Fabrication and Testing of Nuclear-Thermal Propulsion Ground Test Hardware, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Efficient nuclear-thermal propulsion requires heating a low molecular weight gas, typically hydrogen, to high temperature and expelling it through a nozzle. The...

  15. Fabrication and Testing of Nuclear-Thermal Propulsion Ground Test Hardware, Phase II, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Efficient nuclear-thermal propulsion (NTP) requires heating a low molecular weight gas, typically hydrogen, to high temperature and expelling it through a nozzle....

  16. Fabrication and Testing of Nuclear-Thermal Propulsion Ground Test Hardware Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Efficient nuclear-thermal propulsion requires heating a low molecular weight gas, typically hydrogen, to high temperature and expelling it through a nozzle. The...

  17. Ion thermal conductivity and convective energy transport in JET hot-ion regimes and H-modes

    International Nuclear Information System (INIS)

    Tibone, F.; Balet, B.; Cordey, J.G.

    1989-01-01

    Local transport in a recent series of JET experiments has been studied using interpretive codes. Auxiliary heating, mainly via neutral beam injection, was applied on low-density target plasmas confined in the double-null X-point configuration. This has produced two-component plasmas with high ion temperature and neutron yield and, above a threshold density, H-modes characterised by peak density and power deposition profiles. H-mode confinement was also obtained for the first time with 25 MW auxiliary power, of which 10 MW was from ion cyclotron resonance heating. We have used profile measurements of electron temperature T e from electron cyclotron emission and LIDAR Thomson scattering, ion temperature T i from charge-exchange recombination spectroscopy (during NBI), electron density n e from LIDAR and Abel-inverted interferometer measurements. Only sparse information is, however, available to date concerning radial profiles of effective ionic charge and radiation losses. Deuterium depletion due to high impurity levels is an important effect in these discharges, and our interpretation of thermal ion energy content, neutron yield and ion particle fluxes needs to be confirmed using measured Z eff -profiles. (author) 4 refs., 4 figs

  18. Random walks with thermalizing collisions in bounded regions: Physical applications valid from the ballistic to diffusive regimes

    Science.gov (United States)

    Swank, C. M.; Petukhov, A. K.; Golub, R.

    2016-06-01

    The behavior of a spin undergoing Larmor precession in the presence of fluctuating fields is of interest to workers in many fields. The fluctuating fields cause frequency shifts and relaxation which are related to their power spectrum, which can be determined by taking the Fourier transform of the auto-correlation functions of the field fluctuations. Recently we have shown how to calculate these correlation functions for all values of mean-free path (ballistic to diffusive motion) in finite bounded regions by using the model of persistent continuous time random walks (CTRW) for particles subject to scattering by fixed (frozen) scattering centers so that the speed of the moving particles is not changed by the collisions. In this work we show how scattering with energy exchange from an ensemble of scatterers in thermal equilibrium can be incorporated into the CTRW. We present results for 1, 2, and 3 dimensions. The results agree for all these cases contrary to the previously studied "frozen" models. Our results for the velocity autocorrelation function show a long-time tail (˜t-1 /2 ), which we also obtain from conventional diffusion theory, with the same power, independent of dimensionality. Our results are valid for any Markovian scattering kernel as well as for any kernel based on a scattering cross section ˜1 /v .

  19. The effect of production regime and crucible materials on the thermal properties of sodium phosphate glasses produced from salts.

    Science.gov (United States)

    Parsons, A J; Burling, L D; Rudd, C D; Scotchford, C A; Walker, G S

    2004-10-15

    Changes in the thermal properties of sodium phosphate glasses during melt production have been investigated using Pt/Au and fused alumina crucibles. Glasses were produced from NaH(2)PO(4) as a starting material, providing an intrinsic Na(2)O:P(2)O(5) ratio of 1:1 and giving an O/P = 3, that is, a metaphosphate. In Pt/Au crucibles, glass transition temperatures rose to a plateau value of 295 degrees C at a rate determined by melt temperature. No contamination of the glass by platinum or gold was detected or indicated in the results. E(a) for the reaction was found to be 66.4 kJ mol(-1). In fused alumina crucibles, glass transition temperatures rose to over 450 degrees C, with these values showing some convergence at higher furnace temperatures. Extensive erosion of the alumina crucibles was observed. The amount of alumina incorporation within the glasses correlated well with the rise in glass transition temperature up to a maximum of 15.5 mol % Al(2)O(3) content. Al(2)O(3) incorporation above this value caused a reduction in the value of the T(g).

  20. Field mapping for heat capacity mapping determinations: Ground support for airborne thermal surveys

    Science.gov (United States)

    Lyon, R. J. P.

    1976-01-01

    Thermal models independently derived by Watson, Outcalt, and Rosema were compared using similar input data and found to yield very different results. Each model has a varying degree of sensitivity to any specified parameter. Data collected at Pisgah Crater-Lavic Lake was re-examined to indicate serious discrepancy in results for thermal inertia from Jet Lab Propulsion Laboratory calculations, when made using the same orginal data sets.

  1. Characterization of Jupiter's Atmosphere from Observation of Thermal Emission by Juno and Ground-Based Supporting Observations

    Science.gov (United States)

    Orton, G. S.; Momary, T.; Tabataba-Vakili, F.; Janssen, M. A.; Hansen, C. J.; Bolton, S. J.; Li, C.; Adriani, A.; Mura, A.; Grassi, D.; Fletcher, L. N.; Brown, S. T.; Fujiyoshi, T.; Greathouse, T. K.; Kasaba, Y.; Sato, T. M.; Stephens, A.; Donnelly, P.; Eichstädt, G.; Rogers, J.

    2017-12-01

    Ground-breaking measurements of thermal emission at very long wavelengths have been made by the Juno mission's Microwave Radiometer (MWR). We examine the relationship between these and other thermal emission measurements by the Jupiter Infrared Auroral Mapper (JIRAM) at 5 µm and ground-based supporting observations in the thermal infrared that cover the 5-25 µm range. The relevant ground-based observations of thermal emission are constituted from imaging and scanning spectroscopy obtained at the NASA Infrared Telescope Facility (IRTF), the Gemini North Telescope, the Subaru Telescope and the Very Large Telescope. A comparison of these results clarifies the physical properties responsible for the observed emissions, i.e. variability of the temperature field, the cloud field or the distribution of gaseous ammonia. Cross-references to the visible cloud field from Juno's JunoCam experiment and Earth-based images are also useful. This work continues an initial comparison by Orton et al. (2017, GRL 44, doi: 10.1002/2017GL073019) between MWR and JIRAM results, together with ancillary 5-µm IRTF imaging and with JunoCam and ground-based visible imaging. These showed a general agreement between MWR and JIRAM results for the 5-bar NH3 abundance in specific regions of low cloud opacity but only a partial correlation between MWR and 5-µm radiances emerging from the 0.5-5 bar levels of the atmosphere in general. Similar to the latter, there appears to be an inconsistent correlation between MWR channels sensitive to 0.5-10 bars and shorter-wavelength radiances in the "tails" of 5-µm hot spots , which may be the result of the greater sensitivity of the latter to particulate opacity that could depend on the evolution history of the particular features sampled. Of great importance is the interpretation of MWR radiances in terms of the variability of temperature vs. NH3 abundances in the 0.5-5 bar pressure range. This is particularly important to understand MWR results in

  2. Ground Thermal Diffusivity Calculation by Direct Soil Temperature Measurement. Application to very Low Enthalpy Geothermal Energy Systems.

    Science.gov (United States)

    Andújar Márquez, José Manuel; Martínez Bohórquez, Miguel Ángel; Gómez Melgar, Sergio

    2016-02-29

    This paper presents a methodology and instrumentation system for the indirect measurement of the thermal diffusivity of a soil at a given depth from measuring its temperature at that depth. The development has been carried out considering its application to the design and sizing of very low enthalpy geothermal energy (VLEGE) systems, but it can has many other applications, for example in construction, agriculture or biology. The methodology is simple and inexpensive because it can take advantage of the prescriptive geotechnical drilling prior to the construction of a house or building, to take at the same time temperature measurements that will allow get the actual temperature and ground thermal diffusivity to the depth of interest. The methodology and developed system have been tested and used in the design of a VLEGE facility for a chalet with basement at the outskirts of Huelva (a city in the southwest of Spain). Experimental results validate the proposed approach.

  3. Soil water content and evaporation determined by thermal parameters obtained from ground-based and remote measurements

    Science.gov (United States)

    Reginato, R. J.; Idso, S. B.; Jackson, R. D.; Vedder, J. F.; Blanchard, M. B.; Goettelman, R.

    1976-01-01

    Soil water contents from both smooth and rough bare soil were estimated from remotely sensed surface soil and air temperatures. An inverse relationship between two thermal parameters and gravimetric soil water content was found for Avondale loam when its water content was between air-dry and field capacity. These parameters, daily maximum minus minimum surface soil temperature and daily maximum soil minus air temperature, appear to describe the relationship reasonably well. These two parameters also describe relative soil water evaporation (actual/potential). Surface soil temperatures showed good agreement among three measurement techniques: in situ thermocouples, a ground-based infrared radiation thermometer, and the thermal infrared band of an airborne multispectral scanner.

  4. A model predictive framework of Ground Source Heat Pump coupled with Aquifer Thermal Energy Storage System in heating and cooling equipment of a building

    NARCIS (Netherlands)

    Rostampour Samarin, V.; Bloemendal, J.M.; Keviczky, T.

    2017-01-01

    This paper presents a complete model of a building heating and cooling equipment and a ground source heat pump (GSHP) coupled with an aquifer thermal energy storage (ATES) system. This model contains detailed
    mathematical representations of building thermal dynamics, ATES system dynamics, heat

  5. Investigation of the thermal regime and geologic history of the Cascade volcanic arc: First phase of a program for scientific drilling in the Cascade Range

    Energy Technology Data Exchange (ETDEWEB)

    Priest, G.R.

    1987-01-01

    A phased, multihole drilling program with associated science is proposed as a means of furthering our understanding of the thermal regime and geologic history of the Cascade Range of Washington, Oregon, and northern California. The information obtained from drilling and ancillary geological and geophysical investigations will contribute to our knowledge in the following general areas: (1) the magnitude of the regional background heat flow of parts of the Quaternary volcanic belt dominated by the most abundant volcanic rock types, basalt and basaltic andesite; (2) the nature of the heat source responsible for the regional heat-flow anomaly; (3) the characteristics of the regional hydrothermal and cold-water circulation; the rates of volcanism for comparison with models for the rate and direction of plate convergence of the Cascades; (5) the history of deformation and volcanism in the volcanic arc that can be related to subduction; (6) the present-day stress regime of the volcanic arc and the relation of these stresses to plate interactions and possible large earthquakes; and the current geometry of the subducted oceanic plate below the Cascade Range and the relationship of the plate to the distribution of heat flow, Quaternary volcanism, and Quaternary deformation. Phase I research will be directed toward a detailed investigation of the Santiam Pass segment. In concert with the Santiam Pass research, a detailed study of the nearby Breitenbush Hot Springs area is also recommended as a component of Phase I. The object of the Breitenbush research is to study one of the hottest known Cascade hydrothermal systems, which coincidentally also has a good geological and geophysical data base. A coordinated program of drilling, sampling, subsurface measurements, and surface surveys will be associated with the drilling of several holes.

  6. Thermal regime of a continental permafrost associated gas hydrate occurrence a continuous temperature profile record after drilling

    Science.gov (United States)

    Henninges, J.; Huenges, E.; Mallik Working Group

    2003-04-01

    Both the size and the distribution of natural methane hydrate occurrences, as well as the release of gaseous methane through the dissociation of methane hydrate, are affected by the subsurface pressure and temperature conditions. During a field experiment, which was carried out in the Mackenzie Delta, NWT, Canada, within the framework of the Mallik 2002 Production Research Well Program*, the variation of temperature within three 40 m spaced, 1200 m deep wells was measured deploying the Distributed Temperature Sensing (DTS) technology. An innovative experimental design for the monitoring of spatial and temporal variations of temperature along boreholes was developed and successfully applied under extreme arctic conditions. A special feature is the placement of the fibre-optic sensor cable inside the cement annulus between the casing and the wall of the borehole. Temperature profiles were recorded with a sampling interval of 0.25 m and 5 min, and temperatures can be determined with a resolution of 0.3 °C. The observed variation of temperature over time shows the decay of the thermal disturbances caused by the drilling and construction of the wells. An excellent indicator for the location of the base of the ice-bonded permafrost layer, which stands out as a result of the latent heat of the frozen pore fluid, is a sharp rise in temperature at 604 m depth during the period of equilibration. A similar effect can be detected in the depth interval between 1105 m and 1110 m, which is interpreted as an indicator for the depth to the base of the methane hydrate stability zone. Nine months after the completion of the wells the measured borehole temperatures are close to equilibrium. The mean temperature gradient rises from 9.4 K/km inside the permafrost to 25.4 K/km in the ice-free sediment layers underneath. The zone of the gas hydrate occurrences between 900 m and 1100 m shows distinct variations of the geothermal gradient, which locally rises up to 40 K/km. At the lower

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  8. Flow regimes

    International Nuclear Information System (INIS)

    Liles, D.R.

    1982-01-01

    Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced

  9. Mycoplasmal upper respiratory tract disease across the range of the threatened Mojave Desert tortoise: associations with thermal regime and natural antibodies.

    Science.gov (United States)

    Sandmeier, Franziska C; Tracy, C Richard; Hagerty, Bridgette E; DuPré, Sally; Mohammadpour, Hamid; Hunter, Kenneth

    2013-03-01

    Most research of upper respiratory tract disease (mycoplasmal URTD) in the threatened Mojave Desert tortoise (Gopherus agassizii) has worked under the hypothesis that the pathogen, Mycoplasma agassizii, has a relatively consistent and predictable effect on tortoise populations across their natural range. In contrast, we hypothesized that multiple factors influence the prevalence of disease and analyzed biological and environmental variables that vary significantly across the Mojave Desert. We used multiple regression models to analyze associations between mycoplasmal URTD and the genetic structure of 24 tortoise populations, levels of natural antibody (NAb) to M. agassizii in tortoises (one component of the innate immune system), precipitation, and colder thermal regimes. We detected a significant, positive association between mean levels of NAb and seroprevalence to M. agassizii. We hypothesized that NAbs may provide tolerance to mycoplasmal infections and that more tolerant populations may act as host reservoirs of disease. We also detected significant associations between colder winters and mycoplasmal URTD, suggesting that colder winters may depress tortoise immune resistance against M. agassizii or enhance conditions for the growth of M. agassizii.

  10. Thin ice clouds in the Arctic: cloud optical depth and particle size retrieved from ground-based thermal infrared radiometry

    Directory of Open Access Journals (Sweden)

    Y. Blanchard

    2017-06-01

    Full Text Available Multiband downwelling thermal measurements of zenith sky radiance, along with cloud boundary heights, were used in a retrieval algorithm to estimate cloud optical depth and effective particle diameter of thin ice clouds in the Canadian High Arctic. Ground-based thermal infrared (IR radiances for 150 semitransparent ice clouds cases were acquired at the Polar Environment Atmospheric Research Laboratory (PEARL in Eureka, Nunavut, Canada (80° N, 86° W. We analyzed and quantified the sensitivity of downwelling thermal radiance to several cloud parameters including optical depth, effective particle diameter and shape, water vapor content, cloud geometric thickness and cloud base altitude. A lookup table retrieval method was used to successfully extract, through an optimal estimation method, cloud optical depth up to a maximum value of 2.6 and to separate thin ice clouds into two classes: (1 TIC1 clouds characterized by small crystals (effective particle diameter  ≤  30 µm, and (2 TIC2 clouds characterized by large ice crystals (effective particle diameter  >  30 µm. The retrieval technique was validated using data from the Arctic High Spectral Resolution Lidar (AHSRL and Millimeter Wave Cloud Radar (MMCR. Inversions were performed over three polar winters and results showed a significant correlation (R2 =  0.95 for cloud optical depth retrievals and an overall accuracy of 83 % for the classification of TIC1 and TIC2 clouds. A partial validation relative to an algorithm based on high spectral resolution downwelling IR radiance measurements between 8 and 21 µm was also performed. It confirms the robustness of the optical depth retrieval and the fact that the broadband thermal radiometer retrieval was sensitive to small particle (TIC1 sizes.

  11. Communication: Spin-boson model with diagonal and off-diagonal coupling to two independent baths: Ground-state phase transition in the deep sub-Ohmic regime

    International Nuclear Information System (INIS)

    Zhao, Yang; Zhao, Yang; Yao, Yao; Chernyak, Vladimir

    2014-01-01

    We investigate a spin-boson model with two boson baths that are coupled to two perpendicular components of the spin by employing the density matrix renormalization group method with an optimized boson basis. It is revealed that in the deep sub-Ohmic regime there exists a novel second-order phase transition between two types of doubly degenerate states, which is reduced to one of the usual types for nonzero tunneling. In addition, it is found that expectation values of the spin components display jumps at the phase boundary in the absence of bias and tunneling

  12. Optimization of thermal performance of a building with ground source heat pump system

    International Nuclear Information System (INIS)

    Zogou, Olympia; Stamatelos, Anastassios

    2007-01-01

    Component optimization studies during the last twenty years, point to the use of carefully optimized ground source heat pump systems as a means of reducing building heating and cooling energy costs. Modern computational tools enable building energy simulation with a time step of the order of minutes. This allows improved insight in the building HVAC system's transient operation and may affect the form of the objective functions employed in the component optimization procedure. In this paper, the yearly performance of a 3-zone residential building located in Volos, Greece, equipped with a conventional chiller-boiler system, compared to that of an alternative, ground source heat pump system, are simulated in the TRNSYS 16 environment. Comparative year-round simulations are employed to demonstrate the expected transient and overall energy balance effects of control settings, chiller or heat pump COP characteristics, equipment sizing and other design parameters. It is concluded that detailed simulation of the HVAC system operation further improves our understanding of its transient operation. Furthermore, it allows more realistic system's sizing, better assessment of the effect of control settings, chiller or heat pump COP characteristics and other design parameters

  13. Optimization of thermal performance of a building with ground source heat pump system

    Energy Technology Data Exchange (ETDEWEB)

    Zogou, Olympia; Stamatelos, Anastassios [University of Thessaly, Volos (Greece). Department of Mechanical Engineering

    2007-11-15

    Component optimization studies during the last twenty years, point to the use of carefully optimized ground source heat pump systems as a means of reducing building heating and cooling energy costs. Modern computational tools enable building energy simulation with a time step of the order of minutes. This allows improved insight in the building HVAC system's transient operation and may affect the form of the objective functions employed in the component optimization procedure. In this paper, the yearly performance of a 3-zone residential building located in Volos, Greece, equipped with a conventional chiller-boiler system, compared to that of an alternative, ground source heat pump system, are simulated in the TRNSYS 16 environment. Comparative year-round simulations are employed to demonstrate the expected transient and overall energy balance effects of control settings, chiller or heat pump COP characteristics, equipment sizing and other design parameters. It is concluded that detailed simulation of the HVAC system operation further improves our understanding of its transient operation. Furthermore, it allows more realistic system's sizing, better assessment of the effect of control settings, chiller or heat pump COP characteristics and other design parameters. (author)

  14. Thermal and antimicrobial properties of chitosan-nanocellulose films for extending shelf life of ground meat.

    Science.gov (United States)

    Dehnad, Danial; Mirzaei, Habibollah; Emam-Djomeh, Zahra; Jafari, Seid-Mahdi; Dadashi, Saeed

    2014-08-30

    Chitosan-nanocellulose biocomposites were prepared from chitosan having molecular weight of 600-800 kDa, nanocellulose with 20-50 nm diameters and various levels of 30, 60 and 90% (v/wCHT) for glycerol. Agitation and sonication were used to facilitate even dispersion of particles in the polymer matrix. The nanocomposites were examined by differential scanning calorimetry, X-ray diffraction and agar disc diffusion tests; finally, the film was applied on the surface of ground meat to evaluate its performance in real terms. Chitosan-nanocellulose nanocomposites showed high Tg range of 115-124°C and were able to keep their solid state until the temperature (Tm) range of 97-99°C. XRD photographs revealed that nanocellulose peak completely disappeared after their addition to chitosan context. Agar disc diffusion method proved that the nancomposite had inhibitory effects against both gram-positive (S. aureus) and gram-negative (E. coli and S. enteritidis) bacteria through its contact area. Application of chitosan-nanocellulose nanocomposite on the ground meat decreased lactic acid bacteria population compared with nylon packaged samples up to 1.3 and 3.1 logarithmic cycles at 3 and 25°C after 6 days of storage, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Multiple Asteroid Systems: Dimensions and Thermal Properties from Spitzer Space Telescope and Ground-based Observations

    Science.gov (United States)

    Marchis, F.; Enriquez, J. E.; Emery, J. P.; Mueller, M.; Baek, M.; Pollock, J.; Assafin, M.; Matins, R. Vieira; Berthier, J.; Vachier, F.; hide

    2012-01-01

    We collected mid-IR spectra from 5.2 to 38 microns using the Spitzer Space Telescope Infrared Spectrograph of 28 asteroids representative of all established types of binary groups. Photometric light curves were also obtained for 14 of them during the Spitzer observations to provide the context of the observations and reliable estimates of their absolute magnitudes. The extracted mid-IR spectra were analyzed using a modified standard thermal model (STM) and a thermophysical model (TPM) that takes into account the shape and geometry of the large primary at the time of the Spitzer observation. We derived a reliable estimate of the size, albedo, and beaming factor for each of these asteroids, representing three main taxonomic groups: C, S, and X. For large (volume-equivalent system diameter Deq > 130 km) binary asteroids, the TPM analysis indicates a low thermal inertia (Lambda thermally insulating regolith. The smaller (surface-equivalent system diameter Deff < 17 km) asteroids also show some emission lines of minerals, but they are significantly weaker, consistent with regoliths with coarser grains, than those of the large binary asteroids. The average bulk densities of these multiple asteroids vary from 0.7-1.7 g/cu cm (P-, C-type) to approx. 2 g/cu cm (S-type). The highest density is estimated for the M-type (22) Kalliope (3.2 +/- 0.9 g/cu cm). The spectral energy distributions (SEDs) and emissivity spectra, made available as a supplement document, could help to constrain the surface compositions of these asteroids.

  16. Drought stress determination of crops by means of ground based thermal remote sensing

    Science.gov (United States)

    Weihs, P.; Linke, R.; Richter, K.; Eitzinger, J.; Berger, L.; Besnard, T.

    2009-04-01

    Drought stress is known to have a restricting effect on plant growth and thus inevitably decreases crop yield. In the presence of drought stress, occurring whenever the evaporative demand of the atmosphere can no longer be met by the water uptake of the plant, transpiration rates of the leaves are reduced leading to higher leaf-temperatures. Remote Sensing in the thermal infrared region has been proved to be useful for acquiring information about canopy temperature and thus crop condition. Consequently, the adequate interpretation of these observations provides an instrument for irrigation scheduling, needed to avoid the negative effects of yield losses and to support a sustainable use of water in agriculture. In this study, thermal measurements by means of CIR-5 were routinely performed during the growth period from May to July 2006, on an irrigated and a rainfed wheat (Triticum aestivum L. (cv. Xenos)) plot at the study test site ‘Augarten', Vienna. Physiological measurements, such as leaf water potential and relative water content, were performed on the youngest fully expanded leaf at the three developmental stages. Additionally, spectral measurements with a portable field spectrometer were performed and meteorological data including net radiation and shortwave global radiation were continuously recorded. The objective of the present study was to assess the potential of crop water stress indices (CWSI, WDI) to determine the level of drought stress and thus irrigation needs. The results of the analyses will be presented and discussed, also in terms of a potential application in irrigation management systems.

  17. Selecting Canopy Zones and Thresholding Approaches to Assess Grapevine Water Status by Using Aerial and Ground-Based Thermal Imaging

    Directory of Open Access Journals (Sweden)

    Daniel Sepúlveda-Reyes

    2016-10-01

    Full Text Available Aerial and terrestrial thermography has become a practical tool to determine water stress conditions in vineyards. However, for proper use of this technique it is necessary to consider vine architecture (canopy zone analysis and image thresholding approaches (determination of the upper and lower baseline temperature values. During the 2014–2015 growing season, an experimental study under different water conditions (slight, mild, moderate, and severe water stress was carried out in a commercial vineyard (Vitis vinifera L., cv. Carménè. In this study thermal images were obtained from different canopy zones by using both aerial (>60 m height and ground-based (sunlit, shadow and nadir views thermography. Using customized code that was written specifically for this research, three different thresholding approaches were applied to each image: (i the standard deviation technique (SDT; (ii the energy balance technique (EBT; and (iii the field reference temperature technique (FRT. Results obtained from three different approaches showed that the EBT had the best performance. The EBT was able to discriminate over 95% of the leaf material, while SDT and FRT were able to detect around 70% and 40% of the leaf material, respectively. In the case of canopy zone analysis, ground-based nadir images presented the best correlations with stomatal conductance (gs and stem water potential (Ψstem, reaching determination coefficients (r2 of 0.73 and 0.82, respectively. The best relationships between thermal indices and plant-based variables were registered during the period of maximum atmospheric demand (near veraison with significant correlations for all methods.

  18. Use and usability of experimental monitoring data and temperature modeling to inform adaptive management of the Colorado River's thermal regime for native fish conservation below Glen Canyon Dam

    Science.gov (United States)

    Melis, T. S.

    2014-12-01

    Seasonal thermal variability of the Colorado River in Grand Canyon was severely decreased by closure of Glen Canyon Dam and filling of Lake Powell reservoir that was achieved in 1980. From 1973 to 2002, downstream summer river temperatures at Lees Ferry were about 18°C below pre-dam conditions, and limited juvenile native fish growth and survival. A large-scale flow experiment to improve the river's thermal regime for spawning and rearing habitat of endangered native humpback chub and other native fish in eastern Grand Canyon was conducted in Water Year 2000. Monitoring revealed warming, but well below the 16-18°C optimum for chub 124 km below the dam near the Little Colorado River confluence, and no measurable chub population increase in Grand Canyon. Fall-timed stable flow experiments to improve shoreline chub nursery habitat (2008-12) were also inconclusive relative to juvenile chub growth and recruitment. Field studies also showed that daytime warming of shoreline habitats used by fish under steady flows is limited by high daily exchange rates with main channel water. Monthly averaged and higher resolution temperature models have also been developed and used to support more recent experimental management planning. Temperature simulations have been useful for screening dam release scenarios under varied reservoir storage conditions with and without use of previously proposed but never constructed multilevel intake structures on the dam's hydroelectric units. Most importantly, modeling revealed the geophysical limits on downstream warming under existing water management and dam operating policies. Hourly unsteady flow simulations in 2006 predicted equivalent levels of average downstream river warming under either fluctuating or steady flows for a given monthly release volume. River warming observed since 2002, has resulted from reduced Lake Powell storage resulting from drier upper basin hydrology. In support of new environmental compliance on dam operations

  19. Water, lithium and trace element compositions of olivine from Lanzo South replacive mantle dunites (Western Alps): New constraints into melt migration processes at cold thermal regimes

    Science.gov (United States)

    Sanfilippo, Alessio; Tribuzio, Riccardo; Ottolini, Luisa; Hamada, Morihisa

    2017-10-01

    Replacive mantle dunites are considered to be shallow pathways for extraction of mantle melts from their source region. Dunites offer a unique possibility to unravel the compositional variability of the melts produced in the upper mantle, before mixing and crystal fractionation modify their original signature. This study includes a quantification of H2O, Li and trace elements (Ni, Mn, Co, Sc, V, Ti, Zr, Y and HREE) in olivine from large replacive dunite bodies (>20 m) within a mantle section exposed in the Western Italian Alps (Lanzo South ophiolite). On the basis of olivine, clinopyroxene and spinel compositions, these dunites were previously interpreted to be formed by melts with a MORB signature. Variations in Ni, Mn, Co and Ca contents in olivine from different dunite bodies suggested formation by different melt batches. The variable H2O and Li contents of these olivines agree with this idea. Compared to olivine from residual peridotites and olivine phenocrysts in MORB (both having H2O 1 ppm), the Lanzo South dunite olivine has high H2O (18-40 ppm) and low Li (0.35-0.83 ppm) contents. Geochemical modelling suggests that the dunite-forming melts were produced by low melting degrees of a mixed garnet-pyroxenite-peridotite mantle source, with a contribution of a garnet pyroxenite component variable from 20 to 80%. The Lanzo dunites experienced migration of melts geochemically enriched and mainly produced in the lowermost part of the melting region. Extraction of enriched melts through dunite channels are probably characteristic of cold thermal regimes, where low temperatures and a thick mantle lithosphere inhibit mixing with melts produced at shallower depths.

  20. Testing of ground fault relay response during the energisation of megawatt range electric boilers in thermal power plants

    DEFF Research Database (Denmark)

    Silva, Filipe Miguel Faria da; Bak, Claus Leth; Davidsen, Troels

    2015-01-01

    Large controllable loads may support power systems with an increased penetration of fluctuating renewable energy, by providing a rapid response to a change in the power production. Megawatt range electric boilers are an example of such controllable loads, capable of change rapidly, with the advan......Large controllable loads may support power systems with an increased penetration of fluctuating renewable energy, by providing a rapid response to a change in the power production. Megawatt range electric boilers are an example of such controllable loads, capable of change rapidly......, with the advantage that the warmed water can be reused in a thermal power plant or at regional heating, thus, minimising the overall losses. However, one problem was raised by those purchasing the boilers, mainly the possibility of an unwanted triggering of the protections relays, especially ground fault protection......, during the energisation of a boiler. A special case for concern was the presence of an electric arc between the electrodes of the boiler and the water in the boiler during approximately 2s at the energisation, which can in theory be seen as a ground fault by the relay. The voltage and current transient...

  1. Regime change?

    International Nuclear Information System (INIS)

    Pilat, Joseph F.; Budlong-Sylvester, K.W.

    2004-01-01

    Following the 1998 nuclear tests in South Asia and later reinforced by revelations about North Korean and Iraqi nuclear activities, there has been growing concern about increasing proliferation dangers. At the same time, the prospects of radiological/nuclear terrorism are seen to be rising - since 9/11, concern over a proliferation/terrorism nexus has never been higher. In the face of this growing danger, there are urgent calls for stronger measures to strengthen the current international nuclear nonproliferation regime, including recommendations to place civilian processing of weapon-useable material under multinational control. As well, there are calls for entirely new tools, including military options. As proliferation and terrorism concerns grow, the regime is under pressure and there is a temptation to consider fundamental changes to the regime. In this context, this paper will address the following: Do we need to change the regime centered on the Treaty on the Nonproliferation of Nuclear Weapons (NPT) and the International Atomic Energy Agency (IAEA)? What improvements could ensure it will be the foundation for the proliferation resistance and physical protection needed if nuclear power grows? What will make it a viable centerpiece of future nonproliferation and counterterrorism approaches?

  2. Satellite and Ground Based Thermal Observation of the 2014 Effusive Eruption at Stromboli Volcano

    Directory of Open Access Journals (Sweden)

    Klemen Zakšek

    2015-12-01

    Full Text Available As specifically designed platforms are still unavailable at this point in time, lava flows are usually monitored remotely with the use of meteorological satellites. Generally, meteorological satellites have a low spatial resolution, which leads to uncertain results. This paper presents the first long term satellite monitoring of active lava flows on Stromboli volcano (August–November 2014 at high spatial resolution (160 m and relatively high temporal resolution (~3 days. These data were retrieved by the small satellite Technology Experiment Carrier-1 (TET-1, which was developed and built by the German Aerospace Center (DLR. The satellite instrument is dedicated to high temperature event monitoring. The satellite observations were accompanied by field observations conducted by thermal cameras. These provided short time lava flow dynamics and validation for satellite data. TET-1 retrieved 27 datasets over Stromboli during its effusive activity. Using the radiant density approach, TET-1 data were used to calibrate the MODVOLC data and estimate the time averaged lava discharge rate. With a mean output rate of 0.87 m3/s during the three-month-long eruption, we estimate the total erupted volume to be 7.4 × 106 m3.

  3. Evaluation of VIIRS and MODIS Thermal Emissive Band Calibration Stability Using Ground Target

    Directory of Open Access Journals (Sweden)

    Sriharsha Madhavan

    2016-02-01

    Full Text Available The S-NPP Visible Infrared Imaging Radiometer Suite (VIIRS instrument, a polar orbiting Earth remote sensing instrument built using a strong MODIS background, employs a similarly designed on-board calibrating source—a V-grooved blackbody for the Thermal Emissive Bands (TEB. The central wavelengths of most VIIRS TEBs are very close to those of MODIS with the exception of the 10.7 µm channel. To ensure the long term continuity of climate data records derived using VIIRS and MODIS TEB, it is necessary to assess any systematic differences between the two instruments, including scenes with temperatures significantly lower than blackbody operating temperatures at approximately 290 K. Previous work performed by the MODIS Characterization Support Team (MCST at NASA/GSFC used the frequent observations of the Dome Concordia site located in Antarctica to evaluate the calibration stability and consistency of Terra and Aqua MODIS over the mission lifetime. The near-surface temperature measurements from an automatic weather station (AWS provide a direct reference useful for tracking the stability and determining the relative bias between the two MODIS instruments. In this study, the same technique is applied to the VIIRS TEB and the results are compared with those from the matched MODIS TEB. The results of this study show a small negative bias when comparing the matching VIIRS and Aqua MODIS TEB, implying a higher brightness temperature for S-VIIRS at the cold end. Statistically no significant drift is observed for VIIRS TEB performance over the first 3.5 years of the mission.

  4. Evaluation of drought and UV radiation impacts on above-ground biomass of mountain grassland by spectral reflectance and thermal imaging techniques

    Czech Academy of Sciences Publication Activity Database

    Novotná, Kateřina; Klem, Karel; Holub, Petr; Rapantová, Barbora; Urban, Otmar

    2016-01-01

    Roč. 9, 1-2 (2016), s. 21-30 ISSN 1803-2451 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : above-ground biomass * drought stress * grassland * UV radiation * precipitation * spectral reflectance * thermal imaging Subject RIV: EH - Ecology, Behaviour

  5. Neural network model for thermal inactivation of Salmonella Typhimurium to elimination in ground chicken: Acquisition of data by whole sample enrichment, miniature most-probable-number method

    Science.gov (United States)

    Predictive models are valuable tools for assessing food safety. Existing thermal inactivation models for Salmonella and ground chicken do not provide predictions above 71 degrees C, which is below the recommended final cooked temperature of 73.9 degrees C. They also do not predict when all Salmone...

  6. The Radiation Problem from a Vertical Hertzian Dipole Antenna above Flat and Lossy Ground: Novel Formulation in the Spectral Domain with Closed-Form Analytical Solution in the High Frequency Regime

    Directory of Open Access Journals (Sweden)

    K. Ioannidi

    2014-01-01

    Full Text Available We consider the problem of radiation from a vertical short (Hertzian dipole above flat lossy ground, which represents the well-known “Sommerfeld radiation problem” in the literature. The problem is formulated in a novel spectral domain approach, and by inverse three-dimensional Fourier transformation the expressions for the received electric and magnetic (EM field in the physical space are derived as one-dimensional integrals over the radial component of wavevector, in cylindrical coordinates. This formulation appears to have inherent advantages over the classical formulation by Sommerfeld, performed in the spatial domain, since it avoids the use of the so-called Hertz potential and its subsequent differentiation for the calculation of the received EM field. Subsequent use of the stationary phase method in the high frequency regime yields closed-form analytical solutions for the received EM field vectors, which coincide with the corresponding reflected EM field originating from the image point. In this way, we conclude that the so-called “space wave” in the literature represents the total solution of the Sommerfeld problem in the high frequency regime, in which case the surface wave can be ignored. Finally, numerical results are presented, in comparison with corresponding numerical results based on Norton’s solution of the problem.

  7. Spin frustration of a spin-1/2 Ising–Heisenberg three-leg tube as an indispensable ground for thermal entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Strečka, Jozef, E-mail: jozef.strecka@upjs.sk [Department of Theoretical Physics and Astrophysics, Faculty of Science, P.J. Šafárik University, Park Angelinum 9, 040 01 Košice (Slovakia); Alécio, Raphael Cavalcante; Lyra, Marcelo L. [Instituto de Física, Universidade Federal de Alagoas, 57072-970 Maceio-AL (Brazil); Rojas, Onofre [Departamento de Física, Universidade Federal de Lavras, 37200-000 Lavras-MG (Brazil)

    2016-07-01

    The spin-1/2 Ising–Heisenberg three-leg tube composed of the Heisenberg spin triangles mutually coupled through the Ising inter-triangle interaction is exactly solved in a zero magnetic field. By making use of the local conservation for the total spin on each Heisenberg spin triangle the model can be rigorously mapped onto a classical composite spin-chain model, which is subsequently exactly treated through the transfer-matrix method. The ground-state phase diagram, correlation functions, concurrence, Bell function, entropy and specific heat are examined in detail. It is shown that the spin frustration represents an indispensable ground for a thermal entanglement, which is quantified by the quantum concurrence. The specific heat displays diverse temperature dependences, which may include a sharp low-temperature peak mimicking a temperature-driven first-order phase transition. It is convincingly evidenced that this anomalous peak originates from massive thermal excitations from the doubly degenerate ground state towards an excited state with a high macroscopic degeneracy due to chiral degrees of freedom of the Heisenberg spin triangles. - Highlights: • Spin-1/2 Ising–Heisenberg three-leg tube is exactly solved in a zero magnetic field. • Thermal entanglement is only present in a frustrated part of the parameter space. • Spin frustration and thermal entanglement show antagonistic reentrance. • Specific heat may display a sharp narrow peak due to massive thermal excitations.

  8. WFC3 Science Calibration Plan Part 1: Overview of Ground-Based Ambient and Thermal Vacuum Calibration Tests

    Science.gov (United States)

    Reid, Iain Neill

    2002-05-01

    The goals of the WFC3 ground-based calibration effort are to perform a comprehensive instrument characterization to verify CEI performance, to understand the operational characteristics of the instrument, and to create calibration reference files that will serve as a baseline for on-orbit calibrations and data pipeline processing. The plan is based on the extensive experience and groundwork laid by the WFPC2, NICMOS, STIS and ACS instruments. As with ACS and WFPC2, this Calibration Plan emphasizes a suite of nine test categories. The suite of test categories includes a comprehensive characterization of all essential science performance parameters, and encompasses measurements conducted at component, subassembly and systems levels, and carried out in both ambient and thermal vacuum environments. Detailed test procedures will identify the desired WFC3 instrument configuration, the Optical Stimulus configuration, and the Exposure Time Calculator (ETC) estimates of exposure times for each of the measurements required. Our approach is to implement a "test as you build" approach. Given the schedule and budget constrained WFC3 program, this approach provides the opportunity to perform trouble shooting and noise debugging at the earliest possible opportunity, and to identify potential problems and implement solutions in a timely manner before launch. The overall integration and testing program makes use of facilities and Ground Support Equipment (GSE) at Ball, JPL and GSFC, using hardware and software tools developed for previous HST instruments. Using lessons learned from previous HST instruments, we plan to implement improvements in the data handling process to increase efficiency and assure data quality. This document addresses primarily those tests and calibration measurements that will be done at GSFC to ensure that WFC3 will be able to complete its scientific mission.

  9. Evaluation of the thermal efficiency and a cost analysis of different types of ground heat exchangers in energy piles

    International Nuclear Information System (INIS)

    Yoon, Seok; Lee, Seung-Rae; Xue, Jianfeng; Zosseder, Kai; Go, Gyu-Hyun; Park, Hyunku

    2015-01-01

    Highlights: • We performed field TPT with W and coil-type GHEs in energy piles. • We evaluated heat exchange rates from TPT results. • Field TPT results were compared with numerical analysis. • Cost analysis with GSHP design method was conducted for each type of GHEs in energy piles. - Abstract: This paper presents an experimental and numerical study of the results of a thermal performance test using precast high-strength concrete (PHC) energy piles with W and coil-type ground heat exchangers (GHEs). In-situ thermal performance tests (TPTs) were conducted for four days under an intermittent operation condition (8 h on; 16 h off) on W and coil-type PHC energy piles installed in a partially saturated weathered granite soil deposit. In addition, three-dimensional finite element analyses were conducted and the results were compared with the four-day experimental results. The heat exchange rates were also predicted for three months using the numerical analysis. The heat exchange rate of the coil-type GHE showed 10–15% higher efficiency compared to the W-type GHE in the energy pile. However, in considering the cost for the installation of the heat exchanger and cement grouting the additional cost of W-type GHE in energy pile was 200–250% cheaper than coil-type GHE under the condition providing equivalent thermal performance. Furthermore, the required lengths of the W, 3U and coil-type GHEs in the energy piles were calculated based on the design process of Kavanaugh and Rafferty. The additional cost for the W and 3U types of GHEs were also 200–250% lower than that of the coil-type GHE. However, the required number of piles was much less with the coil-type GHE as compared to the W and 3U types of GHEs. They are advantageous in terms of the construction period, and further, selecting the coil-type GHE could be a viable option when there is a limitation in the number of piles in consideration of the scale of the building.

  10. Spatial and optical parameters of contrails in the vortex and dispersion regime determined by means of a ground-based scanning lidar

    Energy Technology Data Exchange (ETDEWEB)

    Freudenthaler, V.; Homburg, F.; Jaeger, H. [Fraunhofer-Inst. fuer Atmosphaerische Umweltforschung (IFU), Garmisch-Partenkirchen (Germany)

    1997-12-31

    The spatial growth of individual condensation trails (contrails) of commercial aircrafts in the time range from 15 s to 60 min behind the aircraft is investigated by means of a ground-based scanning backscatter lidar. The growth in width is mainly governed by wind shear and varies between 18 m/min and 140 m/min. The growth of the cross-section varies between 3500 m{sup 2}/min and 25000 m{sup 2}/min. These values are in agreement with results of model calculations and former field measurements. The vertical growth is often limited by boundaries of the humid layer at flight level, but values up to 18 m/min were observed. Optical parameters like depolarization, optical depth and lidar ratio, i.e. the extinction-to-backscatter ratio, have been retrieved from the measurements at a wavelength of 532 nm. The linear depolarization rises from values as low as 0.06 for a young contrail (10 s old) to values around 0.5, typical for aged contrails. The latter indicates the transition from non-crystalline to crystalline particles in persistent contrails within a few minutes. The scatter of depolarization values measured in individual contrails is narrow, independent of the contrails age, and suggests a rather uniform growth of the particles inside a contrail. (author) 18 refs.

  11. On the regimes of premixing

    Energy Technology Data Exchange (ETDEWEB)

    Angelini, S.; Theofanous, T.G.; Yuen, W.W. [California Univ., Santa Barbara, CA (United States). Center for Risk Studies and Safety

    1998-01-01

    The conditions of the MAGICO-2000 experiment are extended to more broadly investigate the regimes of premixing, and the corresponding internal structures of mixing zones. With the help of the data and numerical simulations using the computer code PM-ALPHA, we can distinguish extremes of behavior dominated by inertia and thermal effects - we name these the inertia and thermal regimes, respectively. This is an important distinction that should guide future experiments aimed at code verification in this area. Interesting intermediate behaviors are also delineated and discussed. (author)

  12. Primary productivity, heterotrophy, metabolic indicators of stress and interactions in algal-bacterial mat communities affected by a fluctuating thermal regime

    International Nuclear Information System (INIS)

    Tison, D.L.

    1980-01-01

    Thermal habitats in effluent cooling waters from production nuclear reactors at the Savannah River Plant are unlike natural thermal habitats in that reactor operations are periodically halted, exposing the organisms growing in these thermal habitats to ambient temperatures for unpredictable lengths of time. Rates of primary production, glucose heterotrophy, and the composition of algal-bacterial mat communities growing along a thermal gradient from about 50 to 35 0 C during periods of reactor operation were studied. Cyanobacteria were the only photoautotrophs in mat communities above 40 0 C while cyanobacteria and eucaryotic algae comprised the photoautotrophic component of mat communities below 40 0 C. The heterotrophic component of these communities above 40 0 C was made up of stenothermic and eurythermic thermophilic bacteria while both eurythermic thermophiles and mesophilic bacteria were found in communities below 40 0 C. Net CO 2 -fixation rates during thermal conditions dropped after initial exposure to ambient temperatures. After prolonged exposure of the thermal communities to ambient temperatures, adaptation and colonization by mesophilic algae occurred. Rates of glucose utilization under varying degrees of thermal influence suggested that the heterotrophic component may not have been optimally adapted to thermal conditions. During periods of changing thermal conditions, an increase in the percentage extracellular release of photosynthetically fixed 14 CO 2 by cyanobacteria and algae and an increase in the percentage of glucose mineralized (respired) by the heterotrophic component of the mat communities was observed. Results of temperature shift experiments indicated that the short-term response of the photoautotrophic component of these communities to thermal stress was an increase in the percentage of photosynthate released extracellularly

  13. Energy saving in the auxiliaries consumption for circulation water pumps optimizing the thermal regime; Ahorro en el consumo de auxiliares por bombas de agua de circulacion optimando el regimen termico

    Energy Technology Data Exchange (ETDEWEB)

    Orozco Martinez, Roni [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    A methodology is proposed that should be followed in any thermal electric power plant to determine the load value at which a unit requires a second circulation water pump without affecting the thermal regime and avoiding an excessive auxiliaries consumption in partial loads. In applying this method the power plant would have an energy saving equivalent to the auxiliaries consumption during an hour, when the unit as operating at full load. [Espanol] Se propone una metodologia que debe seguirse en cualquier central termoelectrica para determinar el valor de la carga en la cual una unidad requiere de la segunda bomba de agua de circulacion sin afectar el regimen termico y evitadose un excesivo consumo de auxiliares en cargas parciales. Al aplicar este metodo la central tendria un ahorro de energia equivalente al consumo de auxiliares durante una hora cuando la unidad esta generando su maxima carga.

  14. Measurement of the rates of reaction of the ground and metastable excited states of 02+, N0+ and 0+ with atmospheric gases at thermal energy

    International Nuclear Information System (INIS)

    Glosik, J.; Rakshit, A.B.; Twiddy, N.D.; Adams, N.G.; Smith, D.

    1978-01-01

    Thermal-energy reaction rate coefficients and product ion distributions have been measured for reactions of both the ground state and metastable electronic states of 0 2 + , N0 + and 0 + with several neutral species, using a selected-ion flow tube. In general the excited-ion reaction rates are fast, frequently approaching the Langevin limit. Collisional quenching occurs for the reactions of N0 + sup(star) with N 2 ,0 2 and H 2 and the quenching rates have been determined. The ion source also provided a substantial yield of doubly charged 0 2 permitting some measurements of reaction rates of 0 2 2+ . (author)

  15. Thermal surveillance of Cascade Range volcanoes using ERTS-1 multispectral scanner, aircraft imaging systems, and ground-based data communication platforms

    Science.gov (United States)

    Friedman, J. D.; Frank, D. G.; Preble, D.; Painter, J. E.

    1973-01-01

    A combination of infrared images depicting areas of thermal emission and ground calibration points have proved to be particularly useful in plotting time-dependent changes in surface temperatures and radiance and in delimiting areas of predominantly convective heat flow to the earth's surface in the Cascade Range and on Surtsey Volcano, Iceland. In an integrated experiment group using ERTS-1 multispectral scanner (MSS) and aircraft infrared imaging systems in conjunction with multiple thermistor arrays, volcano surface temperatures are relayed daily to Washington via data communication platform (DCP) transmitters and ERTS-1. ERTS-1 MSS imagery has revealed curvilinear structures at Lassen, the full extent of which have not been previously mapped. Interestingly, the major surface thermal manifestations at Lassen are aligned along these structures, particularly in the Warner Valley.

  16. Birds in New York State Have Altered Their Migration Timing and Are Experiencing Different Thermal Regimes While Breeding or on Stopover from 2010 to 2015

    Directory of Open Access Journals (Sweden)

    Natalie Pudalov

    2017-01-01

    Full Text Available Migration represents a significant physiological challenge for birds, and increasing ambient temperatures due to global climate change may add to birds’ physiological burden during migration. We analyzed migration timing in a central New York county and two counties in the Adirondack region by using data from the citizen science network, eBird, and correlating it with historical temperature data. Species of birds sighted in Central NY (N=195 and the Adirondack region (N=199 were categorized into year-round residents and one- and two-stopover groupings based on eBird observations. Using linear regressions, we looked at various relationships between temperature and variables relating to birds’ migration across 2010–2015. Of the total 195 species used within this data in Central NY, 35 species showed some alteration in their migration timing or in the temperature regime they experienced while breeding or on migration stopover. In the Adirondack region, of the total 199 species used within this dataset, 43 species showed some alteration in their migration timing or experienced significantly colder or warmer temperatures while breeding or on migration stopover during 2010–2015. Additionally, many of the bird species affected by temperature changes in the state of New York and those that altered migration timing tended to be long-distance migrants.

  17. Drought Conditions Maximize the Impact of High-Frequency Flow Variations on Thermal Regimes and Biogeochemical Function in the Hyporheic Zone.

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2017-03-01

    Anthropogenic activities, such as dam operations, often induce larger and more frequent stage fluctuations than those occurring in natural rivers. However, the long-term impact of such flow variations on thermal and biogeochemical dynamics of the associated hyporheic zone (HZ) is poorly understood. A heterogeneous, two-dimensional thermo-hydro-biogeochemical model revealed an important interaction between high-frequency flow variations and watershed-scale hydrology. High-frequency stage fluctuations had their strongest thermal and biogeochemical impacts when the mean river stage was low during fall and winter. An abnormally thin snowpack in 2015, however, created a low river stage during summer and early fall, whereby high frequency stage fluctuations caused the HZ to be warmer than usual. This study provided the scientific basis to assess the potential ecological consequences of the high-frequency flow variations in a regulated river, as well as guidance on how to maximize the potential benefits—or minimize the drawbacks—of river regulation to river ecosystems.

  18. Seismic activity and thermal regime of low temperature fumaroles at Mt. Vesuvius in 2004-2011: distinguishing among seismic, volcanic and hydrological signals

    Directory of Open Access Journals (Sweden)

    Paola Cusano

    2013-11-01

    Full Text Available Seismological, soil temperature and hydrological data from Mt. Vesuvius are collected to characterize the present-day activity of the volcanic/hydrothermal system and to detect possible unrest-related phenomena. We present patterns of seismicity and soil temperature in the crater area during the period February 2004-December 2011. The temporal distribution of number and depth of Volcano-Tectonic earthquakes and the energy release are considered. Hourly data of soil temperature have been acquired since January 2004 in different locations along the rim and within the crater. The observed changes of temperature are studied to establish a temporal-based correlation with the volcanic activity and/or with external forcing, as variations of the regional and local stress field acting on the volcano or meteorological phenomena. The comparison between seismic activity and temperature data highlights significant variations possibly related to changes in fluid circulation in the hydrothermal system of the volcano. The common continuous observations start just before a very shallow earthquake occurred in August 2005, which was preceded by a thermal anomaly. This coincidence has been interpreted as related to fluid-driven rock fracturing, as observed in other volcanoes. For the successive temporal patterns, the seismicity rate and energy release are characterized by slight variations accompanied by changes in temperature. This evidence of reactivity of the fumarole thermal field to seismic strain can be used to discriminate between tectonic and volcanic signals at Mt. Vesuvius.

  19. Influence of litter layer removal on the soil thermal regime of a pine forest in a mediterranean climate Influência da manta morta no regime térmico de um solo sob pinus num clima do tipo mediterrâneo

    Directory of Open Access Journals (Sweden)

    José Alexandre Varanda Andrade

    2010-10-01

    Full Text Available The removal of the litter layer in Portuguese pine forests would reduce fire hazard, but on the other hand this practice would influence the thermal regime of the soil, hence affecting soil biological activity, litter decomposition and nutrient dynamics. Temperature profiles of a sandy soil (Haplic Podzol under a pine forest were measured with thermocouples at depths to 16 cm, with and without litter layer. The litter layer acted as a thermal insulator, reducing the amplitude of the periodic temperature variation in the mineral soil underneath and increasing damping depths, particularly at low soil water contents. At the mineral soil surface the reduction of amplitudes was about 2.5 ºC in the annual cycle and 5 to 6.7 ºC in the daily cycle, depending on the soil water content. When soil was both cold and wet, mean daily soil temperatures were higher (about 1 - 1.5 ºC under the litter layer. Improved soil thermal conditions under the litter layer recommend its retention as a forest management practice to follow in general.A remoção da manta morta nos pinhais portugueses pode reduzir o risco de incêndio florestal, mas essa prática pode influenciar o regime térmico do solo, alterando dessa forma a atividade biológica, a decomposição da manta morta e a dinâmica de nutrientes. Num solo arenoso (Haplic Podzol sob pinus foram medidos perfis térmicos com termopares a várias profundidades até 16 cm, com ou sem manta morta. A manta morta atuou como um isolador térmico, reduzindo a amplitude da variação periódica da temperatura na camada de solo subjacente e aumentando as profundidades de amortecimento, sobretudo em teores baixos de umidade do solo. Na superfície do solo mineral a redução das amplitudes foi de cerca de 2,5 ºC no ciclo anual e de 5 a 6,7 ºC no ciclo diário, dependendo da umidade do solo. A manta morta aumentou em cerca de 1-1,5 ºC as temperaturas médias diárias do solo mineral quando este se encontrava mais frio

  20. Operation KNOTHOLE, Nevada Proving Grounds. Project 8.4-1. Protection Afforded by Operational Smoke Screens against Thermal Radiation

    Science.gov (United States)

    1954-03-01

    copper and blackened on one face with electrolytically deposited platinum and finished with camphor black. Soldered to the center of the unblackened face...measured 6 ft above the ground using a Mine Safety Appliance Co. Electrostatic Sampler, Model F. In all preliminary +,eots the electrostatic sampler...Director of Intelligence, Handqurtora, USAF, Washing- 177 Armed Servicoa Exploalvec Safety Board, D/D, Building ton e 5 D.C. ATSo ., AF uN-192 T-7

  1. Visible and thermal spectrum synthetic image generation with DIRSIG and MuSES for ground vehicle identification training

    Science.gov (United States)

    May, Christopher M.; Maurer, Tana O.; Sanders, Jeffrey S.

    2017-05-01

    There is a ubiquitous and never ending need in the US armed forces for training materials that provide the warfighter with the skills needed to differentiate between friendly and enemy forces on the battlefield. The current state of the art in battlefield identification training is the Recognition of Combat Vehicles (ROCV) tool created and maintained by the Communications - Electronics Research, Development and Engineering Center Night Vision and Electronic Sensors Directorate (CERDEC NVESD). The ROC-V training package utilizes measured visual and thermal imagery to train soldiers about the critical visual and thermal cues needed to accurately identify modern military vehicles and combatants. This paper presents an approach that has been developed to augment the existing ROC-V imagery database with synthetically generated multi-spectral imagery that will allow NVESD to provide improved training imagery at significantly lower costs.

  2. Assessment of extreme hydrological conditions in the Bothnian Bay, Baltic Sea, and the impact of the nuclear power plant "Hanhikivi-1" on the local thermal regime

    Science.gov (United States)

    Dvornikov, Anton Y.; Martyanov, Stanislav D.; Ryabchenko, Vladimir A.; Eremina, Tatjana R.; Isaev, Alexey V.; Sein, Dmitry V.

    2017-04-01

    The results of the study aimed to assess the influence of future nuclear power plant Hanhikivi-1 upon the local thermal conditions in the Bothnian Bay in the Baltic Sea are presented. A number of experiments with different numerical models were also carried out in order to estimate the extreme hydro-meteorological conditions in the area of the construction. The numerical experiments were fulfilled both with analytically specified external forcing and with real external forcing for 2 years: a cold year (2010) and a warm year (2014). The study has shown that the extreme values of sea level and water temperature and the characteristics of wind waves and sea ice in the vicinity of the future nuclear power plant can be significant and sometimes catastrophic. Permanent release of heat into the marine environment from an operating nuclear power plant will lead to a strong increase in temperature and the disappearance of ice cover within a 2 km vicinity of the station. These effects should be taken into account when assessing local climate changes in the future.

  3. Observations of a middle atmosphere thermal structure over Durban using a ground-based Rayleigh LIDAR and satellite data

    Directory of Open Access Journals (Sweden)

    Ashokabose Moorgawa

    2012-01-01

    Full Text Available Studying the middle atmospheric thermal structure over southern Africa is an important activity to improve the understanding of atmospheric dynamics of this region. Observations of a middle atmosphere thermal structure over Durban, South Africa (29.9°S, 31.0°E using the Durban Rayleigh Light Detection and Ranging (LIDAR data collected over 277 nights from April 1999 to July 2004, including closest overpasses of the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER and Halogen Occultation Experiments (HALOE satellites, are presented in this paper. There seems to be good agreement between the LIDAR and satellite observations. During autumn and winter, the temperatures measured by the LIDAR in the height region between 40 km and 55 km were 5 K to 12 K higher than those measured by the satellites. The data from the LIDAR instrument and the SABER and HALOE satellites exhibited the presence of an annual oscillation in the stratosphere, whereas in the mesosphere, semi-annual oscillations dominated the annual oscillation at some levels. The stratopause was observed in the height range of ~40 km – 55 km by all the instruments, with the stratopause temperatures measured as 260 K – 270 K by the LIDAR, 250 K – 260 K by the SABER and 250 K – 270 K by the HALOE. Data from the SABER and HALOE satellites indicated almost the same thermal structure for the middle atmosphere over Durban.

  4. Development of a thermal hydraulic modelling of ground water of the Malm in the Munich metropolitan area; Entwicklung einer thermisch-hydraulischen Grundwassermodellierung des Malm im Grossraum Muenchen

    Energy Technology Data Exchange (ETDEWEB)

    Dussel, M.; Lueschen, E.; Thomas, R. [Leibniz-Institut fuer Angewandte Geophysik, Hannover (DE)] (and others)

    2011-10-24

    The mutual potential influence of geothermal duplicates and the scientific investigation of the relationship between seismic and hydraulic parameters are investigated in the joint research project 'Geothermal characterization of fractured karst limestone aquifers in the Munich metropolitan area'. Thirteen doublets and triplets being in production or sunk illustrate the great geothermal potential and provide important data on the development of a thermal-hydraulic modeling of the reservoir. 3D seismic Unterhaching, 3D structural model, hydrogeological model and a high-resolution 3D temperature model form the basis of the numerical modeling. Different seismic signatures, seismic attributes and variations in the interval velocities characterize the ground geophysically, and were interpreted under consideration of geological and hydrogeological background information as well as borehole measurements in terms of hydraulically conductive homogeneous areas. For the Munich metropolitan area, the numerical modeling is a decision aid for the future optimized and sustainable hydrothermal utilization of the Malm aquifer.

  5. Noncontact electrosurgical grounding--a useful and safe tool in the initial surgical management of thermal injuries.

    Science.gov (United States)

    Liodaki, E; Stang, F H; Lohmeyer, J A; Bergmann, P A; Mailänder, P; Siemers, F

    2013-02-01

    Electrosurgical instruments - one of the useful and most-used instruments within the surgeon's armamentarium - are potentially dangerous by causing unanticipated direct burns; fire occurring as a result of electrosurgical instruments and electromagnetic interference with a pacemaker, defibrillator, or cardiac monitoring device. The Mega 2000 Patient Return Electrode System produced by Megadyne Medical Products is a noncontact electrode designed to provide adequate electrical return to facilitate function of electrocautery devices. We used this noncontact device in 67 patients (28 women, 39 men) with large burns during their stay in our burn unit and in 11 of these patients (4 women, 7 men) for escharotomies during admission in our burn care. The device functioned well in all cases, no additional cutaneous burns on the patients' body were noticed. This paper is a review of our experience with this noncontact electrosurgical grounding in burn surgery highlighting its advantages comparing with the conventional electrosurgical instruments. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  6. Characterization of Alkaline Treatment and Fiber Content on the Physical, Thermal, and Mechanical Properties of Ground Coffee Waste/Oxobiodegradable HDPE Biocomposites

    Directory of Open Access Journals (Sweden)

    Ming Yee Tan

    2017-01-01

    Full Text Available Effect of alkali treatment on ground coffee waste/oxobiodegradable HDPE (GCW/oxo-HDPE composites was evaluated using 5%, 10%, 15%, and 20% volume fraction of GCW. The composites were characterized using structural (Fourier transform infrared spectroscopy (FTIR and scanning electron microscopy (SEM, thermal (thermogravimetric analysis (TGA and differential scanning calorimetry (DSC, mechanical (tensile and impact test properties, and water absorption. FTIR spectrum indicated the eradication of lipids, hemicellulose, lignin, and impurities after the treatments lead to an improvement of the filler/matrix interface adhesion. This is confirmed by SEM results. Degree of crystallinity index was increased by 5% after the treatment. Thermal stability for both untreated and treated GCW composites was alike. Optimum tensile result was achieved when using 10% volume fraction with enhancement of 25% for tensile strength and 24% for tensile modulus compared to untreated composite. Specific tensile strength and modulus had improved as the composite has lower density. The highest impact properties were achieved when using 15% volume fraction that lead to an improvement of 6%. Treated GCW composites show better water resistance with 57% improvement compared to the untreated ones. This lightweight and ecofriendly biocomposite has the potential in packaging, internal automotive parts, lightweight furniture, and other composite engineering applications.

  7. Synergies between nonproliferation regimes: A pragmatic approach

    International Nuclear Information System (INIS)

    Findlay, Trevor; Meier, Oliver

    2001-01-01

    Full text: With the recent progress in establishing international nonproliferation regimes, the question of synergies between different verification and monitoring regimes is becoming more acute. Three multilateral and universal nonproliferation organisations covering safeguards on civil nuclear materials, nuclear testing, and chemical weapons are up and running. A regime on biological weapons is under negotiation. Several regional organisations concerned with monitoring nonproliferation commitments in the nuclear field are in place; others are being established. Past discussions on synergies between these regimes have suffered from being too far-reaching. These discussions often have not reflected adequately the political difficulties of cooperation between regimes with different membership, scope and institutional set-up. This paper takes a pragmatic look at exploiting synergies and identifies some potential and real overlaps in the work between different verification regimes. It argues for a bottom-up approach and identifies building blocks for collaboration between verification regimes. By realising such, more limited potential for cooperation, the ground could be prepared for exploiting other synergies between these regimes. (author)

  8. Prospect of Thermal Insulation by Silica Aerogel: A Brief Review

    Science.gov (United States)

    Hasan, Mohammed Adnan; Sangashetty, Rashmi; Esther, A. Carmel Mary; Patil, Sharanabasappa B.; Sherikar, Baburao N.; Dey, Arjun

    2017-10-01

    Silica aerogel is a unique ultra light weight nano porous material which offers superior thermal insulation property as compared to the conventional thermal insulating materials. It can be applied not only for ground and aerospace applications but also in low and high temperatures and pressure regimes. Aerogel granules and monolith are synthesized by the sol-gel route while aerogel based composites are fabricated by the reinforcement of fibers, particle and opacifiers. Due to the characteristic brittleness (i.e., poor mechanical properties) of monolith or bulk aerogel, it is restricted in several applications. To improve the mechanical integrity and flexibility, usually different fibers are reinforced with aerogel and hence it can be used as flexible thermal insulation blankets. Further, to achieve effective thermal insulation behaviour particularly at high temperature, often opacifiers are doped with silica aerogel. In the present brief review, the prospects of bulk aerogel and aerogel based composites are discussed for the application of thermal insulation and thermal stability.

  9. Sustainable urban regime adjustments

    DEFF Research Database (Denmark)

    Quitzau, Maj-Britt; Jensen, Jens Stissing; Elle, Morten

    2013-01-01

    The endogenous agency that urban governments increasingly portray by making conscious and planned efforts to adjust the regimes they operate within is currently not well captured in transition studies. There is a need to acknowledge the ambiguity of regime enactment at the urban scale. This direc...

  10. Small Business Tax Regimes

    OpenAIRE

    Yilmaz, Fatih; Coolidge, Jacqueline

    2016-01-01

    Simplified tax regimes for micro and small enterprises in developing countries are intended to facilitate voluntary tax compliance. However, survey evidence suggests that small business taxation based on simplified bookkeeping or turnover is sometimes perceived as too complex for microenterprises in countries with high illiteracy levels. Very simple fixed tax regimes not requiring any book...

  11. Flux scaling: Ultimate regime

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Flux scaling: Ultimate regime. With the Nusselt number and the mixing length scales, we get the Nusselt number and Reynolds number (w'd/ν) scalings: and or. and. scaling expected to occur at extremely high Ra Rayleigh-Benard convection. Get the ultimate regime ...

  12. Measuring autocratic regime stability

    Directory of Open Access Journals (Sweden)

    Joseph Wright

    2016-01-01

    Full Text Available Researchers measure regime stability in autocratic contexts using a variety of data sources that capture distinct concepts. Often this research uses concepts developed for the study of democratic politics, such as leadership change or institutionalized authority, to construct measures of regime breakdown in non-democratic contexts. This article assesses whether the measure a researcher chooses influences the results they obtain by examining data on executive leadership, political authority, and autocratic regimes. We illustrate the conceptual differences between these variables by extending recent studies in the literature on the political consequences of non-tax revenue and unearned foreign income.

  13. Advantages of Unfair Quantum Ground-State Sampling.

    Science.gov (United States)

    Zhang, Brian Hu; Wagenbreth, Gene; Martin-Mayor, Victor; Hen, Itay

    2017-04-21

    The debate around the potential superiority of quantum annealers over their classical counterparts has been ongoing since the inception of the field. Recent technological breakthroughs, which have led to the manufacture of experimental prototypes of quantum annealing optimizers with sizes approaching the practical regime, have reignited this discussion. However, the demonstration of quantum annealing speedups remains to this day an elusive albeit coveted goal. We examine the power of quantum annealers to provide a different type of quantum enhancement of practical relevance, namely, their ability to serve as useful samplers from the ground-state manifolds of combinatorial optimization problems. We study, both numerically by simulating stoquastic and non-stoquastic quantum annealing processes, and experimentally, using a prototypical quantum annealing processor, the ability of quantum annealers to sample the ground-states of spin glasses differently than thermal samplers. We demonstrate that (i) quantum annealers sample the ground-state manifolds of spin glasses very differently than thermal optimizers (ii) the nature of the quantum fluctuations driving the annealing process has a decisive effect on the final distribution, and (iii) the experimental quantum annealer samples ground-state manifolds significantly differently than thermal and ideal quantum annealers. We illustrate how quantum annealers may serve as powerful tools when complementing standard sampling algorithms.

  14. Influence of curing regimes on compressive strength of ultra high ...

    Indian Academy of Sciences (India)

    The present paper is aimed to identify an efficient curing regime for ultra high performance concrete (UHPC), to achieve a target compressive strength more than 150 MPa, using indigenous materials. The thermal regime plays a vital role due to the limited fineness of ingredients and low water/binder ratio. By activation of the ...

  15. Thermal behaviour of ground vermiculite

    Czech Academy of Sciences Publication Activity Database

    Balek, Vladimír; Perez, M.; Šubrt, Jan; Poyato, J.

    2007-01-01

    Roč. 88, č. 3 (2007), s. 819-823 ISSN 1388-6150 Grant - others:GA MŠk(CZ) LA 040 Institutional research plan: CEZ:AV0Z40320502 Keywords : kaolinite * pyrophyllite * bentonite Subject RIV: CA - Inorganic Chemistry Impact factor: 1.483, year: 2007

  16. Relationships Between Canopy Openness, Snow Cover and Ground Temperature.

    Science.gov (United States)

    Mattson, L.

    2004-05-01

    Red pine stands, which have undergone varying degrees of thinning and site preparation, are examined with a view to identifying the relationships which exist between canopy openness, snow cover and ground temperature. More specifically, eight red pine stands, which have been intentionally harvested at varying densities within the National Petawawa Research Forest, have been heavily instrumented for detailed measurements of canopy openness, snow cover characteristics, above and subsurface temperature profiles as well as micro-meteorological conditions. Results allow for the specification of relationships between the effect of thinning and site preparation on the soils thermal regime which, in turn, impacts upon the natural regeneration of the pine.

  17. Designing as Middle Ground

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian; Binder, Thomas

    2010-01-01

    The theoretical background in this chapter is science and technology studies and actor network theory, enabling investigation of heterogeneity, agency and perfor-mative effects through ‘symmetric’ analysis. The concept of design is defined as being imaginative and mindful to a number of actors in...... research is an articulation of design activity taking place as a middle ground and as an intermixture between a ‘scientific’ regime of knowledge transfer and a capital ‘D’ ‘Designerly’ regime of authoring....

  18. THE INFLUENCED FLOW REGIMES

    Directory of Open Access Journals (Sweden)

    Gavril PANDI

    2011-03-01

    Full Text Available The influenced flow regimes. The presence and activities ofhumanity influences the uniform environmental system, and in this context, therivers water resources. In concordance with this, the natural runoff regime suffersbigger and deeper changes. The nature of these changes depending on the type anddegree of water uses. The multitude of the use cause different types of influence,whit different quantitative aspects. In the same time, the influences havequalitative connotations, too, regarding to the modifications of the yearly watervolume runoff. So the natural runoff regime is modified. After analyzing thedistribution laws of the monthly runoff, there have been differenced four types ofinfluenced runoff regimes. In the excess type the influenced runoff is bigger thanthe natural, continuously in the whole year. The deficient type is characterized byinverse rapports like the first type, in the whole year. In the sinusoidal type, theinfluenced runoff is smaller than the natural in the period when the water isretained in the lake reservoirs, and in the depletion period the situation inverts. Atthe irregular type the ratio between influenced and natural runoff is changeable ina random meaner monthly. The recognition of the influenced regime and the gradeof influence are necessary in the evaluation and analysis of the usable hydrologicalriver resources, in the flood defence activities, in the complex scheme of thehydrographic basins, in the environment design and so on.

  19. Arctic circulation regimes.

    Science.gov (United States)

    Proshutinsky, Andrey; Dukhovskoy, Dmitry; Timmermans, Mary-Louise; Krishfield, Richard; Bamber, Jonathan L

    2015-10-13

    Between 1948 and 1996, mean annual environmental parameters in the Arctic experienced a well-pronounced decadal variability with two basic circulation patterns: cyclonic and anticyclonic alternating at 5 to 7 year intervals. During cyclonic regimes, low sea-level atmospheric pressure (SLP) dominated over the Arctic Ocean driving sea ice and the upper ocean counterclockwise; the Arctic atmosphere was relatively warm and humid, and freshwater flux from the Arctic Ocean towards the subarctic seas was intensified. By contrast, during anticylonic circulation regimes, high SLP dominated driving sea ice and the upper ocean clockwise. Meanwhile, the atmosphere was cold and dry and the freshwater flux from the Arctic to the subarctic seas was reduced. Since 1997, however, the Arctic system has been under the influence of an anticyclonic circulation regime (17 years) with a set of environmental parameters that are atypical for this regime. We discuss a hypothesis explaining the causes and mechanisms regulating the intensity and duration of Arctic circulation regimes, and speculate how changes in freshwater fluxes from the Arctic Ocean and Greenland impact environmental conditions and interrupt their decadal variability. © 2015 The Authors.

  20. Transition to ballistic regime for heat transport in helium II

    Energy Technology Data Exchange (ETDEWEB)

    Sciacca, Michele, E-mail: michele.sciacca@unipa.it [Dipartimento Scienze Agrarie e Forestali, Università degli studi di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Sellitto, Antonio, E-mail: ant.sellitto@gmail.com [Dipartimento di Matematica, Informatica ed Economia, Università della Basilicata, Campus Macchia Romana, 85100 Potenza (Italy); Jou, David, E-mail: david.jou@uab.cat [Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Institut d' Estudis Catalans, Carme 47, 08001 Barcelona, Catalonia (Spain)

    2014-07-04

    The size-dependent and flux-dependent effective thermal conductivity of narrow capillaries filled with superfluid helium is analyzed from a thermodynamic continuum perspective. The classical Landau evaluation of the effective thermal conductivity of quiescent superfluid, or the Gorter–Mellinck regime of turbulent superfluids, is extended to describe the transition to ballistic regime in narrow channels wherein the radius R is comparable to (or smaller than) the phonon mean-free path ℓ in superfluid helium. To do so, we start from an extended equation for the heat flux incorporating non-local terms, and take into consideration a heat slip flow along the walls of the tube. This leads from an effective thermal conductivity proportional to R{sup 2} (Landau regime) to another one proportional to Rℓ (ballistic regime). We consider two kinds of flows: along cylindrical pipes and along two infinite parallel plates. - Highlights: • Heat transport in counterflow helium in the ballistic regime. • The one-fluid model based on the Extended Thermodynamics is used. • The transition from the Landau regime to the ballistic regime. • The transition from quantum turbulence to ballistic regime.

  1. Solar–terrestrial radiant-energy regimes and temperature anomalies of natural and artificial turfs

    International Nuclear Information System (INIS)

    Jim, C.Y.

    2016-01-01

    Highlights: • Solar and terrestrial radian energy regimes affect temperature response of sports turfs. • Adjacent natural and artificial turfs were monitored with replications on sunny days. • Artificial turf has meager albedo, low specific heat and moisture to augment warming. • Artificial turf surface and substrate reach 70 °C but cool down effectively at night. • Artificial turf may induce heat stress on athletes in hot summer afternoon. - Abstract: Artificial turf can develop unusually high surface temperature on hot sunny days. Solar and terrestrial radiant energy regimes as key determinants of thermal performance deserve detailed investigation. This study evaluated six components of the radiant-energy environment of a natural turf (NT) and a contiguous artificial turf (AT) sports fields in Hong Kong: direct solar, reflected solar, net solar, sky thermal, ground thermal, and net thermal. Temperature was monitored at five positions: air at 150 cm, 50 cm and 15 cm height, turf surface, and substrate. The experiment included four replications, namely two summer sunny days, and two duplicated instrument sets at each turf site. The two sites reacted very differently to the same intense daily sum of solar radiation input of 23.70 MW m −2 with 9 h of bright sunshine (>120 W m −2 ), and daily sum of sky thermal radiation input of 38.59 MW m −2 . The maximum direct solar radiation reached 976.1 W m −2 at 1245 h. NT albedo of 0.23 vis-à-vis AT of merely 0.073, and higher moisture content and specific heat of NT materials, presented critical differences. The hydrophobic and generally dry plastic (polyethylene) pile-fibers and black rubber-granule infill materials have low specific heat. Intense incoming shortwave and longwave radiation absorbed readily by AT materials raised turf surface temperature to 70.2 °C and substrate 69.3 °C, in comparison with <40 °C at NT. A cascading warming effect was triggered, beginning with low albedo, high net solar

  2. East Asian welfare regime

    DEFF Research Database (Denmark)

    Abrahamson, Peter

    2017-01-01

    The paper asks if East Asian welfare regimes are still productivist and Confucian? And, have they developed public care policies? The literature is split on the first question but (mostly) confirmative on the second. Care has to a large, but insufficient extent, been rolled out in the region...

  3. Understanding regime shifts

    DEFF Research Database (Denmark)

    Heymann, Matthias; Nielsen, Kristian Hvidtfelt

    ”. Danish wind power development is all the more surprising, as the innovation process in wind technology was carried to a large extent by non-academic craftsmen and political activists. Many features of this innovation story have been investigated and that research makes it possible to summarize...... the current understanding of the regime shift....

  4. Supply regimes in fisheries

    DEFF Research Database (Denmark)

    Nielsen, Max

    2006-01-01

    Supply in fisheries is traditionally known for its backward bending nature, owing to externalities in production. Such a supply regime, however, exist only for pure open access fisheries. Since most fisheries worldwide are neither pure open access, nor optimally managed, rather between the extrem...

  5. Interannual changes in snow cover and its impact on ground surface temperatures in Livingston Island (Antarctica)

    Science.gov (United States)

    Nieuwendam, Alexandre; Ramos, Miguel; Vieira, Gonçalo

    2015-04-01

    In permafrost areas the seasonal snow cover is an important factor on the ground thermal regime. Snow depth and timing are important in ground insulation from the atmosphere, creating different snow patterns and resulting in spatially variable ground temperatures. The aim of this work is to characterize the interactions between ground thermal regimes and snow cover and the influence on permafrost spatial distribution. The study area is the ice-free terrains of northwestern Hurd Peninsula in the vicinity of the Spanish Antarctic Station "Juan Carlos I" and Bulgarian Antarctic Station "St. Kliment Ohridski". Air and ground temperatures and snow thickness data where analysed from 4 sites along an altitudinal transect in Hurd Peninsula from 2007 to 2012: Nuevo Incinerador (25 m asl), Collado Ramos (110 m), Ohridski (140 m) and Reina Sofia Peak (275 m). The data covers 6 cold seasons showing different conditions: i) very cold with thin snow cover; ii) cold with a gradual increase of snow cover; iii) warm with thick snow cover. The data shows three types of periods regarding the ground surface thermal regime and the thickness of snow cover: a) thin snow cover and short-term fluctuation of ground temperatures; b) thick snow cover and stable ground temperatures; c) very thick snow cover and ground temperatures nearly constant at 0°C. a) Thin snow cover periods: Collado Ramos and Ohridski sites show frequent temperature variations, alternating between short-term fluctuations and stable ground temperatures. Nuevo Incinerador displays during most of the winter stable ground temperatures; b) Cold winters with a gradual increase of the snow cover: Nuevo Incinerador, Collado Ramos and Ohridski sites show similar behavior, with a long period of stable ground temperatures; c) Thick snow cover periods: Collado Ramos and Ohridski show long periods of stable ground, while Nuevo Incinerador shows temperatures close to 0°C since the beginning of the winter, due to early snow cover

  6. Spatial and temporal variation of water temperature regimes on the Snoqualmie River network

    Science.gov (United States)

    Ashley E. Steel; Colin Sowder; Erin E. Peterson

    2016-01-01

    Although mean temperatures change annually and are highly correlated with elevation, the entire thermal regime on the Snoqualmie River, Washington, USA does not simply shift with elevation or season. Particular facets of the thermal regime have unique spatial patterns on the river network and at particular times of the year. We used a spatially and temporally dense...

  7. MODELING COMBINING TAX REGIMES

    Directory of Open Access Journals (Sweden)

    Prishchenko E. A.

    2016-03-01

    Full Text Available The article discusses the combination of tax regimes as a result of separation from the operating business of the revenues and costs for system of a united tax on imputed income (UTII with the analysis of the tax consequences of such allocation. Three models of taxation were built: both variants of the simplified system of taxation from UTII and common system of taxation with UTII. We propose a rapid method of the most preferred system of taxation for small businesses’ selection depending material to labor costs ratio. All these results could be implemented in the case when the company starts a new type of activity under the rules UTII, and solves the problem in the framework of the tax regime to conduct this activity - UTII applied or not, based on the criterion of tax savings. Using the relations describing the tax burden when combined tax regimes, we can determine what the yield should have a new business line and what cost structure should it have to reduce the tax burden. The main result is proposed approach that can be used as a tool of tax planning activities of small businesses.

  8. Thermal tolerance of O157 and non-O157 Shiga toxigenic strains of Escherichia coli, Salmonella, and potential pathogen surrogates, in frankfurter batter and ground beef of varying fat levels.

    Science.gov (United States)

    Vasan, Akhila; Geier, Renae; Ingham, Steve C; Ingham, Barbara H

    2014-09-01

    The non-O157 Shiga toxigenic Escherichia coli (STEC) serogroups most commonly associated with illness are O26, O45, O103, O111, O121, and O145. We compared the thermal tolerance (D55°C) of three or more strains of each of these six non-O157 STEC serogroups with five strains of O157:H7 STEC in 7% fat ground beef. D55°C was also determined for at least one heat-tolerant STEC strain per serogroup in 15 and 27% fat ground beef. D55°C of single-pathogen cocktails of O157 and non-O157 STEC, Salmonella, and potential pathogen surrogates, Pediococcus acidilactici and Staphylococcus carnosus, was determined in 7, 15, and 27% fat ground beef and in frankfurter batter. Samples (25 g) were heated for up to 120 min at 55°C, survivors were enumerated, and log CFU per gram was plotted versus time. There were significant differences in D55°C across all STEC strains heated in 7% fat ground beef (P batter was significantly less than for O157 and non-O157 STEC (P batter was significantly less than for potential pathogen surrogates (P batter would be of limited utility to processors.

  9. A new tool for prediction and analysis of thermal comfort in steady and transient states; Un nouvel outil pour la prediction et l'analyse du confort thermique en regime permanent et variable

    Energy Technology Data Exchange (ETDEWEB)

    Megri, A.Ch. [Illinois Institute of Technology, Civil and Architectural Engineering Dept., Chicago, Illinois (United States); Megri, A.F. [Centre Universitaire de Tebessa, Dept. d' Electronique (Algeria); El Naqa, I. [Washington Univ., School of Medicine, Dept. of Radiation Oncology, Saint Louis, Missouri (United States); Achard, G. [Universite de Savoie, Lab. Optimisation de la Conception et Ingenierie de L' Environnement (LOCIE) - ESIGEC, 73 - Le Bourget du Lac (France)

    2006-02-15

    Thermal comfort is influenced by psychological as well as physiological factors. This paper proposes the use of support vector machine (SVM) learning for automated prediction of human thermal comfort in steady and transient states. The SVM is an artificial intelligent approach that could capture the input/output mapping from the given data. Support vector machines were developed based on the Structural Risk Minimization principle. Different sets of representative experimental environmental factors that affect a homogenous person's thermal balance were used for training the SVM machine. The SVM is a very efficient, fast, and accurate technique to identify thermal comfort. This technique permits the determination of thermal comfort indices for different sub-categories of people; sick and elderly, in extreme climatic conditions, when the experimental data for such sub-category are available. The experimental data has been used for the learning and testing processes. The results show a good correlation between SVM predicted values and those obtained from conventional thermal comfort, such as Fanger and Gagge models. The 'trained machine' with representative data could be used easily and effectively in comparison with other conventional estimation methods of different indices. (author)

  10. Ground-based thermography of fluvial systems at low and high discharge reveals potential complex thermal heterogeneity driven by flow variation and bioroughness

    Science.gov (United States)

    Cardenas, M.B.; Harvey, J.W.; Packman, A.I.; Scott, D.T.

    2008-01-01

    Temperature is a primary physical and biogeochemical variable in aquatic systems. Field-based measurement of temperature at discrete sampling points has revealed temperature variability in fluvial systems, but traditional techniques do not readily allow for synoptic sampling schemes that can address temperature-related questions with broad, yet detailed, coverage. We present results of thermal infrared imaging at different stream discharge (base flow and peak flood) conditions using a handheld IR camera. Remotely sensed temperatures compare well with those measured with a digital thermometer. The thermal images show that periphyton, wood, and sandbars induce significant thermal heterogeneity during low stages. Moreover, the images indicate temperature variability within the periphyton community and within the partially submerged bars. The thermal heterogeneity was diminished during flood inundation, when the areas of more slowly moving water to the side of the stream differed in their temperature. The results have consequences for thermally sensitive hydroelogical processes and implications for models of those processes, especially those that assume an effective stream temperature. Copyright ?? 2008 John Wiley & Sons, Ltd.

  11. Transient response of Salix cuttings to changing water level regimes

    Science.gov (United States)

    Gorla, L.; Signarbieux, C.; Turberg, P.; Buttler, A.; Perona, P.

    2015-03-01

    Sustainable water management requires an understanding of the effects of flow regulation on riparian ecomorphological processes. We investigated the transient response of Salix viminalis by examining the effect of water-level regimes on its above-ground and below-ground biomass. Four sets of Salix cuttings, three juveniles (in the first growing season) and one mature (1 year old), were planted and initially grown under the same water-level regime for 1 month. We imposed three different water-level regime treatments representing natural variability, a seasonal trend with no peaks, and minimal flow (characteristic of hydropower) consisting of a constant water level and natural flood peaks. We measured sap flux, stem water potential, photosynthesis, growth parameters, and final root architecture. The mature cuttings were not affected by water table dynamics, but the juveniles displayed causal relationships between the changing water regime, plant growth, and root distribution during a 2 month transient period. For example, a 50% drop in mean sap flux corresponded with a -1.5 Mpa decrease in leaf water potential during the first day after the water regime was changed. In agreement with published field observations, the cuttings concentrated their roots close to the mean water table of the corresponding treatment, allowing survival under altered conditions and resilience to successive stress events. Juvenile development was strongly impacted by the minimum flow regime, leading to more than 60% reduction of both above-ground and below-ground biomass, with respect to the other treatments. Hence, we suggest avoiding minimum flow regimes where Salix restoration is prioritized.

  12. Ground ULV and thermal fog applications against Phlebotomine sand fly vectors of Leishmania in a hot arid environment in western Kenya

    Science.gov (United States)

    Phlebotomine sand fly vectors of Leishmania continue to threaten US military operations in Africa, Southwest Asia, and the Middle East. Ultra-low volume (ULV) and/or thermal fog pesticide dispersal are potentially effective against sand flies, but operational guidance is thinly based on mosquito con...

  13. More with thermal energy storage. Report 8. Autonomous heating. Autonomous development of ground temperature. Final report; Meer met bodemenergie. Rapport 8. Autonome opwarming. Autonome ontwikkeling bodemtemperatuur. Eindrapport

    Energy Technology Data Exchange (ETDEWEB)

    Drijver, B. [IF Technology, Arnhem (Netherlands)

    2012-03-30

    The project More With Thermal Energy Storage (MMB, abbreviated in Dutch) focuses on knowledge gaps and potential opportunities regarding open systems. The main questions to be answered are: (1) What effects (hydrological, thermal, microbiological and chemical) occur in the soil system by application of thermal energy storage; (2) Which technical options are available for a sustainable integration of thermal energy storage in the water and energy chain?; (3) Is it possible to achieve multiple objectives by using smart combinations? The project is organized in different work packages. In work package 2, the effects of individual and collective thermal energy storage storage systems on subsoils and the environment are determined. In work package 3 the opportunities for thermal energy storage and soil remediation are examined, while in work package 4 the focus is on new sustainable combinations of heat and cold storage. Work package 1 is the umbrella part where communication and policy of and participation in MMB are the main subjects. This report contains an analysis of the thermal impact of climate change and urbanization on the soil temperature. Attention is paid to the autonomous heating of the subsurface that occurred since 1900 and that still may be expected up to 2040. A distinction is made between rural areas, where only the climate change plays a role, and urban areas, where the UHI effect (Urban Heat Island) is of importance [Dutch] Het project Meer Met Bodemenergie (MMB) richt zich op het invullen van kennisleemtes en mogelijke kansen ten aanzien van open systemen. De belangrijkste vragen waarop het onderzoeksprogramma MMB antwoord geeft zijn: (1) Welke effecten (hydrologisch, thermisch, microbiologisch en chemisch) treden op in het bodemsysteem bij toepassing van bodemenergie?; (2) Welke technische mogelijkheden zijn er voor het duurzaam inpassen van bodem-energie in de water- en energieketen?; (3) Is het mogelijk om meerdere doelstellingen tegelijk te

  14. Magma extrusion during the Ubinas 2013-2014 eruptive crisis based on satellite thermal imaging (MIROVA) and ground-based monitoring

    Science.gov (United States)

    Coppola, Diego; Macedo, Orlando; Ramos, Domingo; Finizola, Anthony; Delle Donne, Dario; del Carpio, José; White, Randall; McCausland, Wendy; Centeno, Riky; Rivera, Marco; Apaza, Fredy; Ccallata, Beto; Chilo, Wilmer; Cigolini, Corrado; Laiolo, Marco; Lazarte, Ivonne; Machaca, Roger; Masias, Pablo; Ortega, Mayra; Puma, Nino; Taipe, Edú

    2015-09-01

    After 3 years of mild gases emissions, the Ubinas volcano entered in a new eruptive phase on September 2nd, 2013. The MIROVA system (a space-based volcanic hot-spot detection system), allowed us to detect in near real time the thermal emissions associated with the eruption and provided early evidence of magma extrusion within the deep summit crater. By combining IR data with plume height, sulfur emissions, hot spring temperatures and seismic activity, we interpret the thermal output detected over Ubinas in terms of extrusion rates associated to the eruption. We suggest that the 2013-2014 eruptive crisis can be subdivided into three main phases: (i) shallow magma intrusion inside the edifice, (ii) extrusion and growing of a lava plug at the bottom of the summit crater coupled with increasing explosive activity and finally, (iii) disruption of the lava plug and gradual decline of the explosive activity. The occurrence of the 8.2 Mw Iquique (Chile) earthquake (365 km away from Ubinas) on April 1st, 2014, may have perturbed most of the analyzed parameters, suggesting a prompt interaction with the ongoing volcanic activity. In particular, the analysis of thermal and seismic datasets shows that the earthquake may have promoted the most intense thermal and explosive phase that culminated in a major explosion on April 19th, 2014. These results reveal the efficiency of space-based thermal observations in detecting the extrusion of hot magma within deep volcanic craters and in tracking its evolution. We emphasize that, in combination with other geophysical and geochemical datasets, MIROVA is an essential tool for monitoring remote volcanoes with rather difficult accessibility, like those of the Andes that reach remarkably high altitudes.

  15. Magma extrusion during the Ubinas 2013–2014 eruptive crisis based on satellite thermal imaging (MIROVA) and ground-based monitoring

    Science.gov (United States)

    Coppola, Diego; Macedo, Orlando; Ramos, Domingo; Finizola, Anthony; Delle Donne, Dario; del Carpio, Jose; White, Randall A.; McCausland, Wendy; Centeno, Riky; Rivera, Marco; Apaza, Fredy; Ccallata, Beto; Chilo, Wilmer; Cigolini, Corrado; Laiolo, Marco; Lazarte, Ivonne; Machaca, Roger; Masias, Pablo; Ortega, Mayra; Puma, Nino; Taipe, Edú

    2015-01-01

    After 3 years of mild gases emissions, the Ubinas volcano entered in a new eruptive phase on September 2nd, 2013. The MIROVA system (a space-based volcanic hot-spot detection system), allowed us to detect in near real time the thermal emissions associated with the eruption and provided early evidence of magma extrusion within the deep summit crater. By combining IR data with plume height, sulfur emissions, hot spring temperatures and seismic activity, we interpret the thermal output detected over Ubinas in terms of extrusion rates associated to the eruption. We suggest that the 2013–2014 eruptive crisis can be subdivided into three main phases: (i) shallow magma intrusion inside the edifice, (ii) extrusion and growing of a lava plug at the bottom of the summit crater coupled with increasing explosive activity and finally, (iii) disruption of the lava plug and gradual decline of the explosive activity. The occurrence of the 8.2 Mw Iquique (Chile) earthquake (365 km away from Ubinas) on April 1st, 2014, may have perturbed most of the analyzed parameters, suggesting a prompt interaction with the ongoing volcanic activity. In particular, the analysis of thermal and seismic datasets shows that the earthquake may have promoted the most intense thermal and explosive phase that culminated in a major explosion on April 19th, 2014.These results reveal the efficiency of space-based thermal observations in detecting the extrusion of hot magma within deep volcanic craters and in tracking its evolution. We emphasize that, in combination with other geophysical and geochemical datasets, MIROVA is an essential tool for monitoring remote volcanoes with rather difficult accessibility, like those of the Andes that reach remarkably high altitudes.

  16. Thermal Phase Transitions of Strongly Correlated Bosons with Spin-Orbit Coupling

    Science.gov (United States)

    Hickey, Ciarán; Paramekanti, Arun

    2014-12-01

    Experiments on ultracold atoms have started to explore lattice effects and thermal fluctuations for two-component bosons with spin-orbit coupling (SOC). Motivated by this, we derive and study a t J model for lattice bosons with equal Rashba-Dresselhaus SOC and strong Hubbard repulsion in a uniform Zeeman magnetic field. Using the Gutzwiller ansatz, we find strongly correlated ground states with stripe superfluid (SF) order. We formulate a finite temperature generalization of the Gutzwiller method, and show that thermal fluctuations in the doped Mott insulator drive a two-step melting of the stripe SF, revealing a wide regime of a stripe normal fluid.

  17. Shot-noise dominant regime of a nanoparticle in a laser beam

    Science.gov (United States)

    Zhong, Changchun; Robicheaux, Francis

    2017-04-01

    The technique of laser levitation of nanoparticles has become increasingly promising in the study of cooling and controlling mesoscopic quantum systems. Unlike a mechanical system, the levitated nanoparticle is less exposed to thermalization and decoherence due to the absence of direct contact with a thermal environment. In ultrahigh vacuum, the dominant source of decoherence comes from the unavoidable photon recoil from the optical trap which sets an ultimate bound for the control of levitated systems. In this paper, we study the shot noise heating and the parametric feedback cooling of an optically trapped anisotropic nanoparticle in the laser shot noise dominant regime. The rotational trapping frequency and shot noise heating rate have a dependence on the shape of the trapped particle. For an ellipsoidal particle, the ratio of the axis lengths and the overall size controls the shot noise heating rate relative to the rotational frequency. For a near spherical nanoparticle, the effective heating rate for the rotational degrees of freedom is smaller than that for translation suggesting that the librational ground state may be easier to achieve than the vibrational ground state.

  18. Software for Automated Generation of Reduced Thermal Models for Spacecraft Thermal Control, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermal analysis is increasingly used in thermal engineering of spacecrafts in every stage, including design, test, and ground-operation simulation. Current...

  19. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  20. Drilling and thermal gradient measurements at US Marine Corps Air Ground Combat Center, Twentynine Palms, California. Final report, October 1, 1983-March 31, 1984

    Energy Technology Data Exchange (ETDEWEB)

    Trexler, D.T.; Flynn, T.; Ghusn, G. Jr.

    1984-01-01

    Seven temperature gradient holes were drilled at the Marine Corps Air Ground Combat Center, Twentynine Palms, California, as part of a cooperative research and development program, jointly funded by the Navy and Department of Energy. The purpose of this program was to assess geothermal resources at selected Department of Defense installations. Drill site selection was based on geophysical anomalies delineated by combined gravity, ground magnetic and aeromagnetic surveys. Temperature gradients ranged from 1.3/sup 0/C/100 m (1/sup 0/F/100 ft.) in hole No. 1 to 15.3/sup 0/C/100 m (8.3/sup 0/F/100 ft.) in temperature gradient hole No. 6. Large, positive geothermal gradients in temperature gradient holes 5 and 6, combined with respective bottom hole temperatures of 51.6/sup 0/C (125/sup 0/F) and 67/sup 0/C (153/sup 0/F), indicate that an extensive, moderate-temperature geothermal resource is located on the MCAGCC. The geothermal reservoir appears to be situated in old, unconsolidated alluvial material and is structurally bounded on the east by the Mesquite Lake fault and on the west by the Surprise Spring fault. If measured temperature gradients continue to increase at the observed rate, temperatures in excess of 80/sup 0/C (178/sup 0/F) can be expected at a depth of 2000 feet.

  1. Análise espacial das condições térmicas do ambiente pré-ordenha de bovinos leiteiros sob regimes de climatização Spatial analysis of thermal conditions of the pre-milking dairy cattle under climatization regimes

    Directory of Open Access Journals (Sweden)

    Irenilson M. da Silva

    2012-08-01

    Full Text Available Propõe-se, com este trabalho, caracterizar a variabilidade espacial da temperatura do ar na sala de pré-ordenha a partir de diferentes tempos de operação do sistema de resfriamento adiabático evaporativo automatizado. A variável temperatura do ar foi registrada em 35 pontos equidistantes 1 m, na forma de malha, para o estudo da variabilidade espacial e a construção de mapas por krigagem. Foram considerados diferentes tempos de exposição dos animais a climatização no curral de espera, 20, 30, 40 min e controle (0 min. Por meio dos resultados obtidos foi possível verificar que o uso da geoestatística possibilitou definir áreas com diferentes variabilidades espaciais para temperatura do ar, definindo áreas específicas na sala de pré-ordenha que apresentaram valores acima do recomendado para o conforto térmico animal. O sistema de climatização garantiu melhor acondicionamento térmico no tempo de exposição de 40 min, obtendo temperatura média dentro da condição de conforto térmico para vacas em lactação.The objective of this study was to characterize the spatial variability of air temperature in pre-milking room for different operation times of the automated adiabatic evaporative cooling system. The air temperature was monitored at 35 points, in regular intervals of 1 m, as a grid, to study the spatial variability and construction of kriging maps. Different times of exposure of the animals to the cooling system in the waiting room (20, 30, 40 min and control - 0 min were considered. Through the results, it was observed that use of geostatistics enabled to define areas with different spatial variability for temperature, identifying specific areas in the pre-milking room that showed values above the recommended levels for the thermal comfort. The cooling system ensured the better thermal condition with the 40 min exposure, obtaining on average temperature within the thermal comfort condition for lactating cows.

  2. Unitary Housing Regimes in Transition

    DEFF Research Database (Denmark)

    Bengtsson, Bo; Jensen, Lotte

    2013-01-01

    to the Danish and Swedish housing regimes are analysed and the responses and outcomes in terms of policy change and/or institutional continuity (path dependence) are compared. Overall, the more decentralized Danish housing regime seems to have resisted pressures for change and retrenchment better so far than...

  3. Thermal Environmental Design in Outdoor Space Focusing on Radiation Environment Influenced by Ground Cover Material and Solar Shading, through the Examination on the Redevelopment Buildings in Front of Central Osaka Station

    Directory of Open Access Journals (Sweden)

    Hideki Takebayashi

    2018-01-01

    Full Text Available The outdoor open space is used for various purposes, e.g., to walk, rest, talk, meet, study, exercise, play, perform, eat, and drink. Therefore, it is desirable to provide various thermal environments according to users’ needs and their actual conditions. In this study, the radiation environment was evaluated, focusing on ground cover materials and solar radiation shading, through the examination on the redevelopment buildings in front of Central Osaka Station. The spatial distribution of solar radiation shading was calculated using ArcGIS and building shape data. Surface temperatures on the ground and wall are calculated based on the surface heat budget equation. MRT (Mean Radiant Temperature of the human body is calculated assuming that the human body is a sphere. The most dominant factor for the radiant environment is solar radiation shielding and the next is the improvement of surface cover. It is difficult to make SET* (Standard new Effective Temperature comfortable in the afternoon by both solar radiation shielding and improved surface cover because the air temperature is too high on a typical summer day (August. However, particularly in Rooftop Gardens and Green Garden, because the areas of shade grass and water are large, there are several places where people do not feel uncomfortable.

  4. Two-phase interfacial area and flow regime modeling in FLOWTRAN-TF code

    International Nuclear Information System (INIS)

    Smith, F.G. III; Lee, S.Y.; Flach, G.P.; Hamm, L.L.

    1992-01-01

    FLOWTRAN-TF is a new two-component, two-phase thermal-hydraulics code to capture the detailed assembly behavior associated with loss-of-coolant accident analyses in multichannel assemblies of the SRS reactors. The local interfacial area of the two-phase mixture is computed by summing the interfacial areas contributed by each of three flow regimes. For smooth flow regime transitions, the code uses an interpolation technique in terms of component void fraction for each basic flow regime

  5. Predicted median July stream/river temperature regime in New England

    Data.gov (United States)

    U.S. Environmental Protection Agency — This shapefile includes the predicted thermal regime for all NHDPlus version 1 stream and river reaches in New England within the model domain based on the spatial...

  6. Hydrological regimes in Balkan Area

    International Nuclear Information System (INIS)

    Stanescu, Viorel Alexandru

    2004-01-01

    Physical considerations of the deemed area are first considered in the paper. Then the regime types around the Balkan rivers are described in terms of the following characteristic features: -Types of the regimes defined by the timing of the high and low flow phases; -Regionalisation of the 'micro-types' -Stability of the river flow regimes. The available mean monthly discharge data of the representative rivers allows characterising the river regime of the Balkan area covered by WOISYDES and BALWOIS projects. The classification of the hydrological regimes (types of regimes) was done by assessing the discriminant periods (descriptors of the regime phases) defined by the first, the second and the third highest and lowest monthly values of flows. As sufficient data has been provided by countries involved in the Woisydes/Balwois Project a hydrological regionalisation is performed all around the considered space. The existence of different zones, which are quasi- homogeneous in terms of physiographical properties, the latter especially being expressed by their mean altitudes and the climatic features, allowed to carry out a hydrological regionalisation of the river flow regime types. The regionalisation of the river flow regimes is presented as hydrological maps both referring to each Balkan country and for the entire region as an overall map. The stability of a certain flow regime is an important descriptor of the ecological state of the river during the year. It may be quantitatively expressed by the stability coefficient determined by Corbus and Stanescu as the product between the frequency of the occurrence of any discriminant value in m subsequent month (m = 1,12) and a distribution coefficient along the period that depend on the length of the considered discriminant period. The advantage of this method stands in the fact that for several combinations of subsequent months, the maximisation of the stability coefficient leads to the assessment of the characteristic

  7. Assessment of extreme hydrological conditions in the Bothnian Bay, Baltic Sea, and the impact of the nuclear power plant ''Hanhikivi-1'' on the local thermal regime

    Energy Technology Data Exchange (ETDEWEB)

    Dvornikov, Anton Y.; Martyanov, Stanislav D.; Ryabchenko, Vladimir A.; Isaev, Alexey V. [Russian Academy of Sciences, St. Petersburg (Russian Federation). P.P. Shirshov Inst. of Oceanology; Eremina, Tatjana R. [Russian State Hydrometeorological Univ., St. Petersburg (Russian Federation); Sein, Dmitry V. [Helmholtz Centre for Polar and Marine Research, Bremerhaven (Germany). Alfred Wegener Inst.

    2017-07-01

    The results of the study aimed to assess the influence of future nuclear power plant ''Hanhikivi-1'' upon the local thermal conditions in the Bothnian Bay in the Baltic Sea are presented. A number of experiments with different numerical models were also carried out in order to estimate the extreme hydro-meteorological conditions in the area of the construction. The numerical experiments were fulfilled both with analytically specified external forcing and with real external forcing for 2 years: a cold year (2010) and a warm year (2014). The study has shown that the extreme values of sea level and water temperature and the characteristics of wind waves and sea ice in the vicinity of the future nuclear power plant can be significant and sometimes catastrophic. Permanent release of heat into the marine environment from an operating nuclear power plant will lead to a strong increase in temperature and the disappearance of ice cover within a 2 km vicinity of the station. These effects should be taken into account when assessing local climate changes in the future.

  8. Optical and Hall conductivities of a thermally disordered two-dimensional spin-density wave: two-particle response in the pseudogap regime of electron-doped high-Tc superconductors

    International Nuclear Information System (INIS)

    Lin, J.; Millis, A.J.

    2011-01-01

    We calculate the frequency-dependent longitudinal (σ xx ) and Hall (σ xy ) conductivities for two-dimensional metals with thermally disordered antiferromagnetism using a generalization of a theoretical model, involving a one-loop quasistatic fluctuation approximation, which was previously used to calculate the electron self-energy. The conductivities are calculated from the Kubo formula, with current vertex function treated in a conserving approximation satisfying the Ward identity. In order to obtain a finite dc limit, we introduce phenomenologically impurity scattering, characterized by a relaxation time τ. σ xx ((Omega)) satisfies the f-sum rule. For the infinitely peaked spin-correlation function, χ(q)∝(delta)(q-Q), we recover the expressions for the conductivities in the mean-field theory of the ordered state. When the spin-correlation length ζ is large but finite, both σ xx and σ xy show behaviors characteristic of the state with long-range order. The calculation runs into difficulty for (Omega) ∼ xx ((Omega)) and σ xy ((Omega)) are qualitatively consistent with data on electron-doped cuprates when (Omega) > 1/τ.

  9. Ground surface temperature and continental heat gain: uncertainties from underground

    International Nuclear Information System (INIS)

    Beltrami, Hugo; Matharoo, Gurpreet S; Smerdon, Jason E

    2015-01-01

    Temperature changes at the Earth's surface propagate and are recorded underground as perturbations to the equilibrium thermal regime associated with the heat flow from the Earth's interior. Borehole climatology is concerned with the analysis and interpretation of these downward propagating subsurface temperature anomalies in terms of surface climate. Proper determination of the steady-state geothermal regime is therefore crucial because it is the reference against which climate-induced subsurface temperature anomalies are estimated. Here, we examine the effects of data noise on the determination of the steady-state geothermal regime of the subsurface and the subsequent impact on estimates of ground surface temperature (GST) history and heat gain. We carry out a series of Monte Carlo experiments using 1000 Gaussian noise realizations and depth sections of 100 and 200 m as for steady-state estimates depth intervals, as well as a range of data sampling intervals from 10 m to 0.02 m. Results indicate that typical uncertainties for 50 year averages are on the order of ±0.02 K for the most recent 100 year period. These uncertainties grow with decreasing sampling intervals, reaching about ±0.1 K for a 10 m sampling interval under identical conditions and target period. Uncertainties increase for progressively older periods, reaching ±0.3 K at 500 years before present for a 10 m sampling interval. The uncertainties in reconstructed GST histories for the Northern Hemisphere for the most recent 50 year period can reach a maximum of ±0.5 K in some areas. We suggest that continuous logging should be the preferred approach when measuring geothermal data for climate reconstructions, and that for those using the International Heat Flow Commission database for borehole climatology, the steady-state thermal conditions should be estimated from boreholes as deep as possible and using a large fitting depth range (∼100 m). (letter)

  10. Ground Wars

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Kleis

    Political campaigns today are won or lost in the so-called ground war--the strategic deployment of teams of staffers, volunteers, and paid part-timers who work the phones and canvass block by block, house by house, voter by voter. Ground Wars provides an in-depth ethnographic portrait of two...... such campaigns, New Jersey Democrat Linda Stender's and that of Democratic Congressman Jim Himes of Connecticut, who both ran for Congress in 2008. Rasmus Kleis Nielsen examines how American political operatives use "personalized political communication" to engage with the electorate, and weighs the implications...... of ground war tactics for how we understand political campaigns and what it means to participate in them. He shows how ground wars are waged using resources well beyond those of a given candidate and their staff. These include allied interest groups and civic associations, party-provided technical...

  11. Impacts of microtopographic snow redistribution and lateral subsurface processes on hydrologic and thermal states in an Arctic polygonal ground ecosystem: a case study using ELM-3D v1.0

    Directory of Open Access Journals (Sweden)

    G. Bisht

    2018-01-01

    Full Text Available Microtopographic features, such as polygonal ground, are characteristic sources of landscape heterogeneity in the Alaskan Arctic coastal plain. Here, we analyze the effects of snow redistribution (SR and lateral subsurface processes on hydrologic and thermal states at a polygonal tundra site near Barrow, Alaska. We extended the land model integrated in the E3SM to redistribute incoming snow by accounting for microtopography and incorporated subsurface lateral transport of water and energy (ELM-3D v1.0. Multiple 10-year-long simulations were performed for a transect across a polygonal tundra landscape at the Barrow Environmental Observatory in Alaska to isolate the impact of SR and subsurface process representation. When SR was included, model predictions better agreed (higher R2, lower bias and RMSE with observed differences in snow depth between polygonal rims and centers. The model was also able to accurately reproduce observed soil temperature vertical profiles in the polygon rims and centers (overall bias, RMSE, and R2 of 0.59 °C, 1.82 °C, and 0.99, respectively. The spatial heterogeneity of snow depth during the winter due to SR generated surface soil temperature heterogeneity that propagated in depth and time and led to ∼ 10 cm shallower and  ∼ 5 cm deeper maximum annual thaw depths under the polygon rims and centers, respectively. Additionally, SR led to spatial heterogeneity in surface energy fluxes and soil moisture during the summer. Excluding lateral subsurface hydrologic and thermal processes led to small effects on mean states but an overestimation of spatial variability in soil moisture and soil temperature as subsurface liquid pressure and thermal gradients were artificially prevented from spatially dissipating over time. The effect of lateral subsurface processes on maximum thaw depths was modest, with mean absolute differences of ∼ 3 cm. Our integration of three-dimensional subsurface hydrologic and

  12. Impacts of microtopographic snow redistribution and lateral subsurface processes on hydrologic and thermal states in an Arctic polygonal ground ecosystem: a case study using ELM-3D v1.0

    Science.gov (United States)

    Bisht, Gautam; Riley, William J.; Wainwright, Haruko M.; Dafflon, Baptiste; Yuan, Fengming; Romanovsky, Vladimir E.

    2018-01-01

    Microtopographic features, such as polygonal ground, are characteristic sources of landscape heterogeneity in the Alaskan Arctic coastal plain. Here, we analyze the effects of snow redistribution (SR) and lateral subsurface processes on hydrologic and thermal states at a polygonal tundra site near Barrow, Alaska. We extended the land model integrated in the E3SM to redistribute incoming snow by accounting for microtopography and incorporated subsurface lateral transport of water and energy (ELM-3D v1.0). Multiple 10-year-long simulations were performed for a transect across a polygonal tundra landscape at the Barrow Environmental Observatory in Alaska to isolate the impact of SR and subsurface process representation. When SR was included, model predictions better agreed (higher R2, lower bias and RMSE) with observed differences in snow depth between polygonal rims and centers. The model was also able to accurately reproduce observed soil temperature vertical profiles in the polygon rims and centers (overall bias, RMSE, and R2 of 0.59 °C, 1.82 °C, and 0.99, respectively). The spatial heterogeneity of snow depth during the winter due to SR generated surface soil temperature heterogeneity that propagated in depth and time and led to ˜ 10 cm shallower and ˜ 5 cm deeper maximum annual thaw depths under the polygon rims and centers, respectively. Additionally, SR led to spatial heterogeneity in surface energy fluxes and soil moisture during the summer. Excluding lateral subsurface hydrologic and thermal processes led to small effects on mean states but an overestimation of spatial variability in soil moisture and soil temperature as subsurface liquid pressure and thermal gradients were artificially prevented from spatially dissipating over time. The effect of lateral subsurface processes on maximum thaw depths was modest, with mean absolute differences of ˜ 3 cm. Our integration of three-dimensional subsurface hydrologic and thermal subsurface dynamics in the E3SM

  13. Endogenous Monetary Policy Regime Change

    OpenAIRE

    Troy Davig; Eric M. Leeper

    2006-01-01

    This paper makes changes in monetary policy rules (or regimes) endogenous. Changes are triggered when certain endogenous variables cross specified thresholds. Rational expectations equilibria are examined in three models of threshold switching to illustrate that (i) expectations formation effects generated by the possibility of regime change can be quantitatively important; (ii) symmetric shocks can have asymmetric effects; (iii) endogenous switching is a natural way to formally model preempt...

  14. Avaliação do conforto térmico e desempenho de frangos de corte sob regime de criação diferenciado Evaluation of thermal comfort and performance of broiler chickens under different housing systems

    Directory of Open Access Journals (Sweden)

    Aérica C. Nazareno

    2009-12-01

    Full Text Available Esta pesquisa foi conduzida com o objetivo de avaliar três sistemas de criação para frangos de corte industrial, visando caracterizar o ambiente térmico e o desempenho animal. O experimento foi realizado no decorrer de 42 dias, desenvolvido em módulos de produção, divididos em 15 boxes com 10 aves por box, submetidas a três sistemas de criação: semi-confinado com 3 m² por ave de área de piquete (SC 3, semi-confinado com 6 m² por ave de área de piquete (SC 6 e confinamento total (CONF. O delineamento experimental foi inteiramente casualizado (DIC em parcelas subdivididas e médias comparadas pelo teste Tukey (P This research was conducted to evaluate three housing systems for broiler chicken production, aiming to characterize thermal environment and animal performance. The experiment was conducted over 42 days, developed in production modules, divided in 15 boxes with 10 birds per box, and submitted to three housing systems: semi-confined with 3 m² per broiler of paddock area (SC 3, semi-confined with 6 m² per broiler of paddock area (SC 6 and total confinement (CONF. The experimental design was completely randomized (CRD, in split plots, with the means compared through the Tukey test (p < 0.05. The meteorological variables and comfort indices indicated the system of accommodation SC 3 as the one that allowed the better natural conditioning heat to the birds, presenting the average values of 25.4 °C, 69.9 kJ kg-1 and 75.7 for dry bulb temperature (Tbs, enthalpy (h and black globe humidity index (ITGU, respectively. Physiological parameters respiratory rate (mov min-1 and cloacal temperature (°C had mean values more appropriate to birds subjected to the accommodation system SC 3. The housing systems promote significant changes in performance of broiler chicken in relation to feed consumption (CR and body weight (PC in housing systems SC 3 and CONF, compared with SC 6, which presented performance losses.

  15. An observational 71-year history of seasonally frozen ground changes in the Eurasian high latitudes

    International Nuclear Information System (INIS)

    Frauenfeld, Oliver W; Zhang Tingjun

    2011-01-01

    In recent decades, significant changes have occurred in high-latitude areas, particularly to the cryosphere. Sea ice extent and thickness have declined. In land areas, glaciers and ice sheets are experiencing negative mass balance changes, and there is substantial regional snow cover variability. Subsurface changes are also occurring in northern soils. This study focuses on these changes in the soil thermal regime, specifically the seasonally frozen ground region of Eurasia. We use a database of soil temperatures at 423 stations and estimate the maximum annual soil freezing depth at the 387 sites located on seasonally frozen ground. Evaluating seasonal freeze depth at these sites for 1930–2000 reveals a statistically significant trend of −4.5 cm/decade and a net change of −31.9 cm. Interdecadal variability is also evident such that there was no trend until the late 1960s, after which seasonal freeze depths decreased significantly until the early 1990s. From that point forward, likely through at least 2008, no change is evident. These changes in the soil thermal regime are most closely linked with the freezing index, but also mean annual air temperatures and snow depth. Antecedent conditions from the previous warm season do not appear to play a large role in affecting the subsequent cold season’s seasonal freeze depths. The strong decrease in seasonal freeze depths during the 1970s to 1990s was likely the result of strong atmospheric forcing from the North Atlantic Oscillation during that time period.

  16. Transition from weak wave turbulence regime to solitonic regime

    Science.gov (United States)

    Hassani, Roumaissa; Mordant, Nicolas

    2017-11-01

    The Weak Turbulence Theory (WTT) is a statistical theory describing the interaction of a large ensemble of random waves characterized by very different length scales. For both weak non-linearity and weak dispersion a different regime is predicted where solitons propagate while keeping their shape unchanged. The question under investigation here is which regime between weak turbulence or soliton gas does the system choose ? We report an experimental investigation of wave turbulence at the surface of finite depth water in the gravity-capillary range. We tune the wave dispersion and the level of nonlinearity by modifying the depth of water and the forcing respectively. We use space-time resolved profilometry to reconstruct the deformed surface of water. When decreasing the water depth, we observe a drastic transition between weak turbulence at the weakest forcing and a solitonic regime at stronger forcing. We characterize the transition between both states by studying their Fourier Spectra. We also study the efficiency of energy transfer in the weak turbulence regime. We report a loss of efficiency of angular transfer as the dispersion of the wave is reduced until the system bifurcates into the solitonic regime. This project has recieved funding from the European Research Council (ERC, Grant Agreement No. 647018-WATU).

  17. Transport in the quantum critical regime

    Science.gov (United States)

    Enss, Tilman

    2014-05-01

    In this talk I will explain the relevance of the quantum critical point for the phase diagram of the unitary Fermi gas, briefly review theoretical approaches, and present results for the shear viscosity and spin diffusion in strongly interacting Fermi gases. The unitary Fermi gas describes strongly interacting fermions ranging from ultracold atoms near a Feshbach resonance to dilute neutron matter, which share a common universal phase diagram. The behavior at finite temperature is governed by a quantum critical point (QCP) at zero temperature and zero density, and observables can be expressed by universal scaling functions of the distance from the critical point. In the quantum critical regime above the QCP, thermal and quantum fluctuations are equally important, and the absence of a small parameter makes the computation of critical properties demanding. I will mention two theoretical approaches to transport properties in this regime: the large-N expansion in the number of fermion flavors allows for a systematic and controlled expansion even at strong coupling and elucidates the importance of medium effects on scattering. Second, the Luttinger-Ward, or self-consistent T-matrix approach goes beyond the quasiparticle picture and also explains universal high-energy tails. I will present results on the shear viscosity, or internal friction, for mass transport and show that the strongly interacting Fermi gas is an almost perfect quantum fluid. On the other hand, if particles of different spin move in opposite directions, the dynamics are governed by spin diffusion. One can distinguish longitudinal diffusion, when atomic clouds of different spin collide, and transverse diffusion, when the magnetization is wound up in a helix in a spin-echo experiment. Medium scattering and spin rotation have a strong effect on spin diffusion, and I will discuss how spin transport becomes very slow at strong coupling in the quantum degenerate regime and reaches a quantum limit of

  18. Experimental determination of thermal conductivity of soil with a thermal response test

    Directory of Open Access Journals (Sweden)

    Banjac Miloš J.

    2012-01-01

    Full Text Available Optimal design of a borehole heat exchanger, as the outer part of a ground source heat pump heating system, requires information on the thermal properties of the soil. Those data, the effective thermal conductivity of the soil λeff and the average temperature of the soil T0, enable us to determine the necessary number and depth of boreholes. The determination of thermal conductivity of the soil in laboratory experiments does not usually coincide with the data under in-situ conditions. Therefore, an in-situ method of experimental determination of these parameters, the so-called thermal response test, is presented in this paper. In addition to the description of the experimental procedure and installation overview, the paper describes methods based on theory and presents their basic limitations, through the presentation of experimental data. [Acknowledgment. This paper is made in a scope of the project TR 33047 “Intelligent climate control systems to achieve energy efficient regime in the complex conditions of exploitation” funded by the Ministry of Education and Science of the Republic of Serbia.

  19. Pulse regime in formation of fractal fibers

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, B. M., E-mail: bmsmirnov@gmail.com [Joint Institute for High Temperatures (Russian Federation)

    2016-11-15

    The pulse regime of vaporization of a bulk metal located in a buffer gas is analyzed as a method of generation of metal atoms under the action of a plasma torch or a laser beam. Subsequently these atoms are transformed into solid nanoclusters, fractal aggregates and then into fractal fibers if the growth process proceeds in an external electric field. We are guided by metals in which transitions between s and d-electrons of their atoms are possible, since these metals are used as catalysts and filters in interaction with gas flows. The resistance of metal fractal structures to a gas flow is evaluated that allows one to find optimal parameters of a fractal structure for gas flow propagation through it. The thermal regime of interaction between a plasma pulse or a laser beam and a metal surface is analyzed. It is shown that the basic energy from an external source is consumed on a bulk metal heating, and the efficiency of atom evaporation from the metal surface, that is the ratio of energy fluxes for vaporization and heating, is 10{sup –3}–10{sup –4} for transient metals under consideration. A typical energy flux (~10{sup 6} W/cm{sup 2}), a typical surface temperature (~3000 K), and a typical pulse duration (~1 μs) provide a sufficient amount of evaporated atoms to generate fractal fibers such that each molecule of a gas flow collides with the skeleton of fractal fibers many times.

  20. Grounded Intersectionality

    DEFF Research Database (Denmark)

    Marfelt, Mikkel Mouritz

    2016-01-01

    grounded approach to studying differences. This provides an opportunity, for scholars and practitioners, to reassess possible a priori given assumptions, and open up to new explorations beyond conventional identity theorization. Social implications – The paper suggests a need for an empirically grounded...... approach to studying social differences, which would not only create an opportunity to reassess common assumptions but also open up for explorations beyond conventional identity theorizations. Originality/value – The framework departs from traditional (critical) diversity scholarship, as it is process...

  1. Heat-transfer regimes in nuclear-reactor-pumped gas lasers

    Energy Technology Data Exchange (ETDEWEB)

    Torczynski, J.R.

    1990-01-01

    The flow induced in nuclear-reactor-pumped gas lasers by the competing effects of spatially nonuniform fission-fragment heating (pumping) and heat transfer to the walls is examined. The equations of motion are acoustically filtered (low Mach number approximation), and the resulting equations are seen to have three timescales: the duration of the heating, the time required by the heating to produce a pressure rise comparable to the initial pressure, and the time for the thermal boundary layer to grow into the center of the laser cell. Three distinct regimes emerge from consideration of the relative magnitudes of these timescales. In the negligible-conduction regime, thermal-conduction effects are small, and the motion is determined by the spatial nonuniformity of the heating. In the dominant-conduction regime, thermal-conduction effects govern the motion. In the mixed regime, the effects of thermal conduction and heating nonuniformity are comparable, but since they are oppositely directed, a complex gas motion results. Analytical solutions to the equations of motion are presented for the negligible-conduction and dominant-conduction regimes, and examples are given for all three regimes. Plots of the second spatial derivative of the density field (a quantity often used in optical analyses) are given for the negligible-conduction and the dominant-conduction regimes as functions of the appropriate similarity parameters. 26 refs., 14 figs.

  2. Thermal structure of Rikha Samba glacier, Nepal Himalayas

    Science.gov (United States)

    Sinisalo, A. K.; Fujita, K.; Zwinger, T.; Maharjan, S. B.; Gustafsson, J. M.; Joshi, S.; Stumm, D.; Litt, M.; Fukuda, T.

    2016-12-01

    Little is known about thermal regimes of Himalayan glaciers due to the challenges related to the field work in these remote, high altitudes areas. Thermal regimes defined by the environmental setting and the dynamics of the glacier are important since they can impact the glacier's melt response to climate changes and thus, the future discharge of glacier-fed catchments. In this study, we present ground penetrating radar (GPR) data analysis from Rikha Samba, a medium size glacier (5.5 km2) in central Nepal with an elevation range from 5380 to 6560 m a.s.l. We combine GPR data from two field campaigns carried out in 2010 and 2015, measured with center frequencies of 5 MHz and 30 MHz, respectively, and use intense volume scattering of the 30 MHz GPR signal as an indicator of temperate ice. Our results reveal that Rikha Samba is a polythermal glacier with a layer of temperate ice up to 100 m thick below the cold ice, and a maximum observed thickness of about 180 m. Furthermore, we investigate with ice flow models to what extend the present-day thermal structure can result from current melt water routing through cracks in the middle part of the glacier or from past convection of ice from an upstream area dominated by latent heat release of refrozen water.

  3. Amendment of the Foreign lnvestment Juridical regime in Colombia

    Directory of Open Access Journals (Sweden)

    Cristina Vargas Guzman

    1992-12-01

    Full Text Available Colombia, integrated in the Andean Group, is now going through a period of economic and institutional modernization and has initiated a serie of modifications, specially of its international trade, finantial, tax, exchange and labour regimes. These have involved some changes which guarantee legislative stability to investors and thus set the grounds for the foreign participation in the economic modernization and internationalization process in Colombia. These facilities need the support of developed countries to achieve its aims.

  4. Study on the optimal control of the ground thermal storage system in the greenhouse. Part 4; Onshitsu ni okeru taiyo energy dochu chikunetsu system ni okeru saiteki seigyo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, M. [Sanko Air Conditioning Co. Ltd., Osaka (Japan); Nakahara, N. [Kanagawa University, Yokohama (Japan)

    1996-10-27

    Three types of weight in both energy saving and optimum room temperature environment were changed to obtain the optimal control solution of the ground thermal storage system in a greenhouse. The relation diagram between the optimal solution of a performance function, and the state constraints and control function constraints was created in consideration of the energy term in a control function value area and the room temperature environment. As a result, the whole image of the performance function could be grasped in consideration of the energy term with inequality constraints and the room temperature environmental term in this study. The rate of a weighting factor in the performance function significantly influences the optimal solution. The influence on the optimal solution also changes when the optimal room temperature schedule differs. The influence that three types of rising algorithm exert on the convergence and converging speed was investigated. Superiority or inferiority occurs according to the space properties of a performance function. A zigzag method is most disadvantageous. The constraints can be converged to the optimal solution using an SUMT outer point method irrespective of the initial value. 6 refs., 6 figs., 4 tabs.

  5. Cooling in the single-photon regime of optomechanics

    Science.gov (United States)

    Nunnenkamp, Andreas; Borkje, Kjetil; Girvin, Steven

    2012-02-01

    Optomechanics experiments are rapidly approaching the regime where the radiation pressure of a single photon displaces the mechanical oscillator by more than its zero-point uncertainty. We show that in this limit the power spectrum has multiple sidebands and that the cavity response has several resonances in the resolved-sideband limit [Phys. Rev. Lett. 107, 063602 (2011)]. We then discuss how red-sideband cooling is modified in this nonlinear regime. Using Fermi's Golden rule we calculate the transition rates induced by the optical drive. In the resolved-sideband limit we find multiple cooling resonances for strong single-photon coupling. They lead to non-thermal steady states and are accompanied by multiple mechanical sidebands in the optical output spectrum. Our study provides the tools to detect and take advantage of this novel regime of optomechanics.

  6. Friction regimes in the lubricants solid-state regime

    NARCIS (Netherlands)

    Schipper, Dirk J.; Maathuis, O.; Dowson, D.; Taylor, C.M.; Childs, T.H.C.; Dalmaz, G.

    1995-01-01

    Friction measurements were performed in the lubricant's solid-state regime to study the transition from full-film lubrication, in which the separation is maintained by a solidified lubricant, to mixed lubrication. Special attention is paid to the influence of temperature (inlet viscosity) and

  7. Free Swimming in Ground Effect

    Science.gov (United States)

    Cochran-Carney, Jackson; Wagenhoffer, Nathan; Zeyghami, Samane; Moored, Keith

    2017-11-01

    A free-swimming potential flow analysis of unsteady ground effect is conducted for two-dimensional airfoils via a method of images. The foils undergo a pure pitching motion about their leading edge, and the positions of the body in the streamwise and cross-stream directions are determined by the equations of motion of the body. It is shown that the unconstrained swimmer is attracted to a time-averaged position that is mediated by the flow interaction with the ground. The robustness of this fluid-mediated equilibrium position is probed by varying the non-dimensional mass, initial conditions and kinematic parameters of motion. Comparisons to the foil's fixed-motion counterpart are also made to pinpoint the effect that free swimming near the ground has on wake structures and the fluid-mediated forces over time. Optimal swimming regimes for near-boundary swimming are determined by examining asymmetric motions.

  8. Multifunctional Aerogel Thermal Protection Systems for Hypersonic Vehicles, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The push to hypersonic flight regimes requires novel materials that are lightweight as well as thermally and structurally efficient for airframes and thermal...

  9. intensive and extensive feeding regimes

    African Journals Online (AJOL)

    production and reproduction parameters in ram lambs, under intensive and extensive feeding regimes. J.P.C. Greyling* and G.J. Taylor. Department of Animal Science, University of the Orange Free State, PO. Box 339, Bloemfontein,. 9300, South Africa. Received revised 1 July 1999; accepted 28 July 1999. Forty Dorper ...

  10. Monetary regimes in open economies

    NARCIS (Netherlands)

    Korpos, A.

    2006-01-01

    This thesis presents a two-country open economy framework for the analysis of strategic interactions among monetary authorities and wage bargaining institutions. From this perspective, the thesis investigates the economic consequences of replacing flexible and fixed exchange rate regimes with a

  11. Ground Pollution Science

    International Nuclear Information System (INIS)

    Oh, Jong Min; Bae, Jae Geun

    1997-08-01

    This book deals with ground pollution science and soil science, classification of soil and fundamentals, ground pollution and human, ground pollution and organic matter, ground pollution and city environment, environmental problems of the earth and ground pollution, soil pollution and development of geological features of the ground, ground pollution and landfill of waste, case of measurement of ground pollution.

  12. Benjamin's Ground

    Directory of Open Access Journals (Sweden)

    Rainer Nägele

    1986-09-01

    Full Text Available Benjamin‘s reading of Hölderlin in one of his earliest essays already delineates some of the major constellations of his thought. Searching for the ground of language and of poetic language in particular, Benjamin sets out to lay the ground for the possibility of literary criticism. His text enters into a specific relationship with Hölderlin's theory of poetics and poetic language. The movement of this search leads through a metaphoric relationship of "surface" and "depth" toward an ever-receding ground that can be articulated ultimately only in relation to a non-representable abyss (Abgrund . A new topography of surface and writing emerges and replaces the surface/depth relationship. Both Hölderlin's poetics and Benjamin's criticism develop a model of representation based on a radical rethinking of writing and script, marked by a "cut" or "caesura" as the precondition of representation and of the possibility of any "thing" represented. In the recurring motif of waking up, Benjamin marks the threshold of that caesura and connects it at the same time with a specific trait of modern aesthetics as embodied in Kafka's work.

  13. Friction regimes in the lubricants solid-state regime

    OpenAIRE

    Schipper, Dirk J.; Maathuis, O.; Dowson, D.; Taylor, C.M.; Childs, T.H.C.; Dalmaz, G.

    1995-01-01

    Friction measurements were performed in the lubricant's solid-state regime to study the transition from full-film lubrication, in which the separation is maintained by a solidified lubricant, to mixed lubrication. Special attention is paid to the influence of temperature (inlet viscosity) and roughness on this transition. The friction measurements showed that in the lubricants solid-state region three lubrication modes can be distinguished: A) full-film lubrication; separation is maintained b...

  14. Caracterização térmica e reológica de borracha de pneu desvulcanizada por microondas Thermal and rheological characterization of ground tire rubber devulcanized by microwaves

    Directory of Open Access Journals (Sweden)

    Carlos H. Scuracchio

    2006-03-01

    Full Text Available Borracha de pneu pós-consumo previamente particulada foi submetida a um tratamento em microondas, de forma a promover a quebra de suas ligações cruzadas, ou seja, sua desvulcanização. A influência das variáveis do processo, tais como tempo de exposição às microondas e número de etapas de tratamento, foi investigada. Após o tratamento, estes materiais foram caracterizados em termos de suas propriedades térmicas por calorimetria exploratória diferencial e reológicas por reometria capilar. Também foi feita extração de solúveis em soxhlet, para avaliar a quantidade de borracha que foi efetivamente desvulcanizada durante o tratamento por microondas. O processo de desvulcanização mostrou-se um método viável para produzir um material passível de ser moldado, de forma semelhante a uma borracha virgem. No entanto, em nenhuma condição de desvulcanização utilizada foi possível obter um material 100% solúvel, ou seja, totalmente desvulcanizado. A análise térmica sugere que ocorre um processo semelhante ao envelhecimento do material durante o tratamento com as microondas.Ground tire rubber was submitted to a microwaves treatment in order to promote its devulcanization, that is, the breaking of the crosslinks between the chains. The influence of the processing parameters, such as time of exposure to the microwaves and number of treatment steps, was investigated. After the treatment, the material was characterized in terms of its thermal, by DSC, dynamic-mechanical, by DMA and rheological, by capillary rheometry, properties. In addition, the extraction of soluble fractions was made in soxhlet, to evaluate the amount of rubber that effectively was devulcanized during the microwaves treatment. The devulcanization treatment showed to be a viable method to produce a material which can be molded, in a similar way to virgin rubber. However, the complete devulcanization of the material was not possible in any devulcanization condition

  15. Ground Truth Annotation in T Analyst

    DEFF Research Database (Denmark)

    2015-01-01

    This video shows how to annotate the ground truth tracks in the thermal videos. The ground truth tracks are produced to be able to compare them to tracks obtained from a Computer Vision tracking approach. The program used for annotation is T-Analyst, which is developed by Aliaksei Laureshyn, Ph...

  16. Atmospheric Water-Cycle Regimes and Cloud Regimes

    Science.gov (United States)

    Wong, S.; Fetzer, E. J.; L'Ecuyer, T. S.

    2013-12-01

    The relationship between the atmospheric water vapor budget and cloud properties is investigated by collocated reanalysis fields from Modern Era Retrospective-analysis for Research and Applications (MERRA) and the observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite instrument. Intensities of surface water exchange (precipitation minus evaporation) are analyzed in the space of 'dynamical regimes', which are defined by combination of large-scale water vapor advection and convergence calculated from the MERRA. The atmospheric water vapor sinks associated with mid-latitude storm systems and precipitation in the west coast of United States are mainly driven by the large-scale dynamical advection, while those associated with tropical deep convection and summertime monsoons are mainly driven by water vapor convergence. Subtropical subsidence area over the eastern ocean basins is dominated by strong water vapor divergence. These dynamical regimes are then connected to the collocated MODIS cloud top pressure and cloud optical thickness. Probability density distributions of these MODIS cloud properties associated with each dynamical regime will be presented.

  17. A Comparison Study of Quality Attributes of Ground Beef and Veal Patties and Thermal Inactivation of Escherichia coli O157:H7 after Double Pan-Broiling Under Dynamic Conditions

    Directory of Open Access Journals (Sweden)

    KaWang Li

    2017-12-01

    Full Text Available This study compared the quality variation and thermal inactivation of Escherichia coli O157:H7 in non-intact beef and veal. Coarse ground beef and veal patties (2.1 cm thick, 12.4 cm diameter, 180 g inoculated with E. coli O157:H7, aerobically stored before double pan-broiling for 0–360 s without rest or to 55, 62.5, 71.1, and 76 °C (internal temperature with 0.5- or 3.5-min rest. Microbial population and qualities including color, cooking losses, pH, water activity, fat, and moisture content, were tested. After cooking the beef and veal patties, the weight losses were 17.83–29%, the pH increased from 5.53–5.60 to 5.74–6.09, the moisture content decreased from 70.53–76.02% to 62.60–67.07%, and the fat content increased (p < 0.05 from 2.19–6.46% to 2.92–9.45%. Cooking beef and veal samples with increasing internal temperatures decreased a* and b* values and increased the L* value. Escherichia coli O157:H7 was more sensitive to heat in veal compared to beef with shorter D-value and “shoulder” time. Cooking to 71.1 and 76 °C reduced E. coli O157:H7 by >6 log CFU/g regardless of rest time. Cooking to 55 °C and 62.5 °C with a 3.5-min rest achieved an additional 1–3 log CFU/g reduction compared to the 0.5-min rest. Results should be useful for developing risk assessment of non-intact beef and veal products.

  18. 'Grounded' Politics

    DEFF Research Database (Denmark)

    Schmidt, Garbi

    2012-01-01

    A prominent strand within current migration research argues that, to understand the participation of immigrants in their host societies, we must focus on their incorporation into the cities in which they settle. This article narrows the perspective further by focusing on the role that immigrants...... play within one particular neighbourhood: Nørrebro in the Danish capital, Copenhagen. The article introduces the concept of grounded politics to analyse how groups of Muslim immigrants in Nørrebro use the space, relationships and history of the neighbourhood for identity political statements...

  19. Modeling Thermal Ignition of Energetic Materials

    National Research Council Canada - National Science Library

    Gerri, Norman J; Berning, Ellen

    2004-01-01

    This report documents an attempt to computationally simulate the mechanics and thermal regimes created when a threat perforates an armor envelope and comes in contact with stowed energetic material...

  20. Regional analysis of ground and above-ground climate

    Energy Technology Data Exchange (ETDEWEB)

    1981-12-01

    The regional suitability of underground construction as a climate control technique is discussed with reference to (1) a bioclimatic analysis of long-term weather data for 29 locations in the United States to determine appropriate above ground climate control techniques, (2) a data base of synthesized ground temperatures for the coterminous United States, and (3) monthly dew point ground temperature comparisons for identifying the relative likelihood of condensation from one region to another. It is concluded that the suitability of earth tempering as a practice and of specific earth-sheltered design stereotypes varies geographically; while the subsurface almost always provides a thermal advantage on its own terms when compared to above ground climatic data, it can, nonetheless, compromise the effectiveness of other, regionally more important climate control techniques. Also contained in the report are reviews of above and below ground climate mapping schemes related to human comfort and architectural design, and detailed description of a theoretical model of ground temperature, heat flow, and heat storage in the ground. Strategies of passive climate control are presented in a discussion of the building bioclimatic analysis procedure which has been applied in a computer analysis of 30 years of weather data for each of 29 locations in the United States.

  1. Regional analysis of ground and above-ground climate

    Science.gov (United States)

    1981-12-01

    The regional suitability of underground construction as a climate control technique is discussed with reference to (1) a bioclimatic analysis of long term weather data for 29 locations in the United States to determine appropriate above ground climate control techniques, (2) a data base of synthesized ground temperatures for the coterminous United States, and (3) monthly dew point ground temperature comparisons for identifying the relative likelihood of condensation from one region to another. It is concluded that the suitability of Earth tempering as a practice and of specific Earth sheltered design stereotypes varies geographically; while the subsurface almost always provides a thermal advantage on its own terms when compared to above ground climatic data, it can, nonetheless, compromise the effectiveness of other, regionally more important climate control techniques. Reviews of above and below ground climate mapping schemes related to human comfort and architectural design, and detailed description of a theoretical model of ground temperature, heat flow, and heat storage in the ground are included. Strategies of passive climate control are presented in a discussion of the building bioclimatic analysis procedure which has been applied in a computer analysis of 30 years of weather data for each of 20 locations in the United States.

  2. Patterns in Frozen Ground

    Science.gov (United States)

    Hallet, B.; Sletten, R. S.; Fletcher, R. C.

    2005-12-01

    The expansion and contraction of ice-cemented soils, due to seasonal and shorter term temperature fluctuations, or to the growth and decay of ice lenses in soils, produce some of the most striking geometric patterns in nature. These patterns, known as patterned ground, have diverse surface expressions including local relief, soil cracks, size-segregated mineral material, and spatial variations in vegetation density and species composition. They can be subdivided into sorted patterns, which range in size from 0.1 to 3 m and are defined by spatial differentiation of soil material according to grain size, and non-sorted patterns that may be 10's of meters in size. The processes underlying the pattern development have been elucidated through detailed observations and measurements in the field, as well as instructive numerical simulations. Substantial mechanistic insight has also been gained from recent advances in the fundamental physics of ice in porous media and in the nonlinear dynamics of granular media. Current research activity is focused on polygonal patterned ground in the Dry Valleys of Antarctica where distinct 10 to 30 m polygons are ubiquitous; they are characteristically outlined by vertical cracks that become infilled with wedges of sand. This patterned ground is of particular interest because it resembles patterns seen on the surface of Mars and because a long-term, high-resolution record exists of soil temperatures and thermal strains. The crack network, which is very similar to the networks of contraction cracks in drying mud and other contracting materials, self-organizes through interactions between thermal stresses, fracture, and the evolving pattern of cracks bounding the polygons. Initially, these cracks tend to curve to join pre-existing cracks at right angles due to the influence of these early cracks on the stress field. The evolution of the patterns toward 5 or 6-sided polygons with straight-sided cracks that join at symmetric triple junctions

  3. Simple variational ground state and pure-cat-state generation in the quantum Rabi model

    Science.gov (United States)

    Leroux, C.; Govia, L. C. G.; Clerk, A. A.

    2017-10-01

    We introduce a simple, physically motivated variational ground state for the quantum Rabi model and demonstrate that it provides a high-fidelity approximation of the true ground state in all parameter regimes (including intermediate- and strong-coupling regimes). Our variational state is constructed using Gaussian cavity states and nonorthogonal qubit pointer states and contains only three variational parameters. We use our state to develop a heuristic understanding of how the ground state evolves with increasing coupling and find a parameter regime where the ground state corresponds to the cavity being in a nearly pure Schrödinger cat state.

  4. Fluid mechanical dispersion of airborne pollutants inside urban street canyons subjecting to multi-component ventilation and unstable thermal stratifications.

    Science.gov (United States)

    Mei, Shuo-Jun; Liu, Cheng-Wei; Liu, Di; Zhao, Fu-Yun; Wang, Han-Qing; Li, Xiao-Hong

    2016-09-15

    The pedestrian level pollutant transport in street canyons with multiple aspect ratios (H/W) is numerically investigated in the present work, regarding of various unstable thermal stratification scenarios and plain surrounding. Non-isothermal turbulent wind flow, temperature field and pollutant spread within and above the street canyons are solved by the realizable k-ε turbulence model along with the enhanced wall treatment. One-vortex flow regime is observed for shallow canyons with H/W=0.5, whereas multi-vortex flow regime is observed for deep canyons with H/W=2.0. Both one-vortex and multi-vortex regimes could be observed for the street canyons with H/W=1.0, where the secondary vortex could be initiated by the flow separation and intensified by unstable thermal stratification. Air exchange rate (AER) and pollutant retention time are adopted to respectively evaluate the street canyon ventilation and pollutant removal performance. A second-order polynomial functional relationship is established between AER and Richardson number (Ri). Similar functional relationship could be established between retention time and Ri, and it is only valid for canyons with one-vortex flow regime. In addition, retention time could be prolonged abruptly for canyons with multi-vortex flow regime. Very weak secondary vortex is presented at the ground level of deep canyons with mild stratification, where pollutants are highly accumulated. However, with the decrease of Ri, pollutant concentration adjacent to the ground reduces accordingly. Present research could be applied to guide the urban design and city planning for enhancing pedestrian environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Regime Change and the Role of Airpower

    National Research Council Canada - National Science Library

    Fahrenkrug, David T

    2006-01-01

    Drawing from the vision of airpower theorists and building on insights gained from studies on various regime changes, this thesis advances a theory of regime change and outlines a strategy for the use of airpower...

  6. Regime Change and the Role of Airpower

    National Research Council Canada - National Science Library

    Fahrenkrug, David

    2003-01-01

    Drawing from the vision of airpower theorists, and building on insights gained from studies on various regime changes, this thesis advances a theory of regime change and outlines a strategy for the use of airpower...

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

    Directory of Open Access Journals (Sweden)

    Борис Шуліка

    2016-10-01

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

  8. Varying Inundation Regimes Differentially Affect Natural and ...

    Science.gov (United States)

    Climate change is altering sea-level rise rates and precipitation patterns worldwide. Coastal wetlands are vulnerable to these changes. System responses to stressors are important for resource managers and environmental stewards to understand in order to best manage them. Thin layer sand or sediment application to drowning and eroding marshes is one approach to build elevation and resilience. The above- and below-ground structure, soil carbon dioxide emissions, and pore water constituents in vegetated natural marsh sediments and sand-amended sediments were examined at varying inundation regimes between mean sea level and mean high water (0.82 m NAVD88 to 1.49 m NAVD88) in a field experiment at Laws Point, part of the Plum Island Sound Estuary (MA). Significantly lower salinities, pH, sulfides, phosphates, and ammonium were measured in the sand-amended sediments than in the natural sediments. In natural sediments there was a pattern of increasing salinity with increasing elevation while in the sand-amended sediments the trend was reversed, showing decreasing salinity with increasing elevation. Sulfide concentrations generally increased from low to high inundation with highest concentrations at the highest inundation (i.e., at the lowest elevations). High pore water phosphate concentrations were measured at low elevations in the natural sediments, but the sand-amended treatments had mostly low concentrations of phosphate and no consistent pattern with elevation. A

  9. Flow Regime Transition in Inner Grooved Minichannel Cold Plates for Cooling Hybrid Electric Power Electronics

    Science.gov (United States)

    2013-01-01

    fluids and channel sizes. Adiabatic models do not account for thermal interactions inside the channel. This is important to consider in diabatic ...electronic cooling applications where heat is typically added to the two- phase mixture. Specifically, diabatic conditions could be expected to...shift transition boundaries between bubbly/intermittent and stratified/intermittent regimes (16). As a result, diabatic flow regime maps have been

  10. Can Old Regimes Handle New Wars?

    DEFF Research Database (Denmark)

    Henningsen, Troels

    strengthen Islamist insurgents. Using a comparative case study of the regimes in Chad and Mali from 2003 to 2016 and applying a theoretical framework of regime survival in states with internal anarchy, this paper explains how regimes in the Sahel region defend themselves against insurgents. Surprisingly...

  11. Implementation Regimes and Street-Level Bureaucrats

    DEFF Research Database (Denmark)

    Winter, Søren; T. Dinesen, Peter; J. May, Peter

    -government regimes foster greater policy commitment, attention to rules, and adherence among frontline workers than is the case for a local-government implementation regime. These lead to actions of street-level bureaucrats in central-government regimes that are more in line with national policies than those...

  12. Ground Control System Description Document

    Energy Technology Data Exchange (ETDEWEB)

    Eric Loros

    2001-07-31

    The Ground Control System contributes to the safe construction and operation of the subsurface facility, including accesses and waste emplacement drifts, by maintaining the configuration and stability of the openings during construction, development, emplacement, and caretaker modes for the duration of preclosure repository life. The Ground Control System consists of ground support structures installed within the subsurface excavated openings, any reinforcement made to the rock surrounding the opening, and inverts if designed as an integral part of the system. The Ground Control System maintains stability for the range of geologic conditions expected at the repository and for all expected loading conditions, including in situ rock, construction, operation, thermal, and seismic loads. The system maintains the size and geometry of operating envelopes for all openings, including alcoves, accesses, and emplacement drifts. The system provides for the installation and operation of sensors and equipment for any required inspection and monitoring. In addition, the Ground Control System provides protection against rockfall for all subsurface personnel, equipment, and the engineered barrier system, including the waste package during the preclosure period. The Ground Control System uses materials that are sufficiently maintainable and that retain the necessary engineering properties for the anticipated conditions of the preclosure service life. These materials are also compatible with postclosure waste isolation performance requirements of the repository. The Ground Control System interfaces with the Subsurface Facility System for operating envelopes, drift orientation, and excavated opening dimensions, Emplacement Drift System for material compatibility, Monitored Geologic Repository Operations Monitoring and Control System for ground control instrument readings, Waste Emplacement/Retrieval System to support waste emplacement operations, and the Subsurface Excavation System

  13. Ground Control System Description Document

    International Nuclear Information System (INIS)

    Eric Loros

    2001-01-01

    The Ground Control System contributes to the safe construction and operation of the subsurface facility, including accesses and waste emplacement drifts, by maintaining the configuration and stability of the openings during construction, development, emplacement, and caretaker modes for the duration of preclosure repository life. The Ground Control System consists of ground support structures installed within the subsurface excavated openings, any reinforcement made to the rock surrounding the opening, and inverts if designed as an integral part of the system. The Ground Control System maintains stability for the range of geologic conditions expected at the repository and for all expected loading conditions, including in situ rock, construction, operation, thermal, and seismic loads. The system maintains the size and geometry of operating envelopes for all openings, including alcoves, accesses, and emplacement drifts. The system provides for the installation and operation of sensors and equipment for any required inspection and monitoring. In addition, the Ground Control System provides protection against rockfall for all subsurface personnel, equipment, and the engineered barrier system, including the waste package during the preclosure period. The Ground Control System uses materials that are sufficiently maintainable and that retain the necessary engineering properties for the anticipated conditions of the preclosure service life. These materials are also compatible with postclosure waste isolation performance requirements of the repository. The Ground Control System interfaces with the Subsurface Facility System for operating envelopes, drift orientation, and excavated opening dimensions, Emplacement Drift System for material compatibility, Monitored Geologic Repository Operations Monitoring and Control System for ground control instrument readings, Waste Emplacement/Retrieval System to support waste emplacement operations, and the Subsurface Excavation System

  14. Comparison of mechanical fatigue with thermal fatigue in ceramics

    International Nuclear Information System (INIS)

    Wilson, B.A.; Case, E.D.

    1993-01-01

    Thermal fatigue studies have shown a saturation of damage accumulation with cycling. Similar damage saturation has been observed for mechanical fatigue. This study compares damage saturation behavior for mechanical fatigue with thermal fatigue in ceramics. Studies of thermal fatigue of ceramics show that the accumulation of thermal shock cycling damage depends on the magnitude of the thermal shock, ΔΤ (where ΔΤ is the temperature change of the specimen from the initial temperature to the temperature of the quenching medium). Three distinct regimes of damage accumulation exist depending on the magnitude of ΔΤ. For the first regime where the thermal shock cycling is below ΔΤ c , a critical thermal shock value, there is no thermal damage detected. In the second regime where ΔΤ is higher than ΔΤ c but lower than ΔΤ 1 , the accumulating microcrack damage initially induces a rapid change in material property P. As the number of cycles increases a steady state value of properties is reached. For the third regime ΔΤ is higher than ΔΤ 1 and rapid crack growth results in fracture of the specimen. Each regime depends on ΔΤ since, for a given specimen and quenching medium, the maximum thermal shock stress is proportional to ΔΤ. So characterization of each regime by ΔΤ is indicative of the maximum stress applied by the thermal shock

  15. Measuring the effectiveness of international environmental regimes

    Energy Technology Data Exchange (ETDEWEB)

    Helm, C.; Sprinz, D.F.

    1999-05-01

    While past research has emphasized the importance of international regimes for international governance, systematic assessments of regime effects are missing. This article derives a standardized measurement concept for the effectiveness of international environmental regimes by developing an operational rational choice calculus to evaluate actual policy simultaneously against a non-regime counterfactual and a collective optimum. Subsequently, the empirical feasibility of the measurement instrument is demonstrated by way of two international treaties regulating transboundary air pollution in Europe. The results demonstrate that the regimes indeed show positive effects - but fall substantially short of the collective optima. (orig.)

  16. Adaptation in Collaborative Governance Regimes

    Science.gov (United States)

    Emerson, Kirk; Gerlak, Andrea K.

    2014-10-01

    Adaptation and the adaptive capacity of human and environmental systems have been of central concern to natural and social science scholars, many of whom characterize and promote the need for collaborative cross-boundary systems that are seen as flexible and adaptive by definition. Researchers who study collaborative governance systems in the public administration, planning and policy literature have paid less attention to adaptive capacity specifically and institutional adaptation in general. This paper bridges the two literatures and finds four common dimensions of capacity, including structural arrangements, leadership, knowledge and learning, and resources. In this paper, we focus on institutional adaptation in the context of collaborative governance regimes and try to clarify and distinguish collaborative capacity from adaptive capacity and their contributions to adaptive action. We posit further that collaborative capacities generate associated adaptive capacities thereby enabling institutional adaptation within collaborative governance regimes. We develop these distinctions and linkages between collaborative and adaptive capacities with the help of an illustrative case study in watershed management within the National Estuary Program.

  17. Operation of the RA research nuclear reactor under forced regime

    International Nuclear Information System (INIS)

    Mitrovic, S.

    1964-01-01

    Ra reactor was designed for operation at nominal power of 6.5 MW and under forced regime. From the start of operation in 1959 until the general refurbishment in 1963 it was not operated under forced regime. At reactor power of 10 MW the mean thermal neutron flux increases from 3 to 4.6 10 13 n cm -2 sec -1 , the maximum neutron flux increases from 6 to 9.3 10 13 n cm -2 sec -1 , and at the exit of the experimental channel it increases from 5 to 7.7 10 9 n cm -2 sec -1 . In order to achieve safer and more suitable operating conditions, winter period of 1963 was chosen for the first increase of reactor power level, because of low temperatures in the secondary coolant loop. This paper contains the most relevant data concerned with the reactor operation at increased power

  18. STEADY-STATE HEAT REJECTION RATES FOR A COAXIAL BOREHOLE HEAT EXCHANGER DURING PASSIVE AND ACTIVE COOLING DETERMINED WITH THE NOVEL STEP THERMAL RESPONSE TEST METHOD

    Directory of Open Access Journals (Sweden)

    Marija Macenić

    2018-01-01

    Full Text Available At three locations in Zagreb, classical and extended thermal response test (TRT was conducted on installed coaxial heat exchangers. With classic TR test, thermogeological properties of the ground and thermal resistance of the borehole were determined at each location. It is seen that thermal conductivity of the ground varies, due to difference in geological profile of the sites. In addition, experimental research of steady-state thermal response step test (SSTRST was carried out to determine heat rejection rates for passive and active cooling in steady state regime. Results showed that heat rejection rate is only between 8-11 W/m, which indicates that coaxial system is not suitable for passive cooling demands. Furthermore, the heat pump in passive cooling mode uses additional plate heat exchanger where there is additional temperature drop of working fluid by approximately 1,5 °C. Therefore, steady-state rejection rate for passive cooling is even lower for a real case project. Coaxial heat exchanger should be always designed for an active cooling regime with an operation of a heat pump compressor in a classical vapour compression refrigeration cycle.

  19. Effectiveness of Existing International Nuclear Liability Regime

    International Nuclear Information System (INIS)

    Al-Doais, Salwa; Kessel, Daivd

    2015-01-01

    The first convention was the Paris Convention on Third Party Liability in the Field of Nuclear Energy (the Paris Convention) had been adopted on 29 July 1960 under the auspices of the OECD, and entered into force on 1 April 1968. In 1963,the Brussels Convention - supplementary to the Paris Convention- was adopted in to provide additional funds to compensate damage as a result of a nuclear incident where Paris Convention funds proved to be insufficient. The IAEA's first convention was the Vienna Convention on Civil Liability for Nuclear Damage (the Vienna Convention) which adopted on 21 May 1963,and entered into force in 1977. Both the Paris Convention and the Vienna Convention laid down very similar nuclear liability rules based on the same general principles. The broad principles in these conventions can be summarized as follows: 1- The no-fault liability principle (strict liability) 2- Liability is channeled exclusively to the operator of the nuclear installation (legal channeling) 3- Only courts of the state in which the nuclear accident occurs would have jurisdiction (exclusive jurisdiction) 4- Limitation of the amount of liability and the time frame for claiming damages (limited liability) 5- The operator is required to have adequate insurance or financial guarantees to the extent of its liability amount (liability must be financially secured). 6- Liability is limited in time. Compensation rights are extinguished after specific time. 7- Non-discrimination of victims on the grounds of nationality, domicile or residence. Nuclear liability conventions objective is to provide adequate compensation payments to victims of a nuclear accident. Procedures for receiving these compensation are controlled by some rules such as exclusive jurisdiction, that rule need a further amendment to ensure the effectiveness of the exiting nuclear liability regime . Membership of the Conventions is a critical issue, because the existence of the conventions without being party to

  20. Hall effect in hopping regime

    Energy Technology Data Exchange (ETDEWEB)

    Avdonin, A., E-mail: avdonin@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Skupiński, P. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Grasza, K. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Institute of Electronic Materials Technology, ul. Wólczyńska 133, 01-919 Warszawa (Poland)

    2016-02-15

    A simple description of the Hall effect in the hopping regime of conductivity in semiconductors is presented. Expressions for the Hall coefficient and Hall mobility are derived by considering averaged equilibrium electron transport in a single triangle of localization sites in a magnetic field. Dependence of the Hall coefficient is analyzed in a wide range of temperature and magnetic field values. Our theoretical result is applied to our experimental data on temperature dependence of Hall effect and Hall mobility in ZnO. - Highlights: • Expressions for Hall coefficient and mobility for hopping conductivity are derived. • Theoretical result is compared with experimental curves measured on ZnO. • Simultaneous action of free and hopping conduction channels is considered. • Non-linearity of hopping Hall coefficient is predicted.

  1. Reassessing the nuclear liability regime

    International Nuclear Information System (INIS)

    Havinh Phuong

    1985-01-01

    The nuclear liability regime was thoroughly reviewed by nuclear plant operators, officials of regulatory authorities, and legal and insurance experts at the Symposium on Nuclear Third Party Liability and Insurance, held in September 1984 in Munich, Federal Republic of Germany. The symposium highlighted specific areas where adjustments or improvements would be needed in order to cope with practical problems encountered or emerging issues. By focusing on questions of legitimate concern to the public, it also sought to promote confidence in a compensation system for public protection that is in many ways unique. Topics addressed included the following: greater harmonization of the compensation amounts for nuclear damage established in different countries and in territorial scope; the concept of unlimited liability; the time limitation for compensation claims; the problem of proving causation; the concept of nuclear damage; and insurance coverage

  2. Unitary Housing Regimes in Transition

    DEFF Research Database (Denmark)

    Bengtsson, Bo; Jensen, Lotte

    2013-01-01

    Path dependence is strong in housing institutions and policy. In both Denmark and Sweden, today’s universal and ‘unitary’ (Kemeny) housing regimes can be traced back to institutions that were introduced fifty years back in history or more. Recently, universal and unitary housing systems...... in Scandinavia, and elsewhere, are under challenge from strong political and economic forces. These challenges can be summarized as economic cutbacks, privatization and Europeanization. Although both the Danish and the Swedish housing system are universal and unitary in character, they differ considerably...... in institutional detail. Both systems have corporatist features, however in Denmark public housing is based on local tenant democracy and control, and in Sweden on companies owned and controlled by the municipalities, combined with a centralized system of rent negotiations. In the paper the present challenges...

  3. Transient thermal modeling of permafrost conditions in Southern Norway

    Directory of Open Access Journals (Sweden)

    S. Westermann

    2013-04-01

    Full Text Available Thermal modeling is a powerful tool to infer the temperature regime of the ground in permafrost areas. We present a transient permafrost model, CryoGrid 2, that calculates ground temperatures according to conductive heat transfer in the soil and in the snowpack. CryoGrid 2 is forced by operational air temperature and snow-depth products for potential permafrost areas in Southern Norway for the period 1958 to 2009 at 1 km2 spatial resolution. In total, an area of about 80 000 km2 is covered. The model results are validated against borehole temperatures, permafrost probability maps from "bottom temperature of snow" measurements and inventories of landforms indicative of permafrost occurrence. The validation demonstrates that CryoGrid 2 can reproduce the observed lower permafrost limit to within 100 m at all validation sites, while the agreement between simulated and measured borehole temperatures is within 1 K for most sites. The number of grid cells with simulated permafrost does not change significantly between the 1960s and 1990s. In the 2000s, a significant reduction of about 40% of the area with average 2 m ground temperatures below 0 °C is found, which mostly corresponds to degrading permafrost with still negative temperatures in deeper ground layers. The thermal conductivity of the snow is the largest source of uncertainty in CryoGrid 2, strongly affecting the simulated permafrost area. Finally, the prospects of employing CryoGrid 2 as an operational soil-temperature product for Norway are discussed.

  4. The climate space of fire regimes in north-western North America

    Science.gov (United States)

    Whitman, Ellen; Batllori, Enric; Parisien, Marc-André; Miller, Carol; Coop, Jonathan D.; Krawchuk, Meg A.; Chong, Geneva W.; Haire, Sandra L.

    2015-01-01

    Aim. Studies of fire activity along environmental gradients have been undertaken, but the results of such studies have yet to be integrated with fire-regime analysis. We characterize fire-regime components along climate gradients and a gradient of human influence. Location. We focus on a climatically diverse region of north-western North America extending from northern British Columbia, Canada, to northern Utah and Colorado, USA.Methods. We used a multivariate framework to collapse 12 climatic variables into two major climate gradients and binned them into 73 discrete climate domains. We examined variation in fire-regime components (frequency, size, severity, seasonality and cause) across climate domains. Fire-regime attributes were compiled from existing databases and Landsat imagery for 1897 large fires. Relationships among the fire-regime components, climate gradients and human influence were examined through bivariate regressions. The unique contribution of human influence was also assessed.Results. A primary climate gradient of temperature and summer precipitation and a secondary gradient of continentality and winter precipitation in the study area were identified. Fire occupied a distinct central region of such climate space, within which fire-regime components varied considerably. We identified significant interrelations between fire-regime components of fire size, frequency, burn severity and cause. The influence of humans was apparent in patterns of burn severity and ignition cause.Main conclusions. Wildfire activity is highest where thermal and moisture gradients converge to promote fuel production, flammability and ignitions. Having linked fire-regime components to large-scale climate gradients, we show that fire regimes – like the climate that controls them – are a part of a continuum, expanding on models of varying constraints on fire activity. The observed relationships between fire-regime components, together with the distinct role of climatic

  5. All-regime combined-cycle plant: Engineering solutions

    Science.gov (United States)

    Berezinets, P. A.; Tumanovskii, G. G.; Tereshina, G. E.; Krylova, I. N.; Markina, V. N.; Migun, E. N.

    2016-12-01

    The development of distributed power generation systems as a supplement to the centralized unified power grid increases the operational stability and efficiency of the entire power generation industry and improves the power supply to consumers. An all-regime cogeneration combined-cycle plant with a power of 20-25 mW (PGU-20/25T) and an electrical efficiency above 50% has been developed at the All-Russia Thermal Engineering Institute (ATEI) as a distributed power generation object. The PGU-20/25T two-circuit cogeneration plant provides a wide electrical and thermal power adjustment range and the absence of the mutual effect of electrical and thermal power output regimes at controlled frequency and power in a unified or isolated grid. The PGU-20/25T combined-cycle plant incorporates a gas-turbine unit (GTU) with a power of 16 MW, a heat recovery boiler (HRB) with two burners (before the boiler and the last heating stage), and a cogeneration steam turbine with a power of 6/9 MW. The PGU-20/25T plant has a maximum electrical power of 22 MW and an efficiency of 50.8% in the heat recovery regime and a maximum thermal power output of 16.3 MW (14 Gcal/h) in the cogeneration regime. The use of burners can increase the electrical power to 25 MW in the steam condensation regime at an efficiency of 49% and the maximum thermal power output to 29.5 MW (25.4 Gcal/h). When the steam turbine is shut down, the thermal power output can grow to 32.6 MW (28 Gcal/h). The innovative equipment, which was specially developed for PGU-20/25T, improves the reliability of this plant and simplifies its operation. Among this equipment are microflame burners in the heat recovery boiler, a vacuum system based on liquid-ring pumps, and a vacuum deaerator. To enable the application of PGU-20/25T in water-stressed regions, an air condenser preventing the heat-transfer tubes from the risk of covering with ice during operation in frost air has been developed. The vacuum system eliminates the need for

  6. Non-equilibrium steady state in the hydro regime

    Energy Technology Data Exchange (ETDEWEB)

    Pourhasan, Razieh [Science Institute, University of Iceland,Dunhaga 5, 107 Reykjavik (Iceland)

    2016-02-01

    We study the existence and properties of the non-equilibrium steady state which arises by putting two copies of systems at different temperatures into a thermal contact. We solve the problem for the relativistic systems that are described by the energy-momentum of a perfect hydro with general equation of state (EOS). In particular, we examine several simple examples: a hydro with a linear EOS, a holographic CFT perturbed by a relevant operator and a barotropic fluid, i.e., P=P(E). Our studies suggest that the formation of steady state is a universal result of the hydro regime regardless of the kind of fluid.

  7. Accommodating human values in the climate regime

    Directory of Open Access Journals (Sweden)

    Rosalind Cook

    2008-12-01

    Full Text Available The climate regime addresses one of the most important challenges facing humankind today. However, while the environmental and economic sides of the problem are well represented, it lacks the inclusion of social and human aspects. The human rights regime, in contrast, is a regime which has been established precisely to implement human values. This article ex-plains the problems of climate change in terms of human values and argues that some proce-dures from the human rights regime offer possibilities for improvement. It is submitted that through the inclusion of human rights instruments, such as individual communication, pro-gressive realisation and authoritative interpretation, the inclusion of human values into the climate regime will be facilitated. This article presents these instruments and discusses their potential for inclusion in the climate regime.

  8. State Structure and Political Regime Structure

    OpenAIRE

    Paul – Iulian Nedelcu

    2012-01-01

    The political regime is the concrete form of organization and functioning of political system andtherefore, the regime means the concrete way of organize, institutionalize and function a political systemand of the exercise of political power by a social-political force in a social community or global socialistem. The political regime is not limited to institutions and state bodies, but it covers the entire politicalsystem. Form of expression in social practice plan is the result of balance of...

  9. De Facto Regimes in International Law

    OpenAIRE

    Essen, Jonte van

    2012-01-01

    The ambiguous position of de facto regimes in international law has long been the subject of scholarly debate and a source of political conflict. An assessment of the current standing of these regimes in international law and the consequences of actions by international actors on this status has, however, been long overdue. The manner in which de facto regimes are regarded internationally has serious consequences for the individuals under the influence of this legal grey area. Therefore, the ...

  10. Thermalized axion inflation

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Ricardo Z.; Notari, Alessio, E-mail: rferreira@icc.ub.edu, E-mail: notari@ub.edu [Departament de Física Quàntica i Astrofísica i Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès, 1, E-08028, Barcelona (Spain)

    2017-09-01

    We analyze the dynamics of inflationary models with a coupling of the inflaton φ to gauge fields of the form φ F F-tilde / f , as in the case of axions. It is known that this leads to an instability, with exponential amplification of gauge fields, controlled by the parameter ξ= φ-dot /(2 fH ), which can strongly affect the generation of cosmological perturbations and even the background. We show that scattering rates involving gauge fields can become larger than the expansion rate H , due to the very large occupation numbers, and create a thermal bath of particles of temperature T during inflation. In the thermal regime, energy is transferred to smaller scales, radically modifying the predictions of this scenario. We thus argue that previous constraints on ξ are alleviated. If the gauge fields have Standard Model interactions, which naturally provides reheating, they thermalize already at ξ∼>2.9, before perturbativity constraints and also before backreaction takes place. In absence of SM interactions (i.e. for a dark photon), we find that gauge fields and inflaton perturbations thermalize if ξ∼>3.4; however, observations require ξ∼>6, which is above the perturbativity and backreaction bounds and so a dedicated study is required. After thermalization, though, the system should evolve non-trivially due to the competition between the instability and the gauge field thermal mass. If the thermal mass and the instabilities equilibrate, we expect an equilibrium temperature of T {sub eq} ≅ ξ H / g-bar where g-bar is the effective gauge coupling. Finally, we estimate the spectrum of perturbations if φ is thermal and find that the tensor to scalar ratio is suppressed by H /(2 T ), if tensors do not thermalize.

  11. Surface modification with a remote atmospheric pressure plasma: dc glow discharge and surface streamer regime

    International Nuclear Information System (INIS)

    Temmerman, Eef; Akishev, Yuri; Trushkin, Nikolay; Leys, Christophe; Verschuren, Jo

    2005-01-01

    A remote atmospheric pressure discharge working with ambient air is used for the near room temperature treatment of polymer foils and textiles of varying thickness. The envisaged plasma effect is an increase in the surface energy of the treated material, leading, e.g., to a better wettability or adhesion. Changes in wettability are examined by measuring the contact angle or the liquid absorptive capacity. Two regimes of the remote atmospheric pressure discharge are investigated: the glow regime and the streamer regime. These regimes differ mainly in power density and in the details of the electrode design. The results show that this kind of discharge makes up a convenient non-thermal plasma source to be integrated into a treatment installation working at atmospheric pressure

  12. Targeting autocrats : Economic sanctions and regime change

    NARCIS (Netherlands)

    Oechslin, M.C.

    2014-01-01

    When it comes to international economic sanctions, the most frequent goal is regime change and democratization. Yet, past experiences suggest that such sanctions are often ineffective; moreover, quite paradoxically, targeted regimes tend to respond with policies that amplify the sanctions’ harmful

  13. Strengthening the nuclear non-proliferation regime

    International Nuclear Information System (INIS)

    Carlson, J.

    2003-01-01

    Although the nuclear non-proliferation regime has enjoyed considerable success, today the regime has never been under greater threat. Three states have challenged the objectives of the NPT, and there is a technology challenge - the spread of centrifuge enrichment technology and know-how. A major issue confronting the international community is, how to deal with a determined proliferator? Despite this gloomy scenario, however, the non-proliferation regime has considerable strengths - many of which can be developed further. The regime comprises complex interacting and mutually reinforcing elements. At its centre is the NPT - with IAEA safeguards as the Treaty's verification mechanism. Important complementary elements include: restraint in the supply and the acquisition of sensitive technologies; multilateral regimes such as the CTBT and proposed FMCT; various regional and bilateral regimes; the range of security and arms control arrangements outside the nuclear area (including other WMD regimes); and the development of proliferation-resistant technologies. Especially important are political incentives and sanctions in support of non-proliferation objectives. This paper outlines some of the key issues facing the non-proliferation regime

  14. Decentralization and Diversification in Forest Management Regimes ...

    African Journals Online (AJOL)

    In recent years in many African countries, including Tanzania, there has been a shift of paradigm from centralized and state driven forest management regimes to decentralized and people- centred forest management regime. The inception of a Tanzania forest policy of 1998 resulted in the institutionalization of community ...

  15. Multiscale regime shifts and planetary boundaries

    NARCIS (Netherlands)

    Hughes, T.P.; Carpenter, S.; Rockstrom, J.; Scheffer, M.; Walker, B.

    2013-01-01

    Life on Earth has repeatedly displayed abrupt and massive changes in the past, and there is no reason to expect that comparable planetary-scale regime shifts will not continue in the future. Different lines of evidence indicate that regime shifts occur when the climate or biosphere transgresses a

  16. LEGAL MATRIMONIAL REGIME IN B&H

    Directory of Open Access Journals (Sweden)

    Boris Krešić

    2011-12-01

    Full Text Available Matrimonial regime between spouses or between extramarital partners, and between parents and children is regulated by the Family Law Act of Bosnia and Herzegovina Federation, hereinafter FLA B&HF (SG FBiH 35/05, 41/05, Family Law Act of the Republic of Srpska, hereinafter FLA RS (SG RS”54/02, 41/08 and the Family Law Act of Brčko District, hereinafter FLA BD (SG RS, 66/07. Legal rules used for the regulation of the matrimonial regime between spouses, as well as between spouses and third parties make matrimonial regime (Ponjavić, 2005, p. 361. Matrimonial regime between spouses in family legislation in Bosnia and Herzegovina (B&H is regulated in two following ways: as legal matrimonial regime and as contract matrimonial regime. Legal regime is the one which applies on spouses if not arranged otherwise prior to contracting marriage or during marriage. In this paper the author indicates the differences between the legal matrimonial regimes of the two entities as well as those between the entities and Brčko District of Bosnia and Herzegovina.

  17. Thermal effects of metamorphic reactions in a three-component slab

    DEFF Research Database (Denmark)

    Chemia, Zurab; Dolejš, David; Steinle-Neumann, Gerd

    2010-01-01

    Thermal evolution of a subducting crust is of primary importance for understanding physical properties, phase transformations, fluid migration and melting regimes at convergent plate boundaries. Various factors influencing the thermal structure of a subduction zone have been considered previously...

  18. Convection and exchangers in variable regime; Convection et echangeurs en regime variable

    Energy Technology Data Exchange (ETDEWEB)

    Bagui, F.; Abdelghani-Idrissi, M.A. [Rouen Univ. IUT, Centre de Developpement Durable, 76 - Mont Saint Aignan (France); Bagui, F. [Ecole d' Ingenieurs CESI, 76 - Mont Saint Aignan (France); Desmet, B.; Lalot, S.; Harmand, S. [Valenciennes et du Hainaut-Cambresis Univ., Lab. de Mecanique et Energetique, 59 - Valenciennes (France); Maillet, D. [Institut National Polytechnique, INPL-UHP Nancy-1, LEMTA-CNRS UMR 7563, 54 - Vandoeuvre les Nancy (France)

    2005-07-01

    This session about convection and exchangers in variable regime gathers three articles dealing with: the transient regimes of tubular heat exchangers; heat exchangers and convection in non-permanent regime; and the limitations of the H coefficient: two short-time and short-scale examples. (J.S.)

  19. CRM in the Regime of Nonresonant Bunching

    CERN Document Server

    Bandurkin, I V; Savilov, A V

    2005-01-01

    New regime of electron-wave coupling in cyclotron resonance maser (CRM) is proposed. In this regime, during the most part of interaction process electrons move in the field of rf wave which is relatively far from cyclotron resonance. It is shown, that if resonance mismatch is chosen properly, an effective bunching takes place, an amplitude of forming rf current weakly depending on the velocity spread. Simulations show that, whereas the efficiency of traditional regimes quickly decreases with increasing velocity spread, efficiency of the proposed scheme practically does not change and for relative value of spread in transverse velocities of 40% is twice as large as corresponding efficiency of the conventional regimes. The regime seems to be also prospective for realization of CRM with frequency multiplication. In such a scheme, resonance mismatch for low-frequency wave in bunching section should be such that high-frequency wave be in resonance with the beam. Thus, the device operates like the single-frequency ...

  20. Hanford site ground water protection management plan

    International Nuclear Information System (INIS)

    1994-10-01

    Ground water protection at the Hanford Site consists of preventative and remedial measures that are implemented in compliance with a variety of environmental regulations at local, state, and federal levels. These measures seek to ensure that the resource can sustain a broad range of beneficial uses. To effectively coordinate and ensure compliance with applicable regulations, the U.S. Department of Energy has issued DOE Order 5400.1 (DOE 1988a). This order requires all U.S. Department of Energy facilities to prepare separate ground water protection program descriptions and plans. This document describes the Ground Water Protection Management Plan (GPMP) for the Hanford Site located in the state of Washington. DOE Order 5400.1 specifies that the GPMP covers the following general topical areas: (1) documentation of the ground water regime; (2) design and implementation of a ground water monitoring program to support resource management and comply with applicable laws and regulations; (3) a management program for ground water protection and remediation; (4) a summary and identification of areas that may be contaminated with hazardous waste; (5) strategies for controlling hazardous waste sources; (6) a remedial action program; and (7) decontamination, decommissioning, and related remedial action requirements. Many of the above elements are currently covered by existing programs at the Hanford Site; thus, one of the primary purposes of this document is to provide a framework for coordination of existing ground water protection activities. The GPMP provides the ground water protection policy and strategies for ground water protection/management at the Hanford Site, as well as an implementation plan to improve coordination of site ground water activities

  1. Method for measuring thermal properties using a long-wavelength infrared thermal image

    Science.gov (United States)

    Walker, Charles L [Albuquerque, NM; Costin, Laurence S [Albuquerque, NM; Smith, Jody L [Albuquerque, NM; Moya, Mary M [Albuquerque, NM; Mercier, Jeffrey A [Albuquerque, NM

    2007-01-30

    A method for estimating the thermal properties of surface materials using long-wavelength thermal imagery by exploiting the differential heating histories of ground points in the vicinity of shadows. The use of differential heating histories of different ground points of the same surface material allows the use of a single image acquisition step to provide the necessary variation in measured parameters for calculation of the thermal properties of surface materials.

  2. Scaling-up permafrost thermal measurements in western Alaska using an ecotype approach

    Directory of Open Access Journals (Sweden)

    W. L. Cable

    2016-10-01

    Full Text Available Permafrost temperatures are increasing in Alaska due to climate change and in some cases permafrost is thawing and degrading. In areas where degradation has already occurred the effects can be dramatic, resulting in changing ecosystems, carbon release, and damage to infrastructure. However, in many areas we lack baseline data, such as subsurface temperatures, needed to assess future changes and potential risk areas. Besides climate, the physical properties of the vegetation cover and subsurface material have a major influence on the thermal state of permafrost. These properties are often directly related to the type of ecosystem overlaying permafrost. In this paper we demonstrate that classifying the landscape into general ecotypes is an effective way to scale up permafrost thermal data collected from field monitoring sites. Additionally, we find that within some ecotypes the absence of a moss layer is indicative of the absence of near-surface permafrost. As a proof of concept, we used the ground temperature data collected from the field sites to recode an ecotype land cover map into a map of mean annual ground temperature ranges at 1 m depth based on analysis and clustering of observed thermal regimes. The map should be useful for decision making with respect to land use and understanding how the landscape might change under future climate scenarios.

  3. StreamThermal: A software package for calculating thermal metrics from stream temperature data

    Science.gov (United States)

    Tsang, Yin-Phan; Infante, Dana M.; Stewart, Jana S.; Wang, Lizhu; Tingly, Ralph; Thornbrugh, Darren; Cooper, Arthur; Wesley, Daniel

    2016-01-01

    Improving quality and better availability of continuous stream temperature data allows natural resource managers, particularly in fisheries, to understand associations between different characteristics of stream thermal regimes and stream fishes. However, there is no convenient tool to efficiently characterize multiple metrics reflecting stream thermal regimes with the increasing amount of data. This article describes a software program packaged as a library in R to facilitate this process. With this freely-available package, users will be able to quickly summarize metrics that describe five categories of stream thermal regimes: magnitude, variability, frequency, timing, and rate of change. The installation and usage instruction of this package, the definition of calculated thermal metrics, as well as the output format from the package are described, along with an application showing the utility for multiple metrics. We believe this package can be widely utilized by interested stakeholders and greatly assist more studies in fisheries.

  4. Ground water and energy

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    This national workshop on ground water and energy was conceived by the US Department of Energy's Office of Environmental Assessments. Generally, OEA needed to know what data are available on ground water, what information is still needed, and how DOE can best utilize what has already been learned. The workshop focussed on three areas: (1) ground water supply; (2) conflicts and barriers to ground water use; and (3) alternatives or solutions to the various issues relating to ground water. (ACR)

  5. Abrupt climate-independent fire regime changes

    Science.gov (United States)

    Pausas, Juli G.; Keeley, Jon E.

    2014-01-01

    Wildfires have played a determining role in distribution, composition and structure of many ecosystems worldwide and climatic changes are widely considered to be a major driver of future fire regime changes. However, forecasting future climatic change induced impacts on fire regimes will require a clearer understanding of other drivers of abrupt fire regime changes. Here, we focus on evidence from different environmental and temporal settings of fire regimes changes that are not directly attributed to climatic changes. We review key cases of these abrupt fire regime changes at different spatial and temporal scales, including those directly driven (i) by fauna, (ii) by invasive plant species, and (iii) by socio-economic and policy changes. All these drivers might generate non-linear effects of landscape changes in fuel structure; that is, they generate fuel changes that can cross thresholds of landscape continuity, and thus drastically change fire activity. Although climatic changes might contribute to some of these changes, there are also many instances that are not primarily linked to climatic shifts. Understanding the mechanism driving fire regime changes should contribute to our ability to better assess future fire regimes.

  6. De Facto Regimes in International Law

    Directory of Open Access Journals (Sweden)

    Jonte van Essen

    2012-02-01

    Full Text Available The ambiguous position of de facto regimes in international law has long been the subject of scholarly debate and a source of political conflict. An assessment of the current standing of these regimes in international law and the consequences of actions by international actors on this status has, however, been long overdue. The manner in which de facto regimes are regarded internationally has serious consequences for the individuals under the influence of this legal grey area. Therefore, the study into this problem and possible solutions is of great significance. The 2011 developments in Northern Africa underline the need of contemporary research into this area. This essay aims to clarify the position of de facto regimes in international law and the influence on their status by actions of international actors. The author first argues that de facto regimes have rights and obligations under international law, which provide them with (some form of international legal personality. He then pleads for a reconsideration of the contemporary legal treatment of these regimes. The author argues against the current system of government recognition and proposes a system that better addresses the needs of both de facto regimes and the international community. 

  7. Initial Descent of a Thermal and the Application to Downdraughts

    Science.gov (United States)

    Kruger, Emily; Burridge, Henry; Rooney, Gabriel; Linden, Paul

    2017-11-01

    Downward moving cold air within thunderstorms, known as downdraughts, can be used to determine the severity of a storm. Therefore an understanding of them is useful for weather forecasting. Typically in weather forecasting these downdrafts are modelled using the theory of a plume from from Morton, Taylor and Turner (1956), which inherently assumes that the plume is long and thin. Downdrafts are generally wider than they are high and hence deviate from the Morton, Taylor and Turner theory. We perform experiments using finite releases of dense fluid from a cylinder of varying lengths. By tracking the edges of the release we can find the velocity and radius of the descent and gravity current after impact. In doing so we find that the descent has two regimes, an initial phase and then a self similar thermal, and the axisymmetric gravity current varies depending on which regime the descent impacts the ground in. A theoretical model is proposed for this initial phase and compared to the experimental data. We hope that these results and future work will allow us to better inform forecasting of weather arising from such downdraughts.

  8. Framing of regimes and transition strategies

    DEFF Research Database (Denmark)

    Jensen, Jens Stissing

    2012-01-01

    This article suggests that transition strategies are always formulated in the context of specific representations of the regime and the challenges it faces. It is argued that the framing of a regime affects the envisioning of transition strategies. An analysis of the current development agenda fo...... for the housing construction sector in Denmark reveals the relevance and impacts of different regime framings. It is proposed that the ability to cope with framing issues as situated and political processes is at the core of the governance of transitions....

  9. Near-field radiative heat transfer between parallel structures in the deep subwavelength regime

    Science.gov (United States)

    St-Gelais, Raphael; Zhu, Linxiao; Fan, Shanhui; Lipson, Michal

    2016-06-01

    Thermal radiation between parallel objects separated by deep subwavelength distances and subject to large thermal gradients (>100 K) can reach very high magnitudes, while being concentrated on a narrow frequency distribution. These unique characteristics could enable breakthrough technologies for thermal transport control and electricity generation (for example, by radiating heat exactly at the bandgap frequency of a photovoltaic cell). However, thermal transport in this regime has never been achieved experimentally due to the difficulty of maintaining large thermal gradients over nanometre-scale distances while avoiding other heat transfer mechanisms, namely conduction. Here, we show near-field radiative heat transfer between parallel SiC nanobeams in the deep subwavelength regime. The distance between the beams is controlled by a high-precision micro-electromechanical system (MEMS). We exploit the mechanical stability of nanobeams under high tensile stress to minimize thermal buckling effects, therefore keeping control of the nanometre-scale separation even at large thermal gradients. We achieve an enhancement of heat transfer of almost two orders of magnitude with respect to the far-field limit (corresponding to a 42 nm separation) and show that we can maintain a temperature gradient of 260 K between the cold and hot surfaces at ∼100 nm distance.

  10. Heat transfer regimes for a flow of water at supercritcal conditions in vertical channels

    Science.gov (United States)

    Deev, V. I.; Kharitonov, V. S.; Churkin, A. N.; Baisov, A. M.

    2017-11-01

    Heat transfer regimes observed in experiments with water at supercritical conditions flowing in vertical channels of various cross-sections (such as round pipes, annulus, or rod bundles) are analyzed. In accordance with the established practice, the normal and the deteriorated heat transfer regimes were singled out as the basic regimes specific for heat carriers with highly variable properties. At the same time, it has been established that most published experimental data on supercritical pressure water heat transfer along the length of test sections demonstrate combined (or transient) heat transfer regimes. The features can be presented as a superposition of characteristics of the above-mentioned basic regimes. The combined regimes are not stable in certain ranges of water flow conditions in which sudden transitions between the basic regimes can occur. A system of similarity criteria governing heat transfer rate in the vicinity of the critical point is examined. As applicable to cores of water-cooled reactors, due to a small hydraulic diameter of cooling channels, buoyancy forces acting in these channels are negligible as compared with the inertia effects caused by thermal acceleration of the flow and viscous force. This concept yields two integrated criteria whose use in the correction factors for the basic heat transfer equation, which we proposed previously for the normal regimes, adequately (with an error of 20-25%) describes the specific of the heat transfer coefficient in the normal, deteriorated, and combined regimes. A system of equations is proposed for design calculation of heat transfer in channels of nuclear reactors cooled with supercritical pressure water.

  11. Coupled Monitoring and Inverse Modeling to Investigate Surface - Subsurface Hydrological and Thermal Dynamics in the Arctic Tundra

    Science.gov (United States)

    Tran, A. P.; Dafflon, B.; Hubbard, S. S.; Bisht, G.; Peterson, J.; Ulrich, C.; Romanovsky, V. E.; Kneafsey, T. J.; Wu, Y.

    2015-12-01

    Quantitative characterization of the soil surface-subsurface hydrological and thermal processes is essential as they are primary factors that control the biogeochemical processes, ecological landscapes and greenhouse gas fluxes. In the Artic region, the surface-subsurface hydrological and thermal regimes co-interact and are both largely influenced by soil texture and soil organic content. In this study, we present a coupled inversion scheme that jointly inverts hydrological, thermal and geophysical data to estimate the vertical profiles of clay, sand and organic contents. Within this inversion scheme, the Community Land Model (CLM4.5) serves as a forward model to simulate the land-surface energy balance and subsurface hydrological-thermal processes. Soil electrical conductivity (from electrical resistivity tomography), temperature and water content are linked together via petrophysical and geophysical models. Particularly, the inversion scheme accounts for the influences of the soil organic and mineral content on both of the hydrological-thermal dynamics and the petrophysical relationship. We applied the inversion scheme to the Next Generation Ecosystem Experiments (NGEE) intensive site in Barrow, AK, which is characterized by polygonal-shaped arctic tundra. The monitoring system autonomously provides a suite of above-ground measurements (e.g., precipitation, air temperature, wind speed, short-long wave radiation, canopy greenness and eddy covariance) as well as below-ground measurements (soil moisture, soil temperature, thaw layer thickness, snow thickness and soil electrical conductivity), which complement other periodic, manually collected measurements. The preliminary results indicate that the model can well reproduce the spatiotemporal dynamics of the soil temperature, and therefore, accurately predict the active layer thickness. The hydrological and thermal dynamics are closely linked to the polygon types and polygon features. The results also enable the

  12. The Two Regimes of Postwar Shipping

    DEFF Research Database (Denmark)

    Iversen, Martin Jes; Tenold, Stig

    2014-01-01

    The aim of this article is to illustrate the most important changes in the regulatory framework of the shipping sector from the 1960s to 2010, and to analyse the basis for, and effects of, these changes. In order to explain how the transformation has occurred, we use two traditional maritime...... nations—Denmark and Norway—as case studies. First, we introduce the two regimes of Danish and Norwegian shipping: ‘the national regime’ from the early 1960s to the mid-1970s; and ‘the competitive regime’, which was fully established by the middle of the 1990s and still persists. Then, we briefly sketch...... the bargaining that accompanied the shift from the national regime to the competitive regime. Specifically, we show that the new regime primarily accommodated the interests of private actors such as shipping companies, rather than the interests of the authorities and the trade unions....

  13. The CTBT regime, significance and potential benefits

    International Nuclear Information System (INIS)

    Chang, Hong-Lae

    2002-01-01

    This presentation briefly outlines the CTBT's background, describes the activities of the Preparatory Commission, the verification regime, the role of the National Data Centres and international coopereation. The objectives of the Nairobi workshop are listed

  14. Policy Regime Juxtaposition in Latin America

    Directory of Open Access Journals (Sweden)

    Kent Eaton

    2017-04-01

    Full Text Available This article has three main objectives, each in the spirit of broadening the study of subnational politics to include the juxtaposition of policy regimes and not just political regimes. First, it identifies the causes that help explain why we are seeing more territorial heterogeneity within countries in terms of the pursuit of ideologically disparate development models at different levels of government. Second, the article assesses the importance of this trend by analyzing the chief advantages and disadvantages of policy regime juxtaposition. Third, I turn to the question of why subnational officials are able to defend ideologically deviant policy regimes in some cases, but not in others. Based on the Bolivian, Ecuadorian, and Peruvian cases, my argument emphasizes the importance of two key factors: capacity and coalitions.

  15. The international climate regime: towards consolidation collapse

    International Nuclear Information System (INIS)

    Berthaud, P.; Cavard, D.; Criqui, P.

    2003-10-01

    This article deals with the different modalities that exist to manage a problem of collective action in the field of climate negotiation. It uses two concepts of the International Political Economy (IPE): the concept of International Regime (IR) and the concept of Hegemony and / or Leadership. The course the international negotiation has taken between 1992 (Rio Convention) and march 2001 (the US rejection of the Kyoto Protocol of 1997) leads us, first, to question the conditions of existence as well as the viability of a non-hegemonic International Regime (Part One). Then, we discuss the perspectives for the 'post - Kyoto' era. After having examined the preferences of the three most active actors in the negotiation (USA, Europe, G77 + China) combined with the leadership capacities they possess, we identify three scenarios for the future: i) anarchy, ii) an international regime under the American hegemony, iii) an international regime under the European leadership (Part Two). (author)

  16. Rates of fluvio-thermal erosion on Mars

    Science.gov (United States)

    Aguirre-Puente, J.; Costard, Francois M.; Posado-Cano, R.

    1993-01-01

    In order to get some ideas about the order of magnitude of fluvio-thermal recession rate, a mathematical thermal model for Martian outflow channels is proposed. This model corresponds to a system undergoing a permanent thermal regime where the surface temperature is constant and equal to the phase change temperature (due to the immediate removal of melted materials). This is an ablation model. For its application, estimations of the heat transfer coefficient h and thermal flux q are necessary. Determination of these coefficients needs the calculation of dimensionless numbers (Reynolds, Prandtl, and Nusselt), and the consideration of turbulent regime of the flow.

  17. Systems analysis of thermal storage

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, R. J.

    1980-08-01

    During FY80 analyses were conducted on thermal storage concepts for solar thermal applications. These studies include both estimates of the obtainable costs of thermal storage concepts and their worth to a user (i.e., value). Based on obtainable costs and performance, promising thermal storage concepts are being identified. A preliminary screening was completed in FY80 and a more in-depth study was initiated. Value studies are being conducted to establish cost goals. A ranking of storage concepts based on value in solar thermal electric plants was conducted for both diurnal and long duration applications. Ground mounted thermal storage concepts for a parabolic dish/Stirling systtem are also being evaluated.

  18. Authoritarian Regimes, Domestic Stability, and International Conflict

    OpenAIRE

    Bae, Joonbum

    2015-01-01

    This dissertation addresses the argument that there may not be room for cooperation in relations with (and in between) states with authoritarian systems of rule because international conflicts may strengthen their hold on power. To this end, it asks 1) whether authoritarian regimes benefit in terms of their duration in power from conflict, 2) whether conflicts stabilize domestic politics by moderating the violence involved during regime transitions (in terms of how they fall), and also 3) whe...

  19. Portfolio Selection with Jumps under Regime Switching

    Directory of Open Access Journals (Sweden)

    Lin Zhao

    2010-01-01

    Full Text Available We investigate a continuous-time version of the mean-variance portfolio selection model with jumps under regime switching. The portfolio selection is proposed and analyzed for a market consisting of one bank account and multiple stocks. The random regime switching is assumed to be independent of the underlying Brownian motion and jump processes. A Markov chain modulated diffusion formulation is employed to model the problem.

  20. Improving the taxation regime for electric power

    International Nuclear Information System (INIS)

    Fjermeros, Morten; Ilstad, Kristine

    2003-01-01

    In Norway, the present taxation regime for electric power is very complex. The power companies are currently charged with ordinary tax on profits, tax on economic rent, tax on natural resources and land tax. In addition there are the rules about licence fees, yield of power due to concession conditions, and reversion. The Norwegian Electricity Industry Association (EBL), assisted by a firm of lawyers, has proposed an improvement over the current taxation regime

  1. Brazil in the global anticorruption regime

    Directory of Open Access Journals (Sweden)

    Marcos Tourinho

    2018-03-01

    Full Text Available Abstract Brazilian anticorruption law and institutions were significantly transformed in recent decades. This article traces those transformations and explains how the international anticorruption and money laundering regimes contributed to their development. It argues that those international regimes were internalised in the Brazilian system through three mechanisms: inspiration and legitimation, coercion, and implementation support, and were critical to the transformation of Brazilian institutions.

  2. The Philippines: predatory regime, growing authoritarian features

    OpenAIRE

    Quimpo, Nathan Gilbert

    2009-01-01

    Over the past decade, and especially over the past few years, political corruption, fraud and violence in the Philippines have reached such alarming levels that many Filipinos have grown despondent, even cynical, about their country's political system. Exploring the suitability of the concepts of 'predatory state' and 'patrimonial oligarchic state' to the Philippines, I find that the regime rather than the state is the more appropriate unit of analysis. I argue that the predatory regime, cont...

  3. The initial regime of drop coalescence

    Science.gov (United States)

    Anthony, Christopher; Harris, Michael; Basaran, Osman

    2017-11-01

    Drop coalescence plays a key role in both industry and nature. Consequently, study of the phenomenon has been the focus of numerous experimental, computational and theoretical works to date. In coalescence, two drops come into contact and a liquid bridge forms between them. As time advances, this bridge grows from microscopic to macroscopic scales. Despite the large volume of work dedicated to this problem, currently experiment, theory, and computation are not in perfect agreement with respect to the earliest times following the initial contact of the drops. Experiments report an initial regime where the radius of the connecting bridge grows linearly in time before a transition to either a Stokes regime or an inertial regime where either viscous or inertial forces balance capillary force. In the initial linear regime, referred to as the inertially-limited viscous regime, all three forces are thought to be important. This is in contrast to theory which predicts that all coalescence events begin in the Stokes regime. We use high accuracy numerical simulation to show that the existing discrepancy in the literature can be resolved by paying careful attention to the initial conditions that set the shape and size of the bridge connecting the two drops.

  4. Electrical Subsurface Grounding Analysis

    International Nuclear Information System (INIS)

    J.M. Calle

    2000-01-01

    The purpose and objective of this analysis is to determine the present grounding requirements of the Exploratory Studies Facility (ESF) subsurface electrical system and to verify that the actual grounding system and devices satisfy the requirements

  5. Ultrafast Thermal Transport at Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Cahill, David [Univ. of Illinois, Champaign, IL (United States); Murphy, Catherine [Univ. of Illinois, Champaign, IL (United States); Martin, Lane [Univ. of Illinois, Champaign, IL (United States)

    2014-10-21

    Our research program on Ultrafast Thermal Transport at Interfaces advanced understanding of the mesoscale science of heat conduction. At the length and time scales of atoms and atomic motions, energy is transported by interactions between single-particle and collective excitations. At macroscopic scales, entropy, temperature, and heat are the governing concepts. Key gaps in fundamental knowledge appear at the transitions between these two regimes. The transport of thermal energy at interfaces plays a pivotal role in these scientific issues. Measurements of heat transport with ultrafast time resolution are needed because picoseconds are the fundamental scales where the lack of equilibrium between various thermal excitations becomes a important factor in the transport physics. A critical aspect of our work has been the development of experimental methods and model systems that enabled more precise and sensitive investigations of nanoscale thermal transport.

  6. Development of Fast and Reliable Free-Energy Density Functional Methods for Simulations of Dense Plasmas from Cold- to Hot-Temperature Regimes

    Science.gov (United States)

    Karasiev, V. V.

    2017-10-01

    Free-energy density functional theory (DFT) is one of the standard tools in high-energy-density physics used to determine the fundamental properties of dense plasmas, especially in cold and warm regimes when quantum effects are essential. DFT is usually implemented via the orbital-dependent Kohn-Sham (KS) procedure. There are two challenges of conventional implementation: (1) KS computational cost becomes prohibitively expensive at high temperatures; and (2) ground-state exchange-correlation (XC) functionals do not take into account the XC thermal effects. This talk will address both challenges and report details of the formal development of new generalized gradient approximation (GGA) XC free-energy functional which bridges low-temperature (ground state) and high-temperature (plasma) limits. Recent progress on development of functionals for orbital-free DFT as a way to address the second challenge will also be discussed. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  7. ASSESSING THE IMPORTANCE OF THERMAL REFUGE ...

    Science.gov (United States)

    Salmon populations require river networks that provide water temperature regimes sufficient to support a diversity of salmonid life histories across space and time. The importance of cold water refuges for migrating adult salmon and steelhead may seem intuitive, and refuges are clearly used by fish during warm water episodes. But quantifying the value of both small and large scale thermal features to salmon populations has been challenging due to the difficulty of mapping thermal regimes at sufficient spatial and temporal resolutions, and integrating thermal regimes into population models. We attempt to address these challenges by using newly-available datasets and modeling approaches to link thermal regimes to salmon populations across scales. We discuss the challenges and opportunities to simulating fish behaviors and linking exposures to migratory and reproductive fitness. In this talk and companion poster, we describe an individual-based modeling approach for assessing sufficiency of thermal refuges for migrating salmon and steelhead in the Columbia River. Many rivers and streams in the Pacific Northwest are currently listed as impaired under the Clean Water Act as a result of high summer water temperatures. Adverse effects of warm waters include impacts to salmon and steelhead populations that may already be stressed by habitat alteration, disease, predation, and fishing pressures. Much effort is being expended to improve conditions for salmon and steelhea

  8. Role of ground ice dynamics and ecological feedbacks in recent ice wedge degradation and stabilization

    Science.gov (United States)

    Mark Torre Jorgenson,; Mikhail Kanevskiy,; Yuri Shur,; Natalia Moskalenko,; Dana Brown,; Wickland, Kimberly P.; Striegl, Robert G.; Koch, Joshua C.

    2015-01-01

    Ground ice is abundant in the upper permafrost throughout the Arctic and fundamentally affects terrain responses to climate warming. Ice wedges, which form near the surface and are the dominant type of massive ice in the Arctic, are particularly vulnerable to warming. Yet processes controlling ice wedge degradation and stabilization are poorly understood. Here we quantified ice wedge volume and degradation rates, compared ground ice characteristics and thermal regimes across a sequence of five degradation and stabilization stages and evaluated biophysical feedbacks controlling permafrost stability near Prudhoe Bay, Alaska. Mean ice wedge volume in the top 3 m of permafrost was 21%. Imagery from 1949 to 2012 showed thermokarst extent (area of water-filled troughs) was relatively small from 1949 (0.9%) to 1988 (1.5%), abruptly increased by 2004 (6.3%) and increased slightly by 2012 (7.5%). Mean annual surface temperatures varied by 4.9°C among degradation and stabilization stages and by 9.9°C from polygon center to deep lake bottom. Mean thicknesses of the active layer, ice-poor transient layer, ice-rich intermediate layer, thermokarst cave ice, and wedge ice varied substantially among stages. In early stages, thaw settlement caused water to impound in thermokarst troughs, creating positive feedbacks that increased net radiation, soil heat flux, and soil temperatures. Plant growth and organic matter accumulation in the degraded troughs provided negative feedbacks that allowed ground ice to aggrade and heave the surface, thus reducing surface water depth and soil temperatures in later stages. The ground ice dynamics and ecological feedbacks greatly complicate efforts to assess permafrost responses to climate change.

  9. Role of ground ice dynamics and ecological feedbacks in recent ice wedge degradation and stabilization

    Science.gov (United States)

    Jorgenson, M. T.; Kanevskiy, M.; Shur, Y.; Moskalenko, N.; Brown, D. R. N.; Wickland, K.; Striegl, R.; Koch, J.

    2015-11-01

    Ground ice is abundant in the upper permafrost throughout the Arctic and fundamentally affects terrain responses to climate warming. Ice wedges, which form near the surface and are the dominant type of massive ice in the Arctic, are particularly vulnerable to warming. Yet processes controlling ice wedge degradation and stabilization are poorly understood. Here we quantified ice wedge volume and degradation rates, compared ground ice characteristics and thermal regimes across a sequence of five degradation and stabilization stages and evaluated biophysical feedbacks controlling permafrost stability near Prudhoe Bay, Alaska. Mean ice wedge volume in the top 3 m of permafrost was 21%. Imagery from 1949 to 2012 showed thermokarst extent (area of water-filled troughs) was relatively small from 1949 (0.9%) to 1988 (1.5%), abruptly increased by 2004 (6.3%) and increased slightly by 2012 (7.5%). Mean annual surface temperatures varied by 4.9°C among degradation and stabilization stages and by 9.9°C from polygon center to deep lake bottom. Mean thicknesses of the active layer, ice-poor transient layer, ice-rich intermediate layer, thermokarst cave ice, and wedge ice varied substantially among stages. In early stages, thaw settlement caused water to impound in thermokarst troughs, creating positive feedbacks that increased net radiation, soil heat flux, and soil temperatures. Plant growth and organic matter accumulation in the degraded troughs provided negative feedbacks that allowed ground ice to aggrade and heave the surface, thus reducing surface water depth and soil temperatures in later stages. The ground ice dynamics and ecological feedbacks greatly complicate efforts to assess permafrost responses to climate change.

  10. The ground based plan

    International Nuclear Information System (INIS)

    1989-01-01

    The paper presents a report of ''The Ground Based Plan'' of the United Kingdom Science and Engineering Research Council. The ground based plan is a plan for research in astronomy and planetary science by ground based techniques. The contents of the report contains a description of:- the scientific objectives and technical requirements (the basis for the Plan), the present organisation and funding for the ground based programme, the Plan, the main scientific features and the further objectives of the Plan. (U.K.)

  11. Constructivist Grounded Theory?

    OpenAIRE

    Glaser, Barney G.

    2007-01-01

    In meinem Beitrag greife ich zurück auf den ausgezeichneten und inspirierenden Artikel von CHARMAZ zu konstruktivistischer Grounded Theory, um an diesem Beispiel zu diskutieren, dass und warum die Grounded Theory kein konstruktivistisches Unterfangen ist. Ich versuche zu zeigen, dass "konstruktivistische Daten" bzw. konstruktivistische Anwendungen der Grounded Theory, sofern sie überhaupt existieren bzw. sinnvoll sein könnten, nur einen verschwindend kleinen Teil der Grounded Theory ausmachen...

  12. Thermal comfort

    CSIR Research Space (South Africa)

    Osburn, L

    2010-01-01

    Full Text Available wider range of temperature limits, saving energy while still satisfying the majority of building occupants. It is also noted that thermal comfort varies significantly between individuals and it is generally not possible to provide a thermal environment...

  13. Thermal entanglement properties of small spin clusters

    OpenAIRE

    Bose, Indrani; Tribedi, Amit

    2005-01-01

    Exchange interactions in spin systems can give rise to quantum entanglement in the ground and thermal states of the systems. In this paper, we consider a spin tetramer, with spins of magnitude 1/2, in which the spins interact via nearest-neighbour, diagonal and four-spin interactions of strength J1, J2 and K respectively. The ground and thermal state entanglement properties of the tetramer are calculated analytically in the various limiting cases. Signatures of quantum phase transition (QPT) ...

  14. Communication, concepts and grounding

    NARCIS (Netherlands)

    van der Velde, Frank; van der Velde, F.

    2015-01-01

    This article discusses the relation between communication and conceptual grounding. In the brain, neurons, circuits and brain areas are involved in the representation of a concept, grounding it in perception and action. In terms of grounding we can distinguish between communication within the brain

  15. Ecosystem regime shifts disrupt trophic structure.

    Science.gov (United States)

    Hempson, Tessa N; Graham, Nicholas A J; MacNeil, M Aaron; Hoey, Andrew S; Wilson, Shaun K

    2018-01-01

    Regime shifts between alternative stable ecosystem states are becoming commonplace due to the combined effects of local stressors and global climate change. Alternative states are characterized as substantially different in form and function from pre-disturbance states, disrupting the delivery of ecosystem services and functions. On coral reefs, regime shifts are typically characterized by a change in the benthic composition from coral to macroalgal dominance. Such fundamental shifts in the benthos are anticipated to impact associated fish communities that are reliant on the reef for food and shelter, yet there is limited understanding of how regime shifts propagate through the fish community over time, relative to initial or recovery conditions. This study addresses this knowledge gap using long-term data of coral reef regime shifts and recovery on Seychelles reefs following the 1998 mass bleaching event. It shows how trophic structure of the reef fish community becomes increasingly dissimilar between alternative reef ecosystem states (regime-shifted vs. recovering) with time since disturbance. Regime-shifted reefs developed a concave trophic structure, with increased biomass in base trophic levels as herbivorous species benefitted from increased algal resources. Mid trophic level species, including specialists such as corallivores, declined with loss of coral habitat, while biomass was retained in upper trophic levels by large-bodied, generalist invertivores. Recovering reefs also experienced an initial decline in mid trophic level biomass, but moved toward a bottom-heavy pyramid shape, with a wide range of feeding groups (e.g., planktivores, corallivores, omnivores) represented at mid trophic levels. Given the importance of coral reef fishes in maintaining the ecological function of coral reef ecosystems and their associated fisheries, understanding the effects of regime shifts on these communities is essential to inform decisions that enhance ecological

  16. Computational study of collisions between O(3P) and NO(2Π) at temperatures relevant to the hypersonic flight regime.

    Science.gov (United States)

    Castro-Palacio, Juan Carlos; Nagy, Tibor; Bemish, Raymond J; Meuwly, Markus

    2014-10-28

    Reactions involving N and O atoms dominate the energetics of the reactive air flow around spacecraft when reentering the atmosphere in the hypersonic flight regime. For this reason, the thermal rate coefficients for reactive processes involving O((3)P) and NO((2)Π) are relevant over a wide range of temperatures. For this purpose, a potential energy surface (PES) for the ground state of the NO2 molecule is constructed based on high-level ab initio calculations. These ab initio energies are represented using the reproducible kernel Hilbert space method and Legendre polynomials. The global PES of NO2 in the ground state is constructed by smoothly connecting the surfaces of the grids of various channels around the equilibrium NO2 geometry by a distance-dependent weighting function. The rate coefficients were calculated using Monte Carlo integration. The results indicate that at high temperatures only the lowest A-symmetry PES is relevant. At the highest temperatures investigated (20,000 K), the rate coefficient for the "O1O2+N" channel becomes comparable (to within a factor of around three) to the rate coefficient of the oxygen exchange reaction. A state resolved analysis shows that the smaller the vibrational quantum number of NO in the reactants, the higher the relative translational energy required to open it and conversely with higher vibrational quantum number, less translational energy is required. This is in accordance with Polanyi's rules. However, the oxygen exchange channel (NO2+O1) is accessible at any collision energy. Finally, this work introduces an efficient computational protocol for the investigation of three-atom collisions in general.

  17. Analysis of possibilities for functional capacity for work rise of reactor fuel elements at nuclear engine regime

    International Nuclear Information System (INIS)

    Deryavko, I.I.; Perepelkin, I.G.; Pivovarov, O.S.; Storozhenko, A.N.; Tarasov, V.I.

    2000-01-01

    The principle results of carbide fuel rods testing during series of IVG.1 reactor starts up at regime simulating nuclear engine regime of nuclear moving power unit are given. Considerable degradation of initial fuel elements status increasing from start up to start up and which could resulted fail of separate technological channels is shown. Origin case of extreme degradation of fuel elements status are insufficient thermal strength of fuel elements operation in the field brittle state of sintered carbide material, Possible ways of artificial reinforce of fuel elements of low temperature sections, increasing its thermal strength up to required level

  18. Thermal Ignition

    Science.gov (United States)

    Boettcher, Philipp Andreas

    Accidental ignition of flammable gases is a critical safety concern in many industrial applications. Particularly in the aviation industry, the main areas of concern on an aircraft are the fuel tank and adjoining regions, where spilled fuel has a high likelihood of creating a flammable mixture. To this end, a fundamental understanding of the ignition phenomenon is necessary in order to develop more accurate test methods and standards as a means of designing safer air vehicles. The focus of this work is thermal ignition, particularly auto-ignition with emphasis on the effect of heating rate, hot surface ignition and flame propagation, and puffing flames. Combustion of hydrocarbon fuels is traditionally separated into slow reaction, cool flame, and ignition regimes based on pressure and temperature. Standard tests, such as the ASTM E659, are used to determine the lowest temperature required to ignite a specific fuel mixed with air at atmospheric pressure. It is expected that the initial pressure and the rate at which the mixture is heated also influences the limiting temperature and the type of combustion. This study investigates the effect of heating rate, between 4 and 15 K/min, and initial pressure, in the range of 25 to 100 kPa, on ignition of n-hexane air mixtures. Mixtures with equivalence ratio ranging from 0.6 to 1.2 were investigated. The problem is also modeled computationally using an extension of Semenov's classical auto-ignition theory with a detailed chemical mechanism. Experiments and simulations both show that in the same reactor either a slow reaction or an ignition event can take place depending on the heating rate. Analysis of the detailed chemistry demonstrates that a mixture which approaches the ignition region slowly undergoes a significant modification of its composition. This change in composition induces a progressive shift of the explosion limit until the mixture is no longer flammable. A mixture that approaches the ignition region

  19. Actual evapotranspiration, root extraction, water regime and productivity in the case of lucerne

    International Nuclear Information System (INIS)

    Rambal, S.; Berger, A.; Parisot, J.M.

    1983-01-01

    Measurements were made of the actual evaportranspiration, root extraction and above-ground yield in the case of two varieties of lucerne Medicago sativa L. - Du Puits and Polder - and mixtures of them in equal parts. The daily kinetics of the water potential of the leaves and the collar show that the water regimes of the two varieties are identical in a first approximation. The root systems are different. Polder has the deeper system. The regime of the binary mixture is not simply a juxtaposition of the regimes of the constitutents. Two types of non-linearity were found. The first relates to water flow and the second to productivity. It is postulated that the root systems of the two varieties constituting the mixture undergo plastic deformation, leading to a more efficient resultant system. A system of this type needs, on the other hand, an allocation of photosynthates that would affect its productivity. (author)

  20. Negative mobility of a Brownian particle: Strong damping regime

    Science.gov (United States)

    Słapik, A.; Łuczka, J.; Spiechowicz, J.

    2018-02-01

    We study impact of inertia on directed transport of a Brownian particle under non-equilibrium conditions: the particle moves in a one-dimensional periodic and symmetric potential, is driven by both an unbiased time-periodic force and a constant force, and is coupled to a thermostat of temperature T. Within selected parameter regimes this system exhibits negative mobility, which means that the particle moves in the direction opposite to the direction of the constant force. It is known that in such a setup the inertial term is essential for the emergence of negative mobility and it cannot be detected in the limiting case of overdamped dynamics. We analyse inertial effects and show that negative mobility can be observed even in the strong damping regime. We determine the optimal dimensionless mass for the presence of negative mobility and reveal three mechanisms standing behind this anomaly: deterministic chaotic, thermal noise induced and deterministic non-chaotic. The last origin has never been reported. It may provide guidance to the possibility of observation of negative mobility for strongly damped dynamics which is of fundamental importance from the point of view of biological systems, all of which in situ operate in fluctuating environments.

  1. Satellite laser ranging in the near-infrared regime

    Science.gov (United States)

    Eckl, Johann J.; Schreiber, K. Ulrich; Schüler, Torben

    2017-05-01

    Satellite Laser Ranging Systems typically operate on the second harmonic wavelength of a pulsed Nd:YAG laser at a wavelength of 532 nm. The absence of sufficiently sensitive photo-detectors with a reasonably large active area made it beneficial to trade the conversion loss of frequency doubling against the higher quantum efficiency of the detectors. Solid state silicon detectors in the near infra-red regime at λ = 1.064 µm also suffered from high thermal noise and slow signal rise times, which increased the scatter of the measurements by more than a factor of 3 over the operation at λ = 532 nm. With the availability of InGaAs/InP compound - Single Photon Avalanche Diodes the situation has changed considerably. Their quantum efficiency has reached 70% and the compound material of these diodes provides a response bandwidth, which is commensurate with high high speed detectors in the regime of 532 nm. We have investigated the properties of such a diode type Princeton Lightwave PGA-200-1064 for its suitability for SLR at the Nd:YAG fundamental wavelength with respect to the quantum efficiency and their timing properties. The results are presented in this paper. Furthermore, we provide remarks to on the performance of the diode compared to state of the art detectors, that operate at the Nd:YAG second harmonic wavelength. Finally, we give an estimate of the photoelectron statistics in satellite laser ranging for different operational parameters of the Wettzell Laser Ranging System.

  2. Hypersonic Inflatable Aerodynamic Decelerator Ground Test Development

    Science.gov (United States)

    Del Corso, Jospeh A.; Hughes, Stephen; Cheatwood, Neil; Johnson, Keith; Calomino, Anthony

    2015-01-01

    Hypersonic Inflatable Aerodynamic Decelerator (HIAD) technology readiness levels have been incrementally matured by NASA over the last thirteen years, with most recent support from NASA's Space Technology Mission Directorate (STMD) Game Changing Development Program (GCDP). Recently STMD GCDP has authorized funding and support through fiscal year 2015 (FY15) for continued HIAD ground developments which support a Mars Entry, Descent, and Landing (EDL) study. The Mars study will assess the viability of various EDL architectures to enable a Mars human architecture pathfinder mission planned for mid-2020. At its conclusion in November 2014, NASA's first HIAD ground development effort had demonstrated success with fabricating a 50 W/cm2 modular thermal protection system, a 400 C capable inflatable structure, a 10-meter scale aeroshell manufacturing capability, together with calibrated thermal and structural models. Despite the unquestionable success of the first HIAD ground development effort, it was recognized that additional investment was needed in order to realize the full potential of the HIAD technology capability to enable future flight opportunities. The second HIAD ground development effort will focus on extending performance capability in key technology areas that include thermal protection system, lifting-body structures, inflation systems, flight control, stage transitions, and 15-meter aeroshell scalability. This paper presents an overview of the accomplishments under the baseline HIAD development effort and current plans for a follow-on development effort focused on extending those critical technologies needed to enable a Mars Pathfinder mission.

  3. Rigour and grounded theory.

    Science.gov (United States)

    Cooney, Adeline

    2011-01-01

    This paper explores ways to enhance and demonstrate rigour in a grounded theory study. Grounded theory is sometimes criticised for a lack of rigour. Beck (1993) identified credibility, auditability and fittingness as the main standards of rigour for qualitative research methods. These criteria were evaluated for applicability to a Straussian grounded theory study and expanded or refocused where necessary. The author uses a Straussian grounded theory study (Cooney, In press) to examine how the revised criteria can be applied when conducting a grounded theory study. Strauss and Corbin (1998b) criteria for judging the adequacy of a grounded theory were examined in the context of the wider literature examining rigour in qualitative research studies in general and grounded theory studies in particular. A literature search for 'rigour' and 'grounded theory' was carried out to support this analysis. Criteria are suggested for enhancing and demonstrating the rigour of a Straussian grounded theory study. These include: cross-checking emerging concepts against participants' meanings, asking experts if the theory 'fit' their experiences, and recording detailed memos outlining all analytical and sampling decisions. IMPLICATIONS FOR RESEARCH PRACTICE: The criteria identified have been expressed as questions to enable novice researchers to audit the extent to which they are demonstrating rigour when writing up their studies. However, it should not be forgotten that rigour is built into the grounded theory method through the inductive-deductive cycle of theory generation. Care in applying the grounded theory methodology correctly is the single most important factor in ensuring rigour.

  4. Applying Petroleum the Pressure Buildup Well Test Procedure on Thermal Response Test—A Novel Method for Analyzing Temperature Recovery Period

    Directory of Open Access Journals (Sweden)

    Tomislav Kurevija

    2018-02-01

    Full Text Available The theory of Thermal Response Testing (TRT is a well-known part of the sizing process of the geothermal exchange system. Multiple parameters influence the accuracy of effective ground thermal conductivity measurement; like testing time, variable power, climate interferences, groundwater effect, etc. To improve the accuracy of the TRT, we introduced a procedure to additionally analyze falloff temperature decline after the power test. The method is based on a premise of analogy between TRT and petroleum well testing, since the origin of both procedures lies in the diffusivity equation with solutions for heat conduction or pressure analysis during radial flow. Applying pressure build-up test interpretation techniques to borehole heat exchanger testing, greater accuracy could be achieved since ground conductivity could be obtained from this period. Analysis was conducted on a coaxial exchanger with five different power steps, and with both direct and reverse flow regimes. Each test was set with 96 h of classical TRT, followed by 96 h of temperature decline, making for almost 2000 h of cumulative borehole testing. Results showed that the ground conductivity value could vary by as much as 25%, depending on test time, seasonal period and power fluctuations, while the thermal conductivity obtained from the falloff period provided more stable values, with only a 10% value variation.

  5. Development of a Compact, Deep-Penetrating Heat Flow Instrument for Lunar Landers: In-Situ Thermal Conductivity System

    Science.gov (United States)

    Nagihara, S.; Zacny, K.; Hedlund, M.; Taylor, P. T.

    2012-01-01

    Geothermal heat flow is obtained as a product of the geothermal gradient and the thermal conductivity of the vertical soil/rock/regolith interval penetrated by the instrument. Heat flow measurements are a high priority for the geophysical network missions to the Moon recommended by the latest Decadal Survey and previously the International Lunar Network. One of the difficulties associated with lunar heat flow measurement on a robotic mission is that it requires excavation of a relatively deep (approx 3 m) hole in order to avoid the long-term temporal changes in lunar surface thermal environment affecting the subsurface temperature measurements. Such changes may be due to the 18.6-year-cylcle lunar precession, or may be initiated by presence of the lander itself. Therefore, a key science requirement for heat flow instruments for future lunar missions is to penetrate 3 m into the regolith and to measure both thermal gradient and thermal conductivity. Engineering requirements are that the instrument itself has minimal impact on the subsurface thermal regime and that it must be a low-mass and low-power system like any other science instrumentation on planetary landers. It would be very difficult to meet the engineering requirements, if the instrument utilizes a long (> 3 m) probe driven into the ground by a rotary or percussive drill. Here we report progress in our efforts to develop a new, compact lunar heat flow instrumentation that meets all of these science and engineering requirements.

  6. Progress towards a global nuclear liability regime

    International Nuclear Information System (INIS)

    2014-01-01

    During its April 2014 meeting, the Steering Committee for Nuclear Energy held a policy debate on 'Progress towards a Global Nuclear Liability Regime'. The Steering Committee heard presentations from several experts on nuclear liability issues. To prepare the delegates to the Steering Committee for the policy debate, the NEA Secretariat prepared a background note on the status of the nuclear liability regimes, as well as on current issues and challenges in implementing the regimes. This article is based on the background note and is intended to provide basic information on the relevant international conventions and an overview of recent developments to enhance the understanding of the legal framework in which policy-makers and practitioners are engaging to respond to the call for broader adherence to the international liability instruments. (authors)

  7. Multiscale regime shifts and planetary boundaries.

    Science.gov (United States)

    Hughes, Terry P; Carpenter, Stephen; Rockström, Johan; Scheffer, Marten; Walker, Brian

    2013-07-01

    Life on Earth has repeatedly displayed abrupt and massive changes in the past, and there is no reason to expect that comparable planetary-scale regime shifts will not continue in the future. Different lines of evidence indicate that regime shifts occur when the climate or biosphere transgresses a tipping point. Whether human activities will trigger such a global event in the near future is uncertain, due to critical knowledge gaps. In particular, we lack understanding of how regime shifts propagate across scales, and whether local or regional tipping points can lead to global transitions. The ongoing disruption of ecosystems and climate, combined with unprecedented breakdown of isolation by human migration and trade, highlights the need to operate within safe planetary boundaries. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Constant diurnal temperature regime alters the impact of simulated climate warming on a tropical pseudoscorpion.

    Science.gov (United States)

    Zeh, Jeanne A; Bonilla, Melvin M; Su, Eleanor J; Padua, Michael V; Anderson, Rachel V; Zeh, David W

    2014-01-15

    Recent theory suggests that global warming may be catastrophic for tropical ectotherms. Although most studies addressing temperature effects in ectotherms utilize constant temperatures, Jensen's inequality and thermal stress considerations predict that this approach will underestimate warming effects on species experiencing daily temperature fluctuations in nature. Here, we tested this prediction in a neotropical pseudoscorpion. Nymphs were reared in control and high-temperature treatments under a constant daily temperature regime, and results compared to a companion fluctuating-temperature study. At constant temperature, pseudoscorpions outperformed their fluctuating-temperature counterparts. Individuals were larger, developed faster, and males produced more sperm, and females more embryos. The greatest impact of temperature regime involved short-term, adult exposure, with constant temperature mitigating high-temperature effects on reproductive traits. Our findings demonstrate the importance of realistic temperature regimes in climate warming studies, and suggest that exploitation of microhabitats that dampen temperature oscillations may be critical in avoiding extinction as tropical climates warm.

  9. Causas estruturais e consequências dos regimes internacionais: regimes como variáveis intervenientes

    Directory of Open Access Journals (Sweden)

    Stephen D. Krasner

    2012-06-01

    Full Text Available Os regimes internacionais são definidos como princípios, normas, regras e procedimentos de tomada de decisões ao redor dos quais as expectativas dos atores convergem em uma dada área-tema. Como ponto de partida, os regimes são conceituados como variáveis intervenientes, estando entre fatores causais básicos e os resultados e comportamentos relacionados. Há três visões a respeito da importância dos regimes: as orientações estruturais convencionais desvalorizam os regimes como sendo, na melhor das hipóteses, ineficazes; as orientações grocianas vêem os regimes como componentes íntimos do sistema internacional; as perspectivas estruturalistas modificadas vêem os regimes como significativos somente em certas condições restritas. Para os argumentos grociano e estruturalista modificado - que concordam com a visão de que os regimes podem influenciar resultados e comportamentos - , o desenvolvimento de regimes é visto como uma função de cinco variáveis causais básicas: auto-interesse egoísta; poder político; normas e princípios difusos; usos e costumes; conhecimento.

  10. Fire regimes during the last glacial

    Science.gov (United States)

    Daniau, A.; Harrison, S. P.; Bartlein, P. J.

    2009-12-01

    Fire regimes during the last glacial A.-L. Daniau (1), S.P. Harrison (1) and P.J. Bartlein (2) (1) School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK (2) Department of Geography, University of Oregon, Eugene, OR 97403, USA Sedimentary charcoal records document changes in fire regime. We have identified 67 sites which have records for some part of the last glacial and have used the 30 of these sites with better-than millennial-resolution to analyse changes in global fire regimes. Fire was consistently lower during the glacial than during the Eemian and Holocene. Within the glacial, Marine Isotope Stage (MIS) 3 is characterised globally by more fire than MIS 2. The signal for MIS 4 is less clear: there is more fire in the northern hemisphere and less fire in the southern hemisphere than during MIS 2 and 3. The records, most particularly records from the northern extratropics, show millennial-scale variability in fire regimes corresponding to the rapid climate changes associated with Dansgaard-Oeschger (D-O) cycles. Most of the D-O cycles during the last glacial and all of the Heinrich Stadials are apparent in the composite global record of the high-resolution sites: fire increases during D-O warming events and decreases during intervals of cooling. Our analyses show that fire regimes show a lagged response to rapid climate changes of ca 100-200 years in the case of D-O warming events, ca 0-100 years in the case of D-O cooling events and ca 200 years in the case of Heinrich Stadials. The strong climatic variability experienced during the glacial resulted in important changes in fire regimes even though the base level of biomass burning was less than today.

  11. Performance Analysis of Slinky Horizontal Ground Heat Exchangers for a Ground Source Heat Pump System

    Directory of Open Access Journals (Sweden)

    Md. Hasan Ali

    2017-10-01

    Full Text Available This paper highlights the thermal performance of reclined (parallel to ground surface and standing (perpendicular to ground surface slinky horizontal ground heat exchangers (HGHEs with different water mass flow rates in the heating mode of continuous and intermittent operations. A copper tube with an outer surface protected with low-density polyethylene was selected as the tube material of the ground heat exchanger. Effects on ground temperature around the reclined slinky HGHE due to heat extraction and the effect of variation of ground temperatures on reclined HGHE performance are discussed. A higher heat exchange rate was experienced in standing HGHE than in reclined HGHE. The standing HGHE was affected by deeper ground temperature and also a greater amount of backfilled sand in standing HGHE (4.20 m3 than reclined HGHE (1.58 m3, which has higher thermal conductivity than site soil. For mass flow rate of 1 L/min with inlet water temperature 7 °C, the 4-day average heat extraction rates increased 45.3% and 127.3%, respectively, when the initial average ground temperatures at 1.5 m depth around reclined HGHE increased from 10.4 °C to 11.7 °C and 10.4 °C to 13.7 °C. In the case of intermittent operation, which boosted the thermal performance, a short time interval of intermittent operation is better than a long time interval of intermittent operation. Furthermore, from the viewpoint of power consumption by the circulating pump, the intermittent operation is more efficient than continuous operation.

  12. Longevity of Emplacement Drift Ground Support Materials

    International Nuclear Information System (INIS)

    Tang, D.

    2000-01-01

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for selection of materials for ground support that will function throughout the preclosure period. The Development Plan (DP) for this analysis is given in CRWMS M and O (Civilian Radioactive Waste Management System Management and Operating Contractor) (1999a). The candidate materials for ground support are steel (carbon steel, ductile cast iron, galvanized steel, and stainless steel, etc.) and cement. Steel will mainly be used for steel sets, lagging, channels, rock bolts, and wire mesh. Cement usage is only considered in the case of grouted rock bolts. The candidate materials for the invert structure are steel and crushed rock ballast. The materials shall be evaluated for the repository emplacement drift environment under a specific thermal loading condition based on the proposed License Application Design Selection (LADS) design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground control materials for use in emplacement drifts. (2) Review existing documents concerning behavior of candidate ground control materials during the preclosure period. The major criteria to be considered for steel are mechanical and thermal properties, and durability, of which corrosion is the most important concern. (3) Evaluate the available results and develop recommendations for material(s) to be used

  13. WELFARE REGIMES IN LATIN AMERICA AND CARIBBEAN

    Directory of Open Access Journals (Sweden)

    Melisa Campana-Alabarce

    2015-06-01

    Full Text Available This article provides a characterization of Latin American and Caribbean Welfare regimes in historiographical perspective. Firstly, it makes a review of the emergence conditions of Welfare States in Western Europe and its core features, with particular emphasis on its role as a method to regulate inequalities in industrial capitalism. Dialoguing with it, then stops in the specific configurations that welfare regimes have taken in Latin America during the course of the twentieth century. Finally, it provides a map of its contemporary features and the major challenges that the States of the region face in his capacity as right guarantors for the future.

  14. The oil tax regime of Azerbaijan

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Gerard

    1998-07-01

    Azerbaijan has a long history in the oil business and a chance of a spectacular future. To understand why the oil tax regime evolved into its present form and how it is likely to develop, it is necessary to know something of the country's history and the commercial environment. Consequently the presentation begins by discussing these items. It then outlines the Production Sharing Agreement regime in Azerbaijan and then deals with the Kazakh and Georgian Tax Codes, as these are likely to be the basis of a new general tax law in Azerbaijan from 1999. The presentation includes comments on the New Draft Tax Code of 1998.

  15. Legal Regimes of Official Information in Ukraine

    Directory of Open Access Journals (Sweden)

    Serhii Yesimov

    2018-04-01

    Full Text Available In the article on the basis of the methodology of system analysis the legal nature and sources of legal regulation of the legal regime of official information in Ukraine in the conditions of adaptation of Ukrainian legislation to the legislation of the European Union are considered. A comparative legal analysis of official information in the public-law and private-law spheres in the context of legal regimes of restricted information, confidential information and information classified as state secrets has been conducted.

  16. Statistical regimes of random laser fluctuations

    International Nuclear Information System (INIS)

    Lepri, Stefano; Cavalieri, Stefano; Oppo, Gian-Luca; Wiersma, Diederik S.

    2007-01-01

    Statistical fluctuations of the light emitted from amplifying random media are studied theoretically and numerically. The characteristic scales of the diffusive motion of light lead to Gaussian or power-law (Levy) distributed fluctuations depending on external control parameters. In the Levy regime, the output pulse is highly irregular leading to huge deviations from a mean-field description. Monte Carlo simulations of a simplified model which includes the population of the medium demonstrate the two statistical regimes and provide a comparison with dynamical rate equations. Different statistics of the fluctuations helps to explain recent experimental observations reported in the literature

  17. Regimes of flow past a vortex generator

    DEFF Research Database (Denmark)

    Velte, Clara Marika; Okulov, V.L.; Naumov, I.V.

    2012-01-01

    A complete parametric investigation of the development of multi-vortex regimes in a wake past simple vortex generator has been carried out. It is established that the vortex structure in the wake is much more complicated than a simple monopole tip vortex. The vortices were studied by stereoscopic...... particle image velocimetry (SPIV). Based on the obtained SPIV data, a map of the regimes of flow past the vortex generator has been constructed. One region with a developed stable multivortex system on this map reaches the vicinity of the optimum angle of attack of the vortex generator....

  18. Towards a Global Regime of Higher Education

    Directory of Open Access Journals (Sweden)

    Paolo Do

    2015-12-01

    Full Text Available This paper rethinks the spatialization of educational institutions at the global level, scaling and rescaling the space of the university as an inclusive process that makes academic knowledge production something heterogeneous, complex and composite, and proposing a regime for the higher education system based on a stratified relationship that is asymmetrical and geographically displaced. Moreover it outlines the “new” political economy of knowledge, which is a particular mechanism in contemporary capitalist production, capable of creating an artificial scarcity of knowledge by means of hierarchies, and reproducing the classical law of value in a regime based on abundance instead of scarcity.

  19. Flocking regimes in a simple lattice model.

    Science.gov (United States)

    Raymond, J R; Evans, M R

    2006-03-01

    We study a one-dimensional lattice flocking model incorporating all three of the flocking criteria proposed by Reynolds [Computer Graphics 21, 4 (1987)]: alignment, centering, and separation. The model generalizes that introduced by O. J. O'Loan and M. R. Evans [J. Phys. A. 32, L99 (1999)]. We motivate the dynamical rules by microscopic sampling considerations. The model exhibits various flocking regimes: the alternating flock, the homogeneous flock, and dipole structures. We investigate these regimes numerically and within a continuum mean-field theory.

  20. Computational characterization of ignition regimes in a syngas/air mixture with temperature fluctuations

    KAUST Repository

    Pal, Pinaki

    2016-07-27

    Auto-ignition characteristics of compositionally homogeneous reactant mixtures in the presence of thermal non-uniformities and turbulent velocity fluctuations were computationally investigated. The main objectives were to quantify the observed ignition characteristics and numerically validate the theory of the turbulent ignition regime diagram recently proposed by Im et al. 2015 [29] that provides a framework to predict ignition behavior . a priori based on the thermo-chemical properties of the reactant mixture and initial flow and scalar field conditions. Ignition regimes were classified into three categories: . weak (where deflagration is the dominant mode of fuel consumption), . reaction-dominant strong, and . mixing-dominant strong (where volumetric ignition is the dominant mode of fuel consumption). Two-dimensional (2D) direct numerical simulations (DNS) of auto-ignition in a lean syngas/air mixture with uniform mixture composition at high-pressure, low-temperature conditions were performed in a fixed volume. The initial conditions considered two-dimensional isotropic velocity spectrums, temperature fluctuations and localized thermal hot spots. A number of parametric test cases, by varying the characteristic turbulent Damköhler and Reynolds numbers, were investigated. The evolution of the auto-ignition phenomena, pressure rise, and heat release rate were analyzed. In addition, combustion mode analysis based on front propagation speed and computational singular perturbation (CSP) was applied to characterize the auto-ignition phenomena. All results supported that the observed ignition behaviors were consistent with the expected ignition regimes predicted by the theory of the regime diagram. This work provides new high-fidelity data on syngas ignition characteristics over a broad range of conditions and demonstrates that the regime diagram serves as a predictive guidance in the understanding of various physical and chemical mechanisms controlling auto

  1. The US and India Security-Economic Dilemma: A Study on the Effects of Relative Gain Sensitivities and Regime Formation

    Science.gov (United States)

    2014-05-01

    New York: Norton, 2001), 55. 5 Robert Gilpin , War and Change in World Politics, (Cambridge; New York: Cambridge University Press, 1981), 40. 6 For... Robert Gilpin as system, systemic, and interaction that occur within those areas.18 The types of change provide common ground for both theories to rest...significantly influences the development and sustainment of a regime. 18 Robert Gilpin , War and

  2. Thermal Characteristics of Urban Landscapes

    Science.gov (United States)

    Luvall, Jeffrey C.; Quattrochi, Dale A.

    1998-01-01

    Although satellite data are very useful for analysis of the urban heat island effect at a coarse scale, they do not lend themselves to developing a better understanding of which surfaces across the city contribute or drive the development of the urban heat island effect. Analysis of thermal energy responses for specific or discrete surfaces typical of the urban landscape (e.g., asphalt, building rooftops, vegetation) requires measurements at a very fine spatial scale (i.e., less than 15 m) to adequately resolve these surfaces and their attendant thermal energy regimes. Additionally, very fine scale spatial resolution thermal infrared data, such as that obtained from aircraft, are very useful for demonstrating to planning officials, policy makers, and the general populace the benefits of the urban forest. These benefits include mitigating the urban heat island effect, making cities more aesthetically pleasing and more habitable environments, and aid in overall cooling of the community. High spatial resolution thermal data are required to quantify how artificial surfaces within the city contribute to an increase in urban heating and the benefit of cool surfaces (e.g., surface coatings that reflect much of the incoming solar radiation as opposed to absorbing it thereby lowering urban temperatures). The TRN (thermal response number) is a technique using aircraft remotely sensed surface temperatures to quantify the thermal response of urban surfaces. The TRN was used to quantify the thermal response of various urban surface types ranging from completely vegetated surfaces to asphalt and concrete parking lots for Huntsville, AL.

  3. Human impacts on river ice regime in the Carpathian Basin

    Science.gov (United States)

    Takács, Katalin; Nagy, Balázs; Kern, Zoltán

    2014-05-01

    River ice is a very important component of the cryosphere, and is especially sensitive to climatic variability. Historical records of appearance or disappearance and timing of ice phenomena are useful indicators for past climatic variations (Williams, 1970). Long-term observations of river ice freeze-up and break-up dates are available for many rivers in the temperate or cold region to detect and analyze the effects of climate change on river ice regime. The ice regime of natural rivers is influenced by climatic, hydrological and morphological factors. Regular ice phenomena observation mostly dates back to the 19th century. During this long-term observation period, the human interventions affecting the hydrological and morphological factors have become more and more intensive (Beltaos and Prowse, 2009). The anthropogenic effects, such as river regulation, hydropower use or water pollution causes different changes in river ice regime (Ashton, 1986). To decrease the occurrence of floods and control the water discharge, nowadays most of the rivers are regulated. River regulation changes the morphological parameters of the river bed: the aim is to create solid and equable bed size and stream gradient to prevent river ice congestion. For the satisfaction of increasing water demands hydropower is also used. River damming results a condition like a lake upstream to the barrage; the flow velocity and the turbulence are low, so this might be favourable for river ice appearance and freeze-up (Starosolsky, 1990). Water pollution affects ice regime in two ways; certain water contaminants change the physical characteristics of the water, e.g. lessens the freezing point of the water. Moreover the thermal stress effect of industrial cooling water and communal wastewater is also important; in winter these water sources are usually warmer, than the water body of the river. These interventions result different changes in the characteristic features of river ice regime. Selected

  4. Statistics of exchange rate regimes in Nigeria | Iwueze | Global ...

    African Journals Online (AJOL)

    The three distinct exchange rate regimes of Nigeria were subjected to Autoregressive Integrated Moving Average (ARIMA) modeling in order to compare them with respect to model structure. It was found that the three regimes admit different models. Regime one admits Moving average model of order 2, Regime two admits ...

  5. An emissions trading regime for Canada

    International Nuclear Information System (INIS)

    Smith, S.L.

    2001-01-01

    In 1998, over twelve papers were published on emissions trading regimes in Canada by the National Round Table on the Environment and the Economy (NRTEE), a federal government agency whose members represent stakeholders as varied as business, environmental groups, academics, aboriginal groups and others. One of the recommendations that emerged was for the computer modelling of the possibilities that had been identified for a domestic trading regime in Canada for greenhouse gases. It is unclear whether the modelling was ever performed as the file was taken over by the Finance Department under the umbrella of a special emission trading table that examined Canada's commitment under the Kyoto Protocol. The author examined questions pertaining to whether a domestic trading regime is essential, and what its characteristics should be in case it was deemed essential or advisable to have one. The upstream versus downstream application was looked at, as well as grand-fathering versus auction. Provincial issues were then addressed, followed by meshing with a credit system. International systems were reviewed. Early action was discussed, whereby an emitter seeks credit for action taken toward reductions since the original reference year of 1990. The case of emitters having bought or sold permits since the original reference years will also want those trades recognized under a trading regime. The author indicated that it seems probable that an emission trading system will eventually be implemented and that a debate on the issue should be initiated early

  6. Comprehensive review of the maritime safety regimes.

    NARCIS (Netherlands)

    S. Knapp (Sabine); Ph.H.B.F. Franses (Philip Hans)

    2007-01-01

    textabstractThis report presents a comprehensive review of the maritime safety regimes and provides recommendations on how to improve the system. The results show a complex legal framework which generates a high amount of inspections and overlapping of inspection areas where no cross-recognition is

  7. Radiative effects of global MODIS cloud regimes

    Science.gov (United States)

    Oreopoulos, Lazaros; Cho, Nayeong; Lee, Dongmin; Kato, Seiji

    2018-01-01

    We update previously published MODIS global cloud regimes (CRs) using the latest MODIS cloud retrievals in the Collection 6 dataset. We implement a slightly different derivation method, investigate the composition of the regimes, and then proceed to examine several aspects of CR radiative appearance with the aid of various radiative flux datasets. Our results clearly show the CRs are radiatively distinct in terms of shortwave, longwave and their combined (total) cloud radiative effect. We show that we can clearly distinguish regimes based on whether they radiatively cool or warm the atmosphere, and thanks to radiative heating profiles to discern the vertical distribution of cooling and warming. Terra and Aqua comparisons provide information about the degree to which morning and afternoon occurrences of regimes affect the symmetry of CR radiative contribution. We examine how the radiative discrepancies among multiple irradiance datasets suffering from imperfect spatiotemporal matching depend on CR, and whether they are therefore related to the complexity of cloud structure, its interpretation by different observational systems, and its subsequent representation in radiative transfer calculations. PMID:29619289

  8. Stochastic dynamical models for ecological regime shifts

    DEFF Research Database (Denmark)

    Møller, Jan Kloppenborg; Carstensen, Jacob; Madsen, Henrik

    phytoplankton and benthic vegetation with feedback mechanisms is formulated, and it is demonstrated that bistability can occur for specific parameter settings. When stochastic input and stochastic propagation of the states are applied on the system regime shifts occur more frequently, and the threshold...

  9. European welfare regimes: Political orientations versus poverty

    Directory of Open Access Journals (Sweden)

    Josifidis Kosta

    2011-01-01

    Full Text Available This inquiry analyzes how political orientations shape welfare states and labour market institutions when seeking to reduce poverty. In order to identify effects of these two key variables, we conduct a panel regression analysis that includes two poverty measures: poverty rates before and after social spending. This inquiry considers 14 EU countries, and in the period from 1995 to 2008, which are grouped according to welfare state regimes. We consider Social Democratic, Corporatist, Mediterranean and Liberal welfare state regimes. Panel regression results indicate that political orientation engenders no significant statistically measurable effects on poverty rates before social spending. Effects register, however, as significant when considering poverty rates after social spending. With respect to the first set of results, we advance two key explanations. First, we note a longer period of time is necessary in order to observe actual effects of political orientation on market generated poverty. Second, political parties with their respective programs do not register as influential enough to solve social problems related to income distribution when taken alone. Influences register as indirect and are expressed through changes in employment rates and social spending. The second set of results support the hypothesis that a selected political regime does indeed contribute to poverty reduction. In sum, political orientation and political regime does indeed affect poverty through welfare state institutions, as well as through labour market institutions.

  10. STATISTICS OF EXCHANGE RATE REGIMES IN NIGERIA

    African Journals Online (AJOL)

    Admin

    currency. But since transactions are made in national (domestic) currencies, the former is generally applied for exchange (Mordi, 2006). The main objectives of ... different regimes. In this paper, attempt is made to use Autoregressive Integrated Moving Average. (ARIMA) model to study exchange rate data according to ...

  11. Transitions between risk management regimes in cities

    Directory of Open Access Journals (Sweden)

    William Solecki

    2017-06-01

    Full Text Available Ongoing climate change is encouraging cities to reevaluate their risk management strategies. Urban communities increasingly are being forced to respond to climate shifts with actions that promote resistance, resilience, or even larger scale transformations. Our objective is to present a conceptual framework that facilitates examination of how the transition from one type of risk management strategy or regime to another takes place. The research framework is built around a set of assumptions regarding the process of transition between risk management regimes. The framework includes five basic conceptual elements: (1 risk management regimes, (2 development pathways, (3 activity spheres, (4 activity spaces, and (5 root, contextual, and proximate drivers. The interaction among these elements and the potential for transition between four different possible regime states including resistance, resilience, transformation, and collapse are presented. The framework facilitates and guides analysis on whether and how transition is emergent, constrained, or accelerated in specific contexts. A case study of post-Hurricane Sandy New York is used to illustrate the framework and its overall effectiveness.

  12. Estimation in autoregressive models with Markov regime

    OpenAIRE

    Ríos, Ricardo; Rodríguez, Luis

    2005-01-01

    In this paper we derive the consistency of the penalized likelihood method for the number state of the hidden Markov chain in autoregressive models with Markov regimen. Using a SAEM type algorithm to estimate the models parameters. We test the null hypothesis of hidden Markov Model against an autoregressive process with Markov regime.

  13. EARLY INTERVENTION REGIME UNDER THE BANK ...

    African Journals Online (AJOL)

    OLAWUYI

    2000-03-01

    Mar 1, 2000 ... consumption and investment plans; allocating the savings of households and businesses to ... World Bank Principles and Guidelines for Effective Insolvency and Creditor Rights Systems, IMF's ... February 2009 addressed the immediate need for a special bank resolution regime following the global.

  14. A Comparative Typology of Pension Regimes

    NARCIS (Netherlands)

    Arjan Soede; Cok Vrooman

    2008-01-01

    This report presents an empirical typology of pension regimes in the European Union, the US, Canada, Australia and Norway. The categorisation is based on 34 quantitative and qualitative characteristics of the mandatory parts of the pension systems in these countries. The empirical analysis shows

  15. Yukon's common oil and gas regime

    International Nuclear Information System (INIS)

    Love, B.

    1998-01-01

    The Yukon's common oil and gas regime was developed in partnership with First Nations and it sets out the rules that will apply throughout the Yukon and on Yukon and First Nation lands. While separate and distinct, it conforms with and is compatible with other government systems and regimes. The major elements of the common regime include the Oil and Gas Act, regulations, policies, processes and agreements. The specific opportunities that are available in each phase of oil and gas development in the Yukon are described, with a map showing all basins, reserves and sites of current oil and gas activity. The Yukon has eight potential oil and gas basins: North Coast, Old Crow, Kandik, Eagle Plain, Peel Plateau, Bonnet Plume, Whitehorse Trough, and Liard Plateau. Only three of the eight, the Liard Plateau, Whitehorse Trough and Eagle Plain, have been explored. No wells have been drilled in several of Yukon's basins. Factors influencing economic opportunities in the Territory are also described, including: (1) international events and energy markets, (2) North American gas markets, (3) environmental factors, (4) competitiveness of the Yukon regime, and (5) the commitment of industry resources. 4 figs

  16. The Forex Regime and EMU Expansion

    NARCIS (Netherlands)

    P.W. van Foreest; C.G. de Vries (Casper)

    2002-01-01

    textabstractThis paper provides empirical evidence that, irrespective of the foreign exchange rate regime, countries with high monetary volatility have lower relative output growth rates. It is argued that due to the forward looking nature of the foreign exchange market, exchange rate stability

  17. Early detection of ecosystem regime shifts

    DEFF Research Database (Denmark)

    Lindegren, Martin; Dakos, Vasilis; Groeger, Joachim P.

    2012-01-01

    Critical transitions between alternative stable states have been shown to occur across an array of complex systems. While our ability to identify abrupt regime shifts in natural ecosystems has improved, detection of potential early-warning signals previous to such shifts is still very limited. Us...

  18. [The "specific" liability regime for blood products].

    Science.gov (United States)

    Byk, Christian

    2017-10-13

    Based on the system of liability for defective products as organized by the European Directive of 25 July 1985, responsibility for blood products does not therefore constitute a genuine specific regime. However, European law leaves States a margin of discretion in the implementation of the Directive with regard to health products. This is the case in particular with the exemption for development risk.

  19. STATISTICS OF EXCHANGE RATE REGIMES IN NIGERIA

    African Journals Online (AJOL)

    DJFLEX

    2009-02-11

    Feb 11, 2009 ... KEY WORDS: Exchange Rate Regime; ARIMA Model, Stationarity, Random Walk Model. INTRODUCTION. Exchange rate has been defined as the price of one currency in terms of another. It can be expressed in one of two ways: as units of domestic currency per unit of foreign currency; or units of foreign ...

  20. Searching for an Appropriate Exchange Rate Regime

    Directory of Open Access Journals (Sweden)

    Yunjong Wang

    2001-06-01

    Full Text Available This paper attempts to survey current debates on the choice of exchange rate regime in emerging market economies. The issue of choosing an appropriate exchange rate regime is being actively discussed since the recent Asian crisis. As a lesson from the recent crises, one widely shared conclusion is that soft peg exchange rate regimes are extremely vulnerable in a world of volatile capital movements. Consequently, new orthodoxy based on the impossible trinity hypothesis favours two corner solutions ― greater flexibility or credible institutional assurance, like a currency board system or dollarization. Nevertheless, questions whether such corner solutions are adequate for developing countries are rising of late. "Fear of floating" is still conspicuous in many developing countries having adopted nominally a free-floating exchange rate regime. Developing countries are sensitive to exchange rate fluctuations because the cost of exchange rate volatility is greater than the benefit when compared to developed countries. Monitoring bands is a compromise solution, but it still needs further enhancement of estimation techniques for fundamental equilibrium exchange rates in order to make those estimation results more workable in practice. Other alternatives include the creation of soft peg of the G-3 currencies. Despite counterarguments, the stability of G-3 currencies could prove to be beneficial to emerging market economies.

  1. Regime Shifts and Resilience in Fisheries Management

    NARCIS (Netherlands)

    Li, Chuan Zhong; Villasante, Sebastian; Zhu, Xueqin

    2016-01-01

    We investigate the role of potential regime shifts in Argentinean hake fishery and the inter-linkage between ecological and economic resilience. We develop a theoretical model incorporated with the hazard function for resource management under alternative conditions, and derive the corrective

  2. Negotiating a regime to control global warming

    International Nuclear Information System (INIS)

    Sebenius, J.K.

    1991-01-01

    For purposes of analysis, this paper has uncritically maintained that the prospect of a serious climate problem exists and has only lightly examined the broader advantages and drawbacks of various proposed policy and institutional responses. Crucial as they are to a full treatment of the issues, these underlying substantive and policy questions enter the analysis primarily insofar as they affect the likely outcomes of pending and potential negotiations. To an advocate of a new greenhouse control regime, the fundamental negotiating task is to craft and sustain a meaningful winning coalition of countries backing such a regime. Two centrally necessary conditions for the fundamental task are: (1) that each member of the coalition see enough gain in the regime relative to the alternatives to adhere and (2) the potential and actual blocking coalitions of interests opposed to the regime be prevented from forming and from being acceptably accommodated or otherwise neutralized. The analysis of this paper is organized around key questions whose answers will influence whether and how these two necessary conditions might (or might not) be met

  3. Welfare State Regimes and Caseworkers’ Problem Explanation

    DEFF Research Database (Denmark)

    Møller, Marie Østergaard; Stensöta, Helena Helena Olofsdotter

    2018-01-01

    welfare state regime type. Based on in-depth study of caseworker reasoning in Sweden and Denmark, we find a “structural problem explanation” that sees reasons for clients seeking support as rooted in the structures of society— not in the individual client. We find and present two narratives hitherto...

  4. EUROPEAN INFLUENCE ON ETHIOPIAN ANTITRUST REGIME:

    African Journals Online (AJOL)

    eliasn

    Introduction. Despite a noticeable European influence on the Ethiopian competition legal regime, some aspects of Ethiopia's 2003 Trade Practice Proclamation are still inadequate to appropriately deal with certain competition problems. The limitations of the rules need to be put right since achievement of the very goals of ...

  5. Software for Automated Generation of Reduced Thermal Models for Spacecraft Thermal Control, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermal analysis is increasingly used in the engineering of spacecrafts at every stage, including design, test, and ground-operation simulation. Currently used...

  6. Thermal Stress

    Science.gov (United States)

    2011-01-01

    and Science in Sports and Exercise 37: 1328--1334. Coris EE, Ramirez AM, and Van Durme DJ (2004) Heat illness in athletes : The dangerous combination...of heat, humidity and exercise. Sports Medicine 34: 9--16. Gordon CJ and Leon LR (2005) Thermal stress and the physiological response to environmental...code) 2011 Book Chapter-Enc. of Environmental Health Thermal Stress L.R. Leon, C.J. Gordon Thermal and Mountain Medicine Division U.S. Research

  7. Hot Ground Vibration Tests

    Data.gov (United States)

    National Aeronautics and Space Administration — Ground vibration tests or modal surveys are routinely conducted to support flutter analysis for subsonic and supersonic vehicles. However, vibration testing...

  8. The global safety regime - Setting the stage

    International Nuclear Information System (INIS)

    Meserve, R.A.

    2005-01-01

    The existing global safety regime has arisen from the exercise of sovereign authority, with an overlay of voluntary international cooperation from a network of international and regional organizations and intergovernmental agreements. This system has, in the main, served us well. For several reasons, the time is ripe to consider the desired shape of a future global safety regime and to take steps to achieve it. First, every nation's reliance on nuclear power is hostage to some extent to safety performance elsewhere in the world because of the effects on public attitudes and hence there is an interest in ensuring achievement of common standards. Second, the world is increasingly interdependent and the vendors of nuclear power plants seek to market their products throughout the globe. Efficiency would arise from the avoidance of needless differences in approach that require custom modifications from country to country. Finally, we have much to learn from each other and a common effort would strengthen us all. Such an effort might also serve to enhance public confidence. Some possible characteristics of such a regime can be identified. The regime should reflect a global consensus on the level of safety that should be achieved. There should be sufficient standardization of approach so that expertise and equipment can be used everywhere without significant modification. There should be efforts to ensure a fundamental commitment to safety and the encouragement of a safety culture. And there should be efforts to adopt more widely the best regulatory practices, recognizing that some modifications in approach may be necessary to reflect each nation's legal and social culture. At the same type, the regime should have the characteristics of flexibility, transparency, stability, practicality, and encouragement of competence. (author)

  9. Dune growth under multidirectional wind regimes

    Science.gov (United States)

    Gadal, C.; Rozier, O.; Claudin, P.; Courrech Du Pont, S.; Narteau, C.

    2017-12-01

    Under unidirectional wind regimes, flat sand beds become unstable to produce periodic linear dunes, commonly called transverse dunes because their main ridges are oriented perpendicular to the air flow. In areas of low sediment availability, the same interactions between flow, transport and topography produce barchan dunes, isolated sand-pile migrating over long distances with a characteristic crescentic shape. For the last fifteen years, barchan dunes and the instability at the origin of transverse dunes have been the subject of numerous studies that have identified a set of characteristic length and time scales with respect to the physical properties of both grains and fluid. This is not the case for dunes developing under multidirectional wind regimes. Under these conditions, dune orientation is measured with respect to the direction of the resultant sand flux. Depending on the wind regime, dunes do not always line up perpendicularly to the resultant sand flux, but can also be at an oblique angle or even parallel to it. These oblique and longitudinal dunes are ubiquitous in all deserts on Earth and planetary bodies because of the seasonal variability of wind orientation. They are however poorly constrained by observations and there is still no complete theoretical framework providing a description of their orientation and initial wavelength. Here, we extend the linear stability analysis of a flat sand of bed done in two dimensions for a unidirectional flow to three dimensions and multidirectional flow regimes. We are able to recover transitions from transverse to oblique or longitudinal dune patterns according to changes in wind regimes. We besides give a prediction for the initial dune wavelength. Our results compare well to previous theory of dune orientation and to field, experimental and numerical data.

  10. Thermal transport in boron nitride nanotorus—towards a nanoscopic thermal shield

    International Nuclear Information System (INIS)

    Loh, G. C.; Baillargeat, D.

    2013-01-01

    Nanotori, or nanorings, are topological variants of nanotubes and are conceived to have different properties from their tubular form. In this study, the toroidal arrangement of boron nitride is introduced. Using classical molecular dynamics simulations, the thermal behaviour (thermal conductivity and thermal stability) of the boron nitride nanotorus and its relationship with the structural characteristics are investigated. Its circumferential thermal rectification strength displays a linear dependence on the bending coefficient of the nanostructure. Surface kinks are relatively inconsequential on its circumferential mode of conduction, as compared to its axial sense. The circumferential conductivity in the diffusive regime is calculated to be approximately 10 W/m K, while the axial conductivity is more than tenfold of this value. All nanotori with different toroidal characters show excellent thermal stability at extremely high temperatures approaching 3400 K. With consideration to its favourable properties, a thermal shield made up of a parallel row of nanotori is proposed as a nanoscale thermal insulation device

  11. Quantifying the Influence of Near-Surface Water-Energy Budgets on Soil Thermal Properties Using a Network of Coupled Meteorological and Vadose Zone Instrument Arrays in Indiana, USA

    Science.gov (United States)

    Naylor, S.; Gustin, A. R.; Ellett, K. M.

    2012-12-01

    known standards and comparing measurements from transient line heat source devices. Transform equations have been developed to correct in-situ measurements of thermal conductivity and comparing these results with soil moisture data indicates that thermal conductivity can increase by as much as 25 percent during wetting front propagation. Thermal dryout curves have also been modeled based on laboratory conductivity data collected from core samples to verify field measurements, and alternatively, temperature profile data are used to calibrate near-surface temperature gradient models. We compare data collected across various spatial scales to assess the potential for upscaling near-surface thermal regimes based on available soils data. A long-term goal of the monitoring effort is to establish continuous data sets that determine the effect of climate variability on soil thermal properties such that expected ranges in thermal conductivity can be used to determine optimal ground-coupling loop lengths for GSHP systems.

  12. Rainbow trout versus brook trout biomass and production under varied climate regimes in small southern Appalachian streams

    Science.gov (United States)

    Bonnie. J.E. Myers; C. Andrew Dolloff; Andrew L. Rypel

    2014-01-01

    Many Appalachian streams historically dominated by Brook Trout Salvelinus fontinalis have experienced shifts towards fish communities dominated by Rainbow Trout Onchorhynchus mykiss. We used empirical estimates of biomass and secondary production of trout conspecifics to evaluate species success under varied thermal regimes. Trout...

  13. Rearrangements in ground and excited states

    CERN Document Server

    de Mayo, Paul

    1980-01-01

    Rearrangements in Ground and Excited States, Volume 2 covers essays on the theoretical approach of rearrangements; the rearrangements involving boron; and the molecular rearrangements of organosilicon compounds. The book also includes essays on the polytopal rearrangement at phosphorus; the rearrangement in coordination complexes; and the reversible thermal intramolecular rearrangements of metal carbonyls. Chemists and people involved in the study of rearrangements will find the book invaluable.

  14. Natural selection on thermal performance in a novel thermal environment.

    Science.gov (United States)

    Logan, Michael L; Cox, Robert M; Calsbeek, Ryan

    2014-09-30

    Tropical ectotherms are thought to be especially vulnerable to climate change because they are adapted to relatively stable temperature regimes, such that even small increases in environmental temperature may lead to large decreases in physiological performance. One way in which tropical organisms may mitigate the detrimental effects of warming is through evolutionary change in thermal physiology. The speed and magnitude of this response depend, in part, on the strength of climate-driven selection. However, many ectotherms use behavioral adjustments to maintain preferred body temperatures in the face of environmental variation. These behaviors may shelter individuals from natural selection, preventing evolutionary adaptation to changing conditions. Here, we mimic the effects of climate change by experimentally transplanting a population of Anolis sagrei lizards to a novel thermal environment. Transplanted lizards experienced warmer and more thermally variable conditions, which resulted in strong directional selection on thermal performance traits. These same traits were not under selection in a reference population studied in a less thermally stressful environment. Our results indicate that climate change can exert strong natural selection on tropical ectotherms, despite their ability to thermoregulate behaviorally. To the extent that thermal performance traits are heritable, populations may be capable of rapid adaptation to anthropogenic warming.

  15. Constraining Non-thermal and Thermal properties of Dark Matter

    Directory of Open Access Journals (Sweden)

    Bhupal eDev

    2014-05-01

    Full Text Available We describe the evolution of Dark Matter (DM abundance from the very onset of its creation from inflaton decay under the assumption of an instantaneous reheating. Based on the initial conditions such as the inflaton mass and its decay branching ratio to the DM species, the reheating temperature, and the mass and interaction rate of the DM with the thermal bath, the DM particles can either thermalize (fully/partially with the primordial bath or remain non-thermal throughout their evolution history. In the thermal case, the final abundance is set by the standard freeze-out mechanism for large annihilation rates, irrespective of the initial conditions. For smaller annihilation rates, it can be set by the freeze-in mechanism which also does not depend on the initial abundance, provided it is small to begin with. For even smaller interaction rates, the DM decouples while being non-thermal, and the relic abundance will be essentially set by the initial conditions. We put model-independent constraints on the DM mass and annihilation rate from over-abundance by exactly solving the relevant Boltzmann equations, and identify the thermal freeze-out, freeze-in and non-thermal regions of the allowed parameter space. We highlight a generic fact that inflaton decay to DM inevitably leads to an overclosure of the Universe for a large range of DM parameter space, and thus poses a stringent constraint that must be taken into account while constructing models of DM. For the thermal DM region, we also show the complementary constraints from indirect DM search experiments, Big Bang Nucleosynthesis, Cosmic Microwave Background, Planck measurements, and theoretical limits due to the unitarity of S-matrix. For the non-thermal DM scenario, we show the allowed parameter space in terms of the inflaton and DM masses for a given reheating temperature, and compute the comoving free-streaming length to identify the hot, warm and cold DM regimes.

  16. Thermal conductivity and thermal diffusivity

    International Nuclear Information System (INIS)

    Hust, J.G.

    1983-01-01

    This chapter examines the heat transfer properties of solids, with emphasis on the behavior of pure metals and alloys. Topics considered include electronic conduction, magnetic field effects, lattice conduction, measuring methods, specimen size, uncertainty, thermal anchoring, radial heat loss, thermal conductivity apparatus, thermal diffusivity apparatus, empirical correlations, the Wiedemann-Franz-Lorenz law, Matthiessen's rule, low-temperature correlation, predictive techniques, crystalline dielectrics, and disordered dielectrics. The materials examined include copper, aluminium, binary alloys, structural alloys, and structural composites

  17. Underground Coal Thermal Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P. [Univ. of Utah, Salt Lake City, UT (United States); Deo, M. [Univ. of Utah, Salt Lake City, UT (United States); Eddings, E. [Univ. of Utah, Salt Lake City, UT (United States); Sarofim, A. [Univ. of Utah, Salt Lake City, UT (United States); Gueishen, K. [Univ. of Utah, Salt Lake City, UT (United States); Hradisky, M. [Univ. of Utah, Salt Lake City, UT (United States); Kelly, K. [Univ. of Utah, Salt Lake City, UT (United States); Mandalaparty, P. [Univ. of Utah, Salt Lake City, UT (United States); Zhang, H. [Univ. of Utah, Salt Lake City, UT (United States)

    2012-01-11

    The long-term objective of this work is to develop a transformational energy production technology by insitu thermal treatment of a coal seam for the production of substitute natural gas (SNG) while leaving much of the coal's carbon in the ground. This process converts coal to a high-efficiency, low-GHG emitting gas fuel. It holds the potential of providing environmentally acceptable access to previously unusable coal resources. This topical report discusses the development of experimental capabilities, the collection of available data, and the development of simulation tools to obtain process thermo-chemical and geo-thermal parameters in preparation for the eventual demonstration in a coal seam. It also includes experimental and modeling studies of CO2 sequestration.

  18. Geographic analysis of thermal equilibria: A bioenergetic model for predicting thermal response of aquatic insect communities

    International Nuclear Information System (INIS)

    Sweeney, B.W.; Newbold, J.D.; Vannote, R.L.

    1991-12-01

    The thermal regime immediately downstream from bottom release reservoirs is often characterized by reduced diel and seasonal (winter warm/summer cool) conditions. These unusual thermal patterns have often been implicated as a primary factor underlying observed downstream changes in the species composition of aquatic macroinvertebrate communities. The potential mechanisms for selective elimination of benthic species by unusual thermal regimes has been reviewed. Although the effects of temperature on the rate and magnitude of larval growth and development has been included in the list of potential mechanisms, only recently have field studies below dams focused on this interrelationship. This study investigates the overall community structure as well as the seasonal pattern of larval growth and development for several univoltine species of insects in the Delaware River below or near the hypolimnetic discharge of the Cannonsville and Pepeacton dams. These dams, which are located on the West and East branches of the Delaware River, respectively, produce a thermal gradient extending about 70 km downstream

  19. Critical thermal limits affected differently by developmental and adult thermal fluctuations

    DEFF Research Database (Denmark)

    Salachan, Paul Vinu; Sørensen, Jesper Givskov

    2017-01-01

    Means and variances of the environmental thermal regime play an important role in determining the fitness of terrestrial ectotherms. Adaptive phenotypic responses induced by heterogeneous temperatures have been shown to be mediated by molecular pathways independent of the classic heat shock...... responses, however, an in-depth understanding of plasticity induced by fluctuating temperatures is still lacking. We investigated high and low temperature acclimation induced by fluctuating thermal regimes at two different mean temperatures, at two different amplitudes of fluctuation and across...... the developmental and adult life stages. For developmental acclimation, we found mildly detrimental effects of high amplitude fluctuations for critical thermal minima, while the critical thermal maxima showed a beneficial response to higher amplitude fluctuations. For adult acclimation involving shifts between...

  20. Efektivitas Instagram Common Grounds

    OpenAIRE

    Wifalin, Michelle

    2016-01-01

    Efektivitas Instagram Common Grounds merupakan rumusan masalah yang diambil dalam penelitian ini. Efektivitas Instagram diukur menggunakan Customer Response Index (CRI), dimana responden diukur dalam berbagai tingkatan, mulai dari awareness, comprehend, interest, intentions dan action. Tingkatan respons inilah yang digunakan untuk mengukur efektivitas Instagram Common Grounds. Teori-teori yang digunakan untuk mendukung penelitian ini yaitu teori marketing Public Relations, teori iklan, efekti...

  1. Pesticides in Ground Water

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup

    1996-01-01

    Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588.......Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588....

  2. Thermal insulation

    International Nuclear Information System (INIS)

    Pinsky, G.P.

    1977-01-01

    Thermal insulation for vessels and piping within the reactor containment area of nuclear power plants is disclosed. The thermal insulation of this invention can be readily removed and replaced from the vessels and piping for inservice inspection, can withstand repeated wettings and dryings, and can resist high temperatures for long periods of time. 4 claims, 3 figures

  3. Communication, concepts and grounding.

    Science.gov (United States)

    van der Velde, Frank

    2015-02-01

    This article discusses the relation between communication and conceptual grounding. In the brain, neurons, circuits and brain areas are involved in the representation of a concept, grounding it in perception and action. In terms of grounding we can distinguish between communication within the brain and communication between humans or between humans and machines. In the first form of communication, a concept is activated by sensory input. Due to grounding, the information provided by this communication is not just determined by the sensory input but also by the outgoing connection structure of the conceptual representation, which is based on previous experiences and actions. The second form of communication, that between humans or between humans and machines, is influenced by the first form. In particular, a more successful interpersonal communication might require forms of situated cognition and interaction in which the entire representations of grounded concepts are involved. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage

    Science.gov (United States)

    2017-03-21

    EW-201135) Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage March 2017 This document has been cleared for...09/2011-03/2017 4. TITLE AND SUBTITLE Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage 5a...v ACRONYMS AND ABBREVIATIONS AGWT American Ground Water Trust AHU Air Handling Unit ATES Aquifer Thermal Energy Storage BTES Borehole

  5. Choice of exchange rate regimes for African countries: Fixed or Flexible Exchange rate regimes?

    OpenAIRE

    Simwaka, Kisu

    2010-01-01

    The choice of an appropriate exchange rate regime has been a subject of ongoing debate in international economics. The majority of African countries are small open economies and thus where the choice of the exchange rate regime is an important policy issue. Aside from factors such as interest rates and inflation, the exchange rate is one of the most important determinants of a country’s relative level of economic health. For this reason, exchange rates are among the most watched analyzed and ...

  6. Thermal escape from extrasolar giant planets.

    Science.gov (United States)

    Koskinen, Tommi T; Lavvas, Panayotis; Harris, Matthew J; Yelle, Roger V

    2014-04-28

    The detection of hot atomic hydrogen and heavy atoms and ions at high altitudes around close-in extrasolar giant planets (EGPs) such as HD209458b implies that these planets have hot and rapidly escaping atmospheres that extend to several planetary radii. These characteristics, however, cannot be generalized to all close-in EGPs. The thermal escape mechanism and mass loss rate from EGPs depend on a complex interplay between photochemistry and radiative transfer driven by the stellar UV radiation. In this study, we explore how these processes change under different levels of irradiation on giant planets with different characteristics. We confirm that there are two distinct regimes of thermal escape from EGPs, and that the transition between these regimes is relatively sharp. Our results have implications for thermal mass loss rates from different EGPs that we discuss in the context of currently known planets and the detectability of their upper atmospheres.

  7. The optomechanical instability in the quantum regime

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Max; Kubala, Bjoern; Marquardt, Florian [Department fuer Physik, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians-Universitaet Muenchen, Theresienstr 37, D-80333 Muenchen (Germany)], E-mail: max.ludwig@physik.lmu.de

    2008-09-15

    We consider a generic optomechanical system, consisting of a driven optical cavity and a movable mirror attached to a cantilever. Systems of this kind (and analogues) have been realized in many recent experiments. It is well known that these systems can exhibit an instability towards a regime where the cantilever settles into self-sustained oscillations. In this paper, we briefly review the classical theory of the optomechanical instability, and then discuss the features arising in the quantum regime. We solve numerically a full quantum master equation for the coupled system, and use it to analyze the photon number, the cantilever's mechanical energy, the phonon probability distribution and the mechanical Wigner density, as a function of experimentally accessible control parameters. When a suitable dimensionless 'quantum parameter' is sent to zero, the results of the quantum mechanical model converge towards the classical predictions. We discuss this quantum-to-classical transition in some detail.

  8. Steady and transient regimes in hydropower plants

    Science.gov (United States)

    Gajic, A.

    2013-12-01

    Hydropower plant that has been in operation for about 30 years has to be reconstructed. They have already installed 12 Kaplan turbines, the largest in the world at that time. The existing CAM relationship was determined based on hydraulic model tests and checked by efficiency on-site tests. It was also tested based on turbine bearing vibrations. In order to discover vibrations and long cracks on stay vanes detailed on-site measurements were performed. Influence of the modification of the trailing edges on the dynamic stresses of the stay vanes is also shown. In order to improve power output transient regimes were analyzed, both experimentally and numerically. Reversible hydropower plant, a pioneer in Europe since it was the first Pump storage power plant constructed with the highest head pump-turbines in the world. Analyses of transient regimes discover some problems with S-shaped characteristics coupled with non-symmetrical penstock.

  9. Coulomb drag in the mesoscopic regime

    DEFF Research Database (Denmark)

    Mortensen, N. Asger; Flensberg, Karsten; Jauho, Antti-Pekka

    2002-01-01

    We present a theory for Coulomb drug between two mesoscopic systems which expresses the drag in terms of scattering matrices and wave functions. The formalism can be applied to both ballistic and disordered systems and the consequences can be studied either by numerical simulations or analytic...... means such as perturbation theory or random matrix theory. The physics of Coulomb drag in the mesoscopic regime is very different from Coulomb drag between extended electron systems. In the mesoscopic regime we in general find fluctuations of the drag comparable to the mean value. Examples are vanishing...... average drag for chaotic 2D-systems and dominating fluctuations of drag between quasi-ballistic wires with almost ideal transmission....

  10. Coulomb drag in the mesoscopic regime

    DEFF Research Database (Denmark)

    Mortensen, N.A.; Flensberg, Karsten; Jauho, Antti-Pekka

    2002-01-01

    We present a theory for Coulomb drag between two mesoscopic systems which expresses the drag in terms of scattering matrices and wave functions. The formalism can be applied to both ballistic and disordered systems and the consequences can be studied either by numerical simulations or analytic...... means such as perturbation theory or random matrix theory. The physics of Coulomb drag in the mesoscopic regime is very different from Coulomb drag between extended electron systems. In the mesoscopic regime we in general find fluctuations of the drag comparable to the mean value. Examples are vanishing...... average drag for chaotic 2D-systems and dominating fluctuations of drag between quasi-ballistic wires with almost ideal transmission....

  11. Regimes de espaço

    Directory of Open Access Journals (Sweden)

    Eric Landowski

    2015-06-01

    Full Text Available Space Regimes - Based on a general model of interaction, the present analysis attempts to account for the diversity of the ways space may be apprehended in lived experience. It leads to the definition of four configurations that correspond to as many regimes of relation with the environing world. The conventional space of the circulation of values takes the archetypical shape of the net (incarnated today by Internet. The operational space is that of our dealing with objects within a material environment seen as a tissue of stable and intelligible relations. The experienced space of bodies’ movement, to which one may give as an emblem the spiral, expresses the dynamics of sensitive relationships between the self and the other. The existential space is that of our presence in a universe without boundaries, which no one can properly represent oneself but that nonetheless haunts art and thought: its figure is the abyss.

  12. Mesoscopic effects in the quantum Hall regime

    Indian Academy of Sciences (India)

    creases, while at the critical point the Thouless number goes to a universal value. In the scaling regime, the dimensionless quantity depends on system size only through the ratio. L/ξ(E): gL(E) = ˜g(L/ξ) =g(L1 ν. E Ec ),. (9) where the localization length ξ diverges at the critical energy Ec, in a power law fashion ξ(E) E Ec ν.

  13. Dynamic Regime of Ignition of Solid Propellant

    Directory of Open Access Journals (Sweden)

    Zolotorev Nikolay

    2016-01-01

    Full Text Available This article presents a dynamic regime of exposure of the radiant flux on the sample of gun-cotton. Obtained time the ignition of gun-cotton in the heating conditions of increasing heat flux in the range from 0.2 W/cm2 to 22 W/cm2. A comparison of the delay times of the ignition when heated variable and constant heat flux.

  14. Deuteron structure in the deep inelastic regime

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Canal, C.A.; Tarutina, T. [Universidad Nacional de La Plata, IFLP/CONICET y Departamento de Fisica, La Plata (Argentina); Vento, V. [Universidad de Valencia-CSIC, Departamento de Fisica Teorica-IFIC, Burjassot (Valencia) (Spain)

    2017-06-15

    We study nuclear effects in the deuteron in the deep inelastic regime using the newest available data. We put special emphasis on their Q{sup 2} dependence. The study is carried out using a scheme which parameterizes, in a simple manner, these effects by changing the proton and neutron stucture functions in medium. The result of our analysis is compared with other recent proposals. We conclude that precise EMC ratios cannot be obtained without considering the nuclear effects in the deuteron. (orig.)

  15. Supersonic free jet, molecular free regime

    International Nuclear Information System (INIS)

    Sanna, G.; Tomassetti, G.

    1999-01-01

    The structure of the free jet emitted by a converging nozzle as obtained by the method of characteristics by Ashkenas and Sherman is described in details. In particular the dependence of the field variable by the distance from the nozzle is given. The transition from continuum to molecular free regime is then considered and the sudden freeze approximation is introduced. The processing of monoatomic and polyatomic gasses is also considered [it

  16. Tax compliance under tax regime changes

    OpenAIRE

    Heinemann, Friedrich; Kocher, Martin G.

    2010-01-01

    In this paper we focus on the compliance effects of tax regime changes. According to the economic model of tax evasion, a tax reform should affect compliance through its impact on tax rates and incentives. Our findings demonstrate the importance of at least two further effects not covered by the traditional model: First, reform losers tend to evade more taxes after the reform. Second, a reform from a proportionate to a progressive system decreases compliance compared to a switch in the revers...

  17. Localization and the effects of symmetries in the thermalization properties of one-dimensional quantum systems.

    Science.gov (United States)

    Santos, Lea F; Rigol, Marcos

    2010-09-01

    We study how the proximity to an integrable point or to localization as one approaches the atomic limit, as well as the mixing of symmetries in the chaotic domain, may affect the onset of thermalization in finite one-dimensional systems. We consider systems of hard-core bosons at half-filling with nearest-neighbor hopping and interaction, and next-nearest-neighbor interaction. The latter breaks integrability and induces a ground-state superfluid to insulator transition. By full exact diagonalization, we study chaos indicators and few-body observables. We show that when different symmetry sectors are mixed, chaos indicators associated with the eigenvectors, contrary to those related to the eigenvalues, capture the onset of chaos. The results for the complexity of the eigenvectors and for the expectation values of few-body observables confirm the validity of the eigenstate thermalization hypothesis in the chaotic regime, and therefore the occurrence of thermalization. We also study the properties of the off-diagonal matrix elements of few-body observables in relation to the transition from integrability to chaos and from chaos to localization.

  18. ACCESSORIES OF FISCAL OBLIGATION. LEGAL REGIME

    Directory of Open Access Journals (Sweden)

    RADA POSTOLACHE

    2012-05-01

    Full Text Available The interest – which is an institution typical to private law, has been taken over by the fiscal field and adapted to the specific features of fiscal obligation – being defined by its imperative legal regime, which has at the least the following characteristic elements: unitary character, imposed legal percentage, compulsory demand of interest, automatic application. In order to render responsible fiscal debtors, the lawmaker has reintroduced, as an accessory of fiscal obligation, delayed payment penalties, which have a distinct nature and legal regime, but without the principle non bis in idem being transgressed. Our study aims to establish the legal regime ofaccessories typical to fiscal obligation, from the perspective of special normative acts, but also of the common law within the field – Civil Code and Government Ordinance No. 13/2011 – by pointing out at the same time both the particular circumstances and procedural ones regulated by the Fiscal Procedure Code, shedding light upon the controversial legal nature of accessories.

  19. Detecting spatial regimes in ecosystems | Science Inventory ...

    Science.gov (United States)

    Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use change and climate change and their effects on plant and animal communities. We use Fisher information, an information theory based method, on both terrestrial and aquatic animal data (US Breeding Bird Survey and marine zooplankton) to identify ecological boundaries, and compare our results to traditional early warning indicators, conventional ecoregion maps, and multivariate analysis such as nMDS (non-metric Multidimensional Scaling) and cluster analysis. We successfully detect spatial regimes and transitions in both terrestrial and aquatic systems using Fisher information. Furthermore, Fisher information provided explicit spatial information about community change that is absent from other multivariate approaches. Our results suggest that defining spatial regimes based on animal communities may better reflect ecological reality than do traditional ecoregion maps, especially in our current era of rapid and unpredictable ecological change. Use an information theory based method to identify ecological boundaries and compare our results to traditional early warning

  20. Particle optics in the Rayleigh regime.

    Science.gov (United States)

    Moosmüller, Hans; Arnott, W Patrick

    2009-09-01

    Light scattering and absorption by particles suspended in the atmosphere modifies the transfer of solar energy in the atmosphere, thereby influencing global and regional climate change and atmospheric visibility. Of particular interest are the optical properties of particles in the Rayleigh regime, where particles are small compared with the wavelength of the scattered or absorbed light, because these particles experience little gravitational settlement and may have long atmospheric lifetimes. Optical properties of particles in the Rayleigh regime are commonly derived from electromagnetic theory using Maxwell's equations and appropriate boundary conditions. The size dependence of particle scattering and absorption are derived here from the most basic principles for coherent processes such as Rayleigh scattering (i.e., add amplitudes if in phase) and incoherent processes such as absorption (i.e., add cross sections), at the same time yielding understanding of the upper particle size limit for the Rayleigh regime. The wavelength dependence of Rayleigh scattering and absorption are also obtained by adding a basic scale invariance for particle optics. Simple consequences for particle single-scattering albedo ("whiteness") and the optical measurement of particle mass densities are explained. These alternative derivations complement the conventional understanding obtained from electromagnetic theory.

  1. "International regime for advancing lunar development"

    Science.gov (United States)

    Beldavs, VZ

    2017-09-01

    A specific concern regarding the Moon Treaty is the provision for sharing the wealth gained from space with developing countries that have not invested and taken risks in making possible space materials utilization. Article 11, par. 7 states "The main purposes of the international regime to be established shall include: (a) The orderly and safe development of the natural resources of the moon; (b) The rational management of those resources; (c) The expansion of opportunities in the use of those resources; (d) An equitable sharing by all States Parties in the benefits derived from those resources, whereby the interests and needs of the developing countries, as well as the efforts of those countries which have contributed either directly or indirectly to the exploration of the moon, shall be given special consideration." Whether the Moon Treaty in its present form or modified to be acceptable to more parties or the Moon Treaty is ignored, the language of Article 11, paragraph 7 can be used to construct an international regime for lunar development that can meet the requirements of commercial business as well as of states that provide support for lunar development as well as developing countries that may have played a modest role in making lunar development possible. This paper will consider options for constructing an international regime for lunar development.

  2. The contribution of geology and groundwater studies to city-scale ground heat network strategies: A case study from Cardiff, UK

    Science.gov (United States)

    Boon, David; Farr, Gareth; Patton, Ashley; Kendall, Rhian; James, Laura; Abesser, Corinna; Busby, Jonathan; Schofield, David; White, Debbie; Gooddy, Daren; James, David; Williams, Bernie; Tucker, David; Knowles, Steve; Harcombe, Gareth

    2016-04-01

    monitoring have provided an initial indication of ground constraints and opportunities supporting development of aquifer thermal energy systems in Cardiff. Ground models should consider the past and future anthropogenic processes that influence and modify the condition of the ground. These include heat losses from buildings, modification of the groundwater regime by artificial pumping, sewers, and other GSH schemes, and construction hazards such as buried infrastructure, old foundations, land contamination and un-exploded ordnance. This knowledge base forms the foundation for a 'whole life' approach for sustainable thermal use of the subsurface. Benefits of the approach include; timely and easy to understand information for land use and financial resource planning, reduced financial risk for developers and investors, clear evidence to help improve public perception of GSHP technology, and provision of independent environmental data to satisfy the needs of the regulator. References: Patton, A.M., Farr, G.J., Boon, D.P., James, D.R., Williams, B., Newell, A.J. 2015. Shallow Groundwater Temperatures and the Urban Heat Island Effect: the First U.K City-wide Geothermal Map to Support Development of Ground Source Heating Systems Strategy. Geophysical Research Abstracts. EGU 2015 Vienna, Austria. (Poster)

  3. Advanced thermal management technologies for defense electronics

    Science.gov (United States)

    Bloschock, Kristen P.; Bar-Cohen, Avram

    2012-05-01

    Thermal management technology plays a key role in the continuing miniaturization, performance improvements, and higher reliability of electronic systems. For the past decade, and particularly, the past 4 years, the Defense Advanced Research Projects Agency (DARPA) has aggressively pursued the application of micro- and nano-technology to reduce or remove thermal constraints on the performance of defense electronic systems. The DARPA Thermal Management Technologies (TMT) portfolio is comprised of five technical thrust areas: Thermal Ground Plane (TGP), Microtechnologies for Air-Cooled Exchangers (MACE), NanoThermal Interfaces (NTI), Active Cooling Modules (ACM), and Near Junction Thermal Transport (NJTT). An overview of the TMT program will be presented with emphasis on the goals and status of these efforts relative to the current State-of-the-Art. The presentation will close with future challenges and opportunities in the thermal management of defense electronics.

  4. Overview of thermal conductivity models of anisotropic thermal insulation materials

    Science.gov (United States)

    Skurikhin, A. V.; Kostanovsky, A. V.

    2017-11-01

    Currently, the most of existing materials and substances under elaboration are anisotropic. It makes certain difficulties in the study of heat transfer process. Thermal conductivity of the materials can be characterized by tensor of the second order. Also, the parallelism between the temperature gradient vector and the density of heat flow vector is violated in anisotropic thermal insulation materials (TIM). One of the most famous TIM is a family of integrated thermal insulation refractory material («ITIRM»). The main component ensuring its properties is the «inflated» vermiculite. Natural mineral vermiculite is ground into powder state, fired by gas burner for dehydration, and its precipitate is then compressed. The key feature of thus treated batch of vermiculite is a package structure. The properties of the material lead to a slow heating of manufactured products due to low absorption and high radiation reflection. The maximum of reflection function is referred to infrared spectral region. A review of current models of heat propagation in anisotropic thermal insulation materials is carried out, as well as analysis of their thermal and optical properties. A theoretical model, which allows to determine the heat conductivity «ITIRM», can be useful in the study of thermal characteristics such as specific heat capacity, temperature conductivity, and others. Materials as «ITIRM» can be used in the metallurgy industry, thermal energy and nuclear power-engineering.

  5. Molecular thermal transistor: Dimension analysis and mechanism

    Science.gov (United States)

    Behnia, S.; Panahinia, R.

    2018-04-01

    Recently, large challenge has been spent to realize high efficient thermal transistors. Outstanding properties of DNA make it as an excellent nano material in future technologies. In this paper, we introduced a high efficient DNA based thermal transistor. The thermal transistor operates when the system shows an increase in the thermal flux despite of decreasing temperature gradient. This is what called as negative differential thermal resistance (NDTR). Based on multifractal analysis, we could distinguish regions with NDTR state from non-NDTR state. Moreover, Based on dimension spectrum of the system, it is detected that NDTR state is accompanied by ballistic transport regime. The generalized correlation sum (analogous to specific heat) shows that an irregular decrease in the specific heat induces an increase in the mean free path (mfp) of phonons. This leads to the occurrence of NDTR.

  6. Longevity of Emplacement Drift Ground Support Materials

    Energy Technology Data Exchange (ETDEWEB)

    Tang, David H.

    2001-05-30

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for the selection of materials for ground support that will function throughout the preclosure period of a potential repository at Yucca Mountain. REV 01 ICN 01 of this analysis is developed in accordance with AP-3.10Q, Analyses and Models, Revision 2, ICN 4, and prepared in accordance with the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M&O 2001a). The objective of this analysis is to update the previous analysis (CRWMS M&O 2000a) to account for related changes in the Ground Control System Description Document (CRWMS M&O 2000b), the Monitored Geologic Repository Project Description Document, which is included in the Requirements and Criteria for Implementing a Repository Design that can be Operated Over a Range of Thermal Modes (BSC 2001), input information, and in environmental conditions, and to provide updated information on candidate ground support materials. Candidate materials for ground support are carbon steel and cement grout. Steel is mainly used for steel sets, lagging, channel, rock bolts, and wire mesh. Cement grout is only considered in the case of grouted rock bolts. Candidate materials for the emplacement drift invert are carbon steel and granular natural material. Materials are evaluated for the repository emplacement drift environment based on the updated thermal loading condition and waste package design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground support materials for use in emplacement drifts. (2) Review existing documents concerning the behavior of candidate ground support materials during the preclosure period. (3) Evaluate impacts of temperature and radiation effects on mechanical and thermal properties of steel. Assess corrosion potential of steel at emplacement drift environment. (4) Evaluate factors

  7. On slippery ground:

    DEFF Research Database (Denmark)

    Olesen, Birgitte Ravn; Nordentoft, Helle Merete

    2018-01-01

    , as researchers, found ourselves on slippery and emotionally charged ground. Using a critical, reflexive approach informed by poststructuralism, our ambition was to deconstruct gaps between rhetoric and practice and critique normative understandings of the nature of ethically sound coproduction processes...

  8. Heat transfer characteristics of various kinds of ground heat exchangers for ground source heat pump system

    Science.gov (United States)

    Miyara, A.; Kariya, K.; Ali, Md. H.; Selamat, S. B.; Jalaluddin

    2017-01-01

    Three kinds of vertical-type ground heat exchangers, U-tube; double-tube; multi-tube, and two kinds of horizontal-type ground heat exchangers, standing Slinky; reclined Slinky, were experimentally and numerically investigated in order to clarify their heat transfer characteristics. Experiments and simulations were carried out under two operation conditions which are continuous operation mode and discontinuous operation mode and effects of temperature recovery and thermal storage on the heat transfer rate were shown. Differences of the heat transfer rate between standing Slinky and reclined Slinky were also indicated.

  9. Grounding, shielding, and bonding

    Science.gov (United States)

    Catrysse, J.

    1991-06-01

    In the electromagnetic compatibility design (EMC) of systems and circuits, both grounding and shielding are related to the coupling mechanisms of the system with (radiated) electromagnetic fields. Grounding is more related to the source or victim circuit (or system) and determines the characteristic of the coupling mechanism between fields and currents/voltages. Shielding is a way of interacting in the radiation path of an electromagnetic field. The basic principles and practical design rules are discussed.

  10. Refrigeration. Two-Phase Flow. Flow Regimes and Pressure Drop

    DEFF Research Database (Denmark)

    Knudsen, Hans-Jørgen Høgaard

    2002-01-01

    The note gives the basic definitions used in two-phase flow. Flow regimes and flow regimes map are introduced. The different contributions to the pressure drop are stated together with an imperical correlation from the litterature.......The note gives the basic definitions used in two-phase flow. Flow regimes and flow regimes map are introduced. The different contributions to the pressure drop are stated together with an imperical correlation from the litterature....

  11. Terms of trade and exchange rate regimes in developing countries

    OpenAIRE

    Christian Broda

    2002-01-01

    Since Friedman (1953), an advantage often attributed to flexible exchange rate regimes over fixed regimes is their ability to insulate more effectively the economy against real shocks. I use a post-Bretton Woods sample (1973-96) of seventy-five developing countries to assess whether the responses of real GDP, real exchange rates, and prices to terms-of-trade shocks differ systematically across exchange rate regimes. I find that responses are significantly different across regimes in a way tha...

  12. Seasonal Thermal Energy Storage Program

    Science.gov (United States)

    Minor, J. E.

    1980-01-01

    The Seasonal Thermal Energy Storage (STES) Program designed to demonstrate the storage and retrieval of energy on a seasonal basis using heat or cold available from waste or other sources during a surplus period is described. Factors considered include reduction of peak period demand and electric utility load problems and establishment of favorable economics for district heating and cooling systems for commercialization of the technology. The initial thrust of the STES Program toward utilization of ground water systems (aquifers) for thermal energy storage is emphasized.

  13. Thermal conductivity distributed from a Thermal Response Test (TRT in a borehole heat exchanger (BHE

    Directory of Open Access Journals (Sweden)

    A. Blasi

    2012-12-01

    Full Text Available The Thermal Response Test (TRT is the most versatile tool to determine the thermal propriety of the underground for designing and sizing of the borehole heat exchangers (BHE. The TRT permits to get the average thermal conductivity (λ across the whole stratigraphy, the thermal resistance (Rb of the borehole / grout / rocks and the undisturbed temperature of the soil (Tg. The ground temperature is influenced by climate, topographical, geological and hydrological factors. Vertical temperature changes allows to get the relationships with the lithology and especially with the groundwater. Vertical temperature log, acquired during and after the TRT, permits to calculate the distributed thermal conductivity over each stratigraphic interval. This method permits to verify how the different lithologies and the groundwater contribute to the heat exchange in the borehole/ground system, so called geoexchange. The experimental site test indicates that the marls and clayed-marls levels show a higher thermal inertia than the sandstone ones and then lower values of thermal conducivity. The sandstones have a higher thermal conductivity with a rapid cooling and they provide the main contribution to the ground heat exchange. The distributed thermal conductivity is an useful tool for designing the BHE with the best performance, a better economic return and with low environmental impacts.

  14. Regimes of Axisymmetric Flow and Scaling Laws in a Rotating Annulus with Local Convective Forcing

    Directory of Open Access Journals (Sweden)

    Susie Wright

    2017-07-01

    Full Text Available We present a numerical study of axisymmetric flow in a rotating annulus in which local thermal forcing, via a heated annular ring on the outside of the base and a cooled circular disk in the centre of the top surface, drives convection. This new configuration is a variant of the classical thermally-driven annulus, where uniform heating and cooling are applied through the outer and inner sidewalls respectively. The annulus provides an analogue to a planetary circulation and the new configuration, with its more relaxed vertical thermal boundary conditions, is expected to better emulate vigorous convection in the tropics and polar regions as well as baroclinic instability in the mid-latitude baroclinic zone. Using the Met Office/Oxford Rotating Annulus Laboratory (MORALS code, we have investigated a series of equilibrated, two dimensional axisymmetric flows across a large region of parameter space. These are characterized in terms of their velocity and temperature fields. When rotation is applied several distinct flow regimes may be identified for different rotation rates and strengths of differential heating. These regimes are defined as a function of the ratio of the horizontal Ekman layer thickness to the non-rotating thermal boundary layer thickness and are found to be similar to those identified in previous annulus experiments. Convection without rotation is also considered and the scaling of the heat transport with Rayleigh number is calculated. This is then compared with existing work on the classical annulus as well as horizontal and Rayleigh-Bénard convection. As with previous studies on both rotating and non-rotating convection the system’s behaviour is found to be aspect ratio dependent. This dependence is seen in the scaling of the non-rotating Nusselt number and in transitions between regimes in the rotating case although further investigation is required to fully explain these observations.

  15. Tropical forest light regimes in a human-modified landscape.

    Science.gov (United States)

    Fauset, Sophie; Gloor, Manuel U; Aidar, Marcos P M; Freitas, Helber C; Fyllas, Nikolaos M; Marabesi, Mauro A; Rochelle, André L C; Shenkin, Alexander; Vieira, Simone A; Joly, Carlos A

    2017-11-01

    Light is the key energy input for all vegetated systems. Forest light regimes are complex, with the vertical pattern of light within canopies influenced by forest structure. Human disturbances in tropical forests impact forest structure and hence may influence the light environment and thus competitiveness of different trees. In this study, we measured vertical diffuse light profiles along a gradient of anthropogenic disturbance, sampling intact, logged, secondary, and fragmented sites in the biodiversity hot spot of the Atlantic forest, southeast Brazil, using photosynthetically active radiation sensors and a novel approach with estimations of vertical light profiles from hemispherical photographs. Our results show clear differences in vertical light profiles with disturbance: Fragmented forests are characterized by rapid light extinction within their low canopies, while the profiles in logged forests show high heterogeneity and high light in the mid-canopy despite decades of recovery. The secondary forest showed similar light profiles to intact forest, but with a lower canopy height. We also show that in some cases the upper canopy layer and heavy liana infestations can severely limit light penetration. Light extinction with height above the ground and depth below the canopy top was highest in fragmented forest and negatively correlated with canopy height. The novel, inexpensive, and rapid methods described here can be applied to other sites to quantify rarely measured vertical light profiles.

  16. Evolution of the Greek national regime for water resources

    NARCIS (Netherlands)

    Kampa, Eleftheria; Bressers, Johannes T.A.

    2008-01-01

    This paper characterizes and explains the development of the Greek national water regime, based on a framework from institutional resource regime theory. The specific framework combines public resource policies with property rights and operationalizes the concept of integration for resource regimes.

  17. Level-ARCH Short Rate Models with Regime Switching

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    This paper introduces regime switching volatility into level- ARCH models for the short rates of the US, the UK, and Germany. Once regime switching and level effects are included there are no gains from including ARCH effects. It is of secondary importance exactly how the regime switching is spec...

  18. The global nuclear safety regime and its impact in Brazil

    International Nuclear Information System (INIS)

    Almeida, C.

    2004-01-01

    This work describes the Global Nuclear Safety Regime that was established worldwide after the accident at the Tchernobyl nuclear power plant. This regime is composed of biding international safety conventions, globally accepted safety standard, and a voluntary peer review system. The impact of this Global Regime in Brazil is also discussed. (Author)

  19. Enduring ambiguity: Sunni community-Syrian regime dynamics

    NARCIS (Netherlands)

    Donker, T.H.

    2010-01-01

    The paper's central thesis is that authoritarian regimes can benefit from the presence of domestic (Sunni) civil activism; through a social dynamic that creates an incentive for Sunni activists to actively approach regime actors. The article poses that they thereby imply a subservience to the regime

  20. Model for forecasting of monthly average insulation at ground level taking into account the radiation absorption losses crossing atmosphere in the thermal solar applications; Modelo de previsao da insolacao media mensal ao nivel do solo levando em conta a perda por absorcao na atmosfera em aplicacoes solares termicas

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, J.C.; Apolinario, F.R.; Silva, E.P. da [Universidade Estadual de Campinas, SP (Brazil). Lab. de Hidrogenio]. E-mails: joaoc@fem.unicamp.br; rezende@ifi.unicamp.br; lh2ennio@ifi.unicamp.br

    2000-07-01

    The use of the solar energy, for thermal or photovoltaic ends, depends basically on the amount of radiation that reaches the ground in the place where desires to carry through this use, defining the necessary area of the collectors, or panels, that in turn are the main components of the final cost of the system and, therefore, of the viability or not on its use. The incident radiation in the terrestrial surface is minor that one reaches the top of the atmosphere due to the absorption and dispersion factors. The objective of this work is to present a model of forecast the monthly average radiation for ends of use in systems of flat solar collectors for heating water, in the city of Campinas - Sao Paulo, Brazil. This work has been developed by the Hydrogen Laboratory of the Institute of Physics of the UNICAMP, being also used for other applications with solar energy. Based in the radiation data, taken from a local station, a theoretical study was developed to calculate a parameter of loss of radiation when this cross the atmosphere. This Kt loss factor, has basic importance for the knowledge of the effective available energy for use. With this data it is possible to determine, on the basis of the incident radiation in the top of the atmosphere, the value of the radiation on a surface. (author)

  1. Nanosecond Repetitively Pulsed Discharges in Air at Atmospheric Pressure -- Experiment and Theory of Regime Transitions

    Science.gov (United States)

    Pai, David; Lacoste, Deanna; Laux, Christophe

    2009-10-01

    In atmospheric pressure air preheated from 300 to 1000 K, the Nanosecond Repetitively Pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and inter-electrode gap distance) of each discharge regime. Notably, there is a minimum gap distance for the existence of the glow regime that increases with decreasing gas temperature. A theory is developed to describe the Corona-to-Glow (C-G) and Glow-to-Spark (G-S) transitions for NRP discharges. The C-G transition is shown to depend on the Avalanche-to-Streamer Transition (AST) as well as the electric field strength in the positive column. The G-S transition is due to the thermal ionization instability. The minimum gap distance for the existence of the glow regime can be understood by considering that the applied voltage of the AST must be lower than that of the thermal ionization instability. This is a previously unknown criterion for generating glow discharges, as it does not correspond to the Paschen minimum or to the Meek-Raether criterion.

  2. Ground-source heat pump systems in Norway

    International Nuclear Information System (INIS)

    Stene, Joern

    2007-01-01

    The Norwegian ground source heat pump (GSHP) market is reviewed. Boreholes in bedrock are of growing interest for residential systems and of growing interest for larger systems with thermal recharging or thermal energy storage. Ground water is limited to areas where the water has acceptable purity. Challenges and important boundary conditions include 1) high quality GSHP system requires engineering expertise, 2) new building codes and EU directive 'energy performance of buildings.'(2006), and 3) hydronic floor heating systems in 50 percent of new residences (author) (ml)

  3. Convective Replica-Exchange in Ergodic Regimes.

    Science.gov (United States)

    Signorini, Giorgio F; Giovannelli, Edoardo; Spill, Yannick G; Nilges, Michael; Chelli, Riccardo

    2014-03-11

    In a recent article (J. Comput. Chem. 2013, 34, 132-140), convective replica-exchange (convective-RE) has been presented as an alternative to the standard even-odd transition scheme. Computations on systems of various complexity have shown that convective-RE may increase the number of replica round-trips in temperature space with respect to the standard exchange scheme, leading to a more effective sampling of energy basins. Moreover, it has been shown that the method may prevent the formation of bottlenecks in the diffusive walk of replicas through the space of temperature states. By using an ideal temperature-RE model and a classical harmonic-oscillator RE scheme, we study the performances of convective-RE when ergodicity is not broken and convergence of acceptance probabilities is attained. In this dynamic regime, the round-trip ratio between convective and standard-RE is at maximum ∼ 1.5, a value much smaller than that observed in nonergodic simulations. For large acceptance probabilities, the standard-RE outperforms convective-RE. Our observations suggest that convective-RE can safely be used in either ergodic or non-ergodic regimes; however, convective-RE is advantageous only when bottlenecks occur in the state-space diffusion of replicas, or when acceptance probabilities are globally low. We also show that decoupling of the state-space dynamics of the stick replica from the dynamics of the remaining replicas improves the efficiency of convective-RE at low acceptance probability regimes.

  4. The trade regime and the climate regime. Institutional evolution and adaptation

    International Nuclear Information System (INIS)

    Brewer, Thomas L.

    2003-01-01

    This article addresses concerns that the multilateral trade regime centered in the WTO and the emerging climate regime may conflict in ways that could be damaging to either or both. The article discusses the institutional and diplomatic context of these concerns, and it identifies the kinds of issues that are in question. The analysis suggests that there are opportunities for win-win outcomes in the interactions of the two regimes, for instance in the possibility of reducing fossil fuel subsidies. However, there are also problematic areas where they intersect. A core issue-and as yet an unresolved one-is whether and how emission credit trading and other activities envisioned by the Kyoto Protocol would be subject to WTO rules. The resolution of this issue will affect many other issues as well. Additional specific issues about the interactions of particular provisions in WTO agreements and the Kyoto Protocol are analyzed in a subsequent companion article in Climate Policy

  5. Electron acceleration in the bubble regime

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Oliver

    2014-02-03

    The bubble regime of laser-wakefield acceleration has been studied over the recent years as an important alternative to classical accelerators. Several models and theories have been published, in particular a theory which provides scaling laws for acceleration parameters such as energy gain and acceleration length. This thesis deals with numerical simulations within the bubble regime, their comparison to these scaling laws and data obtained from experiments, as well as some specific phenomenona. With a comparison of the scaling laws with numerical results a parameter scan was able to show a large parameter space in which simulation and theory agree. An investigation of the limits of this parameter space revealed boundaries to other regimes, especially at very high (a{sub 0} > 100) and very low laser amplitudes (a{sub 0} < 4). Comparing simulation data with data from experiments concerning laser pulse development and electron energies, it was found that experimental results can be adequately reproduced using the Virtual-Laser-Plasma-Laboratory code. In collaboration with the Institut fuer Optik und Quantenelektronik at the Friedrich-Schiller University Jena synchrotron radiation emitted from the inside of the bubble was investigated. A simulation of the movement of the electrons inside the bubble together with time dependent histograms of the emitted radiation helped to prove that the majority of radiation created during a bubble acceleration originates from the inside of the bubble. This radiation can be used to diagnose the amplitude of oscillation of the trapped electrons. During a further study it was proven that the polarisation of synchrotron radiation from a bubble contains information about the exact oscillation direction. This oscillation was successfully controlled by using either a laser pulse with a tilted pulse front or an asymmetric laser pulse. First results of ongoing studies concerning injecting electrons into an existing bubble and a scheme called

  6. Operation regimes of a dielectric laser accelerator

    Science.gov (United States)

    Hanuka, Adi; Schächter, Levi

    2018-04-01

    We investigate three operation regimes in dielectric laser driven accelerators: maximum efficiency, maximum charge, and maximum loaded gradient. We demonstrate, using a self-consistent approach, that loaded gradients of the order of 1 to 6 [GV/m], efficiencies of 20% to 80%, and electrons flux of 1014 [el/s] are feasible, without significant concerns regarding damage threshold fluence. The latter imposes that the total charge per squared wavelength is constant (a total of 106 per μm2). We conceive this configuration as a zero-order design that should be considered for the road map of future accelerators.

  7. Random nanolasing in the Anderson localized regime

    DEFF Research Database (Denmark)

    Liu, Jin; Garcia, P. D.; Ek, Sara

    2014-01-01

    multiple scattering. The applicability of random lasers has been limited due to multidirectional emission, lack of tunability, and strong mode competition with chaotic fluctuations due to a weak mode confinement. The regime of Anderson localization of light has been proposed for obtaining stable multimode...... random lasing, and initial work concerned macroscopic one-dimensional layered media. Here, we demonstrate on-chip random nanolasers where the cavity feedback is provided by the intrinsic disorder. The strong confinement achieved by Anderson localization reduces the spatial overlap between lasing modes...

  8. Spontaneous quasi single helicity regimes in EXTRAP T2R reversed-field pinch

    Science.gov (United States)

    Frassinetti, L.; Brunsell, P. R.; Drake, J. R.; Menmuir, S.; Cecconello, M.

    2007-11-01

    In recent years, good progress toward a better understanding and control of the plasma performance in reversed-field pinch devices has been made. These improvements consist both of the discovery of spontaneous plasma regimes, termed the quasi single helicity (QSH) regime, in which part of the plasma core is no longer stochastic, and of the development of techniques for active control of plasma instabilities. In this paper, a systematic study of spontaneous QSH in the EXTRAP T2R device [P. R. Brunsell, H. Bergsaker, M. Cecconello et al., Plasma Phys. Control. Fusion 43, 1457 (2001)] is presented. In this device, QSH states can occur spontaneously and it is associated with magnetic and thermal structures. A statistical analysis to determine the most favorable experimental conditions to have a transition to the QSH regime will be presented. The results described here are useful to understand the underlying properties of QSH regimes in view of future applications of the QSH active control in EXTRAP T2R; they are also important to have a comparison with the QSH studied in other devices.

  9. Environmental impact of herbicide regimes used with genetically modified herbicide-resistant maize.

    Science.gov (United States)

    Devos, Yann; Cougnon, Mathias; Vergucht, Sofie; Bulcke, Robert; Haesaert, Geert; Steurbaut, Walter; Reheul, Dirk

    2008-12-01

    With the potential advent of genetically modified herbicide-resistant (GMHR) crops in the European Union, changes in patterns of herbicide use are predicted. Broad-spectrum, non-selective herbicides used with GMHR crops are expected to substitute for a set of currently used herbicides, which might alter the agro-environmental footprint from crop production. To test this hypothesis, the environmental impact of various herbicide regimes currently used with non-GMHR maize in Belgium was calculated and compared with that of possible herbicide regimes applied in GMHR maize. Impacts on human health and the environment were calculated through the pesticide occupational and environmental risk (POCER) indicator. Results showed that the environmental impact of herbicide regimes solely relying on the active ingredients glyphosate (GLY) or glufosinate-ammonium (GLU) is lower than that of herbicide regimes applied in non-GMHR maize. Due to the lower potential of GLY and GLU to contaminate ground water and their lower acute toxicity to aquatic organisms, the POCER exceedence factor values for the environment were reduced approximately by a sixth when GLY or GLU is used alone. However, the environmental impact of novel herbicide regimes tested may be underestimated due to the assumption that active ingredients used with GMHR maize would be used alone. Data retrieved from literature suggest that weed control efficacy is increased and resistance development delayed when GLY or GLU is used together with other herbicides in the GMHR system. Due to the partial instead of complete replacement of currently used herbicide regimes, the beneficial environmental impact of novel herbicide regimes might sometimes be reduced or counterbalanced. Despite the high weed control efficacy provided by the biotechnology-based weed management strategy, neither indirect harmful effects on farmland biodiversity through losses in food resources and shelter, nor shifts in weed communities have been

  10. Change of secondary water regime of Paks NPP. Change of secondary water regime at Unit 2

    International Nuclear Information System (INIS)

    Doma, A.; Patek, G.; Pinter, T.; Bajari, M.; Tilky, P.

    2001-01-01

    The installation of high pH water regime during the 17th cycle of Unit 2 aimed to decrease the amount of transportation inlet of erosion-corrosion products (magnitude) in feedwater to SGs. The resolution of OAH-NBI permitting the installation ordained to make an evaluation of the process. The main conclusions and results are discussed. The high pH water regime proved to be adequate in the case of Unit 2 as well, similarly to Units 3, 4 and 1. (R.P.)

  11. Steady state ventilation regimes in multiple room buildings

    Science.gov (United States)

    Flynn, Morris; Caulfield, Colm-Cille

    2004-11-01

    The ventilation of connected chambers offers a rich variety of flow behaviors. A two-chamber model is considered in which only one of the chambers is thermally forced yet both may communicate with the external environment. If the plume source has a finite volume flux, either chamber may become blocked i.e. completely filled with contaminated fluid. Hence, a steady, naturally ventilated regime is possible only for certain non-dimensional combinations of the effective vent area and the source volume and buoyancy fluxes. Steady state conditions are derived in a manner analogous to Linden, Lane-Serff & Smeed (1990) and Woods, Caulfield & Phillips (2003). Unfortunately, these conditions cannot specify the buoyant layer depth in the unforced room for which the transient evolution toward steady state must also be considered. Results from this analysis (performed in the limiting case of a plume source with zero volume flux) suggest that at steady state, the buoyant layer depth in the unforced chamber may be either larger or smaller than that of the forced chamber.

  12. Flow regime identification methodology with computerized tomography

    International Nuclear Information System (INIS)

    Teixeira, Alberto Ramon Ferreira; Roberty, Nilson Costa

    2010-01-01

    This work presents a flow identification methodology in multiphase system in stratified oil-water-gas regime. The principle is based on detecting the amount of x-rays attenuated by passing through the duct containing the flow. The radiation interacts with the material and the composite duct fluid, causing the intensity of X ray declines. In this study, was used divergent bean into two and three dimensions. In this case we need to know the source position in order to back project the rays accordingly in a divergent way. In three dimensions, the projections discontinuity determination problem is substituted by the projections images contour determination. Each ray generates one algebraic equation. The system may be solved by the least square method or by some algebraic reconstruction technique such as the ART, MART or q-ART algorithms. The experiment shows that with a single view (a source-detector pair) it is possible to obtain information of a flow inside a duct (the attenuation of the radiation beam). However, it is not possible to make the reconstruction of the flow. Then, we use two views, so getting enough information to reconstruct the flow. The results presented show that the technique may be applied in the successfully flow regime identification. (author)

  13. Managing Disagreement: A Defense of "Regime Bias"

    Science.gov (United States)

    Sabl, Andrew

    2011-02-01

    Stein Ringen's theory of democratic purpose cannot do the work expected of it. Ringen's own criteria oscillate between being too vague to be useful (i.e. "freedom") or, when specified more fully, conflicting, so that almost all democracies will seem to be potentially at cross-purposes with themselves rather than their purposes or sub-purposes being mutually reinforcing. This reflects a bigger and more theoretical problem. Disagreement about the purpose of democracy is built into democracy itself. The whole point of many (perhaps all) of our democratic institutions is to arrive at conditionally legitimate decisions in spite of such disagreement. So-called regime bias, i.e. the tendency to assess democracies according to the form and stability of their institutions rather than their results or their ability to serve certain purposes, does not in fact arise from bias. It arises on the contrary from a determination to avoid the bias inherent in giving some-inevitably partisan-ideals of what democracies should do pride of place over others in a scheme of measurement or evaluation. And even a regime-based definition of democracy must itself make simplifying assumptions that elide possible normative controversies over how the democratic game is best played. Vindicating one's preferred set of democratic ideals against alternatives is a completely legitimate enterprise and lends richness to debates within and across democracies. But it is an inherently ideological and political enterprise, not a neutral or scholarly one.

  14. Legal framework of the environmental regulatory regime

    International Nuclear Information System (INIS)

    Black, D.

    1992-01-01

    The growing concern regarding environmental issues has presented a number of new challenges to those exploring and developing the hydrocarbon reserves located on the Newfoundland continental shelf. Not the least of these challenges is the development of new technologies in the harsh environment of the North Atlantic; in addition, these new technologies must be implemented in an existing and ever-changing regulatory regime. The legal framework of the environmental regulatory regime relating to offshore development in Canada is reviewed along with some of the more important legislation involved in regulating environmental issues in the offshore area. The legal basis for exploration, development, and management of resources located on the Newfoundland continental shelf is the Canada-Newfoundland Accord on Joint Management of Offshore Oil and Gas Resources off Newfoundland and Labrador. Administration of the Accord is the responsibility of the Canada-Newfoundland Offshore Petroleum Board. To be able to apply Canadian laws to the continental shelf, legislation was passed including the Canadian Laws Offshore Application Act as well as the Act implementing the Accord. The latter gives the Offshore Petroleum Board authority to regulate all stages involved in bringing an oil pool to production, such as granting of licenses and work authorizations. Granting of such licenses and authorizations is subject to compliance with environmental requirements, and there are provisions against certain environmental offenses such as spills. Other federal legislation applicable to the offshore includes the Canada Shipping Act and the Canadian Environmental Protection Act

  15. Characterizing multistationarity regimes in biochemical reaction networks.

    Directory of Open Access Journals (Sweden)

    Irene Otero-Muras

    Full Text Available Switch like responses appear as common strategies in the regulation of cellular systems. Here we present a method to characterize bistable regimes in biochemical reaction networks that can be of use to both direct and reverse engineering of biological switches. In the design of a synthetic biological switch, it is important to study the capability for bistability of the underlying biochemical network structure. Chemical Reaction Network Theory (CRNT may help at this level to decide whether a given network has the capacity for multiple positive equilibria, based on their structural properties. However, in order to build a working switch, we also need to ensure that the bistability property is robust, by studying the conditions leading to the existence of two different steady states. In the reverse engineering of biological switches, knowledge collected about the bistable regimes of the underlying potential model structures can contribute at the model identification stage to a drastic reduction of the feasible region in the parameter space of search. In this work, we make use and extend previous results of the CRNT, aiming not only to discriminate whether a biochemical reaction network can exhibit multiple steady states, but also to determine the regions within the whole space of parameters capable of producing multistationarity. To that purpose we present and justify a condition on the parameters of biochemical networks for the appearance of multistationarity, and propose an efficient and reliable computational method to check its satisfaction through the parameter space.

  16. Tlatelolco regime and nonproliferation in Latin America

    International Nuclear Information System (INIS)

    Redick, J.R.

    1981-01-01

    The regime established by the Treaty of Tlatelolco supports peace and security in the Latin American region and global nonproliferation efforts. Circumstances leading to the creation of the nuclear-weapon-free zone include careful preparations and negotiations, individual leadership, existence of certain shared cultural and legal traditions of Latin American countries, and the temporary stimulus of the Cuban missile crisis. The lack of overt superpower pressure on Latin America, compared with more turbulent regions, has permitted continued progress toward full realization of the zone. Tlatelolco's negotiating process, as well as the substance of the Treaty, deserve careful consideration relative to other areas. The Treaty enjoys wide international approval, but full support by certain Latin American States (Argentina, Brazil, Chile, Cuba) has been negatively affected by the failure of the US Senate to ratify Tlatelolco's Protocol I. Nuclear programs of Argentina, Brazil, and Mexico are expanding rapidly and these nations are forming linkages with West European countries, rather than the United States. The May 1980 Argentine-Brazilian nuclear agreement foresees significant cooperation between the two nation's nuclear energy commissions and more coordinated resistance to the nuclear supplier countries. Argentine-Brazilian nuclear convergence and the response accorded to it by the United States will have significant implications for the future of the Tlatelolco regime and nonproliferation in Latin America. 52 references

  17. Elastic regimes of subisostatic athermal fiber networks

    Science.gov (United States)

    Licup, A. J.; Sharma, A.; MacKintosh, F. C.

    2016-01-01

    Athermal models of disordered fibrous networks are highly useful for studying the mechanics of elastic networks composed of stiff biopolymers. The underlying network architecture is a key aspect that can affect the elastic properties of these systems, which include rich linear and nonlinear elasticity. Existing computational approaches have focused on both lattice-based and off-lattice networks obtained from the random placement of rods. It is not obvious, a priori, whether the two architectures have fundamentally similar or different mechanics. If they are different, it is not clear which of these represents a better model for biological networks. Here, we show that both approaches are essentially equivalent for the same network connectivity, provided the networks are subisostatic with respect to central force interactions. Moreover, for a given subisostatic connectivity, we even find that lattice-based networks in both two and three dimensions exhibit nearly identical nonlinear elastic response. We provide a description of the linear mechanics for both architectures in terms of a scaling function. We also show that the nonlinear regime is dominated by fiber bending and that stiffening originates from the stabilization of subisostatic networks by stress. We propose a generalized relation for this regime in terms of the self-generated normal stresses that develop under deformation. Different network architectures have different susceptibilities to the normal stress but essentially exhibit the same nonlinear mechanics. Such a stiffening mechanism has been shown to successfully capture the nonlinear mechanics of collagen networks.

  18. Strengthening the non proliferation regime: French views

    International Nuclear Information System (INIS)

    Delaune, P.

    2013-01-01

    3 main issues can be identified in the French policy concerning the backing of non proliferation: 1) responding resolutely to proliferation crises, 2) reinforcing substantive efforts to prevent and impede proliferation, and 3) strengthening the non-proliferation regime. The first issue is very important because combating proliferation is vital to the security of all. Concerning the second issue, France attaches particular importance to strengthening specific measures to prevent and check proliferation. Let me mention a few proposals that we put forward: exports need to be controlled more effectively, proliferation activities have to be criminalized, or the development of proliferation-resistant technologies should be supported. Concerning the third issue it means the strengthening of the non-proliferation regime, France proposes several means: -) aiming at the universalization of the additional protocol; -) ensuring that the Agency continues to have sufficient human, financial and technical resources to fulfill its verification mission effectively; -) encouraging the IAEA to make full use of the authority available to it; -) enhancing the use of information relevant to the delivery of the IAEA mandate; and -) sharing more accurate information concerning the breaches of commitments that happen. The paper is followed by the slides of the presentation. (A.C.)

  19. Three novel tokamak plasma regimes in TFTR

    International Nuclear Information System (INIS)

    Furth, H.P.

    1985-10-01

    Aside from extending ''standard'' ohmic and neutral beam heating studies to advanced plasma parameters, TFTR has encountered a number of special plasma regimes that have the potential to shed new light on the physics of tokamak confinement and the optimal design of future D-T facilities: (1) High-powered, neutral beam heating at low plasma densities can maintain a highly reactive hot-ion population (with quasi-steady-state beam fueling and current drive) in a tokamak configuration of modest bulk-plasma confinement requirements. (2) Plasma displacement away from limiter contact lends itself to clarification of the role of edge-plasma recycling and radiation cooling within the overall pattern of tokamak heat flow. (3) Noncentral auxiliary heating (with a ''hollow'' power-deposition profile) should serve to raise the central tokamak plasma temperature without deterioration of central region confinement, thus facilitating the study of alpha-heating effects in TFTR. The experimental results of regime (3) support the theory that tokamak profile consistency is related to resistive kink stability and that the global energy confinement time is determined by transport properties of the plasma edge region

  20. Three novel tokamak plasma regimes in TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Furth, H.P.

    1985-10-01

    Aside from extending ''standard'' ohmic and neutral beam heating studies to advanced plasma parameters, TFTR has encountered a number of special plasma regimes that have the potential to shed new light on the physics of tokamak confinement and the optimal design of future D-T facilities: (1) High-powered, neutral beam heating at low plasma densities can maintain a highly reactive hot-ion population (with quasi-steady-state beam fueling and current drive) in a tokamak configuration of modest bulk-plasma confinement requirements. (2) Plasma displacement away from limiter contact lends itself to clarification of the role of edge-plasma recycling and radiation cooling within the overall pattern of tokamak heat flow. (3) Noncentral auxiliary heating (with a ''hollow'' power-deposition profile) should serve to raise the central tokamak plasma temperature without deterioration of central region confinement, thus facilitating the study of alpha-heating effects in TFTR. The experimental results of regime (3) support the theory that tokamak profile consistency is related to resistive kink stability and that the global energy confinement time is determined by transport properties of the plasma edge region.

  1. Thermal State-of-Charge in Solar Heat Receivers

    Science.gov (United States)

    Hall, Carsie, A., III; Glakpe, Emmanuel K.; Cannon, Joseph N.; Kerslake, Thomas W.

    1998-01-01

    A theoretical framework is developed to determine the so-called thermal state-of-charge (SOC) in solar heat receivers employing encapsulated phase change materials (PCMS) that undergo cyclic melting and freezing. The present problem is relevant to space solar dynamic power systems that would typically operate in low-Earth-orbit (LEO). The solar heat receiver is integrated into a closed-cycle Brayton engine that produces electric power during sunlight and eclipse periods of the orbit cycle. The concepts of available power and virtual source temperature, both on a finite-time basis, are used as the basis for determining the SOC. Analytic expressions for the available power crossing the aperture plane of the receiver, available power stored in the receiver, and available power delivered to the working fluid are derived, all of which are related to the SOC through measurable parameters. Lower and upper bounds on the SOC are proposed in order to delineate absolute limiting cases for a range of input parameters (orbital, geometric, etc.). SOC characterization is also performed in the subcooled, two-phase, and superheat regimes. Finally, a previously-developed physical and numerical model of the solar heat receiver component of NASA Lewis Research Center's Ground Test Demonstration (GTD) system is used in order to predict the SOC as a function of measurable parameters.

  2. Thermal systems; Systemes thermiques

    Energy Technology Data Exchange (ETDEWEB)

    Lalot, S. [Valenciennes Univ. et du Hainaut Cambresis, LME, 59 (France); Lecoeuche, S. [Ecole des Mines de Douai, Dept. GIP, 59 - Douai (France)]|[Lille Univ. des Sciences et Technologies, 59 - Villeneuve d' Ascq (France); Ahmad, M.; Sallee, H.; Quenard, D. [CSTB, 38 - Saint Martin d' Heres (France); Bontemps, A. [Universite Joseph Fourier, LEGI/GRETh, 38 - Grenoble (France); Gascoin, N.; Gillard, P.; Bernard, S. [Laboratoire d' Energetique, Explosion, Structure, 18 - Bourges (France); Gascoin, N.; Toure, Y. [Laboratoire Vision et Robotique, 18 - Bourges (France); Daniau, E.; Bouchez, M. [MBDA, 18 - Bourges (France); Dobrovicescu, A.; Stanciu, D. [Bucarest Univ. Polytechnique, Faculte de Genie Mecanique (Romania); Stoian, M. [Reims Univ. Champagne Ardenne, Faculte des Sciences, UTAP/LTM, 51 (France); Bruch, A.; Fourmigue, J.F.; Colasson, S. [CEA Grenoble, Lab. Greth, 38 (France); Bontemps, A. [Universite Joseph Fourier, LEGI/GRETh, 38 - Grenoble (France); Voicu, I.; Mare, T.; Miriel, J. [Institut National des Sciences Appliquees (INSA), LGCGM, IUT, 35 - Rennes (France); Galanis, N. [Sherbrooke Univ., Genie Mecanique, QC (Canada); Nemer, M.; Clodic, D. [Ecole des Mines de Paris, Centre Energetique et Procedes, 75 (France); Lasbet, Y.; Auvity, B.; Castelain, C.; Peerhossaini, H. [Nantes Univ., Ecole Polytechnique, Lab. de Thermocinetiquede Nantes, UMR-CNRS 6607, 44 (France)

    2005-07-01

    This session about thermal systems gathers 26 articles dealing with: neural model of a compact heat exchanger; experimental study and numerical simulation of the thermal behaviour of test-cells with walls made of a combination of phase change materials and super-insulating materials; hydraulic and thermal modeling of a supercritical fluid with pyrolysis inside a heated channel: pre-dimensioning of an experimental study; energy analysis of the heat recovery devices of a cryogenic system; numerical simulation of the thermo-hydraulic behaviour of a supercritical CO{sub 2} flow inside a vertical tube; mixed convection inside dual-tube exchangers; development of a nodal approach with homogenization for the simulation of the brazing cycle of a heat exchanger; chaotic exchanger for the cooling of low temperature fuel cells; structural optimization of the internal fins of a cylindrical generator; a new experimental approach for the study of the local boiling inside the channels of exchangers with plates and fins; experimental study of the flow regimes of boiling hydrocarbons on a bundle of staggered tubes; energy study of heat recovery exchangers used in Claude-type refrigerating systems; general model of Carnot engine submitted to various operating constraints; the free pistons Stirling cogeneration system; natural gas supplied cogeneration system with polymer membrane fuel cell; influence of the CRN coating on the heat flux inside the tool during the wood unrolling process; transport and mixture of a passive scalar injected inside the wake of a Ahmed body; control of a laser welding-brazing process by infrared thermography; 2D self-adaptative method for contours detection: application to the images of an aniso-thermal jet; exergy and exergy-economical study of an 'Ericsson' engine-based micro-cogeneration system; simplified air-conditioning of telephone switching equipments; parametric study of the 'low-energy' individual dwelling; brief synthesis of

  3. Thermal comfort

    DEFF Research Database (Denmark)

    d’Ambrosio Alfano, Francesca Romana; Olesen, Bjarne W.; Palella, Boris Igor

    2014-01-01

    Thermal comfort is one of the most important aspects of the indoor environmental quality due to its effects on well-being, people's performance and building energy requirements. Its attainment is not an easy task requiring advanced design and operation of building and HVAC systems, taking...... and operators to navigate the complex and varied world of standards in the field of thermal environment for improving indoor environmental quality and energy saving. The examples discussed in the paper will also be useful for the standardization, leading to harmonized documents more readable for all users....... into account all parameters involved. Even though thermal comfort fundamentals are consolidated topics for more than forty years, often designers seem to ignore or apply them in a wrong way. Design input values from standards are often considered as universal values rather than recommended values to be used...

  4. Uranium isotopes in ground water as a prospecting technique

    International Nuclear Information System (INIS)

    Cowart, J.B.; Osmond, J.K.

    1980-02-01

    The isotopic concentrations of dissolved uranium were determined for 300 ground water samples near eight known uranium accumulations to see if new approaches to prospecting could be developed. It is concluded that a plot of 234 U/ 238 U activity ratio (A.R.) versus uranium concentration (C) can be used to identify redox fronts, to locate uranium accumulations, and to determine whether such accumulations are being augmented or depleted by contemporary aquifer/ground water conditions. In aquifers exhibiting flow-through hydrologic systems, up-dip ground water samples are characterized by high uranium concentration values (> 1 to 4 ppB) and down-dip samples by low uranium concentration values (less than 1 ppB). The boundary between these two regimes can usually be identified as a redox front on the basis of regional water chemistry and known uranium accumulations. Close proximity to uranium accumulations is usually indicated either by very high uranium concentrations in the ground water or by a combination of high concentration and high activity ratio values. Ground waters down-dip from such accumulations often exhibit low uranium concentration values but retain their high A.R. values. This serves as a regional indicator of possible uranium accumulations where conditions favor the continued augmentation of the deposit by precipitation from ground water. Where the accumulation is being dispersed and depleted by the ground water system, low A.R. values are observed. Results from the Gulf Coast District of Texas and the Wyoming districts are presented

  5. Resonance parallel viscosity in the banana regime in poloidally rotating tokamak plasmas

    International Nuclear Information System (INIS)

    Shaing, K.C.; Hsu, C.T.; Dominguez, N.

    1994-01-01

    Parallel viscosity in the banana regime in a poloidally (ExB) rotating tokamak plasma is calculated to include the effects of orbit squeezing and to allow the poloidal ExB Mach number M p to have a value of order unity. Here, E is the electric field and B is the magnetic field. The effects of orbit squeezing not only modify the size of the particle orbit, but also change the fraction of poloidally trapped particles. Resonance between the particle parallel (to B) speed u and the poloidal component of the ExB velocity can only occur for those particles with energy (v/v t ) 2 >M 2 p (with v the particle speed and v t the thermal speed). Thus, the resonance parallel plasma viscosity in the banana regime decreases exponentially with M 2 p when M 2 p ≥1, and has a local maximum of M 2 p ∼1

  6. Fiscal Policy and Welfare under Different Exchange Rate Regimes

    DEFF Research Database (Denmark)

    Østrup, Finn

    , and secondbecause the government's inclination to expand government spending is affectedby inflation which depends on the exchange rate regime. At low rates of inflation,the government is inclined to set a higher level of government spending under afixed exchange rate regime than under a floating exchange rate...... a representativeindividual's utility, it is demonstrated that there are differences betweenexchange rate regimes with respect to the level of government spending. Thesedifferences arise first because a rise in government spending affects macroeconomicvariables differently under different exchange rate regimes...... regime in whichthe monetary authority optimises preferences which include an employment targetand an inflation target. As government spending affects the representativeindividual's utility, the choice of exchange rate regime has an impact on welfare.Keywords: exchange rate regimes; fiscal policy...

  7. Cointegration and causal linkages in fertilizer markets across different regimes

    Science.gov (United States)

    Lahmiri, Salim

    2017-04-01

    Cointegration and causal linkages among five different fertilizer markets are investigated during low and high market regimes. The database includes prices of rock phosphate (RP), triple super phosphate (TSP), diammonium phosphate (DAP), urea, and potassium chloride (PC). It is found that fertilizer markets are closely linked to each other during low and high regimes; and, particularly during high regime (after 2007 international financial crisis). In addition, there is no evidence of bidirectional linear relationship between markets during low and high regime time periods. Furthermore, all significant linkages are only unidirectional. Moreover, some causality effects have emerged during high regime. Finally, the effect of an impulse during high regime time period persists longer and is stronger than the effect of an impulse during low regime time period (before 2007 international financial crisis).

  8. Coshcous turbulence and its thermalization

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Jian-zhou [Los Alamos National Laboratory; Taylor, Mark [SNL

    2008-01-01

    Dissipation rate {mu}[cosh(k/k{sub c}) - 1] in Fourier space, which reduces to the Newtonian viscosity dissipation rate {nu}k{sup 2} for small k/k{sub c}, can be scaled to make a hydrodynamic system either actually or potentially converge to its Galerkin truncation. The former case acquires convergence to the truncation at a finite wavenumber k{sub G}; the latter realizes as the wavenumber grows to infinity. Intermittency reduction and vitiation of extended self-similarity (ESS) in the partially thermalized regime of turbulence are confirmed and clarified. Onsager's pictures of intermittent versus nonintermittent flows are visualized from thermalized numerical fields, showing cleanly spotty versus mistily uniform properties, the latter of which destroys self-organization and so the ESS property.

  9. Matrix thermalization

    Energy Technology Data Exchange (ETDEWEB)

    Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Evnin, Oleg [Department of Physics, Faculty of Science, Chulalongkorn University, Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand); Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Nguyen, Kévin [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium)

    2017-02-08

    Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.

  10. Grounding of space structures

    Science.gov (United States)

    Bosela, P. A.; Fertis, D. G.; Shaker, F. J.

    1992-01-01

    Space structures, such as the Space Station solar arrays, must be extremely light-weight, flexible structures. Accurate prediction of the natural frequencies and mode shapes is essential for determining the structural adequacy of components, and designing a controls system. The tension pre-load in the 'blanket' of photovoltaic solar collectors, and the free/free boundary conditions of a structure in space, causes serious reservations on the use of standard finite element techniques of solution. In particular, a phenomenon known as 'grounding', or false stiffening, of the stiffness matrix occurs during rigid body rotation. This paper examines the grounding phenomenon in detail. Numerous stiffness matrices developed by others are examined for rigid body rotation capability, and found lacking. A force imbalance inherent in the formulations examined is the likely cause of the grounding problem, suggesting the need for a directed force formulation.

  11. Ground motion predictions

    International Nuclear Information System (INIS)

    Loux, P.C.

    1969-01-01

    Nuclear generated ground motion is defined and then related to the physical parameters that cause it. Techniques employed for prediction of ground motion peak amplitude, frequency spectra and response spectra are explored, with initial emphasis on the analysis of data collected at the Nevada Test Site (NTS). NTS postshot measurements are compared with pre-shot predictions. Applicability of these techniques to new areas, for example, Plowshare sites, must be questioned. Fortunately, the Atomic Energy Commission is sponsoring complementary studies to improve prediction capabilities primarily in new locations outside the NTS region. Some of these are discussed in the light of anomalous seismic behavior, and comparisons are given showing theoretical versus experimental results. In conclusion, current ground motion prediction techniques are applied to events off the NTS. Predictions are compared with measurements for the event Faultless and for the Plowshare events, Gasbuggy, Cabriolet, and Buggy I. (author)

  12. Thermal stress relieving of dilute uranium alloys

    International Nuclear Information System (INIS)

    Eckelmeyer, K.H.

    1981-01-01

    The kinetics of thermal stress relieving of uranium - 2.3 wt % niobium, uranium - 2.0 wt % molybdenum, and uranium - 0.75 wt % titanium are reported and discussed. Two temperature regimes of stress relieving are observed. In the low temperature regime (T 0 C) the process appears to be controlled by an athermal microplasticity mechanism which can be completely suppressed by prior age hardening. In the high temperature regime (300 0 C 0 C) the process appears to be controlled by a classical diffusional creep mechanism which is strongly dependent on temperature and time. Stress relieving is accelerated in cases where it occurs simultaneously with age hardening. The potential danger of residual stress induced stress corrosion cracking of uranium alloys is discussed

  13. The concept of regime values: Are revitalization and regime change possible?

    NARCIS (Netherlands)

    Overeem, P.

    2015-01-01

    Among the plethora of public values, one special class is that of “regime values.” This notion plays a central role in the constitutional approach to public administration mainly developed by the late John A. Rohr. In this article, an attempt is made to assess the viability of Rohr’s concept of

  14. Modern fire regime resembles historical fire regime in a ponderosa pine forest on Native American land

    Science.gov (United States)

    Amanda B. Stan; Peter Z. Fule; Kathryn B. Ireland; Jamie S. Sanderlin

    2014-01-01

    Forests on tribal lands in the western United States have seen the return of low-intensity surface fires for several decades longer than forests on non-tribal lands. We examined the surface fire regime in a ponderosa pinedominated (Pinus ponderosa) forest on the Hualapai tribal lands in the south-western United States. Using fire-scarred trees, we inferred temporal (...

  15. Do housing regimes matter? : Assessing the concept of housing regimes through configurations of housing outcomes

    NARCIS (Netherlands)

    Dewilde, C.L.

    2017-01-01

    Based on a conceptualisation of de-commodification as the right to decent and affordable housing, we assessed to what extent this right is realised for low-to-moderate-income owners and renters across Western European housing regimes in 1995 and 2012. If differences in the social production of

  16. Qubit-oscillator systems in the ultrastrong-coupling regime and their potential for preparing nonclassical states

    Science.gov (United States)

    Nori, Franco; Ashhab, Sahel

    2011-03-01

    We consider a system composed of a two-level system (i.e. a qubit) and a harmonic oscillator in the ultrastrong-coupling regime, where the coupling strength is comparable to the qubit and oscillator energy scales. We explore the possibility of preparing nonclassical states in this system, especially in the ground state of the combined system. The nonclassical states that we consider include squeezed states, Schrodinger-cat states and entangled states. We also analyze the nature of the change in the ground state as the coupling strength is increased, going from a separable ground state in the absence of coupling to a highly entangled ground state in the case of very strong coupling. Reference: S. Ashhab and F. Nori, Phys. Rev. A 81, 042311 (2010). We thank support from DARPA, AFOSR, NSA, LPS, ARO, NSF, MEXT, JSPS, FIRST, and JST.

  17. Precipitation regimes over central Greenland inferred from 5 years of ICECAPS observations

    Directory of Open Access Journals (Sweden)

    C. Pettersen

    2018-04-01

    Full Text Available A novel method for classifying Arctic precipitation using ground based remote sensors is presented. Using differences in the spectral variation of microwave absorption and scattering properties of cloud liquid water and ice, this method can distinguish between different types of snowfall events depending on the presence or absence of condensed liquid water in the clouds that generate the precipitation. The classification reveals two distinct, primary regimes of precipitation over the Greenland Ice Sheet (GIS: one originating from fully glaciated ice clouds and the other from mixed-phase clouds. Five years of co-located, multi-instrument data from the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at Summit (ICECAPS are used to examine cloud and meteorological properties and patterns associated with each precipitation regime. The occurrence and accumulation of the precipitation regimes are identified and quantified. Cloud and precipitation observations from additional ICECAPS instruments illustrate distinct characteristics for each regime. Additionally, reanalysis products and back-trajectory analysis show different synoptic-scale forcings associated with each regime. Precipitation over the central GIS exhibits unique microphysical characteristics due to the high surface elevations as well as connections to specific large-scale flow patterns. Snowfall originating from the ice clouds is coupled to deep, frontal cloud systems advecting up and over the southeast Greenland coast to the central GIS. These events appear to be associated with individual storm systems generated by low pressure over Baffin Bay and Greenland lee cyclogenesis. Snowfall originating from mixed-phase clouds is shallower and has characteristics typical of supercooled cloud liquid water layers, and slowly propagates from the south and southwest of Greenland along a quiescent flow above the GIS.

  18. Study and optimization of operating regimes of NPP district heating system

    International Nuclear Information System (INIS)

    Bunin, V.S.; Vasil'ev, M.K.; Kudryavtsev, A.A.; Gorbashev, Yu.B.; Gadzhij, V.M.

    1980-01-01

    Thermal tests of the system with two reactors and four turbines have been carried out for the purpose of verification of operating regimes of the NPP district heating system with boiling single-curcuit RBMK-1000 reactors and K-500-65/3000 turbines. The system is designed for heat supply of habitable settlement and industrial site. The data processing have been carried out by the BESM-6 computer representing distributions of heat flow, steam, water and their parameters and determining the main energy indices of the system. Calculations of the system operating regime variables during the year have been carried out with the help of this program. It has been expected that the system provided heat consumption of 232 MW at calculated regime of thermal loading of the district, temperature regime of the system water of 130/170 deg C, relative load of hot water supply of 0.2 and duration of heating period of 4800 h. Calculations demonstrated that distric heat supply by NPP allowed one to supplant about 85 thous. of reference fuel/year of organic fuel. About 63 thous. of reference fuel/year are required for compensation of decrease of electric energy production in a condensation cycle. It has been also shown, that replacing the four-stroke system heaters by one-stroke heaters permits to drop system water underheating 1.5 times and, respectively, electric energy underproduction to 72 mln Mj (20 mln, kWxh). It produces additional economy of 6.6 thous. reference fuel/year. Calculations of its heat system have been conducted in order to determine the influence of water consumption in an intermediate circuit on the system efficiency. It has been shown that with the increase of water consumption energy power losses decrease. Thus, the above studied have demonstrated that the use of the single-circuit NPP district heating systems leads to considerable economy of fuel

  19. Finite Element Determination of Thermal Conductivity of SiAlON Ceramics Using Sem Images

    OpenAIRE

    Uzun, İbrahim; Pehlivanlı, Zühtü; Doğan, Battal

    2009-01-01

    The thermal conductivity for SiAlON ceramics which are used as a cutting tool material in manufacturing industry has been investigated experimentally, theoretically, and finally numerically. In the experiments, the flash technique was used to determine the thermal conductivity by using the measured thermal diffusion coefficient data in the unsteady regime. Using Maxwell’s, serial, and parallel analytical models, the theoretical thermal conductivities have been determined.For the numerical stu...

  20. A Hydrogen Containment Process for Nuclear Thermal Engine Ground testing

    Science.gov (United States)

    Wang, Ten-See; Stewart, Eric; Canabal, Francisco

    2016-01-01

    The objective of this study is to propose a new total hydrogen containment process to enable the testing required for NTP engine development. This H2 removal process comprises of two unit operations: an oxygen-rich burner and a shell-and-tube type of heat exchanger. This new process is demonstrated by simulation of the steady state operation of the engine firing at nominal conditions.