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Sample records for thermal alteration

  1. Luminescence of thermally altered human skeletal remains

    NARCIS (Netherlands)

    Krap, Tristan; Nota, Kevin; Wilk, Leah; van de Goot, Frank; Ruijter, Jan; Duijst, Wilma; Oostra, Roelof Jan

    2017-01-01

    Literature on luminescent properties of thermally altered human remains is scarce and contradictory. Therefore, the luminescence of heated bone was systemically reinvestigated. A heating experiment was conducted on fresh human bone, in two different media, and cremated human remains were recovered

  2. Magmatism significantly alters the thermal structure of the wedge

    Science.gov (United States)

    Rees Jones, D. W.; Katz, R. F.; Rudge, J. F.; Tian, M.

    2016-12-01

    The temperature structure of the mantle wedge is typically modelled as a balance between thermal diffusion and advection by the solid mantle [e.g., 1]. The thermal state of the wedge promotes melting and melt transport in the natural system, but the thermal consequences of these processes have been neglected from previous models. We show that advective transport of sensible and latent heat by liquid magma can locally alter the temperature structure from canonical models by up to 200K. Liquids are liberated from the subducting slab by de-volatilization reactions. They trigger melting and become silicic en route to the surface, where they cause arc volcanism. These liquids transport heat advectively, and consume or supply latent heat as they melt or freeze. To analyse these effects, we parameterise melting in the presence of volatile species. We combine this with a one-dimensional "melting-column model," previously used to understand mid-ocean ridge volcanism. Our calculations highlight the thermal and chemical response to melt transport across the mantle wedge. Finally, we solve two-dimensional geodynamic models with a prescribed slab flux [2]. These models allow us to identify the most thermally significant fluxes of melt in the system. Perturbations of 200K are found at the base of the overriding lithosphere. This thermal signature of melt migration should be considered when interpreting heat flow, petrologic and seismic data [e.g., 3]. Such a thermal perturbation is likely to affect the chemistry of arc volcanoes, the solid mantle flow and, perhaps, the location of the volcanos themselves [4]. [1] van Keken, P. E., Currie, C., King, S. D., Behn, M. D., Cagnioncle, A., He, J., et al. (2008). A community benchmark for subduction zone modeling. PEPI, doi:10.1016/j.pepi.2008.04.015 [2] Wilson, C. R., Spiegelman, M., van Keken, P. E., & Hacker, B. R. (2014). Fluid flow in subduction zones: The role of solid rheology and compaction pressure. EPSL, doi:10.1016/j

  3. Hydrocarbon generation by thermal alteration of kerogen from different sediments

    Energy Technology Data Exchange (ETDEWEB)

    Ishiwatari, R.; Rohrback, B.G.; Kaplan, I.R.

    1978-04-01

    Kerogen samples from three recent sediments (Tanner basin, Santa Barbara basin, and Banderas Bay) were heated for 24 hours at temperatures ranging from 150 to 410/sup 0/C. The volatile, liquid, and solid residue products of thermal alteration were then analyzed. A comparison of the hydrocarbon generating potential indicates greatest liquid product yields from the predominantly marine source organic material of Tanner basin and the smallest yields from the terrestrially originating source material of Banderas Bay. The nature of the chemical changes described (atomic ratios of H/C and N/C, electron spin resonance data, volatiles lost, n-alkanes generated, and odd-even preference ratio) may be useful in constructing source and maturation histories.

  4. Thermal Alteration of CI and CM Chondrites: Mineralogical Changes and Metamorphic Temperatures

    Science.gov (United States)

    King, A. J.; Schofield, P. F.; Russell, S. S.

    2015-07-01

    Modal mineralogy, H2O abundances and spectral features are used to constrain the origin of thermally altered CI and CM chondrites. Heterogeneous heating was probably caused by impact shocks and affected the surfaces of many C-type asteroids.

  5. Thermal Stimulation Alters Cervical Spinal Cord Functional Connectivity in Humans.

    Science.gov (United States)

    Weber, Kenneth A; Sentis, Amy I; Bernadel-Huey, Olivia N; Chen, Yufen; Wang, Xue; Parrish, Todd B; Mackey, Sean

    2018-01-15

    The spinal cord has an active role in the modulation and transmission of the neural signals traveling between the body and the brain. Recent advancements in functional magnetic resonance imaging (fMRI) have made the in vivo examination of spinal cord function in humans now possible. This technology has been recently extended to the investigation of resting state functional networks in the spinal cord, leading to the identification of distinct patterns of spinal cord functional connectivity. In this study, we expand on the previous work and further investigate resting state cervical spinal cord functional connectivity in healthy participants (n = 15) using high resolution imaging coupled with both seed-based functional connectivity analyses and graph theory-based metrics. Within spinal cord segment functional connectivity was present between the left and right ventral horns (bilateral motor network), left and right dorsal horns (bilateral sensory network), and the ipsilateral ventral and dorsal horns (unilateral sensory-motor network). Functional connectivity between the spinal cord segments was less apparent with the connectivity centered at the region of interest and spanning spinal cord functional network was demonstrated to be state-dependent as thermal stimulation of the right ventrolateral forearm resulted in significant disruption of the bilateral sensory network, increased network global efficiency, and decreased network modularity. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  6. A Propensity for n-omega-Amino Acids in Thermally-Altered Antarctic Meteorites

    Science.gov (United States)

    Burton, Aaron S.; Elsila, Jamie E.; Callahan, Michael P.; Martin, Mildred G.; Glavin, Daniel P.; Johnson, Natasha M.; Dworkin, Jason P.

    2012-01-01

    Carbonaceous meteorites are known to contain a wealth of indigenous organic molecules, including amino acids, which suggests that these meteorites could have been an important source of prebiotic organic material during the origins of life on Earth and possibly elsewhere. We report the detection of extraterrestrial amino acids in thermally-altered type 3 CV and CO carbonaceous chondrites and ureilites recovered from Antarctica. The amino acid concentrations of the thirteen Antarctic meteorites were generally less abundant than in more amino acid-rich CI, CM, and CR carbonaceous chondrites that experienced much lower temperature aqueous alteration on their parent bodies. In contrast to low-temperature aqueously-altered meteorites that show complete structural diversity in amino acids formed predominantly by Strecker-cyanohydrin synthesis, the thermally-altered meteorites studied here are dominated by small, straight-chain, amine terminal (n-omega-amino) amino acids that are not consistent with Strecker formation. The carbon isotopic ratios of two extraterrestrial n-omega-amino acids measured in one of the CV chondrites are consistent with C-13-depletions observed previously in hydrocarbons produced by Fischer-Tropsch type reactions. The predominance of n-omega-amino acid isomers in thermally-altered meteorites hints at cosmochemical mechanisms for the preferential formation and preservation of a small subset of the possible amino acids.

  7. Growing Algae Alter Spectroscopic Characteristics and Chlorine Reactivity of Dissolved Organic Matter from Thermally-Altered Forest Litters.

    Science.gov (United States)

    Tsai, Kuo-Pei; Chow, Alex T

    2016-08-02

    Previous studies demonstrated that wildfires alter spectroscopic characteristics of terrestrial dissolved organic matter (DOM) and increase specific disinfection byproduct formation potential (SDBP-FP). However, it is unclear whether characteristics of thermally altered DOM (TA-DOM) are altered by biogeochemical processes (e.g., transformed by growing algae) before entering water treatment facilities. The freshwater green algae Pseudokirchneriella subcapitata and blue-green algae Microcystis aeruginosa were separately incubated in the mixture of cultural medium and pine (Pinus palustris) litter-derived TA-DOMs (50 °C, 250 °C, and 400 °C) over 7 days to demonstrate the effects of algal growth on alterations in SDBP-FP. TA-DOM optical characteristics and SDBP-FP were quantified by absorption and fluorescence spectroscopy and chlorination-based DBP-FP experiments. After the inoculation with P. subcapitata, TA-DOM aromaticity (indicated by SUVA254) increased from 1.19 to 1.90 L/mg/m for 50 °C-extract but decreased from 4.95 to 3.75 L/mg/m for 400 °C-extract. The fraction of tyrosine-like components decreased from 25.9 to 9.3% for 50 °C-extract but increased from 0.9 to 1.3% for 400 °C-extract. Same patterns were also observed for M. aeruginosa. Growing algae generally increased chlorine reactivities and formations of trihalomethanes, haloacetonitriles, chloral hydrate, and haloketones. Our data suggest that the biodegradable dissolved organic carbon in TA-DOM decreases as fire intensity (i.e., temperature) increases. Postfire algal blooms can increase chlorine reactivity of fire-affected terrestrial DOM for DBP formation.

  8. Hydrothermal alteration at the Roosevelt Hot Springs thermal area, Utah: Petrographic characterization of the alteration to 2 kilometers depth

    Energy Technology Data Exchange (ETDEWEB)

    Ballantyne, J.M.; Parry, W.T.

    1978-04-01

    Hydrothermal alteration in drill cuttings from Thermal Power drillhole 14-2, Roosevelt Hot Springs Thermal area, has been studied petrographically. The hole is sited in alluvium approximately 1.6 km southeast of the old Resort and was rotary drilled to a depth of 1866.0 m. The exact hole location is 2310 FNL, 350 FWL, Sec. 2, Twp 27S, Rge 9W, elevation 1908.5 m. Core was extracted from 792.5 to 795.5 m. Thin sections were made from samples at 15.2 m intervals of drill cuttings collected at 1.5 or 3.0 m intervals during drilling. Thin sections were made of 1.5 or 3.0 m intervals from 274.3 to 304.8 m, 487.9 to 581.2 m, and 868.7 to 899.2 m. These intervals were chosen for close spaced sampling on the basis of increases in temperature, porosity, conductivity and acoustic velocity shown in geophysical logs. A total of 153 thin sections of cuttings were made, and an additional 9 sections were made from the core. Depths of thin section samples are listed in the appendix. A visual estimate of the percentage of each rock type was made for each thin section.

  9. Thermally altered palagonitic tephra - A spectral and process analog to the soil and dust of Mars

    Science.gov (United States)

    Bell, James F., III; Morris, Richard V.; Adams, John B.

    1993-01-01

    Six palagonitic soil samples (PH-1 through PH-6) which were collected at 30-cm intervals from a lava slab on Mauna Kea, Hawaii, are studied. The samples present an alteration sequence caused by heating during emplacement of molten lava over a preexisting tephra cone. Techniques employed include visible and near-IUR spectroscopy, Moessbauer spectroscopy, and magnetic analysis. The four samples closest to the slab (PH-1 through PH-4) were strongly altered in response to heating during its emplacement; their iron oxide mineralogy is dominated by nanophase ferric oxide. The sample adjacent to the slab (PH-1) has a factor of 3 less H2O and contains crystalline hematite and magnetite in addition to nanophase ferric oxide. It is argued that localized thermal alteration events may provide a volumetrically important mechanism for the palagonitization of basaltic glass and the production of crystalline ferric oxides on Mars.

  10. Conodont color alteration index and upper Paleozoic thermal history of the Amazonas Basin, Brazil

    Science.gov (United States)

    Cardoso, Cassiane Negreiros; Sanz-López, Javier; Blanco-Ferrera, Silvia; Lemos, Valesca Brasil; Scomazzon, Ana Karina

    2015-12-01

    The conodont color alteration index (CAI) was determined in elements from core samples of the Frasnian Barreirinha Formation (one well) and of the Pennsylvanian-Permian Tapajós Group (twenty three wells and one limestone quarry) in the Amazonas Basin. The thermal history of the basin is analyzed using the CAI value distribution represented in maps and stratigraphic sections through correlation schemes, and in conjunction with previously published data. The pattern of palaeotemperatures for CAI values of 1.5-3 is coincident with organic matter maturation under a sedimentary overburden providing diagenetic conditions in the oil/gas window. Locally, conodonts show metamorphism (CAI value of 6-7) in relation to the intrusion of diabase bodies in beds including high geothermal gradient evaporites. Microtextural alteration on the surface conodonts commonly shows several types of overgrowth microtextures developed in diagenetic conditions. Locally, recrystallization in conodonts with a high CAI value is congruent with contact metamorphism in relation to Mesozoic intrusions. The CAI values of 1.5 or 2 observed close to the surface in several areas of the basin may be interpreted in relation to a high thermal palaeogradient derived from the magmatic episode or/and to the local denudation of the upper part of the Paleozoic succession prior to this thermal event.

  11. Influence of TRPV1 on diabetes-induced alterations in thermal pain sensitivity

    Directory of Open Access Journals (Sweden)

    Pauza Mary E

    2008-03-01

    Full Text Available Abstract A common complication associated with diabetes is painful or painless diabetic peripheral neuropathy (DPN. The mechanisms and determinants responsible for these peripheral neuropathies are poorly understood. Using both streptozotocin (STZ-induced and transgene-mediated murine models of type 1 diabetes (T1D, we demonstrate that Transient Receptor Potential Vanilloid 1 (TRPV1 expression varies with the neuropathic phenotype. We have found that both STZ- and transgene-mediated T1D are associated with two distinct phases of thermal pain sensitivity that parallel changes in TRPV1 as determined by paw withdrawal latency (PWL. An early phase of hyperalgesia and a late phase of hypoalgesia are evident. TRPV1-mediated whole cell currents are larger and smaller in dorsal root ganglion (DRG neurons collected from hyperalgesic and hypoalgesic mice. Resiniferatoxin (RTX binding, a measure of TRPV1 expression is increased and decreased in DRG and paw skin of hyperalgesic and hypoalgesic mice, respectively. Immunohistochemical labeling of spinal cord lamina I and II, dorsal root ganglion (DRG, and paw skin from hyperalgesic and hypoalgesic mice reveal increased and decreased TRPV1 expression, respectively. A role for TRPV1 in thermal DPN is further suggested by the failure of STZ treatment to influence thermal nociception in TRPV1 deficient mice. These findings demonstrate that altered TRPV1 expression and function contribute to diabetes-induced changes in thermal perception.

  12. Isoprenoid hydrocarbons produced by thermal alteration of Nostoc muscorum and Rhodopseudomonas spheroides

    Science.gov (United States)

    Philp, R. P.; Brown, S.; Calvin, M.

    1978-01-01

    The potential of algae and photosynthetic bacteria to serve as precursors of kerogen was studied to determine what factors affect the relative rates of formation of precursor hydrocarbons. Cells of Nostoc muscorum and Rhodopseudomonas spheroides were subjected to thermal alteration (by heating samples in glass tubes sealed under nitrogen) for two, four, and twelve weeks. Both unextracted and extracted cells in the absence and presence of montmorillonite were investigated, and the isoprenoid hydrocarbons produced in these experiments were determined. Phytane and five isomeric phytenes were the main hydrocarbons observed; their relative rates of formation in the different experimental conditions are described. No phytadienes, pristane, or pristenes were detected.

  13. Phosphorus availability from the solid fraction of pig slurry is altered by composting or thermal treatment

    DEFF Research Database (Denmark)

    Christel, Wibke; Bruun, Sander; Magid, Jakob

    2014-01-01

    changes in P availability were monitored by repeated DGT application in three amended temperate soils over 16. weeks. P availability was found to decrease in the order: drying. >. composting. >. pyrolysis. >. combustion with increasing degree of processing. Water extractions suggested that no P would......The alteration of easily available phosphorus (P) from the separated solid fraction of pig slurry by composting and thermal processing (pyrolysis or combustion at 300-1000. °C) was investigated by water and acidic extractions and the diffusive gradients in thin films (DGT) technique. Temporal...

  14. Distinguishing solid bitumens formed by thermochemical sulfate reduction and thermal chemical alteration

    Science.gov (United States)

    Kelemen, S.R.; Walters, C.C.; Kwiatek, P.J.; Afeworki, M.; Sansone, M.; Freund, H.; Pottorf, R.J.; Machel, H.G.; Zhang, T.; Ellis, G.S.; Tang, Y.; Peters, K.E.

    2008-01-01

    Insoluble solid bitumens are organic residues that can form by the thermal chemical alteration (TCA) or thermochemical sulfate reduction (TSR) of migrated petroleum. TCA may actually encompass several low temperature processes, such as biodegradation and asphaltene precipitation, followed by thermal alteration. TSR is an abiotic redox reaction where petroleum is oxidized by sulfate. It is difficult to distinguish solid bitumens associated with TCA of petroleum from those associated with TSR when both processes occur at relatively high temperature. The focus of the present work was to characterize solid bitumen samples associated with TCA or TSR using X-ray photoelectron spectroscopy (XPS). XPS is a surface analysis conducted on either isolated or in situ (>25 ??m diameter) solid bitumen that can provide the relative abundance and chemical speciation of carbon, organic and inorganic heteroatoms (NSO). In this study, naturally occurring solid bitumens from three locations, Nisku Fm. Brazeau River area (TSR-related), LaBarge Field Madison Fm. (TSR-related), and the Alaskan Brooks range (TCA-related), are compared to organic solids generated during laboratory simulation of the TSR and TCA processes. The abundance and chemical nature of organic nitrogen and sulfur in solid bitumens can be understood in terms of the nature of (1) petroleum precursor molecules, (2) the concentration of nitrogen by way of thermal stress and (3) the mode of sulfur incorporation. TCA solid bitumens originate from polar materials that are initially rich in sulfur and nitrogen. Aromaticity and nitrogen increase as thermal stress cleaves aliphatic moieties and condensation reactions take place. Organic sulfur in TCA organic solids remains fairly constant with increasing maturation (3.5 to ???17 sulfur per 100 carbons) into aromatic structures and to the low levels of nitrogen in their hydrocarbon precursors. Hence, XPS results provide organic chemical composition information that helps to

  15. Incubation temperature alters thermal preference and response to heat stress of broiler chickens along the rearing phase

    NARCIS (Netherlands)

    Morita, V.S.; Almeida, V.R.; Matos Junior, J.B.; Vicentini, T.I.; Brand, van den H.; Boleli, I.C.

    2016-01-01

    The current study aimed to investigate whether embryonic temperature manipulation may alter thermal preference throughout the rearing phase of broiler chickens and how this manipulation may affect response to thermal challenge, metabolism, growth rate and feed intake rate. Eggs were exposed to a

  16. Hydrothermal alteration at the Roosevelt Hot Springs Thermal Area, Utah. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Parry, W.T.; Bryant, N.L.; Dedolph, R.E.; Ballantyne, J.M.; Ballantyne, G.H.; Rohrs, D.T.; Mason, J.L.

    1978-11-01

    Hot spring deposits in the Roosevelt thermal area consist of opaline sinter, and siliceous-sinter-cemented alluvium. Alluvium, granite to granodiorite plutonic rocks, and amphibolite facies gneiss have been altered by acid-sulfate water to alunite and opal at the surface, and to kaolinite, alunite, montmorillonite, and muscovite to a depth of 60 m. Marcasite and pyrite occur below the water table at about 30m. Deeper alteration sampled to a depth of 2.26 km consists of muscovite, chlorite, calcite, K-feldspar, albite, and epidote with pyrite and sparse chalcopyrite. Thermal water is dilute (ionic strength 0.1 to 0.2) sodium chloride brine. Surface water contains 10 times as much calcium and 100 times as much magnesium as the deep water. Sulfate varies from 48 to 200 mg/l. Present-day spring temperature is 25/sup 0/C but in 1950 the spring temperature was 85/sup 0/C. Computed Na-K-Ca temperature is 241/sup 0/C for the present-day spring, 274/sup 0/C for a well and 283/sup 0/C for the 1957 spring. Quartz saturation temperatures are 170/sup 0/C for the present-day spring, 283/sup 0/C for the well, and 213/sup 0/C for the 1957 spring. A plausible model for development of the near-surface alteration consists of hydrothermal fluid which convectively rises along major fractures. Water cools by conduction and steam separation, and hydrogen ion is produced by oxidation of hydrogen sulfide. The low pH water percolates from the surface downward and reacts with rocks to produce alunite, kaolinite, montmorillonite, and muscovite as hydrogen is consumed.

  17. Diversity of Microfossils and Preservation of Thermally Altered Stromatolites from Anomalous Precambrian Paleoenvironments

    Science.gov (United States)

    Osterhout, Jeffrey Thomas

    Studies of Precambrian life on Earth have been dominated by those of shallow marine deposits, and in order to gain a more complete picture of life's early evolution it is important to consider a wider range of inhabited environments, including deep marine and terrestrial ecosystems. Evidence for early microbial life comes primarily from fossil microorganisms (microfossils), microbial sedimentary structures (e.g., stromatolites), and sedimentary organic matter (e.g., kerogen). The diversity and preservation of these different forms of fossil evidence introduces several challenges to their interpretation, requiring thorough analysis for accurately determining their biological origins. Investigating the paleobiology, organic geochemistry, and thermal maturity of such deposits provides a holistic approach to exploring the Precambrian biosphere in unfamiliar paleoenvironments. This thesis presents two studies of unique Precambrian ecosystems: a diverse microfossil assemblage from a 2.52-billion-year-old (Ga) deep marine deposit, and thermally altered stromatolites from a 1.4-billion-year-old evaporitic lacustrine deposit. Black cherts from the upper Gamohaan Formation (2.52 Ga) contain a consortium of organic-walled large and small coccoids, tubular filaments, and mat-like biofilm structures. Geochemical analyses of stromatolitic chert-carbonate from the Middlebrun Bay Member (1.4 Ga) in contact with a mafic sill show a trend in organic carbon isotopes relative to thermal maturity that is contrary to theoretical predictions. Findings from these studies reveal, for the first time, microfossil evidence of a diverse microbial community in the open Archean ocean prior to the Great Oxidation Event (GOE) 2.4 billion years ago, and provide insight on the relationship between thermal maturity and organic carbon isotopes within a set of terrestrial stromatolites. Together, these studies help capture the enigmatic nature of the Precambrian fossil record and expand our full

  18. Phosphorus availability from the solid fraction of pig slurry is altered by composting or thermal treatment.

    Science.gov (United States)

    Christel, Wibke; Bruun, Sander; Magid, Jakob; Jensen, Lars Stoumann

    2014-10-01

    The alteration of easily available phosphorus (P) from the separated solid fraction of pig slurry by composting and thermal processing (pyrolysis or combustion at 300-1000 °C) was investigated by water and acidic extractions and the diffusive gradients in thin films (DGT) technique. Temporal changes in P availability were monitored by repeated DGT application in three amended temperate soils over 16 weeks. P availability was found to decrease in the order: drying>composting>pyrolysis>combustion with increasing degree of processing. Water extractions suggested that no P would be available after pyrolysis above 700 °C or combustion above 400 °C, respectively, but during soil incubation, even char and ash, processed at 800 °C, increased P availability. Low-temperature pyrolysis vs. combustion was found to favor P availability as did application to acidic vs. neutral soil. Composting and thermal treatment produced a slow-release P fertilizer, with P availability being governed by abiotic and biotic mechanisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Fourier Transform Raman and Statistical Analysis of Thermally Altered Samples of Amber.

    Science.gov (United States)

    Badea, Georgiana I; Caggiani, Maria C; Colomban, Philippe; Mangone, Annarosa; Teodor, Eugenia D; Teodor, Eugen S; Radu, Gabriel L

    2015-12-01

    We report the experimental results that refer to a Fourier transform Raman (FT-Raman) survey of thermally altered Baltic and Romanian amber and the related statistical interpretation of data using principal component analysis (PCA). Although FT-Raman spectra show several small changes in the characteristic features of the investigated amber samples which may be used for discrimination, their visual recognition is relatively difficult, especially when interpreting data from archeological samples, and thus multivariate data analysis may be the solution to more accurately assign the geological origin based on overall characteristic spectral features. The two categories of amber have different behavior in terms of degradation during the experimental alteration, and Romanian amber is more susceptible to physico-chemical transformations by the aggressive environment when compared with Baltic amber. The obtained data were in accordance with the Fourier transform infrared (FT-IR) remarks published previously in a dedicated journal. The Raman technique is an alternative method that requires little to no sample preparation, water does not cause interference, and the spectra can be collected from a small volume (1-50 μm in diameter).

  20. Thermal nociceptive threshold testing detects altered sensory processing in broiler chickens with spontaneous lameness.

    Directory of Open Access Journals (Sweden)

    Becky Hothersall

    Full Text Available Lameness is common in commercially reared broiler chickens but relationships between lameness and pain (and thus bird welfare have proved complex, partly because lameness is often partially confounded with factors such as bodyweight, sex and pathology. Thermal nociceptive threshold (TNT testing explores the neural processing of noxious stimuli, and so can contribute to our understanding of pain. Using an acute model of experimentally induced articular pain, we recently demonstrated that TNT was reduced in lame broiler chickens, and was subsequently attenuated by administration of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs. This study extended these findings to a large sample of commercial broilers. It examined factors affecting thermal threshold (Part 1 and the effect of an NSAID drug (meloxicam, 5 mg/kg and of an opioid (butorphanol; 4 mg/kg (Part 2. Spontaneously lame and matched non-lame birds (n=167 from commercial farms were exposed to ramped thermal stimulations via a probe attached to the lateral aspect of the tarsometatarsus. Baseline skin temperature and temperature at which a behavioural avoidance response occurred (threshold were recorded. In Part 1 bird characteristics influencing threshold were modelled; In Part 2 the effect of subcutaneous administration of meloxicam or butorphanol was investigated. Unexpectedly, after accounting for other influences, lameness increased threshold significantly (Part 1. In Part 2, meloxicam affected threshold differentially: it increased further in lame birds and decreased in non-lame birds. No effect of butorphanol was detected. Baseline skin temperature was also consistently a significant predictor of threshold. Overall, lameness significantly influenced threshold after other bird characteristics were taken into account. This, and a differential effect of meloxicam on lame birds, suggests that nociceptive processing may be altered in lame birds, though mechanisms for this require further

  1. Altered Landscapes and Groundwater Sustainability — Exploring Impacts with Induced Polarization, DC Resistivity, and Thermal Tracing

    Science.gov (United States)

    Eddy-Miller, C.; Caldwell, R.; Wheeler, J.; McCarthy, P.; Binley, A. M.; Constantz, J. E.; Stonestrom, D. A.

    2009-12-01

    Anthropogenically impacted landscapes constitute rising proportions of the Earth’s surface that are characterized by generally elevated nutrient and sediment loadings concurrent with increased consumptive water withdrawals. In recent years a growing number of hydraulically engineered riparian habitat restoration projects have attempted to ameliorate negative impacts of land use on groundwater-surface water systems resulting, e.g., from agricultural practices and urban development. Often the nature of groundwater-surface water interactions in pre- and minimally altered systems is poorly known, making it difficult to assess the impacts of land use and restoration projects on groundwater sustainability. Traditional assessments of surface water parameters (flow, temperature, dissolved oxygen, biotic composition, etc.) can be complemented by hydraulic and thermal measurements to better understand the important role played by groundwater-surface water interactions. Hydraulic and thermal measurements are usually limited to point samples, however, making non-invasive and spatially extensive geophysical characterizations an attractive additional tool. Groundwater-surface water interactions along the Smith River, a tributary to the Missouri River in Montana, and Fish Creek and Flat Creek, tributaries to the Snake River in Wyoming, are being examined using a combination of hydraulic measurements, thermal tracing, and electrical-property imaging. Ninety-two direct-current (DC) resistivity and induced polarization cross sections were obtained at stream transects covering a wide variety of hydrogeologic settings ranging from shallow bedrock to thick alluvial sequences, nature of groundwater-surface water interactions (always gaining, always losing, or seasonally varying) and anthropogenic impacts (minimal low-intensity agriculture to major landscape engineering, including channel reconstruction). DC resistivity and induced polarization delineated mutually distinct features

  2. Sap flow is Underestimated by Thermal Dissipation Sensors due to Alterations of Wood Anatomy

    Science.gov (United States)

    Marañón-Jiménez, S.; Wiedemann, A.; van den Bulcke, J.; Cuntz, M.; Rebmann, C.; Steppe, K.

    2014-12-01

    The thermal dissipation technique (TD) is one of the most commonly adopted methods for sap flow measurements. However, underestimations of up to 60% of the tree transpiration have been reported with this technique, although the causes are not certainly known. The insertion of TD sensors within the stems causes damage of the wood tissue and subsequent healing reactions, changing wood anatomy and likely the sap flow path. However, the anatomical changes in response to the insertion of sap flow sensors and the effects on the measured flow have not been assessed yet. In this study, we investigate the alteration of vessel anatomy on wounds formed around TD sensors. Our main objectives were to elucidate the anatomical causes of sap flow underestimation for ring-porous and diffuse-porous species, and relate these changes to sap flow underestimations. Successive sets of TD probes were installed in early, mid and end of the growing season in Fagus sylvatica (diffuse-porous) and Quercus petraea (ring-porous) trees. They were logged after the growing season and additional sets of sensors were installed in the logged stems with presumably no healing reaction. The wood tissue surrounding each sensor was then excised and analysed by X-ray computed microtomography (X-ray micro CT). This technique allowed the quantification of vessel anatomical characteristics and the reconstruction of the 3-D internal microstructure of the xylem vessels so that extension and shape of the altered area could be determined. Gels and tyloses clogged the conductive vessels around the sensors in both beech and oak. The extension of the affected area was larger for beech although these anatomical changes led to similar sap flow underestimations in both species. The higher vessel size in oak may explain this result and, therefore, larger sap flow underestimation per area of affected conductive tissue. The wound healing reaction likely occurred within the first weeks after sensor installation, which

  3. Alteration, slope-classified alteration, and potential lahar inundation maps of volcanoes for the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Volcano Archive

    Science.gov (United States)

    Mars, John C.; Hubbard, Bernard E.; Pieri, David; Linick, Justin

    2015-01-01

    This study identifies areas prone to lahars from hydrothermally altered volcanic edifices on a global scale, using visible and near infrared (VNIR) and short wavelength infrared (SWIR) reflectance data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and digital elevation data from the ASTER Global Digital Elevation Model (GDEM) dataset. This is the first study to create a global database of hydrothermally altered volcanoes showing quantitatively compiled alteration maps and potentially affected drainages, as well as drainage-specific maps illustrating modeled lahars and their potential inundation zones. We (1) identified and prioritized 720 volcanoes based on population density surrounding the volcanoes using the Smithsonian Institution Global Volcanism Program database (GVP) and LandScan™ digital population dataset; (2) validated ASTER hydrothermal alteration mapping techniques using Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) and ASTER data for Mount Shasta, California, and Pico de Orizaba (Citlaltépetl), Mexico; (3) mapped and slope-classified hydrothermal alteration using ASTER VNIR-SWIR reflectance data on 100 of the most densely populated volcanoes; (4) delineated drainages using ASTER GDEM data that show potential flow paths of possible lahars for the 100 mapped volcanoes; (5) produced potential alteration-related lahar inundation maps using the LAHARZ GIS code for Iztaccíhuatl, Mexico, and Mount Hood and Mount Shasta in the United States that illustrate areas likely to be affected based on DEM-derived volume estimates of hydrothermally altered rocks and the ~2x uncertainty factor inherent within a statistically-based lahar model; and (6) saved all image and vector data for 3D and 2D display in Google Earth™, ArcGIS® and other graphics display programs. In addition, these data are available from the ASTER Volcano Archive (AVA) for distribution (available at http://ava.jpl.nasa.gov/recent_alteration_zones.php).

  4. Melatonin Alters the Mechanical and Thermal Hyperalgesia Induced by Orofacial Pain Model in Rats.

    Science.gov (United States)

    Scarabelot, Vanessa Leal; Medeiros, Liciane Fernandes; de Oliveira, Carla; Adachi, Lauren Naomi Spezia; de Macedo, Isabel Cristina; Cioato, Stefania Giotti; de Freitas, Joice S; de Souza, Andressa; Quevedo, Alexandre; Caumo, Wolnei; Torres, Iraci Lucena da Silva

    2016-10-01

    Melatonin is a neuroendocrine hormone that presents a wide range of physiological functions including regulating circadian rhythms and sleep, enhancing immune function, sleep improvement, and antioxidant effects. In addition, melatonin has received special attention in pain treatment since it is effective and presents few adverse effects. In this study, we evaluated the effect of acute dose of melatonin upon hyperalgesia induced by complete Freund's adjuvant in a chronic orofacial pain model in Sprague-Dawley rats. Nociceptive behavior was assessed by facial Von Frey and the hot plate tests at baseline and thereafter 30, 60, and 120 min, 24 h, and 7 days after melatonin treatment. We demonstrated that acute melatonin administration alters mechanical and thermal hyperalgesia induced by an orofacial pain model (TMD), highlighting that the melatonin effect upon mechanical hyperalgesia remained until 7 days after its administration. Besides, we observed specific tissue profiles of neuroimmunomodulators linked to pain conditions and/or melatonin effect (brain-derived neurotrophic factor, nerve growth factor, and interleukins 6 and 10) in the brainstem levels, and its effects were state-dependent of the baseline of these animals.

  5. Effects of Short-Term Thermal Alteration on Organic Matter in Experimentally-Heated Tagish Lake Observed by Raman Spectroscopy

    Science.gov (United States)

    Chan, Q. H. S.; Nakato, A.; Zolensky, M. E.; Nakamura, T.; Kebukawa, Y.; Maisano, J.; Colbert, M.; Martinez, J. E.

    2017-01-01

    Carbonaceous chondrites exhibit a wide range of aqueous and thermal alteration characteristics, while some are known to demonstrate mineralogical and petrologic evidence of having been thermally metamorphosed after aqueous alteration. This group of meteorites are commonly referred as thermally met-amorphosed carbonaceous chondrites (TMCCs), and their reflectance spectra show resemblances to that of C-type asteroids which typically have low albedos. This suggests that the surfaces of the C-type asteroids are also composed of both hydrous and dehydrated minerals, and thus TMCCs are among the best samples that can be studied in laboratory to reveal the true nature of the C-type asteroids. Although TMCCs are usually meteorites that were previously categorized as CI and CM chondrites, they are not strictly CI/CM because they exhibit isotopic and petrographic characteristics that significantly deviate from typical CI/CM. More appropriately, they are called CI-like and/or CM-like chondrites. Typical examples of TMCCs include the C2-ung/CM2TIV Belgica (B)-7904 and Yamato (Y) 86720. Thermal alteration is virtually complete in these meteorites and thus they are considered typical end-members of TMCCs exhibiting complete dehydration of matrix phyllosilicates. The estimated heating conditions are 10 to 103 days at 700 C to 1 to 100 hours at 890 C, i.e. short-term heating induced by impact and/or solar radiation. While the petrology and chemistry of TMCCs have only recently been extensively characterized, we have just begun to study in detail their organic contents. In order to understand how short-term heating affects the maturity of insoluble organic matter (IOM) in hydrous chondrites, we investigated experimentally-heated Tagish Lake meteorite using Raman spectroscopy, as the chemical and bulk oxygen isotopic compositions of the matrix of the carbonate (CO3)-poor lithology of the Tagish Lake (hereafter Tag) meteorite bears similarities to the TMCCs.

  6. Thermal stress alters expression of genes involved in one carbon and DNA methylation pathways in Atlantic cod embryos.

    Science.gov (United States)

    Skjærven, Kaja H; Hamre, Kristin; Penglase, Samuel; Finn, Roderick Nigel; Olsvik, Pål A

    2014-03-16

    One-carbon (1-C) metabolism is essential for normal embryonic development through its regulation of DNA methylation and cell proliferation. With consideration to the potential future anthropogenic oceanic warming, we studied the effects of both acute thermal stress and continuous thermal stress (10°C) during Atlantic cod embryo development on the expression levels of genes associated with the 1-C metabolism, including DNA methyltransferases. We conducted a phylogenetic analysis of vertebrate DNA methyltransferases to determine the number and similarity of DNMT found in Atlantic cod. This analysis revealed that Atlantic cod have one maintenance dnmt (dnmt1) and five de novo DNMTs (dnmt4, dnmt3, dnmt3b, dnmt3aa, dnmt3ab). Stage specific changes in expression levels occurred for all genes analyzed. The effect of acute thermal stress was evaluated during early development. Compared to controls these experiments showed significant alterations in expression levels of several genes, that in some instances were reversed at later stages of development. A significant effect of continuous thermal stress was found in gastrula embryos where lower mRNA expression levels of 1-C metabolism, de novo DNMTs and cell proliferation genes were detected. One exception was the maintenance DNMT, which was only sensitive to acute and not continuous thermal stress. DNA methylation status indicated that blastula embryos were hypomethylated compared to spermatozoa and late gastrula stages. In post-gastrula stage, however, continuous thermal stress resulted in a higher degree of DNA methylation compared to controls. These data reveal that the regulation of epigenetically important transcripts in the 1-C metabolism of Atlantic cod embryos is sensitive to thermal stress. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. How thermal stress alters the confinement of polymers vitrificated in nanopores

    Science.gov (United States)

    Teng, Chao; Li, Linling; Wang, Yong; Wang, Rong; Chen, Wei; Wang, Xiaoliang; Xue, Gi

    2017-05-01

    Understanding and controlling the glass transition temperature (Tg) and dynamics of polymers in confined geometries are of significance in both academia and industry. Here, we investigate how the thermal stress induced by a mismatch in the coefficient of thermal expansion affects the Tg behavior of polystyrene (PS) nanorods located inside cylindrical alumina nanopores. The size effects and molecular weight dependence of the Tg are also studied. A multi-step relaxation process was employed to study the relationship between thermal stress and cooling rate. At fast cooling rates, the imparted thermal stress would overcome the yield stress of PS and peel chains off the pore walls, while at slow cooling rates, chains are kept in contact with the pore walls due to timely dissipation of the produced thermal stress during vitrification. In smaller nanopores, more PS chains closely contact with pore walls, then stronger internal thermal stress would be generated between core and shell of PS nanorod, which results in a larger deviation between two Tgs. The core part of PS shows lower Tg than bulk value, which can induce faster dynamics in the center region. A complex and important role stress plays is supposed in complex confinement condition, e.g., in nanopores, during vitrification.

  8. Synergistic effects of ultraviolet radiation, thermal cycling and atomic oxygen on altered and coated Kapton surfaces

    Science.gov (United States)

    Dever, Joyce A.; Bruckner, Eric J.; Rodriguez, Elvin

    1992-01-01

    The photovoltaic (PV) power system for Space Station Freedom (SSF) uses solar array blankets which provide structural support for the solar cells and house the electrical interconnections. In the low earth orbital (LEO) environment where SSF will be located, surfaces will be exposed to potentially damaging environmental conditions including solar ultraviolet (UV) radiation, thermal cycling, and atomic oxygen. It is necessary to use ground based tests to determine how these environmental conditions would affect the mass loss and optical properties of candidate SSF blanket materials. Silicone containing, silicone coated, and SiO(x) coated polyimide film materials were exposed to simulated LEO environmental conditions to determine their durability and whether the environmental conditions of UV, thermal cycling and oxygen atoms act synergistically on these materials. A candidate PV blanket material called AOR Kapton, a polysiloxane polyimide cast from a solution mixture, shows an improvement in durability to oxygen atoms erosion after exposure to UV radiation or thermal cycling combined with UV radiation. This may indicate that the environmental conditions react synergistically with this material, and the damage predicted by exposure to atomic oxygen alone is more severe than that which would occur in LEO where atomic oxygen, thermal cycling and UV radiation are present together.

  9. Temporal variability in the thermal regime of the lower Ebro River (Spain) and alteration due to anthropogenic factors

    Science.gov (United States)

    Prats, Jordi; Val, Rafael; Armengol, Joan; Dolz, Josep

    2010-06-01

    SummaryThe Ebro River is one of the longest rivers in Spain and it also has the greatest discharge. Its lower part is highly regulated and includes a system of three reservoirs (Mequinensa, Riba-roja and Flix). The water temperature is altered because of the release of hypolimnetic water and the use of water for cooling at the Ascó nuclear power plant. The thermal regime of the lower Ebro River on different time scales and the changes caused by anthropogenic factors, especially the system of reservoirs and the thermal effluent of the nuclear power plant, have been studied by installing a net of water temperature measuring stations and by using historical water temperature data provided by the thermal power plant at Escatrón. An increase of 2.3 °C in the mean annual water temperature could be demonstrated in the period 1955-2000 at this site. The effects of the system of reservoirs and of the nuclear power plant were the usual for this kind of structures and could be detected many kilometres downstream. In the summer, the cooling effect of the reservoirs and the warming effect of the nuclear power plant compensated each other. In winter, the warming effect of both summed up.

  10. Thermal alteration of terrestrial palynomorphs in mid-Cretaceous organic-rich mudstones intruded by an igneous sill (Newfoundland Margin, ODP Hole 1276A)

    Energy Technology Data Exchange (ETDEWEB)

    Pross, Joerg; Schellenberg, Franziska [Institute of Geosciences, University of Frankfurt, Senckenberganlage 32-34, D-60054 Frankfurt (Germany); Pletsch, Thomas; Kus, Jolanta [Federal Institute for Geosciences and Natural Resources, Stilleweg 2, D-30655 Hannover (Germany); Shillington, Donna J. [School of Earth and Ocean Science, National Oceanography Centre Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH (United Kingdom); Ligouis, Bertrand [Laboratories for Applied Organic Petrology, Sigwartstr. 10, D-72076 Tuebingen (Germany)

    2007-05-01

    Most approaches used to reconstruct thermal alteration of sediments necessitate advanced, relatively expensive analytical techniques. We have evaluated the fidelity of a less costly, relatively simple approach of visually assessing sporomorph colours to determine thermal alteration. The sporomorph-based thermal alteration estimates were compared to vitrinite reflectance data from the same samples. As study material, we selected a succession of mid-Cretaceous (Albian) organic-rich clay- and siltstones intruded by a diabase sill that was recovered from Ocean Drilling Program (ODP) Hole 1276A, off Newfoundland. Six sporomorph groups (SG), each consisting of morphologically well-defined, easily identifiable constituents with long stratigraphic ranges, were individually evaluated for their thermal alteration signals. These groups are: (1) leiotrilete spores of the genera Biretisporites, Cyathidites, Deltoidospora, Dictyophyllidites, Gleicheniidites, and Leiotriletes (SG-1; subdivided into three subgroups SG-1a, SG-1b and SG-1c with sporoderm thicknesses < 1 {mu}m, 1-1.5 {mu}m and > 1.5 {mu}m, respectively); (2) trilete, rugulate spores of the genera Camerozonosporites and Lycopodiacidites (SG-2); (3) trilete, striate spores of the genera Appendicisporites, Cicatricosisporites and Plicatella (SG-3); and (4) the gymnosperm-pollen taxon Classopollis torosus (SG-4). Sporomorph colours were determined using Munsell colour standards under reproducible optical conditions. To minimize the potential influence of reworked specimens on the dataset, only the lightest 50% of all counted specimens per sporomorph group were evaluated for their thermal alteration signals. The thermal alteration estimates from all sporomorph groups yield an internally consistent picture that is compatible with vitrinite reflectance data from the same samples. They indicate that downhole thermal alteration does not increase until 20 m above the igneous sill. A steep rise occurs only at 4.23 m above the

  11. Acute plasma volume expansion alters cardiovascular but not thermal function during moderate intensity prolonged exercise.

    Science.gov (United States)

    Roy, B D; Green, H J; Grant, S M; Tarnopolsky, M A

    2000-03-01

    To investigate the hypothesis that the increase in plasma volume (PV) that typically occurs with training results in improved cardiovascular and thermal regulation during prolonged exercise, eight untrained males (V(O2)peak = 3.52 +/- 0.12 L x min(-1)) performed 90 min of cycle ergometry at 62% V(O2)peak before and after acute PV expansion. Subjects were infused with a PV-expanding solution (dextran (6%) or Pentaspan (10%)) equivalent to 6.7 mL x kg(-1) body mass (PVX) or acted as their own control (CON) in a randomized order. PVX resulted in a calculated 15.8% increase in resting PV, which relative to CON, was maintained throughout the exercise (P performance without affecting the thermoregulatory response to prolonged cycle exercise.

  12. Forest management, litter dynamics and the altered energetic properties of soil organic matter (SOM) - Quantifying anthropogenic change with thermal analysis

    Science.gov (United States)

    Liles, G. C.; Horwath, W. R.

    2012-12-01

    Soils are an open thermodynamic system, far from equilibrium, sustained by primary productivity and the interaction between mineralogy and soil organic matter (SOM). Quantifying the effect of anthropogenic alteration of inputs (litter/roots and fertilizer) on SOM energetic properties is a valuable missing piece of C and energy cycles in all terrestrial ecosystems. Thermal analysis (TA) applied to the study of SOM has received limited attention but provides a thermodynamic framework to quantify mass and energy dynamics in soils and unify the assessment of resource flux, attenuation and use in natural and managed systems across temporal scales. Managed forests are a critical and extensive land-use across the globe and in many cases provide model conditions to develop quantitative linkage between direct anthropogenic 'disturbance' - i.e. treatment - and soil change. Our research investigated the effects of litter and fertilizer inputs on SOM energetic properties in two experimental forest plantations in Northern California. Thermogravimetry-Differential Scanning Calorimetry (TG-DSC) was used to quantify soils across the upper profiles of these two forested Ultisols (0-30 cm) and assess energy density in three primary thermal 'fractions', corresponding to the oxidation of carbohydrates and lipids (150-350 C - Exo-1), aromatic and condensed polymers (400-460 C - Exo-2) and refractory/mineral associated C (500-550 C - Exo-3). We developed model distributions of SOM thermal stability, with replicate soil samples (n=6), representing three depths (0-10, 10-20, & 20-30 cm) that received simple (pine - S) and diverse (pine+shrub - D) litter inputs with and without fertilization (F) to assess if contrasting inputs qualities and mineral properties alter SOM energetics. In surface soils (0-10 cm), SOM energetic properties are consistent across sites and treatments displaying relative thermal symmetry with proportional energy densities (percent of total energy) of Exo-1 ~ 26

  13. The role of minerals in the thermal alteration of organic matter. III - Generation of bitumen in laboratory experiments

    Science.gov (United States)

    Huizinga, Bradley J.; Tannenbaum, Eli; Kaplan, I. R.

    A series of pyrolysis experiments, utilizing two different immature kerogens (from the Monterey and Green River Formations) mixed with common sedimentary minerals (calcite, illite, or Na-montmorillonite), was conducted to study the impact of the mineral matrix on the bitumen that was generated. Calcite has no significant influence on the thermal evolution of bitumen and also shows virtually no adsorption capacity for any of the pyrolysate. In contrast, montmorillonite (M) and illite, to a lesser extent, alter bitumen during dry pyrolysis. M and illite also display strong adsorption capacities for the polar constituents of bitumen. By this process, hydrocarbons are substantially concentrated within the pyrolysate that is not strongly adsorbed on the clay matrices. The effects of the clay minerals are significantly reduced during hydrous pyrolysis. The strong adsorption capacities of M and illite, as well as their thermocatalytic properties, may in part explain why light oils and gases are generated from certain argillaceous source-rock assemblages, whereas heavy immature oils are often derived from carbonate source rocks.

  14. The role of minerals in the thermal alteration of organic matter--III. Generation of bitumen in laboratory experiments.

    Science.gov (United States)

    Huizinga, B J; Tannenbaum, E; Kaplan, I R

    1987-01-01

    A series of pyrolysis experiments, utilizing two different immature kerogens (from the Monterey and Green River Formations) mixed with common sedimentary minerals (calcite, illite, or Na-montmorillonite), was conducted to study the impact of the mineral matrix on the bitumen that was generated. Calcite has no significant influence on the thermal evolution of bitumen and also shows virtually no adsorption capacity for any of the pyrolysate. In contrast, montmorillonite and illite, to a lesser extent, alter bitumen during dry pyrolysis. Montmorillonite and illite also display strong adsorption capacities for the polar constituents of bitumen. By this process, hydrocarbons are substantially concentrated within the pyrolysate that is not strongly adsorbed on the clay matrices. The effects of the clay minerals are significantly reduced during hydrous pyrolysis. The strong adsorption capacities of montmorillonite and illite, as well as their thermocatalytic properties, may in part explain why light oils and gases are generated from certain argillaceous source-rock assemblages, whereas heavy immature oils are often derived from carbonate source rocks.

  15. Hydrothemal Alteration Mapping Using Feature-Oriented Principal Component Selection (fpcs) Method to Aster DATA:WIKKI and Mawulgo Thermal Springs, Yankari Park, Nigeria

    Science.gov (United States)

    Abubakar, A. J.; Hashim, M.; Pour, A. B.

    2017-10-01

    Geothermal systems are essentially associated with hydrothermal alteration mineral assemblages such as iron oxide/hydroxide, clay, sulfate, carbonate and silicate groups. Blind and fossilized geothermal systems are not characterized by obvious surface manifestations like hot springs, geysers and fumaroles, therefore, they could not be easily identifiable using conventional techniques. In this investigation, the applicability of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were evaluated in discriminating hydrothermal alteration minerals associated with geothermal systems as a proxy in identifying subtle Geothermal systems at Yankari Park in northeastern Nigeria. The area is characterized by a number of thermal springs such as Wikki and Mawulgo. Feature-oriented Principal Component selection (FPCS) was applied to ASTER data based on spectral characteristics of hydrothermal alteration minerals for a systematic and selective extraction of the information of interest. Application of FPCS analysis to bands 5, 6 and 8 and bands 1, 2, 3 and 4 datasets of ASTER was used for mapping clay and iron oxide/hydroxide minerals in the zones of Wikki and Mawulgo thermal springs in Yankari Park area. Field survey using GPS and laboratory analysis, including X-ray Diffractometer (XRD) and Analytical Spectral Devices (ASD) were carried out to verify the image processing results. The results indicate that ASTER dataset reliably and complementarily be used for reconnaissance stage of targeting subtle alteration mineral assemblages associated with geothermal systems.

  16. HYDROTHEMAL ALTERATION MAPPING USING FEATURE-ORIENTED PRINCIPAL COMPONENT SELECTION (FPCS METHOD TO ASTER DATA:WIKKI AND MAWULGO THERMAL SPRINGS, YANKARI PARK, NIGERIA

    Directory of Open Access Journals (Sweden)

    A. J. Abubakar

    2017-10-01

    Full Text Available Geothermal systems are essentially associated with hydrothermal alteration mineral assemblages such as iron oxide/hydroxide, clay, sulfate, carbonate and silicate groups. Blind and fossilized geothermal systems are not characterized by obvious surface manifestations like hot springs, geysers and fumaroles, therefore, they could not be easily identifiable using conventional techniques. In this investigation, the applicability of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER were evaluated in discriminating hydrothermal alteration minerals associated with geothermal systems as a proxy in identifying subtle Geothermal systems at Yankari Park in northeastern Nigeria. The area is characterized by a number of thermal springs such as Wikki and Mawulgo. Feature-oriented Principal Component selection (FPCS was applied to ASTER data based on spectral characteristics of hydrothermal alteration minerals for a systematic and selective extraction of the information of interest. Application of FPCS analysis to bands 5, 6 and 8 and bands 1, 2, 3 and 4 datasets of ASTER was used for mapping clay and iron oxide/hydroxide minerals in the zones of Wikki and Mawulgo thermal springs in Yankari Park area. Field survey using GPS and laboratory analysis, including X-ray Diffractometer (XRD and Analytical Spectral Devices (ASD were carried out to verify the image processing results. The results indicate that ASTER dataset reliably and complementarily be used for reconnaissance stage of targeting subtle alteration mineral assemblages associated with geothermal systems.

  17. Hydrothermal alteration maps of the central and southern Basin and Range province of the United States compiled from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data

    Science.gov (United States)

    Mars, John L.

    2013-01-01

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and Interactive Data Language (IDL) logical operator algorithms were used to map hydrothermally altered rocks in the central and southern parts of the Basin and Range province of the United States. The hydrothermally altered rocks mapped in this study include (1) hydrothermal silica-rich rocks (hydrous quartz, chalcedony, opal, and amorphous silica), (2) propylitic rocks (calcite-dolomite and epidote-chlorite mapped as separate mineral groups), (3) argillic rocks (alunite-pyrophyllite-kaolinite), and (4) phyllic rocks (sericite-muscovite). A series of hydrothermal alteration maps, which identify the potential locations of hydrothermal silica-rich, propylitic, argillic, and phyllic rocks on Landsat Thematic Mapper (TM) band 7 orthorectified images, and geographic information systems shape files of hydrothermal alteration units are provided in this study.

  18. Altered Potassium Ion Channel Function as a Possible Mechanism of Increased Blood Pressure in Rats Fed Thermally Oxidized Palm Oil Diets.

    Science.gov (United States)

    Nkanu, Etah E; Owu, Daniel U; Osim, Eme E

    2017-12-27

    Intake of thermally oxidized palm oil leads to cytotoxicity and alteration of the potassium ion channel function. This study investigated the effects of fresh and thermally oxidized palm oil diets on blood pressure and potassium ion channel function in blood pressure regulation. Male Wistar rats were randomly divided into three groups of eight rats. Control group received normal feed; fresh palm oil (FPO) and thermally oxidized palm oil (TPO) groups were fed a diet mixed with 15% (weight/weight) fresh palm oil and five times heated palm oil, respectively, for 16 weeks. Blood pressure was measured; blood samples, hearts, and aortas were collected for biochemical and histological analyses. Thermally oxidized palm oil significantly elevated basal mean arterial pressure (MAP). Glibenclamide (10-5 mmol/L) and tetraethylammonium (TEA; 10-3 mmol/L) significantly raised blood pressure in TPO compared with FPO and control groups. Levcromakalim (10-6 mmol/L) significantly (p palm oil increases MAP probably due to the attenuation of adenosine triphosphate-sensitive potassium (KATP) and large-conductance calcium-dependent potassium (BKCa) channels, tissue peroxidation, and altered histological structures of the heart and blood vessels.

  19. Thermal maturity patterns in the Ordovician and Devonian of Pennsylvania using conodont color alteration index (CAI) and vitrinite reflectance (%Ro)

    Science.gov (United States)

    Repetski, J.E.; Ryder, R.T.; Harper, J.A.; Trippi, M.H.

    2006-01-01

    This new series of maps enhances previous thermal maturity maps in Pennsylvania by establishing: 1) new subsurface CAI data points for the Ordovician and Devonian and 2) new %Ro and Rock Eval subsurface data points for Middle and Upper Devonian black shale units. Thermal maturity values for the Ordovician and Devonian strata are of major interest because they contain the source rocks for most of the oil and natural gas resources in the basin. Thermal maturity patterns of the Middle Ordovician Trenton Group are evaluated here because they closely approximate those of the overlying Ordovician Utica Shale that is believed to be the source rock for the regional oil and gas accumulation in Lower Silurian sandstones and for natural gas fields in fractured dolomite reservoirs of the Ordovician Black River-Trenton Limestones. Improved CAI-based thermal maturity maps of the Ordovician are important to identify areas of optimum gas generation from the Utica Shale and to provide constraints for interpreting the origin of oil and gas in the Lower Silurian regional accumulation and Ordovician Black River-Trenton fields. Thermal maturity maps of the Devonian will better constrain burial history-petroleum generation models of the Utica Shale, as well as place limitations on the origin of regional oil and gas accumulations in Upper Devonian sandstone and Middle to Upper Devonian black shale.

  20. Thermal metamorphism of primitive meteorites. VII - Mineralogy-petrology of heated Murchison /C2/ and alteration of C30 and other chondrites

    Science.gov (United States)

    Matza, S. D.; Lipschutz, M. E.

    1978-01-01

    Alterations caused by week-long heating of Murchison in a low-pressure environment at 400-1400 C are of two types: thermodynamically favored kinetically controlled or thermodynamically controlled rapid processes. Kinetically controlled changes pertinent to chondritic evolution and which vary progressively with temperature in heated Murchison include: chondrule blurring; matrix coarsening; increasing mean Fa and Fs contents of ferromagnesian silicates; equilibration of olivine; increasing Mg/Si, Ca/Si, Al/Si, and Cr/Si and decreasing Fe/Si, Ni/Si, and S/Si in matrix; Cr loss from kamacite; and homogenization and Ni-zoning in taenite at high temperatures. Low-temperature thermodynamically controlled changes include: transformation of high-Ni troilite to low-Ni and formation of Ni- and Co-rich metal from pentlandite. High-temperature changes include formation of Cr-rich magnetite and formation of a Ni-rich sulfide similar to that found in highly altered chondrites. Trends resulting from processes of both kinds in Murchison are consistent with characteristics of a postulated C30 metamorphic suite, while those changes caused by reactions of the second kind are similar to those in heavily shock-heated ordinary chondrites and the heavily metamorphosed C5-6 chondrite, Mulga West. Either the simulations support the metamorphic origin of the C30 suite and other thermally induced changes or the natural alterations support the utility of laboratory simulations in studying meteoritic evolution.

  1. Thermal alteration of organic matter in recent marine sediments. 1: Pigments. [photosynthetic pigments from Tanner Basin off Southern California

    Science.gov (United States)

    Ikan, R.; Aizenshtat, Z.; Baedecker, M. J.; Kaplan, I. R.

    1974-01-01

    Sediment from Tanner Basin, the outer continental shelf off Southern California, was analyzed for photosynthetic pigments and their derivatives, namely carotenes and chlorins. Samples of the sediment were also exposed to raised temperatures (65, 100, 150 C) for various periods of time (1 week, 1 month, 2 months). Analysis of the heat-treated sediment revealed the presence of alpha-ionene and 2,6-dimethylnapthalene, thermal degradation products of Betacarotente. Chlorins were converted to nickel porphyrins of both DPEP and etio series. Possible mechanisms of these transformations are presented.

  2. Thermal post-treatment alters nutrient release from a controlled-release fertilizer coated with a waterborne polymer

    OpenAIRE

    Zhou, Zijun; Du, Changwen; Li, Ting; Shen, Yazhen; Zhou, Jianmin

    2015-01-01

    Controlled-release fertilizers (CRF) use a controlled-release technology to enhance the nutrient use efficiency of crops. Many factors affect the release of nutrients from the waterborne polymer-coated CRF, but the effects of thermal post-treatments remain unclear. In this study, a waterborne polyacrylate-coated CRF was post-treated at different temperatures (30 °C, 60 °C, and 80 °C) and durations (2, 4, 8, 12, and 24 h) after being developed in the Wurster fluidized bed. To characterize the ...

  3. Strong thermal acclimation of photosynthesis in tropical and temperate wet-forest tree species: the importance of altered Rubisco content.

    Science.gov (United States)

    Scafaro, Andrew P; Xiang, Shuang; Long, Benedict M; Bahar, Nur H A; Weerasinghe, Lasantha K; Creek, Danielle; Evans, John R; Reich, Peter B; Atkin, Owen K

    2017-07-01

    Understanding of the extent of acclimation of light-saturated net photosynthesis (An ) to temperature (T), and associated underlying mechanisms, remains limited. This is a key knowledge gap given the importance of thermal acclimation for plant functioning, both under current and future higher temperatures, limiting the accuracy and realism of Earth system model (ESM) predictions. Given this, we analysed and modelled T-dependent changes in photosynthetic capacity in 10 wet-forest tree species: six from temperate forests and four from tropical forests. Temperate and tropical species were each acclimated to three daytime growth temperatures (Tgrowth ): temperate - 15, 20 and 25 °C; tropical - 25, 30 and 35 °C. CO2 response curves of An were used to model maximal rates of RuBP (ribulose-1,5-bisphosphate) carboxylation (Vcmax ) and electron transport (Jmax ) at each treatment's respective Tgrowth and at a common measurement T (25 °C). SDS-PAGE gels were used to determine abundance of the CO2 -fixing enzyme, Rubisco. Leaf chlorophyll, nitrogen (N) and mass per unit leaf area (LMA) were also determined. For all species and Tgrowth , An at current atmospheric CO2 partial pressure was Rubisco-limited. Across all species, LMA decreased with increasing Tgrowth . Similarly, area-based rates of Vcmax at a measurement T of 25 °C (Vcmax25 ) linearly declined with increasing Tgrowth , linked to a concomitant decline in total leaf protein per unit leaf area and Rubisco as a percentage of leaf N. The decline in Rubisco constrained Vcmax and An for leaves developed at higher Tgrowth and resulted in poor predictions of photosynthesis by currently widely used models that do not account for Tgrowth -mediated changes in Rubisco abundance that underpin the thermal acclimation response of photosynthesis in wet-forest tree species. A new model is proposed that accounts for the effect of Tgrowth -mediated declines in Vcmax25 on An , complementing current photosynthetic thermal

  4. The role of minerals in the thermal alteration of organic matter--IV. Generation of n-alkanes, acyclic isoprenoids, and alkenes in laboratory experiments.

    Science.gov (United States)

    Huizinga, B J; Tannenbaum, E; Kaplan, I R

    1987-01-01

    A series of pyrolysis experiments, utilizing two different immature oil-prone kerogens ("type I": Green River Formation kerogen; "Type II": Monterey Formation kerogen) mixed with common sedimentary minerals (calcite, illite, or Na-montmorillonite), was conducted to study the effects of minerals on the generation of n-alkanes, acyclic isoprenoids, and alkenes during laboratory-simulated catagenesis of kerogen. The influence of clay minerals on the aliphatic hydrocarbons is critically dependent on the water concentration during laboratory thermal maturation. Under extremely low contents of water (i.e., dry pyrolysis, where only pyrolysate water is present), C12(+) -range n-alkanes and acyclic isoprenoids are mostly destroyed by montmorillonite but undergo only minor alteration with illite. Both clay minerals significantly reduce alkene formation during dry pyrolysis. Under hydrous conditions (mineral/water = 2:1), the effects of the clay minerals are substantially reduced. In addition, the dry pyrolysis experiments show that illite and montmorillonite preferentially retain large amounts of the polar constituents of bitumen, but not n-alkanes or acyclic isoprenoids. Therefore, bitumen fractionation according to polarity differences occurs in the presence of these clay minerals. By this process, n-alkanes and acyclic isoprenoids are concentrated in the bitumen fraction that is not strongly adsorbed on the clay matrices. The extent of these concentrations effects is greatly diminished during hydrous pyrolysis. In contrast, calcite has no significant influence on the thermal evolution of the hydrocarbons. In addition, calcite is incapable of retaining bitumen. Therefore, the fractionation of n-alkanes or acyclic isoprenoids relative to the polar constituents of bitumen is insignificant in the presence of calcite.

  5. Sharp and blunt force trauma concealment by thermal alteration in homicides: An in-vitro experiment for methodology and protocol development in forensic anthropological analysis of burnt bones.

    Science.gov (United States)

    Macoveciuc, Ioana; Márquez-Grant, Nicholas; Horsfall, Ian; Zioupos, Peter

    2017-06-01

    Burning of human remains is one method used by perpetrators to conceal fatal trauma and expert opinions regarding the degree of skeletal evidence concealment are often disparate. This experiment aimed to reduce this incongruence in forensic anthropological interpretation of burned human remains and implicitly contribute to the development of research methodologies sufficiently robust to withstand forensic scrutiny in the courtroom. We have tested the influence of thermal alteration on pre-existing sharp and blunt trauma on twenty juvenile sheep radii in the laboratory using an automated impact testing system and an electric furnace. The testing conditions simulated a worst-case scenario where remains with pre-existing sharp or blunt trauma were exposed to burning with an intentional vehicular fire scenario in mind. All impact parameters as well as the burning conditions were based on those most commonly encountered in forensic cases and maintained constant throughout the experiment. The results have shown that signatures associated with sharp and blunt force trauma were not masked by heat exposure and highlights the potential for future standardization of fracture analysis in burned bone. Our results further emphasize the recommendation given by other experts on handling, processing and recording burned remains at the crime scene and mortuary. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Altered embryonic development in northern bobwhite quail (Colinus virginianus) induced by pre-incubation oscillatory thermal stresses mimicking global warming predictions.

    Science.gov (United States)

    Reyna, Kelly S; Burggren, Warren W

    2017-01-01

    Global warming is likely to alter reproductive success of ground-nesting birds that lay eggs normally left unattended for days or even weeks before actual parental incubation, especially in already warm climates. The native North American bobwhite quail (Colinus virginianus) is such a species, and pre-incubation quail eggs may experience temperatures ≥45°C. Yet, almost nothing is known about embryonic survival after such high pre-incubation temperatures. Freshly laid bobwhite quail eggs were exposed during a 12 day pre-incubation period to one of five thermal regimes: low oscillating temperatures (25-40°C, mean = 28.9°C), high oscillating temperatures (30-45°C, mean = 33.9°C), low constant temperatures (28.85°C), high constant temperatures (mean = 33.9°C), or commercially employed pre-incubation temperatures (20°C). After treatment, eggs were then incubated at a standard 37.5°C to determine subsequent effects on embryonic development rate, survival, water loss, hatching, and embryonic oxygen consumption. Both quantity of heating degree hours during pre-incubation and specific thermal regime (oscillating vs. non-oscillating) profoundly affected important aspects of embryo survival and indices of development and growth Pre-incubation quail eggs showed a remarkable tolerance to constant high temperatures (up to 45°C), surviving for 4.5±0.3 days of subsequent incubation, but high oscillating pre-incubation temperature increased embryo survival (mean survival 12.2±1.8 days) and led to more rapid development than high constant temperature (maximum 38.5°C), even though both groups experienced the same total heating degree-hours. Oxygen consumption was ~200-300 μl O2.egg.min-1 at hatching in all groups, and was not affected by pre-incubation conditions. Oscillating temperatures, which are the norm for pre-incubation quail eggs in their natural habitat, thus enhanced survival at higher temperatures. However, a 5°C increase in pre-incubation temperature

  7. Altered embryonic development in northern bobwhite quail (Colinus virginianus induced by pre-incubation oscillatory thermal stresses mimicking global warming predictions.

    Directory of Open Access Journals (Sweden)

    Kelly S Reyna

    Full Text Available Global warming is likely to alter reproductive success of ground-nesting birds that lay eggs normally left unattended for days or even weeks before actual parental incubation, especially in already warm climates. The native North American bobwhite quail (Colinus virginianus is such a species, and pre-incubation quail eggs may experience temperatures ≥45°C. Yet, almost nothing is known about embryonic survival after such high pre-incubation temperatures. Freshly laid bobwhite quail eggs were exposed during a 12 day pre-incubation period to one of five thermal regimes: low oscillating temperatures (25-40°C, mean = 28.9°C, high oscillating temperatures (30-45°C, mean = 33.9°C, low constant temperatures (28.85°C, high constant temperatures (mean = 33.9°C, or commercially employed pre-incubation temperatures (20°C. After treatment, eggs were then incubated at a standard 37.5°C to determine subsequent effects on embryonic development rate, survival, water loss, hatching, and embryonic oxygen consumption. Both quantity of heating degree hours during pre-incubation and specific thermal regime (oscillating vs. non-oscillating profoundly affected important aspects of embryo survival and indices of development and growth Pre-incubation quail eggs showed a remarkable tolerance to constant high temperatures (up to 45°C, surviving for 4.5±0.3 days of subsequent incubation, but high oscillating pre-incubation temperature increased embryo survival (mean survival 12.2±1.8 days and led to more rapid development than high constant temperature (maximum 38.5°C, even though both groups experienced the same total heating degree-hours. Oxygen consumption was ~200-300 μl O2.egg.min-1 at hatching in all groups, and was not affected by pre-incubation conditions. Oscillating temperatures, which are the norm for pre-incubation quail eggs in their natural habitat, thus enhanced survival at higher temperatures. However, a 5°C increase in pre

  8. Thermal alteration of soil organic matter properties: a systematic study to infer response of Sierra Nevada climosequence soils to forest fires

    Science.gov (United States)

    Araya, Samuel N.; Fogel, Marilyn L.; Asefaw Berhe, Asmeret

    2017-02-01

    Fire is a major driver of soil organic matter (SOM) dynamics, and contemporary global climate change is changing global fire regimes. We conducted laboratory heating experiments on soils from five locations across the western Sierra Nevada climosequence to investigate thermal alteration of SOM properties and determine temperature thresholds for major shifts in SOM properties. Topsoils (0 to 5 cm depth) were exposed to a range of temperatures that are expected during prescribed and wild fires (150, 250, 350, 450, 550, and 650 °C). With increase in temperature, we found that the concentrations of carbon (C) and nitrogen (N) decreased in a similar pattern among all five soils that varied considerably in their original SOM concentrations and mineralogies. Soils were separated into discrete size classes by dry sieving. The C and N concentrations in the larger aggregate size fractions (2-0.25 mm) decreased with an increase in temperature, so that at 450 °C the remaining C and N were almost entirely associated with the smaller aggregate size fractions ( < 0.25 mm). We observed a general trend of 13C enrichment with temperature increase. There was also 15N enrichment with temperature increase, followed by 15N depletion when temperature increased beyond 350 °C. For all the measured variables, the largest physical, chemical, elemental, and isotopic changes occurred at the mid-intensity fire temperatures, i.e., 350 and 450 °C. The magnitude of the observed changes in SOM composition and distribution in three aggregate size classes, as well as the temperature thresholds for critical changes in physical and chemical properties of soils (such as specific surface area, pH, cation exchange capacity), suggest that transformation and loss of SOM are the principal responses in heated soils. Findings from this systematic investigation of soil and SOM response to heating are critical for predicting how soils are likely to be affected by future climate and fire regimes.

  9. Hydrothermal Alteration Maps of the Central and Southern Basin and Range Province of the United States Compiled From Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and Interactive Data Language (IDL) logical operator algorithms were used to map...

  10. Detection and mapping of volcanic rock assemblages and associated hydrothermal alteration with Thermal Infrared Multiband Scanner (TIMS) data Comstock Lode Mining District, Virginia City, Nevada

    Science.gov (United States)

    Taranik, James V.; Hutsinpiller, Amy; Borengasser, Marcus

    1986-01-01

    Thermal Infrared Multispectral Scanner (TIMS) data were acquired over the Virginia City area on September 12, 1984. The data were acquired at approximately 1130 hours local time (1723 IRIG). The TIMS data were analyzed using both photointerpretation and digital processing techniques. Karhuen-Loeve transformations were utilized to display variations in radiant spectral emittance. The TIMS image data were compared with color infrared metric camera photography, LANDSAT Thematic Mapper (TM) data, and key areas were photographed in the field.

  11. Macro- and microclimate conditions may alter grapevine deacclimation: variation in thermal amplitude in two contrasting wine regions from North and South America

    Science.gov (United States)

    Antivilo, Francisco Gonzalez; Paz, Rosalía Cristina; Keller, Markus; Borgo, Roberto; Tognetti, Jorge; Juñent, Fidel Roig

    2017-12-01

    Low temperature is a limiting factor that affects vineyard distribution globally. The level of cold hardiness acquired during the dormant season by Vitis sp. is crucial for winter survival. Most research published on this topic has been generated beyond 40° N latitude, where daily mean temperatures may attain injurious levels during the dormant season resulting in significant damage to vines and buds. Symptoms of cold injury have been identified in Mendoza (32-35° S latitude), a Southern Hemisphere wine region characterized by a high thermal amplitude, and warm winds during the dormant season. These symptoms have usually been attributed to drought and/or pathogens, but not to rapid deacclimation followed by injurious low temperatures. Because local information on meteorological events as probable causes is scarce, this research was designed to test and study this assumption by comparing macro-, meso-, and microclimatic data from Mendoza, Argentina, and eastern Washington, USA. The goal was to unveil why freezing damage has occurred in both regions, despite the existence of large climatic differences. Because environmental parameters under field conditions may not correspond to data recorded by conventional weather stations, sensors were installed in vineyards for comparison. Microclimatic conditions on grapevines were also evaluated to assess the most vulnerable portions of field-grown grapevines. In order to better understand if it may be possible to modify cold hardiness status in a short period with high thermal amplitude conditions, deacclimation was induced using a thermal treatment. Hence, despite the fact that Mendoza is warmer, and temperatures are not as extreme as in Washington, high daily thermal amplitude might be partially involved in plant deacclimation, leading to a differential cold hardiness response.

  12. Macro- and microclimate conditions may alter grapevine deacclimation: variation in thermal amplitude in two contrasting wine regions from North and South America

    Science.gov (United States)

    Antivilo, Francisco Gonzalez; Paz, Rosalía Cristina; Keller, Markus; Borgo, Roberto; Tognetti, Jorge; Juñent, Fidel Roig

    2017-07-01

    Low temperature is a limiting factor that affects vineyard distribution globally. The level of cold hardiness acquired during the dormant season by Vitis sp. is crucial for winter survival. Most research published on this topic has been generated beyond 40° N latitude, where daily mean temperatures may attain injurious levels during the dormant season resulting in significant damage to vines and buds. Symptoms of cold injury have been identified in Mendoza (32-35° S latitude), a Southern Hemisphere wine region characterized by a high thermal amplitude, and warm winds during the dormant season. These symptoms have usually been attributed to drought and/or pathogens, but not to rapid deacclimation followed by injurious low temperatures. Because local information on meteorological events as probable causes is scarce, this research was designed to test and study this assumption by comparing macro-, meso-, and microclimatic data from Mendoza, Argentina, and eastern Washington, USA. The goal was to unveil why freezing damage has occurred in both regions, despite the existence of large climatic differences. Because environmental parameters under field conditions may not correspond to data recorded by conventional weather stations, sensors were installed in vineyards for comparison. Microclimatic conditions on grapevines were also evaluated to assess the most vulnerable portions of field-grown grapevines. In order to better understand if it may be possible to modify cold hardiness status in a short period with high thermal amplitude conditions, deacclimation was induced using a thermal treatment. Hence, despite the fact that Mendoza is warmer, and temperatures are not as extreme as in Washington, high daily thermal amplitude might be partially involved in plant deacclimation, leading to a differential cold hardiness response.

  13. 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.

  14. Thermal Processing Alters the Chemical Quality and Sensory Characteristics of Sweetsop (Annona squamosa L.) and Soursop (Annona muricata L.) Pulp and Nectar.

    Science.gov (United States)

    Baskaran, Revathy; Ravi, Ramasamy; Rajarathnam, Somasundaram

    2016-01-01

    The objective of this study was to investigate the effect of thermal processing on the chemical quality and sensory characteristics of Annona squamosa L. and Annona muricata L. fruit pulps and nectar. The fruit pulps were pasteurized at 85 °C for 20 min and nectar prepared as per Food Safety and Standards Authority of India (FSSAI) specifications. The chemical composition of fresh and heated pulps of A. squamosa and A. muricata showed that compared to fresh, the chemical profile and sensory profile changed in heated samples and nectar. The free and bound phenolics of A. squamosa increased in heated pulp (127.61 to 217.22 mg/100 g and 150.34 to 239.74 mg/100 g, respectively), while in A. muricata, free phenolics increased very marginally from 31.73 to 33.74 mg/100 g and bound phenolics decreased from 111.11 to 86.91 mg/100 g. This increase in phenolic content may be attributed to the perception of bitterness and astringency in A. squamosa pulp on heating. In electronic tongue studies, principal component analysis (PCA) confirmed that the fresh and heated pulps had different scores, as indicated by sensory analysis using qualitative descriptive analysis (QDA). E-tongue analysis of samples discriminated the volatile compounds released from the heated A. squamosa and A. muricata fruit pulps and nectar in their respective PCA plots by forming different clusters. © 2015 Institute of Food Technologists®

  15. The Halite-Bearing Zag and Monahans (1998) Meteorite Breccias: Shock Metamorphism, Thermal Metamorphism and Aqueous Alteration on the H-Chondrite Parent Body

    Science.gov (United States)

    Rubin, Alan E.; Zolensky, Michael E.; Bodnar, Robert J.

    2002-01-01

    Zag and Monahans (1998) are H-chondrite regolith breccias comprised mainly of lightcolored metamorphosed clasts, dark clasts that exhibit extensive silicate darkening, and a halite-bearing clastic matrix. These meteorites reflect a complex set of modification processes that occurred on the H-chondrite parent body. The light-colored clasts are thermally metamorphosed H5 and H6 rocks that were fragmented and deposited in the regolith. The dark clasts formed from light-colored clasts during shock events that melted and mobilized a significant fraction of their metallic Fe-Ni and troilite grains. The clastic matrices of these meteorites are rich in solar-wind gases. Parent-body water was required to cause leaching of chondri tic minerals and chondrule glass; the fluids became enriched in Na, K, CI, Br, AI, Ca, Mg and Fe. Evaporation of the fluids caused them to become brines as halides and alkalies became supersaturated; grains of halite (and, in the case of Monahans (1998), halite with sylvite inclusions) precipitated at low temperatures (less than or equal to 100 C) in the porous regolith. In both meteorites fluid inclusions were trapped inside the halite crystals. Primary fluid inclusions were trapped in the growing crystals; secondary inclusions formed subsequently from fluid trapped within healed fractures.

  16. Non-thermal atmospheric pressure plasma inhibits thyroid papillary cancer cell invasion via cytoskeletal modulation, altered MMP-2/-9/uPA activity.

    Directory of Open Access Journals (Sweden)

    Jae Won Chang

    Full Text Available Plasma, the fourth state of matter, is defined as a partially or completely ionized gas that includes a mixture of electrons and ions. Advances in plasma physics have made it possible to use non-thermal atmospheric pressure plasma (NTP in cancer research. However, previous studies have focused mainly on apoptotic cancer cell death mediated by NTP as a potential cancer therapy. In this study, we investigated the effect of NTP on invasion or metastasis, as well as the mechanism by which plasma induces anti-migration and anti-invasion properties in human thyroid papillary cancer cell lines (BHP10-3 and TPC1. Wound healing, pull-down, and Transwell assays demonstrated that NTP reduced cell migration and invasion. In addition, NTP induced morphological changes and cytoskeletal rearrangements, as detected by scanning electron microscopy and immunocytochemistry. We also examined matrix metalloproteinase (MMP-2/-9 and urokinase-type plasminogen activator (uPA activity using gelatin zymography, uPA assays and RT-PCR. FAK, Src, and paxillin expression was detected using Western blot analyses and immunocytochemistry. NTP decreased FAK, Src, and paxillin expression as well as MMP/uPA activity. In conclusion, NTP inhibited the invasion and metastasis of BHP10-3 and TPC1 cells by decreasing MMP-2/-9 and uPA activities and rearranging the cytoskeleton, which is regulated by the FAK/Src complex. These findings suggest novel actions for NTP and may aid in the development of new therapeutic strategies for locally invasive and metastatic cancers.

  17. Alterations in Intestinal Permeability After Thermal Injury,

    Science.gov (United States)

    1992-01-01

    Permeability After Burns-LeVoyer et al R wthe Arrihtv.of Su~gy8 4• u’y 1992, Voue 127 Copright 1992. Akn • Med/kaf Awoctahbn Patlenbs Controls 4. (n-=1...may have a role in the tinal tract is enteral nutrition . I was wondering if by any chance development of increased permeability, then we can evaluate

  18. Thermal Nanosystems and Nanomaterials

    CERN Document Server

    Volz, Sebastian

    2009-01-01

    Heat transfer laws for conduction, radiation and convection change when the dimensions of the systems in question shrink. The altered behaviours can be used efficiently in energy conversion, respectively bio- and high-performance materials to control microelectronic devices. To understand and model those thermal mechanisms, specific metrologies have to be established. This book provides an overview of actual devices and materials involving micro-nanoscale heat transfer mechanisms. These are clearly explained and exemplified by a large spectrum of relevant physical models, while the most advanced nanoscale thermal metrologies are presented.

  19. 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...

  20. Thermal Responsive Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Pasold, Anke

    2015-01-01

    alterations, their respective durability and copper’s architectural (visual and transformative) aesthetic qualities. Through the use of an evolutionary solver, the composite structure of the elements are organised to find the bending behaviour specified by and for the thermal environments. The entire model......The paper presents an architectural computational method and model, which, through additive and subtractive processes, create composite elements with bending behaviour based on thermal variations in the surrounding climatic environment. The present effort is focused on the manipulation of assembly...... composite layers and their relative layer lengths thereby embedding the merged material effect to create a responsive behavioural architectural envelope. Copper and polypropylene are used as base materials for the composite structure due to their high differences in thermal expansion, surface emissivity...

  1. Thermally induced nonlinear mode coupling in high power fiber amplifiers

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Hansen, Kristian Rymann; Alkeskjold, Thomas T.

    2013-01-01

    Thermally induced nonlinear mode coupling leads to transverse mode instability (TMI) in high power fiber amplifiers. A numerical model including altering mode profiles from thermal effects and waveguide perturbations predicts a TMI threshold of ~200W.......Thermally induced nonlinear mode coupling leads to transverse mode instability (TMI) in high power fiber amplifiers. A numerical model including altering mode profiles from thermal effects and waveguide perturbations predicts a TMI threshold of ~200W....

  2. Regional mapping of hydrothermally altered igneous rocks along the Urumieh-Dokhtar, Chagai, and Alborz Belts of western Asia using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and Interactive Data Language (IDL) logical operators: a tool for porphyry copper exploration and assessment: Chapter O in Global mineral resource assessment

    Science.gov (United States)

    Mars, John L.; Zientek, M.L.; Hammarstrom, J.M.; Johnson, K.M.; Pierce, F.W.

    2014-01-01

    Regional maps of phyllic and argillic hydrothermal alteration were compiled using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and logical operator algorithms. The area mapped extends from northwestern Iran to southeastern Pakistan and includes volcanic and magmatic arcs that make up the Urumieh-Dokhtar volcanic belt (UDVB), the Chagai volcanic belt (CVB), and the central part of the Alborz magmatic belt (AMB). The volcanic belts span the Zagros-Makran transform zone and the present day Baluchistan (Makran) volcanic arc. ASTER visible near infrared (VNIR) data contain three bands between 0.52 and 0.86 micrometers (μm) and the short-wave infrared (SWIR) data consist of six bands spanning 1.6 to 2.43 μm with 15-meter (m), and 30-m resolution, respectively.

  3. HYDROGEOLOGY OF THE THERMAL LANDSLIDE

    Energy Technology Data Exchange (ETDEWEB)

    Vantine, J.

    1985-01-22

    The large Thermal Landslide overlies the initial area of geothermal development at The Geysers. The landslide is waterbearing while the underlying Franciscan formation bedrock units are essentially non-waterbearing except where affected by hydrothermal alteration. Perched ground water moving through the landslide is heated prior to discharge as spring flow.

  4. Natural selection on thermal preference, critical thermal maxima and locomotor performance.

    Science.gov (United States)

    Gilbert, Anthony L; Miles, Donald B

    2017-08-16

    Climate change is resulting in a radical transformation of the thermal quality of habitats across the globe. Whereas species have altered their distributions to cope with changing environments, the evidence for adaptation in response to rising temperatures is limited. However, to determine the potential of adaptation in response to thermal variation, we need estimates of the magnitude and direction of natural selection on traits that are assumed to increase persistence in warmer environments. Most inferences regarding physiological adaptation are based on interspecific analyses, and those of selection on thermal traits are scarce. Here, we estimate natural selection on major thermal traits used to assess the vulnerability of ectothermic organisms to altered thermal niches. We detected significant directional selection favouring lizards with higher thermal preferences and faster sprint performance at their optimal temperature. Our analyses also revealed correlational selection between thermal preference and critical thermal maxima, where individuals that preferred warmer body temperatures with cooler critical thermal maxima were favoured by selection. Recent published estimates of heritability for thermal traits suggest that, in concert with the strong selective pressures we demonstrate here, evolutionary adaptation may promote long-term persistence of ectotherms in altered thermal environments. © 2017 The Author(s).

  5. 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...... under specific conditions. At operation level, only few variables are taken into account with unpredictable effects on the assessment of comfort indices. In this paper, the main criteria for the design and assessment of thermal comfort are discussed in order to help building and HVAC systems designers...... 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...

  6. Thermal defoliation

    Science.gov (United States)

    The negative perception some consumers hold regarding agricultural chemicals has resulted in an increased demand for organic foods and fibers, and in increasing political pressure for the regulation of agricultural production practices. This has revived interest in thermal defoliation of cotton and ...

  7. Holographic thermalization

    NARCIS (Netherlands)

    Balasubramanian, V.; Bernamonti, A.; de Boer, J.; Copland, N.; Craps, B.; Keski-Vakkuri, E.; Müller, B.; Schäfer, A.; Shigemori, M.; Staessens, W.

    2011-01-01

    Using the AdS/CFT correspondence, we probe the scale-dependence of thermalization in strongly coupled field theories following a quench, via calculations of two-point functions, Wilson loops and entanglement entropy in d=2,3,4. In the saddlepoint approximation these probes are computed in AdS space

  8. Thermal Hardware for the Thermal Analyst

    Science.gov (United States)

    Steinfeld, David

    2015-01-01

    The presentation will be given at the 26th Annual Thermal Fluids Analysis Workshop (TFAWS 2015) hosted by the Goddard Space Flight Center (GSFC) Thermal Engineering Branch (Code 545). NCTS 21070-1. Most Thermal analysts do not have a good background into the hardware which thermally controls the spacecraft they design. SINDA and Thermal Desktop models are nice, but knowing how this applies to the actual thermal hardware (heaters, thermostats, thermistors, MLI blanketing, optical coatings, etc...) is just as important. The course will delve into the thermal hardware and their application techniques on actual spacecraft. Knowledge of how thermal hardware is used and applied will make a thermal analyst a better engineer.

  9. Thermal Clothing

    Science.gov (United States)

    1997-01-01

    Gateway Technologies, Inc. is marketing and developing textile insulation technology originally developed by Triangle Research and Development Corporation. The enhanced thermal insulation stems from Small Business Innovation Research contracts from NASA's Johnson Space Center and the U.S. Air Force. The effectiveness of the insulation comes from the microencapsulated phase-change materials originally made to keep astronauts gloved hands warm. The applications for the product range from outer wear, housing insulation, and blankets to protective firefighting gear and scuba diving suits. Gateway has developed and begun marketing thermal regulating products under the trademark, OUTLAST. Products made from OUTLAST are already on the market, including boot and shoe liners, winter headgear, hats and caps for hunting and other outdoor sports, and a variety of men's and women's ski gloves.

  10. Turbulent Thermalization

    CERN Document Server

    Micha, Raphael; Micha, Raphael; Tkachev, Igor I.

    2004-01-01

    We study, analytically and with lattice simulations, the decay of coherent field oscillations and the subsequent thermalization of the resulting stochastic classical wave-field. The problem of reheating of the Universe after inflation constitutes our prime motivation and application of the results. We identify three different stages of these processes. During the initial stage of ``parametric resonance'', only a small fraction of the initial inflaton energy is transferred to fluctuations in the physically relevant case of sufficiently large couplings. A major fraction is transfered in the prompt regime of driven turbulence. The subsequent long stage of thermalization classifies as free turbulence. During the turbulent stages, the evolution of particle distribution functions is self-similar. We show that wave kinetic theory successfully describes the late stages of our lattice calculation. Our analytical results are general and give estimates of reheating time and temperature in terms of coupling constants and...

  11. Thermal Infrared Emission Spectroscopy of Synthetic Allophane and Its Potential Formation on Mars

    Science.gov (United States)

    Rampe, E. B.; Kraft, M. D.; Sharp, T. G.; Golden, D. C.; Ming, D. W.

    2010-03-01

    We synthesized allophane, a terrestrial aqueous alteration product, and measured a thermal IR emission spectrum for the public spectral library. The use of this spectrum in martian spectral models can help constrain chemical alteration environments.

  12. Thermal insulator

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, R.; Asada, Y.; Matsuo, Y.; Mikoda, M.

    1985-07-16

    A thermal insulator comprises an expanded resin body having embedded therein an evacuated powder insulation portion which consists of fine powder and a container of film-like plastics or a film-like composite of plastics and metal for enclosing the powder. The resin body has been expanded by a Freon gas as a blowing agent. Since a Freon gas has a larger molecular diameter than the constituent gases of air, it is less likely to permeate through the container than air. Thus present invention provides a novel composite insulator which fully utilizes the benefits of vacuum insulation without necessitating a strong and costly material for a vacuum container.

  13. 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.

  14. Music and Alterity Processes

    Directory of Open Access Journals (Sweden)

    Josep Martí

    2014-10-01

    Full Text Available The concept of alterity constitutes an important issue in anthropological research and, therefore, in the study of musical practices, as well. Without it, we could hardly understand other kinds of music situated in different spaces and time from the observer. In order to effectively approach these musical practices, we have to develop strategies to help us reduce as much as possible that which distorts the vision of the other. However, beyond the strictly epistemological and methodological issues, the study of music cannot ignore the ethical question related to the manner in which Western thought has understood and treated the other: through a hierarchical and stereotypical type of thinking based on the condition of otherness. Throughout the article, different alterity procedures are presented and discussed, such as synecdochization, exoticization, undervaluation, overvaluation, misunderstanding and exclusion. Taking these different alterity strategies into account may help us to better understand how the musical other is constructed, used and ultimately instrumentalized.

  15. How Misinformation Alters Memories.

    Science.gov (United States)

    Wright, Daniel B.; Loftus, Elizabeth F.

    1998-01-01

    Notes that a multitude of studies have demonstrated that misleading postevent information affects people's memories. Contents that the fuzzy-trace theory is a positive step toward understanding the malleability of memory. Discusses fuzzy-trace theory in terms of three primary areas of study: altered response format, maximized misinformation…

  16. Genetic alterations in Glioma

    NARCIS (Netherlands)

    L.B.C. Bralten (Linda); P.J. French (Pim)

    2011-01-01

    textabstractGliomas are the most common type of primary brain tumor and have a dismal prognosis. Understanding the genetic alterations that drive glioma formation and progression may help improve patient prognosis by identification of novel treatment targets. Recently, two major studies have

  17. Seasonal thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

    1984-05-01

    This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

  18. Fundamentals of Thermal Expansion and Thermal Contraction

    OpenAIRE

    Liu, Zi-Kui; Shang, Shun-Li; Wang, Yi

    2017-01-01

    Thermal expansion is an important property of substances. Its theoretical prediction has been challenging, particularly in cases the volume decreases with temperature, i.e., thermal contraction or negative thermal expansion at high temperatures. In this paper, a new theory recently developed by the authors has been reviewed and further examined in the framework of fundamental thermodynamics and statistical mechanics. Its applications to cerium with colossal thermal expansion and Fe3Pt with th...

  19. Immunization alters body odor.

    Science.gov (United States)

    Kimball, Bruce A; Opiekun, Maryanne; Yamazaki, Kunio; Beauchamp, Gary K

    2014-04-10

    Infections have been shown to alter body odor. Because immune activation accompanies both infection and immunization, we tested the hypothesis that classical immunization might similarly result in the alteration of body odors detectable by trained biosensor mice. Using a Y-maze, we trained biosensor mice to distinguish between urine odors from rabies-vaccinated (RV) and unvaccinated control mice. RV-trained mice generalized this training to mice immunized with the equine West Nile virus (WNV) vaccine compared with urine of corresponding controls. These results suggest that there are similarities between body odors of mice immunized with these two vaccines. This conclusion was reinforced when mice could not be trained to directly discriminate between urine odors of RV- versus WNV-treated mice. Next, we trained biosensor mice to discriminate the urine odors of mice treated with lipopolysaccharide (LPS; a general elicitor of innate immunological responses) from the urine of control mice. These LPS-trained biosensors could distinguish between the odors of LPS-treated mouse urine and RV-treated mouse urine. Finally, biosensor mice trained to distinguish between the odors of RV-treated mouse urine and control mouse urine did not generalize this training to discriminate between the odors of LPS-treated mouse urine and control mouse urine. From these experiments, we conclude that: (1) immunization alters urine odor in similar ways for RV and WNV immunizations; and (2) immune activation with LPS also alters urine odor but in ways different from those of RV and WNV. Published by Elsevier Inc.

  20. 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

  1. Monitoring and thermal management.

    Science.gov (United States)

    Lenhardt, Rainer

    2003-12-01

    Anaesthesia alters normal thermoregulatory control of the body, usually leading to perioperative hypothermia. Hypothermia is associated with a large number of serious complications. To assess perianaesthetic hypothermia, core temperature should be monitored vigorously. Pulmonary artery, tympanic membrane, distal oesophageal or nasopharyngeal temperatures reflect core temperature reliably. Core temperatures can be often estimated with reasonable accuracy using oral, axillary and bladder temperatures, except during extreme thermal perturbations. The body site for measurements should be chosen according to the surgical procedure. Unless hypothermia is specifically indicated, efforts should be made to maintain intraoperative core temperatures above 36 degrees C. Forced air is the most effective, commonly available, non-invasive warming method. Resistive heating electrical blankets and circulating water garment systems are an equally effective alternative. Intravenous fluid warming is also helpful when large volumes are required. In some patients, induction of mild therapeutic hypothermia may become an issue for the future. Recent studies indicate that patients suffering from neurological disease may profit from rapid core cooling.

  2. Dynamic thermal environment and thermal comfort.

    Science.gov (United States)

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

    2016-02-01

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

  3. Voltage tunability of thermal conductivity in ferroelectric materials

    Science.gov (United States)

    Ihlefeld, Jon; Hopkins, Patrick Edward

    2016-02-09

    A method to control thermal energy transport uses mobile coherent interfaces in nanoscale ferroelectric films to scatter phonons. The thermal conductivity can be actively tuned, simply by applying an electrical potential across the ferroelectric material and thereby altering the density of these coherent boundaries to directly impact thermal transport at room temperature and above. The invention eliminates the necessity of using moving components or poor efficiency methods to control heat transfer, enabling a means of thermal energy control at the micro- and nano-scales.

  4. Altered fingerprints: analysis and detection.

    Science.gov (United States)

    Yoon, Soweon; Feng, Jianjiang; Jain, Anil K

    2012-03-01

    The widespread deployment of Automated Fingerprint Identification Systems (AFIS) in law enforcement and border control applications has heightened the need for ensuring that these systems are not compromised. While several issues related to fingerprint system security have been investigated, including the use of fake fingerprints for masquerading identity, the problem of fingerprint alteration or obfuscation has received very little attention. Fingerprint obfuscation refers to the deliberate alteration of the fingerprint pattern by an individual for the purpose of masking his identity. Several cases of fingerprint obfuscation have been reported in the press. Fingerprint image quality assessment software (e.g., NFIQ) cannot always detect altered fingerprints since the implicit image quality due to alteration may not change significantly. The main contributions of this paper are: 1) compiling case studies of incidents where individuals were found to have altered their fingerprints for circumventing AFIS, 2) investigating the impact of fingerprint alteration on the accuracy of a commercial fingerprint matcher, 3) classifying the alterations into three major categories and suggesting possible countermeasures, 4) developing a technique to automatically detect altered fingerprints based on analyzing orientation field and minutiae distribution, and 5) evaluating the proposed technique and the NFIQ algorithm on a large database of altered fingerprints provided by a law enforcement agency. Experimental results show the feasibility of the proposed approach in detecting altered fingerprints and highlight the need to further pursue this problem.

  5. Solar Thermal Energy Technology

    Energy Technology Data Exchange (ETDEWEB)

    Cason, D.L.; Pitsenbarger, J. [eds.

    1996-02-01

    Solar Thermal Energy Technology (PST) announces on a bimonthly basis the current worldwide research and development information that would expand the technology base required for the advancement of solar thermal systems as a significant energy resource.

  6. Ouellette Thermal Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Thermal Test Facility is a joint Army/Navy state-of-the-art facility (8,100 ft2) that was designed to:Evaluate and characterize the effect of flame and thermal...

  7. Music alters visual perception.

    Science.gov (United States)

    Jolij, Jacob; Meurs, Maaike

    2011-04-21

    Visual perception is not a passive process: in order to efficiently process visual input, the brain actively uses previous knowledge (e.g., memory) and expectations about what the world should look like. However, perception is not only influenced by previous knowledge. Especially the perception of emotional stimuli is influenced by the emotional state of the observer. In other words, how we perceive the world does not only depend on what we know of the world, but also by how we feel. In this study, we further investigated the relation between mood and perception. We let observers do a difficult stimulus detection task, in which they had to detect schematic happy and sad faces embedded in noise. Mood was manipulated by means of music. We found that observers were more accurate in detecting faces congruent with their mood, corroborating earlier research. However, in trials in which no actual face was presented, observers made a significant number of false alarms. The content of these false alarms, or illusory percepts, was strongly influenced by the observers' mood. As illusory percepts are believed to reflect the content of internal representations that are employed by the brain during top-down processing of visual input, we conclude that top-down modulation of visual processing is not purely predictive in nature: mood, in this case manipulated by music, may also directly alter the way we perceive the world.

  8. Altered Perspectives: Immersive Environments

    Science.gov (United States)

    Shipman, J. S.; Webley, P. W.

    2016-12-01

    Immersive environments provide an exciting experiential technology to visualize the natural world. Given the increasing accessibility of 360o cameras and virtual reality headsets we are now able to visualize artistic principles and scientific concepts in a fully immersive environment. The technology has become popular for photographers as well as designers, industry, educational groups, and museums. Here we show a sci-art perspective on the use of optics and light in the capture and manipulation of 360o images and video of geologic phenomena and cultural heritage sites in Alaska, England, and France. Additionally, we will generate intentionally altered perspectives to lend a surrealistic quality to the landscapes. Locations include the Catacombs of Paris, the Palace of Versailles, and the Northern Lights over Fairbanks, Alaska. Some 360o view cameras now use small portable dual lens technology extending beyond the 180o fish eye lens previously used, providing better coverage and image quality. Virtual reality headsets range in level of sophistication and cost, with the most affordable versions using smart phones and Google Cardboard viewers. The equipment used in this presentation includes a Ricoh Theta S spherical imaging camera. Here we will demonstrate the use of 360o imaging with attendees being able to be part of the immersive environment and experience our locations as if they were visiting themselves.

  9. Music alters visual perception.

    Directory of Open Access Journals (Sweden)

    Jacob Jolij

    Full Text Available BACKGROUND: Visual perception is not a passive process: in order to efficiently process visual input, the brain actively uses previous knowledge (e.g., memory and expectations about what the world should look like. However, perception is not only influenced by previous knowledge. Especially the perception of emotional stimuli is influenced by the emotional state of the observer. In other words, how we perceive the world does not only depend on what we know of the world, but also by how we feel. In this study, we further investigated the relation between mood and perception. METHODS AND FINDINGS: We let observers do a difficult stimulus detection task, in which they had to detect schematic happy and sad faces embedded in noise. Mood was manipulated by means of music. We found that observers were more accurate in detecting faces congruent with their mood, corroborating earlier research. However, in trials in which no actual face was presented, observers made a significant number of false alarms. The content of these false alarms, or illusory percepts, was strongly influenced by the observers' mood. CONCLUSIONS: As illusory percepts are believed to reflect the content of internal representations that are employed by the brain during top-down processing of visual input, we conclude that top-down modulation of visual processing is not purely predictive in nature: mood, in this case manipulated by music, may also directly alter the way we perceive the world.

  10. Electric Motor Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Bennion, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-01

    Thermal management enables more efficient and cost-effective motors. This Annual Merit Review presentation describes the technical accomplishments and progress in electric motor thermal management R&D over the last year. This project supports a broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management.

  11. Thermal Performance Benchmarking (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, G.

    2014-11-01

    This project will benchmark the thermal characteristics of automotive power electronics and electric motor thermal management systems. Recent vehicle systems will be benchmarked to establish baseline metrics, evaluate advantages and disadvantages of different thermal management systems, and identify areas of improvement to advance the state-of-the-art.

  12. Degraded Environments Alter Prey Risk Assessment

    Science.gov (United States)

    Lönnstedt, Oona M; McCormick, Mark I; Chivers, Douglas P

    2013-01-01

    Elevated water temperatures, a decrease in ocean pH, and an increasing prevalence of severe storms have lead to bleaching and death of the hard corals that underpin coral reef ecosystems. As coral cover declines, fish diversity and abundance declines. How degradation of coral reefs affects behavior of reef inhabitants is unknown. Here, we demonstrate that risk assessment behaviors of prey are severely affected by coral degradation. Juvenile damselfish were exposed to visual and olfactory indicators of predation risk in healthy live, thermally bleached, and dead coral in a series of laboratory and field experiments. While fish still responded to visual cues in all habitats, they did not respond to olfactory indicators of risk in dead coral habitats, likely as a result of alteration or degradation of chemical cues. These cues are critical for learning and avoiding predators, and a failure to respond can have dramatic repercussions for survival and recruitment. PMID:23403754

  13. Hydrothermal alteration at Roosevelt Hot Springs KGRA: DDH 1976-1

    Energy Technology Data Exchange (ETDEWEB)

    Bryant, N.L.; Parry, W.T.

    1977-09-01

    Hot waters of the Roosevelt Thermal Area, Utah, have altered granitic rocks and detritus of the Mineral Range pluton, Utah. Alteration and mineral deposition recognized in a 200' drill core from DDH 1-76 is most intense in the upper 100 feet which consists of altered alluvium and opal deposits; the lower 100 feet is weakly altered quartz monzonite. Petrographic, x-ray, and chemical methods were used to characterize systematic changes in chemistry and mineralogy. Comparison of the alteration mineral assemblages with known water chemistry and equilibrium activity diagrams suggests that a simple solution equilibrium model cannot account for the alteration. A model is proposed in which upward moving thermal water supersaturated with respect to quartz and a downward moving cool water undersaturated with respect to quartz produces the observed alteration. An estimate of the heat flow contributions from hydrothermal alteration was made by calculating reaction enthalpies for alteration reactions at each depth. The estimated heat flow varied from .02 HFU (for 200' depth, 400,000 yr duration, and no sulfur oxidation) to 67 HFU (for 5,000' depth, 1,000 yr duration, and all sulfur oxidized from sulfide). Heat flow contributions from hydrothermal alteration are comparable with those from a cooling granitic magma.

  14. Delamination-Indicating Thermal Barrier Coatings

    Science.gov (United States)

    Eldridge, Jeffrey I.

    2007-01-01

    The risk of premature failure of thermal barrier coatings (TBCs), typically composed of yttria-stabilized zirconia (YSZ), compromises the reliability of TBCs used to provide thermal protection for turbine engine components. Unfortunately, TBC delamination proceeds well beneath the TBC surface and cannot be monitored by visible inspection. Nondestructive diagnostic tools that could reliably probe the subsurface damage state of TBCs would alleviate the risk of TBC premature failure by indicating when the TBC needs to be replaced before the level of TBC damage threatens engine performance or safety. To meet this need, a new coating design for thermal barrier coatings (TBCs) that are self-indicating for delamination has been successfully implemented by incorporating a europium-doped luminescent sublayer at the base of a TBC composed of YSZ. The luminescent sublayer has the same YSZ composition as the rest of the TBC except for the addition of low-level europium doping and therefore does not alter TBC performance.

  15. Thermal impact of magmatism in subduction zones

    Science.gov (United States)

    Rees Jones, David W.; Katz, Richard F.; Tian, Meng; Rudge, John F.

    2018-01-01

    Magmatism in subduction zones builds continental crust and causes most of Earth's subaerial volcanism. The production rate and composition of magmas are controlled by the thermal structure of subduction zones. A range of geochemical and heat flow evidence has recently converged to indicate that subduction zones are hotter at lithospheric depths beneath the arc than predicted by canonical thermomechanical models, which neglect magmatism. We show that this discrepancy can be resolved by consideration of the heat transported by magma. In our one- and two-dimensional numerical models and scaling analysis, magmatic transport of sensible and latent heat locally alters the thermal structure of canonical models by ∼300 K, increasing predicted surface heat flow and mid-lithospheric temperatures to observed values. We find the advection of sensible heat to be larger than the deposition of latent heat. Based on these results we conclude that thermal transport by magma migration affects the chemistry and the location of arc volcanoes.

  16. Thermal Management and Thermal Protection Systems

    Science.gov (United States)

    Hasnain, Aqib

    2016-01-01

    During my internship in the Thermal Design Branch (ES3), I contributed to two main projects: i) novel passive thermal management system for future human exploration, ii) AVCOAT undercut thermal analysis. i) As NASA prepares to further expand human and robotic presence in space, it is well known that spacecraft architectures will be challenged with unprecedented thermal environments. Future exploration activities will have the need of thermal management systems that can provide higher reliability, mass and power reduction and increased performance. In an effort to start addressing the current technical gaps the NASA Johnson Space Center Passive Thermal Discipline has engaged in technology development activities. One of these activities was done through an in-house Passive Thermal Management System (PTMS) design for a lunar lander. The proposed PTMS, functional in both microgravity and gravity environments, consists of three main components: a heat spreader, a novel hybrid wick Variable Conductance Heat Pipe (VCHP), and a radiator. The aim of this PTMS is to keep electronics on a vehicle within their temperature limits (0 and 50 C for the current design) during all mission phases including multiple lunar day/night cycles. The VCHP was tested to verify its thermal performance. I created a thermal math model using Thermal Desktop (TD) and analyzed it to predict the PTMS performance. After testing, the test data provided a means to correlate the thermal math model. This correlation took into account conduction and convection heat transfer, representing the actual benchtop test. Since this PTMS is proposed for space missions, a vacuum test will be taking place to provide confidence that the system is functional in space environments. Therefore, the model was modified to include a vacuum chamber with a liquid nitrogen shroud while taking into account conduction and radiation heat transfer. Infrared Lamps were modelled and introduced into the model to simulate the sun

  17. Quantum Thermal Transistor.

    Science.gov (United States)

    Joulain, Karl; Drevillon, Jérémie; Ezzahri, Younès; Ordonez-Miranda, Jose

    2016-05-20

    We demonstrate that a thermal transistor can be made up with a quantum system of three interacting subsystems, coupled to a thermal reservoir each. This thermal transistor is analogous to an electronic bipolar one with the ability to control the thermal currents at the collector and at the emitter with the imposed thermal current at the base. This is achieved by determining the heat fluxes by means of the strong-coupling formalism. For the case of three interacting spins, in which one of them is coupled to the other two, that are not directly coupled, it is shown that high amplification can be obtained in a wide range of energy parameters and temperatures. The proposed quantum transistor could, in principle, be used to develop devices such as a thermal modulator and a thermal amplifier in nanosystems.

  18. Global geologic context for rock types and surface alteration on Mars

    Science.gov (United States)

    Wyatt, M.B.; McSween, H.Y.; Tanaka, K.L.; Head, J. W.

    2004-01-01

    Petrologic interpretations of thermal emission spectra from Mars orbiting spacecraft indicate the widespread occurrence of surfaces having basaltic and either andesitic or partly altered basalt compositions. Global concentration of ice-rich mantle deposits and near-surface ice at middle to high latitudes and their spatial correlation with andesitic or partly altered basalt materials favor the alteration hypothesis. We propose the formation of these units through limited chemical weathering from basalt interactions with icy mantles deposited during periods of high obliquity. Alteration of sediments in the northern lowlands depocenter may have been enhanced by temporary standing bodies of water and ice. ?? 2004 Geological Society of America.

  19. Thermal /Soret/ diffusion effects on interfacial mass transport rates

    Science.gov (United States)

    Rosner, D. E.

    1980-01-01

    It is shown that thermal (Soret) diffusion significantly alters convective mass transport rates and important transition temperatures in highly nonisothermal flow systems involving the transport of 'heavy' species (vapors or particles). Introduction of the Soret transport term is shown to result in mass transfer effects similar to those of 'suction' and a homogeneous chemical 'sink'. It is pointed out that this analogy provides a simple method of correlating and predicting thermal diffusion effects in the abovementioned systems.

  20. Genetic alteration in hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoo Chul; Kang, Tae Woong; Lee, Jin Oh [Korea Cancer Center Hospital of Korea Atomic Energy Research Institute, Seoul (Korea, Republic of)

    1994-12-01

    Cancer of stomach, colon and liver are a group of the most common cancer in Korea. However, results with current therapeutic modalities are still unsatisfactory. The intensive efforts have been made to understand basic pathogenesis and to find better therapeutic tools for the treatment of this miserable disease. We studied the alteration of tumor suppressor genes and oncogenes in hepatocellular carcinoma in Korea. We found that alteration of Rb gene, APC were 33 %, 13 % respectively. But alterations of oncogenes such as myc, ras and mdm2 were rarely found. Our results suggests that HBV may act as oncogenic role in hepatocarcinogenesis instead of oncogenes. 6 figs, 2 tabs. (Author).

  1. Thermal Imaging in Aviation

    Directory of Open Access Journals (Sweden)

    Marek Štumper

    2015-10-01

    Full Text Available This article focuses on the use of thermal imaging in aviation. In the never ending pursuit of lower costs, the Thermal Imaging offers shorter inspection times thanks to its application in aircraft inspections and can reduce the number of costly goarounds using the Enhanced Vision System, which also increases safety in one of the most dangerous parts of flight. Thermal Imaging also offers solutions for Airport Perimeter Security and it can be used for construction of ground surveillance system.

  2. Thermal waveguide OPO.

    Science.gov (United States)

    Lin, S T; Lin, Y Y; Wang, T D; Huang, Y C

    2010-01-18

    We report a mid-infrared, CW singly resonant optical parametric oscillator (OPO) with a thermally induced waveguide in its gain crystal. We measured a numerical aperture of 0.0062 for the waveguide at 80-W intracavity power at 3.2 microm. This thermal-guiding effect benefits to the stable operation of an OPO and improves the parametric conversion efficiency by more than a factor of two when compared with that without thermal guiding.

  3. Thermal Hyperbolic Metamaterials

    OpenAIRE

    Guo, Yu; Jacob, Zubin

    2013-01-01

    We explore the near-field radiative thermal energy transfer properties of hyperbolic metamaterials. The presence of unique electromagnetic states in a broad bandwidth leads to super-planckian thermal energy transfer between metamaterials separated by a nano-gap. We consider practical phonon-polaritonic metamaterials for thermal engineering in the mid-infrared range and show that the effect exists in spite of the losses, absorption and finite unit cell size. For thermophotovoltaic energy conve...

  4. Building Thermal Models

    Science.gov (United States)

    Peabody, Hume L.

    2017-01-01

    This presentation is meant to be an overview of the model building process It is based on typical techniques (Monte Carlo Ray Tracing for radiation exchange, Lumped Parameter, Finite Difference for thermal solution) used by the aerospace industry This is not intended to be a "How to Use ThermalDesktop" course. It is intended to be a "How to Build Thermal Models" course and the techniques will be demonstrated using the capabilities of ThermalDesktop (TD). Other codes may or may not have similar capabilities. The General Model Building Process can be broken into four top level steps: 1. Build Model; 2. Check Model; 3. Execute Model; 4. Verify Results.

  5. Thermal microactuator dimension analysis

    Science.gov (United States)

    Azman, N. D.; Ong, N. R.; Aziz, M. H. A.; Alcain, J. B.; Haimi, W. M. W. N.; Sauli, Z.

    2017-09-01

    The focus of this study was to analyse the stress and thermal flow of thermal microactuator with different type of materials and parameter using COMSOL Multiphysics software. Simulations were conducted on the existing thermal actuator and integrated it to be more efficient, low cost and low power consumption. In this simulation, the U-shaped actuator was designed and five different materials of the microactuator were studied. The result showed that Si Polycrystalline was the most suitable material used to produce thermal actuator for commercialization.

  6. Thermal Performance Benchmarking

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xuhui; Moreno, Gilbert; Bennion, Kevin

    2016-06-07

    The goal for this project is to thoroughly characterize the thermal performance of state-of-the-art (SOA) in-production automotive power electronics and electric motor thermal management systems. Information obtained from these studies will be used to: evaluate advantages and disadvantages of different thermal management strategies; establish baseline metrics for the thermal management systems; identify methods of improvement to advance the SOA; increase the publicly available information related to automotive traction-drive thermal management systems; help guide future electric drive technologies (EDT) research and development (R&D) efforts. The thermal performance results combined with component efficiency and heat generation information obtained by Oak Ridge National Laboratory (ORNL) may then be used to determine the operating temperatures for the EDT components under drive-cycle conditions. In FY16, the 2012 Nissan LEAF power electronics and 2014 Honda Accord Hybrid power electronics thermal management system were characterized. Comparison of the two power electronics thermal management systems was also conducted to provide insight into the various cooling strategies to understand the current SOA in thermal management for automotive power electronics and electric motors.

  7. Theory of thermal stresses

    CERN Document Server

    Boley, Bruno A

    1997-01-01

    Highly regarded text presents detailed discussion of fundamental aspects of theory, background, problems with detailed solutions. Basics of thermoelasticity, heat transfer theory, thermal stress analysis, more. 1985 edition.

  8. Monitoring Thermal Pollution in Rivers Downstream of Dams with Landsat ETM+ Thermal Infrared Images

    Directory of Open Access Journals (Sweden)

    Feng Ling

    2017-11-01

    Full Text Available Dams play a significant role in altering the spatial pattern of temperature in rivers and contribute to thermal pollution, which greatly affects the river aquatic ecosystems. Understanding the temporal and spatial variation of thermal pollution caused by dams is important to prevent or mitigate its harmful effect. Assessments based on in-situ measurements are often limited in practice because of the inaccessibility of water temperature records and the scarcity of gauges along rivers. By contrast, thermal infrared remote sensing provides an alternative approach to monitor thermal pollution downstream of dams in large rivers, because it can cover a large area and observe the same zone repeatedly. In this study, Landsat Enhanced Thematic Mapper Plus (ETM+ thermal infrared imagery were applied to assess the thermal pollution caused by two dams, the Geheyan Dam and the Gaobazhou Dam, located on the Qingjiang River, a tributary of the Yangtze River downstream of the Three Gorges Reservoir in Central China. The spatial and temporal characteristics of thermal pollution were analyzed with water temperatures estimated from 54 cloud-free Landsat ETM+ scenes acquired in the period from 2000 to 2014. The results show that water temperatures downstream of both dams are much cooler than those upstream of both dams in summer, and the water temperature remains stable along the river in winter, showing evident characteristic of the thermal pollution caused by dams. The area affected by the Geheyan Dam reaches beyond 20 km along the downstream river, and that affected by the Gaobazhou Dam extends beyond the point where the Qingjiang River enters the Yangtze River. Considering the long time series and global coverage of Landsat ETM+ imagery, the proposed technique in the current study provides a promising method for globally monitoring the thermal pollution caused by dams in large rivers.

  9. Hydrogen isotope alteration of normal alkanes during artificial maturation experiments

    Science.gov (United States)

    Wang, C.; Eley, Y.; Oakes, A.; Hren, M. T.

    2016-12-01

    Hydrogen isotopes of normal alkanes provide a record of past climate, hydrocarbon source and migration, and thermal history. Numerous authors have investigated the preservation potential of organic compounds during burial diagenesis and developed a range of molecular indicators of thermal maturity. A key uncertainty in application of organic biomarkers for paleoenvironmental work is how the δD values of individual molecular compounds changes during burial heating and thermal cracking. Studies suggest that n-alkanes are unlikely to exchange hydrogen at modest temperatures (below 150°C) over geologic time, however there is still debate over the potential for alteration of primary isotopic signatures due to the combined effect of exchange and cracking of more complex molecules. We conducted a suite of heating experiments in ambient air and oxygen-free systems using pure alkane mixtures and natural soil extracts to evaluate the preservation potential of the hydrogen isotopic composition of both short (nC20) carbon chain n-alkanes. Our data show that for pure mixtures, there is a positive shift in the δD of long carbon chains during heating of up to 12‰ and a negative shift in short chains of up to 28‰. Experiments with natural sediment extracts show 2H enrichment of long carbon chains during heating in both ambient air and oxygen free systems, and at temperatures below 150°C. These changes are accompanied by shifts in the carbon preference and average chain length. Experimental data show that there is potential for 2H/1H alteration of long-carbon chain normal alkanes during shallow burial, however these changes rarely exceed 10-15‰ before compounds are degraded to quantities below useful abundances for isotope measurements. A potentially significant result is that low temperature alteration of organics within sediments can shift the average chain length, particularly in the presence of oxygen. Thus, lithology and gas permeability may play an important role in

  10. Variable pressure thermal insulating jacket

    Science.gov (United States)

    Nelson, Paul A.; Malecha, Richard F.; Chilenskas, Albert A.

    1994-01-01

    A device for controlled insulation of a thermal device. The device includes a thermal jacket with a closed volume able to be evacuated to form an insulating jacket around the thermal source. A getter material is in communcation with the closed volume of the thermal jacket. The getter material can absorb and desorb a control gas to control gas pressure in the volume of the thermal jacket to control thermal conductivity in the thermal jacket.

  11. Hypothesis tests for hydrologic alteration

    Science.gov (United States)

    Kroll, Charles N.; Croteau, Kelly E.; Vogel, Richard M.

    2015-11-01

    Hydrologic systems can be altered by anthropogenic and climatic influences. While there are a number of statistical frameworks for describing and evaluating the extent of hydrologic alteration, here we present a new framework for assessing whether statistically significant hydrologic alteration has occurred, or whether the shift in the hydrologic regime is consistent with the natural variability of the system. Four hypothesis tests based on shifts of flow duration curves (FDCs) are developed and tested using three different experimental designs based on different strategies for resampling of annual FDCs. The four hypothesis tests examined are the Kolmogorov-Smirnov (KS), Kuiper (K), confidence interval (CI), and ecosurplus and ecodeficit (Eco). Here 117 streamflow sites that have potentially undergone hydrologic alteration due to reservoir construction are examined. 20 years of pre-reservoir record is used to develop the critical value of the test statistic for type I errors of 5% and 10%, while 10 years of post-alteration record is used to examine the power of each test. The best experimental design, based on calculating the mean annual FDC from an exhaustive jackknife resampling regime, provided a larger number of unique values of each test statistic and properly reproduced type I errors. Of the four tests, the CI test consistently had the highest power, while the K test had the second highest power; KS and Eco always had the lowest power. The power of the CI test appeared related to the storage ratio of the reservoir, a rough measure of the hydrologic alteration of the system.

  12. Selective thermal emission from thin-film metasurfaces

    Science.gov (United States)

    Streyer, W.; Law, S.; Mason, J.; Adams, D. C.; Rooney, G.; Jacobs, T.; Wasserman, D.

    2013-09-01

    The mid-infrared (mid-IR), as the spectral range where all finite temperature biological and mechanical objects emit thermal radiation, and where numerous molecular species have strong vibrational absorption resonances, is of significant importance for both security and sensing applications. The design of materials with engineered absorption resonances, which by Kirchoff's Law, should give strongly selective emission at the design resonance upon thermal excitation, allows for the control of the spectral character of the material's thermal emission. Designed as a thin film coating, these structures can be applied to grey-body emitters to shift the grey-body thermal emission into predetermined spectral bands, altering their appearance on a thermal imaging system. Here we demonstrate strongly selective mid-infrared absorption and thermal emission from three classes of subwavelength thin-film materials. First, we demonstrate selective thermal emission from patterned, commerciallyavailable steel films, via selective out-coupling of thermally-excited surface modes. Subsequently, we show nearperfect absorption (and strongly selective thermal emission) for wavelengths between 5 - 9μm with patterned metal-dielectric-metal structures. Finally, we demonstrate strong absorption from large area, unpatterned, thinfilm high-index dielectric coatings on highly-doped Si substrates, tunable across the mid-IR (5 - 12μm). Our results are compared to numerical simulations, as well as analytical models, with good agreement between experiments and models.

  13. A thermal ground cloak

    Science.gov (United States)

    Yang, Tianzhi; Wu, Qinghe; Xu, Weikai; Liu, Di; Huang, Lujun; Chen, Fei

    2016-02-01

    The thermal cloak has been a long-standing scientific dream of researchers and engineers. Recently thermal metamaterials with man-made micro-structure have been presented based on the principle of transformation optics (TO). This new concept has received considerable attention, which is a powerful tool for manipulating heat flux in thermal imaging systems. However, the inherent material singularity has long been a captivation of experimental realization. As an alternative method, the scattering-cancellation-based cloak (or bi-layer thermal cloak) has been presented to remove the singularity for achieving the same cloaking performance. Nevertheless, such strategy needs prerequisite knowledge (geometry and conductivity) of the object to be cloaked. In this paper, a new thermal ground cloak is presented to overcome the limitations. The device is designed, fabricated and measured to verify the thermal cloaking performance. We experimentally show that the remarkably low complexity of the device can fully and effectively be manipulated using realizable transformation thermal devices. More importantly, this thermal ground cloak is designed to exclude heat flux without knowing the information of the cloaked object.

  14. Power Electronics Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilberto [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-07

    Thermal modeling was conducted to evaluate and develop thermal management strategies for high-temperature wide-bandgap (WBG)-based power electronics systems. WBG device temperatures of 175 degrees C to 250 degrees C were modeled under various under-hood temperature environments. Modeling result were used to identify the most effective capacitor cooling strategies under high device temperature conditions.

  15. Thermally exfoliated graphite oxide

    Science.gov (United States)

    Prud'Homme, Robert K. (Inventor); Aksay, Ilhan A. (Inventor); Abdala, Ahmed (Inventor)

    2011-01-01

    A modified graphite oxide material contains a thermally exfoliated graphite oxide with a surface area of from about 300 sq m/g to 2600 sq m/g, wherein the thermally exfoliated graphite oxide displays no signature of the original graphite and/or graphite oxide, as determined by X-ray diffraction.

  16. Conceptual thermal design

    NARCIS (Netherlands)

    Strijk, R.

    2008-01-01

    Present thermal design tools and methods insufficiently support the development of structural concepts engaged by typical practicing designers. Research described in this thesis identifies the main thermal design problems in practice. In addition, models and methods are developed that support an

  17. Thermal energy storage

    Science.gov (United States)

    1980-01-01

    The planning and implementation of activities associated with lead center management role and the technical accomplishments pertaining to high temperature thermal energy storage subsystems are described. Major elements reported are: (1) program definition and assessment; (2) research and technology development; (3) industrial storage applications; (4) solar thermal power storage applications; and (5) building heating and cooling applications.

  18. Thermal flow micro sensors

    NARCIS (Netherlands)

    Elwenspoek, Michael Curt

    1999-01-01

    A review is given on sensors fabricated by silicon micromachining technology using the thermal domain for the measurement of fluid flow. Attention is paid especially to performance and geometry of the sensors. Three basic types of thermal flow sensors are discussed: anemometers, calorimetric flow

  19. High Thermal Conductivity Materials

    CERN Document Server

    Shinde, Subhash L

    2006-01-01

    Thermal management has become a ‘hot’ field in recent years due to a need to obtain high performance levels in many devices used in such diverse areas as space science, mainframe and desktop computers, optoelectronics and even Formula One racing cars! Thermal solutions require not just taking care of very high thermal flux, but also ‘hot spots’, where the flux densities can exceed 200 W/cm2. High thermal conductivity materials play an important role in addressing thermal management issues. This volume provides readers a basic understanding of the thermal conduction mechanisms in these materials and discusses how the thermal conductivity may be related to their crystal structures as well as microstructures developed as a result of their processing history. The techniques for accurate measurement of these properties on large as well as small scales have been reviewed. Detailed information on the thermal conductivity of diverse materials including aluminum nitride (AlN), silicon carbide (SiC), diamond, a...

  20. Paradoxes of Thermal Radiation

    Science.gov (United States)

    Besson, U.

    2009-01-01

    This paper presents an analysis of the thermal behaviour of objects exposed to a solar-type flux of thermal radiation. It aims to clarify certain apparent inconsistencies between theory and observation, and to give a detailed exposition of some critical points that physics textbooks usually treat in an insufficient or incorrect way. In particular,…

  1. Thermal Activated Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Pasold, Anke

    2015-01-01

    search procedure, the combination of materials and their bonding temperature is found in relation to the envelope effect on a thermal environment inside a defined space. This allows the designer to articulate dynamic composites with time-based thermal functionality, related to the material dynamics...

  2. Radiative Bistability and Thermal Memory

    Science.gov (United States)

    Kubytskyi, Viacheslav; Biehs, Svend-Age; Ben-Abdallah, Philippe

    2014-08-01

    We predict the existence of a thermal bistability in many-body systems out of thermal equilibrium which exchange heat by thermal radiation using insulator-metal transition materials. We propose a writing-reading procedure and demonstrate the possibility to exploit the thermal bistability to make a volatile thermal memory. We show that this thermal memory can be used to store heat and thermal information (via an encoding temperature) for arbitrary long times. The radiative thermal bistability could find broad applications in the domains of thermal management, information processing, and energy storage.

  3. Battery Pack Thermal Design

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, Ahmad

    2016-06-14

    This presentation describes the thermal design of battery packs at the National Renewable Energy Laboratory. A battery thermal management system essential for xEVs for both normal operation during daily driving (achieving life and performance) and off-normal operation during abuse conditions (achieving safety). The battery thermal management system needs to be optimized with the right tools for the lowest cost. Experimental tools such as NREL's isothermal battery calorimeter, thermal imaging, and heat transfer setups are needed. Thermal models and computer-aided engineering tools are useful for robust designs. During abuse conditions, designs should prevent cell-to-cell propagation in a module/pack (i.e., keep the fire small and manageable). NREL's battery ISC device can be used for evaluating the robustness of a module/pack to cell-to-cell propagation.

  4. Near-field/altered-zone models report

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, E. L., LLNL

    1998-03-01

    The U.S. Department of Energy is studying Yucca Mountain as the possible site for the first underground repository for permanent disposal of spent fuel from commercial nuclear reactors as well as for other types high-level nuclear waste. Emplacement of high-level radioactive waste, especially commercial spent nuclear fuel (CSNF), in Yucca Mountain will release a large amount of heat into the rock above and below the repository. The heating rate will decrease with time, creating a thermal pulse. Over a period of several thousand years, the rock temperature will rise initially, then drop when the production of decay heat falls below the rate at which heat escapes from the hot zone. Besides raising the rock temperature, much of this heat will vaporize water, which will then condense in cooler regions. The condensate is likely to form a gravity-driven heat pipe above the repository, creating the possibility that water may drain back onto the waste packages (WPs) or that it may ''shed'' through the pillars between emplacement drifts. The long-term importance of these effects has been investigated through the development, testing, and application of thermohydrologic (TH) models. Other effects, such coupled chemical and mechanical processes, may also influence the movement of water above, within, and below the emplacement drifts. A recent report on thermally driven coupled processes (Hardin and Chesnut, 1997) provides a qualitative assessment of the probable significance of these processes for the Yucca Mountain Site Characterization Project (YMSCP) and is the phenomenological framework for the present report. This report describes the conceptual and numerical models that have been developed to predict the thermal, mechanical, hydrologic, and chemical responses to the cumulative heat production of the potential host rock at Yucca Mountain. As proposed, the repository horizon will be situated within the Topopah Spring tuff, in the adjacent middle

  5. Hydrothermal alteration at Roosevelt Hot Springs KGRA - DDH 1976-1

    Energy Technology Data Exchange (ETDEWEB)

    Bryant, N.L.; Parry, W.T.

    1977-09-01

    Hot waters of the Roosevelt Thermal Area, Utah, have altered granitic rocks and detritus of the Mineral Range pluton, Utah. Petrographic, x-ray, and chemical methods were used to characterize systematic changes in chemistry and mineralogy. Major alteration zones include: 1) an advanced argillic zone in the upper 30 feet of altered detritus containing alunite, opal, vermiculite, and relic quartz; 2) an argillic zone from 30 feet to 105 feet containing kaolinite, muscovite, and minor alunite; and 3) a propylitic zone from 105 to 200 feet containing muscovite, pyrite, marcasite, montmorillonite, and chlorite in weakly altered quartz monzonite. Comparison of the alternation mineral assemblages with known water chemistry and equilibrium activity diagrams suggests that a simple solution equilibrium model cannot account for the alteration. A model is proposed in which upward moving thermal water supersaturated with respect to quartz and a downward moving cool water undersaturated with respect to quartz produces the observed alteration. An estimate of the heat flow contributions from hydrothermal alteration was made by calculating reaction enthalpies for alteration reactions at each depth.

  6. Alterations undergone in the thermal behavior of the Church of the Trinidad of Segovia due to the modification of its urban surroundings; Alteraciones sufridas en el comportamiento termico de la Iglesia de la Trinidad de Segovia debida a la modificacion de su entorno urbano

    Energy Technology Data Exchange (ETDEWEB)

    Arroba, M.; Grau, J.; Alanon, P.; Piez-Pastor, C.; Garcia, J.

    2008-07-01

    As part of an investigation project on three medieval churches of Segovia, financed by the Junta de Castilla y Leon, study of thermal behaviour of the Iglesia de la Trinidad was carried out. We expected to find the conventional behaviour of this type of building, with high roofs and wide stone walls: different temperatures in different walls, according to their height and situation. However, after studying these temperatures we observed there was not such difference, at least to demonstrate the existence of a passive solar heating. After studying the possible causes of this anomaly we realized it was caused by changes in urban environment. (Author)

  7. Ceramic Thermal Barriers For Dirty-Fuel Turbines

    Science.gov (United States)

    Miller, Robert A.

    1988-01-01

    Report discusses performances of ceramic thermal-barrier coating materials for use in electric-utility gas-turbine engines. Variations of standard coating evaluated in search for coating resistant to dirty fuel. Variations included alterations of level of yttria, replacement of yttria by other stabilizers, controlling surface density (by plasma spray processing, infiltration, laser glazing, or sputtering), and interface treatments.

  8. Thermally-related safety issues associated with thermal batteries.

    Energy Technology Data Exchange (ETDEWEB)

    Guidotti, Ronald Armand

    2006-06-01

    Thermal batteries can experience thermal runaway under certain usage conditions. This can lead to safety issues for personnel and cause damage to associated test equipment if the battery thermally self destructs. This report discusses a number of thermal and design related issues that can lead to catastrophic destruction of thermal batteries under certain conditions. Contributing factors are identified and mitigating actions are presented to minimize or prevent undesirable thermal runaway.

  9. Thermal imaging in medicine

    Directory of Open Access Journals (Sweden)

    Jaka Ogorevc

    2015-12-01

    Full Text Available AbstractIntroduction: Body temperature monitoring is one of the oldest and still one of the most basic diagnostic methods in medicine. In recent years thermal imaging has been increasingly used in measurements of body temperature for diagnostic purposes. Thermal imaging is non-invasive, non-contact method for measuring surface body temperature. Method is quick, painless and patient is not exposed to ionizing radiation or any other body burden.Application of thermal imaging in medicine: Pathological conditions can be indicated as hyper- or hypothermic patterns in many cases. Thermal imaging is presented as a diagnostic method, which can detect such thermal anomalies. This article provides an overview of the thermal imaging applications in various fields of medicine. Thermal imaging has proven to be a suitable method for human febrile temperature screening, for the detection of sites of fractures and infections, a reliable diagnostic tool in the detection of breast cancer and determining the type of skin cancer tumour. It is useful in monitoring the course of a therapy after spinal cord injury, in the detection of food allergies and detecting complications at hemodialysis and is also very effective at the course of treatment of breast reconstruction after mastectomy. With thermal imaging is possible to determine the degrees of burns and early detection of osteomyelitis in diabetic foot phenomenon. The most common and the oldest application of thermal imaging in medicine is the field of rheumatology.Recommendations for use and standards: Essential performance of a thermal imaging camera, measurement method, preparation of a patient and environmental conditions are very important for proper interpretation of measurement results in medical applications of thermal imaging. Standard for screening thermographs was formed for the human febrile temperature screening application.Conclusion: Based on presented examples it is shown that thermal imaging can

  10. Consequences of altering rubisco regulation

    Energy Technology Data Exchange (ETDEWEB)

    Salvucci, Michael [US Dept. of Agriculture (USDA)., Ames, IA (United States)

    2013-12-31

    Research examined the thermal stability and propensity for aggregation of wild type and the C- and N-terminally modified forms of activase to determine if loss of activity under heat stress is dependent on protein aggregation. The results showed that 1) loss of activity at high temperature is independent of aggregation; 2) activase with both C- and N-terminal S-Tags are more susceptible to aggregation than wild type activase, 3) aggregation is highly dependent on the concentration of Mg2+ and 4) the ATP analog, ATPgammaS, protects against both thermal inactivation and aggregation.

  11. Thermal properties of nanofluids.

    Science.gov (United States)

    Philip, John; Shima, P D

    2012-11-15

    Colloidal suspensions of fine nanomaterials in the size range of 1-100 nm in carrier fluids are known as nanofluids. For the last one decade, nanofluids have been a topic of intense research due to their enhanced thermal properties and possible heat transfer applications. Miniaturization and increased operating speeds of gadgets warranted the need for new and innovative cooling concepts for better performance. The low thermal conductivity of conventional heat transfer fluid has been a serious impediment for improving the performance and compactness of engineering equipments. Initial studies on thermal conductivity of suspensions with micrometer-sized particles encountered problems of rapid settling of particles, clogging of flow channels and increased pressure drop in the fluid. These problems are resolved by using dispersions of fine nanometer-sized particles. Despite numerous experimental and theoretical studies, it is still unclear whether the thermal conductivity enhancement in nanofluids is anomalous or within the predictions of effective medium theory. Further, many reports on thermal conductivity of nanofluids are conflicting due to the complex issues associated with the surface chemistry of nanofluids. This review provides an overview of recent advances in the field of nanofluids, especially the important material properties that affect the thermal properties of nanofluids and novel approaches to achieve extremely high thermal conductivities. The background information is also provided for beginners to better understand the subject. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Thermalized axion inflation

    Science.gov (United States)

    Ferreira, Ricardo Z.; Notari, Alessio

    2017-09-01

    We analyze the dynamics of inflationary models with a coupling of the inflaton phi to gauge fields of the form phi F tilde F/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= dot phi/(2fH), 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 ξgtrsim2.9, 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 ξgtrsim3.4 however, observations require ξgtrsim6, 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 Teq simeq ξ H/bar g where bar g is the effective gauge coupling. Finally, we estimate the spectrum of perturbations if phi is thermal and find that the tensor to scalar ratio is suppressed by H/(2T), if tensors do not thermalize.

  13. Advanced thermal management materials

    CERN Document Server

    Jiang, Guosheng; Kuang, Ken

    2012-01-01

    ""Advanced Thermal Management Materials"" provides a comprehensive and hands-on treatise on the importance of thermal packaging in high performance systems. These systems, ranging from active electronically-scanned radar arrays to web servers, require components that can dissipate heat efficiently. This requires materials capable of dissipating heat and maintaining compatibility with the packaging and dye. Its coverage includes all aspects of thermal management materials, both traditional and non-traditional, with an emphasis on metal based materials. An in-depth discussion of properties and m

  14. Alternatives to eigenstate thermalization.

    Science.gov (United States)

    Rigol, Marcos; Srednicki, Mark

    2012-03-16

    An isolated quantum many-body system in an initial pure state will come to thermal equilibrium if it satisfies the eigenstate thermalization hypothesis (ETH). We consider alternatives to ETH that have been proposed. We first show that von Neumann's quantum ergodic theorem relies on an assumption that is essentially equivalent to ETH. We also investigate whether, following a sudden quench, special classes of pure states can lead to thermal behavior in systems that do not obey ETH, namely, integrable systems. We find examples of this, but only for initial states that obeyed ETH before the quench.

  15. Thermal energy transformer

    Science.gov (United States)

    Berdahl, C. M.; Thiele, C. L. (Inventor)

    1979-01-01

    For use in combination with a heat engine, a thermal energy transformer is presented. It is comprised of a flux receiver having a first wall defining therein a radiation absorption cavity for converting solar flux to thermal energy, and a second wall defining an energy transfer wall for the heat engine. There is a heat pipe chamber interposed between the first and second walls having a working fluid disposed within the chamber and a wick lining the chamber for conducting the working fluid from the second wall to the first wall. Thermal energy is transferred from the radiation absorption cavity to the heat engine.

  16. Petrology of Amoeboid Olivine Aggregates in Antarctic CR Chondrites: Evidence for Aqueous Alteration and Shock Metamorphism

    Science.gov (United States)

    Komatsu, M.; Fagan, T. J.; Yamaguchi, A.; Mikouchi, T.; Yasutake, M.; Zolensky, M. E.

    2017-01-01

    CR chondrites are the group of carbonaceous chondrites that preserve records of formation of their components in the solar nebula. Although they are affected by aqueous alteration, many chondrules and CAIs are well-preserved, suggesting they have experienced little thermal metamorphism. We have been investigating the petrologic variations among the CR chondrites in Japanese-NIPR Antarctic meteorite collection. Especially we focused on the petrology of amoeboid olivine aggregates (AOAs) in order to understand secondary alteration on CR chondrite parent body. AOAs are composed of fine-grained forsteritic olivine and refractory minerals formed by condensation from solar nebula, and can be used as sensitive indicators of secondary alteration processes.

  17. Thermal cloak-concentrator

    Science.gov (United States)

    Shen, Xiangying; Li, Ying; Jiang, Chaoran; Ni, Yushan; Huang, Jiping

    2016-07-01

    For macroscopically manipulating heat flow at will, thermal metamaterials have opened a practical way, which possesses a single function, such as either cloaking or concentrating the flow of heat even though environmental temperature varies. By developing a theory of transformation heat transfer for multiple functions, here we introduce the concept of intelligent thermal metamaterials with a dual function, which is in contrast to the existing thermal metamaterials with single functions. By assembling homogeneous isotropic materials and shape-memory alloys, we experimentally fabricate a kind of intelligent thermal metamaterials, which can automatically change from a cloak (or concentrator) to a concentrator (or cloak) when the environmental temperature changes. This work paves an efficient way for a controllable gradient of heat, and also provides guidance both for arbitrarily manipulating the flow of heat and for efficiently designing similar intelligent metamaterials in other fields.

  18. Paradoxes of thermal radiation

    Energy Technology Data Exchange (ETDEWEB)

    Besson, U [Department of Physics ' A Volta' , University of Pavia, Via A Bassi 6, 27100 Pavia (Italy)], E-mail: ugo.besson@unipv.it

    2009-09-15

    This paper presents an analysis of the thermal behaviour of objects exposed to a solar-type flux of thermal radiation. It aims to clarify certain apparent inconsistencies between theory and observation, and to give a detailed exposition of some critical points that physics textbooks usually treat in an insufficient or incorrect way. In particular, the paper examines the equilibrium temperature reached by objects exposed to solar thermal radiation and the temperature difference between their illuminated and shaded sides. These problems are studied first by analysing the simple ideal case of an isolated object, subsequently by taking into account the thermal radiation emitted by the environment, and finally by considering also the heat exchange with the surrounding air. Some examples are developed and numerical data are provided. The topic is developed in a way that can be suitable for both undergraduate student and general physicist.

  19. Compliant thermal microactuators

    DEFF Research Database (Denmark)

    Jonsmann, Jacques; Sigmund, Ole; Bouwstra, Siebe

    1999-01-01

    Two dimensional compliant metallic thermal microactuators are designed using topology optimisation, and microfabricated using rapid prototyping techniques. Structures are characterised using advanced image analysis, yielding a very high precision. Characterised structures behave in a way which can...

  20. Compliant thermal microactuators

    DEFF Research Database (Denmark)

    Jonsmann, Jacques; Sigmund, Ole; Bouwstra, Siebe

    1999-01-01

    Two dimensional compliant metallic thermal microactuators are designed using topology optimisation, and microfabricated using rapid prototyping techniques. Structures are characterised using advanced image analysis, yielding a very high precision. Characterised structures behave in accordance...

  1. Thermal Properties Measurement Report

    Energy Technology Data Exchange (ETDEWEB)

    Carmack, Jon [Idaho National Lab. (INL), Idaho Falls, ID (United States); Braase, Lori [Idaho National Lab. (INL), Idaho Falls, ID (United States); Papesch, Cynthia [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hurley, David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tonks, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Yongfeng [Idaho National Lab. (INL), Idaho Falls, ID (United States); Gofryk, Krzysztof [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States); Fielding, Randy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Knight, Collin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Meyer, Mitch [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-08-01

    The Thermal Properties Measurement Report summarizes the research, development, installation, and initial use of significant experimental thermal property characterization capabilities at the INL in FY 2015. These new capabilities were used to characterize a U3Si2 (candidate Accident Tolerant) fuel sample fabricated at the INL. The ability to perform measurements at various length scales is important and provides additional data that is not currently in the literature. However, the real value of the data will be in accomplishing a phenomenological understanding of the thermal conductivity in fuels and the ties to predictive modeling. Thus, the MARMOT advanced modeling and simulation capability was utilized to illustrate how the microstructural data can be modeled and compared with bulk characterization data. A scientific method was established for thermal property measurement capability on irradiated nuclear fuel samples, which will be installed in the Irradiated Material Characterization Laboratory (IMCL).

  2. Graphene thermal flux transistor.

    Science.gov (United States)

    Shafranjuk, S E

    2016-11-24

    Insufficient flexibility of existing approaches to controlling the thermal transport in atomic monolayers limits their capability for use in many applications. Here, we examine the means of electrode doping to control the thermal flux Q due to phonons propagating along the atomic monolayer. We found that the frequency of the electron-restricted phonon scattering strongly depends on the concentration nC. of the electric charge carriers, established by the electric potentials applied to local gates. As a result of the electrode doping, nC is increased, causing a sharp rise in both the electrical conductivity and Seebeck coefficient, while the thermal conductivity tumbles. Therefore, the effect of the thermal transistor improves the figure of merit of nanoelectronic circuits.

  3. Thermal springs of Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Breckenridge, R.M.; Hinckley, B.S.

    1978-01-01

    This bulletin attempts, first, to provide a comprehensive inventory of the thermal springs of Wyoming; second, to explore the geologic and hydrologic factors producing these springs; and, third, to analyze the springs collectively as an indicator of the geothermal resources of the state. A general discussion of the state's geology and the mechanisms of thermal spring production, along with a brief comparison of Wyoming's springs with worldwide thermal features are included. A discussion of geothermal energy resources, a guide for visitors, and an analysis of the flora of Wyoming's springs follow the spring inventory. The listing and analysis of Wyoming's thermal springs are arranged alphabetically by county. Tabulated data are given on elevation, ownership, access, water temperature, and flow rate. Each spring system is described and its history, general characteristics and uses, geology, hydrology, and chemistry are discussed. (MHR)

  4. Thermal Acoustic Fatigue Apparatus

    Data.gov (United States)

    Federal Laboratory Consortium — The Thermal Acoustic Fatigue Apparatus (TAFA) is a progressive wave tube test facility that is used to test structures for dynamic response and sonic fatigue due to...

  5. Thermal hyperbolic metamaterials.

    Science.gov (United States)

    Guo, Yu; Jacob, Zubin

    2013-06-17

    We explore the near-field radiative thermal energy transfer properties of hyperbolic metamaterials. The presence of unique electromagnetic states in a broad bandwidth leads to super-planckian thermal energy transfer between metamaterials separated by a nano-gap. We consider practical phonon-polaritonic metamaterials for thermal engineering in the mid-infrared range and show that the effect exists in spite of the losses, absorption and finite unit cell size. For thermophotovoltaic energy conversion applications requiring energy transfer in the near-infrared range we introduce high temperature hyperbolic metamaterials based on plasmonic materials with a high melting point. Our work paves the way for practical high temperature radiative thermal energy transfer applications of hyperbolic metamaterials.

  6. ThermalTracker Software

    Energy Technology Data Exchange (ETDEWEB)

    2016-08-10

    The software processes recorded thermal video and detects the flight tracks of birds and bats that passed through the camera's field of view. The output is a set of images that show complete flight tracks for any detections, with the direction of travel indicated and the thermal image of the animal delineated. A report of the descriptive features of each detected track is also output in the form of a comma-separated value text file.

  7. Thermal Anemometry Grid Sensor

    OpenAIRE

    Martin Arlit; Eckhard Schleicher; Uwe Hampel

    2017-01-01

    A novel thermal anemometry grid sensor was developed for the simultaneous measurement of cross-sectional temperature and axial velocity distribution in a fluid flow. The sensor consists of a set of platinum resistors arranged in a regular grid. Each platinum resistor allows the simultaneous measurement of fluid temperature via electrical resistance and flow velocity via constant voltage thermal anemometry. Cross-sectional measurement was enabled by applying a special multiplexing-excitation s...

  8. Thermal conveyance systems

    Energy Technology Data Exchange (ETDEWEB)

    Meador, J.T.

    1978-09-01

    The purpose of the evaluation is to characterize modern technology for long-distance, large-diameter, underground steam and high-temperature water (HTW) transport systems and for hot-water and chilled-water systems that distribute thermal energy within communities. Data on the status of existing systems have been compiled and compared with recommended design factors for fluid flow to aid in parameter selection for assessing performance in transporting and distributing thermal energy.

  9. Thermal properties examples

    OpenAIRE

    Bantle, Michael

    2017-01-01

    Thermal properties of selected organic products were investigated using novel DSC technique and methods of determination. The report includes determination of freezing temperatures, glass transition temperatures, amount of ice, and end of freezing point, heat capacity and thermal conductivity for selected cases. One part of the experimental work was devoted to investigate the difference between oils extracted from organic and conventional salmon. The main aim of the investigation was to u...

  10. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Siegel, Robert

    2016-01-01

    Further expanding on the changes made to the fifth edition, Thermal Radiation Heat Transfer, 6th Edition continues to highlight the relevance of thermal radiative transfer and focus on concepts that develop the radiative transfer equation (RTE). The book explains the fundamentals of radiative transfer, introduces the energy and radiative transfer equations, covers a variety of approaches used to gauge radiative heat exchange between different surfaces and structures, and provides solution techniques for solving the RTE.

  11. Art as Alterity in Education

    Science.gov (United States)

    Zhao, Guoping

    2014-01-01

    In education, art has often been perceived as entertainment and decoration and is the first subject to go when there are budget cuts or test-score pressures. Drawing on Emmanuel Lévinas's idea of the primacy of radical alterity that breaks the totality of our being, enables self-transformation and ethics, and ensures community as a totality…

  12. Epigenetic alterations in hematopoietic malignancies.

    Science.gov (United States)

    Chung, Young Rock; Schatoff, Emma; Abdel-Wahab, Omar

    2012-10-01

    Gene discovery efforts in patients with hematopoietic malignancies have brought to the forefront a series of mutations in genes thought to be involved in the epigenetic regulation of gene transcription. These mutations occur in genes known, or suspected, to play a role in modifying cytosine nucleotides on DNA and/or altering the state of histone modifications. Genes such as ASXL1, DNMT3A, EZH2, IDH1/2, MLL1, and TET2 all have been shown to be mutated and/or translocated in patients with myeloid malignancies. Intriguingly, many of the alterations affecting DNA cytosine modifications in myeloid malignancies (mutations in DNMT3A, IDH1/2, and TET2) have also been found in patients with T-cell lymphomas, and EZH2 mutations appear to be critical in T-cell acute lymphoblastic leukemia development as well. In addition, the discovery of frequent mutations in CREBBP, EP300, EZH2, and MLL2 in B-cell lymphomas suggests that epigenetic alterations play a critical role in lymphomagenesis. The purpose of this review is to present functional evidence of how alterations in these epigenetic modifiers promote hematopoietic transformation. The conclusions drawn from these data are valuable in understanding biological mechanisms and potential therapeutic targets.

  13. Battery Thermal Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, Matthew A [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-08

    The operating temperature is critical in achieving the right balance between performance, cost, and life for both Li-ion batteries and ultracapacitors. The chemistries of advanced energy-storage devices - such as lithium-based batteries - are very sensitive to operating temperature. High temperatures degrade batteries faster while low temperatures decrease their power and capacity, affecting vehicle range, performance, and cost. Understanding heat generation in battery systems - from the individual cells within a module, to the inter-connects between the cells, and across the entire battery system - is imperative for designing effective thermal-management systems and battery packs. At NREL, we have developed unique capabilities to measure the thermal properties of cells and evaluate thermal performance of battery packs (air or liquid cooled). We also use our electro-thermal finite element models to analyze the thermal performance of battery systems in order to aid battery developers with improved thermal designs. NREL's tools are used to meet the weight, life, cost, and volume goals set by the U.S. Department of Energy for electric drive vehicles.

  14. Thermal surveillance of active volcanoes. [infrared scanner recordings of thermal anomalies of Mt. Baker volcano

    Science.gov (United States)

    Friedman, J. D. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. By the end of 1973, aerial infrared scanner traverses for thermal anomaly recordings of all Cascade Range volcanoes were essentially completed. Amplitude level slices of the Mount Baker anomalies were completed and compiled at a scale of 1:24,000, thus producing, for the first time, an accurate map of the distribution and intensity of thermal activity on Mount Baker. The major thermal activity is concentrated within the crater south of the main summit and although it is characterized by intensive solfataric activity and warm ground, it is largely subglacial, causing the development of sizable glacier perforation features. The outgoing radiative flux from the east breach anomalies is sufficient to account for the volume of ice melted to form the glacier perforations. DCP station 6251 has been monitoring a thermally anomalous area on the north slope of Mount Baker. The present thermal activity of Mount Baker accounts for continuing hydrothermal alteration in the crater south of the main summit and recurrent debris avalanches from Sherman Peak on its south rim. The infrared anomalies mapped as part of the experiment SR 251 are considered the basic evidence of the subglacial heating which was the probable triggering mechanism of an avalanche down Boulder Glacier on August 20-21, 1973.

  15. Local Thermal Insulating Materials For Thermal Energy Storage ...

    African Journals Online (AJOL)

    Thermal insulation is one of the most important components of a thermal energy storage system. In this paper the thermal properties of selected potential local materials which can be used for high temperature insulation are presented. Thermal properties of seven different samples were measured. Samples consisted of: ...

  16. Effects of water and sawdust additives on thermal effusivity, thermal ...

    African Journals Online (AJOL)

    The effects of water and sawdust additives on the thermal effusivity (e), thermal conductivity (λ), and durability of cement-stabilized laterites were investigated. The thermal effusivity (e) and conductivity(λ) have direct influ-ence on heat transfer and thermal insulation in buildings, and the parameters were determined by hot ...

  17. Thermal carrying capacity for a thermally-sensitive species at the warmest edge of its range.

    Directory of Open Access Journals (Sweden)

    Daniel Ayllón

    Full Text Available Anthropogenic environmental change is causing unprecedented rates of population extirpation and altering the setting of range limits for many species. Significant population declines may occur however before any reduction in range is observed. Determining and modelling the factors driving population size and trends is consequently critical to predict trajectories of change and future extinction risk. We tracked during 12 years 51 populations of a cold-water fish species (brown trout Salmo trutta living along a temperature gradient at the warmest thermal edge of its range. We developed a carrying capacity model in which maximum population size is limited by physical habitat conditions and regulated through territoriality. We first tested whether population numbers were driven by carrying capacity dynamics and then targeted on establishing (1 the temperature thresholds beyond which population numbers switch from being physical habitat- to temperature-limited; and (2 the rate at which carrying capacity declines with temperature within limiting thermal ranges. Carrying capacity along with emergent density-dependent responses explained up to 76% of spatio-temporal density variability of juveniles and adults but only 50% of young-of-the-year's. By contrast, young-of-the-year trout were highly sensitive to thermal conditions, their performance declining with temperature at a higher rate than older life stages, and disruptions being triggered at lower temperature thresholds. Results suggest that limiting temperature effects were progressively stronger with increasing anthropogenic disturbance. There was however a critical threshold, matching the incipient thermal limit for survival, beyond which realized density was always below potential numbers irrespective of disturbance intensity. We additionally found a lower threshold, matching the thermal limit for feeding, beyond which even unaltered populations declined. We predict that most of our study

  18. Tunable Radiative Thermal Rectifiers : Toward Thermal Logical Circuits

    OpenAIRE

    Nefzaoui, Elyes; Ezzahri, Younès; Joulain, Karl; Drevillon, Jérémie

    2015-01-01

    International audience; Thermal rectification can be defined as an asymmetry in the heat flux when the temperature difference between two interacting thermal reservoirs is reversed. We present a thermal rectifier concept based on far-field radiative heat transfer. The device is composed of two opaque thermal baths 1 and 2 at temperatures T 1 and T 2 respectively and exchanging heat through thermal radiation. The two interacting bodies are made of spectrally selective photonic structures with ...

  19. Landsat and Thermal Infrared Imaging

    Science.gov (United States)

    Arvidson, Terry; Barsi, Julia; Jhabvala, Murzy; Reuter, Dennis

    2012-01-01

    The purpose of this chapter is to describe the collection of thermal images by Landsat sensors already on orbit and to introduce the new thermal sensor to be launched in 2013. The chapter describes the thematic mapper (TM) and enhanced thematic mapper plus (ETM+) sensors, the calibration of their thermal bands, and the design and prelaunch calibration of the new thermal infrared sensor (TIRS).

  20. The InSight Mars Lander and Its Effect on the Subsurface Thermal Environment

    Science.gov (United States)

    Siegler, Matthew A.; Smrekar, Suzanne E.; Grott, Matthias; Piqueux, Sylvain; Mueller, Nils; Williams, Jean-Pierre; Plesa, Ana-Catalina; Spohn, Tilman

    2017-10-01

    The 2018 InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) Mission has the mission goal of providing insitu data for the first measurement of the geothermal heat flow of Mars. The Heat Flow and Physical Properties Package (HP3) will take thermal conductivity and thermal gradient measurements to approximately 5 m depth. By necessity, this measurement will be made within a few meters of the lander. This means that thermal perturbations from the lander will modify local surface and subsurface temperature measurements. For HP3's sensitive thermal gradient measurements, this spacecraft influence will be important to model and parameterize. Here we present a basic 3D model of thermal effects of the lander on its surroundings. Though lander perturbations significantly alter subsurface temperatures, a successful thermal gradient measurement will be possible in all thermal conditions by proper (>3 m depth) placement of the heat flow probe.

  1. ASSESSING LONGITUDINAL THERMAL CONNECTIVITY ...

    Science.gov (United States)

    Water temperature is a key driver of ecological processes in aquatic environments and can influence biological connectivity among riverine habitats. Riverine fish and other mobile aquatic species often must navigate a variety of physical barriers such as dams and culverts. For Pacific salmon, warm water can also pose barriers to migration, but the presence of patches of cooler water within rivers can serve as important refuges and potentially as stepping stones at times of day when temperatures are elsewhere unsuitable along the migratory corridor. Rising water temperature associated with climate change has become a major conservation concern for freshwater species and poses challenges for natural resource managers who must consider multiple factors in addition to uncertainty in climate predictions. Thermal refuges can contribute to watershed-scale thermal resilience and are increasingly considered in water quality regulations; however, monitoring such refuges and effectively operationalizing the concept for management has proved difficult. We review what is known about use of thermal refuges by coldwater fishes in natural systems, and then we present two case study applications in which we characterize thermal patterns in rivers (e.g., the frequency, size, spacing, and location of thermal patches) and consider effects on salmon in a management context. In our first example, we illustrate methods for quantifying spatial heterogeneity in stream temperatures at bi

  2. Photodegradation of thermally modified wood.

    Science.gov (United States)

    Srinivas, Kavyashree; Pandey, Krishna K

    2012-12-05

    Natural wood, being biological material, undergoes rapid degradation by ultraviolet (UV) radiations and other environmental factors under outdoor exposure. In order to protect wood from such degradation, the chemical structure of wood is altered by chemical modification or heat treatment. In the present study, heat treated specimens of rubberwood (Hevea brasiliensis) were exposed to xenon light source in a weather-o-meter for different periods up to 300 h. Photostability of modified and unmodified wood was evaluated in terms of colour and chemical changes. Light coloured untreated wood became dark upon UV irradiation whereas, dark colour of heat treated wood lightened on UV exposure. CIE lightness parameter (L(*)) decreased for untreated wood whereas its value increased for heat treated wood upon irradiation. Other colour coordinates a(*) and b(*) increased with exposure duration for both untreated and heat treated wood. The overall colour change (ΔE(*)) increased for both untreated and heat treated wood. The Fourier Transform Infrared (FTIR) spectroscopic studies revealed severe lignin degradation of heat treated wood due to UV light exposure. Colour changes and FTIR measurements indicate that thermal modification of wood was ineffective in restricting light induced colour changes and photodegradation of wood polymers. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Buccal alterations in diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Negrato Carlos

    2010-01-01

    Full Text Available Abstract Long standing hyperglycaemia besides damaging the kidneys, eyes, nerves, blood vessels, heart, can also impair the function of the salivary glands leading to a reduction in the salivary flow. When salivary flow decreases, as a consequence of an acute hyperglycaemia, many buccal or oral alterations can occur such as: a increased concentration of mucin and glucose; b impaired production and/or action of many antimicrobial factors; c absence of a metalloprotein called gustin, that contains zinc and is responsible for the constant maturation of taste papillae; d bad taste; e oral candidiasis f increased cells exfoliation after contact, because of poor lubrication; g increased proliferation of pathogenic microorganisms; h coated tongue; i halitosis; and many others may occur as a consequence of chronic hyperglycaemia: a tongue alterations, generally a burning mouth; b periodontal disease; c white spots due to demineralization in the teeth; d caries; e delayed healing of wounds; f greater tendency to infections; g lichen planus; h mucosa ulcerations. Buccal alterations found in diabetic patients, although not specific of this disease, have its incidence and progression increased when an inadequate glycaemic control is present.

  4. Thermal stability of DNA with interstrand crosslinks.

    Science.gov (United States)

    Chang, Chun-Ling; Lando, Dmitri Y; Fridman, Alexander S; Hu, Chin-Kun

    2012-10-01

    Although many anticancer drugs exert their biological activity by forming DNA interstrand crosslinks (ICLs), the thermodynamics of biologically relevant long crosslinked DNAs has not been intensively studied in contrast to short duplexes. Here, we carry out computer modeling of the shift of melting temperature of long DNAs caused by ICLs taking into account crosslinking effect in itself and concomitant local alterations in the free energy (δG) of the helix-coil transition at sites of ICLs. Depending on δG, DNA interstrand crosslinks at per nucleotide concentration r = 0.05 can change the melting temperature by value from -17 to +47°C, and the influence weakly depends on DNA sequence and GC content. A change in melting temperature caused by introduction of interstrand crosslinking in modified DNA at sites of modifications also depends on δG and varies from 0 to +12°C. Comparison with experiment for the three platinum crosslinking compounds demonstrates utility of the theoretical method for understanding how crosslinking compounds can influence the melting behavior. On the basis of the method, interdependence of local distortions and crosslinking in itself was studied for thermal effect of ICLs. A method for evaluating the nature of the structural alteration that produces a change in thermal stability for short crosslinked DNA is also proposed. The methods can be used for comparative thermodynamic characterization of various DNA crosslinking agents. Copyright © 2012 Wiley Periodicals, Inc.

  5. Concepts in Thermal Physics

    CERN Document Server

    Blundell, Stephen J

    2006-01-01

    This modern introduction to thermal physics contains a step-by-step presentation of the key concepts. The text is copiously illustrated and each chapter contains several worked examples. - ;An understanding of thermal physics is crucial to much of modern physics, chemistry and engineering. This book provides a modern introduction to the main principles that are foundational to thermal physics, thermodynamics, and statistical mechanics. The key concepts are carefully presented in a clear way, and new ideas are illustrated with copious worked examples as well as a description of the historical background to their discovery. Applications are presented to subjects as. diverse as stellar astrophysics, information and communication theory, condensed matter physics, and climate change. Each chapter concludes with detailed exercises. -

  6. Highly Thermal Conductive Nanocomposites

    Science.gov (United States)

    Sun, Ya-Ping (Inventor); Connell, John W. (Inventor); Veca, Lucia Monica (Inventor)

    2017-01-01

    Disclosed are methods for forming carbon-based fillers as may be utilized in forming highly thermal conductive nanocomposite materials. Formation methods include treatment of an expanded graphite with an alcohol/water mixture followed by further exfoliation of the graphite to form extremely thin carbon nanosheets that are on the order of between about 2 and about 10 nanometers in thickness. Disclosed carbon nanosheets can be functionalized and/or can be incorporated in nanocomposites with extremely high thermal conductivities. Disclosed methods and materials can prove highly valuable in many technological applications including, for instance, in formation of heat management materials for protective clothing and as may be useful in space exploration or in others that require efficient yet light-weight and flexible thermal management solutions.

  7. Electrical and Thermal Conductivity

    Science.gov (United States)

    Ventura, Guglielmo; Perfetti, Mauro

    After a Sect. 1.1 devoted to electrical conductivity and a section that deals with magnetic and dielectric losses ( 1.2 ), this chapter explores the theory of thermal conduction in solids. The examined categories of solids are: metals Sect. 1.3.2 , Dielectrics Sects. 1.3.3 and 1.3.4 and Nanocomposites Sect. 1.3.5 . In Sect. 1.3.6 the problem of thermal and electrical contact between materials is considered because contact resistance occurring at conductor joints in magnets or other high power applications can lead to undesirable electrical losses. At low temperature, thermal contact is also critical in the mounting of temperature sensors, where bad contacts can lead to erroneous results, in particular when superconductivity phenomena are involved.

  8. Design without thermal bridges

    Directory of Open Access Journals (Sweden)

    Maltseva Irina

    2018-01-01

    Full Text Available The main focus of the article is on the quality design and implementation of the thermal insulation of buildings. Shells of buildings consist not only of conventional structures (wall, roof, ceiling, but also of edges, corners, joints and places of disruption of the outer thermal insulation shell integrity (due to through passage of pipelines, ventilation ducts and etc.. In all these places, heat losses are generally increased in comparison with conventional surfaces. Some of them are easily taken into account by calculation, using a special method proposed by the authors. Other thermal bridges due to unfavorable structural details can be avoided by observing the rules and recommendations that are classified and discussed in detail in this article.

  9. Thermal Anemometry Grid Sensor

    Directory of Open Access Journals (Sweden)

    Martin Arlit

    2017-07-01

    Full Text Available A novel thermal anemometry grid sensor was developed for the simultaneous measurement of cross-sectional temperature and axial velocity distribution in a fluid flow. The sensor consists of a set of platinum resistors arranged in a regular grid. Each platinum resistor allows the simultaneous measurement of fluid temperature via electrical resistance and flow velocity via constant voltage thermal anemometry. Cross-sectional measurement was enabled by applying a special multiplexing-excitation scheme. In this paper, we present the design and characterization of a prototypical sensor for measurements in a range of very low velocities.

  10. Thermal management of batteries

    Science.gov (United States)

    Gibbard, H. F.; Chen, C.-C.

    Control of the internal temperature during high rate discharge or charge can be a major design problem for large, high energy density battery systems. A systematic approach to the thermal management of such systems is described for different load profiles based on: thermodynamic calculations of internal heat generation; calorimetric measurements of heat flux; analytical and finite difference calculations of the internal temperature distribution; appropriate system designs for heat removal and temperature control. Examples are presented of thermal studies on large lead-acid batteries for electrical utility load levelling and nickel-zinc and lithium-iron sulphide batteries for electric vehicle propulsion.

  11. Thermal Anemometry Grid Sensor.

    Science.gov (United States)

    Arlit, Martin; Schleicher, Eckhard; Hampel, Uwe

    2017-07-19

    A novel thermal anemometry grid sensor was developed for the simultaneous measurement of cross-sectional temperature and axial velocity distribution in a fluid flow. The sensor consists of a set of platinum resistors arranged in a regular grid. Each platinum resistor allows the simultaneous measurement of fluid temperature via electrical resistance and flow velocity via constant voltage thermal anemometry. Cross-sectional measurement was enabled by applying a special multiplexing-excitation scheme. In this paper, we present the design and characterization of a prototypical sensor for measurements in a range of very low velocities.

  12. No Thermalization without Correlations

    Science.gov (United States)

    Zhdanov, Dmitry V.; Bondar, Denys I.; Seideman, Tamar

    2017-10-01

    The proof of the long-standing conjecture is presented that Markovian quantum master equations are at odds with quantum thermodynamics under conventional assumptions of fluctuation-dissipation theorems (implying a translation invariant dissipation). Specifically, except for identified systems, persistent system-bath correlations of at least one kind, spatial or temporal, are obligatory for thermalization. A systematic procedure is proposed to construct translation invariant bath models producing steady states that well approximate thermal states. A quantum optical scheme for the laboratory assessment of the developed procedure is outlined.

  13. Thermal Inactivation of Viruses

    Science.gov (United States)

    1977-10-01

    S) VIKU3FS THERMAL RESISTANCE FOODS FLUIDS FOOD PROCESSING FOOD PRESERVATION CONTAMINATION HEAT VIRAL NUCLEIC ACIDS ao’.AjUsTNACT (Conilnum...an rm**— •**» It nmc +nmy m>d Id+atttr by M«o* fmbm) A review of the literature pertaining to thermal inactivation of virus in fluid media» fluid...vacuum packaged in cans or in flexible pouches , frozen to ca. -40 C, and irradiated within a temperature range of -40 C to -8 C to obtain the

  14. Thermal Network Modelling Handbook

    Science.gov (United States)

    1972-01-01

    Thermal mathematical modelling is discussed in detail. A three-fold purpose was established: (1) to acquaint the new user with the terminology and concepts used in thermal mathematical modelling, (2) to present the more experienced and occasional user with quick formulas and methods for solving everyday problems, coupled with study cases which lend insight into the relationships that exist among the various solution techniques and parameters, and (3) to begin to catalog in an orderly fashion the common formulas which may be applied to automated conversational language techniques.

  15. Thermal management for LED applications

    CERN Document Server

    Poppe, András

    2014-01-01

    Thermal Management for LED Applications provides state-of-the-art information on recent developments in thermal management as it relates to LEDs and LED-based systems and their applications. Coverage begins with an overview of the basics of thermal management including thermal design for LEDs, thermal characterization and testing of LEDs, and issues related to failure mechanisms and reliability and performance in harsh environments. Advances and recent developments in thermal management round out the book with discussions on advances in TIMs (thermal interface materials) for LED applications, advances in forced convection cooling of LEDs, and advances in heat sinks for LED assemblies. This book also: Presents a comprehensive overview of the basics of thermal management as it relates to LEDs and LED-based systems Discusses both design and thermal management considerations when manufacturing LEDs and LED-based systems Covers reliability and performance of LEDs in harsh environments Has a hands-on applications a...

  16. Shape memory thermal conduction switch

    Science.gov (United States)

    Vaidyanathan, Rajan (Inventor); Krishnan, Vinu (Inventor); Notardonato, William U. (Inventor)

    2010-01-01

    A thermal conduction switch includes a thermally-conductive first member having a first thermal contacting structure for securing the first member as a stationary member to a thermally regulated body or a body requiring thermal regulation. A movable thermally-conductive second member has a second thermal contacting surface. A thermally conductive coupler is interposed between the first member and the second member for thermally coupling the first member to the second member. At least one control spring is coupled between the first member and the second member. The control spring includes a NiTiFe comprising shape memory (SM) material that provides a phase change temperature <273 K, a transformation range <40 K, and a hysteresis of <10 K. A bias spring is between the first member and the second member. At the phase change the switch provides a distance change (displacement) between first and second member by at least 1 mm, such as 2 to 4 mm.

  17. Anisotropic Thermal Diffusivities of Plasma-Sprayed Thermal Barrier Coatings

    Science.gov (United States)

    Akoshima, Megumi; Takahashi, Satoru

    2017-09-01

    Thermal barrier coatings (TBCs) are used to shield the blades of gas turbines from heat and wear. There is a pressing need to evaluate the thermal conductivity of TBCs in the thermal design of advanced gas turbines with high energy efficiency. These TBCs consist of a ceramic-based top coat and a bond coat on a superalloy substrate. Usually, the focus is on the thermal conductivity in the thickness direction of the TBC because heat tends to diffuse from the surface of the top coat to the substrate. However, the in-plane thermal conductivity is also important in the thermal design of gas turbines because the temperature distribution within the turbine cannot be ignored. Accordingly, a method is developed in this study for measuring the in-plane thermal diffusivity of the top coat. Yttria-stabilized zirconia top coats are prepared by thermal spraying under different conditions. The in-plane and cross-plane thermal diffusivities of the top coats are measured by the flash method to investigate the anisotropy of thermal conduction in a TBC. It is found that the in-plane thermal diffusivity is higher than the cross-plane one for each top coat and that the top coats have significantly anisotropic thermal diffusivity. The cross-sectional and in-plane microstructures of the top coats are observed, from which their porosities are evaluated. The thermal diffusivity and its anisotropy are discussed in detail in relation to microstructure and porosity.

  18. Active thermal isolation for temperature responsive sensors

    Science.gov (United States)

    Martinson, Scott D. (Inventor); Gray, David L. (Inventor); Carraway, Debra L. (Inventor); Reda, Daniel C. (Inventor)

    1994-01-01

    The detection of flow transition between laminar and turbulent flow and of shear stress or skin friction of airfoils is important in basic research for validation of airfoil theory and design. These values are conventionally measured using hot film nickel sensors deposited on a polyimide substrate. The substrate electrically insulates the sensor and underlying airfoil but is prevented from thermally isolating the sensor by thickness constraints necessary to avoid flow contamination. Proposed heating of the model surface is difficult to control, requires significant energy expenditures, and may alter the basic flow state of the airfoil. A temperature responsive sensor is located in the airflow over the specified surface of a body and is maintained at a constant temperature. An active thermal isolator is located between this temperature responsive sensor and the specific surface of the body. The total thickness of the isolator and sensor avoid any contamination of the flow. The temperature of this isolator is controlled to reduce conductive heat flow from the temperature responsive sensor to the body. This temperature control includes (1) operating the isolator at the same temperature as the constant temperature of the sensor; and (2) establishing a fixed boundary temperature which is either less than or equal to, or slightly greater than the sensor constant temperature. The present invention accordingly thermally isolates a temperature responsive sensor in an energy efficient, controllable manner while avoiding any contamination of the flow.

  19. THERMAL INSULATION SYSTEMS

    Science.gov (United States)

    Augustynowicz, Stanislaw D. (Inventor); Fesmire, James E. (Inventor)

    2005-01-01

    Thermal insulation systems and with methods of their production. The thermal insulation systems incorporate at least one reflection layer and at least one spacer layer in an alternating pattern. Each spacer layer includes a fill layer and a carrier layer. The fill layer may be separate from the carrier layer, or it may be a part of the carrier layer, i.e., mechanically injected into the carrier layer or chemically formed in the carrier layer. Fill layers contain a powder having a high surface area and low bulk density. Movement of powder within a fill layer is restricted by electrostatic effects with the reflection layer combined with the presence of a carrier layer, or by containing the powder in the carrier layer. The powder in the spacer layer may be compressed from its bulk density. The thermal insulation systems may further contain an outer casing. Thermal insulation systems may further include strips and seams to form a matrix of sections. Such sections serve to limit loss of powder from a fill layer to a single section and reduce heat losses along the reflection layer.

  20. Spacecraft thermal modelling

    Science.gov (United States)

    Chin, J. H.; Panczak, T. D.; Fried, L.

    1992-09-01

    Thermal modeling of spacecraft requires approaches which can handle dominant radiative heat transfers and many special thermal control components. Present network-type thermal analyzers allow simulation, especially for components with rectangular geometries, but at the expense of considerable awkwardness and much error-prone manual input. The user interfaces for pre- and postprocessing for these analyzers are also very deficient. Finite element thermal analyzers solve some of the analytical difficulties, but are not widely used because they lack the flexibility to simulate special operations. The Galerkin finite element method (GFEM) distributes the contributions within an element to the element nodal points. The assembly of the contributions from all elements yields a system of energy balance equations for the nodal points of the system. Monte Carlo raytracing, in conjunction with a GFEM energy distribution to element nodal points, yields a procedure of consistent nonisothermal surface radiation exchange. This procedure reduces a source of simulation error caused by nonuniform element illumination and shading. Orbital heating, fluid flow and special analysis features are discussed. The main analysis program is interfaced to the preprocessing and postprocessing modules.

  1. Thermal inactivation of microorganisms

    NARCIS (Netherlands)

    Smelt, J.P.P.M.; Brul, S.

    2014-01-01

    This paper serves as an overview of various aspects of thermal processing. Heat processing of foods has a long history and is still one of the most important preservation methods. To guarantee microbiological safety and stability, large safety margins are often applied in traditional heat processes.

  2. Thermal decomposition of hemicelluloses

    OpenAIRE

    Werner, Kajsa; Pommer, Linda; Broström, Markus

    2014-01-01

    Decomposition modeling of biomass often uses commercially available xylan as model compound representing hemicelluloses, not taking in account the heterogeneous nature of that group of carbohydrates. In this study, the thermal decomposition behavior of seven different hemicelluloses (beta-glucan, arabinogalactan, arabinoxylan, galactomannan, glucomannan, xyloglucan, and xylan) were investigated in inert atmosphere using (i) thermogravimetric analysis coupled to Fourier transform infrared spec...

  3. Thermal Cameras and Applications

    DEFF Research Database (Denmark)

    Gade, Rikke; Moeslund, Thomas B.

    2014-01-01

    Thermal cameras are passive sensors that capture the infrared radiation emitted by all objects with a temperature above absolute zero. This type of camera was originally developed as a surveillance and night vision tool for the military, but recently the price has dropped, significantly opening up...

  4. Solar Thermal Power.

    Science.gov (United States)

    McDaniels, David K.

    The different approaches to the generation of power from solar energy may be roughly divided into five categories: distributed collectors; central receivers; biomass; ocean thermal energy conversion; and photovoltaic devices. The first approach (distributed collectors) is the subject of this module. The material presented is designed to…

  5. Combining thermal comfort models

    Energy Technology Data Exchange (ETDEWEB)

    Yigit, A.

    1999-07-01

    Two models commonly used in thermal comfort studies were combined to develop a two-dimensional computer model that estimates the resistance to dry and evaporative heat transfer for a clothing system from fabric resistance data, fabric thickness data, and information concerning the amount of body surface area covered by different fabric layers and the amount of air trapped between fabric layers. Five different clothing ensembles with different total thermal insulation and very different distributions of the insulation on the body were simulated with 16 sedentary subjects. This paper first evaluates total thermal insulation predictions from the Fanger steady-state model and then uses these data in the Gagge two-compartment (or two-node) model. The combined model uses the transient heat balance of each segment and the whole body. It estimates total insulation value and then uses this value to calculate transient temperature and wettedness. By application of the combined model, predictions of human responses to a wide range of thermal conditions are compared with the responses of human subjects as described in reports of laboratory experiments. Possible reasons for discrepancies between the observed data and predictions of the model are briefly discussed.

  6. Thermal Reactor Safety

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    Information is presented concerning fire risk and protection; transient thermal-hydraulic analysis and experiments; class 9 accidents and containment; diagnostics and in-service inspection; risk and cost comparison of alternative electric energy sources; fuel behavior and experiments on core cooling in LOCAs; reactor event reporting analysis; equipment qualification; post facts analysis of the TMI-2 accident; and computational methods.

  7. Solar thermal financing guidebook

    Energy Technology Data Exchange (ETDEWEB)

    Williams, T.A.; Cole, R.J.; Brown, D.R.; Dirks, J.A.; Edelhertz, H.; Holmlund, I.; Malhotra, S.; Smith, S.A.; Sommers, P.; Willke, T.L.

    1983-05-01

    This guidebook contains information on alternative financing methods that could be used to develop solar thermal systems. The financing arrangements discussed include several lease alternatives, joint venture financing, R and D partnerships, industrial revenue bonds, and ordinary sales. In many situations, alternative financing arrangements can significantly enhance the economic attractiveness of solar thermal investments by providing a means to efficiently allocate elements of risk, return on investment, required capital investment, and tax benefits. A net present value approach is an appropriate method that can be used to investigate the economic attractiveness of alternative financing methods. Although other methods are applicable, the net present value approach has advantages of accounting for the time value of money, yielding a single valued solution to the financial analysis, focusing attention on the opportunity cost of capital, and being a commonly understood concept that is relatively simple to apply. A personal computer model for quickly assessing the present value of investments in solar thermal plants with alternative financing methods is presented in this guidebook. General types of financing arrangements that may be desirable for an individual can be chosen based on an assessment of his goals in investing in solar thermal systems and knowledge of the individual's tax situation. Once general financing arrangements have been selected, a screening analysis can quickly determine if the solar investment is worthy of detailed study.

  8. Acid Sulfate Alteration on Mars

    Science.gov (United States)

    Ming, D. W.; Morris, R. V.

    2016-01-01

    A variety of mineralogical and geochemical indicators for aqueous alteration on Mars have been identified by a combination of surface and orbital robotic missions, telescopic observations, characterization of Martian meteorites, and laboratory and terrestrial analog studies. Acid sulfate alteration has been identified at all three landing sites visited by NASA rover missions (Spirit, Opportunity, and Curiosity). Spirit landed in Gusev crater in 2004 and discovered Fe-sulfates and materials that have been extensively leached by acid sulfate solutions. Opportunity landing on the plains of Meridiani Planum also in 2004 where the rover encountered large abundances of jarosite and hematite in sedimentary rocks. Curiosity landed in Gale crater in 2012 and has characterized fluvial, deltaic, and lacustrine sediments. Jarosite and hematite were discovered in some of the lacustrine sediments. The high elemental abundance of sulfur in surface materials is obvious evidence that sulfate has played a major role in aqueous processes at all landing sites on Mars. The sulfate-rich outcrop at Meridiani Planum has an SO3 content of up to 25 wt.%. The interiors of rocks and outcrops on the Columbia Hills within Gusev crater have up to 8 wt.% SO3. Soils at both sites generally have between 5 to 14 wt.% SO3, and several soils in Gusev crater contain around 30 wt.% SO3. After normalization of major element compositions to a SO3-free basis, the bulk compositions of these materials are basaltic, with a few exceptions in Gusev crater and in lacustrine mudstones in Gale crater. These observations suggest that materials encountered by the rovers were derived from basaltic precursors by acid sulfate alteration under nearly isochemical conditions (i.e., minimal leaching). There are several cases, however, where acid sulfate alteration minerals (jarosite and hematite) formed in open hydrologic systems, e.g., in Gale crater lacustrine mudstones. Several hypotheses have been suggested for the

  9. Thermal Testing Measurements Report

    Energy Technology Data Exchange (ETDEWEB)

    R. Wagner

    2002-09-26

    The purpose of the Thermal Testing Measurements Report (Scientific Analysis Report) is to document, in one report, the comprehensive set of measurements taken within the Yucca Mountain Project Thermal Testing Program since its inception in 1996. Currently, the testing performed and measurements collected are either scattered in many level 3 and level 4 milestone reports or, in the case of the ongoing Drift Scale Test, mostly documented in eight informal progress reports. Documentation in existing reports is uneven in level of detail and quality. Furthermore, while all the data collected within the Yucca Mountain Site Characterization Project (YMP) Thermal Testing Program have been submitted periodically to the Technical Data Management System (TDMS), the data structure--several incremental submittals, and documentation formats--are such that the data are often not user-friendly except to those who acquired and processed the data. The documentation in this report is intended to make data collected within the YMP Thermal Testing Program readily usable to end users, such as those representing the Performance Assessment Project, Repository Design Project, and Engineered Systems Sub-Project. Since either detailed level 3 and level 4 reports exist or the measurements are straightforward, only brief discussions are provided for each data set. These brief discussions for different data sets are intended to impart a clear sense of applicability of data, so that they will be used properly within the context of measurement uncertainty. This approach also keeps this report to a manageable size, an important consideration because the report encompasses nearly all measurements for three long-term thermal tests. As appropriate, thermal testing data currently residing in the TDMS have been reorganized and reformatted from cumbersome, user-unfriendly Input-Data Tracking Numbers (DTNs) into a new set of Output-DTNs. These Output-DTNs provide a readily usable data structure

  10. Nicotinic acetylcholine receptor gene expression is altered in burn patients.

    Science.gov (United States)

    Osta, Walid A; El-Osta, Mohamed A; Pezhman, Eric A; Raad, Robert A; Ferguson, Kris; McKelvey, George M; Marsh, Harold M; White, Michael; Perov, Samuel

    2010-05-01

    Burn patients have been observed to be more susceptible to the hyperkalemic effect of the depolarizing muscle relaxant succinylcholine. Changes in nicotinic acetylcholine receptor (nAChR) subunit composition may alter electrophysiologic, pharmacologic, and metabolic characteristics of the receptor inducing hyperkalemia on exposure to succinylcholine. No studies have been performed that show the upregulation and/or alteration of nAChR subunit composition in human burn patients. The scarcity of studies performed on humans with burn injury is mainly attributable to the technical and ethical difficulties in obtaining muscle biopsies at different time frames of illness in these acutely injured patients. nAChRs are expressed in oral keratinocytes and are upregulated or altered in smokers. However, no studies have addressed the expression of nAChRs in the oral mucosa of burn patients. Buccal mucosal scrapings were collected from 9 burn patients and 6 control nonburn surgical intensive care unit patients. For burn and control patients, tissues were collected upon presentation (time: 0 hour) and at time points 12, 24, and 48 hours, 1 week, and 2 weeks. Gene expression of the nAChR subunits alpha1, alpha7, gamma, and epsilon were performed using real-time reverse transcriptase polymerase chain reaction. alpha7 and gamma nAChR genes were significantly upregulated in burn patients, whereas alpha1 and epsilon nAChR genes were minimally affected, showing no significant changes over time. Over the 2 weeks of measurement, an upregulation of the alpha7 and gamma genes occurred in both burn and control patients; however, the proportion of alpha7 and gamma subunit increases was significantly higher in burn patients than in control surgical intensive care unit patients. The relationship between the thermal injury and the observed alteration in gene expression suggests a possible cause/effect relationship. This effect was observed at a site not affected by the burn injury and in

  11. Colloidal Thermal Fluids

    Science.gov (United States)

    Lotzadeh, Saba

    In this dissertation, a reversible system with a well controlled degree of particle aggregation was developed. By surface modification of colloidal silica with aminosilanes, interactions among the particles were tuned in a controlled way to produce stable sized clusters at different pH values ranges from well-disposed to a colloidal gel. N-[3-(trimethoxysilyl)propyl]ethylenediamine (TMPE) monolayer on particle surface not only removes all the reactive sites to prevent chemical aggregation, also provides steric stabilization in the absence of any repulsion. After surface modification, electrokinetic behavior of silica particles were changed to that of amino groups, positive in acidic pH and neutral at basic pH values. By tuning the pH, the balance between electrostatic repulsion and hydrophobic interactions was reversibly controlled. As a result, clusters with different sizes were developed. The effect of clustering on the thermal conductivity of colloidal dispersions was quantified using silane-treated silica, a system engineered to exhibit reversible clustering under well-controlled conditions. Thermal conductivity of this system was measured by transient hot wire, the standard method of thermal conductivity measurements in liquids. We show that the thermal conductivity increases monotonically with cluster size and spans the entire range between the two limits of Maxwell's theory. The results, corroborated by numerical simulation, demonstrate that large increases of the thermal conductivity of colloidal dispersions are possible, yet fully within the predictions of classical theory. Numerical calculations were performed to evaluate the importance of structural properties of particles/aggregates on thermal conduction in colloidal particles. Thermal conductivity of non-spherical particles including hollow particles, cubic particles and rods was studied using a Monte Carlo algorithm. We show that anisotropic shapes, increase conductivity above that of isotropic

  12. Spacecraft Thermal Management

    Science.gov (United States)

    Hurlbert, Kathryn Miller

    2009-01-01

    In the 21st century, the National Aeronautics and Space Administration (NASA), the Russian Federal Space Agency, the National Space Agency of Ukraine, the China National Space Administration, and many other organizations representing spacefaring nations shall continue or newly implement robust space programs. Additionally, business corporations are pursuing commercialization of space for enabling space tourism and capital business ventures. Future space missions are likely to include orbiting satellites, orbiting platforms, space stations, interplanetary vehicles, planetary surface missions, and planetary research probes. Many of these missions will include humans to conduct research for scientific and terrestrial benefits and for space tourism, and this century will therefore establish a permanent human presence beyond Earth s confines. Other missions will not include humans, but will be autonomous (e.g., satellites, robotic exploration), and will also serve to support the goals of exploring space and providing benefits to Earth s populace. This section focuses on thermal management systems for human space exploration, although the guiding principles can be applied to unmanned space vehicles as well. All spacecraft require a thermal management system to maintain a tolerable thermal environment for the spacecraft crew and/or equipment. The requirements for human rating and the specified controlled temperature range (approximately 275 K - 310 K) for crewed spacecraft are unique, and key design criteria stem from overall vehicle and operational/programatic considerations. These criteria include high reliability, low mass, minimal power requirements, low development and operational costs, and high confidence for mission success and safety. This section describes the four major subsystems for crewed spacecraft thermal management systems, and design considerations for each. Additionally, some examples of specialized or advanced thermal system technologies are presented

  13. Hydrothermal alteration in the Baca Geothermal System, Redondo Dome, Valles Caldera, New Mexico

    Science.gov (United States)

    Hulen, Jeffrey B.; Nielson, Dennis L.

    1986-02-01

    Thermal fluids circulating in the active hydrothermal system of the resurgent Redondo dome of the Valles caldera have interacted with their diverse host rocks to produce well-zoned alteration assemblages, which not only help locate permeable fluid channels but also provide insight into the system's thermal history. The alteration shows that fluid flow has been confined principally to steeply dipping normal faults and subsidiary fractures as well as thin stratigraphic aquifers. Permeability along many of these channels has been reduced or locally eliminated by hydrothermal self-sealing. Alteration from the surface through the base of the Miocene Paliza Canyon Formation is of three distinctive types: argillic, propylitic, and phyllic. Argillic alteration forms a blanket above the deep water table in formerly permeable nonwelded tuffs. Beneath the argillic zone, pervasive propylitic alteration is weakly developed in felsic host rocks but locally intense in deep intermediate composition volcanics. Strong phyllic alteration is commonly but not invariably associated with major active thermal fluid channels. Phyllic zones yielding no fluid were clearly once permeable but now are hydrothermally sealed. High-temperature alteration phases at Baca are presently found at much lower temperatures. We suggest either that isotherms have collapsed due to gradual cooling of the system, that they have retreated without overall heat loss due to uplift of the Redondo dome, that the system has shifted laterally, or that it has contracted due to a drop in the water table. The deepest Well (B-12, 3423 m) in the dome may have penetrated through the base of the active hydrothermal system. Below a depth of 2440 m in this well, hydrothermal veining largely disappears, and the rocks resemble those developed by isochemical thermal metamorphism. The transition is reflected by temperature logs, which show a conductive thermal gradient below 2440 m. This depth may mark the dome's neutral plane

  14. Sensorimotor training alters action understanding.

    Science.gov (United States)

    Catmur, Caroline; Thompson, Emma L; Bairaktari, Orianna; Lind, Frida; Bird, Geoffrey

    2017-11-02

    The discovery of 'mirror' neurons stimulated intense interest in the role of motor processes in social interaction. A popular assumption is that observation-related motor activation, exemplified by mirror neurons' matching properties, evolved to subserve the 'understanding' of others' actions. Alternatively, such motor activation may result from sensorimotor learning. Sensorimotor training alters observation-related motor activation, but studies demonstrating training-dependent changes in motor activation have not addressed the functional role of such activation. We therefore tested whether sensorimotor learning alters action understanding. Participants completed an action understanding task, judging the weight of boxes lifted by another person, before and after 'counter-mirror' sensorimotor training. During this training they lifted heavy boxes while observing light boxes being lifted, and vice-versa. Compared to a control group, this training significantly reduced participants' action understanding ability. Performance on a duration judgement task was unaffected by training. These data suggest the ability to understand others' actions results from sensorimotor learning. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Circadian Disorganization Alters Intestinal Microbiota

    Science.gov (United States)

    Voigt, Robin M.; Forsyth, Christopher B.; Green, Stefan J.; Mutlu, Ece; Engen, Phillip; Vitaterna, Martha H.; Turek, Fred W.; Keshavarzian, Ali

    2014-01-01

    Intestinal dysbiosis and circadian rhythm disruption are associated with similar diseases including obesity, metabolic syndrome, and inflammatory bowel disease. Despite the overlap, the potential relationship between circadian disorganization and dysbiosis is unknown; thus, in the present study, a model of chronic circadian disruption was used to determine the impact on the intestinal microbiome. Male C57BL/6J mice underwent once weekly phase reversals of the light:dark cycle (i.e., circadian rhythm disrupted mice) to determine the impact of circadian rhythm disruption on the intestinal microbiome and were fed either standard chow or a high-fat, high-sugar diet to determine how diet influences circadian disruption-induced effects on the microbiome. Weekly phase reversals of the light:dark (LD) cycle did not alter the microbiome in mice fed standard chow; however, mice fed a high-fat, high-sugar diet in conjunction with phase shifts in the light:dark cycle had significantly altered microbiota. While it is yet to be established if some of the adverse effects associated with circadian disorganization in humans (e.g., shift workers, travelers moving across time zones, and in individuals with social jet lag) are mediated by dysbiosis, the current study demonstrates that circadian disorganization can impact the intestinal microbiota which may have implications for inflammatory diseases. PMID:24848969

  16. [Organ alterations due to aging].

    Science.gov (United States)

    Wieczorowska-Tobis, Katarzyna

    2008-01-01

    Aging defined as progressive organ dysfunction which makes keeping homeostasis more difficult starts at the age of 30-40. However, due to difficulties with the distinction between aging and disease processes, changes previously believed to be caused by aging are often recognized as the effect of pathologies when new data is presented. According to current knowledge, cardio-vascular aging includes decreased elasticity of main arteries, decreased ability of left ventricule to relaxate, diminished function of sino-atrial node and decreased effect of beta-adrenergic stimulation. Aging in the respiratory system is attributed to increased size of alveoli and alveolar ducts (which easier collapse), a decrease in the gase exchange area, a decrease in respiratory volumes (both static and dynamic) and a severe decrease in maximal oxygen consumption. In aging kidneys both renal blood flow and glomerular filtration are decreased. As the result of tubular alterations the kidney ability to conserve and dilute urine, and its capability to regulate the pH and serum sodium level diminish. Less dramatic changes are seen in the gastrointestinal tract. According to available data, high prevalence of gastric atrophy and hypochlorhydria are a consequence of Helicobacter pylori infection. Also, constipation is attributed much more to sedative life style and diet than to aging itself. In summary, none of the presented alterations is severe enough to cause the disease, but all of them increase the risk of pathology and thus pave the way for the disease even in healthy elderly subjects.

  17. Network and guest dependent thermal stability and thermal ...

    Indian Academy of Sciences (India)

    after the guest loss.32,64–66 Previously, lower thermal expansion due to low guest content have been shown only in the case of metal-organic frameworks. Thermal vibration of the guest molecules along the open channel axis does not cause expansion in the host network. This could be another reason for lower thermal ...

  18. Quantum thermal rectification to design thermal diodes and transistors

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-01

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

  19. Local Thermal Insulating Materials For Thermal Energy Storage

    African Journals Online (AJOL)

    Unknown User

    1. Introduction. It is necessary to use thermal insulating materials around thermal energy storage systems to minimize heat losses from the systems [1]. There are varieties of insulating materials which come in various forms like loose fill, rigid boards, pipe and foam. The thermal insulation is provided by embedding insulation ...

  20. Thermal Pyrolytic Graphite Enhanced Components

    Science.gov (United States)

    Hardesty, Robert E. (Inventor)

    2015-01-01

    A thermally conductive composite material, a thermal transfer device made of the material, and a method for making the material are disclosed. Apertures or depressions are formed in aluminum or aluminum alloy. Plugs are formed of thermal pyrolytic graphite. An amount of silicon sufficient for liquid interface diffusion bonding is applied, for example by vapor deposition or use of aluminum silicon alloy foil. The plugs are inserted in the apertures or depressions. Bonding energy is applied, for example by applying pressure and heat using a hot isostatic press. The thermal pyrolytic graphite, aluminum or aluminum alloy and silicon form a eutectic alloy. As a result, the plugs are bonded into the apertures or depressions. The composite material can be machined to produce finished devices such as the thermal transfer device. Thermally conductive planes of the thermal pyrolytic graphite plugs may be aligned in parallel to present a thermal conduction path.

  1. Thermally Actuated Hydraulic Pumps

    Science.gov (United States)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research

  2. Thermal conductivity of porous structures

    Science.gov (United States)

    Braginsky, L.; Shklover, V.; Witz, G.; Bossmann, H.-P.

    2007-03-01

    Thermal conductivity of porous media is considered. The model permits regular power-series expansion of the expression for thermal conductivity as a function of porosity. The coefficients of the expansion depend on two-site correlation function of local thermal conductivities, which can be calculated from the microscopy image of the structure. Thermal conductivities of some model two-dimensional structures as well as a real porous yttria-stabilized zirconia film are calculated and discussed.

  3. Thermal shock induced oxidation of beryllium

    Science.gov (United States)

    Spilker, B.; Linke, J.; Pintsuk, G.; Wirtz, M.

    2017-12-01

    Beryllium has been chosen as a plasma facing material for the first wall of the experimental fusion reactor ITER, mainly because of its low atomic number and oxygen getter capabilities, which are favorable for a high plasma performance. While the steady state operational temperature of 250 °C has no deteriorating effect on the beryllium surface, transient plasma events can deposit power densities of up to 1 GW m‑2 on the beryllium armor tiles. Previous research has shown that the oxidation of beryllium can occur under these thermal shock events. In the present study, S-65 grade beryllium specimens were exposed to 100 thermal shocks with an absorbed power density of 0.6 GW m‑2 and a pulse duration of 1 ms, leading to a peak surface temperature of ∼800 °C. The induced surface morphology changes were compared to a steady state heated specimen at the same surface temperature with a holding time of 150 s. As a result, a pitting structure with an average pit diameter of ∼0.45 μm was observed on the thermal shock loaded surface, which was caused by beryllium oxide grain nucleation and subsequent erosion of the weakly bound beryllium oxide particles. In contrast, the steady state heated surface exhibited a more homogeneous beryllium oxide layer featuring small pits with diameters of tens of nm and showed the beryllium oxide grain nucleation in a beginning stage. The experiment demonstrated that thermal shock loading conditions can significantly accelerate the beryllium oxide grain nucleation. The resulting surface morphology change can potentially alter the fusion application relevant erosion, absorption, and retention characteristics of beryllium.

  4. Oncogene alterations in endometrial carcinosarcomas.

    Science.gov (United States)

    Biscuola, Michele; Van de Vijver, Koen; Castilla, María Ángeles; Romero-Pérez, Laura; López-García, María Ángeles; Díaz-Martín, Juan; Matias-Guiu, Xavier; Oliva, Esther; Palacios Calvo, José

    2013-05-01

    Endometrial carcinosarcomas are aggressive neoplasias composed of high-grade carcinomatous and sarcomatous elements. The pathogenesis and specific genetic alterations underlying these tumors are still not well known. We analyzed alterations in oncogenes involved in the pathogenesis of endometrial carcinomas that might represent predictive markers for specific therapies. Immunohistochemistry for HER2 (tyrosine kinase-type cell surface receptor HER2) and c-KIT (tyrosine-protein kinase Kit) and fluorescence in situ hybridization for EGFR (epidermal growth factor receptor) and ALK (anaplastic lymphoma receptor tyrosine kinase) were carried out for 76 endometrial carcinosarcoma samples on sequential tissue microarray sections. Analysis of 238 mutations across 19 common oncogenes was performed on 34 samples using the Sequenom OncoCarta Panel (Sequenom, Hamburg, Germany). We observed EGFR, HER2, and c-KIT expression in 71%, 1.5%, and 2.7% of tumors, respectively. EGFR amplification was detected in 11 of 76 endometrial carcinosarcomas (14.5%). Four samples showed both amplification and aneuploidy (5.2%). ALK amplification together with chromosome 2 polysomy was found in 1.3% of endometrial carcinosarcomas. In total, 23 mutations in 9 different oncogenes were detected in 15 (44.1%) of 34 endometrial carcinosarcomas. Five endometrial carcinosarcomas (14.7%) had 2 or more mutations. Eleven tumors (32.3%) had mutations affecting the PI3K (phosphoinositide-3-kinase)/AKT (v-akt murine thymoma viral oncogene homolog 1) (6 mutations in PIK3CA (PI3K catalytic alpha polypeptide) and 1 in AKT) and/or RAS/BRAF (serine/threonine-protein kinase B-raf) pathway (3 KRAS [kirsten RAS oncogene homolog], 2 NRAS [neuroblastoma RAS viral oncogene homolog], and 1 BRAF). Mutations in PDGFRA (platelet-derived growth factor receptor, alpha polypeptide) and/or KIT were found in 5 endometrial carcinosarcomas (14.7%). Finally, we found mutations in MET (met proto-oncogene [hepatocyte growth factor

  5. Quantification of Thermal Lensing Using an Artificial Eye

    Science.gov (United States)

    2013-01-01

    was very sensitive to even the smallest temperature change. Surprisingly, the power level did not influence the time to bloom for each case; however...concluded the strength of the thermal lens is fully capable of significantly altering visual performance without damaging the eye. In the natural world , the...2012. [9] E. F. Maher. Transmission and absorption coefficients for the ocular media of the rhesus monkey . USAF School of Aerospace Medicine, TX, USA

  6. Thermal comfort: research and practice

    NARCIS (Netherlands)

    Mitja Mazej; Jan Hensen; Ir. Joost van Hoof

    2010-01-01

    Thermal comfort -the state of mind, which expresses satisfaction with the thermal environment- is an important aspect of the building design process as modern man spends most of the day indoors. This paper reviews the developments in indoor thermal comfort research and practice since the second half

  7. Thermal Response Of Composite Insulation

    Science.gov (United States)

    Stewart, David A.; Leiser, Daniel B.; Smith, Marnell; Kolodziej, Paul

    1988-01-01

    Engineering model gives useful predictions. Pair of reports presents theoretical and experimental analyses of thermal responses of multiple-component, lightweight, porous, ceramic insulators. Particular materials examined destined for use in Space Shuttle thermal protection system, test methods and heat-transfer theory useful to chemical, metallurgical, and ceramic engineers needing to calculate transient thermal responses of refractory composites.

  8. Thermal effects in supercapacitors

    CERN Document Server

    Xiong, Guoping; Fisher, Timothy S

    2015-01-01

    This Brief reviews contemporary research conducted in university and industry laboratories on thermal management in electrochemical energy storage systems (capacitors and batteries) that have been widely used as power sources in many practical applications, such as automobiles, hybrid transport, renewable energy installations, power backup and electronic devices. Placing a particular emphasis on supercapacitors, the authors discuss how supercapacitors, or ultra capacitors, are complementing and  replacing, batteries because of their faster power delivery, longer life cycle and higher coulombic efficiency, while providing higher energy density than conventional electrolytic capacitors. Recent advances in both macro- and micro capacitor technologies are covered. The work facilitates systematic understanding of thermal transport in such devices that can help develop better power management systems.

  9. Encyclopedia of thermal stresses

    CERN Document Server

    2014-01-01

    The Encyclopedia of Thermal Stresses is an important interdisciplinary reference work.  In addition to topics on thermal stresses, it contains entries on related topics, such as the theory of elasticity, heat conduction, thermodynamics, appropriate topics on applied mathematics, and topics on numerical methods. The Encyclopedia is aimed at undergraduate and graduate students, researchers and engineers. It brings together well established knowledge and recently received results. All entries were prepared  by leading experts from all over the world, and are presented in an easily accessible format. The work is lavishly illustrated, examples and applications are given where appropriate, ideas for further development abound, and the work will challenge many students and researchers to pursue new results of their own. This work can also serve as a one-stop resource for all who need succinct, concise, reliable and up to date information in short encyclopedic entries, while the extensive references will be of inte...

  10. 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.

  11. Thermally stable diamond brazing

    Science.gov (United States)

    Radtke, Robert P [Kingwood, TX

    2009-02-10

    A cutting element and a method for forming a cutting element is described and shown. The cutting element includes a substrate, a TSP diamond layer, a metal interlayer between the substrate and the diamond layer, and a braze joint securing the diamond layer to the substrate. The thickness of the metal interlayer is determined according to a formula. The formula takes into account the thickness and modulus of elasticity of the metal interlayer and the thickness of the TSP diamond. This prevents the use of a too thin or too thick metal interlayer. A metal interlayer that is too thin is not capable of absorbing enough energy to prevent the TSP diamond from fracturing. A metal interlayer that is too thick may allow the TSP diamond to fracture by reason of bending stress. A coating may be provided between the TSP diamond layer and the metal interlayer. This coating serves as a thermal barrier and to control residual thermal stress.

  12. Thermal Space in Architecture

    DEFF Research Database (Denmark)

    Petersen, Mads Dines

    Present research is revolving around the design process and the use of digital applications to support the design process among architects. This work is made in relation to the current discussions about sustainable architecture and the increased focus on energy consumption and the comfort in our...... and understanding of spaces in buildings can change significantly and instead of the creation of frozen geometrical spaces, thermal spaces can be created as it is suggested in meteorological architecture where functions are distributed in relation to temperature gradients. This creates an interesting contrast......-introducing an increased adaptability in the architecture can be a part of re-defining the environmental agenda and re-establish a link between the environment of the site and the environment of the architecture and through that an increased appreciation of the sensuous space here framed in discussions about thermal...

  13. Subsystem eigenstate thermalization hypothesis

    Science.gov (United States)

    Dymarsky, Anatoly; Lashkari, Nima; Liu, Hong

    2018-01-01

    Motivated by the qualitative picture of canonical typicality, we propose a refined formulation of the eigenstate thermalization hypothesis (ETH) for chaotic quantum systems. This formulation, which we refer to as subsystem ETH, is in terms of the reduced density matrix of subsystems. This strong form of ETH outlines the set of observables defined within the subsystem for which it guarantees eigenstate thermalization. We discuss the limits when the size of the subsystem is small or comparable to its complement. In the latter case we outline the way to calculate the leading volume-proportional contribution to the von Neumann and Renyi entanglment entropies. Finally, we provide numerical evidence for the proposal in the case of a one-dimensional Ising spin chain.

  14. Solar thermal technology

    Science.gov (United States)

    1988-09-01

    This annual report describes the accomplishments and progress of government-funded activities initiated, renewed, or completed during Fiscal Year (FY) 1987 (October 1, 1986, through September 30, 1987). It highlights the program tasks conducted by participating federal laboratories and by industrial, academic, or other research under a subcontract. The emphasis of the Solar Thermal Technology Program during the year was: (1) to perform research and development leading to the economic viability of two primary solar thermal concepts, central receiver and parabolic dish, and (2) to explore applications of national significance where the special attributes of concentrated sunlight are appropriate. The report includes three appendices that cover principal contacts and sources of additional information (Appendix A), acronyms and abbreviations (Appendix B), and a glossary of terms (Appendix C). A bibliography of relevant publications from Sandia National Laboratories and the Solar Energy Research Institute completes this annual report.

  15. Surface modification of layered silicates. II. Factors affecting thermal stability

    Science.gov (United States)

    Mittal, Vikas

    2012-12-01

    Different aluminosilicates, such as montmorillonite, vermiculite and mica, were surface-treated with a variety of organic modifiers to quantify factors affecting the thermal stability of the modified fillers. Montmorillonites with different cation exchange capacities were also used. Thermal characterisation was carried out via high resolution thermogravimetric analysis and the results were correlated with X-ray diffraction measurements. Modified substrates, such as montmorillonite, vermiculite and mica, differed in their thermal behaviour even when modified with the same surface modifiers. Phosphonium-based modifiers were the most thermally stable, compared to pyridinium and ammonium ions. Mixed brushes from the modifiers also influenced the thermal behaviour of the modified substrates. When further modified using physical adsorption or chemical reactions on the surface, the modified minerals also displayed alterations in the thermal behaviour of the fillers. The results can be used as a guide for the selection of surface modifiers in the nanocomposite synthesis process where compounding of the filler with the polymer at high temperature and shear is required.

  16. Genetic alterations in pancreatic carcinoma

    Directory of Open Access Journals (Sweden)

    Schmid Roland M

    2003-01-01

    Full Text Available Abstract Cancer of the exocrine pancreas represents the fifth leading cause of cancer death in the Western population with an average survival after diagnosis of 3 to 6 months and a five-year survival rate under 5%. Our understanding of the molecular carcinogenesis has improved in the last few years due to the development of novel molecular biological techniques. Pancreatic cancer is a multi-stage process resulting from the accumulation of genetic changes in the somatic DNA of normal cells. In this article we describe major genetic alterations of pancreatic cancer, mutations in the proto-oncogene K-RAS and the tumor suppressors INK4A, TP53 and DPC4/SMAD4. The accumulation of these genetic changes leads to a profound disturbance in cell cycle regulation and continuous growth. The knowledge of the underlying molecular mechanisms will offer new therapeutic and diagnostic options and hopefully improve the outcome of this aggressive disease.

  17. Epigenetic alterations underlying autoimmune diseases.

    Science.gov (United States)

    Aslani, Saeed; Mahmoudi, Mahdi; Karami, Jafar; Jamshidi, Ahmad Reza; Malekshahi, Zahra; Nicknam, Mohammad Hossein

    2016-01-01

    Recent breakthroughs in genetic explorations have extended our understanding through discovery of genetic patterns subjected to autoimmune diseases (AID). Genetics, on the contrary, has not answered all the conundrums to describe a comprehensive explanation of causal mechanisms of disease etiopathology with regard to the function of environment, sex, or aging. The other side of the coin, epigenetics which is defined by gene manifestation modification without DNA sequence alteration, reportedly has come in to provide new insights towards disease apprehension through bridging the genetics and environmental factors. New investigations in genetic and environmental contributing factors for autoimmunity provide new explanation whereby the interactions between genetic elements and epigenetic modifications signed by environmental agents may be responsible for autoimmune disease initiation and perpetuation. It is aimed through this article to review recent progress attempting to reveal how epigenetics associates with the pathogenesis of autoimmune diseases.

  18. Thermal barriers for compartments

    Energy Technology Data Exchange (ETDEWEB)

    Kreutzer, Cory J.; Lustbader, Jason A.

    2017-10-17

    An aspect of the present disclosure is a thermal barrier that includes a core layer having a first surface, a second surface, and a first edge, and a first outer layer that includes a third surface and a second edge, where the third surface substantially contacts the first surface, the core layer is configured to minimize conductive heat transfer through the barrier, and the first outer layer is configured to maximize reflection of light away from the barrier.

  19. Concentrating solar thermal power.

    Science.gov (United States)

    Müller-Steinhagen, Hans

    2013-08-13

    In addition to wind and photovoltaic power, concentrating solar thermal power (CSP) will make a major contribution to electricity provision from renewable energies. Drawing on almost 30 years of operational experience in the multi-megawatt range, CSP is now a proven technology with a reliable cost and performance record. In conjunction with thermal energy storage, electricity can be provided according to demand. To date, solar thermal power plants with a total capacity of 1.3 GW are in operation worldwide, with an additional 2.3 GW under construction and 31.7 GW in advanced planning stage. Depending on the concentration factors, temperatures up to 1000°C can be reached to produce saturated or superheated steam for steam turbine cycles or compressed hot gas for gas turbine cycles. The heat rejected from these thermodynamic cycles can be used for sea water desalination, process heat and centralized provision of chilled water. While electricity generation from CSP plants is still more expensive than from wind turbines or photovoltaic panels, its independence from fluctuations and daily variation of wind speed and solar radiation provides it with a higher value. To become competitive with mid-load electricity from conventional power plants within the next 10-15 years, mass production of components, increased plant size and planning/operating experience will be accompanied by technological innovations. On 30 October 2009, a number of major industrial companies joined forces to establish the so-called DESERTEC Industry Initiative, which aims at providing by 2050 15 per cent of European electricity from renewable energy sources in North Africa, while at the same time securing energy, water, income and employment for this region. Solar thermal power plants are in the heart of this concept.

  20. Thermal reactor safety

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    Information is presented concerning new trends in licensing; seismic considerations and system structural behavior; TMI-2 risk assessment and thermal hydraulics; statistical assessment of potential accidents and verification of computational methods; issues with respect to improved safety; human factors in nuclear power plant operation; diagnostics and activities in support of recovery; LOCA transient analysis; unresolved safety issues and other safety considerations; and fission product transport.

  1. Solar Thermal Concept Evaluation

    Science.gov (United States)

    Hawk, Clark W.; Bonometti, Joseph A.

    1995-01-01

    Concentrated solar thermal energy can be utilized in a variety of high temperature applications for both terrestrial and space environments. In each application, knowledge of the collector and absorber's heat exchange interaction is required. To understand this coupled mechanism, various concentrator types and geometries, as well as, their relationship to the physical absorber mechanics were investigated. To conduct experimental tests various parts of a 5,000 watt, thermal concentrator, facility were made and evaluated. This was in anticipation at a larger NASA facility proposed for construction. Although much of the work centered on solar thermal propulsion for an upper stage (less than one pound thrust range), the information generated and the facility's capabilities are applicable to material processing, power generation and similar uses. The numerical calculations used to design the laboratory mirror and the procedure for evaluating other solar collectors are presented here. The mirror design is based on a hexagonal faceted system, which uses a spherical approximation to the parabolic surface. The work began with a few two dimensional estimates and continued with a full, three dimensional, numerical algorithm written in FORTRAN code. This was compared to a full geometry, ray trace program, BEAM 4, which optimizes the curvatures, based on purely optical considerations. Founded on numerical results, the characteristics of a faceted concentrator were construed. The numerical methodologies themselves were evaluated and categorized. As a result, the three-dimensional FORTRAN code was the method chosen to construct the mirrors, due to its overall accuracy and superior results to the ray trace program. This information is being used to fabricate and subsequently, laser map the actual mirror surfaces. Evaluation of concentrator mirrors, thermal applications and scaling the results of the 10 foot diameter mirror to a much larger concentrator, were studied. Evaluations

  2. Solar thermal conversion

    Science.gov (United States)

    Selcuk, M. K.

    1978-01-01

    A brief review of the fundamentals of the conversion of solar energy into mechanical work (or electricity via generators) is given. Both past and present work on several conversion concepts are discussed. Solar collectors, storage systems, energy transport, and various types of engines are examined. Ongoing work on novel concepts of collectors, energy storage and thermal energy conversion are outlined and projections for the future are described. Energy costs for various options are predicted and margins and limitations are discussed.

  3. THERMAL NEUTRONIC REACTOR

    Science.gov (United States)

    Spinrad, B.I.

    1960-01-12

    A novel thermal reactor was designed in which a first reflector formed from a high atomic weight, nonmoderating material is disposed immediately adjacent to the reactor core. A second reflector composed of a moderating material is disposed outwardly of the first reflector. The advantage of this novel reflector arrangement is that the first reflector provides a high slow neutron flux in the second reflector, where irradiation experiments may be conducted with a small effect on reactor reactivity.

  4. Thermally conductive polymers

    Science.gov (United States)

    Byrd, N. R.; Jenkins, R. K.; Lister, J. L. (Inventor)

    1971-01-01

    A thermally conductive polymer is provided having physical and chemical properties suited to use as a medium for potting electrical components. The polymer is prepared from hydroquinone, phenol, and formaldehyde, by conventional procedures employed for the preparation of phenol-formaldehyde resins. While the proportions of the monomers can be varied, a preferred polymer is formed from the monomers in a 1:1:2.4 molar or ratio of hydroquinone:phenol:formaldehyde.

  5. Methods of forming thermal management systems and thermal management methods

    Science.gov (United States)

    Gering, Kevin L.; Haefner, Daryl R.

    2012-06-05

    A thermal management system for a vehicle includes a heat exchanger having a thermal energy storage material provided therein, a first coolant loop thermally coupled to an electrochemical storage device located within the first coolant loop and to the heat exchanger, and a second coolant loop thermally coupled to the heat exchanger. The first and second coolant loops are configured to carry distinct thermal energy transfer media. The thermal management system also includes an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electrochemical storage device. Thermal management methods are also provided.

  6. Rectenna thermal model development

    Science.gov (United States)

    Kadiramangalam, Murall; Alden, Adrian; Speyer, Daniel

    1992-01-01

    Deploying rectennas in space requires adapting existing designs developed for terrestrial applications to the space environment. One of the major issues in doing so is to understand the thermal performance of existing designs in the space environment. Toward that end, a 3D rectenna thermal model has been developed, which involves analyzing shorted rectenna elements and finite size rectenna element arrays. A shorted rectenna element is a single element whose ends are connected together by a material of negligible thermal resistance. A shorted element is a good approximation to a central element of a large array. This model has been applied to Brown's 2.45 GHz rectenna design. Results indicate that Brown's rectenna requires redesign or some means of enhancing the heat dissipation in order for the diode temperature to be maintained below 200 C above an output power density of 620 W/sq.m. The model developed in this paper is very general and can be used for the analysis and design of any type of rectenna design of any frequency.

  7. Multiscale thermal transport.

    Energy Technology Data Exchange (ETDEWEB)

    Graham, Samuel Jr. (; .); Wong, C. C.; Piekos, Edward Stanley

    2004-02-01

    A concurrent computational and experimental investigation of thermal transport is performed with the goal of improving understanding of, and predictive capability for, thermal transport in microdevices. The computational component involves Monte Carlo simulation of phonon transport. In these simulations, all acoustic modes are included and their properties are drawn from a realistic dispersion relation. Phonon-phonon and phonon-boundary scattering events are treated independently. A new set of phonon-phonon scattering coefficients are proposed that reflect the elimination of assumptions present in earlier analytical work from the simulation. The experimental component involves steady-state measurement of thermal conductivity on silicon films as thin as 340nm at a range of temperatures. Agreement between the experiment and simulation on single-crystal silicon thin films is excellent, Agreement for polycrystalline films is promising, but significant work remains to be done before predictions can be made confidently. Knowledge gained from these efforts was used to construct improved semiclassical models with the goal of representing microscale effects in existing macroscale codes in a computationally efficient manner.

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

    DEFF Research Database (Denmark)

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

    2018-01-01

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

  9. Thermal Infrared Remote Sensing of the Yellowstone Geothermal System

    Science.gov (United States)

    Vaughan, R. G.; Keszthelyi, L. P.; Heasler, H.; Jaworowski, C.; Lowenstern, J. B.; Schneider, D. J.

    2009-12-01

    The Yellowstone National Park (YNP) geothermal system is one of the largest in the world, with thousands of individual thermal features ranging in size from a few centimeters to tens of meters across, (e.g., fumaroles, geysers, mud pots and hot spring pools). Together, large concentrations of these thermal features make up dozens of distinct thermal areas, characterized by sparse vegetation, hydrothermally altered rocks, and usually either sinter, travertine, or acid sulfate alteration. The temperature of these thermal features generally ranges from ~30 to ~93 oC, which is the boiling temperature of water at the elevation of Yellowstone. In-situ temperature measurements of various thermal features are sparse in both space and time, but they show a dynamic time-temperature relationship. For example, as geysers erupt and send pulses of warm water down slope, the warm water cools rapidly and is then followed by another pulse of warm water, on time scales of minutes. The total heat flux from the Park’s thermal features has been indirectly estimated from chemical analysis of Cl- flux in water flowing from Yellowstone’s rivers. We are working to provide a more direct measurement, as well as estimates of time variability, of the total heat flux using satellite multispectral thermal infrared (TIR) remote sensing data. Over the last 10 years, NASA’s orbiting ASTER and MODIS instruments have acquired hundreds and thousands of multispectral TIR images, respectively, over the YNP area. Compared with some volcanoes, Yellowstone is a relatively low-temperature geothermal system, with low thermal contrast to the non-geothermal surrounding areas; therefore we are refining existing techniques to extract surface temperature and thermal flux information. This task is complicated by issues such as, during the day, solar heated surfaces may be warmer than nearby geothermal features; and there is some topographic (elevation) influence on surface temperatures, even at night. Still

  10. Fundamentals of spacecraft thermal design.

    Science.gov (United States)

    Lucas, J. W.

    1972-01-01

    The papers deal with and are grouped according to four major issues. These are: surface radiation properties, including synthesis and measurement, space flight effect, and contamination effects; thermal analysis, including reentry vehicle analysis, radiant heat transfer between surfaces, and thermal contact conductance of surfaces; heat pipes, including possible applications, operating characteristics, and design, fabrication and testing of heat pipes; and thermal design, including radiative, ablative, and active cooling thermal protection of the leading edge of a space-shuttle wing, and space station environmental thermal control. Individual items were previously announced in issues 06 and 11, 1971.

  11. High Performance Flexible Thermal Link

    Science.gov (United States)

    Sauer, Arne; Preller, Fabian

    2014-06-01

    The paper deals with the design and performance verification of a high performance and flexible carbon fibre thermal link.Project goal was to design a space qualified thermal link combining low mass, flexibility and high thermal conductivity with new approaches regarding selected materials and processes. The idea was to combine the advantages of existing metallic links regarding flexibility and the thermal performance of high conductive carbon pitch fibres. Special focus is laid on the thermal performance improvement of matrix systems by means of nano-scaled carbon materials in order to improve the thermal performance also perpendicular to the direction of the unidirectional fibres.One of the main challenges was to establish a manufacturing process which allows handling the stiff and brittle fibres, applying the matrix and performing the implementation into an interface component using unconventional process steps like thermal bonding of fibres after metallisation.This research was funded by the German Federal Ministry for Economic Affairs and Energy (BMWi).

  12. Detection of Alteration Induced by Onshore Gas Seeps from ASTER and WorldView-2 Data

    Directory of Open Access Journals (Sweden)

    Sanaz Salati

    2014-04-01

    Full Text Available Hydrocarbon seeps cause chemical and mineralogical changes at the surface, which can be detected by remote sensing. This paper aims at the detection of mineral alteration induced by gas seeps in a marly limestone formation, SW Iran. For this purpose, the multispectral Advance Spaceborne Thermal Emission and Reflection Radiometer (ASTER and the high spatial resolution WorldView-2 (WV-2 data were utilized for mapping surficial rock alteration. In addition, the potential of Visible Near Infrared (VNIR bands of the WV-2 and its high spatial resolution for mapping alterations was determined. Band ratioing, principal component analysis (PCA, data fusion and the boosted regression trees (BRT were applied to enhance and classify the altered and unaltered marly limestone formation. The alteration zones were identified and mapped by remote sensing analyses. Integrating the WV-2 into the ASTER data improved the spatial accuracy of the BRT classifications. The results showed that the BRT classification of the multiple band imagery (created from ASTER and WV-2 using regions of interest (ROIs around field data provides the best discrimination between altered and unaltered areas. It is suggested that the WV-2 dataset can provide a potential tool along higher spectral resolution data for mapping alteration minerals related to hydrocarbon seeps in arid and semi-arid areas.

  13. Thermal and high magnetic field treatment of materials and associated apparatus

    Science.gov (United States)

    Kisner, Roger A.; Wilgen, John B.; Ludtka, Gerard M.; Jaramillo, Roger A.; Mackiewicz-Ludtka, Gail

    2007-01-09

    An apparatus and method for altering characteristics, such as can include structural, magnetic, electrical, optical or acoustical characteristics, of an electrically-conductive workpiece utilizes a magnetic field within which the workpiece is positionable and schemes for thermally treating the workpiece by heating or cooling techniques in conjunction with the generated magnetic field so that the characteristics of the workpiece are effected by both the generated magnetic field and the thermal treatment of the workpiece.

  14. Response of turkey muscle satellite cells to thermal challenge. I. transcriptome effects in proliferating cells

    OpenAIRE

    Reed, Kent M.; Kristelle M Mendoza; Abrahante, Juan E.; Barnes, Natalie E.; Velleman, Sandra G.; Strasburg, Gale M.

    2017-01-01

    Background Climate change poses a multi-dimensional threat to food and agricultural systems as a result of increased risk to animal growth, development, health, and food product quality. This study was designed to characterize transcriptional changes induced in turkey muscle satellite cells cultured under cold or hot thermal challenge to better define molecular mechanisms by which thermal stress alters breast muscle ultrastructure. Results Satellite cells isolated from the pectoralis major mu...

  15. Imaging structural transitions in organometallic molecules on Ag(100) for solar thermal energy storage

    OpenAIRE

    Cho, Jongweon; Pechenezhskiy, Ivan V.; Berbil-Bautista, Luis; Meier, Steven K.; Vollhardt, K. Peter C.; Crommie, Michael F.

    2017-01-01

    The use of opto-thermal molecular energy storage at the nanoscale creates new opportunities for powering future microdevices with flexible synthetic tailorability. Practical application of these molecular materials, however, requires a deeper microscopic understanding of how their behavior is altered by the presence of different types of substrates. Here we present single-molecule resolved scanning tunneling microscopy imaging of thermally- and optically-induced structural transitions in (ful...

  16. Mechanical Alterations Associated with Repeated Treadmill Sprinting under Heat Stress.

    Directory of Open Access Journals (Sweden)

    Olivier Girard

    Full Text Available Examine the mechanical alterations associated with repeated treadmill sprinting performed in HOT (38°C and CON (25°C conditions.Eleven recreationally active males performed a 30-min warm-up followed by three sets of five 5-s sprints with 25-s recovery and 3-min between sets in each environment. Constant-velocity running for 1-min at 10 and 20 km.h-1 was also performed prior to and following sprinting.Mean skin (37.2±0.7 vs. 32.7±0.8°C; P<0.001 and core (38.9±0.2 vs. 38.8±0.3°C; P<0.05 temperatures, together with thermal comfort (P<0.001 were higher following repeated sprinting in HOT vs. CON. Step frequency and vertical stiffness were lower (-2.6±1.6% and -5.5±5.5%; both P<0.001 and contact time (+3.2±2.4%; P<0.01 higher in HOT for the mean of sets 1-3 compared to CON. Running distance per sprint decreased from set 1 to 3 (-7.0±6.4%; P<0.001, with a tendency for shorter distance covered in HOT vs. CON (-2.7±3.4%; P = 0.06. Mean vertical (-2.6±5.5%; P<0.01, horizontal (-9.1±4.4%; P<0.001 and resultant ground reaction forces (-3.0±2.8%; P<0.01 along with vertical stiffness (-12.9±2.3%; P<0.001 and leg stiffness (-8.4±2.7%; P<0.01 decreased from set 1 to 3, independently of conditions. Propulsive power decreased from set 1 to 3 (-16.9±2.4%; P<0.001, with lower propulsive power values in set 2 (-6.6%; P<0.05 in HOT vs. CON. No changes in constant-velocity running patterns occurred between conditions, or from pre-to-post repeated-sprint exercise.Thermal strain alters step frequency and vertical stiffness during repeated sprinting; however without exacerbating mechanical alterations. The absence of changes in constant-velocity running patterns suggests a strong link between fatigue-induced velocity decrements during sprinting and mechanical alterations.

  17. Thermal Energy Conversion Branch

    Science.gov (United States)

    Bielozer, Matthew C.; Schreiber, Jeffrey, G.; Wilson, Scott D.

    2004-01-01

    The Thermal Energy Conversion Branch (5490) leads the way in designing, conducting, and implementing research for the newest thermal systems used in space applications at the NASA Glenn Research Center. Specifically some of the most advanced technologies developed in this branch can be broken down into four main areas: Dynamic Power Systems, Primary Solar Concentrators, Secondary Solar Concentrators, and Thermal Management. Work was performed in the Dynamic Power Systems area, specifically the Stirling Engine subdivision. Today, the main focus of the 5490 branch is free-piston Stirling cycle converters, Brayton cycle nuclear reactors, and heat rejection systems for long duration mission spacecraft. All space exploring devices need electricity to operate. In most space applications, heat energy from radioisotopes is converted to electrical power. The Radioisotope Thermoelectric Generator (RTG) already supplies electricity for missions such as the Cassini Spacecraft. The focus of today's Stirling research at GRC is aimed at creating an engine that can replace the RTG. The primary appeal of the Stirling engine is its high system efficiency. Because it is so efficient, the Stirling engine will significantly reduce the plutonium fuel mission requirements compared to the RTG. Stirling is also being considered for missions such as the lunar/Mars bases and rovers. This project has focused largely on Stirling Engines of all types, particularly the fluidyne liquid piston engine. The fluidyne was developed by Colin D. West. This engine uses the same concepts found in any type of Stirling engine, with the exception of missing mechanical components. All the working components are fluid. One goal was to develop and demonstrate a working Stirling Fluidyne Engine at the 2nd Annual International Energy Conversion Engineering Conference in Providence, Rhode Island.

  18. Risk analysis and climate alteration

    Energy Technology Data Exchange (ETDEWEB)

    Hidy, G.M. (Electric Power Research Institute, Palo Alto, CA (United States))

    1993-01-01

    Largely absent from the recent climate debates have been careful, objective risk analyses that add insight into energy, environment and economic options. Such studies require a distillation of scientific knowledge combined with socio-economic considerations. In support of this goal, work has been initiated to develop an integrated risk assessment framework for climate change. Conceptually, risk analyses are facilitated by integrated assessment models. These include several analytical components. For the risk of climate alteration, the parts can be identified in terms of (a) policy formulation, (b) economic response, (c) greenhouse gas (GHG) dispersion, (d) climate change, (e) ecosystem effects and valuation, and (f) human system effects and valuation. Simple macro-economic models incorporating these components have been developed that have added insight into the costs and apparent benefits of GHG management options. These early, rudimentary models need to be greatly improved with new knowledge to better inform decision makers on optimal management strategies. The early results from integrated analyses have: (a) reinforced the importance of requiring risk-oriented information from general scientific investigation, (b) focused on the need for far better quantitative information on the environmental effects, and (c) identified the need for substantial improvement of information about human values and priorities in different cultural settings. Technological options for managing GHGs have looked at opportunities for improving the effectiveness of the electrical system, and the human management of biospheric processes. 12 refs., 1 fig., 1 tab.

  19. Thermal contact conductance

    CERN Document Server

    Madhusudana, Chakravarti V

    2013-01-01

    The work covers both theoretical and practical aspects of thermal contact conductance. The theoretical discussion focuses on heat transfer through spots, joints, and surfaces, as well as the role of interstitial materials (both planned and inadvertent). The practical discussion includes formulae and data that can be used in designing heat-transfer equipment for a variety of joints, including special geometries and configurations. All of the material has been updated to reflect the latest advances in the field.

  20. Thermal decomposition of illite

    Directory of Open Access Journals (Sweden)

    Araújo José Humberto de

    2004-01-01

    Full Text Available The effect of heat treatment on illite in air at temperatures ranging from 750 to 1150 °C was studied using the Mössbauer effect in 57Fe. The dependence of the Mössbauer parameters and relative percentage of the radiation absorption area was measured as a function of the firing temperature. The onset of thermal structural decomposition occurred at 800 °C. With rising temperature, the formation of hematite (Fe2O3 increased at the expense of the silicate mineral.

  1. Integrated Thermal Energy Storage

    OpenAIRE

    Kopko, William L.

    2016-01-01

    Integrated Thermal Energy Storage (ITES) is a novel concept in improving cooling performance of air-conditioning systems at peak-load conditions. In contrast to conventional chilled-water or ice storage, it uses stored chilled water to subcool condenser refrigerant liquid instead of supplying cooling directly to a cooling load. For typical R-134a and R-410A systems, subcooling increases capacity by approximately .5 to .7%/°F (~.9 to 1.3 %/K) without increasing compressor input power. Even l...

  2. Thermally cleavable surfactants

    Science.gov (United States)

    McElhanon, James R.; Simmons, Blake A.; Zifer, Thomas; Jamison, Gregory M.; Loy, Douglas A.; Rahimian, Kamyar; Long, Timothy M.; Wheeler, David R.; Staiger, Chad L.

    2006-04-04

    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments and the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  3. Hekinan thermal power station

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    Hekinan thermal power station is situated at the port of Kinuura in Aichi Prefecture, Japan. Unit 1 began commercial operation in October 1991, Unit 2 in June 1992 and Unit 3 in April 1993. This brochure gives the specification of the main facilities of the power station, shows its layout; illustrates its pollution control equipment, gives specifications of its flue gas treatment systems and of its large steam turbine, describes its coal handling facilities and gives their specifications, and mentions the power station`s automated control system.

  4. Thermally Driven Elastic Micromachines

    Science.gov (United States)

    Hosaka, Yuto; Yasuda, Kento; Sou, Isamu; Okamoto, Ryuichi; Komura, Shigeyuki

    2017-11-01

    We discuss the directional motion of an elastic three-sphere micromachine in which the spheres are in equilibrium with independent heat baths having different temperatures. Even in the absence of prescribed motion of springs, such a micromachine can gain net motion purely because of thermal fluctuations. A relation connecting the average velocity and the temperatures of the spheres is analytically obtained. This velocity can also be expressed in terms of the average heat flows in the steady state. Our model suggests a new mechanism for the locomotion of micromachines in nonequilibrium biological systems.

  5. TWO STAGE FRAMEWORK FOR ALTERED FINGERPRINT MATCHING

    Directory of Open Access Journals (Sweden)

    T.R. Anoop

    2015-05-01

    Full Text Available Fingerprint alteration is the process of masking one’s identity from personal identification systems especially in boarder control security systems. Failure of matching the altered fingerprint of the criminals against the watch list of fingerprints can help them to break the security system. This fact leads to the need of a method for altered fingerprint matching. This paper presents a two stage method for altered fingerprint matching. In first stage, approximated global ridge orientation field of altered fingerprint is matched against the orientation field of its unaltered mate. If this matching is successful, fingerprints go to second stage. Second stage starts with the selection of unaltered region from the altered FP and same region from the unaltered mates. Matching in this stage is performed by extraction of ridge texture and ridge frequency from the selected region of interest. Euclidian distance is used in both stages to compute the matching score.

  6. Allophane at Mawrth Vallis: Implications for Aqueous Alteration History

    Science.gov (United States)

    Rampe, E. B.; Sharp, T. G.; Kraft, M. D.

    2011-12-01

    The detection of clay minerals and other secondary silicates in light-toned surfaces at Mawrth Vallis from near-infrared (NIR) spectroscopy indicates that this surface experienced aqueous alteration. The types of alteration products can help constrain past aqueous environments to assess habitability. NIR data from OMEGA and CRISM show a Fe/Mg-smectite layer stratigraphically below a layer containing a variety of secondary silicates, including kaolinite, montmorillonite, beidellite, and amorphous silica (Bishop et al., 2010). Detections of Fe/Mg-smectites at Mawrth Vallis suggest that the lower layer experienced aqueous alteration at alkaline pH, while detections of kaolinite and amorphous silica suggest that the upper layer experienced intense acidic alteration (Bibring et al., 2006; Bishop et al., 2008). Thermal-infrared (TIR) spectroscopy is an essential tool for identifying both primary and secondary silicate minerals. Previous models of Thermal Emission Spectrometer (TES) data from Mawrth indicate clays are present in dark surfaces, while amorphous silica is present in light-toned surfaces (Michalski and Fergason, 2009). However, spectral libraries have heretofore lacked nano-crystalline weathering products, such as allophane, that are important constituents of terrestrial soils. Their identification at Mawrth can help further understand alteration environments and soil formation processes. We synthesized allophanes and gels with a range of Si/Al ratios and measured their TIR emission and NIR reflectance spectra. TES data from dark- and light-toned surfaces at Mawrth were modeled using a spectral library containing allophanes and other secondary silicates. Models of dark-toned surfaces identify 20 vol.% allophane, 10% phyllosilicates and zeolites, and 45% basaltic igneous minerals. Models of bright-toned surfaces identify up to 30% allophane, 25% montmorillonite, and 30-35% basaltic igneous minerals. The identification of allophane in bright-toned surfaces is

  7. Light stable isotope study of the Roosevelt Hot Springs thermal area, Southwestern Utah

    Energy Technology Data Exchange (ETDEWEB)

    Rohrs D.T.; Bowman, J.R.

    1980-05-01

    The isotopic composition of hydrogen, oxygen, and carbon has been determined for regional cold springs, thermal fluids, and rocks and minerals from the Roosevelt Hot Springs thermal area. The geothermal system has developed within plutonic granitic rocks and amphibolite facies gneiss, relying upon fracture-controlled permeability for the migration of the thermal fluids. Probably originating as meteoric waters in the upper elevations of the Mineral Mountains, the thermal waters sampled in the production wells display an oxygen isotopic shift of at least +1.2. Depletions of delta /sup 18/O in wole rock, K-feldspar, and biotite have a positive correlation with alteration intensity. W/R mass ratios, calculated from the isotopic shifts of rock and water, range up to 3.0 in a producing horizon of one well, although the K-feldspar has experienced only 30% exchange with the thermal waters. While veinlet quartz has equilibrated with the thermal waters, the /sup 18/O values of K-mica clay, an alteration product of plagioclase, mimic the isotopic composition of K-feldspar and whole rock. This suggests that locally small W/R ratios enable plagioclase to influence its alteration products by isotopic exchange.

  8. Geomagnetic paleointensity in historical pyroclastic density currents: Testing the effects of emplacement temperature and postemplacement alteration

    Science.gov (United States)

    Bowles, Julie A.; Gee, Jeffrey S.; Jackson, Mike J.; Avery, Margaret S.

    2015-10-01

    Thellier-type paleointensity experiments were conducted on welded ash matrix or pumice from the 1912 Novarupta (NV) and 1980 Mt. St. Helens (MSH) pyroclastic density currents (PDCs) with the intention of evaluating their suitability for geomagnetic paleointensity studies. PDCs are common worldwide, but can have complicated thermal and alteration histories. We attempt to address the role that emplacement temperature and postemplacement hydrothermal alteration may play in nonideal paleointensity behavior of PDCs. Results demonstrate two types of nonideal behavior: unstable remanence in multidomain (MD) titanomagnetite, and nonideal behavior linked to fumarolic and vapor phase alteration. Emplacement temperature indirectly influences MSH results by controlling the fraction of homogenous MD versus oxyexsolved pseudo-single domain titanomagnetite. NV samples are more directly influenced by vapor phase alteration. The majority of NV samples show distinct two-slope behavior in the natural remanent magnetization—partial thermal remanent magnetization plots. We interpret this to arise from a (thermo)chemical remanent magnetization associated with vapor phase alteration, and samples with high water content (>0.75% loss on ignition) generate paleointensities that deviate most strongly from the true value. We find that PDCs can be productively used for paleointensity, but that—as with all paleointensity studies—care should be taken in identifying potential postemplacement alteration below the Curie temperature, and that large, welded flows may be more alteration-prone. One advantage in using PDCs is that they typically have greater areal (spatial) exposure than a basalt flow, allowing for more extensive sampling and better assessment of errors and uncertainty.

  9. Thermal modelling using discrete vasculature for thermal therapy: A review.

    Science.gov (United States)

    Kok, H Petra; Gellermann, Johanna; van den Berg, Cornelis A T; Stauffer, Paul R; Hand, Jeffrey W; Crezee, Johannes

    2013-06-01

    Reliable temperature information during clinical hyperthermia and thermal ablation is essential for adequate treatment control, but conventional temperature measurements do not provide 3D temperature information. Treatment planning is a very useful tool to improve treatment quality, and substantial progress has been made over the last decade. Thermal modelling is a very important and challenging aspect of hyperthermia treatment planning. Various thermal models have been developed for this purpose, with varying complexity. Since blood perfusion is such an important factor in thermal redistribution of energy in in vivo tissue, thermal simulations are most accurately performed by modelling discrete vasculature. This review describes the progress in thermal modelling with discrete vasculature for the purpose of hyperthermia treatment planning and thermal ablation. There has been significant progress in thermal modelling with discrete vasculature. Recent developments have made real-time simulations possible, which can provide feedback during treatment for improved therapy. Future clinical application of thermal modelling with discrete vasculature in hyperthermia treatment planning is expected to further improve treatment quality.

  10. Thermal Insulation Test Apparatuses

    Science.gov (United States)

    Berman, Brion

    2005-01-01

    The National Aeronautics and Space Administration (NASA) seeks to license its Thermal Insulation Test Apparatuses. Designed by the Cryogenics Test Laboratory at the John F. Kennedy Space Center (KSC) in Florida, these patented technologies (U.S. Patent Numbers: Cryostat 1 - 6,742,926, Cryostat 2 - 6,487,866, and Cryostat 4 - 6,824,306) allow manufacturers to fabricate and test cryogenic insulation at their production and/or laboratory facilities. These new inventions allow for the thermal performance characterization of cylindrical and flat specimens (e.g., bulk-fill, flat-panel, multilayer, or continuously rolled) over the full range of pressures, from high vacuum to no vacuum, and over the full range of temperatures from 77K to 300K. In today's world, efficient, low-maintenance, low-temperature refrigeration is taking a more significant role, from the food industry, transportation, energy, and medical applications to the Space Shuttle. Most countries (including the United States) have laws requiring commercially available insulation materials to be tested and rated by an accepted methodology. The new Cryostat methods go beyond the formal capabilities of the ASTM methods to provide testing for real systems, including full-temperature differences plus full-range vacuum conditions.

  11. Solar thermal power system

    Science.gov (United States)

    Bennett, Charles L.

    2010-06-15

    A solar thermal power generator includes an inclined elongated boiler tube positioned in the focus of a solar concentrator for generating steam from water. The boiler tube is connected at one end to receive water from a pressure vessel as well as connected at an opposite end to return steam back to the vessel in a fluidic circuit arrangement that stores energy in the form of heated water in the pressure vessel. An expander, condenser, and reservoir are also connected in series to respectively produce work using the steam passed either directly (above a water line in the vessel) or indirectly (below a water line in the vessel) through the pressure vessel, condense the expanded steam, and collect the condensed water. The reservoir also supplies the collected water back to the pressure vessel at the end of a diurnal cycle when the vessel is sufficiently depressurized, so that the system is reset to repeat the cycle the following day. The circuital arrangement of the boiler tube and the pressure vessel operates to dampen flow instabilities in the boiler tube, damp out the effects of solar transients, and provide thermal energy storage which enables time shifting of power generation to better align with the higher demand for energy during peak energy usage periods.

  12. Thermal equilibrium of goats.

    Science.gov (United States)

    Maia, Alex S C; Nascimento, Sheila T; Nascimento, Carolina C N; Gebremedhin, Kifle G

    2016-05-01

    The effects of air temperature and relative humidity on thermal equilibrium of goats in a tropical region was evaluated. Nine non-pregnant Anglo Nubian nanny goats were used in the study. An indirect calorimeter was designed and developed to measure oxygen consumption, carbon dioxide production, methane production and water vapour pressure of the air exhaled from goats. Physiological parameters: rectal temperature, skin temperature, hair-coat temperature, expired air temperature and respiratory rate and volume as well as environmental parameters: air temperature, relative humidity and mean radiant temperature were measured. The results show that respiratory and volume rates and latent heat loss did not change significantly for air temperature between 22 and 26°C. In this temperature range, metabolic heat was lost mainly by convection and long-wave radiation. For temperature greater than 30°C, the goats maintained thermal equilibrium mainly by evaporative heat loss. At the higher air temperature, the respiratory and ventilation rates as well as body temperatures were significantly elevated. It can be concluded that for Anglo Nubian goats, the upper limit of air temperature for comfort is around 26°C when the goats are protected from direct solar radiation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Thermal tachyacoustic cosmology

    Science.gov (United States)

    Agarwal, Abhineet; Afshordi, Niayesh

    2014-08-01

    An intriguing possibility that can address pathologies in both early Universe cosmology (i.e. the horizon problem) and quantum gravity (i.e. nonrenormalizability), is that particles at very high energies and/or temperatures could propagate arbitrarily fast. A concrete realization of this possibility for the early Universe is the tachyacoustic (or speedy sound) cosmology, which could also produce a scale-invariant spectrum for scalar cosmological perturbations. Here, we study thermal tachyacoustic cosmology (TTC), i.e. this scenario with thermal initial conditions. We find that a phase transition in the early Universe, around the scale of the grand unified theory (GUT scale; T ˜1015 GeV), during which the speed of sound drops by 25 orders of magnitude within a Hubble time, can fit current CMB observations. We further discuss how production of primordial black holes constrains the cosmological acoustic history, while coupling TTC to Horava-Lifshitz gravity leads to a lower limit on the amplitude of tensor modes (r≳10-3), that are detectable by CMBpol (and might have already been seen by the BICEP-Keck Collaboration).

  14. Thermal fatigue of beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Deksnis, E.; Ciric, D.; Falter, H. [JET Joint undertaking, Abingdon (United Kingdom)] [and others

    1995-09-01

    Thermal fatigue life of S65c beryllium castellated to a geometry 6 x 6 x (8-10)mm deep has been tested for steady heat fluxes of 3 MW/m{sup 2} to 5 MW/m{sup 2} and under pulsed heat fluxes (10-20 MW/m{sup 2}) for which the time averaged heat flux is 5 MW/m{sup 2}. These tests were carried out in the JET neutral beam test facility A test sequence with peak surface temperatures {le} 600{degrees}C produced no visible fatigue cracks. In the second series of tests, with T{sub max} {le} 750{degrees}C evidence for fatigue appeared after a minimum of 1350 stress cycles. These fatigue data are discussed in view of the observed lack of thermal fatigue in JET plasma operations with beryllium PFC. JET experience with S65b and S65c is reviewed; recent operations with {Phi} = 25 MW/m{sup 2} and sustained melting/resolidification are also presented. The need for a failure criterion for finite element analyses of Be PFC lifetimes is discussed.

  15. Vesta surface thermal properties map

    Science.gov (United States)

    Capria, Maria Teresa; Tosi, F.; De Santis, Maria Cristina; Capaccioni, F.; Ammannito, E.; Frigeri, A.; Zambon, F; Fonte, S.; Palomba, E.; Turrini, D.; Titus, T.N.; Schroder, S.E.; Toplis, M.J.; Liu, J.Y.; Combe, J.-P.; Raymond, C.A.; Russell, C.T.

    2014-01-01

    The first ever regional thermal properties map of Vesta has been derived from the temperatures retrieved by infrared data by the mission Dawn. The low average value of thermal inertia, 30 ± 10 J m−2 s−0.5 K−1, indicates a surface covered by a fine regolith. A range of thermal inertia values suggesting terrains with different physical properties has been determined. The lower thermal inertia of the regions north of the equator suggests that they are covered by an older, more processed surface. A few specific areas have higher than average thermal inertia values, indicative of a more compact material. The highest thermal inertia value has been determined on the Marcia crater, known for its pitted terrain and the presence of hydroxyl in the ejecta. Our results suggest that this type of terrain can be the result of soil compaction following the degassing of a local subsurface reservoir of volatiles.

  16. Infrared thermal imaging in medicine.

    Science.gov (United States)

    Ring, E F J; Ammer, K

    2012-03-01

    This review describes the features of modern infrared imaging technology and the standardization protocols for thermal imaging in medicine. The technique essentially uses naturally emitted infrared radiation from the skin surface. Recent studies have investigated the influence of equipment and the methods of image recording. The credibility and acceptance of thermal imaging in medicine is subject to critical use of the technology and proper understanding of thermal physiology. Finally, we review established and evolving medical applications for thermal imaging, including inflammatory diseases, complex regional pain syndrome and Raynaud's phenomenon. Recent interest in the potential applications for fever screening is described, and some other areas of medicine where some research papers have included thermal imaging as an assessment modality. In certain applications thermal imaging is shown to provide objective measurement of temperature changes that are clinically significant.

  17. Optimal control in thermal engineering

    CERN Document Server

    Badescu, Viorel

    2017-01-01

    This book is the first major work covering applications in thermal engineering and offering a comprehensive introduction to optimal control theory, which has applications in mechanical engineering, particularly aircraft and missile trajectory optimization. The book is organized in three parts: The first part includes a brief presentation of function optimization and variational calculus, while the second part presents a summary of the optimal control theory. Lastly, the third part describes several applications of optimal control theory in solving various thermal engineering problems. These applications are grouped in four sections: heat transfer and thermal energy storage, solar thermal engineering, heat engines and lubrication.Clearly presented and easy-to-use, it is a valuable resource for thermal engineers and thermal-system designers as well as postgraduate students.

  18. Survival and behaviour of juvenile unionid mussels exposed to thermal stress and dewatering in the presence of a sediment temperature gradient

    Science.gov (United States)

    Archambault, L.; Cope, W. Gregory; Kwak, Thomas J.

    2014-01-01

    Freshwater mussels (Unionidae) are a highly imperilled faunal group. One critical threat is thermal sensitivity, because global climate change and other anthropogenic activities contribute to increasing stream temperature and altered hydrologic flow that may be detrimental to freshwater mussels.

  19. Calibrating thermal behavior of electronics

    Science.gov (United States)

    Chainer, Timothy J.; Parida, Pritish R.; Schultz, Mark D.

    2016-05-31

    A method includes determining a relationship between indirect thermal data for a processor and a measured temperature associated with the processor, during a calibration process, obtaining the indirect thermal data for the processor during actual operation of the processor, and determining an actual significant temperature associated with the processor during the actual operation using the indirect thermal data for the processor during actual operation of the processor and the relationship.

  20. Two-dimensional modeling of thermal inversion layers in the middle atmosphere of Mars

    Science.gov (United States)

    Theodore, B.; Chassefiere, E.

    1993-01-01

    There is some evidence that the thermal structure of the martian middle atmosphere may be altered in a significant way by the general circulation motions. Indeed, while it is well known that the circulation in the meridional plane is responsible for the reversal of the latitudinal thermal gradient at the solstice through the adiabatic heating due to sinking motions above the winter pole, here we want to emphasize that a likely by-product effect could be the formation of warm layers, mainly located in the winter hemisphere, and exhibiting an inversion of the vertical thermal gradient.

  1. Thermal energy at the nanoscale

    CERN Document Server

    Fisher, Timothy S

    2014-01-01

    These lecture notes provide a detailed treatment of the thermal energy storage and transport by conduction in natural and fabricated structures. Thermal energy in two carriers, i.e. phonons and electrons -- are explored from first principles. For solid-state transport, a common Landauer framework is used for heat flow. Issues including the quantum of thermal conductance, ballistic interface resistance, and carrier scattering are elucidated. Bulk material properties, such as thermal and electrical conductivity, are derived from particle transport theories, and the effects of spatial confinement on these properties are established. Readership: Students and professionals in physics and engineering.

  2. Cryogenic thermal diode heat pipes

    Science.gov (United States)

    Alario, J.

    1979-01-01

    The development of spiral artery cryogenic thermal diode heat pipes was continued. Ethane was the working fluid and stainless steel the heat pipe material in all cases. The major tasks included: (1) building a liquid blockage (blocking orifice) thermal diode suitable for the HEPP space flight experiment; (2) building a liquid trap thermal diode engineering model; (3) retesting the original liquid blockage engineering model, and (4) investigating the startup dynamics of artery cryogenic thermal diodes. An experimental investigation was also conducted into the wetting characteristics of ethane/stainless steel systems using a specially constructed chamber that permitted in situ observations.

  3. Contribution of thermal expansion and

    Directory of Open Access Journals (Sweden)

    O.I.Pursky

    2007-01-01

    Full Text Available A theoretical model is developed to describe the experimental results obtained for the isobaric thermal conductivity of rare gas solids (RGS. The isobaric thermal conductivity of RGS has been analysed within Debye approximation with regard to the effect of thermal expansion. The suggested model takes into consideration the fact that thermal conductivity is determined by U-processes while above the phonon mobility edge it is determined by "diffusive" modes migrating randomly from site to site. The mobility edge ω0 is determined from the condition that the phonon mean-free path restricted by the U-processes cannot be smaller than half of the phonon wavelength.

  4. Thermally induced delamination of multilayers

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Sarraute, S.; Jørgensen, O.

    1998-01-01

    Steady-state delamination of multilayered structures, caused by stresses arising during processing due to thermal expansion mismatch, is analyzed by a fracture mechanics model based on laminate theory. It is found that inserting just a few interlayers with intermediate thermal expansion coefficie......Steady-state delamination of multilayered structures, caused by stresses arising during processing due to thermal expansion mismatch, is analyzed by a fracture mechanics model based on laminate theory. It is found that inserting just a few interlayers with intermediate thermal expansion...

  5. Role of minerals in thermal alteration of organic matter--II: a material balance.

    Science.gov (United States)

    Tannenbaum, E; Huizinga, B J; Kaplan, I R

    1986-09-01

    Pyrolysis experiments were performed on Green River and Monterey Formation kerogens (Types I and II, respectively) with and without calcite, illite, or montmorillonite at 300 degrees C for 2 to 1,000 hours under dry and hydrous conditions. Pyrolysis products were identified and quantified, and a material balance of product and reactants resulted. Significant differences were found in the products generated by pyrolysis of kerogens with and without minerals. Both illite and montmorillonite adsorb a considerable portion (up to 80%) of the generated bitumen. The adsorbed bitumen is almost exclusively composed of polar compounds and asphaltenes that crack to yield low molecular weight compounds and insoluble pyrobitumen during prolonged heating. Montmorillonite shows the most pronounced adsorptive and catalytic effects. With calcite however, the pyrolysis products are similar to those from kerogen heated alone, and bitumen adsorption is negligible. Applying these results to maturation of organic matter in natural environments, we suggest that a given type of organic matter associated with different minerals in source rocks will yield different products. Furthermore, the different adsorption capacities of minerals exert a significant influence on the migration of polar and high molecular weight compounds generated from the breakdown of kerogen. Therefore, the overall accumulated products from carbonate source rocks are mainly heavy oils with some gas, whereas light oils and gases are the main products from source rocks that contain expandable clays with catalytic and adsorptive properties.

  6. Warmest extreme year in U.S. history alters thermal requirements for tree phenology.

    Science.gov (United States)

    Carter, Jacob M; Orive, Maria E; Gerhart, Laci M; Stern, Jennifer H; Marchin, Renée M; Nagel, Joane; Ward, Joy K

    2017-04-01

    The frequency of extreme warm years is increasing across the majority of the planet. Shifts in plant phenology in response to extreme years can influence plant survival, productivity, and synchrony with pollinators/herbivores. Despite extensive work on plant phenological responses to climate change, little is known about responses to extreme warm years, particularly at the intraspecific level. Here we investigate 43 populations of white ash trees (Fraxinus americana) from throughout the species range that were all grown in a common garden. We compared the timing of leaf emergence during the warmest year in U.S. history (2012) with relatively non-extreme years. We show that (a) leaf emergence among white ash populations was accelerated by 21 days on average during the extreme warm year of 2012 relative to non-extreme years; (b) rank order for the timing of leaf emergence was maintained among populations across extreme and non-extreme years, with southern populations emerging earlier than northern populations; (c) greater amounts of warming units accumulated prior to leaf emergence during the extreme warm year relative to non-extreme years, and this constrained the potential for even earlier leaf emergence by an average of 9 days among populations; and (d) the extreme warm year reduced the reliability of a relevant phenological model for white ash by producing a consistent bias toward earlier predicted leaf emergence relative to observations. These results demonstrate a critical need to better understand how extreme warm years will impact tree phenology, particularly at the intraspecific level.

  7. A standard blood bank donation alters the thermal and cardiovascular responses during subsequent exercise.

    Science.gov (United States)

    Mora-Rodriguez, Ricardo; Aguado-Jimenez, Roberto; Del Coso, Juan; Estevez, Emma

    2012-11-01

    The fear for adverse effects of blood donation on subsequent exercise may prevent physically active people from donating. We studied the impact of a standard blood bank donation (i.e., 450-mL blood withdrawal) on the thermoregulatory and cardiovascular responses to prolonged exercise in the heat. Eight moderately trained, heat-acclimated males cycled for 1 hour at 60% in a hot environment (34.9±0.6 °C) on four occasions: 1) 2 days before blood donation (CON), 2) 2 hours after donation (DON), 3) 2 days after donation (2 DAYS), and 4) 7 days after donation (7 DAYS). Two-thirds of the blood volume withdrawn was endogenously restored before exercise in the DON trial (p<0.05). DON started with increased preexercise rectal temperature (TRE; 0.42±0.1 °C above CON; p<0.05), which resulted in high levels of hyperthermia (i.e., 39.0±0.2 °C) after 1 hour of exercise. Skin temperature (34.5±0.1 °C) and sweat rate (1.15±0.1 L/h) were not affected by DON. However, DON lowered the skin blood flow:TRE relationship and elevated heart rate (HR) above CON (12±4 beats/min; p<0.05) maintaining cardiac output. After 2 DAYS, TRE and HR were restored to CON levels while cardiac output increased above CON (6%; p<0.05) in association with reduced hemoglobin concentration (i.e., peak hemodilution). A blood bank donation increases preexercise TRE. Subsequent exercise in a hot environment results in high levels of hyperthermia and HR. These thermoregulatory and cardiovascular perturbations observed during exercise disappear 2 days after donation. © 2012 American Association of Blood Banks.

  8. Altering Plasmonic Nanoparticle Size Through Thermal Annealing for Improved Photovoltaic Devices

    Science.gov (United States)

    2012-01-01

    INTENTIONALLY LEFT BLANK. 1 1. Introduction Photovoltaics is a method of generating electrical power by converting solar radiation into direct...heated by lamps located on top and below the sample holder and the pyrometer is used to determine the temperature of the sample’s surface, which is

  9. ALTERATION OF THERMAL BALANCE: HYPERTHERMIA, HYPERTHERMIC REACTIONS, HEAT STROKE, AND SUNSTROKE

    Directory of Open Access Journals (Sweden)

    P.F. Litvitskiy

    2010-01-01

    Full Text Available Author analyzes an etiology, key components of pathogenesis and symptoms of hyperthermic states: hyperthermia, hyperthermic reactions, heat stroke, and sunstroke, adaptive and pathogenic effects, developing in these conditions, and principles of their etiotropic, pathogenetic and symptomatic therapy.Key words: hyperthermic states, disconnectors of oxidative phosphorylation, hypoxia, toxemia.(Voprosy sovremennoi pediatrii — Current Pediatrics. 2010;9(1:96-102

  10. Role of minerals in thermal alteration of organic matter. II - A material balance

    Science.gov (United States)

    Tannenbaum, Eli; Huizinga, Bradley J.; Kaplan, I. R.

    1986-01-01

    The paper presents the results of pyrolysis experiments which were carried out on Green River and Monterey Formation kerogens with and without calcite, illite, or montmorillonite at 300 C for 2 to 1,000 hours under dry and hydrous conditions. The data reveal significant differences in the products generated by pyrolysis of kerogens with and without minerals. Both illite and montmorillonite adsorb a considerable portion of the generated bitumen. In the case of calcite, the pyrolysis products are similar to those from kerogen heated alone, and bitumen adsorption is negligible.

  11. Transient thermal analysis of a titanium multiwall thermal protection system

    Science.gov (United States)

    Blosser, M. L.

    1982-01-01

    The application of the SPAR thermal analyzer to the thermal analysis of a thermal protection system concept is discussed. The titanium multiwall thermal protection system concept consists of alternate flat and dimpled sheets which are joined together at the crests of the dimples and formed into 30 cm by 30 cm (12 in. by 12 in.) tiles. The tiles are mechanically attached to the structure. The complex tile geometry complicates thermal analysis. Three modes of heat transfer were considered: conduction through the gas inside the tile, conduction through the metal, and radiation between the various layers. The voids between the dimpled and flat sheets were designed to be small enough so that natural convection is insignificant (e.g., Grashof number 1000). A two step approach was used in the thermal analysis of the multiwall thermal protection system. First, an effective normal (through-the-thickness) thermal conductivity was obtained from a steady state analysis using a detailed SPAR finite element model of a small symmetric section of the multiwall tile. This effective conductivity was then used in simple one dimensional finite element models for preliminary analysis of several transient heat transfer problems.

  12. Thermal performance and heat transport in aquifer thermal energy storage

    NARCIS (Netherlands)

    Sommer, W.T.; Doornenbal, P.J.; Drijver, B.C.; Gaans, van P.F.M.; Leusbrock, I.; Grotenhuis, J.T.C.; Rijnaarts, H.H.M.

    2014-01-01

    Aquifer thermal energy storage (ATES) is used for seasonal storage of large quantities of thermal energy. Due to the increasing demand for sustainable energy, the number of ATES systems has increased rapidly, which has raised questions on the effect of ATES systems on their surroundings as well as

  13. The Effect of Core Configuration on Thermal Barrier Thermal Performance

    Science.gov (United States)

    DeMange, Jeffrey J.; Bott, Robert H.; Druesedow, Anne S.

    2015-01-01

    Thermal barriers and seals are integral components in the thermal protection systems (TPS) of nearly all aerospace vehicles. They are used to minimize heat transfer through interfaces and gaps and protect underlying temperature-sensitive components. The core insulation has a significant impact on both the thermal and mechanical properties of compliant thermal barriers. Proper selection of an appropriate core configuration to mitigate conductive, convective and radiative heat transfer through the thermal barrier is challenging. Additionally, optimization of the thermal barrier for thermal performance may have counteracting effects on mechanical performance. Experimental evaluations have been conducted to better understand the effect of insulation density on permeability and leakage performance, which can significantly impact the resistance to convective heat transfer. The effect of core density on mechanical performance was also previously investigated and will be reviewed. Simple thermal models were also developed to determine the impact of various core parameters on downstream temperatures. An extended understanding of these factors can improve the ability to design and implement these critical TPS components.

  14. [Epigenetic alterations in acute lymphoblastic leukemia].

    Science.gov (United States)

    Navarrete-Meneses, María Del Pilar; Pérez-Vera, Patricia

    Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. It is well-known that genetic alterations constitute the basis for the etiology of ALL. However, genetic abnormalities are not enough for the complete development of the disease, and additional alterations such as epigenetic modifications are required. Such alterations, like DNA methylation, histone modifications, and noncoding RNA regulation have been identified in ALL. DNA hypermethylation in promoter regions is one of the most frequent epigenetic modifications observed in ALL. This modification frequently leads to gene silencing in tumor suppressor genes, and in consequence, contributes to leukemogenesis. Alterations in histone remodeling proteins have also been detected in ALL, such as the overexpression of histone deacetylases enzymes, and alteration of acetyltransferases and methyltransferases. ALL also shows alteration in the expression of miRNAs, and in consequence, the modification in the expression of their target genes. All of these epigenetic modifications are key events in the malignant transformation since they lead to the deregulation of oncogenes as BLK, WNT5B and WISP1, and tumor suppressors such as FHIT, CDKN2A, CDKN2B, and TP53, which alter fundamental cellular processes and potentially lead to the development of ALL. Both genetic and epigenetic alterations contribute to the development and evolution of ALL. Copyright © 2017 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

  15. Do invasive plant species alter soil health?

    Science.gov (United States)

    Invasive species may alter soil characteristics or interact with the soil microbial community to yield a competitive advantage. Our objectives were to determine: if invasive plant species alter soil properties important to soil health; and the long-term effects of invasive plant species on soil pro...

  16. Seafloor alteration, oxygen isotopes and climate

    Science.gov (United States)

    Kanzaki, Y.; Kump, L. R.; Kasting, J. F.

    2016-12-01

    Seafloor alteration can be related to climate in two ways: through storage of carbon dioxide as carbonates and indirectly through its influence on the oxygen isotopic composition of seawater. Low temperature alteration of the seafloor, or seafloor weathering, can store carbon dioxide as carbonates formed as the result of dissolution of cations from silicate rocks, and since this process is temperature dependent, can serve as a climate regulator. On the other hand, the oxygen isotopic composition of seawater is determined by the balance between low temperature crustal alteration (including continental weathering) and high temperature seafloor alteration, because the heavy isotope is depleted from and added to seawater in low and high temperature alteration, respectively. The oxygen isotopic composition of seawater is a parameter necessary to estimate surface temperature of the Earth from the oxygen isotopic composition of authigenic sedimentary rocks. Thus seafloor alteration is related to reconstruction of Earth's climate. We have developed a comprehensive model of seafloor alteration that captures both seafloor weathering and oxygen isotope exchange, and use it to reconcile observations of long-term stability in both climate and altered ocean crust δ18O with secular changes in the oxygen isotopic composition of marine sediments.

  17. Exposure to high ambient temperatures alters embryology in rabbits

    Science.gov (United States)

    García, M. L.; Argente, M. J.

    2017-09-01

    High ambient temperatures are a determining factor in the deterioration of embryo quality and survival in mammals. The aim of this study was to evaluate the effect of heat stress on embryo development, embryonic size and size of the embryonic coats in rabbits. A total of 310 embryos from 33 females in thermal comfort zone and 264 embryos of 28 females in heat stress conditions were used in the experiment. The traits studied were ovulation rate, percentage of total embryos, percentage of normal embryos, embryo area, zona pellucida thickness and mucin coat thickness. Traits were measured at 24 and 48 h post-coitum (hpc); mucin coat thickness was only measured at 48 hpc. The embryos were classified as zygotes or two-cell embryos at 24 hpc, and 16-cells or early morulae at 48 hpc. The ovulation rate was one oocyte lower in heat stress conditions than in thermal comfort. Percentage of normal embryos was lower in heat stress conditions at 24 hpc (17.2%) and 48 hpc (13.2%). No differences in percentage of zygotes or two-cell embryos were found at 24 hpc. The embryo development and area was affected by heat stress at 48 hpc (10% higher percentage of 16-cells and 883 μm2 smaller, respectively). Zona pellucida was thicker under thermal stress at 24 hpc (1.2 μm) and 48 hpc (1.5 μm). No differences in mucin coat thickness were found. In conclusion, heat stress appears to alter embryology in rabbits.

  18. Thermal hysteresis proteins.

    Science.gov (United States)

    Barrett, J

    2001-02-01

    Extreme environments present a wealth of biochemical adaptations. Thermal hysteresis proteins (THPs) have been found in vertebrates, invertebrates, plants, bacteria and fungi and are able to depress the freezing point of water (in the presence of ice crystals) in a non-colligative manner by binding to the surface of nascent ice crystals. The THPs comprise a disparate group of proteins with a variety of tertiary structures and often no common sequence similarities or structural motifs. Different THPs bind to different faces of the ice crystal, and no single mechanism has been proposed to account for THP ice binding affinity and specificity. Experimentally THPs have been used in the cryopreservation of tissues and cells and to induce cold tolerance in freeze susceptible organisms. THPs represent a remarkable example of parallel and convergent evolution with different proteins being adapted for an anti-freeze role.

  19. Thermal energy test apparatus

    Science.gov (United States)

    Audet, N. F.

    1991-10-01

    The Navy Clothing and Textile Research Facility (NCTRF) designed and fabricated a thermal energy test apparatus to permit evaluation of the heat protection provided by crash crew firefighter's proximity clothing materials against radiant and convective heat loads, similar to those found outside the flame zone of aircraft fuel fires. The apparatus employs electrically operated quartz lamp radiant heaters and a hot air convective heater assembly to produce the heat load conditions the materials to be subjected to, and is equipped with heat flux sensors of different sensitivities to measure the incident heat flux on the sample material as well as the heat flux transmitted by the sample. Tests of the apparatus have shown that it can produce radiant heat flux levels equivalent to those estimated to be possible in close proximity to large aircraft fuel fires, and can produce convective heat fluxes equivalent to those measured in close proximity to aircraft fuel fires at upwind and sidewind locations. Work was performed in 1974.

  20. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Mengüç, M Pinar

    2011-01-01

    Providing a comprehensive overview of the radiative behavior and properties of materials, the fifth edition of this classic textbook describes the physics of radiative heat transfer, development of relevant analysis methods, and associated mathematical and numerical techniques. Retaining the salient features and fundamental coverage that have made it popular, Thermal Radiation Heat Transfer, Fifth Edition has been carefully streamlined to omit superfluous material, yet enhanced to update information with extensive references. Includes four new chapters on Inverse Methods, Electromagnetic Theory, Scattering and Absorption by Particles, and Near-Field Radiative Transfer Keeping pace with significant developments, this book begins by addressing the radiative properties of blackbody and opaque materials, and how they are predicted using electromagnetic theory and obtained through measurements. It discusses radiative exchange in enclosures without any radiating medium between the surfaces-and where heat conduction...

  1. Thermal radiation heat transfer.

    Science.gov (United States)

    Siegel, R.; Howell, J. R.

    1972-01-01

    A comprehensive discussion of heat transfer by thermal radiation is presented, including the radiative behavior of materials, radiation between surfaces, and gas radiation. Among the topics considered are property prediction by electromagnetic theory, the observed properties of solid materials, radiation in the presence of other modes of energy transfer, the equations of transfer for an absorbing-emitting gas, and radiative transfer in scattering and absorbing media. Also considered are radiation exchange between black isothermal surfaces, radiation exchange in enclosures composed of diffuse gray surfaces and in enclosures having some specularly reflecting surfaces, and radiation exchange between nondiffuse nongray surfaces. The use of the Monte Carlo technique in solving radiant-exchange problems and problems of radiative transfer through absorbing-emitting media is explained.

  2. Comprehensive NMR analysis of compositional changes of black garlic during thermal processing.

    Science.gov (United States)

    Liang, Tingfu; Wei, Feifei; Lu, Yi; Kodani, Yoshinori; Nakada, Mitsuhiko; Miyakawa, Takuya; Tanokura, Masaru

    2015-01-21

    Black garlic is a processed food product obtained by subjecting whole raw garlic to thermal processing that causes chemical reactions, such as the Maillard reaction, which change the composition of the garlic. In this paper, we report a nuclear magnetic resonance (NMR)-based comprehensive analysis of raw garlic and black garlic extracts to determine the compositional changes resulting from thermal processing. (1)H NMR spectra with a detailed signal assignment showed that 38 components were altered by thermal processing of raw garlic. For example, the contents of 11 l-amino acids increased during the first step of thermal processing over 5 days and then decreased. Multivariate data analysis revealed changes in the contents of fructose, glucose, acetic acid, formic acid, pyroglutamic acid, cycloalliin, and 5-(hydroxymethyl)furfural (5-HMF). Our results provide comprehensive information on changes in NMR-detectable components during thermal processing of whole garlic.

  3. AND THERMAL POWER PLANTS

    Directory of Open Access Journals (Sweden)

    Alduhov Oleg Aleksandrovich

    2012-10-01

    Full Text Available Investigation of the atmospheric dispersion as part of the process of selection of sites to accommodate nuclear and thermal power plants is performed to identify concentration fields of emissions and to assess the anthropogenic impact produced on the landscape components and human beings. Scattering properties of the atmospheric boundary layer are mainly determined by the turbulence intensity and the wind field. In its turn, the turbulence intensity is associated with the thermal stratification of the boundary layer. Therefore, research of the atmospheric dispersion is reduced to the study of temperature and wind patterns of the boundary layer. Statistical processing and analysis of the upper-air data involves the input of the data collected by upper-air stations. Until recently, the upper-air data covering the standard period between 1961 and 1970 were applied for these purposes, although these data cannot assure sufficient reliability of assessments in terms of the properties of the atmospheric dispersion. However, recent scientific and technological developments make it possible to substantially increase the data coverage by adding the upper-air data collected within the period between 1964 and 2010. The article has a brief overview of BL_PROGS, a specialized software package designated for the processing of the above data. The software package analyzes the principal properties of the atmospheric dispersion. The use of the proposed software package requires preliminary development of a database that has the information collected by an upper-air station. The software package is noteworthy for the absence of any substantial limitations imposed onto the amount of the input data that may go up in proportion to the amount of the upper-air data collected by upper-air stations.

  4. Comparison of specific methane yield of perennial ryegrass prepared by thermal drying versus non-thermal drying in small-scale batch digestion tests.

    Science.gov (United States)

    Nolan, P; McEniry, J; Doyle, E M; O'Kiely, P

    2014-10-01

    Dried milled biomass samples are frequently utilised in small-scale batch digestion tests. However, herbage chemical composition can be altered by thermal drying, and this may affect specific methane (CH4) yields. Thus, the specific CH4 yield of herbage pre- and post-ensiling, prepared by two preparation methods were compared. Perennial ryegrass samples were either non-thermally dried (i.e. subject to cryogenic conditions, -196 °C) or thermally dried (40 °C), prior to milling. Specific CH4 yield was subsequently determined in a small-scale batch digestion test. Herbage pre-ensiling yielded 204 and 243 L CH4 kg(-1)VS(added) and herbage post-ensiling yielded 212 and 188 L CH4 kg(-1)VS(added) with non-thermal dried and thermal dried sample preparation methods, respectively. Due to opposing effects of thermal drying on CH4 yields of herbage either pre- or post-ensiling, it is not recommended to use thermal drying. Instead, it is recommended that non-thermal dried herbage samples are used in small-scale batch digestion tests. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Thermal resistance of light emitting diode PCB with thermal vias.

    Science.gov (United States)

    Lee, Hyo Soo; Shin, Hyung Won; Jung, Seung Boo

    2012-04-01

    Light emitting diodes (LEDs) are already familiar for use as lighting sources in various electronic devices and displays. LEDs have many advantages such as long life, low power consumption, and high reliability. In the future, as an alternative to fluorescent lighting, LEDs are certain to receive much attention. However, in components related to advanced LED packages or modules there has been an issue regarding the heat from the LED chip. The LED chip is still being developed for use in high-power devices which generate more heat. In this study, we investigate the variation of thermal resistance in LED modules embedded with thermal vias. Through the analysis of thermal resistance with various test vehicles, we obtained the concrete relationship between thermal resistance and the thermal via structure.

  6. Quantitative assessment of pain-related thermal dysfunction through clinical digital infrared thermal imaging

    Directory of Open Access Journals (Sweden)

    Frize Monique

    2004-06-01

    Full Text Available Abstract Background The skin temperature distribution of a healthy human body exhibits a contralateral symmetry. Some nociceptive and most neuropathic pain pathologies are associated with an alteration of the thermal distribution of the human body. Since the dissipation of heat through the skin occurs for the most part in the form of infrared radiation, infrared thermography is the method of choice to study the physiology of thermoregulation and the thermal dysfunction associated with pain. Assessing thermograms is a complex and subjective task that can be greatly facilitated by computerised techniques. Methods This paper presents techniques for automated computerised assessment of thermal images of pain, in order to facilitate the physician's decision making. First, the thermal images are pre-processed to reduce the noise introduced during the initial acquisition and to extract the irrelevant background. Then, potential regions of interest are identified using fixed dermatomal subdivisions of the body, isothermal analysis and segmentation techniques. Finally, we assess the degree of asymmetry between contralateral regions of interest using statistical computations and distance measures between comparable regions. Results The wavelet domain-based Poisson noise removal techniques compared favourably against Wiener and other wavelet-based denoising methods, when qualitative criteria were used. It was shown to improve slightly the subsequent analysis. The automated background removal technique based on thresholding and morphological operations was successful for both noisy and denoised images with a correct removal rate of 85% of the images in the database. The automation of the regions of interest (ROIs delimitation process was achieved successfully for images with a good contralateral symmetry. Isothermal division complemented well the fixed ROIs division based on dermatomes, giving a more accurate map of potentially abnormal regions. The measure

  7. Quantitative assessment of pain-related thermal dysfunction through clinical digital infrared thermal imaging

    Science.gov (United States)

    Herry, Christophe L; Frize, Monique

    2004-01-01

    Background The skin temperature distribution of a healthy human body exhibits a contralateral symmetry. Some nociceptive and most neuropathic pain pathologies are associated with an alteration of the thermal distribution of the human body. Since the dissipation of heat through the skin occurs for the most part in the form of infrared radiation, infrared thermography is the method of choice to study the physiology of thermoregulation and the thermal dysfunction associated with pain. Assessing thermograms is a complex and subjective task that can be greatly facilitated by computerised techniques. Methods This paper presents techniques for automated computerised assessment of thermal images of pain, in order to facilitate the physician's decision making. First, the thermal images are pre-processed to reduce the noise introduced during the initial acquisition and to extract the irrelevant background. Then, potential regions of interest are identified using fixed dermatomal subdivisions of the body, isothermal analysis and segmentation techniques. Finally, we assess the degree of asymmetry between contralateral regions of interest using statistical computations and distance measures between comparable regions. Results The wavelet domain-based Poisson noise removal techniques compared favourably against Wiener and other wavelet-based denoising methods, when qualitative criteria were used. It was shown to improve slightly the subsequent analysis. The automated background removal technique based on thresholding and morphological operations was successful for both noisy and denoised images with a correct removal rate of 85% of the images in the database. The automation of the regions of interest (ROIs) delimitation process was achieved successfully for images with a good contralateral symmetry. Isothermal division complemented well the fixed ROIs division based on dermatomes, giving a more accurate map of potentially abnormal regions. The measure of distance between

  8. TEMPERATURE DEPENDENCE OF THE THERMAL ...

    African Journals Online (AJOL)

    Thermal conductivity values, in the temperature range 300 – 1200 K, have been measured in air and at atmospheric pressure for a Kenyan kaolinite refractory with 0% - 50% grog proportions. The experimental thermal conductivity values were then compared with those calculated using the Zumbrunnen et al [1] and the ...

  9. Thermal decomposition of natural dolomite

    Indian Academy of Sciences (India)

    Keywords. TGA–DTA; FTIR; X-ray diffraction; dolomite. Abstract. Thermal decomposition behaviour of dolomite sample has been studied by thermogravimetric (TG) measurements. Differential thermal analysis (DTA) curve of dolomite shows two peaks at 777.8°C and 834°C. The two endothermic peaks observed in dolomite ...

  10. Thermal plumes in ventilated rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    1990-01-01

    The design of a displacement ventilation system involves determination of the flow rate in the thermal plumes. The flow rate in the plumes and the vertical temperature gradient influence each other, and they are influenced by many factors. This paper shows some descriptions of these effects. Free...... to be the only possible approach to obtain the volume flow in: thermal plumes in ventilated rooms....

  11. Concentrated solar thermal power - Now

    Energy Technology Data Exchange (ETDEWEB)

    Aringhoff, R.; Brakmann, G. [Solar Thermal Power Industry Association ESTIA, Avenue de la Fauconnerie 73, 1170 Brussels (Belgium); Geyer, M. [IEA SolarPACES Implementing Agreement, Avenida de la Paz 51, 04720 Aguadulce, Almeria (Spain); Teske, S. [Greenpeace International, Ottho Heldringstraat 5, 1066 AZ Amsterdam (Netherlands)

    2005-09-15

    This report demonstrates that there are no technical, economic or resource barriers to supplying 5% of the world's electricity needs from solar thermal power by 2040. It is written as practical blueprint to improve understanding of the solar thermal contribution to the world energy supply.

  12. Cratons' thermal state in China

    Science.gov (United States)

    He, Lijuan; Zhang, Linyou

    2017-04-01

    There are three cratons in China, the North China Craton, the Tarim Craton, and the Yangtze Craton. Each craton has experienced complicated evolution histories since their formation, presents distinct thermal regime, and displays different stability. The Tarim Craton keeps its stability till now. The eastern North China Craton has been destructed in the Mesozoic, but the western North China Craton still stable. The stability of the Yangtze craton is a controversial issue, and the newest study believed it experienced similar tectono-thermal events as the North China Craton and has also been destructed in the Mesozoic. Several sedimentary basins developed in these cratons, and most of them are rich of oil-gas resources. These basins have different formation mechanism and experienced distinct tectono-thermal evolution, which resulted in individual thermal histories. The sedimentary basins have recorded distinct thermal evolution of these craton. We analyze the heat flow data, lithospheric thermal thickness, basins' thermal histories together with tectono-thermal events in these cratons, with aim to provide ideas for geodynamical mechanism on the craton stability/destruction, as well as implications for hydrocarbon generation.

  13. Peg supported thermal insulation panel

    Science.gov (United States)

    Nowobilski, Jeffert J.; Owens, William J.

    1985-01-01

    A thermal insulation panel which is lightweight, load bearing, accommodates thermal stress, and has excellent high temperature insulation capability comprising high performance insulation between thin metal walls supported by high density, high strength glass pegs made in compliance with specified conditions of time, temperature and pressure.

  14. Flexible-pile thermal sealant

    Science.gov (United States)

    Anderson, G. E.; Fell, D. M.; Tesinsky, J. S.

    1977-01-01

    Brushlike material insulates variable-width gaps where severe thermal stress is present. Weave-and-tuft strip has low thermal conductivity, working temperature range from -454 to 2,000 F, low load compressibility, and good inhibition of plasma flow.

  15. Thermal Performance Benchmarking: Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xuhui [National Renewable Energy Laboratory (NREL), Golden, CO (United States). Transportation and Hydrogen Systems Center

    2017-10-19

    In FY16, the thermal performance of the 2014 Honda Accord Hybrid power electronics thermal management systems were benchmarked. Both experiments and numerical simulation were utilized to thoroughly study the thermal resistances and temperature distribution in the power module. Experimental results obtained from the water-ethylene glycol tests provided the junction-to-liquid thermal resistance. The finite element analysis (FEA) and computational fluid dynamics (CFD) models were found to yield a good match with experimental results. Both experimental and modeling results demonstrate that the passive stack is the dominant thermal resistance for both the motor and power electronics systems. The 2014 Accord power electronics systems yield steady-state thermal resistance values around 42- 50 mm to the 2nd power K/W, depending on the flow rates. At a typical flow rate of 10 liters per minute, the thermal resistance of the Accord system was found to be about 44 percent lower than that of the 2012 Nissan LEAF system that was benchmarked in FY15. The main reason for the difference is that the Accord power module used a metalized-ceramic substrate and eliminated the thermal interface material layers. FEA models were developed to study the transient performance of 2012 Nissan LEAF, 2014 Accord, and two other systems that feature conventional power module designs. The simulation results indicate that the 2012 LEAF power module has lowest thermal impedance at a time scale less than one second. This is probably due to moving low thermally conductive materials further away from the heat source and enhancing the heat spreading effect from the copper-molybdenum plate close to the insulated gate bipolar transistors. When approaching steady state, the Honda system shows lower thermal impedance. Measurement results of the thermal resistance of the 2015 BMW i3 power electronic system indicate that the i3 insulated gate bipolar transistor module has significantly lower junction

  16. Dispersion stability of thermal nanofluids

    Directory of Open Access Journals (Sweden)

    Fan Yu

    2017-10-01

    Full Text Available Thermal nanofluids, the engineered fluids with dispersed functional nanoparticles, have exhibited extraordinary thermophysical properties and added functionalities, and thus have enabled a broad range of important applications. The poor dispersion stability of thermal nanofluids, however, has been considered as a long-existing issue that limits their further development and practical application. This review overviews the recent efforts and progresses in improving the dispersion stability of thermal nanofluids such as mechanistic understanding of dispersion behavior of nanofluids, examples of both water-based and oil-based nanofluids, strategies to stabilize nanofluids, and characterization techniques for dispersion behavior of nanofluids. Finally, on-going research needs, and possible solutions to research challenges and future research directions in exploring stably dispersed thermal nanofluids are discussed. Keywords: Thermal nanofluids, Dispersion, Aggregation, Electrostatic stabilization, Steric stabilization

  17. Hybrid Multifoil Aerogel Thermal Insulation

    Science.gov (United States)

    Sakamoto, Jeffrey; Paik, Jong-Ah; Jones, Steven; Nesmith, Bill

    2008-01-01

    This innovation blends the merits of multifoil insulation (MFI) with aerogel-based insulation to develop a highly versatile, ultra-low thermally conductive material called hybrid multifoil aerogel thermal insulation (HyMATI). The density of the opacified aerogel is 240 mg/cm3 and has thermal conductivity in the 20 mW/mK range in high vacuum and 25 mW/mK in 1 atmosphere of gas (such as argon) up to 800 C. It is stable up to 1,000 C. This is equal to commercially available high-temperature thermal insulation. The thermal conductivity of the aerogel is 36 percent lower compared to several commercially available insulations when tested in 1 atmosphere of argon gas up to 800 C.

  18. Effect of thermal and radio frequency electric fields treatments on Escherichia coli bacteria in apple juice

    Science.gov (United States)

    The need for a non-thermal intervention technology that can achieve microbial safety without altering nutritional quality of liquid foods led to the development of the radio frequency electric fields (RFEF) process. However, insight into the mechanism of bacterial inactivation by this technology is ...

  19. Big biology meets microclimatology: Defining thermal niches of ectotherms at landscape scales for conservation planning

    Science.gov (United States)

    Daniel J. Isaak; Seth J. Wenger; Michael K. Young

    2017-01-01

    Temperature profoundly affects ecology, a fact ever more evident as the ability to measure thermal environments increases and global changes alter these environments. The spatial structure of thermalscapes is especially relevant to the distribution and abundance of ectothermic organisms but the ability to describe biothermal relationships at extents and grains relevant...

  20. Laser-induced thermal coagulation enhances skin uptake of topically applied compounds

    DEFF Research Database (Denmark)

    Haak, C S; Hannibal, J; Paasch, U

    2017-01-01

    BACKGROUND: Ablative fractional laser (AFL) generates microchannels in skin surrounded by a zone of thermally altered tissue, termed the coagulation zone (CZ). The thickness of CZ varies according to applied wavelength and laser settings. It is well-known that AFL channels facilitate uptake...

  1. Epigenetic Alterations in Colorectal Cancer: Emerging Biomarkers

    Science.gov (United States)

    Okugawa, Yoshinaga; Grady, William M.; Goel, Ajay

    2015-01-01

    Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. One of the fundamental processes driving the initiation and progression of CRC is the accumulation of a variety of genetic and epigenetic changes in colon epithelial cells. Over the past decade, major advances have been made in our understanding of cancer epigenetics, particularly regarding aberrant DNA methylation, microRNA (miRNA) and noncoding RNA deregulation, and alterations in histone modification states. Assessment of the colon cancer “epigenome” has revealed that virtually all CRCs have aberrantly methylated genes and altered miRNA expression. The average CRC methylome has hundreds to thousands of abnormally methylated genes and dozens of altered miRNAs. As with gene mutations in the cancer genome, a subset of these epigenetic alterations, called driver events, is presumed to have a functional role in CRC. In addition, the advances in our understanding of epigenetic alterations in CRC have led to these alterations being developed as clinical biomarkers for diagnostic, prognostic and therapeutic applications. Progress in this field suggests that these epigenetic alterations will be commonly used in the near future to direct the prevention and treatment of CRC. PMID:26216839

  2. Length-dependent thermal transport and ballistic thermal conduction

    Directory of Open Access Journals (Sweden)

    Bor-Woei Huang

    2015-05-01

    Full Text Available Probing length-dependent thermal conductivity of a given material has been considered as an important experimental method to determine the length of ballistic thermal conduction, or equivalently, the averaged phonon mean free path (l. However, many previous thermal transport measurements have focused on varying the lateral dimensions of samples, rendering the experimental interpretation indirect. Moreover, deducing l is model-dependent in many optical measurement techniques. In addition, finite contact thermal resistances and variations of sample qualities are very likely to obscure the effect in practice, leading to an overestimation of l. We point out that directly investigating one-dimensional length-dependent (normalized thermal resistance is a better experimental method to determine l. In this regard, we find that no clear experimental data strongly support ballistic thermal conduction of Si or Ge at room temperature. On the other hand, data of both homogeneously-alloyed SiGe nanowires and heterogeneously-interfaced Si-Ge core-shell nanowires provide undisputed evidence for ballistic thermal conduction over several micrometers at room temperature.

  3. 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.

  4. 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.

  5. Long-term impacts of prescribed burns on soil thermal conductivity and soil heating at a Colorado Rocky Mountain site: a data/model fusion study

    Science.gov (United States)

    W. J. Massman; J. M. Frank; N. B. Reisch

    2008-01-01

    Heating any soil during a sufficiently intense wild fire or prescribed burn can alter that soil irreversibly, resulting in many significant, and well studied, long-term biological, chemical, and hydrological effects. On the other hand, much less is known about how fire affects the thermal properties and the long-term thermal regime of soils. Such knowledge is important...

  6. Thermal stress relaxation in magnesium composites during thermal cycling

    Energy Technology Data Exchange (ETDEWEB)

    Trojanova, Z.; Lukac, P. (Karlova Univ., Prague (Czech Republic)); Kiehn, J.; Kainer, K.U.; Mordike, B.L. (Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany))

    1998-01-01

    It has been shown that the internal friction of Mg - Saffil metal matrix composites can be influenced by thermal stresses, if MMCc are submitted to thermal cycling between room temperature and an upper temperature of cycling. These stresses can be accommodated by generation and motion of dislocations giving the formation of the microplastic zones. The thermal stress relaxation depends on the upper temperature of cycling, the volume fraction of reinforcement and the matrix composition and can result in plastic deformation and strain hardening of the matrix without applied stress. The internal friction measurements can be used for non destructive investigation of processes which influence the mechanical properties. (orig.)

  7. Thermal to electricity conversion using thermal magnetic properties

    Science.gov (United States)

    West, Phillip B [Idaho Falls, ID; Svoboda, John [Idaho Falls, ID

    2010-04-27

    A system for the generation of Electricity from Thermal Energy using the thermal magnetic properties of a Ferromagnetic, Electrically Conductive Material (FECM) in one or more Magnetic Fields. A FECM is exposed to one or more Magnetic Fields. Thermal Energy is applied to a portion of the FECM heating the FECM above its Curie Point. The FECM, now partially paramagnetic, moves under the force of the one or more Magnetic Fields. The movement of the FECM induces an electrical current through the FECM, generating Electricity.

  8. Perioperative thermal insulation.

    Science.gov (United States)

    Bräuer, Anselm; Perl, Thorsten; English, Michael J M; Quintel, Michael

    2007-01-01

    Perioperative hypothermia remains a common problem during anesthesia and surgery. Unfortunately, the implementation of new minimally invasive surgical procedures has not lead to a reduction of this problem. Heat losses from the skin can be reduced by thermal insulation to avoid perioperative hypothermia. However, only a small amount of information is available regarding the physical properties of insulating materials used in the Operating Room (OR). Therefore, several materials using validated manikins were tested. Heat loss from the surface of the manikin can be described as:"Q = h . DeltaT . A" where Q = heat flux, h = heat exchange coefficient, DeltaT = temperature gradient between the environment and surface, and A = covered area. Heat flux per unit area and surface temperature were measured with calibrated heat flux transducers. Environmental temperature was measured using a thermoanemometer. The temperature gradient between the surface and environment (DeltaT) was varied and "h" was determined by linear regression analysis as the slope of "DeltaT" versus heat flux per unit area. The reciprocal of the heat exchange coefficient defines the insulation. The insulation values of the materials varied between 0.01 Clo (plastic bag) to 2.79 Clo (2 layers of a hospital duvet). Given the range of insulating materials available for outdoor activities, significant improvement in insulation of patients in the OR is both possible and desirable.

  9. Microelectromechanical (MEM) thermal actuator

    Science.gov (United States)

    Garcia, Ernest J [Albuquerque, NM; Fulcher, Clay W. G. [Sandia Park, NM

    2012-07-31

    Microelectromechanical (MEM) buckling beam thermal actuators are disclosed wherein the buckling direction of a beam is constrained to a desired direction of actuation, which can be in-plane or out-of-plane with respect to a support substrate. The actuators comprise as-fabricated, linear beams of uniform cross section supported above the substrate by supports which rigidly attach a beam to the substrate. The beams can be heated by methods including the passage of an electrical current through them. The buckling direction of an initially straight beam upon heating and expansion is controlled by incorporating one or more directional constraints attached to the substrate and proximal to the mid-point of the beam. In the event that the beam initially buckles in an undesired direction, deformation of the beam induced by contact with a directional constraint generates an opposing force to re-direct the buckling beam into the desired direction. The displacement and force generated by the movement of the buckling beam can be harnessed to perform useful work, such as closing contacts in an electrical switch.

  10. Thermally bisignate supramolecular polymerization

    Science.gov (United States)

    Venkata Rao, Kotagiri; Miyajima, Daigo; Nihonyanagi, Atsuko; Aida, Takuzo

    2017-11-01

    One of the enticing characteristics of supramolecular polymers is their thermodynamic reversibility, which is attractive, in particular, for stimuli-responsive applications. These polymers usually disassemble upon heating, but here we report a supramolecular polymerization that occurs upon heating as well as cooling. This behaviour arises from the use of a metalloporphyrin-based tailored monomer bearing eight amide-containing side chains, which assembles into a highly thermostable one-dimensional polymer through π-stacking and multivalent hydrogen-bonding interactions, and a scavenger, 1-hexanol, in a dodecane-based solvent. At around 50 °C, the scavenger locks the monomer into a non-polymerizable form through competing hydrogen bonding. On cooling, the scavenger preferentially self-aggregates, unlocking the monomer for polymerization. Heating also results in unlocking the monomer for polymerization, by disrupting the dipole and hydrogen-bonding interactions with the scavenger. Analogous to 'upper and lower critical solution temperature phenomena' for covalently bonded polymers, such a thermally bisignate feature may lead to supramolecular polymers with tailored complex thermoresponsive properties.

  11. Thermal Sensor Arrays for The Combinatorial Analysis of Thin Films

    Science.gov (United States)

    McCluskey, Patrick James

    2011-12-01

    transport. The parallel nano-scanning calorimeter (PnSC) has an array of sensors optimized to sense changes in enthalpy. In this case heat loss sensitivity is minimized with sensor geometry and a reference measurement scheme. The minimal heat loss and small addendum result in sensitivity on the order of 10 nJ/K at heating rates on the order of 104 K/s. The sensitivity is demonstrated by measuring the characteristics of the melting transformation of a 25 nm In film. The combinatorial capabilities of the device are demonstrated by creating and analyzing a library of thin-film (290 nm) Ni-Ti-Zr samples with in-plane composition gradients. The Ni-Ti-Zr films are crystallized in-situ by local heating and the temperature dependence of the martensite transformation on Zr content is detected. Further analysis of the Ni-Ti-Zr samples reveals that the as-deposited amorphous samples crystallize in a multi-stage process that is a function of composition. The features of the calorimetry traces are identified with the help of x-ray diffraction measurements of the crystallized samples. Crystallization at these fast heating rates results in suppression of structural relaxation, increased crystallization temperature (allowing the detection of the glass transition), and an ultra-fine nanocrystalline grain structure with non-equilibrium phases. The characteristics of the martensite-austenite phase transformation are investigated by PnSC to determine the effects of high-temperature (900°C) heat treatments and low-temperature (450°C) thermal cycling. Heat treatments produce precipitates that vary with Zr content and alter the transformation temperature. Thermal cycling results in the accumulation of plastic deformation, which relaxes internal stresses and reduces the transformation temperature. This effect, known as thermal fatigue, is reduced in these samples due to the ultra-fine grain structure, which suppresses dislocation mobility.

  12. Bioinspired engineering of thermal materials.

    Science.gov (United States)

    Tao, Peng; Shang, Wen; Song, Chengyi; Shen, Qingchen; Zhang, Fangyu; Luo, Zhen; Yi, Nan; Zhang, Di; Deng, Tao

    2015-01-21

    In the development of next-generation materials with enhanced thermal properties, biological systems in nature provide many examples that have exceptional structural designs and unparalleled performance in their thermal or nonthermal functions. Bioinspired engineering thus offers great promise in the synthesis and fabrication of thermal materials that are difficult to engineer through conventional approaches. In this review, recent progress in the emerging area of bioinspired advanced materials for thermal science and technology is summarized. State-of-the-art developments of bioinspired thermal-management materials, including materials for efficient thermal insulation and heat transfer, and bioinspired materials for thermal/infrared detection, are highlighted. The dynamic balance of bioinspiration and practical engineering, the correlation of inspiration approaches with the targeted applications, and the coexistence of molecule-based inspiration and structure-based inspiration are discussed in the overview of the development. The long-term outlook and short-term focus of this critical area of advanced materials engineering are also presented. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. 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.

  14. Thermal Performance Benchmarking: Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilbert

    2016-04-08

    The goal for this project is to thoroughly characterize the performance of state-of-the-art (SOA) automotive power electronics and electric motor thermal management systems. Information obtained from these studies will be used to: Evaluate advantages and disadvantages of different thermal management strategies; establish baseline metrics for the thermal management systems; identify methods of improvement to advance the SOA; increase the publicly available information related to automotive traction-drive thermal management systems; help guide future electric drive technologies (EDT) research and development (R&D) efforts. The performance results combined with component efficiency and heat generation information obtained by Oak Ridge National Laboratory (ORNL) may then be used to determine the operating temperatures for the EDT components under drive-cycle conditions. In FY15, the 2012 Nissan LEAF power electronics and electric motor thermal management systems were benchmarked. Testing of the 2014 Honda Accord Hybrid power electronics thermal management system started in FY15; however, due to time constraints it was not possible to include results for this system in this report. The focus of this project is to benchmark the thermal aspects of the systems. ORNL's benchmarking of electric and hybrid electric vehicle technology reports provide detailed descriptions of the electrical and packaging aspects of these automotive systems.

  15. Sulphur depletion altered somatic embryogenesis in Theobroma ...

    African Journals Online (AJOL)

    Sulphur depletion altered somatic embryogenesis in Theobroma cacao L. Biochemical difference related to sulphur metabolism between embryogenic and non embryogenic calli. Minyaka Emile, Niemenak Nicolas, Issali Emmanuel Auguste, Sangare Abdourahamane, Denis Ndoumou Omokolo ...

  16. Short Communication Relationship between soil alteration index ...

    African Journals Online (AJOL)

    Short Communication Relationship between soil alteration index three (AI3), soil organic matter and tree performance in a 'Cripps Pink'/M7 apple orchard. André H Meyer, John Wooldridge, Joanna F Dames ...

  17. Chronic kidney disease alters intestinal microbial flora

    National Research Council Canada - National Science Library

    Vaziri, Nosratola D; Wong, Jakk; Pahl, Madeleine; Piceno, Yvette M; Yuan, Jun; DeSantis, Todd Z; Ni, Zhenmin; Nguyen, Tien-Hung; Andersen, Gary L

    2013-01-01

    .... Since the biochemical environment shapes the structure and function of the microbiome, we tested whether uremia and/or dietary and pharmacologic interventions in chronic kidney disease alters the microbiome...

  18. Numerical simulation of the LAGEOS thermal behavior and thermal accelerations

    NARCIS (Netherlands)

    Andrés, J.I.; Noomen, R.; Vecellio None, S.

    2006-01-01

    The temperature distribution throughout the LAGEOS satellites is simulated numerically with the objective to determine the resulting thermal force. The different elements and materials comprising the spacecraft, with their energy transfer, have been modeled with unprecedented detail. The radiation

  19. Thermal modelling using discrete vasculature for thermal therapy: A review

    NARCIS (Netherlands)

    Kok, H. Petra; Gellermann, Johanna; van den Berg, Cornelis A. T.; Stauffer, Paul R.; Hand, Jeffrey W.; Crezee, Johannes

    2013-01-01

    Reliable temperature information during clinical hyperthermia and thermal ablation is essential for adequate treatment control, but conventional temperature measurements do not provide 3D temperature information. Treatment planning is a very useful tool to improve treatment quality, and substantial

  20. Do establishing operations alter reinforcement effectiveness?

    OpenAIRE

    Cherpas, Chris

    1993-01-01

    Michael (this issue) defines an establishing operation (EO), such as food deprivation, as (a) altering the effectiveness of reinforcement as well as (b) evoking behavior. Although this dual role for EOs is compelling, it is possible that such operations have only evocative effects (i.e., function only in the form of antecedent control). The main question raised here is how the reinforcement-altering function can be experimentally analyzed. Evolutionary and conceptual implications of the two-f...

  1. Do establishing operations alter reinforcement effectiveness?

    Science.gov (United States)

    Cherpas, C

    1993-01-01

    Michael (this issue) defines an establishing operation (EO), such as food deprivation, as (a) altering the effectiveness of reinforcement as well as (b) evoking behavior. Although this dual role for EOs is compelling, it is possible that such operations have only evocative effects (i.e., function only in the form of antecedent control). The main question raised here is how the reinforcement-altering function can be experimentally analyzed. Evolutionary and conceptual implications of the two-function EO are also considered.

  2. Alterity in Inclusive and Integrative Learning Programmes

    OpenAIRE

    Sagner-Tapia, Johanna Cristina

    2014-01-01

    This qualitative and quantitative investigation was an exploratory case study that examined the alterity relation to the pupils with disability within four chosen school types in the region of Baden-Württemberg, Germany. It explored general patterns in the alterity relation between the members of the inclusive or integrative schools and the pupils with disability. The investigation analyzed whether the members of the school thematized difference and how the absence or presence of that themat...

  3. TOPICAL REVIEW: Negative thermal expansion

    Science.gov (United States)

    Barrera, G. D.; Bruno, J. A. O.; Barron, T. H. K.; Allan, N. L.

    2005-02-01

    There has been substantial renewed interest in negative thermal expansion following the discovery that cubic ZrW2O8 contracts over a temperature range in excess of 1000 K. Substances of many different kinds show negative thermal expansion, especially at low temperatures. In this article we review the underlying thermodynamics, emphasizing the roles of thermal stress and elasticity. We also discuss vibrational and non-vibrational mechanisms operating on the atomic scale that are responsible for negative expansion, both isotropic and anisotropic, in a wide range of materials.

  4. Thermal bridges of modern windows

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Møller, Eva B.; Nielsen, Anker

    2013-01-01

    With its focus on reduced energy consumption, contemporary housing construction requires a highly insulated and airtight building envelope with as few thermal bridges as possible.Windows must be carefully designed, as thermal bridges can lead to surface condensation or mold growth, even...... if the window has an U-factor of 1 W/(m2·K) or lower. This paper describes the development of modern, energy efficient Danish windows with reduced thermal bridges. It focuses on materials, geometry, and sealing of window panes based on a literature review. Examples of modern windows are presented. Experience...

  5. Industrial thermal insulation: an assessment

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, R.G.; Tennery, V.J.; McElroy, D.L.; Godfrey, T.G.; Kolb, J.O.

    1976-03-01

    A large variety of thermal insulation materials is manufactured for application in various temperature ranges and environments. Additional and improved thermal insulation for steam systems is a key area with immediate energy conservation potential in several of the larger energy-consuming industries. Industrial thermal insulation technology was assessed by obtaining input from a variety of sources including insulation manufacturers, system designers, installers, users, consultants, measurement laboratories, open literature, and in-house knowledge. The assessment identified a number of factors relevant to insulation materials and usage that could contribute significantly to improved energy conservation.

  6. Ocean Thermal Extractable Energy Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Ascari, Matthew [Lockheed Martin Corporation, Bethesda, MD (United States)

    2012-10-28

    The Ocean Thermal Extractable Energy Visualization (OTEEV) project focuses on assessing the Maximum Practicably Extractable Energy (MPEE) from the world’s ocean thermal resources. MPEE is defined as being sustainable and technically feasible, given today’s state-of-the-art ocean energy technology. Under this project the OTEEV team developed a comprehensive Geospatial Information System (GIS) dataset and software tool, and used the tool to provide a meaningful assessment of MPEE from the global and domestic U.S. ocean thermal resources.

  7. Sleep Deprivation Alters Choice Strategy Without Altering Uncertainty or Loss Aversion Preferences

    Directory of Open Access Journals (Sweden)

    O'Dhaniel A Mullette-Gillman

    2015-10-01

    Full Text Available Sleep deprivation alters decision making; however, it is unclear what specific cognitive processes are modified to drive altered choices. In this manuscript, we examined how one night of total sleep deprivation (TSD alters economic decision making. We specifically examined changes in uncertainty preferences dissociably from changes in the strategy with which participants engage with presented choice information. With high test-retest reliability, we show that TSD does not alter uncertainty preferences or loss aversion. Rather, TSD alters the information the participants rely upon to make their choices. Utilizing a choice strategy metric which contrasts the influence of maximizing and satisficing information on choice behavior, we find that TSD alters the relative reliance on maximizing information and satisficing information, in the gains domain. This alteration is the result of participants both decreasing their reliance on cognitively-complex maximizing information and a concomitant increase in the use of readily-available satisficing information. TSD did not result in a decrease in overall information use in either domain. These results show that sleep deprivation alters decision making by altering the informational strategies that participants employ, without altering their preferences.

  8. Scattering Solar Thermal Concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Giebink, Noel C. [Pennsylvania State Univ., State College, PA (United States)

    2015-01-31

    This program set out to explore a scattering-based approach to concentrate sunlight with the aim of improving collector field reliability and of eliminating wind loading and gross mechanical movement through the use of a stationary collection optic. The approach is based on scattering sunlight from the focal point of a fixed collection optic into the confined modes of a sliding planar waveguide, where it is transported to stationary tubular heat transfer elements located at the edges. Optical design for the first stage of solar concentration, which entails focusing sunlight within a plane over a wide range of incidence angles (>120 degree full field of view) at fixed tilt, led to the development of a new, folded-path collection optic that dramatically out-performs the current state-of-the-art in scattering concentration. Rigorous optical simulation and experimental testing of this collection optic have validated its performance. In the course of this work, we also identified an opportunity for concentrating photovoltaics involving the use of high efficiency microcells made in collaboration with partners at the University of Illinois. This opportunity exploited the same collection optic design as used for the scattering solar thermal concentrator and was therefore pursued in parallel. This system was experimentally demonstrated to achieve >200x optical concentration with >70% optical efficiency over a full day by tracking with <1 cm of lateral movement at fixed latitude tilt. The entire scattering concentrator waveguide optical system has been simulated, tested, and assembled at small scale to verify ray tracing models. These models were subsequently used to predict the full system optical performance at larger, deployment scale ranging up to >1 meter aperture width. Simulations at an aperture widths less than approximately 0.5 m with geometric gains ~100x predict an overall optical efficiency in the range 60-70% for angles up to 50 degrees from normal. However, the

  9. 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.

  10. Graphene Thermal Properties: Applications in Thermal Management and Energy Storage

    Directory of Open Access Journals (Sweden)

    Jackie D. Renteria

    2014-11-01

    Full Text Available We review the thermal properties of graphene, few-layer graphene and graphene nanoribbons, and discuss practical applications of graphene in thermal management and energy storage. The first part of the review describes the state-of-the-art in the graphene thermal field focusing on recently reported experimental and theoretical data for heat conduction in graphene and graphene nanoribbons. The effects of the sample size, shape, quality, strain distribution, isotope composition, and point-defect concentration are included in the summary. The second part of the review outlines thermal properties of graphene-enhanced phase change materials used in energy storage. It is shown that the use of liquid-phase-exfoliated graphene as filler material in phase change materials is promising for thermal management of high-power-density battery parks. The reported experimental and modeling results indicate that graphene has the potential to outperform metal nanoparticles, carbon nanotubes, and other carbon allotropes as filler in thermal management materials.

  11. Surfactant assisted surface morphology and thermal properties of polythiophene composites

    Science.gov (United States)

    Vijeth, H.; Niranjana, M.; Yesappa, L.; Chapi, Sharanappa; Raghu, S.; Ashokkumar, S. P.; Devendrappa, H.

    2017-06-01

    Conducting polythiophene (PTH)/aluminium oxide (Al2O3) composites was prepared with camphor sulphonic acid (CSA) as s anionic surfactant by means of in situ chemical oxidation polymerization. The morphology and material phase of PTH/Al2O3 (PTHA) composites were investigated by Field-Emission Scanning Electron Microscopy (FESEM) and Energy-dispersive X-ray spectroscopy (EDX). The FESEM image shows alter the size of grain and EDX results consistent with the presence of Al2O3 and CSA chemical composition. Thermal stability of composites was characterized using TGA/DSC, the results indicate that the PTP/Al2O3 composites have higher thermal stability than that of PTP and decompose at higher temperatures due to addition of anionic surfactant.

  12. Multilayer Microlaminated Ceramic Thermal Barrier Coating

    National Research Council Canada - National Science Library

    Yu, Charles

    1997-01-01

    .... Both thermal and mechanical characteristics of the coatings can be potentially optimized, and the coating will be more tolerant towards strain damage, have better thermal insulation and provide...

  13. High-G Thermal Characterization Centrifuge

    Data.gov (United States)

    Federal Laboratory Consortium — High-G testing of thermal components enables improved understanding of operating behavior under military-relevant environments. The High-G Thermal Characterization...

  14. A Thermal Switch for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Various planned NASA missions require thermal switches for active thermal control. As an example cryocoolers, including redundant coolers are incorporated on select...

  15. Thermal behaviour of Anopheles stephensi in response to infection with malaria and fungal entomopathogens

    Directory of Open Access Journals (Sweden)

    Read Andrew F

    2009-04-01

    Full Text Available Abstract Background Temperature is a critical determinant of the development of malaria parasites in mosquitoes, and hence the geographic distribution of malaria risk, but little is known about the thermal preferences of Anopheles. A number of other insects modify their thermal behaviour in response to infection. These alterations can be beneficial for the insect or for the infectious agent. Given current interest in developing fungal biopesticides for control of mosquitoes, Anopheles stephensi were examined to test whether mosquitoes showed thermally-mediated behaviour in response to infection with fungal entomopathogens and the rodent malaria, Plasmodium yoelii. Methods Over two experiments, groups of An. stephensi were infected with one of three entomopathogenic fungi, and/or P. yoelii. Infected and uninfected mosquitoes were released on to a thermal gradient (14 – 38°C for "snapshot" assessments of thermal preference during the first five days post-infection. Mosquito survival was monitored for eight days and, where appropriate, oocyst prevalence and intensity was assessed. Results and conclusion Both infected and uninfected An. stephensi showed a non-random distribution on the gradient, indicating some capacity to behaviourally thermoregulate. However, chosen resting temperatures were not altered by any of the infections. There is thus no evidence that thermally-mediated behaviours play a role in determining malaria prevalence or that they will influence the performance of fungal biopesticides against adult Anopheles.

  16. Thermal hydrolysis for sewage treatment: A critical review.

    Science.gov (United States)

    Barber, W P F

    2016-11-01

    A review concerning the development and applicability of sewage sludge thermal hydrolysis especially prior to anaerobic digestion is presented. Thermal hydrolysis has proven to be a successful approach to making sewage sludge more amenable to anaerobic digestion. Currently there are 75 facilities either in operation or planning, spanning several continents with the first installation in 1995. The reported benefits of thermal hydrolysis relate to: increased digestion loading rate due to altered rheological properties, improved biodegradation of (especially activated) sludge and enhanced dewaterability. In spite of its relative maturity, there has been no attempt to perform a critical review of the pertinent literature relating to the technology. Closer look at the literature reveals complications with comparing both experimental- and full-scale results due to differences in experimental set-up and capability, and also site-specific conditions at full-scale. Furthermore, it appears that understanding of thermodynamic and rheological properties of sludge is key to optimizing the process, however these parameters are largely overlooked by the literature. This paper aims to bridge these complexities in order to elucidate the benefits of thermal hydrolysis for sewage treatment, and makes recommendations for further development and research. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Reduction of thermal conductivity in phononic nanomesh structures

    KAUST Repository

    Yu, Jen-Kan

    2010-07-25

    Controlling the thermal conductivity of a material independently of its electrical conductivity continues to be a goal for researchers working on thermoelectric materials for use in energy applications1,2 and in the cooling of integrated circuits3. In principle, the thermal conductivity κ and the electrical conductivity σ may be independently optimized in semiconducting nanostructures because different length scales are associated with phonons (which carry heat) and electric charges (which carry current). Phonons are scattered at surfaces and interfaces, so κ generally decreases as the surface-to-volume ratio increases. In contrast, σ is less sensitive to a decrease in nanostructure size, although at sufficiently small sizes it will degrade through the scattering of charge carriers at interfaces. Here, we demonstrate an approach to independently controlling κ based on altering the phonon band structure of a semiconductor thin film through the formation of a phononic nanomesh film. These films are patterned with periodic spacings that are comparable to, or shorter than, the phonon mean free path. The nanomesh structure exhibits a substantially lower thermal conductivity than an equivalently prepared array of silicon nanowires, even though this array has a significantly higher surface-to-volume ratio. Bulk-like electrical conductivity is preserved. We suggest that this development is a step towards a coherent mechanism for lowering thermal conductivity. © 2010 Macmillan Publishers Limited. All rights reserved.

  18. Morphology and thermal conductivity of yttria-stabilized zirconia coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Hengbei [Materials Science Department, University of Virginia, Charlottesville, VA 22904 (United States)]. E-mail: hz5e@virginia.edu; Yu Fengling [Department of Mechanical and Environmental Engineering, University of California, Santa Barbara, CA 93106 (United States); Bennett, Ted D. [Department of Mechanical and Environmental Engineering, University of California, Santa Barbara, CA 93106 (United States); Wadley, Haydn N.G. [Materials Science Department, University of Virginia, Charlottesville, VA 22904 (United States)

    2006-11-15

    An electron beam directed vapor deposition method was used to grow 7 wt.% Y{sub 2}O{sub 3}-ZrO{sub 2} (7YSZ) coatings and the effects of substrate rotation upon the coating porosity, morphology, texture, and thermal conductivity were explored. As the rotation rate was increased, the texture changed from <1 1 1> to <1 0 0>. Under stationary deposition, the coatings were composed of straight columns, while low-frequency rotation resulted in wavy columns. Increases in rotation rate resulted in a gradual straightening and narrowing of the growth columns. The pore fraction slowly decreased as the rotation rate increased. The thermal conductivity was found to be inversely related to the pore fraction. The structural and thermal conductivity alterations are a result of changes to flux shadowing associated with specimen rotation in a gas jet-entrained vapor plume. The minimum thermal conductivity at a low rotation rate is 0.8 W/(m K), well below that of conventionally deposited coatings.

  19. Thermal analytical investigation of biopolymers and humic- and carbonaceous-based soil and sediment organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Lu Zhang; Eugene J. LeBoeuf; Baoshan Xing [Vanderbilt University, Nashville, TN (United States). Department of Civil and Environmental Engineering

    2007-07-15

    Improved understanding of the physical, chemical, and thermodynamic properties of soil and sediment organic matter (SOM) is crucial in elucidating sorption mechanisms of hydrophobic organic compounds (HOCs) in soils and sediments. In this study, several thermoanalytical techniques, including thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), temperature-modulated differential scanning calorimetry (TMDSC), and thermal mechanical analysis (TMA) were applied to 13 different organic materials (three woods, two humic acids, three kerogens, and five black carbons) representing a spectrum of diagenetic and/or thermal histories. Samples included Pocahontas No. 3 bituminous coal. Second-order thermal transition temperatures (T{sub t}) were identified in most materials, where the highest observed T{sub t} values (typically characterized as glass transition temperatures (T{sub g})) were shown to closely relate to chemical characteristics of the organic samples as influenced by diagenetic or thermal alteration. Results further suggest a positive correlation between glass transition temperature and a defined diagenetic/thermal index, where humic-based SOM (e.g., humic and fulvic acids) possess lower transition temperatures than more 'mature' carbonaceous-based SOM (i.e., kerogens and black carbons). The observed higher thermal transition temperature of aliphatic-rich Green River shale kerogen (about 120{sup o}C) relative to that of aromatic-rich humic acids suggests that a sole correlation of aromaticity to thermal transition temperature may be inappropriate. 55 refs., 2 figs., 1 tab.

  20. The Effect of Aqueous Alteration and Metamorphism in the Survival of Presolar Silicate Grains in Chondrites

    Science.gov (United States)

    Trigo-Rodriguez, Josep M.; Blum, Jürgen

    2009-09-01

    Relatively small amounts (typically between 2 and 200 ppm) of presolar grains have been preserved in the matrices of chondritic meteorites. The measured abundances of the different types of grains are highly variable from one chondrite to another, but are higher in unequilibrated chondrites that have experienced little or no aqueous alteration and/or metamorphic heating than in processed meteorites. A general overview of the abundances measured in presolar grains (particularly the recently identified presolar silicates) contained in primitive chondrites is presented. Here we will focus on the most primitive chondrite groups, as typically the highest measured abundances of presolar grains occur in primitive chondrites that have experienced little thermal metamorphism. Looking at the most aqueously altered chondrite groups, we find a clear pattern of decreasing abundance of presolar silicate grains with increasing levels of aqueous alteration. We conclude that measured abundances of presolar grains in altered chondrites are strongly biased by their peculiar histories. Scales quantifying the intensity of aqueous alteration and shock metamorphism in chondrites could correlate with the content of presolar silicates. To do this it would be required to infer the degree of destruction or homogenization of presolar grains in the matrices of primitive meteorites. To get an unbiased picture of the relative abundance of presolar grains in the different regions of the protoplanetary disk where first meteorites consolidated, future dedicated studies of primitive meteorites, IDPs, and collected materials from sample-return missions (like e.g. the planned Marco Polo) are urgently required.

  1. Distribution of buried hydrothermal alteration deduced from high-resolution magnetic surveys in Yellowstone National Park

    Science.gov (United States)

    Bouligand, Claire; Glen, Jonathan M. G.; Blakely, Richard J.

    2014-04-01

    Yellowstone National Park (YNP) displays numerous and extensive hydrothermal features. Although hydrothermal alteration in YNP has been extensively studied, the volume, geometry, and type of rock alteration at depth remain poorly constrained. In this study, we use high-resolution airborne and ground magnetic surveys and measurements of remanent and induced magnetization of field and drill core samples to provide constraints on the geometry of hydrothermal alteration within the subsurface of three thermal areas in YNP (Firehole River, Smoke Jumper Hot Springs, and Norris Geyser Basin). We observe that hydrothermal zones from both liquid- and vapor-dominated systems coincide with magnetic lows observed in aeromagnetic surveys and with a decrease of the amplitude of short-wavelength anomalies seen in ground magnetic surveys. This suggests a strong demagnetization of both the shallow and deep substratum within these areas associated with the removal of magnetic minerals by hydrothermal alteration processes. Such demagnetization is confirmed by measurements of rock samples from hydrothermal areas which display significantly decreased total magnetization. A pronounced negative anomaly is observed over the Lone Star Geyser and suggests a significant demagnetization of the substratum associated with areas displaying large-scale fluid flow. The ground and airborne magnetic surveys are used to evaluate the distribution of magnetization in the subsurface. This study shows that significant demagnetization occurs over a thickness of at least a few hundred meters in hydrothermal areas at YNP and that the maximum degree or maximum thickness of demagnetization correlates closely with the location of hydrothermal activity and mapped alteration.

  2. Thermal infrared exploration in the Carlin trend, northern Nevada

    Science.gov (United States)

    Watson, K.; Kruse, F.A.; Hummer-Miller, S.

    1990-01-01

    Experimental Thermal Infrared Multispectral Scanner (TIMS) aircraft data have been acquired for the Rodeo Creek NE 7 1/2 minute quadrangle, Eureka County, northern Nevada, covering the Carlin gold mine. A simple model has been developed to extract spectral emissivities for mapping surface lithology and alteration based on the physical properties of geologic materials. Emissivity-ratio images were prepared that allow generalized lithologic discrimination, identification of areas with high silica content, and the first reported detection of the carbonate secondary rest-strahlen feature. -from Authors

  3. Low thermal expansion glass ceramics

    CERN Document Server

    1995-01-01

    This book is one of a series reporting on international research and development activities conducted by the Schott group of companies With the series, Schott aims to provide an overview of its activities for scientists, engineers, and managers from all branches of industry worldwide where glasses and glass ceramics are of interest Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated This volume describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization Thus glass ceramics with thermal c...

  4. Advanced Spacecraft Thermal Modeling Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For spacecraft developers who spend millions to billions of dollars per unit and require 3 to 7 years to deploy, the LoadPath reduced-order (RO) modeling thermal...

  5. Thermal Conductivity of Foam Glass

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    Due to the increased focus on energy savings and waste recycling foam glass materials have gained increased attention. The production process of foam glass is a potential low-cost recycle option for challenging waste, e.g. CRT glass and industrial waste (fly ash and slags). Foam glass is used...... as thermal insulating material in building and chemical industry. The large volume of gas (porosity 90 – 95%) is the main reason of the low thermal conductivity of the foam glass. If gases with lower thermal conductivity compared to air are entrapped in the glass melt, the derived foam glass will contain...... only closed pores and its overall thermal conductivity will be much lower than that of the foam glass with open pores. In this work we have prepared foam glass using different types of recycled glasses and different kinds of foaming agents. This enabled the formation of foam glasses having gas cells...

  6. Hydrokinesitherapy in thermal mineral water

    Directory of Open Access Journals (Sweden)

    Rendulić-Slivar Senka

    2013-01-01

    Full Text Available The treatment of clients in health spa resorts entails various forms of hydrotherapy. Due to specific properties of water, especially thermal mineral waters, hydrokinesitherapy has a positive effect on the locomotor system, aerobic capabilities of organism and overall quality of human life. The effects of use of water in movement therapy are related to the physical and chemical properties of water. The application of hydrotherapy entails precautionary measures, with an individual approach in assessment and prescription. The benefits of treatment in thermal mineral water should be emphasized and protected, as all thermal mineral waters differ in composition. All physical properties of water are more pronounced in thermal mineral waters due to its mineralisation, hence its therapeutical efficiency is greater, as well.

  7. National Solar Thermal Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The National Solar Thermal Test Facility (NSTTF) is the only test facility in the United States of its type. This unique facility provides experimental engineering...

  8. Thermal transport in fractal systems

    DEFF Research Database (Denmark)

    Kjems, Jørgen

    1992-01-01

    Recent experiments on the thermal transport in systems with partial fractal geometry, silica aerogels, are reviewed. The individual contributions from phonons, fractons and particle modes, respectively, have been identified and can be described by quantitative models consistent with heat capacity...

  9. Thermal biology of domestic animals.

    Science.gov (United States)

    Collier, Robert J; Gebremedhin, Kifle G

    2015-01-01

    The thermal environment is the most important ecological factor determining the growth, development, and productivity of domestic animals. Routes of energy exchange (sensible heat and latent heat) between animals and their environment are greatly influenced by body weight, fat deposition, hair-coat properties, functional activity, and number of sweat glands, as well as the presence or absence of anatomical respiratory countercurrent heat exchange capability. Differences in these anatomical features across species have led to specialization of heat exchange. Thermal plasticity and degree of acclimation are critical factors determining the ability of animals to respond to environmental change. Increases in productive capability of domestic animals can compromise thermal acclimation and plasticity, requiring greater investments in housing systems that reduce variability of the thermal environment. The combination of steadily increasing metabolic heat production as domestic animal productivity increases and a rising world temperature poses ongoing and future challenges to maintaining health and well-being of domestic animals.

  10. Alternate Propellant Thermal Rocket Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Alternate Propellant Thermal Rocket (APTR) is a novel concept for propulsion of space exploration or orbit transfer vehicles. APTR propulsion is provided by...

  11. Ablative Thermal Protection System Fundamentals

    Science.gov (United States)

    Beck, Robin A. S.

    2013-01-01

    This is the presentation for a short course on the fundamentals of ablative thermal protection systems. It covers the definition of ablation, description of ablative materials, how they work, how to analyze them and how to model them.

  12. Industrial applications of thermal plasmas

    Science.gov (United States)

    Szente, Roberto Nunes

    1995-09-01

    The main characteristics and applications of thermal plasmas are reviewed here. The industrial applications of thermal plasmas can be divided in: low power-cutting, welding, spraying; metallurgical and steelmaking; materials; environment. Some of the processes described in this article include: powder spraying, metal refining, tundish and laddle heating, production of ferroalloys and ceramic materials, and treatment of residues (aluminum scrap, steel dusts, ashes, hospital wastes, electroplating mud). The use of thermal plasmas in the environment arena in particular has attracted increasingly attention as the regulations for disposal of residues become tougher. More research and development is needed particularly for decreasing the erosion of the electrodes of plasma torches and fundamental understanding of high temperature chemistry, heat transfer, and electric arcs for broadening the applications of thermal plasmas.

  13. Thermal lensing in ocular media

    Science.gov (United States)

    Vincelette, Rebecca Lee

    2009-12-01

    This research was a collaborative effort between the Air Force Research Laboratory (AFRL) and the University of Texas to examine the laser-tissue interaction of thermal lensing induced by continuous-wave, CW, near-infrared, NIR, laser radiation in the eye and its influence on the formation of a retinal lesion from said radiation. CW NIR laser radiation can lead to a thermal lesion induced on the retina given sufficient power and exposure duration as related to three basic parameters; the percent of transmitted energy to, the optical absorption of, and the size of the laser-beam created at the retina. Thermal lensing is a well-known phenomenon arising from the optical absorption, and subsequent temperature rise, along the path of the propagating beam through a medium. Thermal lensing causes the laser-beam profile delivered to the retina to be time dependent. Analysis of a dual-beam, multidimensional, high-frame rate, confocal imaging system in an artificial eye determined the rate of thermal lensing in aqueous media exposed to 1110, 1130, 1150 and 1318-nm wavelengths was related to the power density created along the optical axis and linear absorption coefficient of the medium. An adaptive optics imaging system was used to record the aberrations induced by the thermal lens at the retina in an artificial eye during steady-state. Though the laser-beam profiles changed over the exposure time, the CW NIR retinal damage thresholds between 1110--1319-nm were determined to follow conventional fitting algorithms which neglected thermal lensing. A first-order mathematical model of thermal lensing was developed by conjoining an ABCD beam propagation method, Beer's law of attenuation, and a solution to the heat-equation with respect to radial diffusion. The model predicted that thermal lensing would be strongest for small (retina. The model predicted thermal lensing would cause the retinal damage threshold for wavelengths above 1300-nm to increase with decreasing beam

  14. Thermal Expansion of Polyurethane Foam

    Science.gov (United States)

    Lerch, Bradley A.; Sullivan, Roy M.

    2006-01-01

    Closed cell foams are often used for thermal insulation. In the case of the Space Shuttle, the External Tank uses several thermal protection systems to maintain the temperature of the cryogenic fuels. A few of these systems are polyurethane, closed cell foams. In an attempt to better understand the foam behavior on the tank, we are in the process of developing and improving thermal-mechanical models for the foams. These models will start at the microstructural level and progress to the overall structural behavior of the foams on the tank. One of the key properties for model characterization and verification is thermal expansion. Since the foam is not a material, but a structure, the modeling of the expansion is complex. It is also exacerbated by the anisoptropy of the material. During the spraying and foaming process, the cells become elongated in the rise direction and this imparts different properties in the rise direction than in the transverse directions. Our approach is to treat the foam as a two part structure consisting of the polymeric cell structure and the gas inside the cells. The polymeric skeleton has a thermal expansion of its own which is derived from the basic polymer chemistry. However, a major contributor to the thermal expansion is the volume change associated with the gas inside of the closed cells. As this gas expands it exerts pressure on the cell walls and changes the shape and size of the cells. The amount that this occurs depends on the elastic and viscoplastic properties of the polymer skeleton. The more compliant the polymeric skeleton, the more influence the gas pressure has on the expansion. An additional influence on the expansion process is that the polymeric skeleton begins to breakdown at elevated temperatures and releases additional gas species into the cell interiors, adding to the gas pressure. The fact that this is such a complex process makes thermal expansion ideal for testing the models. This report focuses on the thermal

  15. Tasco®, a Product of Ascophyllum nodosum, Imparts Thermal Stress Tolerance in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Franklin Evans

    2011-11-01

    Full Text Available Tasco®, a commercial product manufactured from the brown alga Ascophyllum nodosum, has been shown to impart thermal stress tolerance in animals. We investigated the physiological, biochemical and molecular bases of this induced thermal stress tolerance using the invertebrate animal model, Caenorhabiditis elegans. Tasco® water extract (TWE at 300 µg/mL significantly enhanced thermal stress tolerance as well as extended the life span of C. elegans. The mean survival rate of the model animals under thermal stress (35 °C treated with 300 µg/mL and 600 µg/mL TWE, respectively, was 68% and 71% higher than the control animals. However, the TWE treatments did not affect the nematode body length, fertility or the cellular localization of daf-16. On the contrary, TWE under thermal stress significantly increased the pharyngeal pumping rate in treated animals compared to the control. Treatment with TWE also showed differential protein expression profiles over control following 2D gel-electrophoresis analysis. Furthermore, TWE significantly altered the expression of at least 40 proteins under thermal stress; among these proteins 34 were up-regulated while six were down-regulated. Mass spectroscopy analysis of the proteins altered by TWE treatment revealed that these proteins were related to heat stress tolerance, energy metabolism and a muscle structure related protein. Among them heat shock proteins, superoxide dismutase, glutathione peroxidase, aldehyde dehydrogenase, saposin-like proteins 20, myosin regulatory light chain 1, cytochrome c oxidase RAS-like, GTP-binding protein RHO A, OS were significantly up-regulated, while eukaryotic translation initiation factor 5A-1 OS, 60S ribosomal protein L18 OS, peroxiredoxin protein 2 were down regulated by TWE treatment. These results were further validated by gene expression and reporter gene expression analyses. Overall results indicate that the water soluble components of Tasco® imparted thermal stress

  16. Thermally activated technologies: Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2003-05-01

    The purpose of this Technology Roadmap is to outline a set of actions for government and industry to develop thermally activated technologies for converting America’s wasted heat resources into a reservoir of pollution-free energy for electric power, heating, cooling, refrigeration, and humidity control. Fuel flexibility is important. The actions also cover thermally activated technologies that use fossil fuels, biomass, and ultimately hydrogen, along with waste heat.

  17. Contamination Control for Thermal Engineers

    Science.gov (United States)

    Rivera, Rachel B.

    2015-01-01

    The presentation will be given at the 26th Annual Thermal Fluids Analysis Workshop (TFAWS 2015) hosted by the Goddard Spaceflight Center (GSFC) Thermal Engineering Branch (Code 545). This course will cover the basics of Contamination Control, including contamination control related failures, the effects of contamination on Flight Hardware, what contamination requirements translate to, design methodology, and implementing contamination control into Integration, Testing and Launch.

  18. Thermal measurements and inverse techniques

    CERN Document Server

    Orlande, Helcio RB; Maillet, Denis; Cotta, Renato M

    2011-01-01

    With its uncommon presentation of instructional material regarding mathematical modeling, measurements, and solution of inverse problems, Thermal Measurements and Inverse Techniques is a one-stop reference for those dealing with various aspects of heat transfer. Progress in mathematical modeling of complex industrial and environmental systems has enabled numerical simulations of most physical phenomena. In addition, recent advances in thermal instrumentation and heat transfer modeling have improved experimental procedures and indirect measurements for heat transfer research of both natural phe

  19. Thermal Resonance in Signal Transmission

    OpenAIRE

    Reigada Sanz, Ramon; Sarmiento, Antonio; Lindenberg, Katja

    2001-01-01

    We use temperature tuning to control signal propagation in simple one-dimensional arrays of masses connected by hard anharmonic springs and with no local potentials. In our numerical model a sustained signal is applied at one site of a chain immersed in a thermal environment and the signal-to-noise ratio is measured at each oscillator. We show that raising the temperature can lead to enhanced signal propagation along the chain, resulting in thermal resonance effects akin to the resonance obse...

  20. Thermal Conductivity of Diamond Composites

    OpenAIRE

    Fedor M. Shakhov; Kidalov, Sergey V.

    2009-01-01

    A major problem challenging specialists in present-day materials sciences is the development of compact, cheap to fabricate heat sinks for electronic devices, primarily for computer processors, semiconductor lasers, high-power microchips, and electronics components. The materials currently used for heat sinks of such devices are aluminum and copper, with thermal conductivities of about 250 W/(m·K) and 400 W/(m·K), respectively. Significantly, the thermal expansion coefficient of metals differ...

  1. Thermal dehydration kinetics of phosphogypsum

    OpenAIRE

    López, F. A.; Tayibi, H.; García-Díaz, I.; Alguacil, F. J.

    2015-01-01

    Phsophogypsum is a by-product from the processing phosphate rock. Before the use of it in cement industry such as setting regulator is necessary a study of dehydration reaction of phosphogypsum to avoid the false setting during the milling. The aim is to study the thermal behavior of two different phosphogypsum sources (Spain and Tunisia) under non-isothermal conditions in argon atmosphere by using Thermo-Gravimetriy, Differential Thermal Analysis (TG-DTA) and Differential Scanning Calori...

  2. Power Electronics Thermal Control (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Narumanchi, S.

    2010-05-05

    Thermal management plays an important part in the cost of electric drives in terms of power electronics packaging. Very promising results have been obtained by using microporous coatings and skived surfaces in conjunction with single-phase and two-phase flows. Sintered materials and thermoplastics with embedded fibers show significant promise as thermal interface materials, or TIMs. Appropriate cooling technologies depend on the power electronics package application and reliability.

  3. Cerebrospinal fluid space alterations in melancholic depression.

    Directory of Open Access Journals (Sweden)

    Esther Via

    Full Text Available Melancholic depression is a biologically homogeneous clinical entity in which structural brain alterations have been described. Interestingly, reports of structural alterations in melancholia include volume increases in Cerebro-Spinal Fluid (CSF spaces. However, there are no previous reports of CSF volume alterations using automated whole-brain voxel-wise approaches, as tissue classification algorithms have been traditionally regarded as less reliable for CSF segmentation. Here we aimed to assess CSF volumetric alterations in melancholic depression and their clinical correlates by means of a novel segmentation algorithm ('new segment', as implemented in the software Statistical Parametric Mapping-SPM8, incorporating specific features that may improve CSF segmentation. A three-dimensional Magnetic Resonance Image (MRI was obtained from seventy patients with melancholic depression and forty healthy control subjects. Although imaging data were pre-processed with the 'new segment' algorithm, in order to obtain a comparison with previous segmentation approaches, tissue segmentation was also performed with the 'unified segmentation' approach. Melancholic patients showed a CSF volume increase in the region of the left Sylvian fissure, and a CSF volume decrease in the subarachnoid spaces surrounding medial and lateral parietal cortices. Furthermore, CSF increases in the left Sylvian fissure were negatively correlated with the reduction percentage of depressive symptoms at discharge. None of these results were replicated with the 'unified segmentation' approach. By contrast, between-group differences in the left Sylvian fissure were replicated with a non-automated quantification of the CSF content of this region. Left Sylvian fissure alterations reported here are in agreement with previous findings from non-automated CSF assessments, and also with other reports of gray and white matter insular alterations in depressive samples using automated approaches

  4. Thermal conductivity of US coals

    Energy Technology Data Exchange (ETDEWEB)

    Herrin, J.M.; Deming, D. [University of Oklahoma, Norman, OK (United States). School of Geology and Geophysics

    1996-11-10

    Coal samples in the form of randomly oriented aggregates were obtained from the Pennsylvania State University Coal Bank for the purpose of thermal conductivity measurements. Samples represented 55 locations from throughout the United States and included 6 lignites, 10 subbituminous coals, 36 bituminous coals, and 3 anthracite samples. Matrix thermal conductivities measured at 22{degree}C in the laboratory ranged from 0.22 to 0.55 W/m degree K, with an arithmetic mean of 0.33 W/m degrees K and a standard deviation of 0.07 W/m degrees K. The thermal conductivity of lignites, subbituminous, and bituminous coals is controlled by composition and can be predicted by a three-component (Moisture, ash, and carbon + volatiles) geometric mean model with a rns residual of 6.1%. The thermal conductivity of bituminous and anthracite samples was found to be positively correlated with matrix density. With the exception of three anthracite samples, rank was not correlated with thermal conductivity nor was the ratio of carbon to volatiles. The relatively high thermal conductivity of three anthracite samples (mean of 0.49 W/m degrees K) may have been related to graphitization.

  5. [Thermal diffusivity of dental cements].

    Science.gov (United States)

    Paroussis, D; Kakaboura, A; Chrysafidis, C; Mauroyiannakis, E

    1990-08-01

    Thermal insulative efficiency, is one of the desirable properties of the dental cements. In this study, the thermal diffusivity of three types of dental cements, were measured. Thermal diffusivity was determined by the following method. Two thermo-couples were used and connected to a chart record, the first was embedded in the cylindrical block of the cement specimen and the other in a mixing of ice and water (reference thermocouple). All them were set in a apparatus consisting of a double cooling bath. Calculation of thermal diffusivity were based on the curve provided of the record during cooling of the cement and a theoretical mathematic model. Values were ranged from 2,985 to 3,934 cm2.sec-1. ZOE cement exhibited the highest value, the glass-ionomers the lowest and the poly-carboxylates were average. The results showed that the thermal diffusivity of the cements is dependent from the type of the cement but the differences between them were not statistically significant. Additionally, the values obtained were about the same as the dentin, so the dental cements may consider as good thermal insulators.

  6. Thermally stable imaging channeled spectropolarimetry

    Science.gov (United States)

    Craven-Jones, Julia; Way, Brandyn M.; Hunt, Jeff; Kudenov, Michael W.; Mercier, Jeffrey A.

    2013-09-01

    Channeled spectropolarimetry can measure the complete polarization state of light as a function of wavelength. Typically, a channeled spectropolarimeter uses high order retarders made of uniaxial crystal to amplitude modulate the measured spectrum with the spectrally-dependent Stokes polarization information. A primary limitation of conventional channeled spectropolarimeters is related to the thermal variability of the retarders. Thermal variation often forces frequent system recalibration, particularly for field deployed systems. However, implementing thermally stable retarders results in an athermal channeled spectropolarimeter that relieves the need for frequent recalibration. Past work has addressed this issue by developing athermalized retarders using two or more uniaxial crystals. Recently, a retarder made of biaxial KTP and cut at a thermally insensitive angle was used to produce an athermal channeled spectropolarimeter. This paper presents the results of the biaxial crystal system and compares the two thermal stabilization techniques in the context of producing an imaging thermally stable channeled spectropolarimeter. A preliminary design for a snapshot imaging channeled spectropolarimeter is also presented.

  7. Composite Thermal Switch

    Science.gov (United States)

    McDonald, Robert; Brawn, Shelly; Harrison, Katherine; O'Toole, Shannon; Moeller, Michael

    2011-01-01

    Lithium primary and lithium ion secondary batteries provide high specific energy and energy density. The use of these batteries also helps to reduce launch weight. Both primary and secondary cells can be packaged as high-rate cells, which can present a threat to crew and equipment in the event of external or internal short circuits. Overheating of the cell interior from high current flows induced by short circuits can result in exothermic reactions in lithium primary cells and fully charged lithium ion secondary cells. Venting of the cell case, ejection of cell components, and fire have been reported in both types of cells, resulting from abuse, cell imperfections, or faulty electronic control design. A switch has been developed that consists of a thin layer of composite material made from nanoscale particles of nickel and Teflon that conducts electrons at room temperature and switches to an insulator at an elevated temperature, thus interrupting current flow to prevent thermal runaway caused by internal short circuits. The material is placed within the cell, as a thin layer incorporated within the anode and/or the cathode, to control excess currents from metal-to-metal or metal-to-carbon shorts that might result from cell crush or a manufacturing defect. The safety of high-rate cells is thus improved, preventing serious injury to personnel and sensitive equipment located near the battery. The use of recently available nanoscale particles of nickel and Teflon permits an improved, homogeneous material with the potential to be fine-tuned to a unique switch temperature, sufficiently below the onset of a catastrophic chemical reaction. The smaller particles also permit the formation of a thinner control film layer (switch (CTS(TradeMark)) coating can be incorporated in either the anode or cathode or both. The coating can be applied in a variety of different processes that permits incorporation in the cell and electrode manufacturing processes. The CTS responds quickly

  8. Petroleum alteration by thermochemical sulfate reduction - A comprehensive molecular study of aromatic hydrocarbons and polar compounds

    Science.gov (United States)

    Walters, Clifford C.; Wang, Frank C.; Qian, Kuangnan; Wu, Chunping; Mennito, Anthony S.; Wei, Zhibin

    2015-03-01

    Thermochemical sulfate reduction (TSR) alters petroleum composition as it proceeds towards the complete oxidation of hydrocarbons to CO2. The effects of TSR on the molecular and isotopic composition of volatile species are well known; however, the non-volatile higher molecular weight aromatic and polar species have not been well documented. To address this deficiency, a suite of onshore Gulf coast oils and condensates generated from and accumulating in Smackover carbonates was assembled to include samples that experienced varying levels of TSR alteration and in reservoir thermal cracking. The entire molecular composition of aromatic hydrocarbons and NSO species were characterized and semi-quantified using comprehensive GC × GC (FID and CSD) and APPI-FTICR-MS. The concentration of thiadiamondoids is a reliable indicator of the extent of TSR alteration. Once generated by TSR, thiadiamondoids remain thermally stable in all but the most extreme reservoir temperatures (>180 °C). Hydrocarbon concentrations and distributions are influenced by thermal cracking and TSR. With increasing TSR alteration, oils become enriched in monoaromatic hydrocarbons and the distribution of high molecular weight aromatic hydrocarbons shifts towards more condensed species with a decrease in the number of alkyl carbons. Organosulfur compounds are created by the TSR process. In addition to the increase in benzothiophenes and dibenzothiophenes noted in previous studies, TSR generates condensed species containing one or more sulfur atoms that likely are composed of a single or multiple thiophenic cores. We hypothesize that these species are generated from the partial oxidation of PAHs and dealkylation reactions, followed by sulfur incorporation and condensation reactions. The organosulfur species remaining in the TSR altered oils are "proto-solid bitumen" moieties that upon further condensation, oxidation or sulfur incorporation result in highly sulfur enriched solid bitumen, which is

  9. Influence of Picual olive ripening on virgin olive oil alteration and stability during potato frying.

    Science.gov (United States)

    Olivero-David, Raul; Mena, Carmen; Pérez-Jimenez, M Angeles; Sastre, Blanca; Bastida, Sara; Márquez-Ruiz, Gloria; Sánchez-Muniz, Francisco J

    2014-12-03

    Ripening modifies oil attributes and composition. However, the influence of olive ripening on virgin olive oil (VOO) thermal oxidative stability on food-frying has not been studied yet. Oils from Picual olives of low (VOO1), medium (VOO2), and high (VOO3) ripeness were obtained, and their thermal oxidative stability during 40 potato-fryings was tested. Unused VOO1 showed higher antioxidant content and oxidative stability than VOO2 and VOO3. Polar compounds (PC), oligomers, and altered fatty acid methyl esters (polar-FAME) increased, whereas linoleic acid, polyphenols, and tocopherols decreased in the three VOOs through frying. The alteration was lower in VOO1, followed by VOO2 (0.105, 0.117, and 0.042 g/100 g oil less of PC, oligomers and polar-FAME per frying, respectively, in VOO1 than in VOO3). In conclusion, VOO obtained from low-ripeness Picual olives should be preferred when frying fresh-potatoes due to its higher thermal and oxidative stability, permitting a higher number of potato-frying uses.

  10. Thermal History Devices, Systems For Thermal History Detection, And Methods For Thermal History Detection

    KAUST Repository

    Caraveo Frescas, Jesus Alfonso

    2015-05-28

    Embodiments of the present disclosure include nanowire field-effect transistors, systems for temperature history detection, methods for thermal history detection, a matrix of field effect transistors, and the like.

  11. Folding Elastic Thermal Surface - FETS

    Science.gov (United States)

    Urquiza, Eugenio; Zhang, Burt X.; Thelen, Michael P.; Rodriquez, Jose I.; Pellegrino, Sergio

    2013-01-01

    The FETS is a light and compact thermal surface (sun shade, IR thermal shield, cover, and/or deployable radiator) that is mounted on a set of offset tape-spring hinges. The thermal surface is constrained during launch and activated in space by a thermomechanical latch such as a wax actuator. An application-specific embodiment of this technology developed for the MATMOS (Mars Atmospheric Trace Molecule Occultation Spectrometer) project serves as a deployable cover and thermal shield for its passive cooler. The FETS fits compactly against the instrument within the constrained launch envelope, and then unfolds into a larger area once in space. In this application, the FETS protects the passive cooler from thermal damage and contamination during ground operations, launch, and during orbit insertion. Once unfolded or deployed, the FETS serves as a heat shield, intercepting parasitic heat loads by blocking the passive cooler s view of the warm spacecraft. The technology significantly enhances the capabilities of instruments requiring either active or passive cooling of optical detectors. This can be particularly important for instruments where performance is limited by the available radiator area. Examples would be IR optical instruments on CubeSATs or those launched as hosted payloads because radiator area is limited and views are often undesirable. As a deployable radiator, the panels making up the FETS are linked thermally by thermal straps and heat pipes; the structural support and deployment energy is provided using tape-spring hinges. The FETS is a novel combination of existing technologies. Prior art for deployable heat shields uses rotating hinges that typically must be lubricated to avoid cold welding or static friction. By using tape-spring hinges, the FETS avoids the need for lubricants by avoiding friction altogether. This also eliminates the potential for contamination of nearby cooled optics by outgassing lubricants. Furthermore, the tape-spring design of

  12. Thermal Conductivity of Diamond Composites

    Science.gov (United States)

    Kidalov, Sergey V.; Shakhov, Fedor M.

    2009-01-01

    A major problem challenging specialists in present-day materials sciences is the development of compact, cheap to fabricate heat sinks for electronic devices, primarily for computer processors, semiconductor lasers, high-power microchips, and electronics components. The materials currently used for heat sinks of such devices are aluminum and copper, with thermal conductivities of about 250 W/(m·K) and 400 W/(m·K), respectively. Significantly, the thermal expansion coefficient of metals differs markedly from those of the materials employed in semiconductor electronics (mostly silicon); one should add here the low electrical resistivity metals possess. By contrast, natural single-crystal diamond is known to feature the highest thermal conductivity of all the bulk materials studied thus far, as high as 2,200 W/(m·K). Needless to say, it cannot be applied in heat removal technology because of high cost. Recently, SiC- and AlN-based ceramics have started enjoying wide use as heat sink materials; the thermal conductivity of such composites, however, is inferior to that of metals by nearly a factor two. This prompts a challenging scientific problem to develop diamond-based composites with thermal characteristics superior to those of aluminum and copper, adjustable thermal expansion coefficient, low electrical conductivity and a moderate cost, below that of the natural single-crystal diamond. The present review addresses this problem and appraises the results reached by now in studying the possibility of developing composites in diamond-containing systems with a view of obtaining materials with a high thermal conductivity.

  13. Thermal Conductivity of Diamond Composites

    Directory of Open Access Journals (Sweden)

    Fedor M. Shakhov

    2009-12-01

    Full Text Available A major problem challenging specialists in present-day materials sciences is the development of compact, cheap to fabricate heat sinks for electronic devices, primarily for computer processors, semiconductor lasers, high-power microchips, and electronics components. The materials currently used for heat sinks of such devices are aluminum and copper, with thermal conductivities of about 250 W/(m·K and 400 W/(m·K, respectively. Significantly, the thermal expansion coefficient of metals differs markedly from those of the materials employed in semiconductor electronics (mostly silicon; one should add here the low electrical resistivity metals possess. By contrast, natural single-crystal diamond is known to feature the highest thermal conductivity of all the bulk materials studied thus far, as high as 2,200 W/(m·K. Needless to say, it cannot be applied in heat removal technology because of high cost. Recently, SiC- and AlN-based ceramics have started enjoying wide use as heat sink materials; the thermal conductivity of such composites, however, is inferior to that of metals by nearly a factor two. This prompts a challenging scientific problem to develop diamond-based composites with thermal characteristics superior to those of aluminum and copper, adjustable thermal expansion coefficient, low electrical conductivity and a moderate cost, below that of the natural single-crystal diamond. The present review addresses this problem and appraises the results reached by now in studying the possibility of developing composites in diamond-containing systems with a view of obtaining materials with a high thermal conductivity.

  14. Alterations in physiology and anatomy during pregnancy.

    Science.gov (United States)

    Tan, Eng Kien; Tan, Eng Loy

    2013-12-01

    Pregnant women undergo profound anatomical and physiological changes so that they can cope with the increased physical and metabolic demands of their pregnancies. The cardiovascular, respiratory, haematological, renal, gastrointestinal and endocrine systems all undergo important physiological alterations and adaptations needed to allow development of the fetus and to allow the mother and fetus to survive the demands of childbirth. Such alterations in anatomy and physiology may cause difficulties in interpreting signs, symptoms, and biochemical investigations, making the clinical assessment of a pregnant woman inevitably confusing but challenging. Understanding these changes is important for every practicing obstetrician, as the pathological deviations from the normal physiological alterations may not be clear-cut until an adverse outcome has resulted. Only with a sound knowledge of the physiology and anatomy changes can the care of an obstetric parturient be safely optimized for a better maternal and fetal outcome. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Inflammation and Immune System Alterations in Frailty

    Science.gov (United States)

    Yao, Xu; Li, Huifen; Leng, Sean X.

    2010-01-01

    SYNOPSIS Frailty is an important geriatric syndrome characterized by multi-system dysregulation. Substantial evidence suggests heightened inflammatory state and significant immune system alterations in frailty. A heightened inflammatory state is marked by increases in levels of inflammatory molecules (IL-6 and CRP) and counts of white blood cell and its subpopulations, which may play an important role in the pathogenesis of frailty, directly or through its detrimental influence to other physiologic systems. Alterations in the innate immune system include decreased proliferation of the peripheral blood mononuclear cells (PBMCs) and upregulated monocytic expression of specific stress responsive inflammatory pathway genes. In the adaptive immune system, while little information is available about potential B-cell changes, significant alterations have been identified in the T-cell compartment including increased counts of CD8+, CD8+CD28−, CCR5+ T cells, above and beyond age-related senescent immune remodeling. PMID:21093724

  16. Alter(n – ein vielschichtiger Begriff

    Directory of Open Access Journals (Sweden)

    Nicole Maly-Lukas

    2005-07-01

    Full Text Available Diese Veröffentlichung, die aus einer Vortragsreihe an der katholischen Fachhochschule Freiburg entstanden ist, führt die Leserinnen und Leser in die verschiedenen Sichtweisen des Alter(ns in der modernen Gesellschaft ein. Es handelt sich um eine gelungene Zusammenstellung von Beiträgen aus unterschiedlichen Disziplinen, die sich alle aus ihrer Sicht dem Thema Alter(n widmen. Die einzelnen Artikel sind zwischen 8 und 38 Seiten lang und recht schnell und einfach zu lesen. Je nach Hintergrund und Interessen werden die einzelnen Leserinnen und Leser dabei sicher unterschiedliche Beiträge favorisieren. Schade ist nur, dass durch die ungleichen Längen der Beiträge bestimmte thematische Schwerpunkte – ob gewollt oder nicht – gesetzt werden. Dies sollte die Leserinnen und Leser, die offen für unterschiedlichste Sichtweisen des Alter(ns sind, jedoch nicht davon abhalten, dieses Buch zu lesen.

  17. Metabolic Alterations in Renal and Prostate Cancer.

    Science.gov (United States)

    Ciccarese, Chiara; Santoni, Matteo; Massari, Francesco; Modena, Alessandra; Piva, Francesco; Conti, Alessandro; Mazzucchelli, Roberta; Cheng, Liang; Lopez-Beltran, Antonio; Scarpelli, Marina; Tortora, Giampaolo; Montironi, Rodolfo

    2016-01-01

    Cancer metabolism is emerging as a promising research area in genitourinary tumors. Both renal cell carcinoma (RCC) and prostate cancer (PCa) cells exhibit marked alterations of their metabolism. These changes include increased aerobic glycolysis (the Warburg effect), increased protein and DNA synthesis and de novo fatty acid (FA) synthesis. Understanding the molecular mechanisms underlying such alterations will represent a major step forward in cancer research. Indeed, reprogramming cancer cell energy metabolism represents a promising hallmark of cancer and may pave the way for novel personalized approaches. PubMed databases were searched for articles published about cancer metabolism in genitourinary tumors. This review is focused on the metabolic alterations that occur in RCC and PCa and describes the mechanisms underlying such metabolic changes.

  18. Public health implications of altered puberty timing

    DEFF Research Database (Denmark)

    Golub, M.S.; Collman, G.W.; Foster, P.M.

    2008-01-01

    Changes in puberty timing have implications for the treatment of individual children, for the risk of later adult disease, and for chemical testing and risk assessment for the population. Children with early puberty are at a risk for accelerated skeletal maturation and short adult height, early...... sexual debut, potential sexual abuse, and psychosocial difficulties. Altered puberty timing is also of concern for the development of reproductive tract cancers later in life. For example, an early age of menarche is a risk factor for breast cancer. A low age at male puberty is associated....... Altered timing of puberty also has implications for behavioral disorders. For example, an early maturation is associated with a greater incidence of conduct and behavior disorders during adolescence. Finally, altered puberty timing is considered an adverse effect in reproductive toxicity risk assessment...

  19. Streamflow alteration at selected sites in Kansas

    Science.gov (United States)

    Juracek, Kyle E.; Eng, Ken

    2017-06-26

    An understanding of streamflow alteration in response to various disturbances is necessary for the effective management of stream habitat for a variety of species in Kansas. Streamflow alteration can have negative ecological effects. Using a modeling approach, streamflow alteration was assessed for 129 selected U.S. Geological Survey streamgages in the State for which requisite streamflow and basin-characteristic information was available. The assessment involved a comparison of the observed condition from 1980 to 2015 with the predicted expected (least-disturbed) condition for 29 streamflow metrics. The metrics represent various characteristics of streamflow including average flow (annual, monthly) and low and high flow (frequency, duration, magnitude).Streamflow alteration in Kansas was indicated locally, regionally, and statewide. Given the absence of a pronounced trend in annual precipitation in Kansas, a precipitation-related explanation for streamflow alteration was not supported. Thus, the likely explanation for streamflow alteration was human activity. Locally, a flashier flow regime (typified by shorter lag times and more frequent and higher peak discharges) was indicated for three streamgages with urbanized basins that had higher percentages of impervious surfaces than other basins in the State. The combination of localized reservoir effects and regional groundwater pumping from the High Plains aquifer likely was responsible, in part, for diminished conditions indicated for multiple streamflow metrics in western and central Kansas. Statewide, the implementation of agricultural land-management practices to reduce runoff may have been responsible, in part, for a diminished duration and magnitude of high flows. In central and eastern Kansas, implemented agricultural land-management practices may have been partly responsible for an inflated magnitude of low flows at several sites.

  20. Sensorimotor incongruence alters limb perception and movement.

    Science.gov (United States)

    Osumi, Michihiro; Nobusako, Satoshi; Zama, Takuro; Taniguchi, Megumi; Shimada, Sotaro; Morioka, Shu

    2017-09-21

    Altered limb ownership or heaviness has been observed in patients with hemiplegia, chronic pain, and several other conditions. Although these sensations are thought to be caused by sensorimotor incongruence, few studies have systematically verified this relationship. In addition, it remains unclear whether these subjective sensations affect movement execution. In a psychophysical experiment, we systematically investigated the relationships between sensorimotor integration and subjective limb perception, such as sense of ownership/heaviness, and verified the relationship between subjective limb perception and movement execution. Thirty-nine healthy participants were enrolled, and a visual feedback delay system was used to systematically evoke sensorimotor incongruence. Participants periodically flexed and extended their wrist while seeing a delayed image of their hand under five delay conditions (0, 150, 250, 350, 600ms). During wrist movement, electromyography (EMG) activity in flexor carpi radialis (FCR) was recorded. Also, to analyze the change in muscle activity and movement speed, the values of integral and peak frequency were calculated. To record changes in the subjective limb perception of the altered limb ownership and heaviness, we used a 7-point Likert scale for each participant. We found that altered ownership and heaviness increased with increasing feedback delay. Also, muscle activity and movement speed decreased with visual feedback delay. There was no significant correlation between subjective altered limb perception (i.e., altered limb ownership and heaviness) and muscle activity or movement speed. We systematically demonstrated that limb ownership, heaviness, muscle activation and movement speed were altered by sensorimotor incongruence. However, our study did not reveal the relationships between these factors. These results indicate the existence of different mechanisms governing subjective limb perception and movement execution. In the future, we

  1. Diet alters species recognition in juvenile toads.

    Science.gov (United States)

    Pfennig, Karin S; Rodriguez Moncalvo, Verónica G; Burmeister, Sabrina S

    2013-10-23

    Whether environmental effects during juvenile development can alter the ontogeny of adult mating behaviour remains largely unexplored. We evaluated the effect of diet on the early expression of conspecific recognition in spadefoot toads, Spea bombifrons. We found that juvenile toads display phonotaxis behaviour six weeks post-metamorphosis. However, preference for conspecifics versus heterospecifics emerged later and was diet dependent. Thus, the environment can affect the early development of species recognition in a way that might alter adult behaviour. Evaluating such effects is important for understanding variation in hybridization between species and the nature of species boundaries.

  2. White matter alterations in temporal lobe epilepsy

    Science.gov (United States)

    Diniz, P. B.; Salmon, C. E.; Velasco, T. R.; Sakamoto, A. C.; Leite, J. P.; Santos, A. C.

    2011-03-01

    In This study, we used Fractional anisotropy (FA), mean diffusivity (D), parallel diffusivity (D//) and perpendicular diffusivity (D), to localize the regions where occur axonal lesion and demyelization. TBSS was applied to analyze the FA data. After, the regions with alteration were studied with D, D// and D maps. Patients exhibited widespread degradation of FA. With D, D// and D maps analysis we found alterations in corpus callosum, corticospinal tract, fornix, internal capsule, corona radiate, Sagittal stratum, cingulum, fronto-occipital fasciculus and uncinate fasciculus. Our results are consistent with the hypothesis that exist demyelization and axonal damage in patients with TLE.

  3. Toward automated face detection in thermal and polarimetric thermal imagery

    Science.gov (United States)

    Gordon, Christopher; Acosta, Mark; Short, Nathan; Hu, Shuowen; Chan, Alex L.

    2016-05-01

    Visible spectrum face detection algorithms perform pretty reliably under controlled lighting conditions. However, variations in illumination and application of cosmetics can distort the features used by common face detectors, thereby degrade their detection performance. Thermal and polarimetric thermal facial imaging are relatively invariant to illumination and robust to the application of makeup, due to their measurement of emitted radiation instead of reflected light signals. The objective of this work is to evaluate a government off-the-shelf wavelet based naïve-Bayes face detection algorithm and a commercial off-the-shelf Viola-Jones cascade face detection algorithm on face imagery acquired in different spectral bands. New classifiers were trained using the Viola-Jones cascade object detection framework with preprocessed facial imagery. Preprocessing using Difference of Gaussians (DoG) filtering reduces the modality gap between facial signatures across the different spectral bands, thus enabling more correlated histogram of oriented gradients (HOG) features to be extracted from the preprocessed thermal and visible face images. Since the availability of training data is much more limited in the thermal spectrum than in the visible spectrum, it is not feasible to train a robust multi-modal face detector using thermal imagery alone. A large training dataset was constituted with DoG filtered visible and thermal imagery, which was subsequently used to generate a custom trained Viola-Jones detector. A 40% increase in face detection rate was achieved on a testing dataset, as compared to the performance of a pre-trained/baseline face detector. Insights gained in this research are valuable in the development of more robust multi-modal face detectors.

  4. Validation of thermal models for a prototypical MEMS thermal actuator.

    Energy Technology Data Exchange (ETDEWEB)

    Gallis, Michail A.; Torczynski, John Robert; Piekos, Edward Stanley; Serrano, Justin Raymond; Gorby, Allen D.; Phinney, Leslie Mary

    2008-09-01

    This report documents technical work performed to complete the ASC Level 2 Milestone 2841: validation of thermal models for a prototypical MEMS thermal actuator. This effort requires completion of the following task: the comparison between calculated and measured temperature profiles of a heated stationary microbeam in air. Such heated microbeams are prototypical structures in virtually all electrically driven microscale thermal actuators. This task is divided into four major subtasks. (1) Perform validation experiments on prototypical heated stationary microbeams in which material properties such as thermal conductivity and electrical resistivity are measured if not known and temperature profiles along the beams are measured as a function of electrical power and gas pressure. (2) Develop a noncontinuum gas-phase heat-transfer model for typical MEMS situations including effects such as temperature discontinuities at gas-solid interfaces across which heat is flowing, and incorporate this model into the ASC FEM heat-conduction code Calore to enable it to simulate these effects with good accuracy. (3) Develop a noncontinuum solid-phase heat transfer model for typical MEMS situations including an effective thermal conductivity that depends on device geometry and grain size, and incorporate this model into the FEM heat-conduction code Calore to enable it to simulate these effects with good accuracy. (4) Perform combined gas-solid heat-transfer simulations using Calore with these models for the experimentally investigated devices, and compare simulation and experimental temperature profiles to assess model accuracy. These subtasks have been completed successfully, thereby completing the milestone task. Model and experimental temperature profiles are found to be in reasonable agreement for all cases examined. Modest systematic differences appear to be related to uncertainties in the geometric dimensions of the test structures and in the thermal conductivity of the

  5. Thermal Decomposition of IMX-104: Ingredient Interactions Govern Thermal Insensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Maharrey, Sean [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wiese-Smith, Deneille [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Highley, Aaron M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Steill, Jeffrey D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Behrens, Richard [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kay, Jeffrey J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-04-01

    This report summarizes initial studies into the chemical basis of the thermal insensitivity of INMX-104. The work follows upon similar efforts investigating this behavior for another DNAN-based insensitive explosive, IMX-101. The experiments described demonstrate a clear similarity between the ingredient interactions that were shown to lead to the thermal insensitivity observed in IMX-101 and those that are active in IMX-104 at elevated temperatures. Specifically, the onset of decomposition of RDX is shifted to a lower temperature based on the interaction of the RDX with liquid DNAN. This early onset of decomposition dissipates some stored energy that is then unavailable for a delayed, more violent release.

  6. Transport of thermal water from well to thermal baths

    Science.gov (United States)

    Montegrossi, Giordano; Vaselli, Orlando; Tassi, Franco; Nocentini, Matteo; Liccioli, Caterina; Nisi, Barbara

    2013-04-01

    The main problem in building a thermal bath is having a hot spring or a thermal well located in an appropriate position for customer access; since Roman age, thermal baths were distributed in the whole empire and often road and cities were built all around afterwards. Nowadays, the perspectives are changed and occasionally the thermal resource is required to be transported with a pipeline system from the main source to the spa. Nevertheless, the geothermal fluid may show problems of corrosion and scaling during transport. In the Ambra valley, central Italy, a geothermal well has recently been drilled and it discharges a Ca(Mg)-SO4, CO2-rich water at the temperature of 41 °C, that could be used for supplying a new spa in the surrounding areas of the well itself. The main problem is that the producing well is located in a forest tree ca. 4 km far away from the nearest structure suitable to host the thermal bath. In this study, we illustrate the pipeline design from the producing well to the spa, constraining the physical and geochemical parameters to reduce scaling and corrosion phenomena. The starting point is the thermal well that has a flow rate ranging from 22 up to 25 L/sec. The thermal fluid is heavily precipitating calcite (50-100 ton/month) due to the calcite-CO2 equilibrium in the reservoir, where a partial pressure of 11 bar of CO2 is present. One of the most vexing problems in investigating scaling processed during the fluid transport in the pipeline is that there is not a proper software package for multiphase fluid flow in pipes characterized by such a complex chemistry. As a consequence, we used a modified TOUGHREACT with Pitzer database, arranged to use Darcy-Weisbach equation, and applying "fictitious" material properties in order to give the proper y- z- velocity profile in comparison to the analytical solution for laminar fluid flow in pipes. This investigation gave as a result the lowest CO2 partial pressure to be kept in the pipeline (nearly 2

  7. Deficits in pain perception in borderline personality disorder: results from the thermal grill illusion.

    Science.gov (United States)

    Bekrater-Bodmann, Robin; Chung, Boo Young; Richter, Ingmarie; Wicking, Manon; Foell, Jens; Mancke, Falk; Schmahl, Christian; Flor, Herta

    2015-10-01

    It is well documented that borderline personality disorder (BPD) is characterized by reduced pain sensitivity, which might be related to nonsuicidal self-injury and dissociative experiences in patients with BPD. However, it remains an open question whether this insensitivity relies at least partly on altered sensory integration or on an altered evaluation of pain or a combination of both. In this study, we used the thermal grill illusion (TGI), describing a painful sensation induced by the application of alternating cold and warm nonnoxious stimuli, in patients with either current or remitted BPD as well as matched healthy controls. Two additional conditions, applying warm or cold temperatures only, served as control. We further assessed thermal perception, discrimination, and pain thresholds. We found significantly reduced heat and cold pain thresholds for the current BPD group, as well as reduced cold pain thresholds for the remitted BPD group, as compared with the HC group. Current BPD patients perceived a less-intense TGI in terms of induced pain and unpleasantness, while their general ability to perceive this kind of illusion seemed to be unaffected. Thermal grill illusion magnitude was negatively correlated with dissociation and traumatization only in the current BPD patients. These results indicate that higher-order pain perception is altered in current BPD, which seems to normalize after remission. We discuss these findings against the background of neurophysiological evidence for the TGI in general and reduced pain sensitivity in BPD and suggest a relationship to alterations in N-methyl-D-aspartate neurotransmission.

  8. Thermal conductivity of graphene laminate.

    Science.gov (United States)

    Malekpour, H; Chang, K-H; Chen, J-C; Lu, C-Y; Nika, D L; Novoselov, K S; Balandin, A A

    2014-09-10

    We have investigated thermal conductivity of graphene laminate films deposited on polyethylene terephthalate substrates. Two types of graphene laminate were studied, as deposited and compressed, in order to determine the physical parameters affecting the heat conduction the most. The measurements were performed using the optothermal Raman technique and a set of suspended samples with the graphene laminate thickness from 9 to 44 μm. The thermal conductivity of graphene laminate was found to be in the range from 40 to 90 W/mK at room temperature. It was found unexpectedly that the average size and the alignment of graphene flakes are more important parameters defining the heat conduction than the mass density of the graphene laminate. The thermal conductivity scales up linearly with the average graphene flake size in both uncompressed and compressed laminates. The compressed laminates have higher thermal conductivity for the same average flake size owing to better flake alignment. Coating plastic materials with thin graphene laminate films that have up to 600× higher thermal conductivity than plastics may have important practical implications.

  9. Thermal animal detection system (TADS)

    Energy Technology Data Exchange (ETDEWEB)

    Desholm, M.

    2003-03-01

    This report presents data from equipment tests and software development for the Thermal Animal Detection System (TADS) development project: 'Development of a method for estimating collision frequency between migrating birds and offshore wind turbines'. The technical tests were performed to investigate the performance of remote controlling, video file compression tool and physical stress of the thermal camera when operating outdoors and under the real time vibration conditions at a 2 MW turbine. Furthermore, experimental tests on birds were performed to describe the decreasing detectability with distance on free flying birds, the performance of the thermal camera during poor visibility, and finally, the performance of the thermal sensor software developed for securing high -quality data. In general, it can be concluded that the thermal camera and its related hardware and software, the TADS, are capable of recording migrating birds approaching the rotating blades of a turbine, even under conditions with poor visibility. If the TADS is used in a vertical viewing scenario it would comply with the requirements for a setup used for estimating the avian collision frequency at offshore wind turbines. (au)

  10. Thermal Insulation from Hardwood Residues

    Science.gov (United States)

    Sable, I.; Grinfelds, U.; Vikele, L.; Rozenberga, L.; Zeps, M.; Luguza, S.

    2015-11-01

    Adequate heat is one of the prerequisites for human wellbeing; therefore, building insulation is required in places where the outside temperature is not suitable for living. The climate change, with its rising temperatures and longer dry periods, promotes enlargement of the regions with conditions more convenient for hardwood species than for softwood species. Birch (Betula pendula) is the most common hardwood species in Latvia. The aim of this work was to obtain birch fibres from wood residues of plywood production and to form low-density thermal insulation boards. Board formation and production was done in the presence of water; natural binder, fire retardant and fungicide were added in different concentrations. Board properties such as density, transportability or resistance to particulate loss, thermal conductivity and reaction to fire were investigated. This study included thermal insulation boards with the density of 102-120 kg/m3; a strong correlation between density and the binder amount was found. Transportability also improved with the addition of a binder, and 0.1-0.5% of the binder was the most appropriate amount for this purpose. The measured thermal conductivity was in the range of 0.040-0.043 W/(m·K). Fire resistance increased with adding the fire retardant. We concluded that birch fibres are applicable for thermal insulation board production, and it is possible to diversify board properties, changing the amount of different additives.

  11. Physiological activity in calm thermal indoor environments.

    Science.gov (United States)

    Okamoto, Tsuyoshi; Tamura, Kaori; Miyamoto, Naoyuki; Tanaka, Shogo; Futaeda, Takaharu

    2017-09-14

    Indoor environmental comfort has previously been quantified based on the subjective assessment of thermal physical parameters, such as temperature, humidity, and airflow velocity. However, the relationship of these parameters to brain activity remains poorly understood. The objective of this study was to determine the effect of airflow on brain activity using electroencephalograms (EEG) of participants in a living environment under different airflow conditions. Before the recording, the room was set to a standardised air temperature and humidity. During the recording, each participant was required to perform a simple time-perception task that involved pressing buttons after estimating a 10-second interval. Cooling and heating experiments were conducted in summer and winter, respectively. A frequency analysis of the EEGs revealed that gamma and beta activities showed lower amplitudes under conditions without airflow than with airflow, regardless of the season (i.e., cooling or heating). Our results reveal new neurophysiological markers of the response to airflow sensation. Further, based on the literature linking gamma and beta waves to less anxious states in calm environments, we suggest that airflow may alter the feelings of the participants.

  12. Thermal aging of nitroplasticized Estane 5703

    Energy Technology Data Exchange (ETDEWEB)

    Orler, E. B. (E. Bruce); Wrobleski, Debra A.; Cooke, D. W. (D. Wayne); Bennett, B. L. (Bryan L.); Smith, M. E. (Mark E.); Jahan, M. S. (M. Shan)

    2002-01-01

    In support of the Lifetime Prediction modeling effort, we have been investigating the aging processes that could impact the lifetime of PBX 9501. PBX 9501 is composed of 95% HMX and 5% polymeric binder. The polymeric binder is composed of 50% nitroplasticizer (NP) and 50% Estane{reg_sign} 5703 with a small quantity of stabilizer. Estane{reg_sign} 5703 is a segmented poly(ester urethane) with mechanical properties derived from phase separation of hard and soft segments along the polymer backbone. Since the binder has a significant effect on the composite mechanical properties, it is essential to know how the binder changes with time. Typically, polymer lifetime predictions are determined from extrapolation of properties after the material has been exposed to elevated temperatures and/or reactive environments for varying periods of time. For multiphase polymers, this accelerated aging methodology is very difficult to interpret since elevated temperatures alter the physical structure of the polymer, as well as, accelerate the chemical degradation reactions. Accelerated aging studies of nitroplasticized Estane have shown an increase in the molecular weight. The increase in molecular weight is most likely due to polymer chain branching reactions that eventually leads to formation an insoluble cross-linked gel. The decreased chain mobility caused by branching may also affect phase separation, which in turn, may change the mechanical properties. In this paper we report results of thermal aging studies on the properties, morphology and chemistry of nitroplasticized Estane.

  13. The electronic thermal conductivity of graphene

    OpenAIRE

    Kim, Tae Yun; Park, Cheol-Hwan; Marzari, Nicola

    2016-01-01

    Graphene, as a semimetal with the largest known thermal conductivity, is an ideal system to study the interplay between electronic and lattice contributions to thermal transport. While the total electrical and thermal conductivity have been extensively investigated, a detailed first-principles study of its electronic thermal conductivity is still missing. Here, we first characterize the electron-phonon intrinsic contribution to the electronic thermal resistivity of graphene as a function of d...

  14. Low-thermal expansion infrared glass ceramics

    Science.gov (United States)

    Lam, Philip

    2009-05-01

    L2 Tech, Inc. is in development of an innovative infrared-transparent glass ceramic material with low-thermal expansion (ZrW2O8) which has Negative Thermal Expansion (NTE). The glass phase is the infrared-transparent germanate glass which has positive thermal expansion (PTE). Then glass ceramic material has a balanced thermal expansion of near zero. The crystal structure is cubic and the thermal expansion of the glass ceramic is isotropic or equal in all directions.

  15. Low Thermal Expansion Glass Ceramics

    CERN Document Server

    Bach, Hans

    2005-01-01

    This book appears in the authoritative series reporting the international research and development activities conducted by the Schott group of companies. This series provides an overview of Schott's activities for scientists, engineers, and managers from all branches of industry worldwide in which glasses and glass ceramics are of interest. Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated. This new extended edition describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics. The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions. Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization. Thus g...

  16. Thermalizing Sterile Neutrino Dark Matter

    Science.gov (United States)

    Hansen, Rasmus S. L.; Vogl, Stefan

    2017-12-01

    Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of keV sterile neutrino dark matter in the early Universe. Based on general considerations we find a mechanism which thermalizes the sterile neutrinos after an initial production by oscillations. The thermalization of sterile neutrinos is accompanied by dark entropy production which increases the yield of dark matter and leads to a lower characteristic momentum. This resolves the growing tensions with structure formation and x-ray observations and even revives simple nonresonant production as a viable way to produce sterile neutrino dark matter. We investigate the parameters required for the realization of the thermalization mechanism in a representative model and find that a simple estimate based on energy and entropy conservation describes the mechanism well.

  17. Thermalizing Sterile Neutrino Dark Matter.

    Science.gov (United States)

    Hansen, Rasmus S L; Vogl, Stefan

    2017-12-22

    Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of keV sterile neutrino dark matter in the early Universe. Based on general considerations we find a mechanism which thermalizes the sterile neutrinos after an initial production by oscillations. The thermalization of sterile neutrinos is accompanied by dark entropy production which increases the yield of dark matter and leads to a lower characteristic momentum. This resolves the growing tensions with structure formation and x-ray observations and even revives simple nonresonant production as a viable way to produce sterile neutrino dark matter. We investigate the parameters required for the realization of the thermalization mechanism in a representative model and find that a simple estimate based on energy and entropy conservation describes the mechanism well.

  18. Thermal Emission from Structured Media

    Science.gov (United States)

    Zimmerman, Ian Andrew

    This dissertation covers a study of the use of macroscopic structure as a means of controlling thermal emission in the THz and mid-IR frequency regions. Chapter 1 presents a brief introduction to the THz frequency region and to the concept of the photonic crystal, the primary type of geometry used. Chapter 2 compares the two most common methods used to calculate the thermal emission of a structure whose components are all at the same temperature. These methods are compared in terms of the results they give and in terms of how computationally involved the methods are. The first method explored involves using Kirchhoff's law of thermal emission which equates the absorptivity and emissivity of a structure. The second method is to calculate the emission directly from the Green's function using the microscopic thermal currents given by the Fluctuation-Dissipation theorem. A derivation of the second method is given, and the equality between the two methods is proven in 1D. It is shown that the Kirchhoff's law method is much more computationally efficient, and it is therefore used for the parametric studies of the structures which make up the remainder of this document. Chapter 3 covers work done in the THz regime. In the THz frequency regime, where a historic lack of sources has in part impeded full exploration and utilization, a photonic crystal design is proposed to control the thermal emission. It is shown that using a 1D bi-layered photonic crystal, composed of alternating section of silicon wafers and vacuum sections, it is possible to tailor many narrowband emission features over a broadband frequency range. In simulation both spectral and directional thermal emission control is demonstrated, and a parametric study is performed to explore how changes in the geometry of the photonic crystal change its thermal emission signature. A description is then given of how the photonic crystal is constructed and how its thermal emission is measured using Fourier transform

  19. Altered States: Globalization, Sovereignty, and Governance | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    In Altered States, Gordon Smith and Moisés Naím provide practical recommendations for improved governance and for strengthening and reforming the United Nations. They explore the dynamics of globalization and discuss what makes today's globalization distinct. They test the prevailing wisdom about sovereignty and ...

  20. The Correlation between Physiological and Structural Alterations ...

    African Journals Online (AJOL)

    2004) and ultrastructural. (Papadakis et al. 2004) alterations in the vegetative organs of plants. Heavy-metal-induced decreases in cell wall elasticity have also been recorded (Barceló et al. 1989). The physiological effects of heavy metals on plants include: (i) perturbation of stomatal functions leading to changes in water ...

  1. Diabetic rat testes: morphological and functional alterations.

    Science.gov (United States)

    Ricci, G; Catizone, A; Esposito, R; Pisanti, F A; Vietri, M T; Galdieri, M

    2009-12-01

    Reproductive dysfunction is a consequence of diabetes, but the underlying mechanisms are poorly understood. This study investigated the histological and molecular alterations in the testes of rats injected with streptozotocin at prepuperal (SPI rats) and adult age (SAI rats) to understand whether diabetes affects testicular tissue with different severity depending on the age in which this pathological condition starts. The testes of diabetic animals showed frequent abnormal histology, and seminiferous epithelium cytoarchitecture appeared altered as well as the occludin distribution pattern. The early occurrence of diabetes increased the percentage of animals with high number of damaged tubules. The interstitial compartment of the testes was clearly hypertrophic in several portions of the organs both in SPI and SAI rats. Interestingly, fully developed Leydig cells were present in all the treated animals although abnormally distributed. Besides the above-described damages, we found a similar decrease in plasma testosterone levels both in SPI and SAI rats. Oxidative stress (OS) is involved in the pathogenesis of various diabetic complications, and in our experimental models we found that manganese superoxide dismutase was reduced in diabetic animals. We conclude that in STZ-induced diabetes, the altered spermatogenesis, more severe in SPI animals, is possibly due to the effect of OS on Leydig cell function which could cause the testosterone decrease responsible for the alterations found in the seminiferous epithelium of diabetic animals.

  2. Lessons from altered states of consciousness

    African Journals Online (AJOL)

    temporal association areas, occipitoparietal association cortices and occipital cortex.3 ... Abstract. Key research related to consciousness is that which investigates the neural systems that are deactivated or attenuated during altered states of ... integration of neural networks with the final common mechanism for anaesthesia ...

  3. Sulphur depletion altered somatic embryogenesis in Theobroma ...

    African Journals Online (AJOL)

    USER

    2010-08-30

    Aug 30, 2010 ... chemical or characteristic functions of these biomolecules in cells (Saito, 2004). In growing conditions, sulphur defi- ciency challenges plants (explants) to alter the metabolism necessary for growth. Restriction in sulphur not only limits the synthesis of sulphurous amino acids, but will also limit the proteins ...

  4. Haematological alterations probably underlining anoestrus in ...

    African Journals Online (AJOL)

    Haematological alterations are consistent with trypanosomosis, which is an important cause of reproductive wastage in many species of food animals.The haematological changes associated with Typanosoma brucei infection in oestrous synchronized goats were investigated using twelve adult West African Dwarf (WAD) ...

  5. Public health implications of altered puberty timing

    DEFF Research Database (Denmark)

    Golub, Mari S; Collman, Gwen W; Foster, Paul M D

    2008-01-01

    sexual debut, potential sexual abuse, and psychosocial difficulties. Altered puberty timing is also of concern for the development of reproductive tract cancers later in life. For example, an early age of menarche is a risk factor for breast cancer. A low age at male puberty is associated...

  6. Can Molecular Hippocampal Alterations Explain Behavioral ...

    Science.gov (United States)

    Studies in both humans and animals have shown that prenatal stress can alter cognitive function and other neurological behaviors in adult offspring. One possible underlying mechanism for this may lie with alterations in hippocampal gene expression. The present study examined genotypical outcomes in adult male and female offspring of rats exposed to variable stress during pregnancy. Dams (n=15/treatment) were subjected to several non-chemical stressors including intermittent noise, light, crowding, restraint, and altered circadian lighting, from gestational day (GD) 13 to 20. Tail blood was drawn on GD 12, 16 and 20 to verify a stress response. Corticosterone levels were not different between the stressed and non-stressed dams on GD12 but was significantly increased in stressed dams on GD 16 and 20 compared to controls. Dams gave birth on GD22 (postnatal day or PND 0). Several behavioral tests were used to assess the cognitive and behavioral phenotype of the offspring from PND 49 through 86, including the Morris water maze and novel object recognition. Male and female stressed offspring showed reduced reversal learning on the Morris water maze and stressed females did not show a significant preference for the novel object (57 ± 8%) while control females did (71 ± 3%). This indicates altered cognition in prenatally stressed offspring. On PND 91-92, offspring were necropsied and hippocampal tissue was collected. Genotypic outcomes of prenatal stress w

  7. Altered membrane permeability in multidrug resistant Escherichia ...

    African Journals Online (AJOL)

    The study was conducted with the objective of examining the outer membrane proteins and their involvement during the transport of β - lactams in multidrug resistant Escherichia coli isolated from extra-intestinal infections. Also, the response of gram negative bacterial biomembrane alteration was studied using extended ...

  8. Connective tissue alteration in abdominal wall hernia

    DEFF Research Database (Denmark)

    Henriksen, N A; Yadete, D H; Sørensen, Lars Tue

    2011-01-01

    The aetiology and pathogenesis of abdominal wall hernia formation is complex. Optimal treatment of hernias depends on a full understanding of the pathophysiological mechanisms involved in their formation. The aim of this study was to review the literature on specific collagen alterations...... in abdominal wall hernia formation....

  9. In Situ Alloying of Thermally Conductive Polymer Composites by Combining Liquid and Solid Metal Microadditives.

    Science.gov (United States)

    Ralphs, Matthew I; Kemme, Nicholas; Vartak, Prathamesh B; Joseph, Emil; Tipnis, Sujal; Turnage, Scott; Solanki, Kiran N; Wang, Robert Y; Rykaczewski, Konrad

    2018-01-17

    Room-temperature liquid metals (LMs) are attractive candidates for thermal interface materials (TIMs) because of their moderately high thermal conductivity and liquid nature, which allow them to conform well to mating surfaces with little thermal resistance. However, gallium-based LMs may be of concern due to the gallium-driven degradation of many metal microelectronic components. We present a three-component composite with LM, copper (Cu) microparticles, and a polymer matrix, as a cheaper, noncorrosive solution. The solid copper particles alloy with the gallium in the LM, in situ and at room temperature, immobilizing the LM and eliminating any corrosion issues of nearby components. Investigation of the structure-property-process relationship of the three-component composites reveals that the method and degree of additive blending dramatically alter the resulting thermal transport properties. In particular, microdispersion of any combination of the LM and Cu additives results in a large number of interfaces and a thermal conductivity below 2 W m -1 K -1 . In contrast, a shorter blending procedure of premixed LM and Cu particle colloid into the polymer matrix yields a composite with polydispersed filler and effective intrinsic thermal conductivities of up to 17 W m -1 K -1 (effective thermal conductivity of up to 10 W m -1 K -1 ). The LM-Cu colloid alloying into CuGa 2 provides a limited, but practical, time frame to cast the uncured composite into the desired shape, space, or void before the composite stiffens and cures with permanent characteristics.

  10. Effect of oral dietary supplement for chicks subjected to thermal oscillation on performance and intestinal morphometry

    Directory of Open Access Journals (Sweden)

    Jovanir Inês Müller Fernandes

    2017-09-01

    Full Text Available The aim of the study was to evaluate the efficacy of a nutritional formulation based on amino acids and vitamins supplemented in the drinking water for chicks in the first week of life subjected to thermal oscillation on performance, organ development and intestinal morphometry from 1 to 21 days. 640-male broiler chicks were distributed in a 2x2 factorial completely randomized design (with or without dietary supplementation and at comfort temperature or thermal oscillation. Chicks subjected to thermal oscillation presented worse performance (p < 0.05 than those under thermal comfort of 1 to 7, 1 to 14 and 1 to 21 days. Nutritional supplementation did not alter the performance (p < 0.05 of the birds, but resulted in a higher body weight (p < 0.05 regardless of the environmental thermal condition. At 7 days, chicks under thermal comfort had better intestinal morphometric parameters (p < 0.05, in relation to birds under thermal oscillation. In conclusion, the temperature oscillations caused negative consequences to the productive performance and the intestinal morphology of chicks for which dietary supplementation was not enough to mitigate the effects of the environmental challenge during the first week of life of the birds.

  11. [Using infrared thermal asymmetry analysis for objective assessment of the lesion of facial nerve function].

    Science.gov (United States)

    Liu, Xu-long; Hong, Wen-xue; Song, Jia-lin; Wu, Zhen-ying

    2012-03-01

    The skin temperature distribution of a healthy human body exhibits a contralateral symmetry. Some lesions of facial nerve function are associated with an alteration of the thermal distribution of the human body. Since the dissipation of heat through the skin occurs for the most part in the form of infrared radiation, infrared thermography is the method of choice to capture the alteration of the infrared thermal distribution. This paper presents a new method of analysis of the thermal asymmetry named effective thermal area ratio, which is a product of two variables. The first variable is mean temperature difference between the specific facial region and its contralateral region. The second variable is a ratio, which is equal to the area of the abnormal region divided by the total area. Using this new method, we performed a controlled trial to assess the facial nerve function of the healthy subjects and the patients with Bell's palsy respectively. The results show: that the mean specificity and sensitivity of this method are 0.90 and 0.87 respectively, improved by 7% and 26% compared with conventional methods. Spearman correlation coefficient between effective thermal area ratio and the degree of facial nerve function is an average of 0.664. Hence, concerning the diagnosis and assessment of facial nerve function, infrared thermography is a powerful tool; while the effective ther mal area ratio is an efficient clinical indicator.

  12. Thermal hydrodynamic analysis of a countercurrent gas centrifuge; Analise termo hidrodinamica de uma centrifuga a contracorrente

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Delvonei Alves de

    1999-07-01

    The influence of the thermal countercurrent on the separative performance of countercurrent centrifuges is treated in this work. The methodology used consists in modeling the gas flow inside the rotor under thermal boundary conditions supplied by the structural thermal model. The gas flow model, also called hydrodynamical model, is based on the Finite Volume Method for cylindrical geometry with azimuthal symmetry. The structural thermal model is based on the Nodal Method and take into account simultaneously, the conduction convection and radiation phenomena. The procedure adopted for this study consisted in the definition of the operational and geometric conditions of a centrifuge which was used as a pattern to the accomplished analysis. This configuration, called 'Standard Centrifuge', was used for the accomplishment of several simulations where the importance of the realistic boundary thermal conditions for the numerical evaluation of the centrifuge separative capacity was evidenced. A selective alteration for the optical properties based on simple engineering procedures was proposed. An improvement of 5% was obtained with this alteration. (author)

  13. Experimental Characterization of a Composite Morphing Radiator Prototype in a Relevant Thermal Environment

    Science.gov (United States)

    Bertagne, Christopher L.; Chong, Jorge B.; Whitcomb, John D.; Hartl, Darren J.; Erickson, Lisa R.

    2017-01-01

    For future long duration space missions, crewed vehicles will require advanced thermal control systems to maintain a desired internal environment temperature in spite of a large range of internal and external heat loads. Current radiators are only able to achieve turndown ratios (i.e. the ratio between the radiator's maximum and minimum heat rejection rates) of approximately 3:1. Upcoming missions will require radiators capable of 12:1 turndown ratios. A radiator with the ability to alter shape could significantly increase turndown capacity. Shape memory alloys (SMAs) offer promising qualities for this endeavor, namely their temperature-dependent phase change and capacity for work. In 2015, the first ever morphing radiator prototype was constructed in which SMA actuators passively altered the radiator shape in response to a thermal load. This work describes a follow-on endeavor to demonstrate a similar concept using highly thermally conductive composite materials. Numerous versions of this new concept were tested in a thermal vacuum environment and successfully demonstrated morphing behavior and variable heat rejection, achieving a turndown ratio of 4.84:1. A summary of these thermal experiments and their results are provided herein.

  14. Thermal effects in microfluidics with thermal conductivity spatially modulated

    Science.gov (United States)

    Vargas Toro, Agustín.

    2014-05-01

    A heat transfer model on a microfluidic is resolved analytically. The model describes a fluid at rest between two parallel plates where each plate is maintained at a differentially specified temperature and the thermal conductivity of the microfluidic is spatially modulated. The heat transfer model in such micro-hydrostatic configuration is analytically resolved using the technique of the Laplace transform applying the Bromwich Integral and the Residue theorem. The temperature outline in the microfluidic is presented as an infinite series of Bessel functions. It is shown that the result for the thermal conductivity spatially modulated has as a particular case the solution when the thermal conductivity is spatially constant. All computations were performed using the computer algebra software Maple. It is claimed that the analytical obtained results are important for the design of nanoscale devices with applications in biotechnology. Furthermore, it is suggested some future research lines such as the study of the heat transfer model in a microfluidic resting between coaxial cylinders with radially modulated thermal conductivity in order to achieve future developments in this area.

  15. Altered gut microbiota in Rett syndrome.

    Science.gov (United States)

    Strati, Francesco; Cavalieri, Duccio; Albanese, Davide; De Felice, Claudio; Donati, Claudio; Hayek, Joussef; Jousson, Olivier; Leoncini, Silvia; Pindo, Massimo; Renzi, Daniela; Rizzetto, Lisa; Stefanini, Irene; Calabrò, Antonio; De Filippo, Carlotta

    2016-07-30

    The human gut microbiota directly affects human health, and its alteration can lead to gastrointestinal abnormalities and inflammation. Rett syndrome (RTT), a progressive neurological disorder mainly caused by mutations in MeCP2 gene, is commonly associated with gastrointestinal dysfunctions and constipation, suggesting a link between RTT's gastrointestinal abnormalities and the gut microbiota. The aim of this study was to evaluate the bacterial and fungal gut microbiota in a cohort of RTT subjects integrating clinical, metabolomics and metagenomics data to understand if changes in the gut microbiota of RTT subjects could be associated with gastrointestinal abnormalities and inflammatory status. Our findings revealed the occurrence of an intestinal sub-inflammatory status in RTT subjects as measured by the elevated values of faecal calprotectin and erythrocyte sedimentation rate. We showed that, overall, RTT subjects harbour bacterial and fungal microbiota altered in terms of relative abundances from those of healthy controls, with a reduced microbial richness and dominated by microbial taxa belonging to Bifidobacterium, several Clostridia (among which Anaerostipes, Clostridium XIVa, Clostridium XIVb) as well as Erysipelotrichaceae, Actinomyces, Lactobacillus, Enterococcus, Eggerthella, Escherichia/Shigella and the fungal genus Candida. We further observed that alterations of the gut microbiota do not depend on the constipation status of RTT subjects and that this dysbiotic microbiota produced altered short chain fatty acids profiles. We demonstrated for the first time that RTT is associated with a dysbiosis of both the bacterial and fungal component of the gut microbiota, suggesting that impairments of MeCP2 functioning favour the establishment of a microbial community adapted to the costive gastrointestinal niche of RTT subjects. The altered production of short chain fatty acids associated with this microbiota might reinforce the constipation status of RTT

  16. Alteration and long-term behaviour of different types of innovative materials for long-lived radionuclides confinement; Alteration et comportement a long terme de differentes classes de materiaux innovants pour le confinement des radionucleides a vie longue

    Energy Technology Data Exchange (ETDEWEB)

    Leturcq, G

    1998-09-29

    The present work is an experimental study on alteration mechanisms of synthetic and natural materials: aluminosilicate glasses, glass ceramics and Ti, Zr or P based ceramics. It is a part of CEA's study program on the immobilization of long- lived radionuclides and deals with chemical processes which control dissolution of amorphous and crystallized solids. The different aluminosilicate glasses studied are altered according to a process of hydrolysis of the bonds between the glass network formers; the activation energy of this reaction is about 60 kJ/mol. Alteration rates of all the glasses decrease by four orders of magnitude when the reaction progress increases. Kinetic laws based on the deviation from the thermodynamic equilibrium between leachate and the fresh solid cannot explain these great decreases. Alteration layers in the reactional interface seem to control the alteration kinetics by providing a passivation process. The chemical durability of the glass ceramics (zirconolite and titanite) improves by a factor of ten in regard to the primary glasses which were obtained by thermal treatment. Zirconium-titanate ceramics are altered only slightly by water. The altered mass corresponds to a few atomic layers only. Steady stases are quickly observed. On the basis of thermodynamic calculations, they are not correlated with saturation between the leachate and primary zirconium-titanate phases. Alteration here also ceases due to the development of a passivating layer. Models aiming at studying the chemical durability of zirconium-titanate ceramics under conditions more representative of a clayey site of geological storage were carried out. The results of the interactions of these ceramics with clays, at 708 deg.C, show clearly that there is no modification of the process of alteration, compared to the simpler pure water systems. Thus, perovskite and zirconolite do not deteriorate under these conditions. (author)

  17. What can Recycling in Thermal Reactors Accomplish?

    Energy Technology Data Exchange (ETDEWEB)

    Steven Piet; Gretchen E. Matthern; Jacob J. Jacobson

    2007-09-01

    Thermal recycle provides several potential benefits when used as stop-gap, mixed, or backup recycling to recycling in fast reactors. These three roles involve a mixture of thermal and fast recycling; fast reactors are required to some degree at some time. Stop-gap uses thermal reactors only until fast reactors are adequately deployed and until any thermal-recycle-only facilities have met their economic lifetime. Mixed uses thermal and fast reactors symbiotically for an extended period of time. Backup uses thermal reactors only if problems later develop in the fast reactor portion of a recycling system. Thermal recycle can also provide benefits when used as pure thermal recycling, with no intention to use fast reactors. However, long term, the pure thermal recycling approach is inadequate to meet several objectives.

  18. 28 CFR 36.403 - Alterations: Path of travel.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Alterations: Path of travel. 36.403... Alterations: Path of travel. (a) General. An alteration that affects or could affect the usability of or... the maximum extent feasible, the path of travel to the altered area and the restrooms, telephones, and...

  19. Hydrothermal Alteration on Basaltic Mauna Kea Volcano as a Template for Identification of Hydrothermal Alteration on Basaltic Mars

    Science.gov (United States)

    Morris, R. V.; Graff, T. G.; Ming, D. W.; Mertzman, S. A.; Bell, J. F., III

    2003-01-01

    Certain samples of palagonitic tephra from Mauna Kea Volcano (Hawaii) are spectral analogues for bright martian surface materials at visible and near-IR wavelengths because both are characterized by a ferric absorption edge extending from about 400 to 750 nm and relatively constant reflectivity extending from about 750 nm to beyond 2000 nm. Palagonite is a yellow or orange isotropic mineraloid formed by hydration and devitrification of basaltic glass. For Mars-analogue palagonite, the pigment is nanometersized ferric oxide particles (np-Ox) dispersed throughout an allophane-like hydrated basaltic glass matrix. Crystalline phyllosilicates are not generally detected, and the hydration state of the is not known. The poorly crystalline nature of glass alteration products implies relatively low temperature formation pathways. We report here x-ray diffraction, major element, Mossbauer, and VNIR data for 9 basaltic tephras. Thermal emission spectra are reported in a separate abstract. Our multidisciplinary approach both tightly constrains mineralogical interpretations and maximizes overlap with datasets available for the martian surface available now and in the future.

  20. Thermally induced osteocyte damage initiates a remodelling signaling cascade.

    Directory of Open Access Journals (Sweden)

    Eimear B Dolan

    Full Text Available Thermal elevations experienced by bone during orthopaedic procedures, such as cutting and drilling, exothermal reactions from bone cement, and thermal therapies such as tumor ablation, can result in thermal damage leading to death of native bone cells (osteocytes, osteoblasts, osteoclasts and mesenchymal stem cells. Osteocytes are believed to be the orchestrators of bone remodeling, which recruit nearby osteoclast and osteoblasts to control resorption and bone growth in response to mechanical stimuli and physical damage. However, whether heat-induced osteocyte damage can directly elicit bone remodelling has yet to be determined. This study establishes the link between osteocyte thermal damage and the remodeling cascade. We show that osteocytes directly exposed to thermal elevations (47°C for 1 minute become significantly apoptotic and alter the expression of osteogenic genes (Opg and Cox2. The Rankl/Opg ratio is consistently down-regulated, at days 1, 3 and 7 in MLO-Y4s heat-treated to 47°C for 1 minute. Additionally, the pro-osteoblastogenic signaling marker Cox2 is significantly up-regulated in heat-treated MLO-Y4s by day 7. Furthermore, secreted factors from heat-treated MLO-Y4s administered to MSCs using a novel co-culture system are shown to activate pre-osteoblastic MSCs to increase production of the pro-osteoblastic differentiation marker, alkaline phosphatase (day 7, 14, and calcium deposition (day 21. Most interestingly, an initial pro-osteoclastogenic signaling response (increase Rankl and Rankl/Opg ratio at day 1 followed by later stage pro-osteoblastogenic signaling (down-regulation in Rankl and the Rankl/Opg ratio and an up-regulation in Opg and Cox2 by day 7 was observed in non-heat-treated MLO-Y4s in co-culture when these were exposed to the biochemicals produced by heat-treated MLO-Y4s. Taken together, these results elucidate the vital role of osteocytes in detecting and responding to thermal damage by means of thermally

  1. Thermal energy storage devices, systems, and thermal energy storage device monitoring methods

    Science.gov (United States)

    Tugurlan, Maria; Tuffner, Francis K; Chassin, David P.

    2016-09-13

    Thermal energy storage devices, systems, and thermal energy storage device monitoring methods are described. According to one aspect, a thermal energy storage device includes a reservoir configured to hold a thermal energy storage medium, a temperature control system configured to adjust a temperature of the thermal energy storage medium, and a state observation system configured to provide information regarding an energy state of the thermal energy storage device at a plurality of different moments in time.

  2. 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.

  3. 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.

  4. Multipurpose Thermal Insulation Test Apparatus

    Science.gov (United States)

    Fesmire, James E. (Inventor); Augustynowicz, Stanislaw D. (Inventor)

    2002-01-01

    A multi-purpose thermal insulation test apparatus is used for testing insulation materials, or other components. The test apparatus is a fluid boil-off calorimeter system for calibrated measurement of the apparent thermal conductivity (k-value) of a specimen material at a fixed vacuum level. The apparatus includes an inner vessel for receiving a fluid with a normal boiling point below ambient temperature, such as liquid nitrogen, enclosed within a vacuum chamber. A cold mass assembly, including the inner vessel and thermal guards, is suspended from the top of the vacuum chamber. Handling tools attach to the cold mass assembly for convenient manipulation of the assembly and for the installation or wrapping of insulation test materials. Liquid nitrogen is typically supplied to the inner vessel using a fill tube with funnel. A single port through the top of the vacuum chamber facilitates both filling and venting. Aerogel composite stacks with reflective films are fastened to the top and the bottom of the inner vessel as thermal guards. The comparative k-value of the insulation material is determined by measuring the boil-off flow rate of gas, the temperature differential across the insulation thickness, and the dimensions (length and diameters) of the test specimen.

  5. Thermal insulation properties of walls

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2014-05-01

    Full Text Available Heat-protective qualities of building structures are determined by the qualities of the used materials, adequate design solutions and construction and installation work of high quality. This rule refers both to the structures made of materials similar in their structure and nature and mixed, combined by a construction system. The necessity to ecaluate thermal conductivity is important for a product and for a construction. Methods for evaluating the thermal protection of walls are based on the methods of calculation, on full-scale tests in a laboratory or on objects. At the same time there is a reason to believe that even deep and detailed calculation may cause deviation of the values from real data. Using finite difference method can improve accuracy of the results, but it doesn’t solve all problems. The article discusses new approaches to evaluating thermal insulation properties of walls. The authors propose technique of accurate measurement of thermal insulation properties in single blocks and fragments of walls and structures.

  6. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    The design of a displacement ventilation system involves determination of the flow rate in the thermal plumes. The flow rate in the plumes and the vertical temperature gradient influence each other, and they are influenced by many factors. This paper shows some descriptions of these effects....

  7. Adaptation of thermal power plants

    NARCIS (Netherlands)

    Bogmans, Christian W.J.; Dijkema, Gerard P.J.; Vliet, van Michelle T.H.

    2017-01-01

    When does climate change information lead to adaptation? We analyze thermal power plant adaptation by means of investing in water-saving (cooling) technology to prevent a decrease in plant efficiency and load reduction. A comprehensive power plant investment model, forced with downscaled climate

  8. Thermally stimulated luminescence and photoluminescence ...

    Indian Academy of Sciences (India)

    Thermally stimulated luminescence (TSL) investigations of SrBPO5:Eu3+ and SrBPO5:Eu2+ phosphors were carried out in the temperature range of 300–650 K. In order to characterize the phosphors, X-ray diffraction and photoluminescence (PL) techniques were used. The emission spectrum of air heated SrBPO5:Eu3+ ...

  9. Tactile perception of thermal diffusivity

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.|info:eu-repo/dai/nl/262668424; Kappers, A.M.L.|info:eu-repo/dai/nl/07445370X

    2009-01-01

    The thermal diffusivity of an object is a parameter that controls the rate at which heat is extracted from the hand when it touches that object. It is an important feature for distinguishing materials by means of touch. In order to quantitatively describe the ability of human observers to

  10. Maxwell's Contributions to Thermal Physics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 5. Maxwell's Contributions to Thermal Physics. Sisir Bhanja. General Article Volume 8 Issue 5 May 2003 pp 57-72. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/05/0057-0072. Keywords.

  11. Thermal decomposition of ammonium hexachloroosmate

    DEFF Research Database (Denmark)

    Asanova, T I; Kantor, Innokenty; Asanov, I. P.

    2016-01-01

    polymeric structure. Being revealed for the first time the intermediate was subjected to determine the local atomic structure around osmium. The thermal decomposition of hexachloroosmate is much more complex and occurs within a minimum two-step process, which has never been observed before....

  12. Understanding Thermal Equilibrium through Activities

    Science.gov (United States)

    Pathare, Shirish; Huli, Saurabhee; Nachane, Madhura; Ladage, Savita; Pradhan, Hemachandra

    2015-01-01

    Thermal equilibrium is a basic concept in thermodynamics. In India, this concept is generally introduced at the first year of undergraduate education in physics and chemistry. In our earlier studies (Pathare and Pradhan 2011 "Proc. episteme-4 Int. Conf. to Review Research on Science Technology and Mathematics Education" pp 169-72) we…

  13. Rapid thermal processing of semiconductors

    CERN Document Server

    Borisenko, Victor E

    1997-01-01

    Rapid thermal processing has contributed to the development of single wafer cluster processing tools and other innovations in integrated circuit manufacturing environments Borisenko and Hesketh review theoretical and experimental progress in the field, discussing a wide range of materials, processes, and conditions They thoroughly cover the work of international investigators in the field

  14. Furnace for rapid thermal processing

    NARCIS (Netherlands)

    Roozeboom, F.; Duine, P.A.; Sluis, P. van der

    2001-01-01

    A Method (1) for Rapid Thermal Processing of a wafer (7), wherein the wafer (7) is heated by lamps (9), and the heat radiation is reflected by an optical switching device (15,17) which is in the reflecting state during the heating stage. During the cooling stage of the wafer (7), the heat is

  15. Thermal Tracking of Sports Players

    DEFF Research Database (Denmark)

    Gade, Rikke; Moeslund, Thomas B.

    2014-01-01

    We present here a real-time tracking algorithm for thermal video from a sports game. Robust detection of people includes routines for handling occlusions and noise before tracking each detected person with a Kalman filter. This online tracking algorithm is compared with a state-of-the-art offline...

  16. (6) Oriola thermal paper IJAAR

    African Journals Online (AJOL)

    Adeyinka Odunsi

    frying, freezing, drying etc. most of which are often carried out without taking into consideration the actual quantity of heat needed to accomplish a given heat treatment operation. This is as a result of non- availability or inadequacy of information on thermal properties of most local agricultural products (Bart-Plange et al., ...

  17. Photoluminescence, thermally stimulated luminescence and ...

    Indian Academy of Sciences (India)

    Photoluminescence, thermally stimulated luminescence and electron paramagnetic resonance studies of U. 6+ doped BaSO4. M K BHIDE, T K SESHAGIRI. ∗. , SASHIKALA OJHA† and S V GODBOLE. Radiochemistry Division, †Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.

  18. Temperature distribution and thermal stress

    Indian Academy of Sciences (India)

    The minimum stress and minimum stress difference are shown in equal double pumping. 4. Conclusion. In the present work, the temperature distribution and thermal stress of the actual double-end-pumped Nd:YVO4 cubic crystal have been discussed. The results show that by considering the input power as a constant, the ...

  19. Thermal dimension of quantum spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Amelino-Camelia, Giovanni, E-mail: amelino@roma1.infn.it [Dipartimento di Fisica, Università “La Sapienza” and Sez. Roma1 INFN, P.le A. Moro 2, 00185 Roma (Italy); Brighenti, Francesco [Theoretical Physics, Blackett Laboratory, Imperial College, London, SW7 2BZ (United Kingdom); Dipartimento di Fisica e Astronomia dell' Università di Bologna and Sez. Bologna INFN, Via Irnerio 46, 40126 Bologna (Italy); Gubitosi, Giulia [Theoretical Physics, Blackett Laboratory, Imperial College, London, SW7 2BZ (United Kingdom); Santos, Grasiele [Dipartimento di Fisica, Università “La Sapienza” and Sez. Roma1 INFN, P.le A. Moro 2, 00185 Roma (Italy)

    2017-04-10

    Recent results suggest that a crucial crossroad for quantum gravity is the characterization of the effective dimension of spacetime at short distances, where quantum properties of spacetime become significant. This is relevant in particular for various scenarios of “dynamical dimensional reduction” which have been discussed in the literature. We are here concerned with the fact that the related research effort has been based mostly on analyses of the “spectral dimension”, which involves an unphysical Euclideanization of spacetime and is highly sensitive to the off-shell properties of a theory. As here shown, different formulations of the same physical theory can have wildly different spectral dimension. We propose that dynamical dimensional reduction should be described in terms of the “thermal dimension” which we here introduce, a notion that only depends on the physical content of the theory. We analyze a few models with dynamical reduction both of the spectral dimension and of our thermal dimension, finding in particular some cases where thermal and spectral dimension agree, but also some cases where the spectral dimension has puzzling properties while the thermal dimension gives a different and meaningful picture.

  20. Thermal dimension of quantum spacetime

    Directory of Open Access Journals (Sweden)

    Giovanni Amelino-Camelia

    2017-04-01

    Full Text Available Recent results suggest that a crucial crossroad for quantum gravity is the characterization of the effective dimension of spacetime at short distances, where quantum properties of spacetime become significant. This is relevant in particular for various scenarios of “dynamical dimensional reduction” which have been discussed in the literature. We are here concerned with the fact that the related research effort has been based mostly on analyses of the “spectral dimension”, which involves an unphysical Euclideanization of spacetime and is highly sensitive to the off-shell properties of a theory. As here shown, different formulations of the same physical theory can have wildly different spectral dimension. We propose that dynamical dimensional reduction should be described in terms of the “thermal dimension” which we here introduce, a notion that only depends on the physical content of the theory. We analyze a few models with dynamical reduction both of the spectral dimension and of our thermal dimension, finding in particular some cases where thermal and spectral dimension agree, but also some cases where the spectral dimension has puzzling properties while the thermal dimension gives a different and meaningful picture.

  1. Transient thermal camouflage and heat signature control

    Science.gov (United States)

    Yang, Tian-Zhi; Su, Yishu; Xu, Weikai; Yang, Xiao-Dong

    2016-09-01

    Thermal metamaterials have been proposed to manipulate heat flux as a new way to cloak or camouflage objects in the infrared world. To date, however, thermal metamaterials only operate in the steady-state and exhibit detectable, transient heat signatures. In this letter, the theoretical basis for a thermal camouflaging technique with controlled transient diffusion is presented. This technique renders an object invisible in real time. More importantly, the thermal camouflaging device instantaneously generates a pre-designed heat signature and behaves as a perfect thermal illusion device. A metamaterial coating with homogeneous and isotropic thermal conductivity, density, and volumetric heat capacity was fabricated and very good camouflaging performance was achieved.

  2. Thermal Properties of G-348 Graphite

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, Donald M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Swank, W. David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cottle, David L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Valentin, Francisco I. [City Univ. (CUNY), NY (United States)

    2017-04-01

    Fundamental measurements have been obtained in the INL Graphite Characterization Laboratory to deduce the temperature dependence of thermal conductivity for G-348 isotropic graphite, which has been used by City College of New York in thermal experiments related to gas-cooled nuclear reactors. Measurements of thermal diffusivity, mass, volume and thermal expansion were converted to thermal conductivity in accordance with ASTM Standard Practice C781-08 (R-2014). Data are tabulated and a preliminary correlation for the thermal conductivity is presented as a function of temperature from laboratory temperature to 1000C.

  3. Fire suppression as a thermal implosion

    Science.gov (United States)

    Novozhilov, Vasily

    2017-01-01

    The present paper discusses the possibility of the thermal implosion scenario. This process would be a reverse of the well known thermal explosion (autoignition) phenomenon. The mechanism for thermal implosion scenario is proposed which involves quick suppression of the turbulent diffusion flame. Classical concept of the thermal explosion is discussed first. Then a possible scenario for the reverse process (thermal implosion) is discussed and illustrated by a relevant mathematical model. Based on the arguments presented in the paper, thermal implosion may be observed as an unstable equilibrium point on the generalized Semenov diagram for turbulent flame, however this hypothesis requires ultimate experimental confirmation.

  4. Solar energy thermalization and storage device

    Science.gov (United States)

    McClelland, J.F.

    A passive solar thermalization and thermal energy storage assembly which is visually transparent is described. The assembly consists of two substantial parallel, transparent wall members mounted in a rectangular support frame to form a liquid-tight chamber. A semitransparent thermalization plate is located in the chamber, substantially paralled to and about equidistant from the transparent wall members to thermalize solar radiation which is stored in a transparent thermal energy storage liquid which fills the chamber. A number of the devices, as modules, can be stacked together to construct a visually transparent, thermal storage wall for passive solar-heated buildings.

  5. Software for Automated Generation of Reduced Thermal Models for Spacecraft Thermal Control Project

    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...

  6. Non-Fourier based thermal-mechanical tissue damage prediction for thermal ablation.

    Science.gov (United States)

    Li, Xin; Zhong, Yongmin; Smith, Julian; Gu, Chengfan

    2017-01-02

    Prediction of tissue damage under thermal loads plays important role for thermal ablation planning. A new methodology is presented in this paper by combing non-Fourier bio-heat transfer, constitutive elastic mechanics as well as non-rigid motion of dynamics to predict and analyze thermal distribution, thermal-induced mechanical deformation and thermal-mechanical damage of soft tissues under thermal loads. Simulations and comparison analysis demonstrate that the proposed methodology based on the non-Fourier bio-heat transfer can account for the thermal-induced mechanical behaviors of soft tissues and predict tissue thermal damage more accurately than classical Fourier bio-heat transfer based model.

  7. Corrosion and alteration of materials from the nuclear industry; La Corrosion et l'alteration des materiaux du nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Beauvy, M.; Berthoud, G.; Defranceschi, M.; Ducros, G.; Feron, D.; Guerin, Y.; Latge, C.; Limoge, Y.; Madic, C.; Santarini, G.; Seiler, J.M.; Vernaz, E.; Richet, C.

    2010-07-01

    , testing means, experimental techniques, internal corrosion of zircaloy sheath - the iodine effect, stress corrosion of nickel alloys - hydrogen influence, stress corrosion of stainless steels; C - wear corrosion: a coupled phenomenon, research in the framework of service life extension of the French electronuclear park; 3 - Corrosion in future reactors: A - corrosion in gas reactors: corrosion by helium impurities, oxidation resistance of silicon carbide, corrosion of graphite and carbon-carbon composites; B - corrosion in liquid metal reactors: sodium FBRs, lead and lead alloys reactors; C- corrosion in molten salt reactors: corrosion of Hastelloy N-type nickel alloys by molten fluorides, mass transfer in aniso-thermal fluoride systems, tellurium embrittlement, electrochemical study of pure metals corrosion in molten fluorides; 4 - Materials corrosion and alteration in the back-end of the fuel cycle: A - corrosion in concentrated nitric environment: materials behaviour, self-catalytic mechanism of nitric acid reduction; B - corrosion in unsaturated aqueous environment: metallic corrosion in unsaturated environment - application to the storage of waste containers, bitumens alteration, reinforced concrete behaviour and iron framework corrosion, concrete behaviour in severe thermal environment; C - Corrosion in saturated aqueous environment: metals corrosion in clayey environment, long-term behaviour of glasses, ceramics alteration, underwater concrete durability, clays transformation; D - materials biodegradation: microorganisms and nuclear wastes, biodegradation of bitumen, concretes and steels; 5 - Conclusion, glossary

  8. Advanced thermally stable jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.

    1999-01-31

    The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume

  9. Ballistic Thermal Transfer in Nanosystems

    Directory of Open Access Journals (Sweden)

    A. A. Barinov

    2016-01-01

    Full Text Available This work is concerned with analysis of cross-plane thermal transfer in nanofilms.The paper presents a developed general model of phonon radiation transfer (EPRT based on the Boltzmann transport equation. The EPRT model assumes that the thermal transfer inside a dielectric or metal medium between two metal walls is maintained at different temperatures. These walls are like heat reservoirs; their surfaces are blackbodies. The paper first presents a model of the phonon radiation transfer of the absolute blackbodies in a wide range of temperatures where a model of the ballistic thermal transfer is applicable. It conducts a comparative analysis between phonon radiation transfer and electromagnetic radiation.The basic equation is a formula to calculate a phonon radiation intensity of the absolute blackbody depending on the temperature. Therefore, the formula for the total intensity of phonons is similar to the Stefan-Boltzmann law. The main difference of phonon radiation transfer is that a value of the phonon Stefan-Boltzmann constant is affected by temperature and properties of materials (average acoustic waves in solid bodies and Debye temperature. This can be seen from the curves for Si, Ge, and Diamond.The paper presents a received analytical equation for effective thermal conductivity using a heat flux in a cross-plane direction. The results obtained show the size and temperature dependences of the effective thermal conductivity of silicon, germanium and diamond nanofilms for the ballistic transport in the cross-plane direction. Finally, the paper compares the calculated results with those of available models of different foreign authors, which are in good compliance.

  10. Tailoring thermal interfaces with nanomaterials

    Science.gov (United States)

    Seshadri, Indira

    Thermal interfaces are key to ensure the reliable performance of many semiconductor, energy and electronic systems. High thermal conductivity (k), low elastic modulus (E) interface materials are required to dissipate heat and relieve thermo-mechanical stresses. The aim of this thesis is to develop compliant, high k nanocomposite materials for thermal interface applications utilizing nanostructured networks. Realizing high k nanocomposites is a challenge because of difficulties in incorporating high fractions of uniformly dispersed nanofillers and countering low filler-matrix interfacial conductance, while retaining a low elastic modulus. In this thesis, it is demonstrated that these issues are obviated by using cold welded gold nanowire fillers to obtain an unprecedented 30-fold increase in polydimethylsiloxane thermal conductivity that is 6-fold higher than previously reported nanocomposites at low nanofiller loadings and exceeds theoretical predictions. The nanowire diameter and aspect ratio are key to obtain cold-welded networks that enhance k at low filler fractions, while fostering low E. Along with high k, tailoring high thermal contact conductance G c is crucial for many applications. This thesis reveals a critical correlation between the rheological behavior of a high k gold-nanowire-filled polydimethylsiloxane nanocomposite and its thermal contact conductance with copper. At a critical filler fraction, an abrupt increase in the nanocomposite k is accompanied by a liquid-solid transition and a multifold decrease in Gc. These concurrent changes are attributed to nanowire percolation network formation and pre-cure polymer gelation that inhibits the formation of conformal void-free interfaces. These findings will be important for designing processing sequences to realize heterointerfaces with nanowire filled high k nanocomposite materials. Another important finding of this thesis is that nanowire networks can result in mechanical softening of polymer matrices

  11. Postural Stability is Altered by Blood Shift

    Science.gov (United States)

    Marais, M.; Denise, P.; Guincetre, J. Y.; Normand, H.

    2008-06-01

    Non-vestibular influences as shift in blood volume changed perception of body posture. Then, factors affecting blood shift may alter postural control. The purpose of our study was to investigate the effects of leg venous contention on postural stability. Twelve subjects were studied on a balance plate for 5 minutes with the eyes closed, in 3 conditions: with no leg venous contention or grade 1 and 3 support stockings. Standard deviation of x and y position was calculated before and after the closure of the eyes. Strong venous contention altered postural stability, after the eyes were closed, during the first 10 s of standing. As support stockings prevent blood shift induced by upright posture, this result is in line with the hypothesis that blood shifts influence the perception of body orientation and postural control among others factors as vision, vestibular inputs... This strong venous contention could induce an increase of fall.

  12. Siliceous microfossil extraction from altered Monterey rocks

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, C.O.; Casey, R.E.

    1986-04-01

    Samples of altered Monterey rocks of differing lithologies were processed by various methods to develop new techniques for extracting siliceous microfossils. The preliminary use of thin sections made from the same rocks reduced the number of probable samples (samples worth further processing) by about one-third. Most of the siliceous microfossils contained in altered Monterey rocks appear to be highly recrystallized and are extremely fragile; however, some contained silicified and silica-infilled radiolarians and planktonic and benthonic foraminifera, which are very tough. In general the most useful techniques were gently hydrochloric acid, hydrogen peroxide, formic acid, monosodium glutamate, and regular siliceous microfossil extraction techniques. Unsuccessful techniques and a new siliceous microfossil flotation technique are also documented.

  13. Molecular alterations and biomarkers in colorectal cancer

    Science.gov (United States)

    Grady, William M.; Pritchard, Colin C.

    2013-01-01

    The promise of precision medicine is now a clinical reality. Advances in our understanding of the molecular genetics of colorectal cancer genetics is leading to the development of a variety of biomarkers that are being used as early detection markers, prognostic markers, and markers for predicting treatment responses. This is no more evident than in the recent advances in testing colorectal cancers for specific molecular alterations in order to guide treatment with the monoclonal antibody therapies cetuximab and panitumumab, which target the epidermal growth factor receptor (EGFR). In this review, we update a prior review published in 2010 and describe our current understanding of the molecular pathogenesis of colorectal cancer and how these alterations relate to emerging biomarkers for early detection and risk stratification (diagnostic markers), prognosis (prognostic markers), and the prediction of treatment responses (predictive markers). PMID:24178577

  14. Genetic and molecular alterations across medulloblastoma subgroups.

    Science.gov (United States)

    Skowron, Patryk; Ramaswamy, Vijay; Taylor, Michael D

    2015-10-01

    Medulloblastoma is the most common malignant brain tumour diagnosed in children. Over the last few decades, advances in radiation and chemotherapy have significantly improved the odds of survival. Nevertheless, one third of all patients still succumb to their disease, and many long-term survivors are afflicted with neurocognitive sequelae. Large-scale multi-institutional efforts have provided insight into the transcriptional and genetic landscape of medulloblastoma. Four distinct subgroups of medulloblastoma have been identified, defined by distinct transcriptomes, genetics, demographics and outcomes. Integrated genomic profiling of each of these subgroups has revealed distinct genetic alterations, driving pathways and in some instances cells of origin. In this review, we highlight, in a subgroup-specific manner, our current knowledge of the genetic and molecular alterations in medulloblastoma and underscore the possible avenues for future therapeutic intervention.

  15. Metabolic alterations in renal cell carcinoma.

    Science.gov (United States)

    Massari, Francesco; Ciccarese, Chiara; Santoni, Matteo; Brunelli, Matteo; Piva, Francesco; Modena, Alessandra; Bimbatti, Davide; Fantinel, Emanuela; Santini, Daniele; Cheng, Liang; Cascinu, Stefano; Montironi, Rodolfo; Tortora, Giampaolo

    2015-11-01

    Renal cell carcinoma (RCC) is a metabolic disease, being characterized by the dysregulation of metabolic pathways involved in oxygen sensing (VHL/HIF pathway alterations and the subsequent up-regulation of HIF-responsive genes such as VEGF, PDGF, EGF, and glucose transporters GLUT1 and GLUT4, which justify the RCC reliance on aerobic glycolysis), energy sensing (fumarate hydratase-deficient, succinate dehydrogenase-deficient RCC, mutations of HGF/MET pathway resulting in the metabolic Warburg shift marked by RCC increased dependence on aerobic glycolysis and the pentose phosphate shunt, augmented lipogenesis, and reduced AMPK and Krebs cycle activity) and/or nutrient sensing cascade (deregulation of AMPK-TSC1/2-mTOR and PI3K-Akt-mTOR pathways). We analyzed the key metabolic abnormalities underlying RCC carcinogenesis, highlighting those altered pathways that may represent potential targets for the development of more effective therapeutic strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Rheological and thermal behavior of food matrices during processing and storage: relevance for textural and nutritional quality of food

    NARCIS (Netherlands)

    Renzetti, S.; Jurgens, A.

    2016-01-01

    During processing, foods undergo several transformations which result in their final food structure and textural sensory properties. The rheological and thermal behavior of the food matrices are essential elements in such transformations and in determining the end product properties. When altering

  17. Altered Sensory Feedbacks in Pianist's Dystonia: the altered auditory feedback paradigm and the glove effect

    Directory of Open Access Journals (Sweden)

    Felicia Pei-Hsin Cheng

    2013-12-01

    Full Text Available Background: This study investigates the effect of altered auditory feedback (AAF in musician's dystonia (MD and discusses whether altered auditory feedback can be considered as a sensory trick in MD. Furthermore, the effect of AAF is compared with altered tactile feedback, which can serve as a sensory trick in several other forms of focal dystonia. Methods: The method is based on scale analysis (Jabusch et al. 2004. Experiment 1 employs synchronization paradigm: 12 MD patients and 25 healthy pianists had to repeatedly play C-major scales in synchrony with a metronome on a MIDI-piano with 3 auditory feedback conditions: 1. normal feedback; 2. no feedback; 3. constant delayed feedback. Experiment 2 employs synchronization-continuation paradigm: 12 MD patients and 12 healthy pianists had to repeatedly play C-major scales in two phases: first in synchrony with a metronome, secondly continue the established tempo without the metronome. There are 4 experimental conditions, among them 3 are the same altered auditory feedback as in Experiment 1 and 1 is related to altered tactile sensory input. The coefficient of variation of inter-onset intervals of the key depressions was calculated to evaluate fine motor control. Results: In both experiments, the healthy controls and the patients behaved very similarly. There is no difference in the regularity of playing between the two groups under any condition, and neither did AAF nor did altered tactile feedback have a beneficial effect on patients’ fine motor control. Conclusions: The results of the two experiments suggest that in the context of our experimental designs, AAF and altered tactile feedback play a minor role in motor coordination in patients with musicians' dystonia. We propose that altered auditory and tactile feedback do not serve as effective sensory tricks and may not temporarily reduce the symptoms of patients suffering from MD in this experimental context.

  18. Altered fibroblast proteoglycan production in COPD.

    Science.gov (United States)

    Hallgren, Oskar; Nihlberg, Kristian; Dahlbäck, Magnus; Bjermer, Leif; Eriksson, Leif T; Erjefält, Jonas S; Löfdahl, Claes-Göran; Westergren-Thorsson, Gunilla

    2010-05-11

    Airway remodeling in COPD includes reorganization of the extracellular matrix. Proteoglycans play a crucial role in this process as regulators of the integrity of the extracellular matrix. Altered proteoglycan immunostaining has been demonstrated in COPD lungs and this has been suggested to contribute to the pathogenesis. The major cell type responsible for production and maintenance of ECM constituents, such as proteoglycans, are fibroblasts. Interestingly, it has been proposed that central airways and alveolar lung parenchyma contain distinct fibroblast populations. This study explores the hypothesis that altered depositions of proteoglycans in COPD lungs, and in particular versican and perlecan, is a result of dysregulated fibroblast proteoglycan production. Proliferation, proteoglycan production and the response to TGF-beta1 were examined in vitro in centrally and distally derived fibroblasts isolated from COPD patients (GOLD stage IV) and from control subjects. Phenotypically different fibroblast populations were identified in central airways and in the lung parenchyma. Versican production was higher in distal fibroblasts from COPD patients than from control subjects (p proteoglycan production in distally derived fibroblasts from COPD patients and control subjects. In contrast, centrally derived fibroblasts from COPD patients were less responsive to TGF-beta1 than those from control subjects. The results show that fibroblasts from COPD patients have alterations in proteoglycan production that may contribute to disease development. Distally derived fibroblasts from COPD patients have enhanced production of versican that may have a negative influence on the elastic recoil. In addition, a lower perlecan production in centrally derived fibroblasts from COPD patients may indicate alterations in bronchial basement membrane integrity in severe COPD.

  19. Ocean acidification alters fish–jellyfish symbiosis

    Science.gov (United States)

    Nagelkerken, Ivan; Pitt, Kylie A.; Rutte, Melchior D.; Geertsma, Robbert C.

    2016-01-01

    Symbiotic relationships are common in nature, and are important for individual fitness and sustaining species populations. Global change is rapidly altering environmental conditions, but, with the exception of coral–microalgae interactions, we know little of how this will affect symbiotic relationships. We here test how the effects of ocean acidification, from rising anthropogenic CO2 emissions, may alter symbiotic interactions between juvenile fish and their jellyfish hosts. Fishes treated with elevated seawater CO2 concentrations, as forecast for the end of the century on a business-as-usual greenhouse gas emission scenario, were negatively affected in their behaviour. The total time that fish (yellowtail scad) spent close to their jellyfish host in a choice arena where they could see and smell their host was approximately three times shorter under future compared with ambient CO2 conditions. Likewise, the mean number of attempts to associate with jellyfish was almost three times lower in CO2-treated compared with control fish, while only 63% (high CO2) versus 86% (control) of all individuals tested initiated an association at all. By contrast, none of three fish species tested were attracted solely to jellyfish olfactory cues under present-day CO2 conditions, suggesting that the altered fish–jellyfish association is not driven by negative effects of ocean acidification on olfaction. Because shelter is not widely available in the open water column and larvae of many (and often commercially important) pelagic species associate with jellyfish for protection against predators, modification of the fish–jellyfish symbiosis might lead to higher mortality and alter species population dynamics, and potentially have flow-on effects for their fisheries. PMID:27358374

  20. Serotonergic Hallucinogen-Induced Visual Perceptual Alterations.

    Science.gov (United States)

    Kometer, Michael; Vollenweider, Franz X

    2016-11-30

    Serotonergic hallucinogens, such as lysergic acid diethylamide (LSD), psilocybin, and N,N-dimethyltryptamine (DMT), are famous for their capacity to temporally and profoundly alter an individual's visual experiences. These visual alterations show consistent attributes despite large inter- and intra-individual variances. Many reports document a common perception of colors as more saturated, with increased brightness and contrast in the environment ("Visual Intensifications"). Environmental objects might be altered in size ("Visual illusions") or take on a modified and special meaning for the subject ("Altered self-reference"). Subjects may perceive light flashes or geometrical figures containing recurrent patterns ("Elementary imagery and hallucinations") influenced by auditory stimuli ("Audiovisual synesthesia"), or they may envision images of people, animals, or landscapes ("Complex imagery and hallucinations") without any physical stimuli supporting their percepts. This wide assortment of visual phenomena suggests that one single neuropsychopharmacological mechanism is unlikely to explain such vast phenomenological diversity. Starting with mechanisms that act at the cellular level, the key role of 5-HT2A receptor activation and the subsequent increased cortical excitation will be considered. Next, it will be shown that area specific anatomical and dynamical features link increased excitation to the specific visual contents of hallucinations. The decrease of alpha oscillations by hallucinogens will then be introduced as a systemic mechanism for amplifying internal-driven excitation that overwhelms stimulus-induced excitations. Finally, the hallucinogen-induced parallel decrease of the N170 visual evoked potential and increased medial P1 potential will be discussed as key mechanisms for inducing a dysbalance between global integration and early visual gain that may explain several hallucinogen-induced visual experiences, including visual hallucinations, illusions

  1. Altered fibroblast proteoglycan production in COPD

    Directory of Open Access Journals (Sweden)

    Erjefält Jonas S

    2010-05-01

    Full Text Available Abstract Background Airway remodeling in COPD includes reorganization of the extracellular matrix. Proteoglycans play a crucial role in this process as regulators of the integrity of the extracellular matrix. Altered proteoglycan immunostaining has been demonstrated in COPD lungs and this has been suggested to contribute to the pathogenesis. The major cell type responsible for production and maintenance of ECM constituents, such as proteoglycans, are fibroblasts. Interestingly, it has been proposed that central airways and alveolar lung parenchyma contain distinct fibroblast populations. This study explores the hypothesis that altered depositions of proteoglycans in COPD lungs, and in particular versican and perlecan, is a result of dysregulated fibroblast proteoglycan production. Methods Proliferation, proteoglycan production and the response to TGF-β1 were examined in vitro in centrally and distally derived fibroblasts isolated from COPD patients (GOLD stage IV and from control subjects. Results Phenotypically different fibroblast populations were identified in central airways and in the lung parenchyma. Versican production was higher in distal fibroblasts from COPD patients than from control subjects (p 1 triggered similar increases in proteoglycan production in distally derived fibroblasts from COPD patients and control subjects. In contrast, centrally derived fibroblasts from COPD patients were less responsive to TGF-β1 than those from control subjects. Conclusions The results show that fibroblasts from COPD patients have alterations in proteoglycan production that may contribute to disease development. Distally derived fibroblasts from COPD patients have enhanced production of versican that may have a negative influence on the elastic recoil. In addition, a lower perlecan production in centrally derived fibroblasts from COPD patients may indicate alterations in bronchial basement membrane integrity in severe COPD.

  2. Neck muscle fatigue alters upper limb proprioception.

    Science.gov (United States)

    Zabihhosseinian, Mahboobeh; Holmes, Michael W R; Murphy, Bernadette

    2015-05-01

    Limb proprioception is an awareness by the central nervous system (CNS) of the location of a limb in three-dimensional space and is essential for movement and postural control. The CNS uses the position of the head and neck when interpreting the position of the upper limb, and altered input from neck muscles may affect the sensory inputs to the CNS and consequently may impair the awareness of upper limb joint position. The purpose of this study was to determine whether fatigue of the cervical extensors muscles (CEM) using a submaximal fatigue protocol alters the ability to recreate a previously presented elbow angle with the head in a neutral position. Twelve healthy individuals participated. CEM activity was examined bilaterally using surface electromyography, and kinematics of the elbow joint was measured. The fatigue protocol included an isometric neck extension task at 70 % of maximum until failure. Joint position error increased following fatigue, demonstrating a significant main effect of time (F 2, 18 = 19.41, p ≤ 0.0001) for absolute error. No significant differences were found for variable error (F 2, 18 = 0.27, p = 0.76) or constant error (F 2, 18 = 1.16 of time, p ≤ 0.33). This study confirms that fatigue of the CEM can reduce the accuracy of elbow joint position matching. This suggests that altered afferent input from the neck subsequent to fatigue may impair upper limb proprioception.

  3. [Alterations in arterial compliance of dyslipidemic patients].

    Science.gov (United States)

    Clara, Fernando Mario; Corral, Pablo; Blanco, Gustavo Hector; Scandurra, Adriana Graciela; Meschino, Gustavo Javier

    2015-01-01

    We studied the alteration on the distensibility of the arterial walls caused by dyslipidemia LDLc dependent, along the decades of life, by means of a study of the radial artery pulse wave. We made an analysis of the radial artery pulse wave records acquired by means a movement displacement sensor, placed on radial palpation area. We recruited 100 dyslipidemic men without other cardiovascular risk factors, between the 3rd and the 6th decade. We identified the reflected wave in the records and we computed the augmentation index in order to quantify its amplitude and position. This index is useful to assess the endothelial dysfunction. Besides, we defined a velocity coefficient as the ratio between the size of the individuals and the delay time between the peak of the systolic wave and the arrival of the reflected wave. Results were compared against those obtained in a group of 161 healthy volunteers. We found that dyslipidemic patients presented augmentation index values similar to controls until the fourth decade, increasing thereafter with significant differences only in the 6th decade. No significant differences were found in the velocity index in any of the ages studied. We conclude that alterations produced by dyslipidemia take decades to manifest, and they begin affecting the mechanism of vasodilation of distal arteries with highest proportion of smooth muscle, without altering the proximal conduit arteries with more elastin content. Copyright © 2013 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

  4. Obesogenic diets alter metabolism in mice.

    Science.gov (United States)

    Showalter, Megan R; Nonnecke, Eric B; Linderholm, A L; Cajka, Tomas; Sa, Michael R; Lönnerdal, Bo; Kenyon, Nicholas J; Fiehn, Oliver

    2018-01-01

    Obesity and accompanying metabolic disease is negatively correlated with lung health yet the exact mechanisms by which obesity affects the lung are not well characterized. Since obesity is associated with lung diseases as chronic bronchitis and asthma, we designed a series of experiments to measure changes in lung metabolism in mice fed obesogenic diets. Mice were fed either control or high fat/sugar diet (45%kcal fat/17%kcal sucrose), or very high fat diet (60%kcal fat/7% sucrose) for 150 days. We performed untargeted metabolomics by GC-TOFMS and HILIC-QTOFMS and lipidomics by RPLC-QTOFMS to reveal global changes in lung metabolism resulting from obesity and diet composition. From a total of 447 detected metabolites, we found 91 metabolite and lipid species significantly altered in mouse lung tissues upon dietary treatments. Significantly altered metabolites included complex lipids, free fatty acids, energy metabolites, amino acids and adenosine and NAD pathway members. While some metabolites were altered in both obese groups compared to control, others were different between obesogenic diet groups. Furthermore, a comparison of changes between lung, kidney and liver tissues indicated few metabolic changes were shared across organs, suggesting the lung is an independent metabolic organ. These results indicate obesity and diet composition have direct mechanistic effects on composition of the lung metabolome, which may contribute to disease progression by lung-specific pathways.

  5. Public health implications of altered puberty timing.

    Science.gov (United States)

    Golub, Mari S; Collman, Gwen W; Foster, Paul M D; Kimmel, Carole A; Rajpert-De Meyts, Ewa; Reiter, Edward O; Sharpe, Richard M; Skakkebaek, Niels E; Toppari, Jorma

    2008-02-01

    Changes in puberty timing have implications for the treatment of individual children, for the risk of later adult disease, and for chemical testing and risk assessment for the population. Children with early puberty are at a risk for accelerated skeletal maturation and short adult height, early sexual debut, potential sexual abuse, and psychosocial difficulties. Altered puberty timing is also of concern for the development of reproductive tract cancers later in life. For example, an early age of menarche is a risk factor for breast cancer. A low age at male puberty is associated with an increased risk for testicular cancer according to several, but not all, epidemiologic studies. Girls and, possibly, boys who exhibit premature adrenarche are at a higher risk for developing features of metabolic syndrome, including obesity, type 2 diabetes, and cardiovascular disease later in adulthood. Altered timing of puberty also has implications for behavioral disorders. For example, an early maturation is associated with a greater incidence of conduct and behavior disorders during adolescence. Finally, altered puberty timing is considered an adverse effect in reproductive toxicity risk assessment for chemicals. Recent US legislation has mandated improved chemical testing approaches for protecting children's health and screening for endocrine-disrupting agents, which has led to changes in the US Environmental Protection Agency's risk assessment and toxicity testing guidelines to include puberty-related assessments and to the validation of pubertal male and female rat assays for endocrine screening.

  6. Graviresponses of osteocytes under altered gravity

    Science.gov (United States)

    Di, S. M.; Qian, A. R.; Qu, L. N.; Zhang, W.; Wang, Z.; Ding, C.; Li, Y. H.; Ren, H. G.; Shang, P.

    2011-09-01

    Single cell was capable of sensing and responding to alterations of gravity. Osteocytes, as the most abundant cells of the bone tissue playing an important role in the bone mechanotransduction, are very sensitive to mechanical stimuli. However, the effect of altered gravity on osteocytes so far is less known according to the public papers. Further study on this issue will help to verify and develop the theory of how cells perceive and respond to gravity. It also brings new ideas to the study of space bone loss. In our study, Osteocyte-like MLO-Y4 cells were exposed to 30 parabolic flights three times on ZERO-G airbus A300 to investigate the comprehensive effect on osteocytes stimulated by hyper- and hypo-gravity forces. It showed that the cell morphology, as well as cell area and height, was not changed significantly by hyper-gravity and hypo-gravity. However, the cytoskeleton was reorganized. In flight cells, F-actin polymerization was enhanced at the cell periphery and microtubule organizing center disappeared, but no apoptotic feathers were detected. The results of western blot showed that connexin 43 (Cx43) expression was down-regulated, indicating an decrease of gap-junction. In conclusion, hyper- and hypo-gravity stimulation altered the cytoskeleton architecture and suppressed gap-junction of osteocyte-like MLO-Y4 cells.

  7. Alterations of brain activity in fibromyalgia patients.

    Science.gov (United States)

    Sawaddiruk, Passakorn; Paiboonworachat, Sahattaya; Chattipakorn, Nipon; Chattipakorn, Siriporn C

    2017-04-01

    Fibromyalgia is a chronic pain syndrome, characterized by widespread musculoskeletal pain with diffuse tenderness at multiple tender points. Despite intense investigations, the pathophysiology of fibromyalgia remains elusive. Evidence shows that it could be due to changes in either the peripheral or central nervous system (CNS). For the CNS changes, alterations in the high brain area of fibromyalgia patients have been investigated but the definite mechanisms are still unclear. Magnetic Resonance Imaging (MRI) and Functional Magnetic Resonance (fMRI) have been used to gather evidence regarding the changes of brain morphologies and activities in fibromyalgia patients. Nevertheless, due to few studies, limited knowledge for alterations in brain activities in fibromyalgia is currently available. In this review, the changes in brain activity in various brain areas obtained from reports in fibromyalgia patients are comprehensively summarized. Changes of the grey matter in multiple regions such as the superior temporal gyrus, posterior thalamus, amygdala, basal ganglia, cerebellum, cingulate cortex, SII, caudate and putamen from the MRI as well as the increase of brain activities in the cerebellum, prefrontal cortex, anterior cingulate cortex, thalamus, somatosensory cortex, insula in fMRI studies are presented and discussed. Moreover, evidence from pharmacological interventions offering benefits for fibromyalgia patients by reducing brain activity is presented. Because of limited knowledge regarding the roles of brain activity alterations in fibromyalgia, this summarized review will encourage more future studies to elucidate the underlying mechanisms involved in the brains of these patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Impact of biochar addition on thermal properties of a sandy soil: modelling approach

    Science.gov (United States)

    Usowicz, Boguslaw; Lipiec, Jerzy; Lukowski, Mateusz; Bis, Zbigniew; Marczewski, Wojciech; Usowicz, Jerzy

    2017-04-01

    Adding biochar can alter soil thermal properties and increase the water holding capacity and reduce the mineral soil fertilization. Biochar in the soil can determine the heat balance on the soil surface and the temperature distribution in the soil profile through changes in albedo and the thermal properties. Besides, amendment of soil with biochar results in improvement of water retention, fertility and pH that are of importance in sandy and acid soils, widely used in agriculture. In this study we evaluated the effects of wood-derived biochar (0, 10, 20, and 40 Mg ha-1) incorporated to a depth of 0-15 cm on the thermal conductivity, heat capacity, thermal diffusivity and porosity in sandy soil under field conditions. In addition, soil-biochar mixtures of various percentages of biochar were prepared to determine the thermal properties in function of soil water status and density in laboratory. It was shown that a small quantity of biochar added to the soil does not significantly affect all the thermal properties of the soil. Increasing biochar concentration significantly enhanced porosity and decreased thermal conductivity and diffusivity with different rate depending on soil water status. The soil thermal conductivity and diffusivity varied widely and non-linearly with water content for different biochar content and soil bulk density. However, the heat capacity increased with biochar addition and water content linearly and was greater at higher than lower soil water contents. The measured and literature thermal data were compared with those obtained from the analytic model of Zhang et al. (2013) and statistical-physical model (Usowicz et al., 2016) based on soil texture, biochar content, bulk density and water content.

  9. Concentration of bisphenol A in thermal paper

    National Research Council Canada - National Science Library

    Mendum, Ted; Stoler, Emily; VanBenschoten, Helen; Warner, John C

    2011-01-01

    Bisphenol A (BPA) is widely used as a color developer in thermal paper. Thermal paper is ubiquitous in daily life due to its use in cash register receipts, so opportunities for human contact abound...

  10. Graphene surface plasmons mediated thermal radiation

    Science.gov (United States)

    Li, Jiayu; Liu, Baoan; Shen, Sheng

    2018-02-01

    A graphene nanostructure can simultaneously serve as a plasmonic optical resonator and a thermal emitter when thermally heated up. The unique electronic and optical properties of graphene have rendered tremendous potential in the active manipulation of light and the microscopic energy transport in nanostructures. Here we show that the thermally pumped surface plasmonic modes along graphene nanoribbons could dramatically modulate their thermal emission spectra in both near- and far-fields. Based on the fluctuating surface current method implemented by the resistive boundary method, we directly calculate the thermal emission spectrum from single graphene ribbons and vertically paired graphene ribbons. Furthermore, we demonstrate that both the near- and far-field thermal emission from graphene nanostructures can be optimized by tuning the chemical potential of doped graphene. The general guideline to maximize the thermal emission is illustrated by the our recently developed theory on resonant thermal emitters modulated by quasi-normal modes.

  11. Thermal properties of methyltrimethoxysilane aerogel thin films

    Directory of Open Access Journals (Sweden)

    Leandro N. Acquaroli

    2016-10-01

    Full Text Available Aerogels are light and porous solids whose properties, largely determined by their nanostructure, are useful in a wide range of applications, e.g., thermal insulation. In this work, as-deposited and thermally treated air-filled silica aerogel thin films synthesized using the sol-gel method were studied for their thermal properties using the 3-omega technique, at ambient conditions. The thermal conductivity and diffusivity were found to increase as the porosity of the aerogel decreased. Thermally treated films show a clear reduction in thermal conductivity compared with that of as-deposited films, likely due to an increase of porosity. The smallest thermal conductivity and diffusivity found for our aerogels were 0.019 W m−1 K−1 and 9.8 × 10-9 m2 s−1. A model was used to identify the components (solid, gaseous and radiative of the total thermal conductivity of the aerogel.

  12. Chemical and thermal stability of insulin

    DEFF Research Database (Denmark)

    Huus, Kasper; Havelund, Svend; Olsen, Helle B

    2006-01-01

    To study the correlation between the thermal and chemical stability of insulin formulations with various insulin hexamer ligands.......To study the correlation between the thermal and chemical stability of insulin formulations with various insulin hexamer ligands....

  13. Titanium Heat Pipe Thermal Plane Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermacore Inc. proposes an innovative titanium heat pipe thermal plane for passive thermal control of individual cells within a fuel cell stack. The proposed...

  14. Sprayable Thermal Insulation for Cryogenic Tanks Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Sprayable Thermal Insulation for Cryogenic Tanks (STICT) is a thermal management system applied by either an automated or manual spraying process with less...

  15. Multi-Cell Thermal Battery Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The multi-cell thermal battery (MCTB) is a device that can recover a large fraction of the thermal energy from heated regolith and subsequently apply this energy to...

  16. Chemistry, mineralogy and alteration intensity of hydrothermal altered Mt Unzen conduit rocks (Shimabara/Japan)

    Science.gov (United States)

    Hess, Kai-Uwe; Yilmaz, Tim; Gilg, H. Albert; Janots, Emilie; Mayer, Klaus; Nakada, Setsuya; Dingwell, Donald

    2017-04-01

    Investigations were carried out on hydrothermally altered coherent dacitic dykes samples from (USDP-4) drill core at Mt Unzen stratovolcano (Shimabara/Japan). XRF, XRD, EMPA, C-O-isotope, hot-cathode CL and SEM analysis led to insights concerning chemistry, mineralogy, and intensity and type of alteration as well as the origin of carbonate-precipitating fluids. Additionally a textural characterization of the occurring replacement features in the volcanic conduit rocks was performed. The occurrence of the main secondary phases such as chlorite, pyrite, carbonates, and R1 (Reichweite parameter) illite-smectite and kaolinite group minerals indicate a weak to moderate propylitic to phyllic hydrothermal alteration. The dacitic samples of the dykes show different hydrothermal alteration features: (i) carbonate and chlorite pseudomorphs after hornblende as well as core and zonal textures due to replacement of plagioclase by R1 illite-smectite as well as kaolinite group minerals, (ii) colloform banded fracture fillings and fillings in dissolution vugs, and (iii) chlorite, R1 illite-smectite as well as kaolinite group minerals in the groundmass. Late chlorite veins crosscut precipitates of R1 illite-smectite as well as kaolinite group minerals. Carbonates in fractures and in pseudomorphs after hornblende comprise iron-rich dolomite solid solutions ("ankerite") and calcite. Isotopic values indicate a hydrothermal-magmatic origin for the carbonate formation. The chlorite-carbonate-pyrite index (CCPI) and the Ishikawa alteration index (AI), applied to the investigated samples show significant differences (CCPI=52.7-57.8; AI=36.1-40.6) indicating their different degree of alteration. According to Nakada et al., 2005, the C13 to C16 dykes represent the feeder dyke from the latest eruption (1991-1995) whereas C8 represents an earlier dyke feeder dyke from an older eruption. Weakest alteration, which was obtained in samples C16-1-5 and C13-2-5, correlates with the alteration

  17. Degradation Characterization of Thermal Interface Greases

    Energy Technology Data Exchange (ETDEWEB)

    Major, Joshua [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Narumanchi, Sreekant V [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Paret, Paul P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Blackman, Gregory [DuPont; Wong, Arnold [DuPont; Meth, Jeffery [DuPont

    2018-02-12

    Thermal interface materials (TIMs) are used in power electronics packaging to minimize thermal resistance between the heat generating component and the heat sink. Thermal greases are one such class. The conformability and thin bond line thickness (BLT) of these TIMs can potentially provide low thermal resistance throughout the operation lifetime of a component. However, their performance degrades over time due to pump-out and dry-out during thermal and power cycling. The reliability performance of greases through operational cycling needs to be quantified to develop new materials with superior properties. NREL, in collaboration with DuPont, has performed thermal and reliability characterization of several commercially available thermal greases. Initial bulk and contact thermal resistance of grease samples were measured, and then the thermal degradation that occurred due to pump-out and dry-out during temperature cycling was monitored. The thermal resistances of five different grease materials were evaluated using NREL's steady-state thermal resistance tester based on the ASTM test method D5470. Greases were then applied, utilizing a 2.5 cm x 2.5 cm stencil, between invar and aluminum plates to compare the thermomechanical performance of the materials in a representative test fixture. Scanning Acoustic microscopy, thermal, and compositional analyses were performed periodically during thermal cycling from -40 degrees C to 125 degrees C. Completion of this characterization has allowed for a comprehensive evaluation of thermal greases both for their initial bulk and contact thermal performance, as well as their degradation mechanisms under accelerated thermal cycling conditions.

  18. Thermal physics kinetic theory and thermodynamics

    CERN Document Server

    Singh, Devraj; Yadav, Raja Ram

    2016-01-01

    THERMAL PHYSICS: Kinetic Theory and Thermodynamics is designed for undergraduate course in Thermal Physics and Thermodynamics. The book provides thorough understanding of the fundamental principles of the concepts in Thermal Physics. The book begins with kinetic theory, then moves on liquefaction, transport phenomena, the zeroth, first, second and third laws, thermodynamics relations and thermal conduction. The book concluded with radiation phenomenon. KEY FEATURES: * Include exercises * Short Answer Type Questions * Long Answer Type Questions * Numerical Problems * Multiple Choice Questions

  19. Thermal Spray Coatings for Coastal Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, G.R.; Covino, BernardS. Jr.; Cramer, S.D.; Bullard, S.J.

    1997-11-01

    Several protection strategies for coastal infrastructure using thermal-spray technology are presented from research at the Albany Research Center. Thermal-sprayed zinc coatings for anodes in impressed current cathodic protection systems are used to extend the service lives of reinforced concrete bridges along the Oregon coast. Thermal-sprayed Ti is examined as an alternative to the consumable zinc anode. Sealed thermal-sprayed Al is examined as an alternative coating to zinc dust filled polyurethane paint for steel structures.

  20. Degradation Characterization of Thermal Interface Greases

    Energy Technology Data Exchange (ETDEWEB)

    DeVoto, Douglas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Major, Joshua [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Paret, Paul P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Blackman, Gregory S. [DuPont Experimental Station; Wong, Arnold [DuPont Experimental Station; Meth, Jeffery S. [DuPont Experimental Station

    2017-07-27

    Thermal interface materials (TIMs) are used in power electronics packaging to minimize thermal resistance between the heat generating component and the heat sink. Thermal greases are one such class. The conformability and thin bond line thickness (BLT) of these TIMs can potentially provide low thermal resistance throughout the operation lifetime of a component. However, their performance degrades over time due to pump-out and dry-out during thermal and power cycling. The reliability performance of greases through operational cycling needs to be quantified to develop new materials with superior properties. NREL, in collaboration with DuPont, has performed thermal and reliability characterization of several commercially available thermal greases. Initial bulk and contact thermal resistance of grease samples were measured, and then the thermal degradation that occurred due to pump-out and dry-out during temperature cycling was monitored. The thermal resistances of five different grease materials were evaluated using NREL's steady-state thermal resistance tester based on the ASTM test method D5470. Greases were then applied, utilizing a 2.5 cm x 2.5 cm stencil, between invar and aluminum plates to compare the thermomechanical performance of the materials in a representative test fixture. Scanning Acoustic microscopy, thermal, and compositional analyses were performed periodically during thermal cycling from -40 degrees Celcius to 125 degrees Celcius. Completion of this characterization has allowed for a comprehensive evaluation of thermal greases both for their initial bulk and contact thermal performance, as well as their degradation mechanisms under accelerated thermal cycling conditions.

  1. THERMAL DRIFT CHARACTERISTICS OF CAPACITIVE PRESSURE SENSORS

    OpenAIRE

    ABDELAZIZ BEDDIAF; FOUAD KERROUR; SALAH KEMOUCHE

    2016-01-01

    The capacitive pressure sensors based on silicon are characterized by their very high sensitivities and their low power consumption. Nevertheless, their thermal behavior remains more or less unpredictable because they can indicate very high thermal coefficients. The study of the thermal behavior of these sensors is essential to define the parameters that cause the output characteristics drift. In this study, we modeled the thermal behavior of this sensors, using Finite Element Analysis (FE...

  2. PV-enhanced solar thermal power

    OpenAIRE

    Platzer, W.

    2014-01-01

    Solar electricity generation using concentrating solar thermal collectors faces the challenge of strongly decreased levelized electricity costs by photovoltaic power plants. One of the selling points favouring solar thermal power is the possibility to generate dispatchable power. Concepts discussed here are solar hybridization of conventional or biomass thermal power plants. Another option is the use of thermal energy storage (TES) charged with solar heat which allow to drive the generation o...

  3. Degradation Characterization of Thermal Interface Greases: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    DeVoto, Douglas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Major, Joshua [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Paret, Paul P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Blackman, G. S. [DuPont Experimental Station; Wong, A. [DuPont Experimental Station; Meth, J. S. [DuPont Experimental Station

    2017-08-03

    Thermal interface materials (TIMs) are used in power electronics packaging to minimize thermal resistance between the heat generating component and the heat sink. Thermal greases are one such class. The conformability and thin bond line thickness (BLT) of these TIMs can potentially provide low thermal resistance throughout the operation lifetime of a component. However, their performance degrades over time due to pump-out and dry-out during thermal and power cycling. The reliability performance of greases through operational cycling needs to be quantified to develop new materials with superior properties. NREL, in collaboration with DuPont, has performed thermal and reliability characterization of several commercially available thermal greases. Initial bulk and contact thermal resistance of grease samples were measured, and then the thermal degradation that occurred due to pump-out and dry-out during temperature cycling was monitored. The thermal resistances of five different grease materials were evaluated using NREL's steady-state thermal resistance tester based on the ASTM test method D5470. Greases were then applied, utilizing a 2.5 cm x 2.5 cm stencil, between invar and aluminum plates to compare the thermomechanical performance of the materials in a representative test fixture. Scanning Acoustic microscopy, thermal, and compositional analyses were performed periodically during thermal cycling from -40 degrees Celcius to 125 degrees Celcius. Completion of this characterization has allowed for a comprehensive evaluation of thermal greases both for their initial bulk and contact thermal performance, as well as their degradation mechanisms under accelerated thermal cycling conditions.

  4. Solar thermal power systems. Program summary

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    Each of DOE's solar Thermal Power Systems projects funded and/or in existence during FY 1978 is described and the status as of September 30, 1978 is reflected. These projects are divided as follows: small thermal power applications, large thermal power applications, and advanced thermal technology. Also included are: 1978 project summary tables, bibliography, and an alphabetical index of contractors. (MHR)

  5. Influence of textile properties on thermal comfort

    Science.gov (United States)

    Marolleau, A.; Salaun, F.; Dupont, D.; Gidik, H.; Ducept, S.

    2017-10-01

    This study reports on the impact of textile properties on thermal comfort. The fabric weight, thickness, porosity, moisture regain, air permeability and density have been considered and correlated to the thermal and water vapour resistance, permeability index, thermal conductivity and effusivity, and moisture management capacity. Results suggest that moisture transfer is affected by thickness, density and moisture regain whereas thermal transfer by air permeability and density.

  6. Aquifer Thermal Energy Storage for Seasonal Thermal Energy Balance

    Science.gov (United States)

    Rostampour, Vahab; Bloemendal, Martin; Keviczky, Tamas

    2017-04-01

    Aquifer Thermal Energy Storage (ATES) systems allow storing large quantities of thermal energy in subsurface aquifers enabling significant energy savings and greenhouse gas reductions. This is achieved by injection and extraction of water into and from saturated underground aquifers, simultaneously. An ATES system consists of two wells and operates in a seasonal mode. One well is used for the storage of cold water, the other one for the storage of heat. In warm seasons, cold water is extracted from the cold well to provide cooling to a building. The temperature of the extracted cold water increases as it passes through the building climate control systems and then gets simultaneously, injected back into the warm well. This procedure is reversed during cold seasons where the flow direction is reversed such that the warmer water is extracted from the warm well to provide heating to a building. From the perspective of building climate comfort systems, an ATES system is considered as a seasonal storage system that can be a heat source or sink, or as a storage for thermal energy. This leads to an interesting and challenging optimal control problem of the building climate comfort system that can be used to develop a seasonal-based energy management strategy. In [1] we develop a control-oriented model to predict thermal energy balance in a building climate control system integrated with ATES. Such a model however cannot cope with off-nominal but realistic situations such as when the wells are completely depleted, or the start-up phase of newly installed wells, etc., leading to direct usage of aquifer ambient temperature. Building upon our previous work in [1], we here extend the mathematical model for ATES system to handle the above mentioned more realistic situations. Using our improved models, one can more precisely predict system behavior and apply optimal control strategies to manage the building climate comfort along with energy savings and greenhouse gas reductions

  7. Improvement of thermal-stability of enzyme immobilized onto mesoporous zirconia

    Directory of Open Access Journals (Sweden)

    Yuichi Masuda

    2014-03-01

    Thereafter, FDH immobilized on MPZ showed higher catalytic activity than that on MPS. Enhancement of catalytic activity was obtained by improving the substrate affinity derived from interparticle voids of MPZ. In addition, the FDH immobilized on MPZ had a very great higher thermal stability. Further investigation using transmittance Infrared spectroscopy indicated that the high-order structure of the FDH immobilized on MPZ did not get altered after the heat-treatment.

  8. Thermal creep and stress-affected precipitation of 20% cold-worked 316 stainless steel

    Science.gov (United States)

    Puigh, R. J.; Lovell, A. J.; Garner, F. A.

    1984-05-01

    Measurements of the thermal creep of 20% cold-worked 316 stainless stpel have been performed for temperatures from 593 to 760°C, stress levels as high as 138 MPa and exposure times as long as 15,000 hours. The creep strains exhibit a complex behavior arising from the combined action of true creep and stress-affected precipitation of intermetallic phases. The latter process is suspected to be altered by neutron irradiation.

  9. Thermal Transport in Graphene and Graphene Multilayers

    OpenAIRE

    Alexander A. Balandin; Nika, Denis L.

    2015-01-01

    In this paper we review thermal properties of graphene and multilayer graphene and discuss the optothermal technique developed for the thermal conductivity measurements. We also outline different theoretical approaches used for the description of phonon transport in graphene and provide comparison with available experimental thermal conductivity data.

  10. Electric Motor Thermal Management R&D

    Energy Technology Data Exchange (ETDEWEB)

    Bennion, Kevin

    2016-06-07

    Thermal management enables more efficient and cost-effective motors. This Annual Merit Review presentation describes the technical accomplishments and progress in electric motor thermal management R&D over the last year. This project supports a broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management.

  11. Simultaneous measurements of thermal conductivity and diffusivity ...

    Indian Academy of Sciences (India)

    Abstract. Measurements of thermal conductivity and thermal diffusivity of twin pellets of Se80Te20–xInx. (x = 2, 4, 6 and 10) glasses, prepared under a load of 5 tons were carried out at room temperature using transient plane source (TPS) technique. The measured values of both thermal conductivity and diffusivity were used ...

  12. SOME MOISTURE DEPENDENT THERMAL PROPERTIES AND ...

    African Journals Online (AJOL)

    The thermal heat conductivity, specific heat capacity, thermal heat diffusivity and bulk density of Prosopis africana seeds were determined as a function of moisture content. Specific heat capacity was measured by the method of mixture while the thermal heat conductivity was measured by the guarded hot plate method.

  13. The Thermal Entropy Density of Spacetime

    Directory of Open Access Journals (Sweden)

    Rongjia Yang

    2013-01-01

    Full Text Available Introducing the notion of thermal entropy density via the first law of thermodynamics and assuming the Einstein equation as an equation of thermal state, we obtain the thermal entropy density of any arbitrary spacetime without assuming a temperature or a horizon. The results confirm that there is a profound connection between gravity and thermodynamics.

  14. Thermal Expansion of Hafnium Carbide

    Science.gov (United States)

    Grisaffe, Salvatore J.

    1960-01-01

    Since hafnium carbide (HfC) has a melting point of 7029 deg. F, it may have many high-temperature applications. A literature search uncovered very little information about the properties of HfC, and so a program was initiated at the Lewis Research Center to determine some of the physical properties of this material. This note presents the results of the thermal expansion investigation. The thermal-expansion measurements were made with a Gaertner dilatation interferometer calibrated to an accuracy of +/- 1 deg. F. This device indicates expansion by the movement of fringes produced by the cancellation and reinforcement of fixed wave-length light rays which are reflected from the surfaces of two parallel quartz glass disks. The test specimens which separate these disks are three small cones, each approximately 0.20 in. high.

  15. Pratt & Whitney thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Bornstein, N. [United Technologies Research Center, East Hartford, CT (United States); Marcin, J. [Pratt & Whitney Aircraft Co., East Hartford, CT (United States)

    1995-10-01

    The objective of the Advanced Turbine Systems (ATS) Program is to develop ultra-high efficient, environmentally superior, and cost competitive gas turbine systems. The operating profiles of these industrial gas turbines are long, less cyclic with fewer transients-compared with those for aircraft gas turbine engines. Therefore, creep rather than thermal fatigue, becomes primary life-limiting for hot section components. Thermal barrier coatings (TBCs) will be used to achieve the objectives of the program. TBCs allow surface temperatures to increase without compromising the structural properties of the alloy. TBCs typically consist of a ceramic insulating layer, deposited onto the substrate with an intervening metallic layer, which imparts oxidation protection to the substrate and provides a surface to which the ceramic layer can adhere.

  16. Claisen thermally rearranged (CTR) polymers

    Science.gov (United States)

    Tena, Alberto; Rangou, Sofia; Shishatskiy, Sergey; Filiz, Volkan; Abetz, Volker

    2016-01-01

    Thermally rearranged (TR) polymers, which are considered the next-generation of membrane materials because of their excellent transport properties and high thermal and chemical stability, are proven to have significant drawbacks because of the high temperature required for the rearrangement and low degree of conversion during this process. We demonstrate that using a [3,3]-sigmatropic rearrangement, the temperature required for the rearrangement of a solid glassy polymer was reduced by 200°C. Conversions of functionalized polyimide to polybenzoxazole of more than 97% were achieved. These highly mechanically stable polymers were almost five times more permeable and had more than two times higher degrees of conversion than the reference polymer treated under the same conditions. Properties of these second-generation TR polymers provide the possibility of preparing efficient polymer membranes in a form of, for example, thin-film composite membranes for various gas and liquid membrane separation applications. PMID:27482538

  17. Reproduction alters oxidative status when it is traded-off against longevity.

    Science.gov (United States)

    Beaulieu, Michaël; Geiger, Rina E; Reim, Elisabeth; Zielke, Luisa; Fischer, Klaus

    2015-07-01

    Oxidative stress has been proposed to mediate one of the most important aspects of life-history evolution: the trade-off between reproduction and self-maintenance. However, empirical studies have cast doubt on the generality of this intriguing notion. Here, we hypothesize that reproduction alters oxidative status only when a trade-off between reproduction and self-maintenance occurs. Accordingly, in female Bicyclus anynana butterflies, we found that reproduction affected oxidative markers only under challenging thermal conditions that made the trade-off between reproduction and longevity emerge. Interestingly, under such conditions, butterflies favored longevity over reproduction, suggesting that self-maintenance mechanisms were activated. Accordingly, butterflies reproducing under challenging thermal conditions exhibited enhanced antioxidant defenses and stable oxidative damage. Altogether, our results indicate that a trade-off between reproduction and self-maintenance is indeed a necessary condition for reproduction to alter oxidative status, and that the effects of such a trade-off on oxidative status depend on whether priority is given to self-maintenance or reproduction. Assessing the existence of the trade-off between self-maintenance and reproduction, and whether self-maintenance is prioritized relative to reproduction is therefore crucial for understanding variation in oxidative status in reproducing animals, which may clarify the general implication of oxidative stress in the resolution of life-history trade-offs. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  18. Thermal conductivity of a two-dimensional phosphorene sheet: a comparative study with graphene.

    Science.gov (United States)

    Hong, Yang; Zhang, Jingchao; Huang, Xiaopeng; Zeng, Xiao Cheng

    2015-11-28

    A recently discovered two-dimensional (2D) layered material phosphorene has attracted considerable interest as a promising p-type semiconducting material. In this work, thermal conductivity (κ) of monolayer phosphorene is calculated using large-scale classical non-equilibrium molecular dynamics (NEMD) simulations. The predicted thermal conductivities for infinite length armchair and zigzag phosphorene sheets are 63.6 and 110.7 W m(-1) K(-1) respectively. The strong anisotropic thermal transport is attributed to the distinct atomic structures at altered chiral directions and direction-dependent group velocities. Thermal conductivities of 2D graphene sheets with the same dimensions are also computed for comparison. The extrapolated κ of the 2D graphene sheet are 1008.5(+37.6)(-37.6) and 1086.9(+59.1)(-59.1) W m(-1) K(-1) in the armchair and zigzag directions, respectively, which are an order of magnitude higher than those of phosphorene. The overall and decomposed phonon density of states (PDOS) are calculated in both structures to elucidate their thermal conductivity differences. In comparison with graphene, the vibrational frequencies that can be excited in phosphorene are severely limited. The temperature effect on the thermal conductivity of phosphorene and graphene sheets is investigated, which reveals a monotonic decreasing trend for both structures.

  19. Evaluation of the cellulite using a thermal infra-red camera.

    Science.gov (United States)

    Nkengne, A; Papillon, A; Bertin, C

    2013-02-01

    Cellulite is usually related to alterations of the microcirculation. Measuring the skin temperature is a mean to assess the skin microvascular plexus. A three-step clinical study was performed in order to develop and to validate the use of an infrared thermal camera for measuring cellulite severity. Thermal images of the thigh were recorded and processed to quantify the thermal homogeneity. The proposed protocol was then validated in three steps. Firstly, the parameters which could influence the skin temperature were identified throw a design of experiment. Secondly, the repeatability and reproducibility of the method was estimated (five subjects, four investigators and five experiments). Finally, thermal images and clinical grading of cellulite was performed on 39 women (21-68 years old), and the correlation between these methods was assessed. All parameters describing the thermal homogeneity were found repeatable and reproducible. The strongest correlation between thermal results and the clinical assessment were observed for Sa (R = 0.53, P cellulite. © 2012 John Wiley & Sons A/S.

  20. Early detection of metabolic and energy disorders by thermal time series stochastic complexity analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lutaif, N.A. [Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP (Brazil); Palazzo, R. Jr [Departamento de Telemática, Faculdade de Engenharia Elétrica e Computação, Universidade Estadual de Campinas, Campinas, SP (Brazil); Gontijo, J.A.R. [Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP (Brazil)

    2014-01-17

    Maintenance of thermal homeostasis in rats fed a high-fat diet (HFD) is associated with changes in their thermal balance. The thermodynamic relationship between heat dissipation and energy storage is altered by the ingestion of high-energy diet content. Observation of thermal registers of core temperature behavior, in humans and rodents, permits identification of some characteristics of time series, such as autoreference and stationarity that fit adequately to a stochastic analysis. To identify this change, we used, for the first time, a stochastic autoregressive model, the concepts of which match those associated with physiological systems involved and applied in male HFD rats compared with their appropriate standard food intake age-matched male controls (n=7 per group). By analyzing a recorded temperature time series, we were able to identify when thermal homeostasis would be affected by a new diet. The autoregressive time series model (AR model) was used to predict the occurrence of thermal homeostasis, and this model proved to be very effective in distinguishing such a physiological disorder. Thus, we infer from the results of our study that maximum entropy distribution as a means for stochastic characterization of temperature time series registers may be established as an important and early tool to aid in the diagnosis and prevention of metabolic diseases due to their ability to detect small variations in thermal profile.