Fluid flow and heat transfer characteristics of an enclosure with fin as a top cover of a solar collector

NASA Astrophysics Data System (ADS)

Ambarita, H.; Ronowikarto, A. D.; Siregar, R. E. T.; Setyawan, E. Y.

2018-03-01

To reduce heat loses in a flat plate solar collector, double glasses cover is employed. Several studies show that the heat loss from the glass cover is still very significant in comparison with other losses. Here, double glasses cover with attached fins is proposed. In the present work, the fluid flow and heat transfer characteristics of the enclosure between the double glass cover are investigated numerically. The objective is to examine the effect of the fin to the heat transfer rate of the cover. Two-dimensional governing equations are developed. The governing equations and the boundary conditions are solved using commercial Computational Fluid Dynamics code. The fluid flow and heat transfer characteristics are plotted, and numerical results are compared with empirical correlation. The results show that the presence of the fin strongly affects the fluid flow and heat transfer characteristics. The fin can reduce the heat transfer rate up to 22.42% in comparison with double glasses cover without fins.

Mathematical modeling of high and low temperature heat pipes

NASA Technical Reports Server (NTRS)

Chi, S. W.

1971-01-01

Following a review of heat and mass transfer theory relevant to heat pipe performance, math models are developed for calculating heat-transfer limitations of high-temperature heat pipes and heat-transfer limitations and temperature gradient of low temperature heat pipes. Calculated results are compared with the available experimental data from various sources to increase confidence in the present math models. Complete listings of two computer programs for high- and low-temperature heat pipes respectively are included. These programs enable the performance to be predicted of heat pipes with wrapped-screen, rectangular-groove, or screen-covered rectangular-groove wick.

Heat Transfer and Fluid Mechanics Institute, 24th, Oregon State University, Corvallis, Ore., June 12-14, 1974, Proceedings

NASA Technical Reports Server (NTRS)

Davis, L. R. (Editor); Wilson, R. E.

1974-01-01

Recent theoretical and experimental studies in heat transfer and fluid mechanics, including some environmental protection investigations, are presented in a number of papers. Some of the topics covered include condensation heat transfer, a model of turbulent momentum and heat transfer at points of separation and reattachment, an explicit scheme for calculations of confined turbulent flows with heat transfer, heat transfer effects on a delta wing in subsonic flow, fluid mechanics of ocean outfalls, thermal plumes from industrial cooling water, a photochemical air pollution model for the Los Angeles air basin, and a turbulence model of diurnal variations in the planetary boundary layer. Individual items are announced in this issue.

Subcontracted activities related to TES for building heating and cooling

NASA Technical Reports Server (NTRS)

Martin, J.

1980-01-01

The subcontract program elements related to thermal energy storage for building heating and cooling systems are outlined. The following factors are included: subcontracts in the utility load management application area; life and stability testing of packaged low cost energy storage materials; and development of thermal energy storage systems for residential space cooling. Resistance storage heater component development, demonstration of storage heater systems for residential applications, and simulation and evaluation of latent heat thermal energy storage (heat pump systems) are also discussed. Application of thermal energy storage for solar application and twin cities district heating are covered including an application analysis and technology assessment of thermal energy storage.

Influence of snow cover changes on surface radiation and heat balance based on the WRF model

NASA Astrophysics Data System (ADS)

Yu, Lingxue; Liu, Tingxiang; Bu, Kun; Yang, Jiuchun; Chang, Liping; Zhang, Shuwen

2017-10-01

The snow cover extent in mid-high latitude areas of the Northern Hemisphere has significantly declined corresponding to the global warming, especially since the 1970s. Snow-climate feedbacks play a critical role in regulating the global radiation balance and influencing surface heat flux exchange. However, the degree to which snow cover changes affect the radiation budget and energy balance on a regional scale and the difference between snow-climate and land use/cover change (LUCC)-climate feedbacks have been rarely studied. In this paper, we selected Heilongjiang Basin, where the snow cover has changed obviously, as our study area and used the WRF model to simulate the influences of snow cover changes on the surface radiation budget and heat balance. In the scenario simulation, the localized surface parameter data improved the accuracy by 10 % compared with the control group. The spatial and temporal analysis of the surface variables showed that the net surface radiation, sensible heat flux, Bowen ratio, temperature and percentage of snow cover were negatively correlated and that the ground heat flux and latent heat flux were positively correlated with the percentage of snow cover. The spatial analysis also showed that a significant relationship existed between the surface variables and land cover types, which was not obviously as that for snow cover changes. Finally, six typical study areas were selected to quantitatively analyse the influence of land cover types beneath the snow cover on heat absorption and transfer, which showed that when the land was snow covered, the conversion of forest to farmland can dramatically influence the net radiation and other surface variables, whereas the snow-free land showed significantly reduced influence. Furthermore, compared with typical land cover changes, e.g., the conversion of forest into farmland, the influence of snow cover changes on net radiation and sensible heat flux were 60 % higher than that of land cover changes, indicating the importance of snow cover changes in the surface-atmospheric feedback system.

Heating and cooling gas-gun targets: nuts and bolts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustavsen, Richard L; Bartram, Brian D; Gehr, Russell J

The nuts and bolts of a system used to heat and cool gas-gun targets is described. We have now used the system for more than 35 experiments, all of which have used electromagnetic gauging. Features of the system include a cover which is removed (remotely) just prior to projectile impact and the widespread use of metal/polymer insulations. Both the cover and insulation were required to obtain uniform temperatures in samples with low thermal conductivity. The use of inexpensive video cameras to make remote observations of the cover removal was found to be very useful. A brief catalog of useful glue,more » adhesive tape, insulation, and seal materials is given.« less

Aerothermodynamic Environments Definition for the Mars Science Laboratory Entry Capsule

NASA Technical Reports Server (NTRS)

Edquist, Karl T.; Dyakonov, Artem A.; Wright, Michael J.; Tang, Chun Y.

2007-01-01

An overview of the aerothermodynamic environments definition status is presented for the Mars Science Laboratory entry vehicle. The environments are based on Navier-Stokes flowfield simulations on a candidate aeroshell geometry and worst-case entry heating trajectories. Uncertainties for the flowfield predictions are based primarily on available ground data since Mars flight data are scarce. The forebody aerothermodynamics analysis focuses on boundary layer transition and turbulent heating augmentation. Turbulent transition is expected prior to peak heating, a first for Mars entry, resulting in augmented heat flux and shear stress at the same heatshield location. Afterbody computations are also shown with and without interference effects of reaction control system thruster plumes. Including uncertainties, analysis predicts that the heatshield may experience peaks of 225 W/sq cm for turbulent heat flux, 0.32 atm for stagnation pressure, and 400 Pa for turbulent shear stress. The afterbody heat flux without thruster plume interference is predicted to be 7 W/sq cm on the backshell and 10 W/sq cm on the parachute cover. If the reaction control jets are fired near peak dynamic pressure, the heat flux at localized areas could reach as high as 76 W/sq cm on the backshell and 38 W/sq cm on the parachute cover, including uncertainties. The final flight environments used for hardware design will be updated for any changes in the aeroshell configuration, heating design trajectories, or uncertainties.

Sensitivity of thermal inertia calculations to variations in environmental factors. [in mapping of Earth's surface by remote sensing

NASA Technical Reports Server (NTRS)

Kahle, A. B.; Alley, R. E.; Schieldge, J. P.

1984-01-01

The sensitivity of thermal inertia (TI) calculations to errors in the measurement or parameterization of a number of environmental factors is considered here. The factors include effects of radiative transfer in the atmosphere, surface albedo and emissivity, variations in surface turbulent heat flux density, cloud cover, vegetative cover, and topography. The error analysis is based upon data from the Heat Capacity Mapping Mission (HCMM) satellite for July 1978 at three separate test sites in the deserts of the western United States. Results show that typical errors in atmospheric radiative transfer, cloud cover, and vegetative cover can individually cause root-mean-square (RMS) errors of about 10 percent (with atmospheric effects sometimes as large as 30-40 percent) in HCMM-derived thermal inertia images of 20,000-200,000 pixels.

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Are duct burners and waste heat... Stationary Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam...

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Are duct burners and waste heat... Stationary Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam...

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Are duct burners and waste heat... Stationary Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam...

Hot hollow cathode gun assembly

DOEpatents

Zeren, J.D.

1983-11-22

A hot hollow cathode deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, the hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

Vacuum vapor deposition gun assembly

DOEpatents

Zeren, Joseph D.

1985-01-01

A vapor deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, a hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

Northeastern Summer Electricity Market Alert

EIA Publications

2013-01-01

The National Weather Service declared an excessive-heat warning for much of the Mid-Atlantic and northeastern United States, including major electric markets covering Philadelphia, Boston, Washington, D.C., and New York City. This report highlights the wholesale electricity market activity occurring in response to the higher-than-normal electricity demand caused by the heat wave.

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 12 2011-07-01 2009-07-01 true Are duct burners and waste heat... Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam generating units...

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Are duct burners and waste heat... Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam generating units...

Loss of sea ice in the Arctic.

PubMed

Perovich, Donald K; Richter-Menge, Jacqueline A

2009-01-01

The Arctic sea ice cover is in decline. The areal extent of the ice cover has been decreasing for the past few decades at an accelerating rate. Evidence also points to a decrease in sea ice thickness and a reduction in the amount of thicker perennial sea ice. A general global warming trend has made the ice cover more vulnerable to natural fluctuations in atmospheric and oceanic forcing. The observed reduction in Arctic sea ice is a consequence of both thermodynamic and dynamic processes, including such factors as preconditioning of the ice cover, overall warming trends, changes in cloud coverage, shifts in atmospheric circulation patterns, increased export of older ice out of the Arctic, advection of ocean heat from the Pacific and North Atlantic, enhanced solar heating of the ocean, and the ice-albedo feedback. The diminishing Arctic sea ice is creating social, political, economic, and ecological challenges.

The joint measuring campaign 1979 in Ruthe (West Germany) description and preliminary data

NASA Technical Reports Server (NTRS)

Vanderploeg, R. R.; Tassone, G.; Vonhoyningen-Huene, J. (Principal Investigator)

1979-01-01

The measurements and observations performed as part of the TELLUS project on soil moisture and heat budget evaluations of selected areas in the vecinity of Ruthe, West Germany are presented and discussed. The main lines of investigation include evapotranspiration and moisture content in bare soils covered by vegetation, interactions between natural phenomena and mesoscale heat budget, and man made changes and their impact on regional heat budget.

Effects of friction and heat conduction on sound propagation in ducts. [analyzing complex aerodynamic noise problems

NASA Technical Reports Server (NTRS)

Huerre, P.; Karamcheti, K.

1976-01-01

The theory of sound propagation is examined in a viscous, heat-conducting fluid, initially at rest and in a uniform state, and contained in a rigid, impermeable duct with isothermal walls. Topics covered include: (1) theoretical formulation of the small amplitude fluctuating motions of a viscous, heat-conducting and compressible fluid; (2) sound propagation in a two dimensional duct; and (3) perturbation study of the inplane modes.

An eddy covariance system to characterize the atmospheric surface layer and turbulent latent heat fluxes over a debris-covered Himalayan glacier.

NASA Astrophysics Data System (ADS)

Litt, Maxime; Steiner, Jakob F.; Stigter, Emmy E.; Immerzeel, Walter; Shea, Joseph Michael

2017-04-01

Over debris-covered glaciers, water content variations in the debris layer can drive significant changes in its thermal conductivity and significantly impact melt rates. Since sublimation and evaporation are favoured in high-altitude conditions, e.g., low atmospheric pressure and high wind speeds, they are expected to strongly influence the water balance of the debris-layer. Dedicated latent heat fluxes measurements at the debris surface are essential to characterize the debris heat conductivity in order to assess underlying ice melt. Furthermore, the contribution of the turbulent fluxes in the surface energy balance over debris covered glacier remains uncertain since they are generally evaluated through similarity methods which might not be valid in complex terrain. We present the first results of a 15-day eddy-covariance experiment installed at the end of the monsoon (September-October) on a 3-m tower above the debris-covered Lirung glacier in Nepal. The tower also included measurements of the 4 radiation components. The eddy covariance measurements allowed for the characterization of the turbulence in the atmospheric surface layer, as well as the direct measurements of evaporation, sublimation and turbulent sensible heat fluxes. The experiment helps us to evaluate the contribution of turbulent fluxes to the surface energy balance over this debris-covered glacier, through a precise characterization of the overlying turbulent atmospheric surface layer. It also helps to study the role of the debris-layer water content changes through evaporation and sublimation and its feedback on heat conduction in this layer. The large observed turbulent fluxes play a significant role in the energy balance at the debris surface and significantly influence debris moisture, conductivity and subsequently underlying ice melt.

Structural complexity and land-surface energy exchange along a gradient from arctic tundra to boreal forest

USGS Publications Warehouse

Thompson, C.; Beringer, J.; Chapin, F. S.; McGuire, A.D.

2004-01-01

Question: Current climate changes in the Alaskan Arctic, which are characterized by increases in temperature and length of growing season, could alter vegetation structure, especially through increases in shrub cover or the movement of treeline. These changes in vegetation structure have consequences for the climate system. What is the relationship between structural complexity and partitioning of surface energy along a gradient from tundra through shrub tundra to closed canopy forest? Location: Arctic tundra-boreal forest transition in the Alaskan Arctic. Methods: Along this gradient of increasing canopy complexity, we measured key vegetation characteristics, including community composition, biomass, cover, height, leaf area index and stem area index. We relate these vegetation characteristics to albedo and the partitioning of net radiation into ground, latent, and sensible heating fluxes. Results: Canopy complexity increased along the sequence from tundra to forest due to the addition of new plant functional types. This led to non-linear changes in biomass, cover, and height in the understory. The increased canopy complexity resulted in reduced ground heat fluxes, relatively conserved latent heat fluxes and increased sensible heat fluxes. The localized warming associated with increased sensible heating over more complex canopies may amplify regional warming, causing further vegetation change in the Alaskan Arctic.

Photovoltaic-thermal collectors

DOEpatents

Cox, III, Charles H.

1984-04-24

A photovoltaic-thermal solar cell including a semiconductor body having antireflective top and bottom surfaces and coated on each said surface with a patterned electrode covering less than 10% of the surface area. A thermal-absorbing surface is spaced apart from the bottom surface of the semiconductor and a heat-exchange fluid is passed between the bottom surface and the heat-absorbing surface.

Computer program for natural gas flow through nozzles

NASA Technical Reports Server (NTRS)

Johnson, R. C.

1972-01-01

Subroutines, FORTRAN 4 type, were developed for calculating isentropic natural gas mass flow rate through nozzle. Thermodynamic functions covering compressibility, entropy, enthalpy, and specific heat are included.

Soldering instrument safety improvements

DOEpatents

Kosslow, William J.; Giron, Ronald W.

1996-01-01

A safe soldering device includes a retractable heat shield which can be moved between a first position in which the solder tip of the device is exposed for soldering operation and a second position in which the solder tip is covered by the heat shield. Preferably, the heat shield is biased towards the second position and may be locked in the first position for ease of use. When the soldering device is equipped with a vacuum system, the heat shield may serve to guide the flow of gases and heat from the solder tip away from the work area. The heat shield is preferably made of non-heatsinking plastic.

Reaching Out.

ERIC Educational Resources Information Center

Porter, Randall C.

1999-01-01

Discusses technology and equipment requirements for developing an effective distance-learning classroom. Areas covered include cabling, the control booth, microphones, acoustics, lighting, heating and air conditioning, cameras, video monitors, staffing, and power requirements. (GR)

Research in solar plasma theory

NASA Technical Reports Server (NTRS)

Vanhoven, Gerard

1992-01-01

The main thrust and significance of our research results are presented. The topics covered include: (1) coronal structure and dynamics; (2) coronal heating; (3) filament formation; and (4) flare energy release.

Geothermal energy systems plan for Boise City

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-01-01

This is a plan for development of a downtown Boise geothermal district space heating system incorporating legal, engineering, organizational, geological, and economic requirements. Topics covered include: resource characteristics, system design and feasibility, economic feasibility, legal overview, organizational alternatives, and conservation. Included in appendices are: property ownership patterns on the Boise Front, existing hot well data, legal briefs, environmental data, decision point communications, typical building heating system retrofit schematics, and background assumptions and data for cost summary. (MHR)

Perioperative thermal insulation.

PubMed

Sessler, D I; McGuire, J; Sessler, A M

1991-05-01

To determine the efficacy of passive insulators advocated for prevention of cutaneous heat loss, we determined heat loss in unanesthetized volunteers covered by one of the following: a cloth "split sheet" surgical drape; a Convertors disposable-paper split sheet; a Thermadrape disposable laparotomy sheet; an unheated Bair Hugger patient-warming blanket; 1.5-mil-thick plastic hamper bags; and a prewarmed, cotton hospital blanket. Cutaneous heat loss was measured using 10 area-weighted thermal flux transducers while volunteers were exposed to a 20.6 degrees C environment for 1 h. Heat loss decreased significantly from 100 +/- 3 W during the control periods to 69 +/- 6 W (average of all covers) after 1 h of treatment. Heat losses from volunteers insulated by the Thermadrape (61 +/- 6 W) and Bair Hugger covers (64 +/- 5 W) were significantly less than losses from those insulated by plastic bags (77 +/- 11 W). The paper drape (67 +/- 7 W) provided slightly, but not significantly, better insulation than the cloth drape (70 +/- 4 W). Coverage by prewarmed cotton blankets initially resulted in the least heat loss (58 +/- 8 W), but after 40 min, resulted in heat loss significantly greater than that for the Thermadrape (71 +/- 7 W). Regional heat loss was roughly proportional to surface area, and the distribution of regional heat loss remained similar with all covers. These data suggest that cost and convenience should be major factors when choosing among passive perioperative insulating covers. It is likely that the amount of skin surface covered is more important than the choice of skin region covered or the choice of insulating material.

Exergie /4th revised and enlarged edition/

NASA Astrophysics Data System (ADS)

Baloh, T.; Wittwer, E.

The theoretical concept of exergy is explained and its practical applications are discussed. Equilibrium and thermal equilibrium are reviewed as background, and exergy is considered as a reference point for solid-liquid, liquid-liquid, and liquid-gas systems. Exergetic calculations and their graphic depictions are covered. The concepts of enthalpy and entropy are reviewed in detail, including their applications to gas mixtures, solutions, and isolated substances. The exergy of gas mixtures, solutions, and isolated substances is discussed, including moist air, liquid water in water vapor, dry air, and saturation-limited solutions. Mollier exergy-enthalpy-entropy diagrams are presented for two-component systems, and exergy losses for throttling, isobaric mixing, and heat transfer are addressed. The relationship of exergy to various processes is covered, including chemical processes, combustion, and nuclear reactions. The optimization of evaporation plants through exergy is discussed. Calculative examples are presented for energy production and heating, industrial chemical processes, separation of liquid air, nuclear reactors, and others.

Los Alamos science, Number 14

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-01-01

Nine authored articles are included covering: natural heat engine, photoconductivity, the Caribbean Basin, energy in Central America, peat, geothermal energy, and the MANIAC computer. Separate abstracts were prepared for the articles. (DLC)

Exposure and Vulnerability Geospatial Analysis Using Earth Observation Data in the City of Liege, Belgium

NASA Astrophysics Data System (ADS)

Stephenne, N.; Beaumont, B.; Hallot, E.; Lenartz, F.; Lefebre, F.; Lauwaet, D.; Poelmans, L.; Wolff, E.

2017-05-01

Risk situation can be mitigated by prevention measures, early warning tools and adequate monitoring of past experiences where Earth Observation and geospatial analysis have an adding value. This paper discusses the potential use of Earth Observation data and especially Land Cover / Land Use map in addressing within the three aspects of the risk assessment: danger, exposure and vulnerability. Evidences of the harmful effects of air pollution or heat waves are widely admitted and should increase in the context of global warming. Moreover, urban areas are generally warmer than rural surroundings, the so-called urban heat island. Combined with in-situ measurements, this paper presents models of city or local climate (air pollution and urban heat island), with a resolution of less than one kilometer, developed by integrating several sources of information including Earth Observation data and in particular Land Cover / Land Use. This assessment of the danger is then be related to a map of exposure and vulnerable people. Using dasymetric method to disaggregate statistical information on Land Cover / Land Use data, the SmartPop project analyzes in parallel the map of danger with the maps of people exposure A special focus on some categories at risk such as the elderly has been proposed by Aubrecht and Ozceylan (2013). Perspectives of the project includes the integration of a new Land Cover / Land Use map in the danger, exposure and vulnerability models and proposition of several aspects of risk assessment with the stakeholders of Wallonia.

WORKING PARK-FUEL CELL COMBINED HEAT AND POWER SYSTEM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allan Jones

2003-09-01

This report covers the aims and objectives of the project which was to design, install and operate a fuel cell combined heat and power (CHP) system in Woking Park, the first fuel cell CHP system in the United Kingdom. The report also covers the benefits that were expected to accrue from the work in an understanding of the full technology procurement process (including planning, design, installation, operation and maintenance), the economic and environmental performance in comparison with both conventional UK fuel supply and conventional CHP and the commercial viability of fuel cell CHP energy supply in the new deregulated energymore » markets.« less

Spray generators for absorption refrigeration systems

DOEpatents

Sibley, Howard W.

1979-06-19

A spray generator for an absorption refrigeration system that includes a heat exchanger comprised of a multiplicity of variably spaced heat exchange tubes. The tubes are spaced close together near the top of the heat exchanger and spaced more widely apart near the bottom of the heat exchanger. Dilute absorbent solution is sprayed down through the heat exchanger. The close nesting of the tubes in the top portion of the heat exchanger retards liquid flow and aids heating of the solution. The wide spacing of the tubes in the lower section of the heat exchanger facilitate vapor flow out of the heat exchanger and eliminates liquid "blow-off". The top tubes are covered by a baffle to prevent the liquid solution from splashing out of the heat exchanger off of these top tubes.

Molten metal holder furnace and casting system incorporating the molten metal holder furnace

DOEpatents

Kinosz, Michael J.; Meyer, Thomas N.

2003-02-11

A bottom heated holder furnace (12) for containing a supply of molten metal includes a storage vessel (30) having sidewalls (32) and a bottom wall (34) defining a molten metal receiving chamber (36). A furnace insulating layer (42) lines the molten metal receiving chamber (36). A thermally conductive heat exchanger block (54) is located at the bottom of the molten metal receiving chamber (36) for heating the supply of molten metal. The heat exchanger block (54) includes a bottom face (65), side faces (66), and a top face (67). The heat exchanger block (54) includes a plurality of electrical heaters (70) extending therein and projecting outward from at least one of the faces of the heat exchanger block (54), and further extending through the furnace insulating layer (42) and one of the sidewalls (32) of the storage vessel (30) for connection to a source of electrical power. A sealing layer (50) covers the bottom face (65) and side faces (66) of the heat exchanger block (54) such that the heat exchanger block (54) is substantially separated from contact with the furnace insulating layer (42).

The Martian climate: Energy balance models with CO2/H2O atmospheres

NASA Technical Reports Server (NTRS)

Hoffert, M. I.

1985-01-01

Coupled equations are developed for mass and heat transport in a seasonal Mars model with condensation and sublimation of CO2 at the polar caps. Topics covered include physical considerations of planetary as mass and energy balance; effects of phase changes at the surface on mass and heat flux; atmospheric transport and governing equations; and numerical analysis.

Heating the Ice-Covered Lakes of the McMurdo Dry Valleys, Antarctica - Decadal Trends in Heat Content, Ice Thickness, and Heat Exchange

NASA Astrophysics Data System (ADS)

Gooseff, M. N.; Priscu, J. C.; Doran, P. T.; Chiuchiolo, A.; Obryk, M.

2014-12-01

Lakes integrate landscape processes and climate conditions. Most of the permanently ice-covered lakes in the McMurdo Dry Valleys, Antarctica are closed basin, receiving glacial melt water from streams for 10-12 weeks per year. Lake levels rise during the austral summer are balanced by sublimation of ice covers (year-round) and evaporation of open water moats (summer only). Vertical profiles of water temperature have been measured in three lakes in Taylor Valley since 1988. Up to 2002, lake levels were dropping, ice covers were thickening, and total heat contents were decreasing. These lakes have been gaining heat since the mid-2000s, at rates as high as 19.5x1014 cal/decade). Since 2002, lake levels have risen substantially (as much as 2.5 m), and ice covers have thinned (1.5 m on average). Analyses of lake ice thickness, meteorological conditions, and stream water heat loads indicate that the main source of heat to these lakes is from latent heat released when ice-covers form during the winter. An aditional source of heat to the lakes is water inflows from streams and direct glacieal melt. Mean lake temperatures in the past few years have stabilized or cooled, despite increases in lake level and total heat content, suggesting increased direct inflow of meltwater from glaciers. These results indicate that McMurdo Dry Valley lakes are sensitive indicators of climate processes in this polar desert landscape and demonstrate the importance of long-term data sets when addressing the effects of climate on ecosystem processes.

Contrasting suspended covers reveal the impact of an artificial monolayer on heat transfer processes at the interfacial boundary layer.

PubMed

Pittaway, P; Martínez-Alvarez, V; Hancock, N

2015-01-01

The highly variable performance of artificial monolayers in reducing evaporation from water storages has been attributed to wind speed and wave turbulence. Other factors operating at the interfacial boundary layer have seldom been considered. In this paper, two physical shade covers differing in porosity and reflectivity were suspended over 10 m diameter water tanks to attenuate wind and wave turbulence. The monolayer octadecanol was applied to one of the covered tanks, and micrometeorological conditions above and below the covers were monitored to characterise diurnal variation in the energy balance. A high downward (air-to-water) convective heat flux developed under the black cover during the day, whereas diurnal variation in the heat flux under the more reflective, wind-permeable white cover was much less. Hourly air and water temperature profiles under the covers over 3 days when forced convection was minimal (low wind speed) were selected for analysis. Monolayer application reduced temperature gain in surface water under a downward convective heat flux, and conversely reduced temperature loss under an upward convective heat flux. This 'dual property' may explain why repeat application of an artificial monolayer to retard evaporative loss (reducing latent heat loss) does not inevitably increase water temperature.

Conservation and Renewable Energy Program: Bibliography, 1988 edition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vaughan, K.H.

The 831 references covering the period 1980 through Feb. 1988, are arranged under the following: analysis and evaluation, building equipment, building thermal envelope systems and materials, community systems and cogeneration, residential conservation service, retrofit, advanced heat engine ceramics, alternative fuels, microemulsion fuels, industrial chemical heat pumps, materials for waste heat utilization, energy conversion and utilization materials, tribology, emergency energy conservation,inventions, electric energy systems, thermal storage, biofuels production, biotechnology, solar technology, geothermal, and continuous chromatography in multicomponent separations. An author index is included.

Summer Thermal Performance of Ventilated Roofs with Tiled Coverings

NASA Astrophysics Data System (ADS)

Bortoloni, M.; Bottarelli, M.; Piva, S.

2017-01-01

The thermal performance of a ventilated pitched roof with tiled coverings is analysed and compared with unventilated roofs. The analysis is carried out by means of a finite element numerical code, by solving both the fluid and thermal problems in steady-state. A whole one-floor building with a pitched roof is schematized as a 2D computational domain including the air-permeability of tiled covering. Realistic data sets for wind, temperature and solar radiation are used to simulate summer conditions at different times of the day. The results demonstrate that the batten space in pitched roofs is an effective solution for reducing the solar heat gain in summer and thus for achieving better indoor comfort conditions. The efficiency of the ventilation is strictly linked to the external wind conditions and to buoyancy forces occurring due to the heating of the tiles.

A conceptual model of oceanic heat transport in the Snowball Earth scenario

NASA Astrophysics Data System (ADS)

Comeau, Darin; Kurtze, Douglas A.; Restrepo, Juan M.

2016-12-01

Geologic evidence suggests that the Earth may have been completely covered in ice in the distant past, a state known as Snowball Earth. This is still the subject of controversy, and has been the focus of modeling work from low-dimensional models up to state-of-the-art general circulation models. In our present global climate, the ocean plays a large role in redistributing heat from the equatorial regions to high latitudes, and as an important part of the global heat budget, its role in the initiation a Snowball Earth, and the subsequent climate, is of great interest. To better understand the role of oceanic heat transport in the initiation of Snowball Earth, and the resulting global ice covered climate state, the goal of this inquiry is twofold: we wish to propose the least complex model that can capture the Snowball Earth scenario as well as the present-day climate with partial ice cover, and we want to determine the relative importance of oceanic heat transport. To do this, we develop a simple model, incorporating thermohaline dynamics from traditional box ocean models, a radiative balance from energy balance models, and the more contemporary "sea glacier" model to account for viscous flow effects of extremely thick sea ice. The resulting model, consisting of dynamic ocean and ice components, is able to reproduce both Snowball Earth and present-day conditions through reasonable changes in forcing parameters. We find that including or neglecting oceanic heat transport may lead to vastly different global climate states, and also that the parameterization of under-ice heat transfer in the ice-ocean coupling plays a key role in the resulting global climate state, demonstrating the regulatory effect of dynamic ocean heat transport.

A Multi-scale Approach to Urban Thermal Analysis

NASA Technical Reports Server (NTRS)

Gluch, Renne; Quattrochi, Dale A.

2005-01-01

An environmental consequence of urbanization is the urban heat island effect, a situation where urban areas are warmer than surrounding rural areas. The urban heat island phenomenon results from the replacement of natural landscapes with impervious surfaces such as concrete and asphalt and is linked to adverse economic and environmental impacts. In order to better understand the urban microclimate, a greater understanding of the urban thermal pattern (UTP), including an analysis of the thermal properties of individual land covers, is needed. This study examines the UTP by means of thermal land cover response for the Salt Lake City, Utah, study area at two scales: 1) the community level, and 2) the regional or valleywide level. Airborne ATLAS (Advanced Thermal Land Applications Sensor) data, a high spatial resolution (10-meter) dataset appropriate for an environment containing a concentration of diverse land covers, are used for both land cover and thermal analysis at the community level. The ATLAS data consist of 15 channels covering the visible, near-IR, mid-IR and thermal-IR wavelengths. At the regional level Landsat TM data are used for land cover analysis while the ATLAS channel 13 data are used for the thermal analysis. Results show that a heat island is evident at both the community and the valleywide level where there is an abundance of impervious surfaces. ATLAS data perform well in community level studies in terms of land cover and thermal exchanges, but other, more coarse-resolution data sets are more appropriate for large-area thermal studies. Thermal response per land cover is consistent at both levels, which suggests potential for urban climate modeling at multiple scales.

Transport Phenomena in Thin Rotating Liquid Films Including: Nucleate Boiling

NASA Technical Reports Server (NTRS)

Faghri, Amir

2005-01-01

In this grant, experimental, numerical and analytical studies of heat transfer in a thin liquid film flowing over a rotating disk have been conducted. Heat transfer coefficients were measured experimentally in a rotating disk heat transfer apparatus where the disk was heated from below with electrical resistance heaters. The heat transfer measurements were supplemented by experimental characterization of the liquid film thickness using a novel laser based technique. The heat transfer measurements show that the disk rotation plays an important role on enhancement of heat transfer primarily through the thinning of the liquid film. Experiments covered both momentum and rotation dominated regimes of the flow and heat transfer in this apparatus. Heat transfer measurements have been extended to include evaporation and nucleate boiling and these experiments are continuing in our laboratory. Empirical correlations have also been developed to provide useful information for design of compact high efficiency heat transfer devices. The experimental work has been supplemented by numerical and analytical analyses of the same problem. Both numerical and analytical results have been found to agree reasonably well with the experimental results on liquid film thickness and heat transfer Coefficients/Nusselt numbers. The numerical simulations include the free surface liquid film flow and heat transfer under disk rotation including the conjugate effects. The analytical analysis utilizes an integral boundary layer approach from which

Handbook of experiences in the design and installation of solar heating and cooling systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, D.S.; Oberoi, H.S.

1980-07-01

A large array of problems encountered are detailed, including design errors, installation mistakes, cases of inadequate durability of materials and unacceptable reliability of components, and wide variations in the performance and operation of different solar systems. Durability, reliability, and design problems are reviewed for solar collector subsystems, heat transfer fluids, thermal storage, passive solar components, piping/ducting, and reliability/operational problems. The following performance topics are covered: criteria for design and performance analysis, domestic hot water systems, passive space heating systems, active space heating systems, space cooling systems, analysis of systems performance, and performance evaluations. (MHR)

Getting Down to Business: Air Conditioning and Heating Service, Module 36. [Student Guide]. Entrepreneurship Training Components.

ERIC Educational Resources Information Center

Sanderson, Barbara

This module on owning and operating an air conditioning and heating service is one of 36 in a series on entrepreneurship. The introduction tells the student what topics will be covered and suggests other modules to read in related occupations. Each unit includes student goals, a case study, and a discussion of the unit subject matter. Learning…

Dampers, reclaimers and pumps - oh my!

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, D.; Wyatt, E.

1997-07-01

Residential energy retrofitters often hear much hype about new products designed to increased the efficiency of domestic water heating. This article examines how much energy these devices really save and how they save it. Topics covered include the following: nonelectronic flue dampers; recovering heat from wastewater; water that`s neither hear not there, the demand pump which improves continuous recirculation of water; cost savings. 1 fig.

TWO-PHASE (GAS-LIQUID) SYSTEM: HEAT TRANSFER AND HYDRAULICS. An Annotated Bibliography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kepple, R.R.; Tung, T.V.

1963-07-01

A bibliography of 2843 references in abstracted form is presented which covers the period l950 to 1962. The references are arranged under the following headings: books and review articles, boiling, bubble, condensation, evaporation, equations of state, interfacial characteristics, mass transfer across phase boundaries, measurement techniques, nuclear reactor heat removal, and twophase flow. An author index is included. (D.L.C.)

Spectral tuning of near-field radiative heat transfer by graphene-covered metasurfaces

NASA Astrophysics Data System (ADS)

Zheng, Zhiheng; Wang, Ao; Xuan, Yimin

2018-03-01

When two gratings are respectively covered by a layer of graphene sheet, the near-field radiative heat transfer between two parallel gratings made of silica (SiO2) could be greatly improved. As the material properties of doped silicon (n-type doping concentration is 1020 cm-3, marked as Si-20) and SiO2 differ greatly, we theoretically investigate the near-field radiative heat transfer between two parallel graphene-covered gratings made of Si-20 to explore some different phenomena, especially for modulating the spectral properties. The radiative heat flux between two parallel bulks made of Si-20 can be enhanced by using gratings instead of bulks. When the two gratings are respectively covered by a layer of graphene sheet, the radiative heat flux between two gratings made of Si-20 can be further enhanced. By tuning graphene chemical potential μ and grating filling factor f, due to the interaction between surface plasmon polaritons (SPPs) of graphene sheets and grating structures, the spectral properties of the radiative heat flux between two parallel graphene-covered gratings can be effectively regulated. This work will develop and supplement the effects of materials on the near-field radiative heat transfer for this kind of system configuration, paving a way to modulate the spectral properties of near-field radiative heat transfer.

The effect of coverings, including plastic bags and wraps, on mortality and morbidity in preterm and full-term neonates.

PubMed

Oatley, H K; Blencowe, H; Lawn, J E

2016-05-01

Neonatal hypothermia is an important risk factor for mortality and morbidity, and is common even in temperate climates. We conducted a systematic review to determine whether plastic coverings, used immediately following delivery, were effective in reducing the incidence of mortality, hypothermia and morbidity. A total of 26 studies (2271 preterm and 1003 term neonates) were included. Meta-analyses were conducted as appropriate. Plastic wraps were associated with a reduction in hypothermia in preterm (⩽29 weeks; risk ratio (RR)=0.57; 95% confidence interval (CI) 0.46 to 0.71) and term neonates (RR=0.76; 95% CI 0.60 to 0.96). No significant reduction in neonatal mortality or morbidity was found; however, the studies were underpowered for these outcomes. For neonates, especially preterm, plastic wraps combined with other environmental heat sources are effective in reducing hypothermia during stabilization and transfer within hospital. Further research is needed to quantify the effects on mortality or morbidity, and investigate the use of plastic coverings outside hospital settings or without additional heat sources.

The effect of coverings, including plastic bags and wraps, on mortality and morbidity in preterm and full-term neonates

PubMed Central

Oatley, H K; Blencowe, H; Lawn, J E

2016-01-01

Neonatal hypothermia is an important risk factor for mortality and morbidity, and is common even in temperate climates. We conducted a systematic review to determine whether plastic coverings, used immediately following delivery, were effective in reducing the incidence of mortality, hypothermia and morbidity. A total of 26 studies (2271 preterm and 1003 term neonates) were included. Meta-analyses were conducted as appropriate. Plastic wraps were associated with a reduction in hypothermia in preterm (⩽29 weeks; risk ratio (RR)=0.57; 95% confidence interval (CI) 0.46 to 0.71) and term neonates (RR=0.76; 95% CI 0.60 to 0.96). No significant reduction in neonatal mortality or morbidity was found; however, the studies were underpowered for these outcomes. For neonates, especially preterm, plastic wraps combined with other environmental heat sources are effective in reducing hypothermia during stabilization and transfer within hospital. Further research is needed to quantify the effects on mortality or morbidity, and investigate the use of plastic coverings outside hospital settings or without additional heat sources. PMID:27109095

Heat-Pipe Development for Advanced Energy Transport Concepts Final Report Covering the Period January 1999 through September 2001

DOE Office of Scientific and Technical Information (OSTI.GOV)

R.S.Reid; J.F.Sena; A.L.Martinez

2002-10-01

This report summarizes work in the Heat-pipe Technology Development for the Advanced Energy Transport Concepts program for the period January 1999 through September 2001. A gas-loaded molybdenum-sodium heat pipe was built to demonstrate the active pressure-control principle applied to a refractory metal heat pipe. Other work during the period included the development of processing procedures for and fabrication and testing of three types of sodium heat pipes using Haynes 230, MA 754, and MA 956 wall materials to assess the compatibility of these materials with sodium. Also during this period, tests were executed to measure the response of a sodiummore » heat pipe to the penetration of water.« less

Nanofluids and a method of making nanofluids for ground source heat pumps and other applications

DOEpatents

Olson, John Melvin

2013-11-12

This invention covers nanofluids. Nanofluids are a combination of particles between 1 and 100 nanometers, a surfactant and the base fluid. The nanoparticles for this invention are either pyrogenic nanoparticles or carbon nanotubes. These nanofluids improve the heat transfer of the base fluids. The base fluid can be ethylene glycol, or propylene glycol, or an aliphatic-hydrocarbon based heat transfer fluid. This invention also includes a method of making nanofluids. No surfactant is used to suspend the pyrogenic nanoparticles in glycols.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

Solar heating and hot water system installed at Municipal Building complex, Abbeville, South Carolina

NASA Technical Reports Server (NTRS)

1979-01-01

Information on the solar energy system installed at the new municipal building for the City of Abbeville, SC is presented, including a description of solar energy system and buildings, lessons learned, and recommendations. The solar space heating system is a direct air heating system. The flat roof collector panel was sized to provide 75% of the heating requirement based on an average day in January. The collectors used are job-built with two layers of filon corrugated fiberglass FRP panels cross lapped make up the cover. The storage consists of a pit filled with washed 3/4 in - 1 1/2 in diameter crushed granite stone. The air handler includes the air handling mechanism, motorized dampers, air circulating blower, sensors, control relays and mode control unit. Solar heating of water is provided only those times when the hot air in the collector is exhausted to the outside.

49 CFR 176.210 - On deck stowage requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... heat, including the direct rays of the sun, by structural erections or awnings. A tarpaulin covering the cylinders is not acceptable if it comes in contact with them. [Amdt. 176-30, 55 FR 52704, Dec. 21...

Heat pipe heat rejection system and demonstration model for the nuclear electric propulsion (NEP) spacecraft

NASA Technical Reports Server (NTRS)

Ernst, D. M.

1981-01-01

The critical evaluation and subsequent redesign of the power conversion subsystem of the spacecraft are covered. As part of that evaluation and redesign, prototype heat pipe components for the heat rejection system were designed fabricated and tested. Based on the results of these tests in conjunction with changing mission requirements and changing energy conversion devices, new system designs were investigated. The initial evaluation and redesign was based on state-of-the-art fabrication and assembly techniques for high temperature liquid metal heat pipes and energy conversion devices. The hardware evaluation demonstrated the validity of several complicated heat pipe geometries and wick structures, including an annular-to-circular transition, bends in the heat pipe, long heat pipe condensers and arterial wicks. Additionally, a heat pipe computer model was developed which describes the end point temperature profile of long radiator heat pipes to within several degrees celsius.

Heat Transfer and Fluid Mechanics Institute, Meeting, 25th, University of California, Davis, Calif., June 21-23, 1976, Proceedings

NASA Technical Reports Server (NTRS)

Mckillop, A. A.; Baughn, J. W.; Dwyer, H. A.

1976-01-01

Major research advances in heat transfer and fluid dynamics are outlined, with particular reference to relevant energy problems. Of significant importance are such topics as synthetic fuels in combustion, turbulence models, combustion modeling, numerical methods for interacting boundary layers, and light-scattering diagnostics for gases. The discussion covers thermal convection, two-phase flow and boiling heat transfer, turbulent flows, combustion, and aerospace heat transfer problems. Other areas discussed include compressible flows, fluid mechanics and drag, and heat exchangers. Featured topics comprise heat and salt transfer in double-diffusive systems, limits of boiling heat transfer in a liquid-filled enclosure, investigation of buoyancy-induced flow stratification in a cylindrical plenum, and digital algorithms for dynamic analysis of a heat exchanger. Individual items are announced in this issue.

Enhanced heat transfer surface for cast-in-bump-covered cooling surfaces and methods of enhancing heat transfer

DOEpatents

Chiu, Rong-Shi Paul; Hasz, Wayne Charles; Johnson, Robert Alan; Lee, Ching-Pang; Abuaf, Nesim

2002-01-01

An annular turbine shroud separates a hot gas path from a cooling plenum containing a cooling medium. Bumps are cast in the surface on the cooling side of the shroud. A surface coating overlies the cooling side surface of the shroud, including the bumps, and contains cooling enhancement material. The surface area ratio of the cooling side of the shroud with the bumps and coating is in excess of a surface area ratio of the cooling side surface with bumps without the coating to afford increased heat transfer across the element relative to the heat transfer across the element without the coating.

Near-field radiative heat transfer between graphene-covered hyperbolic metamaterials

NASA Astrophysics Data System (ADS)

Hong, Xiao-Juan; Li, Jian-Wen; Wang, Tong-Biao; Zhang, De-Jian; Liu, Wen-Xing; Liao, Qing-Hua; Yu, Tian-Bao; Liu, Nian-Hua

2018-04-01

We propose the use of graphene-covered silicon carbide (SiC) nanowire arrays (NWAs) for theoretical studies of near-field radiative heat transfer. The SiC NWAs exhibit a hyperbolic characteristic at an appropriately selected filling-volume fraction. The surface plasmon supported by graphene and the hyperbolic modes supported by SiC NWAs significantly affect radiative heat transfer. The heat-transfer coefficient (HTC) between the proposed structures is larger than that between SiC NWAs. We also find that the chemical potential of graphene plays an important role in modulating the HTC. The tunability of chemical potential through gate voltage enables flexible control of heat transfer using the graphene-covered SiC NWAs.

Proceedings of the First National Workshop on the Global Weather Experiment: Current Achievements and Future Directions, volume 2, part 1

NASA Technical Reports Server (NTRS)

1985-01-01

Topics covered include: data systems and quality; analysis and assimilation techniques; impacts on forecasts; tropical forecasts; analysis intercomparisons; improvements in predictability; and heat sources and sinks.

Sludge Conditioning. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

ERIC Educational Resources Information Center

Carnegie, John W.

This lesson is an introduction to sludge conditioning. Topics covered include a brief explanation of colloidal systems, theory of chemical and heat conditioning, and conditioning aids. The lesson includes an instructor's guide and student workbook. The instructor's guide contains a description of the lesson, estimated presentation time,…

APPARATUS FOR CONVERTING HEAT INTO ELECTRICITY

DOEpatents

Crouthamel, C.E.; Foster, M.S.

1964-01-28

This patent shows an apparatus for converting heat to electricity. It includes a galvanic cell having an anodic metal anode, a fused salt electrolyte, and a hydrogen cathode having a diffusible metal barrier of silver-- palladium alloy covered with sputtered iron on the side next to the fused electrolyte. Also shown is a regenerator for regenerating metal hydride produced by the galvanic cell into hydrogen gas and anodic metal, both of which are recycled. (AEC)

Dish/stirling hybrid-receiver

DOEpatents

Mehos, Mark S.; Anselmo, Kenneth M.; Moreno, James B.; Andraka, Charles E.; Rawlinson, K. Scott; Corey, John; Bohn, Mark S.

2002-01-01

A hybrid high-temperature solar receiver is provided which comprises a solar heat-pipe-receiver including a front dome having a solar absorber surface for receiving concentrated solar energy, a heat pipe wick, a rear dome, a sidewall joining the front and the rear dome, and a vapor and a return liquid tube connecting to an engine, and a fossil fuel fired combustion system in radial integration with the sidewall for simultaneous operation with the solar heat pipe receiver, the combustion system comprising an air and fuel pre-mixer, an outer cooling jacket for tangentially introducing and cooling the mixture, a recuperator for preheating the mixture, a burner plenum having an inner and an outer wall, a porous cylindrical metal matrix burner firing radially inward facing a sodium vapor sink, the mixture ignited downstream of the matrix forming combustion products, an exhaust plenum, a fossil-fuel heat-input surface having an outer surface covered with a pin-fin array, the combustion products flowing through the array to give up additional heat to the receiver, and an inner surface covered with an extension of the heat-pipe wick, a pin-fin shroud sealed to the burner and exhaust plenums, an end seal, a flue-gas diversion tube and a flue-gas valve for use at off-design conditions to limit the temperature of the pre-heated air and fuel mixture, preventing pre-ignition.

Architecture for Absorption Based Heaters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moghaddam, Saeed; Chugh, Devesh

An absorption based heater is constructed on a fluid barrier heat exchanging plate such that it requires little space in a structure. The absorption based heater has a desorber, heat exchanger, and absorber sequentially placed on the fluid barrier heat exchanging plate. The vapor exchange faces of the desorber and the absorber are covered by a vapor permeable membrane that is permeable to a refrigerant vapor but impermeable to an absorbent. A process fluid flows on the side of the fluid barrier heat exchanging plate opposite the vapor exchange face through the absorber and subsequently through the heat exchanger. Themore » absorption based heater can include a second plate with a condenser situated parallel to the fluid barrier heat exchanging plate and opposing the desorber for condensation of the refrigerant for additional heating of the process fluid.« less

40 CFR 763.163 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... asbestos-containing product which is made of paper intended for use as general insulation paper or muffler paper. Major applications of commercial papers are insulation against fire, heat transfer, and corrosion... include: thermal insulation for pipe coverings; block insulation; panel insulation in elevators...

40 CFR 763.163 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... asbestos-containing product which is made of paper intended for use as general insulation paper or muffler paper. Major applications of commercial papers are insulation against fire, heat transfer, and corrosion... include: thermal insulation for pipe coverings; block insulation; panel insulation in elevators...

40 CFR 763.163 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... asbestos-containing product which is made of paper intended for use as general insulation paper or muffler paper. Major applications of commercial papers are insulation against fire, heat transfer, and corrosion... include: thermal insulation for pipe coverings; block insulation; panel insulation in elevators...

40 CFR 763.163 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... asbestos-containing product which is made of paper intended for use as general insulation paper or muffler paper. Major applications of commercial papers are insulation against fire, heat transfer, and corrosion... include: thermal insulation for pipe coverings; block insulation; panel insulation in elevators...

40 CFR 763.163 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... asbestos-containing product which is made of paper intended for use as general insulation paper or muffler paper. Major applications of commercial papers are insulation against fire, heat transfer, and corrosion... include: thermal insulation for pipe coverings; block insulation; panel insulation in elevators...

Evolution of Space Station EMU PLSS technology recommendations

NASA Technical Reports Server (NTRS)

Wilde, Richard C.

1990-01-01

Viewgraphs on extravehicular mobility unit (EMU) portable life support system (PLSS) technology recommendations are presented. Topics covered include: oxygen supply storage; oxygen supply regulators; carbon dioxide control; prime movers; crew comfort; heat rejection; power sources; controls; display devices; and sensor technology.

Active control of near-field radiative heat transfer between graphene-covered metamaterials

NASA Astrophysics Data System (ADS)

Zhao, Qimei; Zhou, Ting; Wang, Tongbiao; Liu, Wenxing; Liu, Jiangtao; Yu, Tianbao; Liao, Qinghua; Liu, Nianhua

2017-04-01

In this study, the near-field radiative heat transfer between graphene-covered metamaterials is investigated. The electric surface plasmons (SPs) supported by metamaterials can be coupled with the SPs supported by graphene. The near-field heat transfer between the graphene-covered metamaterials is significantly larger than that between metamaterials because of the strong coupling in our studied frequency range. The relationship between heat flux and chemical potential is studied for different vacuum gaps. Given that the chemical potential of graphene can be tuned by the external electric field, heat transfer can be actively controlled by modulating the chemical potential. The heat flux for certain vacuum gaps can reach a maximum value when the chemical potential is at a particular value. The results of this study are beneficial for actively controlling energy transfer.

Casting methods

DOEpatents

Marsden, Kenneth C.; Meyer, Mitchell K.; Grover, Blair K.; Fielding, Randall S.; Wolfensberger, Billy W.

2012-12-18

A casting device includes a covered crucible having a top opening and a bottom orifice, a lid covering the top opening, a stopper rod sealing the bottom orifice, and a reusable mold having at least one chamber, a top end of the chamber being open to and positioned below the bottom orifice and a vacuum tap into the chamber being below the top end of the chamber. A casting method includes charging a crucible with a solid material and covering the crucible, heating the crucible, melting the material, evacuating a chamber of a mold to less than 1 atm absolute through a vacuum tap into the chamber, draining the melted material into the evacuated chamber, solidifying the material in the chamber, and removing the solidified material from the chamber without damaging the chamber.

Spatial Analysis of Post-Hurricane Katrina Thermal Pattern and Intensity in Greater New Orleans: Implications for Urban Heat Island Phenomenon

NASA Astrophysics Data System (ADS)

Lief, Aram Parrish

In 2005, Hurricane Katrina's diverse impacts on the Greater New Orleans area included damaged and destroyed trees, and other despoiled vegetation, which also increased the exposure of artificial and bare surfaces, known factors that contribute to the climatic phenomenon known as the urban heat island (UHI). This is an investigation of UHI in the aftermath of Hurricane Katrina, which entails the analysis of pre and post-hurricane Katrina thermal imagery of the study area, including changes to surface heat patterns and vegetative cover. Imagery from Landsat TM was used to show changes to the pattern and intensity of the UHI effect, caused by an extreme weather event. Using remote sensing visualization methods, in situ data, and local knowledge, the author found there was a measurable change in the pattern and intensity of the New Orleans UHI effect, as well as concomitant changes to vegetative land cover. This finding may be relevant for urban planners and citizens, especially in the context of recovery from a large-scale disaster of a coastal city, regarding future weather events, and other natural and human impacts.

INTERCOMPARISON OF ALTERNATIVE VEGETATION DATABASES FOR REGIONAL AIR QUALITY MODELING

EPA Science Inventory

Vegetation cover data are used to characterize several regional air quality modeling processes, including the calculation of heat, moisture, and momentum fluxes with the Mesoscale Meteorological Model (MM5) and the estimate of biogenic volatile organic compound and nitric oxide...

Projected changes in atmospheric heating due to changes in fire disturbance and the snow season in the western Arctic, 2003–2100

USGS Publications Warehouse

Euskirchen, E.S.; McGuire, A. David; Rupp, T.S.; Chapin, F. S.; Walsh, J.E.

2009-01-01

In high latitudes, changes in climate impact fire regimes and snow cover duration, altering the surface albedo and the heating of the regional atmosphere. In the western Arctic, under four scenarios of future climate change and future fire regimes (2003–2100), we examined changes in surface albedo and the related changes in regional atmospheric heating due to: (1) vegetation changes following a changing fire regime, and (2) changes in snow cover duration. We used a spatially explicit dynamic vegetation model (Alaskan Frame-based Ecosystem Code) to simulate changes in successional dynamics associated with fire under the future climate scenarios, and the Terrestrial Ecosystem Model to simulate changes in snow cover. Changes in summer heating due to the changes in the forest stand age distributions under future fire regimes showed a slight cooling effect due to increases in summer albedo (mean across climates of −0.9 W m−2 decade−1). Over this same time period, decreases in snow cover (mean reduction in the snow season of 4.5 d decade−1) caused a reduction in albedo, and a heating effect (mean across climates of 4.3 W m−2 decade−1). Adding both the summer negative change in atmospheric heating due to changes in fire regimes to the positive changes in atmospheric heating due to changes in the length of the snow season resulted in a 3.4 W m−2 decade−1 increase in atmospheric heating. These findings highlight the importance of gaining a better understanding of the influences of changes in surface albedo on atmospheric heating due to both changes in the fire regime and changes in snow cover duration.

Urban effects on regional climate: a case study in the Phoenix and Tucson ‘sun’ corridor

USGS Publications Warehouse

Zhao Yang,; Francina Dominguez,; Hoshin Gupta,; Xubin Zeng,; Norman, Laura M.

2016-01-01

Land use and land cover change (LULCC) due to urban expansion alter the surface albedo, heat capacity, and thermal conductivity of the surface. Consequently, the energy balance in urban regions is different from that of natural surfaces. To evaluate the changes in regional climate that could arise due to projected urbanization in the Phoenix-Tucson corridor, Arizona, we applied the coupled WRF-NOAH-UCM (which includes a detailed urban radiation scheme) to this region. Land cover changes were represented using land cover data for 2005 and projections to 2050, and historical North American Regional Reanalysis (NARR) data were used to specify the lateral boundary conditions. Results suggest that temperature changes will be well defined, reflecting the urban heat island (UHI) effect within areas experiencing LULCC. Changes in precipitation are less robust, but seem to indicate reductions in precipitation over the mountainous regions northeast of Phoenix and decreased evening precipitation over the newly-urbanized area.

Satellite Studies of Cirrus Clouds for Project Fire

NASA Technical Reports Server (NTRS)

1997-01-01

Examine global cloud climatologies for evidence of human caused changes in cloud cover and their effect on the Earth's heat budget through radiative processes. Quantify climatological changes in global cloud cover and estimate their effect on the Earth's heat budget. Improve our knowledge of global cloud cover and its changes through the merging of several satellite data sets.

Pyrolytic graphite gauge for measuring heat flux

NASA Technical Reports Server (NTRS)

Bunker, Robert C. (Inventor); Ewing, Mark E. (Inventor); Shipley, John L. (Inventor)

2002-01-01

A gauge for measuring heat flux, especially heat flux encountered in a high temperature environment, is provided. The gauge includes at least one thermocouple and an anisotropic pyrolytic graphite body that covers at least part of, and optionally encases the thermocouple. Heat flux is incident on the anisotropic pyrolytic graphite body by arranging the gauge so that the gauge surface on which convective and radiative fluxes are incident is perpendicular to the basal planes of the pyrolytic graphite. The conductivity of the pyrolytic graphite permits energy, transferred into the pyrolytic graphite body in the form of heat flux on the incident (or facing) surface, to be quickly distributed through the entire pyrolytic graphite body, resulting in small substantially instantaneous temperature gradients. Temperature changes to the body can thereby be measured by the thermocouple, and reduced to quantify the heat flux incident to the body.

Tear-Film Evaporation Rate from Simultaneous Ocular-Surface Temperature and Tear-Breakup Area.

PubMed

Dursch, Thomas J; Li, Wing; Taraz, Baseem; Lin, Meng C; Radke, Clayton J

2018-01-01

A corneal heat-transfer model is presented to quantify simultaneous measurements of fluorescein tear-breakup area (TBA) and ocular-surface temperature (OST). By accounting for disruption of the tear-film lipid layer (TFLL), we report evaporation rates through lipid-covered tear. The modified heat-transfer model provides new insights into evaporative dry eye. A quantitative analysis is presented to assess human aqueous tear evaporation rate (TER) through intact TFLLs from simultaneous in vivo measurement of time-dependent infrared OST and fluorescein TBA. We interpret simultaneous OST and TBA measurements using an extended heat-transfer model. We hypothesize that TBAs are ineffectively insulated by the TFLL and therefore exhibit higher TER than does that for a well-insulting TFLL-covered tear. As time proceeds, TBAs increase in number and size, thereby increasing the cornea area-averaged TER and decreasing OST. Tear-breakup areas were assessed from image analysis of fluorescein tear-film-breakup video recordings and are included in the heat-transfer description of OST. Model-predicted OSTs agree well with clinical experiments. Percent reductions in TER of lipid-covered tear range from 50 to 95% of that for pure water, in good agreement with literature. The physical picture of noninsulating or ruptured TFLL spots followed by enhanced evaporation from underlying cooler tear-film ruptures is consistent with the evaporative-driven mechanism for local tear rupture. A quantitative analysis is presented of in vivo TER from simultaneous clinical measurement of transient OST and TBA. The new heat-transfer model accounts for increased TER through expanding TBAs. Tear evaporation rate varies strongly across the cornea because lipid is effectively missing over tear-rupture troughs. The result is local faster evaporation compared with nonruptured, thick lipid-covered tear. Evaporative-driven tear-film ruptures deepen to a thickness where fluorescein quenching commences and local salinity rises to uncomfortable levels. Mitigation of tear-film rupture may therefore reduce dry eye-related symptoms.

Land Use and Land Cover Change, Urban Heat Island Phenomenon, and Health Implications: A Remote Sensing Approach

NASA Technical Reports Server (NTRS)

Lo, C. P.; Quattrochi, Dale A.

2003-01-01

Land use and land cover maps of Atlanta Metropolitan Area in Georgia were produced from Landsat MSS and TM images for 1973,1979,1983,1987,1992, and 1997, spanning a period of 25 years. Dramatic changes in land use and land cover have occurred with loss of forest and cropland to urban use. In particular, low-density urban use, which includes largely residential use, has increased by over 119% between 1973 and 1997. These land use and land cover changes have drastically altered the land surface characteristics. An analysis of Landsat images revealed an increase in surface temperature and a decline in NDVI from 1973 to 1997. These changes have forced the development of a significant urban heat island effect and an increase in ground level ozone production to such an extent, that Atlanta has violated EPA's ozone level standard in recent years. The urban heat island initiated precipitation events that were identified between 1996 and 2000 tended to occur near high-density urban areas but outside the I-285 loop that traverses around the Central Business District, i.e. not in the inner city area, but some in close proximity to the highways. The health implications were investigated by comparing the spatial patterns of volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions, the two ingredients that form ozone by reacting with sunlight, with those of rates of cardiovascular and chronic lower respiratory diseases. A clear core-periphery pattern was revealed for both VOC and NOx emissions, but the spatial pattern was more random in the cases of rates of cardiovascular and chronic lower respiratory diseases. Clearly, factors other than ozone pollution were involved in explaining the rates of these diseases. Further research is therefore needed to understand the health geography and its relationship to land use and land cover change as well as urban heat island effect. This paper illustrates the usefulness of a remote sensing approach for this purpose.

Cutaneous Heat Loss with Three Surgical Drapes, One Impervious to Moisture

PubMed Central

Maglinger, Paul E.; Sessler, Daniel I.; Lenhardt, Rainer

2005-01-01

A new surgical drape, which is impervious to moisture, presumably reduces evaporative heat loss. We compared cutaneous heat loss and skin temperature in volunteers covered with this drape to two conventional surgical drapes (Large Surgical Drape and Medline Proxima). With IRB approval and informed consent, we calculated cutaneous heat loss and skin-surface temperatures from 15 area-weighted thermal flux transducers in 8 volunteers. In random order, each of the drapes was evaluated with dry transducers and moistened transducers (simulating wet skin). After a 20-minute uncovered control period, volunteers were covered from the neck down for 40 minutes. Data were recorded continuously and averaged over 10-minutes. Results were similar for all three drapes for dry or moist conditions. Under dry conditions, baseline heat loss was 82±14 watts (W) and decreased 30% with a surgical drape (P<0.001). Under moist conditions, baseline heat loss was 231±45 W and decreased 29% with a drape covering (P<0.001). Moist skin increased heat loss 282% (P<0.001). There were no clinically important differences in skin temperature among the covers with dry or moist skin. Moist skin increased heat loss nearly three-fold, but there were no differences among the drapes. We conclude that loss is comparable with impervious and conventional drapes with either moist or dry skin. PMID:15728062

Investigation of lunar base thermal control system options

NASA Technical Reports Server (NTRS)

Ewart, Michael K.

1993-01-01

Long duration human exploration missions to the Moon will require active thermal control systems which have not previously been used in space. The two technologies which are most promising for long term lunar base thermal control are heat pumps and radiator shades. Recent trade-off studies at the Johnson Space Center have focused development efforts on the most promising heat pump and radiator shade technologies. Since these technologies are in the early stages of development and many parameters used in the study are not well defined, a parametric study was done to test the sensitivity to each assumption. The primary comparison factor in these studies was the total mass system, with power requirements included in the form of a mass penalty for power. Heat pump technologies considered were thermally driven heat pumps such as metal hydride, complex compound, absorption and zeolite. Also considered were electrically driven Stirling and vapor compression heat pumps. Radiator shade concepts considered included step shaped, V-shaped and parabolic (or catenary) shades and ground covers. A further trade study compared the masses of heat pump and radiator shade systems.

Dual nozzle aerodynamic and cooling analysis study. [dual throat and dual expander nozzles

NASA Technical Reports Server (NTRS)

Meagher, G. M.

1980-01-01

Geometric, aerodynamic flow field, performance prediction, and heat transfer analyses are considered for two advanced chamber nozzle concepts applicable to Earth-to-orbit engine systems. Topics covered include improvements to the dual throat aerodynamic and performance prediction program; geometric and flow field analyses of the dual expander concept; heat transfer analysis of both concepts, and engineering analysis of data from the NASA/MSFC hot-fire testing of a dual throat thruster model thrust chamber assembly. Preliminary results obtained are presented in graphs.

University role in astronaut life support systems: Portable thermal control systems

NASA Technical Reports Server (NTRS)

Ephrath, A. R.

1971-01-01

One of the most vital life support systems is that used to provide the astronaut with an adequate thermal environment. State-of-the-art techniques are reviewed for collecting and rejecting excess heat loads from the suited astronaut. Emphasis is placed on problem areas which exist and which may be suitable topics for university research. Areas covered include thermal control requirements and restrictions, methods of heat absorption and rejection or storage, and comparison between existing methods and possible future techniques.

Power control for heat engines

DOEpatents

Dineen, John J.

1984-01-01

A power control arrangement for a Stirling engine includes a sleeve mounted in each cylinder for axial movement and a port in the sleeve leading to a dead space. The port is covered by the piston at a position that is determined by the piston position and the axial adjustment of the sleeve. The compression phase of the Stirling cycle for that piston begins when the port is covered, so the position of the sleeve is used to set the Stirling engine power level.

Development of Active Microwave Thermography for Structural Health Monitoring

NASA Astrophysics Data System (ADS)

Foudazi, Ali

Active Microwave Thermography (AMT) is an integrated nondestructive testing and evaluation (NDT&E) method that incorporates aspects of microwave NDT and thermography techniques. AMT uses a microwave excitation to generate heat and the surface thermal profile of the material or structure under test is subsequently measured using a thermal camera (or IR camera). Utilizing a microwave heat excitation provides advantages over traditional thermal excitations (heat lamps, etc.) including the potential for non-contact, selective and focused heating. During an AMT inspection, two heating mechanisms are possible, referred to as dielectric and induction heating. Dielectric heating occurs as a result of the interaction of microwave energy with lossy dielectric materials which results in dissipated microwave energy and a subsequent increase in temperature. Induction heating is a result of induced surface current on conductive materials with finite conductivity under microwave illumination and subsequently ohmic loss. Due to the unique properties of microwave signals including frequency of operation, power level, and polarization, as well as their interaction with different materials, AMT has strong potential for application in various industries including infrastructure, transportation, aerospace, etc. As such, this Dissertation explores the application of AMT to NDT&E needs in these important industries, including detection and evaluation of defects in single- or multi-layered fiber-reinforced polymer-strengthened cement-based materials, evaluation of steel fiber percentage and distributions in steel fiber reinforced structures, characterization of corrosion ratio on corroded reinforcing steel bars (rebar), and evaluation of covered surface cracks orientation and size in metal structures.

Biology Today: Of Wishbones, Beavers & Blinking.

ERIC Educational Resources Information Center

Flannery, Maura, Ed.

1989-01-01

Provided is a discussion of items covering a variety of fascinating biological topics which include: the elasticity of the furcula of starlings in flight, beavers increasing the greenhouse effect, effective invaders, traveling birds, the cuckoo deception, competitive sperm, hearing springs, heat and sight, blinking as punctuation, mutations, and…

Energy Management Checklist for the Home.

ERIC Educational Resources Information Center

Pifer, Glenda

This booklet contains a checklist of equipment and activities for the individual's use in home energy management. The categories covered include: (1) insulation; (2) windows; (3) temperature control; (4) lighting; (5) heating water; (6) laundry; (7) cleaning and maintenance; (8) cooking; (9) refrigeration; (10) dishwashing; (11) recreation; and…

76 FR 15802 - Airworthiness Directives; Eurocopter France (Eurocopter) Model EC130 B4 Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-22

... in insert D of Figure 5 of the EASB, and determine if it is covered with heat shrink, P/N... shown in insert D of Figure 5 or the attachment screw is not covered with heat shrink, modify the.... Figure 5 of the EASB does not show the heat shrink installed for clarity of screw head and lug detail. (3...

Carbon dioxide and energy fluxes over a large shallow lake in China

NASA Astrophysics Data System (ADS)

Zhao, Xiaosong

2017-04-01

The turbulent exchange of carbon dioxide and energy between water and atmosphere over lakes differ from those over vegetated surfaces due to high heat capacity of water and different water ecological environment. For a shallow lake, the underlying surface generally changes between water covered and land covered with water level fluctuation, which significantly influences carbon dioxide and energy fluxes. Continuous measurement of the carbon dioxide (CO2), latent (LE) and sensible (H) heat fluxes was made using the eddy covariance method over the Poyang Lake, the largest fresh lake in China, from August 2013 to December 2015. Results indicated that the surface energy budget has a strong seasonal pattern, with peaks in LE and H observed in early August and September. There was 10 days delay between the net radiation and the latent heat flux. More net radiation (Rn) was allocated to the LE rather than H through the year, with monthly mean LE/Rn of 0.65 and H/Rn of 0.11, which caused Bowen ratio was 0.15 in water-covered period, lower than that in land-covered period. The water heat storage experienced shifting from heat storage to heat release, with maximum heat storage in July and maximum heat release in September. The water heat advection was account for 4% to 10% of Rn and peaked in June. The annual evaporation is 875 mm, 893 mm and 1019 mm in 2013 (from August 2013 to July 2014), 2014 and 2015, which was account for approximately 57% of precipitation in the three years. The large lake acted as a CO2 source in inundating period and a CO2 sink in exposure period. The energy fluxes were controlled by environmental factors with timescale dependence. On daily scale, the LE and H were highly correlated with product of wind speed and vapor pressure deficit (UVPD) or wind speed (U) in the water-covered period, and with Rn in the land-covered period. Monthly LE, H and annual H were controlled by Rn, while annual LE was primarily dependent on water depth. Annual CO2 budget was regulated by duration of inundating period.

Improving urban district heating systems and assessing the efficiency of the energy usage therein

NASA Astrophysics Data System (ADS)

Orlov, M. E.; Sharapov, V. I.

2017-11-01

The report describes issues in connection with improving urban district heating systems from combined heat power plants (CHPs), to propose the ways for improving the reliability and the efficiency of the energy usage (often referred to as “energy efficiency”) in such systems. The main direction of such urban district heating systems improvement suggests transition to combined heating systems that include structural elements of both centralized and decentralized systems. Such systems provide the basic part of thermal power via highly efficient methods for extracting thermal power plants turbines steam, while peak loads are covered by decentralized peak thermal power sources to be mounted at consumers’ locations, with the peak sources being also reserve thermal power sources. The methodology was developed for assessing energy efficiency of the combined district heating systems, implemented as a computer software product capable of comparatively calculating saving on reference fuel for the system.

Optimization of the functional domain of flat plate collectors

NASA Astrophysics Data System (ADS)

Ritoux, G.; Irigaray, J.-L.

1981-12-01

The variations of the extracted heat flux as function of the temperature of the heat transfer fluid in black and selective surface solar collectors are examined. The heat flux is calculated based on the difference of the initial to the stage of thermal equilibrium of the fluid. A nonlinear system of equations is developed and solved by a fast, iterative method to obtain the equilibrium temperatures. It is found that more flux can be extracted from the solar heat by a collector with only one glass cover than with more than one cover. The captured flux is proportional to the coefficient of transmission of the glass coverings, to the coefficient of absorption of the collector, and to the incident flux. Black painted surfaces were more absorbent than selective surfaces, and highest collection efficiencies were displayed by low temperature collectors. Charts of effective uses of the respective types of collectors for heating swimming pools, hot water, home heat, and for refrigeration and air-conditioning are provided.

Numerical Investigation of the Thermal Regime of Underground Channel Heat Pipelines Under Flooding Conditions with the Use of a Conductive-Convective Heat Transfer Model

NASA Astrophysics Data System (ADS)

Polovnikov, V. Yu.

2018-05-01

This paper presents the results of numerical analysis of thermal regimes and heat losses of underground channel heating systems under flooding conditions with the use of a convective-conductive heat transfer model with the example of the configuration of the heat pipeline widely used in the Russian Federation — a nonpassage ferroconcrete channel (crawlway) and pipelines insulated with mineral wool and a protective covering layer. It has been shown that convective motion of water in the channel cavity of the heat pipeline under flooding conditions has no marked effect on the intensification of heat losses. It has been established that for the case under consideration, heat losses of the heat pipeline under flooding conditions increase from 0.75 to 52.39% due to the sharp increase in the effective thermal characteristics of the covering layer and the heat insulator caused by their moistening.

Numerical Investigation of the Thermal Regime of Underground Channel Heat Pipelines Under Flooding Conditions with the Use of a Conductive-Convective Heat Transfer Model

NASA Astrophysics Data System (ADS)

Polovnikov, V. Yu.

2018-03-01

This paper presents the results of numerical analysis of thermal regimes and heat losses of underground channel heating systems under flooding conditions with the use of a convective-conductive heat transfer model with the example of the configuration of the heat pipeline widely used in the Russian Federation — a nonpassage ferroconcrete channel (crawlway) and pipelines insulated with mineral wool and a protective covering layer. It has been shown that convective motion of water in the channel cavity of the heat pipeline under flooding conditions has no marked effect on the intensification of heat losses. It has been established that for the case under consideration, heat losses of the heat pipeline under flooding conditions increase from 0.75 to 52.39% due to the sharp increase in the effective thermal characteristics of the covering layer and the heat insulator caused by their moistening.

An Integrated Approach to Thermodynamics in the Introductory Physics Course.

ERIC Educational Resources Information Center

Alonso, Marcelo; Finn, Edward J.

1995-01-01

Presents an approach to combine the empirical approach of classical thermodynamics with the structural approach of statistical mechanics. Topics covered include dynamical foundation of the first law; mechanical work, heat, radiation, and the first law; thermal equilibrium; thermal processes; thermodynamic probability; entropy; the second law;…

Manufacture and quality control of interconnecting wire harnesses, Volume 3

NASA Technical Reports Server (NTRS)

1972-01-01

The document covers interconnecting wire harnesses defined in the design standard, including type 6, enclosed in TFE heat shrink tubing; and type 7, flexible armored. Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated into this document.

Proceedings of the First Semiannual Distributed Receiver Program Review

NASA Technical Reports Server (NTRS)

1980-01-01

Point focus and line focus distributed receiver solar thermal technology for the production of electric power and of industrial process heat is addressed. Concentrator, receiver, and power conversion development are covered along with hardware tests and evaluation. Mass production costing, parabolic dish applications, and trough and bowl systems are included.

75 Easy Physics Demonstrations. Teacher Book.

ERIC Educational Resources Information Center

Kardos, Thomas

This book is a collection of classroom demonstrations in physics designed to present basic scientific ideas on a concrete level. The topics covered include: physical change and properties of matter; energy waves and energy forms; absorption of heat; radiant energy; vacuum bottles; kinetic molecular theory; states of matter; pressure of air; work…

Nuclear Energy for Water Desalting, A Bibliography.

ERIC Educational Resources Information Center

Kuhns, Helen F., Comp.; And Others

This bibliography includes 215 abstracts of publications on the use of nuclear energy in the production of potable water from saline or brackish waters. The uses of nuclear reactors, radioisotopic heat sources, and nuclear explosives are covered in relation to the various desalination methods available. Literature through April 1967 has been…

Transparent heat-spreader for optoelectronic applications

DOEpatents

Minano, Juan Carlos; Benitez, Pablo

2014-11-04

An optoelectronic cooling system is equally applicable to an LED collimator or a photovoltaic solar concentrator. A transparent fluid conveys heat from the optoelectronic chip to a hollow cover over the system aperture. The cooling system can keep a solar concentrator chip at the same temperature as found for a one-sun flat-plate solar cell. Natural convection or forced circulation can operate to convey heat from the chip to the cover.

Thermal processes of thermokarst lakes in the continuous permafrost zone of northern Siberia - observations and modeling (Lena River Delta, Siberia)

NASA Astrophysics Data System (ADS)

Boike, J.; Georgi, C.; Kirilin, G.; Muster, S.; Abramova, K.; Fedorova, I.; Chetverova, A.; Grigoriev, M.; Bornemann, N.; Langer, M.

2015-10-01

Thermokarst lakes are typical features of the northern permafrost ecosystems, and play an important role in the thermal exchange between atmosphere and subsurface. The objective of this study is to describe the main thermal processes of the lakes and to quantify the heat exchange with the underlying sediments. The thermal regimes of five lakes located within the continuous permafrost zone of northern Siberia (Lena River Delta) were investigated using hourly water temperature and water level records covering a 3-year period (2009-2012), together with bathymetric survey data. The lakes included thermokarst lakes located on Holocene river terraces that may be connected to Lena River water during spring flooding, and a thermokarst lake located on deposits of the Pleistocene Ice Complex. Lakes were covered by ice up to 2 m thick that persisted for more than 7 months of the year, from October until about mid-June. Lake-bottom temperatures increased at the start of the ice-covered period due to upward-directed heat flux from the underlying thawed sediment. Prior to ice break-up, solar radiation effectively warmed the water beneath the ice cover and induced convective mixing. Ice break-up started at the beginning of June and lasted until the middle or end of June. Mixing occurred within the entire water column from the start of ice break-up and continued during the ice-free periods, as confirmed by the Wedderburn numbers, a quantitative measure of the balance between wind mixing and stratification that is important for describing the biogeochemical cycles of lakes. The lake thermal regime was modeled numerically using the FLake model. The model demonstrated good agreement with observations with regard to the mean lake temperature, with a good reproduction of the summer stratification during the ice-free period, but poor agreement during the ice-covered period. Modeled sensitivity to lake depth demonstrated that lakes in this climatic zone with mean depths > 5 m develop continuous stratification in summer for at least 1 month. The modeled vertical heat flux across the bottom sediment tends towards an annual mean of zero, with maximum downward fluxes of about 5 W m-2 in summer and with heat released back into the water column at a rate of less than 1 W m-2 during the ice-covered period. The lakes are shown to be efficient heat absorbers and effectively distribute the heat through mixing. Monthly bottom water temperatures during the ice-free period range up to 15 °C and are therefore higher than the associated monthly air or ground temperatures in the surrounding frozen permafrost landscape. The investigated lakes remain unfrozen at depth, with mean annual lake-bottom temperatures of between 2.7 and 4 °C.

Heatwaves and their impact on people with alcohol, drug and mental health conditions: a discussion paper on clinical practice considerations.

PubMed

Cusack, Lynette; de Crespigny, Charlotte; Athanasos, Peter

2011-04-01

This article discusses the clinical implications of adverse health outcomes derived during heatwaves for people with mental health disorders, substance misuse and those taking prescribed medications such as lithium, various neuroleptic and anticholinergic drugs. With climate change it is predicted that the incidence of prolonged periods of extreme heat will increase. Specific adverse health outcomes associated with high environmental temperatures include heat stroke and heat exhaustion. Those at increased risk for heat-related mortality are those with chronic health conditions, including those with mental health disorders and substance misuse. Sources of evidence included and 'grey' literature published between 1985 and 2010, such as key texts, empirical research, public policies, training manuals and community information sheets on heat waves. Current clinical practice and clinical impact of heatwaves on those people with comorbidity is explored. This includes the physiological components of heat stress, heat regulation, and the impact of alcohol and other drugs; and, ramifications and professional practice issues for those with mental health conditions and those requiring mental health medications. Client education covering modification of the environment and the use of client heat safety action plans. Secure, accessible stores of prescribed medication are recommended and emergency substance withdrawal kits could be made available. All nurses have a responsibility to increase the capability and resilience of their clients to manage their chronic health needs during a heatwave. At these times nurses need to give extra monitoring and assistance when clients lack the capacity or resources to protect themselves. © 2011 The Authors. Journal of Advanced Nursing © 2011 Blackwell Publishing Ltd.

Thickness of tropical ice and photosynthesis on a snowball Earth

NASA Technical Reports Server (NTRS)

McKay, C. P.

2000-01-01

On a completely ice-covered "snowball" Earth the thickness of ice in the tropical regions would be limited by the sunlight penetrating into the ice cover and by the latent heat flux generated by freezing at the ice bottom--the freezing rate would balance the sublimation rate from the top of the ice cover. Heat transfer models of the perennially ice-covered Antarctic dry valley lakes applied to the snowball Earth indicate that the tropical ice cover would have a thickness of 10 m or less with a corresponding transmissivity of > 0.1%. This light level is adequate for photosynthesis and could explain the survival of the eukaryotic algae.

Thickness of tropical ice and photosynthesis on a snowball Earth.

PubMed

McKay, C P

2000-07-15

On a completely ice-covered "snowball" Earth the thickness of ice in the tropical regions would be limited by the sunlight penetrating into the ice cover and by the latent heat flux generated by freezing at the ice bottom--the freezing rate would balance the sublimation rate from the top of the ice cover. Heat transfer models of the perennially ice-covered Antarctic dry valley lakes applied to the snowball Earth indicate that the tropical ice cover would have a thickness of 10 m or less with a corresponding transmissivity of > 0.1%. This light level is adequate for photosynthesis and could explain the survival of the eukaryotic algae.

Mathematical model of compact type evaporator

NASA Astrophysics Data System (ADS)

Borovička, Martin; Hyhlík, Tomáš

2018-06-01

In this paper, development of the mathematical model for evaporator used in heat pump circuits is covered, with focus on air dehumidification application. Main target of this ad-hoc numerical model is to simulate heat and mass transfer in evaporator for prescribed inlet conditions and different geometrical parameters. Simplified 2D mathematical model is developed in MATLAB SW. Solvers for multiple heat and mass transfer problems - plate surface temperature, condensate film temperature, local heat and mass transfer coefficients, refrigerant temperature distribution, humid air enthalpy change are included as subprocedures of this model. An automatic procedure of data transfer is developed in order to use results of MATLAB model in more complex simulation within commercial CFD code. In the end, Proper Orthogonal Decomposition (POD) method is introduced and implemented into MATLAB model.

40 CFR 63.654 - Heat exchange systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) through (g) of this section if all heat exchangers within the heat exchange system either: (1) Operate... exposure to air for each heat exchange system. (ii) Selected heat exchanger exit line(s) so that each heat exchanger or group of heat exchangers within a heat exchange system is covered by the selected monitoring...

40 CFR 63.654 - Heat exchange systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) through (g) of this section if all heat exchangers within the heat exchange system either: (1) Operate... exposure to air for each heat exchange system. (ii) Selected heat exchanger exit line(s) so that each heat exchanger or group of heat exchangers within a heat exchange system is covered by the selected monitoring...

Heat pipes in solar collectors

NASA Astrophysics Data System (ADS)

Bairamov, R.; Toiliev, K.

The diode property of heat pipes is evaluated for use in solar collectors. Model experiments show that the effect of heat pipes in solar collectors is most pronounced during the nighttime, when solar radiation is zero, due to a significant reduction in the heat loss from the transparent cover surface of the collector compared to that for conventional collectors. For a solar collector with a glass cover area of one square meter during the summer season when the maximum water temperature is 60 C and the discharge is 85 l/sq m/day, the water temperature in the accumulator tank of the solar collector with a heat pipe is 10-11 C higher than in the solar collector lacking a heat pipe. In addition, the design of a solar house with passive systems in which heat pipes serve as the heat eliminating mechanism is discussed

The NBS: Processing/Microstructure/Property Relationships in 2024 Aluminum Alloy Plates

NASA Technical Reports Server (NTRS)

Ives, L. K.; Swartzendruber, W. J.; Boettinger, W. J.; Rosen, M.; Ridder, S. D.

1983-01-01

As received plates of 2024 aluminum alloy were examined. Topics covered include: solidification segregation studies; microsegregation and macrosegregation in laboratory and commercially cast ingots; C-curves and nondestructive evaluation; time-temperature precipitation diagrams and the relationships between mechanical properties and NDE measurements; transmission electron microscopy studies; the relationship between microstructure and properties; ultrasonic characterization; eddy-current conductivity characterization; the study of aging process by means of dynamic eddy current measurements; and Heat flow-property predictions, property degradations due to improve quench from the solution heat treatment temperature.

Cloud Cover Increase with Increasing Aerosol Absorptivity: A Counterexample to the Conventional Semidirect Aerosol Effect

NASA Technical Reports Server (NTRS)

Perlwitz, Jan; Miller, Ron L.

2010-01-01

We reexamine the aerosol semidirect effect using a general circulation model and four cases of the single-scattering albedo of dust aerosols. Contrary to the expected decrease in low cloud cover due to heating by tropospheric aerosols, we find a significant increase with increasing absorptivity of soil dust particles in regions with high dust load, except during Northern Hemisphere winter. The strongest sensitivity of cloud cover to dust absorption is found over land during Northern Hemisphere summer. Here even medium and high cloud cover increase where the dust load is highest. The cloud cover change is directly linked to the change in relative humidity in the troposphere as a result of contrasting changes in specific humidity and temperature. More absorption by aerosols leads to larger diabatic heating and increased warming of the column, decreasing relative humidity. However, a corresponding increase in the specific humidity exceeds the temperature effect on relative humidity. The net effect is more low cloud cover with increasing aerosol absorption. The higher specific humidity where cloud cover strongly increases is attributed to an enhanced convergence of moisture driven by dust radiative heating. Although in some areas our model exhibits a reduction of low cloud cover due to aerosol heating consistent with the conventional description of the semidirect effect, we conclude that the link between aerosols and clouds is more varied, depending also on changes in the atmospheric circulation and the specific humidity induced by the aerosols. Other absorbing aerosols such as black carbon are expected to have a similar effect.

The effect of cover use on plastic pyrolysis reactor heating process

NASA Astrophysics Data System (ADS)

Armadi, Benny H.; Rangkuti, Chalilullah; Fauzi, M. D.; Permatasari, R.

2017-03-01

Plastic pyrolysis process to produce liquid fuel is an endothermic process that uses heat from the combustion of fuel as heat source. The reactor used is usually a vertical cylindrical in shape, with LPG fuel combustion under the flat bottom of the reactor, and the combustion gases is dispersed into the surrounding environment, so that heat transferred to the plastic inside the reactor is not effective, causing high LPG consumption. In this study, the reactor is made of stainless steel plate, with a vertical cylindrical shape, with a basic cylindrical conical truncated by a pit pass hot flue gas in the middle that serves to deliver flue gas into the chimney. The contact area between the hot combusted LPG gases to the processed plastic inside the reactor becomes bigger and gets better heat transfer, and required less LPG consumption. For more effective heat transfer process, an outer cover of this reactor was made and the relatively hot combustion gases are used to heat the outside of the reactor by directing the flow of the flue gas from the chimney down along the outer wall of the reactor and out the bottom lid. This construction makes the heating process to be faster and the LPG fuel is used more efficiently. From the measurements, it was found to raise 1°C of temperature inside the covered reactor, the LPG consumed is 0.59 gram, and if the reactor cover is removed, the gas demand will rise nearly threefold to 1.43 grams. With this method, in addition to reducing the rate of heat loss will also help reduce LPG consumption significantly.

An integrated approach to the remote sensing of floating ice

NASA Technical Reports Server (NTRS)

Campbell, W. J.; Ramseier, R. O.; Weeks, W. F.; Gloersen, P.

1976-01-01

Review article on remote sensing applications to glaciology. Ice parameters sensed include: ice cover vs open water, ice thickness, distribution and morphology of ice formations, vertical resolution of ice thickness, ice salinity (percolation and drainage of brine; flushing of ice body with fresh water), first-year ice and multiyear ice, ice growth rate and surface heat flux, divergence of ice packs, snow cover masking ice, behavior of ice shelves, icebergs, lake ice and river ice; time changes. Sensing techniques discussed include: satellite photographic surveys, thermal IR, passive and active microwave studies, microwave radiometry, microwave scatterometry, side-looking radar, and synthetic aperture radar. Remote sensing of large aquatic mammals and operational ice forecasting are also discussed.

Contrasting Convective Flux Gradients in the U.S. Corn Belt as a Result of Vegetation Land Cover Type

NASA Astrophysics Data System (ADS)

Hiestand, M.

2017-12-01

Phenological differences between extensive croplands and remnant forests in the U.S. Corn Belt have been suggested as enhancing spatial gradients of latent and sensible heat fluxes that contribute to the distribution and amounts of convective rainfall on mesoscales. However, the exact magnitude of the intra-seasonal variability in convective fluxes between these two land-cover types has yet to be quantified. Previous work suggesting that non-classical mesoscale circulations operate within the Corn Belt has not involved direct flux observations obtained using the eddy flux covariance technique. This study compares five day running means of daily heat fluxes between two Ameriflux towers (US-Bo1 in Illinois and US-MMS in Indiana) representing rain-fed cropland and remnant forest, respectively for the growing seasons of 1999-2008. Latent heat values normalized to the net radiation show higher rates of evapotranspiration at the forested site than over the cropland during the start of the growing season. However, toward the end of the growing season, latent heat fluxes from the forest decrease and the cropland becomes the dominate source of evapotranspiration. Conversely, croplands dominate sensible heat fluxes at the start of the growing season whereas the remnant forests are associated with strong sensible heat fluxes in late summer. These intra-seasonal spatial differences of latent and sensible heat fluxes across the Corn Belt imply differences in moisture pooling that are suggested as enhancing atmospheric convection during favorable synoptic conditions, especially near the boundaries of these two land cover types. Understanding the physical mechanisms by which the spatial distribution of vegetated land cover can generate contrasting latent and sensible heat fluxes will lay the groundwork for improving mesoscale precipitation forecasts in the Corn Belt, and determining the possible impacts of ongoing land-cover and climate changes there.

Solar Heating System installed at Belz Investment Company, Memphis, Tennessee

NASA Technical Reports Server (NTRS)

1981-01-01

A hot air solar system which utilizes flat plate air collectors is discussed. Collector areas for each of four buildings cover 780 sq ft, with storage capacity of 390 cu ft per building. The air system has a special air handling unit to move air through the collectors and into and out of the rock storage, with connection to the air duct distribution system. The heat of the motor is added to the heat delivered to the system. The solar system also includes four motorized special low leakage dampers and two gravity fabric dampers. The system is automatically controlled by a solid state controller with three thermistors: one located in the collectors, one in the rock box to plenum, one in the return air duct from the heated space. A three stage heating thermostat, located in the conditioned space, controls the operation.

Nest substrate reflects incubation style in extant archosaurs with implications for dinosaur nesting habits.

PubMed

Tanaka, Kohei; Zelenitsky, Darla K; Therrien, François; Kobayashi, Yoshitsugu

2018-03-15

Dinosaurs thrived and reproduced in various regions worldwide, including the Arctic. In order to understand their nesting in diverse or extreme environments, the relationships between nests, nesting environments, and incubation methods in extant archosaurs were investigated. Statistical analyses reveal that species of extant covered nesters (i.e., crocodylians and megapodes) preferentially select specific sediments/substrates as a function of their nesting style and incubation heat sources. Relationships between dinosaur eggs and the sediments in which they occur reveal that hadrosaurs and some sauropods (i.e., megaloolithid eggs) built organic-rich mound nests that relied on microbial decay for incubation, whereas other sauropods (i.e., faveoloolithid eggs) built sandy in-filled hole nests that relied on solar or potentially geothermal heat for incubation. Paleogeographic distribution of mound nests and sandy in-filled hole nests in dinosaurs reveals these nest types produced sufficient incubation heat to be successful up to mid latitudes (≤47°), 10° higher than covered nesters today. However, only mound nesting and likely brooding could have produced sufficient incubation heat for nesting above the polar circle (>66°). As a result, differences in nesting styles may have placed restrictions on the reproduction of dinosaurs and their dispersal at high latitudes.

The importance of land cover change across urban-rural typologies for climate modeling.

PubMed

Vargo, Jason; Habeeb, Dana; Stone, Brian

2013-01-15

Land cover changes affect local surface energy balances by changing the amount of solar energy reflected, the magnitude and duration over which absorbed energy is released as heat, and the amount of energy that is diverted to non-heating fluxes through evaporation. However, such local influences often are only crudely included in climate modeling exercises, if at all. A better understanding of local land conversion dynamics can serve to inform inputs for climate models and increase the role for land use planning in climate management policy. Here we present a new approach for projecting and incorporating metropolitan land cover change into mesoscale climate and other environmental assessment models. Our results demonstrate the relative contributions of different land development patterns to land cover change and conversion and suggest that regional growth management strategies serving to increase settlement densities over time can have a significant influence on the rate of deforestation per unit of population growth. Employing the approach presented herein, the impacts of land conversion on climate change and on parallel environmental systems and services, such as ground water recharge, habitat provision, and food production, may all be investigated more closely and managed through land use planning. Copyright © 2012 Elsevier Ltd. All rights reserved.

Industrial robots: Handbook

NASA Astrophysics Data System (ADS)

Kozyrev, Iu. G.

Topics covered include terms, definitions, and classification; operator-directed manipulators; autooperators as used in automated pressure casting; construction and application of industrial robots; and the operating bases of automated systems. Attention is given to adaptive and interactive robots; gripping mechanisms; applications to foundary production, press-forging plants, heat treatment, welding, and assembly operations. A review of design recommendations includes a determination of fundamental structural and technological indicators for industrial robots and a consideration of drive mechanisms.

Supraglacial lakes on Himalayan debris-covered glacier (Invited)

NASA Astrophysics Data System (ADS)

Sakai, A.; Fujita, K.

2013-12-01

Debris-covered glaciers are common in many of the world's mountain ranges, including in the Himalayas. Himalayan debris-covered glacier also contain abundant glacial lakes, including both proglacial and supraglacial types. We have revealed that heat absorption through supraglacial lakes was about 7 times greater than that averaged over the whole debris-covered zone. The heat budget analysis elucidated that at least half of the heat absorbed through the water surface was released with water outflow from the lakes, indicating that the warm water enlarge englacial conduits and produce internal ablation. We observed some portions at debris-covered area has caved at the end of melting season, and ice cliff has exposed at the side of depression. Those depression has suggested that roof of expanded water channels has collapsed, leading to the formation of ice cliffs and new lakes, which would accelerate the ablation of debris-covered glaciers. Almost glacial lakes on the debris-covered glacier are partially surrounded by ice cliffs. We observed that relatively small lakes had non-calving, whereas, calving has occurred at supraglacial lakes with fetch larger than 80 m, and those lakes expand rapidly. In the Himalayas, thick sediments at the lake bottom insulates glacier ice and lake water, then the lake water tends to have higher temperature (2-4 degrees C). Therefore, thermal undercutting at ice cliff is important for calving processes in the glacial lake expansion. We estimated and subaqueous ice melt rates during the melt and freeze seasons under simple geomorphologic conditions. In particular, we focused on valley wind-driven water currents in various fetches during the melt season. Our results demonstrate that the subaqueous ice melt rate exceeds the ice-cliff melt rate above the water surface when the fetch is larger than 20 m with the water temperature of 2-4 degrees C. Calculations suggest that onset of calving due to thermal undercutting is controlled by water currents driven by winds at the lake surface with a positive feedback process. The risk of GLOFs (glacial lake outburst flood) are analysed for Himalayan glacial lakes. We proposed an objective index for GLOF probability, based on depression angle from the lakeshore, which allows the lakes to be assessed using remotely sensed digital elevation models (DEMs). The index was verified by pre-GLOF topography derived by spy satellite imageries. We screened 2800 Himalayan glacial lakes and identified 49 lakes with potential flood volumes over 10 million m3.

Numerical modelling of methane oxidation efficiency and coupled water-gas-heat reactive transfer in a sloping landfill cover.

PubMed

Feng, S; Ng, C W W; Leung, A K; Liu, H W

2017-10-01

Microbial aerobic methane oxidation in unsaturated landfill cover involves coupled water, gas and heat reactive transfer. The coupled process is complex and its influence on methane oxidation efficiency is not clear, especially in steep covers where spatial variations of water, gas and heat are significant. In this study, two-dimensional finite element numerical simulations were carried out to evaluate the performance of unsaturated sloping cover. The numerical model was calibrated using a set of flume model test data, and was then subsequently used for parametric study. A new method that considers transient changes of methane concentration during the estimation of the methane oxidation efficiency was proposed and compared against existing methods. It was found that a steeper cover had a lower oxidation efficiency due to enhanced downslope water flow, during which desaturation of soil promoted gas transport and hence landfill gas emission. This effect was magnified as the cover angle and landfill gas generation rate at the bottom of the cover increased. Assuming the steady-state methane concentration in a cover would result in a non-conservative overestimation of oxidation efficiency, especially when a steep cover was subjected to rainfall infiltration. By considering the transient methane concentration, the newly-modified method can give a more accurate oxidation efficiency. Copyright © 2017. Published by Elsevier Ltd.

Evaluation of dispersion strengthened nickel-base alloy heat shields for space shuttle application

NASA Technical Reports Server (NTRS)

Johnson, R., Jr.; Killpatrick, D. H.

1975-01-01

The design, fabrication, and testing of a full-size, full-scale TD Ni-20Cr heat shield test array in simulated mission environments is described along with the design and fabrication of two additional full-size, full-scale test arrays to be tested in flowing gas test facilities at the NASA Langley Research Center. Cost and reusability evaluations of TD Ni-20Cr heat shield systems are presented, and weight estimates of a TD Ni-20Cr heat shield system for use on a shuttle orbiter vehicle are made. Safe-line expectancy of a TD Ni-20Cr heat shield system is assessed. Non-destructive test techniques are evaluated to determine their effectiveness in quality assurance checks of TD Ni-20Cr components such as heat shields, heat shield supports, close-out panels, formed cover strips, and edge seals. Results of tests on a braze reinforced full-scale, subsize panel are included. Results show only minor structural degradation in the main TD Ni-20Cr heat shields of the test array during simulated mission test cycles.

Seasonal cycle of the mixed-layer heat and freshwater budget in the eastern tropical Atlantic

NASA Astrophysics Data System (ADS)

Rath, Willi; Dengler, Marcus; Lüdke, Jan; Schmidtko, Sunke; Schlundt, Michael; Brandt, Peter; Partners, Preface

2016-04-01

A new seasonal mixed-layer heat flux climatology is used to explore the mechanisms driving seasonal variability of sea surface temperature and salinity in the eastern tropical Atlantic (ETA) with a focus on the eastern boundary upwelling regions. Until recently, large areas at the continental margins of the ETA were not well covered by publically available hydrographic data hampering a detailed understanding of the involved processes. In a collaborative effort between African and European partners within the EU-funded PREFACE program, a new seasonal climatology for different components of the heat and freshwater budget was compiled for the ETA using all publically available hydrographic data sets and a large trove of previously not-publically available hydrographic measurements from the territorial waters of western African countries, either from national programs or from the FAO supported EAF-Nansen program. The publically available data includes hydrographic data from global data repositories including most recent ARGO floats and glider measurements. This data set was complemented by velocity data from surface drifter and ARGO floats to allow determining horizontal heat and freshwater advection. Monthly means of air-sea heat fluxes were derived from the TropFlux climatology while precipitation rates were derived from monthly mean fields of the Global Precipitation Climatology Project. Finally, microstructure data from individual measurement campaigns allow estimating diapycnal heat and salt fluxes for certain regions during specific months. A detailed analysis of the seasonal cycle of mixed-layer heat and freshwater balance in previously poorly covered regions in the eastern tropical Atlantic upwelling is presented. In both eastern boundary upwelling region, off Senegal/Mauritania and off Angola/Namibia, average net surface heat fluxes warm the mixed layer at a rate between 50 and 80 W/m2 with maxima in the respective summer seasons. Horizontal advection contributed to cooling of the mixed layer but a residual cooling term remains in both upwelling regions. A surprising result is that this residual is largest in the Angolan upwelling region, where upwelling-favourable winds are generally weaker than off Namibia and in the north-eastern upwelling region. The contributions of windstress-derived vertical advection and diapycnal heat and freshwater fluxes are discussed. In addition, the TropFlux climatology is evaluated against radiative and turbulent ocean-atmosphere heat and freshwater fluxes derived from ship-board observations.

Thermodynamic Properties of Nitrogen Including Liquid and Vapor Phases from 63K to 2000K with Pressures to 10,000 Bar

NASA Technical Reports Server (NTRS)

Jacobsen, Richard T.; Stewart, Richard B.

1973-01-01

Tables of thermodynamic properties of nitrogen are presented for the liquid and vapor phases for temperatures from the freezing line to 2000K and pressures to 10,000 bar. The tables include values of density, internal energy, enthalpy, entropy, isochoric heat capacity, isobaric heat capacity velocity of sound, the isotherm derivative, and the isochor derivative. The thermodynamic property tables are based on an equation of state, P=P (p,T), which accurately represents liquid and gaseous nitrogen for the range of pressures and temperatures covered by the tables. Comparisons of property values calculated from the equation of state with measured values for P-p-T, heat capacity, enthalpy, latent heat, and velocity of sound are included to illustrate the agreement between the experimental data and the tables of properties presented here. The coefficients of the equation of state were determined by a weighted least squares fit to selected P-p-T data and, simultaneously, to isochoric heat capacity data determined by corresponding states analysis from oxygen data, and to data which define the phase equilibrium criteria for the saturated liquid and the saturated vapor. The vapor pressure equation, melting curve equation, and an equation to represent the ideal gas heat capacity are also presented. Estimates of the accuracy of the equation of state, the vapor pressure equation, and the ideal gas heat capacity equation are given. The equation of state, derivatives of the equation, and the integral functions for calculating derived thermodynamic properties are included.

Data and techniques for studying the urban heat island effect in Johannesburg

NASA Astrophysics Data System (ADS)

Hardy, C. H.; Nel, A. L.

2015-04-01

The city of Johannesburg contains over 10 million trees and is often referred to as an urban forest. The intra-urban spatial variability of the levels of vegetation across Johannesburg's residential regions has an influence on the urban heat island effect within the city. Residential areas with high levels of vegetation benefit from cooling due to evapo-transpirative processes and thus exhibit weaker heat island effects; while their impoverished counterparts are not so fortunate. The urban heat island effect describes a phenomenon where some urban areas exhibit temperatures that are warmer than that of surrounding areas. The factors influencing the urban heat island effect include the high density of people and buildings and low levels of vegetative cover within populated urban areas. This paper describes the remote sensing data sets and the processing techniques employed to study the heat island effect within Johannesburg. In particular we consider the use of multi-sensorial multi-temporal remote sensing data towards a predictive model, based on the analysis of influencing factors.

Variances in solar collector performance predictions due to different methods of evaluating wind heat transfer coefficients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramsey, J.W.; Charmchi, M.

1980-11-01

The performance of several solar collector configurations has been predicted using both inappropriate and appropriate relations to evaluate the wind-related heat transfer coefficient. The combinations analyzed are: one or two covers and a selectively absorbing surface coating, and one or two covers and a nonselectively absorbing surface coating all collectors are of the basic liquid heating type. It is shown that the optimum results are obtained by using a global correlation equation proposed by Sparrow et al. (1979).

A Federal Employee's Family Preparedness Guide.

ERIC Educational Resources Information Center

Office of Personnel Management, Washington, DC.

This document outlines what families can do before, during, and after an emergency. The first section covers preparations that can be made before an emergency occurs and includes the creation of a family emergency plan and an "emergency go kit," which can save time if one has to evacuate or go without heat, electricity, or water for a…

Energy. Stop Faking It! Finally Understanding Science So You Can Teach It.

ERIC Educational Resources Information Center

Robertson, William C.

This book explains science concepts in a manner in which non-science teachers and parents can understand and learn science through activities. The concepts covered in this book include energy, simple machines, temperature, and heat transfer. Each chapter is supported with internet resources available at SciLinks and ends with a summary and…

Heat Sink Design and Optimization

DTIC Science & Technology

2015-12-01

HEAT SINK DESIGN AND OPTIMIZATION I...REPORT DATE (DD-MM-YYYY) December 2015 2. REPORT TYPE Final 3. DATES COVERED (From – To) 4. TITLE AND SUBTITLE HEAT SINK DESIGN AND OPTIMIZATION...distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Heat sinks are devices that are used to enhance heat dissipation

Application of spatially gridded temperature and land cover data sets for urban heat island analysis

USGS Publications Warehouse

Gallo, Kevin; Xian, George Z.

2014-01-01

Two gridded data sets that included (1) daily mean temperatures from 2006 through 2011 and (2) satellite-derived impervious surface area, were combined for a spatial analysis of the urban heat-island effect within the Dallas-Ft. Worth Texas region. The primary advantage of using these combined datasets included the capability to designate each 1 × 1 km grid cell of available temperature data as urban or rural based on the level of impervious surface area within the grid cell. Generally, the observed differences in urban and rural temperature increased as the impervious surface area thresholds used to define an urban grid cell were increased. This result, however, was also dependent on the size of the sample area included in the analysis. As the spatial extent of the sample area increased and included a greater number of rural defined grid cells, the observed urban and rural differences in temperature also increased. A cursory comparison of the spatially gridded temperature observations with observations from climate stations suggest that the number and location of stations included in an urban heat island analysis requires consideration to assure representative samples of each (urban and rural) environment are included in the analysis.

Monitoring the effects of land use/landcover changes on urban heat island

NASA Astrophysics Data System (ADS)

Gee, Ong K.; Sarker, Md Latifur Rahman

2013-10-01

Urban heat island effects are well known nowadays and observed in cities throughout the World. The main reason behind the effects of urban heat island (UHI) is the transformation of land use/ land cover, and this transformation is associated with UHI through different actions: i) removal of vegetated areas, ii) land reclamation from sea/river, iii) construction of new building as well as other concrete structures, and iv) industrial and domestic activity. In rapidly developing cities, urban heat island effects increases very hastily with the transformation of vegetated/ other types of areas into urban surface because of the increasing population as well as for economical activities. In this research the effect of land use/ land cover on urban heat island was investigated in two growing cities in Asia i.e. Singapore and Johor Bahru, (Malaysia) using 10 years data (from 1997 to 2010) from Landsat TM/ETM+. Multispectral visible band along with indices such as Normalized Difference Vegetation Index (NDVI), Normalized Difference Build Index (NDBI), and Normalized Difference Bareness Index (NDBaI) were used for the classification of major land use/land cover types using Maximum Likelihood Classifiers. On the other hand, land surface temperature (LST) was estimated from thermal image using Land Surface Temperature algorithm. Emissivity correction was applied to the LST map using the emissivity values from the major land use/ land cover types, and validation of the UHI map was carried out using in situ data. Results of this research indicate that there is a strong relationship between the land use/land cover changes and UHI. Over this 10 years period, significant percentage of non-urban surface was decreased but urban heat surface was increased because of the rapid urbanization. With the increase of UHI effect it is expected that local urban climate has been modified and some heat related health problem has been exposed, so appropriate measure should be taken in order to reduce UHI effects as soon as possible.

Method for the hydrogenation of poly-si

DOEpatents

Wang, Qi

2013-11-12

A method for hydrogenating poly-si. Poly-si is placed into the interior of a chamber. A filament is placed into the interior of a chamber. The base pressure of the interior of the chamber is evacuated, preferably to 10.sup.-6 Torr or less. The poly-si is heated for a predetermined poly-si heating time. The filament is heated by providing an electrical power to the filament. Hydrogen is supplied into the pressurized interior of the chamber comprising the heated poly-si and the heated filament. Atomic hydrogen is produced by the filament at a rate whereby the atomic hydrogen surface density at the poly-si is less than the poly-si surface density. Preferably, the poly-si is covered from the atomic hydrogen produced by the heated filament for a first predetermined covering time. Preferably, the poly-si is then uncovered from the atomic hydrogen produced by the heated filament for a first hydrogenation time.

Supersonic combustion engine testbed, heat lightning

NASA Technical Reports Server (NTRS)

Hoying, D.; Kelble, C.; Langenbahn, A.; Stahl, M.; Tincher, M.; Walsh, M.; Wisler, S.

1990-01-01

The design of a supersonic combustion engine testbed (SCET) aircraft is presented. The hypersonic waverider will utilize both supersonic combustion ramjet (SCRAMjet) and turbofan-ramjet engines. The waverider concept, system integration, electrical power, weight analysis, cockpit, landing skids, and configuration modeling are addressed in the configuration considerations. The subsonic, supersonic and hypersonic aerodynamics are presented along with the aerodynamic stability and landing analysis of the aircraft. The propulsion design considerations include: engine selection, turbofan ramjet inlets, SCRAMjet inlets and the SCRAMjet diffuser. The cooling requirements and system are covered along with the topics of materials and the hydrogen fuel tanks and insulation system. A cost analysis is presented and the appendices include: information about the subsonic wind tunnel test, shock expansion calculations, and an aerodynamic heat flux program.

Quartz resonator processing system

DOEpatents

Peters, Roswell D. M.

1983-01-01

Disclosed is a single chamber ultra-high vacuum processing system for the oduction of hermetically sealed quartz resonators wherein electrode metallization and sealing are carried out along with cleaning and bake-out without any air exposure between the processing steps. The system includes a common vacuum chamber in which is located a rotatable wheel-like member which is adapted to move a plurality of individual component sets of a flat pack resonator unit past discretely located processing stations in said chamber whereupon electrode deposition takes place followed by the placement of ceramic covers over a frame containing a resonator element and then to a sealing stage where a pair of hydraulic rams including heating elements effect a metallized bonding of the covers to the frame.

A broad look at solar physics adapted from the solar physics study of August 1975

NASA Technical Reports Server (NTRS)

Parker, E.; Timothy, A.; Beckers, J.; Hundhausen, A.; Kundu, M. R.; Leith, C. E.; Lin, R.; Linsky, J.; Macdonald, F. B.; Noyes, R.

1979-01-01

The current status of our knowledge of the basic mechanisms involved in fundamental solar phenomena is reviewed. These include mechanisms responsible for heating the corona, the generation of the solar wind, the particle acceleration in flares, and the dissipation of magnetic energy in field reversal regions, known as current sheets. The discussion covers solar flares and high-energy phenomena, solar active regions; solar interior, convection, and activity; the structure and energetics of the quiet solar atmosphere; the structure of the corona; the solar composition; and solar terrestrial interactions. It also covers a program of solar research, including the special observational requirements for spectral and angular resolution, sensitivity, time resolution, and duration of the techniques employed.

Passive thermosyphon solar heating and cooling module with supplementary heating

NASA Technical Reports Server (NTRS)

1977-01-01

A collection of three quarterly reports from Sigma Research, Inc., covering progress and status from January through September 1977 are presented. Three heat exchangers are developed for use in a solar heating and cooling system for installation into single-family dwellings. Each exchanger consists of one heating and cooling module and one submerged electric water heating element.

Aerothermodynamic Design of the Mars Science Laboratory Backshell and Parachute Cone

NASA Technical Reports Server (NTRS)

Edquist, Karl T.; Dyakonov, Artem A.; Wright, Michael J.; Tang, Chun Y.

2009-01-01

Aerothermodynamic design environments are presented for the Mars Science Laboratory entry capsule backshell and parachute cone. The design conditions are based on Navier-Stokes flowfield simulations on shallow (maximum total heat load) and steep (maximum heat flux) design entry trajectories from a 2009 launch. Transient interference effects from reaction control system thruster plumes were included in the design environments when necessary. The limiting backshell design heating conditions of 6.3 W/sq cm for heat flux and 377 J/sq cm for total heat load are not influenced by thruster firings. Similarly, the thrusters do not affect the parachute cover lid design environments (13 W/sq cm and 499 J/sq cm). If thruster jet firings occur near peak dynamic pressure, they will augment the design environments at the interface between the backshell and parachute cone (7 W/sq cm and 174 J/sq cm). Localized heat fluxes are higher near the thruster fairing during jet firings, but these areas did not require additional thermal protection material. Finally, heating bump factors were developed for antenna radomes on the parachute cone

Heat Coulomb blockade of one ballistic channel

NASA Astrophysics Data System (ADS)

Sivre, E.; Anthore, A.; Parmentier, F. D.; Cavanna, A.; Gennser, U.; Ouerghi, A.; Jin, Y.; Pierre, F.

2018-02-01

Quantum mechanics and Coulomb interaction dictate the behaviour of small circuits. The thermal implications cover fundamental topics from quantum control of heat to quantum thermodynamics, with prospects of novel thermal machines and an ineluctably growing influence on nanocircuit engineering. Experimentally, the rare observations thus far include the universal thermal conductance quantum and heat interferometry. However, evidence for many-body thermal effects paving the way to markedly different heat and electrical behaviours in quantum circuits remains wanting. Here we report on the observation of the Coulomb blockade of electronic heat flow from a small metallic circuit node, beyond the widespread Wiedemann-Franz law paradigm. We demonstrate this thermal many-body phenomenon for perfect (ballistic) conduction channels to the node, where it amounts to the universal suppression of precisely one quantum of conductance for the transport of heat, but none for electricity. The inter-channel correlations that give rise to such selective heat current reduction emerge from local charge conservation, in the floating node over the full thermal frequency range (<~temperature × kB/h). This observation establishes the different nature of the quantum laws for thermal transport in nanocircuits.

Methods for heat transfer and temperature field analysis of the insulated diesel phase 2 progress report

NASA Technical Reports Server (NTRS)

Morel, T.; Kerlbar, R.; Fort, E. F.; Blumberg, P. N.

1985-01-01

This report describes work done during Phase 2 of a 3 year program aimed at developing a comprehensive heat transfer and thermal analysis methodology for design analysis of insulated diesel engines. The overall program addresses all the key heat transfer issues: (1) spatially and time-resolved convective and radiative in-cylinder heat transfer, (2) steady-state conduction in the overall structure, and (3) cyclical and load/speed temperature transients in the engine structure. During Phase 2, radiation heat transfer model was developed, which accounts for soot formation and burn up. A methodology was developed for carrying out the multi-dimensional finite-element heat conduction calculations within the framework of thermodynamic cycle codes. Studies were carried out using the integrated methodology to address key issues in low heat rejection engines. A wide ranging design analysis matrix was covered, including a variety of insulation strategies, recovery devices and base engine configurations. A single cylinder Cummins engine was installed at Purdue University, and it was brought to a full operational status. The development of instrumentation was continued, concentrating on radiation heat flux detector, total heat flux probe, and accurate pressure-crank angle data acquisition.

Tundra shrub effects on growing season energy and carbon dioxide exchange

NASA Astrophysics Data System (ADS)

Lafleur, Peter M.; Humphreys, Elyn R.

2018-05-01

Increased shrub cover on the Arctic tundra is expected to impact ecosystem-atmosphere exchanges of carbon and energy resulting in feedbacks to the climate system, yet few direct measurements of shrub tundra-atmosphere exchanges are available to corroborate expectations. Here we present energy and carbon dioxide (CO2) fluxes measured using the eddy covariance technique over six growing seasons at three closely located tundra sites in Canada’s Low Arctic. The sites are dominated by the tundra shrub Betula glandulosa, but percent cover varies from 17%–60% and average shrub height ranges from 18–59 cm among sites. The site with greatest percent cover and height had greater snow accumulation, but contrary to some expectations, it had similar late-winter albedo and snow melt dates compared to the other two sites. Immediately after snowmelt latent heat fluxes increased more slowly at this site compared to the others. Yet by the end of the growing season there was little difference in cumulative latent heat flux among the sites, suggesting evapotranspiration was not increased with greater shrub cover. In contrast, lower albedo and less soil thaw contributed to greater summer sensible heat flux at the site with greatest shrub cover, resulting in greater total atmospheric heating. Net ecosystem exchange of CO2 revealed the potential for enhanced carbon cycling rates under greater shrub cover. Spring CO2 emissions were greatest at the site with greatest percent cover of shrubs, as was summer net uptake of CO2. The seasonal net sink for CO2 was ~2 times larger at the site with the greatest shrub cover compared to the site with the least shrub cover. These results largely agree with expectations that the growing season feedback to the atmosphere arising from shrub expansion in the Arctic has the potential to be negative for CO2 fluxes but positive for turbulent energy fluxes.

Push-pull radio frequency circuit with integral transistion to waveguide output

DOEpatents

Bennett, Wilfred P.

1987-01-01

A radio frequency circuit for ICRF heating includes a resonant push-pull circuit, a double ridged rectangular waveguide, and a coupling transition which joins the waveguide to the resonant circuit. The resonant circuit includes two cylindrical conductors mounted side by side and two power vacuum tubes attached to respective ends of a cylindrical conductor. A conductive yoke is located at the other end of the cylindrical conductors to short circuit the two cylindrical conductors. The coupling transition includes two relatively flat rectangular conductors extending perpendicular to the longitudinal axes of a respective cylindrical conductor to which the flat conductor is attached intermediate the ends thereof. Conductive side covers and end covers are also provided for forming pockets in the waveguide into which the flat conductors extend when the waveguide is attached to a shielding enclosure surrounding the resonant circuit.

The relation between land-cover and the urban heat island in northeastern Puerto Rico

Treesearch

David J.R. Murphy; Myrna Hall; Charles Hall; Gordon Heisler; Steve Stehman

2007-01-01

As development continues in Puerto Rico, forests and grasslands are being converted to impervious cover, changing the magnitude and geographic range of the Urban Heat Island (UHI). As part of the U.S. National Science Foundation Long Term Ecological Research Program, this study aims to quantify the various meteorological effects that urbanization may be imparting on...

10 CFR 431.408 - Preemption of State regulations for covered equipment other than electric motors and commercial...

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Preemption of State regulations for covered equipment other than electric motors and commercial heating, ventilating, air-conditioning and water heating products. 431.408 Section 431.408 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMEN...

Observations of the Winter Thermal Structure of Lake Superior

NASA Astrophysics Data System (ADS)

Titze, Daniel James

Moored thermistor strings that span the water column have been deployed at up to seven locations throughout Lake Superior from 2005 through present, producing a unique year-round record of the thermal structure of a large lake. This extensive temperature record reveals significant interannual and spatial variability in Lake Superior's winter heat content, thermocline depth, and phenology. Of particular mention is a stark contrast in thermal structure between the cold, icy winter of 2009 and the much warmer winter of 2012, during which especially strong and weak negative stratification was observed, respectively. Significant interannual and spatial variability was also observed in Lake Superior ice cover, as shown through data extracted from Ice Mapping System satellite imagery (NOAA/NESDIS 2004). When water column heat content was estimated from temperature data and analyzed in concert with lake ice-cover data, it was found that ice cover can inhibit heat flux between the lake and the atmosphere, and that spatial variability in ice cover can translate into spatial variability in end-of-winter heat content. Such variability in end-of-winter heat content is found to be preserved through the spring warming season, and is strongly correlated with variability in the timing of the onset of summer stratification, with regions that have warmer end-of-winter water columns stratifying earlier than regions with colder end-of-winter water-columns.

Turbine vane structure

DOEpatents

Irwin, John A.

1980-08-19

A liquid cooled stator blade assembly for a gas turbine engine includes an outer shroud having a pair of liquid inlets and a pair of liquid outlets supplied through a header and wherein means including tubes support the header radially outwardly of the shroud and also couple the header with the pair of liquid inlets and outlets. A pair of turbine vanes extend radially between the shroud and a vane platform to define a gas turbine motive fluid passage therebetween; and each of the vanes is cooled by an internal body casting of super alloy material with a grooved layer of highly heat conductive material that includes spaced apart flat surface trailing edges in alignment with a flat trailing edge of the casting joined to wall segments of the liner which are juxtaposed with respect to the internal casting to form an array of parallel liquid inlet passages on one side of the vane and a second plurality of parallel liquid return passages on the opposite side of the vane; and a superalloy heat and wear resistant imperforate skin covers the outer surface of the composite blade including the internal casting and the heat conductive layer; a separate trailing edge section includes an internal casting and an outer skin butt connected to the end surfaces of the internal casting and the heat conductive layer to form an easily assembled liquid cooled trailing edge section in the turbine vane.

El Toro Library Solar Heating and Cooling Demonstration Project. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This report is divided into a number of essentially independent sections, each of which covers a specific topic. The sections, and the topics covered, are as follows. Section 1 provides a brief summary description of the solar energy heating and cooling system including the key final design parameters. Section 2 contains a copy of the final Acceptance Test Report. Section 3 consists of a reduced set of final updated as-built mechanical, electrical, control and instrumentations drawings of the solar energy heating and cooling system. Section 4 provides a summary of system maintenance requirements, in the form of a maintenance schedulemore » which lists necessary maintenance tasks to be performed at monthly, quarterly, semi-annual, and annual intervals. Section 5 contains a series of photographs of the final solar energy system installation, including the collector field and the mechanical equipment room. Section 6 provides a concise summary of system operation and performance for the period of December 1981 through June 1982, as measured, computed and reported by Vitro Laboratories Division of Automation Industries, Inc., for the DOE National Solar Data Network. Section 7 provides a summary of key as-built design parameters, compared with the corresponding original design concept parameters. Section 8 provides a description of a series of significant problems encountered during construction, start-up and check-out of the solar energy heating and cooling system, together with the method employed to solve the problem at the time and/or recommendations for avoiding the problem in the future design of similar systems. Appendices A through H contain the installation, operation and maintenance submittals of the various manufacturers on the major items of equipment in the system. Reference CAPE-2823.« less

Sizing up skylights

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warner, J.L.

1993-11-01

This article discusses various aspects of skylights. Designers, builders, and homeowners who understand the energy aspects of skylights can best select them for comfort as well as appearance. Topics covered include heat loss problems (convection, radiation); the sun and the sun angles; ventilation; skylight ratings for efficiency; pointers about what to look for; comparison of skylight and window U-Factors; ventilation. 3 figs., 1 tab.

Confounding factors in the use of the zero-heat-flow method for non-invasive muscle temperature measurement.

PubMed

Brajkovic, Dragan; Ducharme, Michel B

2005-07-01

This study evaluated a zero-heat-flow (ZHF), non-invasive temperature probe for in- vivo measurement of resting muscle temperature for up to 2 cm below the skin surface. The ZHF probe works by preventing heat loss from the tissue below the probe by actively heating the tissue until no temperature gradient exists across the probe. The skin temperature under the probe is then used as an indicator of the muscle temperature below. Eight subjects sat for 130 min during exposure to 28 degrees C air. Vastus lateralis (lateral thigh) muscle temperature was measured non-invasively using a ZHF probe which covered an invasive multicouple probe (which measured tissue temperature 0.5 cm, 1 cm, 1.5 cm, and 2 cm below the skin) located 15 cm superior to the patella (T (covered)). T (covered) was evaluated against an uncovered control multicouple probe located 20 cm superior to the patella (T (uncovered)). Rectal temperature and lateral thigh skin temperature were also measured. Mean T (uncovered) (based on average temperatures at the 0.5 cm, 1 cm, 1.5 cm, and 2 cm depths) and Mean T (covered) were similar from time 0 min to 60 min. However, when the ZHF was turned on at 70 min, Mean T (covered) increased by 2.11 +/- 0.20 degrees C by 130 min, while T (uncovered) remained stable. The ZHF probe temperature was similar to T (covered) at 1 cm and after time 85 min, significantly higher than T (covered) at the 0.5 cm, 1.5 cm, and 2 cm depths; however from a physiological standpoint, the temperatures between the different depths and the ZHF probe could be considered uniform (< or =0.2 degrees C separation). Rectal and thigh skin temperatures were stable at 36.99 +/- 0.08 degrees C and 32.82 +/- 0.23 degrees C, respectively. In conclusion, the non-invasive ZHF probe temperature was similar to the T (covered) temperatures directly measured up to 2 cm beneath the surface of the thigh, but all T (covered) temperatures were not representative of the true muscle temperature up to 2 cm below the skin because the ZHF probe heated the muscle by 2.11 +/- 0.20 degrees C during its operation.

A heat budget for the Stratus mooring in the southeast Pacific

NASA Astrophysics Data System (ADS)

Holte, J.; Straneo, F.; Weller, R. A.; Farrar, J. T.

2012-12-01

The surface layer of the southeast Pacific Ocean (SEP) requires an input of fresh, cold water to balance evaporation and heat gain from incoming solar radiation. Numerous processes contribute to closing the SEP's upper-ocean heat budget, including gyre circulation, Ekman transport and pumping, vertical mixing, and horizontal eddy heat flux divergence. However, there is little consensus on which processes are most important, as many modeling and observational studies have reported conflicting results. To examine how the SEP maintains relatively cool surface temperatures despite such strong surface forcing, we calculate a heat budget for the upper 250 m of the Stratus mooring. The Stratus mooring, deployed at 85(^o)W 20(^o)S since 2000, is in the center of the stratus cloud region. The surface buoy measures meteorological conditions and air-sea fluxes; the mooring line is heavily instrumented, measuring temperature, salinity, and velocity at approximately 15 to 20 depth levels. Our heat budget covers 2004 - 2010. The net air-sea heat flux over this period is 32 W m(^{-2}), approximately 2/3 of the flux over earlier periods. We use Argo profiles, relatively abundant in the region since 2004, to calculate horizontal temperature gradients. These gradients, coupled with the mooring velocity record, are used to estimate the advective heat flux. We find that the cool advective heat flux largely compensates the air-sea heat flux at the mooring; in our calculation this term includes the mean gyre circulation, horizontal Ekman transport, and some contribution from eddies. The passage of numerous eddies is evident in the mooring velocity record, but with the available data we cannot separate the eddy heat flux divergence from the mean heat advection. Vertical mixing and Ekman pumping across the base of the layer are both small.

Impacts of the thawing-freezing process on runoff generation in the Sources Area of the Yellow River on the northeastern Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Wu, Xiaoling; Xiang, Xiaohua; Qiu, Chao; Li, Li

2018-06-01

In cold regions, precipitation, air temperature and snow cover significantly influence soil water, heat transfer, the freezing-thawing processes of the active soil layer, and runoff generation. Hydrological regimes of the world's major rivers in cold regions have changed remarkably since the 1960s, but the mechanisms underlying the changes have not yet been fully understood. Using the basic physical processes for water and heat balances and transfers in snow covered soil, a water-heat coupling model for snow cover and its underlying soil layers was established. We found that freezing-thawing processes can affect the thickness of the active layer, storage capacity for liquid water, and subsequent surface runoffs. Based on calculations of thawing-freezing processes, we investigated hydrological processes at Qumalai. The results show that the water-heat coupling model can be used in this region to provide an understanding of the local movement of hydrological regimes.

Control of electro-chemical processes using energy harvesting materials and devices.

PubMed

Zhang, Yan; Xie, Mengying; Adamaki, Vana; Khanbareh, Hamideh; Bowen, Chris R

2017-12-11

Energy harvesting is a topic of intense interest that aims to convert ambient forms of energy such as mechanical motion, light and heat, which are otherwise wasted, into useful energy. In many cases the energy harvester or nanogenerator converts motion, heat or light into electrical energy, which is subsequently rectified and stored within capacitors for applications such as wireless and self-powered sensors or low-power electronics. This review covers the new and emerging area that aims to directly couple energy harvesting materials and devices with electro-chemical systems. The harvesting approaches to be covered include pyroelectric, piezoelectric, triboelectric, flexoelectric, thermoelectric and photovoltaic effects. These are used to influence a variety of electro-chemical systems such as applications related to water splitting, catalysis, corrosion protection, degradation of pollutants, disinfection of bacteria and material synthesis. Comparisons are made between the range harvesting approaches and the modes of operation are described. Future directions for the development of electro-chemical harvesting systems are highlighted and the potential for new applications and hybrid approaches are discussed.

Consequences of Changes in Vegetation and Snow Cover for Climate Feedbacks in Alaska and Northwest Canada

NASA Astrophysics Data System (ADS)

Euskirchen, E. S.; Breen, A. L.; Bennett, A.; Genet, H.; Lindgren, M.; Kurkowski, T. A.; McGuire, A. D.; Rupp, S. T.

2016-12-01

A continuing challenge in global change studies is to determine how land surface changes may impact atmospheric heating. Changes in vegetation and snow cover may lead to feedbacks to climate through changes in surface albedo and energy fluxes between the land and atmosphere. In addition to these biogeophysical feedbacks, biogeochemical feedbacks associated with changes in carbon (C) storage in the vegetation and soils may also influence climate. Here, using a transient biogeographic model (ALFRESCO) and an ecosystem model (DOS-TEM), we quantified the biogeophysical feedbacks due to changes in vegetation and snow cover across continuous permafrost to non-permafrost ecosystems in Alaska and northwest Canada. We also computed the changes in carbon storage in this region to provide a general assessment of the direction of the biogeochemical feedback. We considered four ecoregions, or Landscape Conservations Cooperatives (LCCs; including the Arctic, North Pacific, Western Alaska, and Northwest Boreal). We examined the 90-year period from 2010- 2099 using one future emission scenario (A1B), under outputs from two general circulation models (MPI-ECHAM5 and CCCMA-CGCM3.1). We consider a more comprehensive suite of possible feedbacks to climate due to shifts in vegetation than previous studies, including both boreal and tundra fire, an advance of treeline, reduction in forest cover due to drought, and increases in the distribution of shrub tundra. However, changes in snow cover still provided the dominant positive land surface feedback to atmospheric heating. This positive feedback was partially moderated by an increase in area burned in spruce forests and shrub tundra. Overall, increases in C storage in the vegetation and soils across the study region would act as a negative feedback to climate. By exploring these feedbacks, we can reach a more integrated understanding of the vulnerability of this region to changes in climate.

Hazards protection for space suits and spacecraft

NASA Technical Reports Server (NTRS)

Kosmo, Joseph J. (Inventor); Dawn, Frederic S. (Inventor)

1990-01-01

A flexible multi-layered covering article for protection against the hazards of exposure to the environment of outer space is disclosed. The covering includes an outer layer section comprising an outermost lamina of woven expanded tetrafluoroethylene yarns (Gore Tex) for protecting against abrasion and tearing, an underlying weave of meta-aramid yarns (Nomex) and para-aramid yarns (Kevlar) for particle impart protection, and electrostatic charge dissipation and control system incorporated therein, and a chemical contaminants control barrier applied as a coating. A middle section includes a succession of thermal insulating layers of polymeric thermoplastic or thermoforming material, each of which is coated with a metal deposit of high infra-red emissivity and low solar radiation absorption characteristics and separated from adjacent insulating layers by a low thermal conductance material. The covering further includes a radiation attenuating layer of a tungsten-loaded polymeric elastomer binder for protecting against bremsstrahlung radiation and an inner layer of rip-stop polyester material for abrasion protection. A chloroprene coating may be supplied the polyester-material for added micrometeroid protection. Securing means of low heat conductance material secures the multi-layers together as a laminar composite.

Pettit replaces the cover on an arm of Robonaut 2

NASA Image and Video Library

2012-03-13

ISS030-E-135119 (13 March 2012) --- In the International Space Station?s Destiny laboratory, NASA astronaut Don Pettit, Expedition 30 flight engineer, replaces the cover on an arm of Robonaut 2 after an upgrade to its systems. A heat sink was installed into both of the robot?s forearms to allow it to better dissipate heat and run for longer periods of time.

Conservation story takes to the road. [Potomac Edison Co. of Allegheny Power System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1975-02-15

Potomac Edison Co. personnel designed a compact mobile energy-conservation display that demonstrated energy conservation applications to industry, commerce, government, and educators; this van went on the road in December 1974. Among the displays in the vehicle were a working model of a liquid-heating tank that used floating plastic balls as a cover to conserve heat losses and evaporation, a microwave oven, types of insulation and their applications, and a demand controller designed to reduce consumer peak loads and demand charges. Other displays showed temperature and automatic time controls that could be used in locations unoccupied for various periods of timemore » and lighting applications that stressed use of the most efficient lamps and luminaires and emphasized equipment maintenance; a heat pump, a heat-recovery wheel, heat pipe, and model ''run-around system'' for recovering and reusing heat from various industrial processes were also included. (EAPA Ed. note: as of January 1976, plans were to refurbish, update, and put this van back on the road during the upcoming summer). (MCW)« less

Arc Jet Testing of the TIRS Cover Thermal Protection System for Mars Exploration Rover

NASA Technical Reports Server (NTRS)

Szalai, Christine E.; Chen, Y.-K.; Loomis, Mark; Hui, Frank; Scrivens, Larry

2002-01-01

This paper summarizes the arc jet test results of the Mars Exploration Rover (MER) Silicone Impregnated Reusable Ceramic Ablator (SIRCA) Transverse Impulse Rocket System (TIRS) Cover test series in the Panel Test Facility (PTF) at NASA Ames Research Center (ARC). NASA ARC performed aerothermal environment analyses, TPS sizing and thermal response analyses, and arc jet testing to evaluate the MER SIRCA TIRS Cover design and interface to the aeroshell structure. The primary objective of this arc jet test series was to evaluate specific design details of the SIRCA TIRS Cover interface to the MER aeroshell under simulated atmospheric entry heating conditions. Four test articles were tested in an arc jet environment with various sea] configurations. The test condition was designed to match the predicted peak flight heat load at the gap region between the SIRCA and the backshell TPS material, SLA-561S, and resulted in an over-test (with respect to heat flux and heat load) for the apex region of the SIRCA TIRS Cover. The resulting pressure differential was as much as twenty times that predicted for the flight case, depending on the location, and there was no post-test visual evidence of over-heating or damage to the seal, bracket, or backshell structure. The exposed titanium bolts were in good condition at post-test and showed only a small amount of oxidation at the leading edge locations. Repeatable thermocouple data were obtained and SIRCA thermal response analyses were compared to applicable thermocouple data. For the apex region of the SIRCA TIRS Cover, a one-dimensional thermal response prediction proved overly conservative, as there were strong multi-dimensional conduction effects evident from the thermocouple data. The one-dimensional thermal response prediction compared well with the thermocouple data for the leading edge "lip" region at the bolt location. In general, the test results yield confidence in the baseline seal design to prevent hot gas ingestion at the bracket and composite aeroshell structure interface.

Sea-ice cover in the Nordic Seas and the sensitivity to Atlantic water temperatures

NASA Astrophysics Data System (ADS)

Jensen, Mari F.; Nisancioglu, Kerim H.; Spall, Michael A.

2017-04-01

Changes in the sea-ice cover of the Nordic Seas have been proposed to play a key role for the dramatic temperature excursions associated with the Dansgaard-Oeschger events during the last glacial. However, with its proximity to the warm Atlantic water, how a sea-ice cover can persist in the Nordic Seas is not well understood. In this study, we apply an eddy-resolving configuration of the Massachusetts Institute of Technology general circulation model with an idealized topography to study the presence of sea ice in a Nordic Seas-like domain. We assume an infinite amount of warm Atlantic water present in the south by restoring the southern area to constant temperatures. The sea-surface temperatures are restored toward cold, atmospheric temperatures, and as a result, sea ice is present in the interior of the domain. However, the sea-ice cover in the margins of the Nordic Seas, an area with a warm, cyclonic boundary current, is sensitive to the amount of heat entering the domain, i.e., the restoring temperature in the south. When the temperature of the warm, cyclonic boundary current is high, the margins are free of sea ice and heat is released to the atmosphere. We show that with a small reduction in the temperature of the incoming Atlantic water, the Nordic Seas-like domain is fully covered in sea ice. Warm water is still entering the Nordic Seas, however, this happens at depths below a cold, fresh surface layer produced by melted sea ice. Consequently, the heat release to the atmosphere is reduced along with the eddy heat fluxes. Results suggest a threshold value in the amount of heat entering the Nordic Seas before the sea-ice cover disappears in the margins. We study the sensitivity of this threshold to changes in atmospheric temperatures and vertical diffusivity.

Unstructured Adaptive Meshes: Bad for Your Memory?

NASA Technical Reports Server (NTRS)

Biswas, Rupak; Feng, Hui-Yu; VanderWijngaart, Rob

2003-01-01

This viewgraph presentation explores the need for a NASA Advanced Supercomputing (NAS) parallel benchmark for problems with irregular dynamical memory access. This benchmark is important and necessary because: 1) Problems with localized error source benefit from adaptive nonuniform meshes; 2) Certain machines perform poorly on such problems; 3) Parallel implementation may provide further performance improvement but is difficult. Some examples of problems which use irregular dynamical memory access include: 1) Heat transfer problem; 2) Heat source term; 3) Spectral element method; 4) Base functions; 5) Elemental discrete equations; 6) Global discrete equations. Nonconforming Mesh and Mortar Element Method are covered in greater detail in this presentation.

Dynamic thermal signature prediction for real-time scene generation

NASA Astrophysics Data System (ADS)

Christie, Chad L.; Gouthas, Efthimios (Themie); Williams, Owen M.; Swierkowski, Leszek

2013-05-01

At DSTO, a real-time scene generation framework, VIRSuite, has been developed in recent years, within which trials data are predominantly used for modelling the radiometric properties of the simulated objects. Since in many cases the data are insufficient, a physics-based simulator capable of predicting the infrared signatures of objects and their backgrounds has been developed as a new VIRSuite module. It includes transient heat conduction within the materials, and boundary conditions that take into account the heat fluxes due to solar radiation, wind convection and radiative transfer. In this paper, an overview is presented, covering both the steady-state and transient performance.

Energy Savings Potential and Research, Development, & Demonstration Opportunities for Commercial Building Heating, Ventilation, and Air Conditioning Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

none,

2011-09-01

This report covers an assessment of 182 different heating, ventilation, and air-conditioning (HVAC) technologies for U.S. commercial buildings to identify and provide analysis on 17 priority technology options in various stages of development. The analyses include an estimation of technical energy-savings potential, description of technical maturity, description of non-energy benefits, description of current barriers for market adoption, and description of the technology’s applicability to different building or HVAC equipment types. From these technology descriptions, are suggestions for potential research, development and demonstration (RD&D) initiatives that would support further development of the priority technology options.

Mounting structure

NASA Technical Reports Server (NTRS)

Ganssle, Eugene Robert (Inventor); Scott, Ralph Richard (Inventor); Williams, Richard Jean (Inventor)

1978-01-01

A mounting platform for heat producing instruments operated in a narrow equilibrium temperature range comprises a grid-like structure with relatively large openings therein. The instruments are secured to and thermally coupled with the grid surface facing the instruments. Excess heat from the instruments is selectively radiated to the ambient through openings in the grid, the grid surfaces at these openings exhibiting low thermal emissivity and adsorptivity. The remainder of the grid is maintained at the equilibrium temperature and is covered with a thermal insulating blanket. Thus, the entire system including the platform and instruments is maintained substantially isothermal, whereby the instruments remain in fixed physical relationship to one another.

Solar thermal central receivers for industrial process heat generation: User views and recommendations for commercialization

NASA Astrophysics Data System (ADS)

Fish, M. J.

1981-08-01

Results of recent meetings with several private industrial groups in which solar thermal central receivers were discussed in depth as a potential for industrial process heat generation are summarized. Topics covering potential economics, technical requirements, and actions to promote commercialization of the technology are presented. These findings are then translated into recommendations for commercialization in private industrial markets. Key points include the need for small scale systems integration projects in addition to the 10 MW/sub e/ plant under construction at Barstow, CA, and the adoption of financial incentives, such as tax credits, for getting the early commercial plants built.

Transient and asymptotic behavior in a regular network model for the ice-albedo feedback under thermal forcing

NASA Astrophysics Data System (ADS)

Mueller-Stoffels, M.; Wackerbauer, R.

2010-12-01

The Arctic ocean and sea ice form a feedback system which plays an important role in the global climate. Variations of the global ice and snow distribution have a significant effect on the planetary albedo which governs the absorption of shortwave radiation. The complexity of highly parametrized GCMs makes it very difficult to assess single feedback processes in the climate system without the concurrent use of simple models where the physics are understood [1][2][3]. We introduce a complex systems model to investigate thermodynamic feedback processes in an Arctic ice-ocean layer. The ice-ocean layer is represented as a regular network of coupled cells. The state of each cell is determined by its energy content, which also defines the phase of the cell. The energy transport between cells is described with nonlinear and heterogeneous diffusion constants. And the time-evolution of the ice-ocean is driven by shortwave, longwave and lateral oceanic and atmospheric thermal forcing. This model is designed to study the stability of an ice cover under various heat intake scenarios. The network structure of the model allows to easily introduce albedo heterogeneities due to aging ice, wind blown snow cover, and ice movement to explore the time-evolution and pattern formation (melt ponds) processes in the Arctic sea ice. The solely thermodynamic model exhibits two stable states; one in the perennially ice covered domain and one in the perennially open water domain. Their existence is due to the temperature dependence of the longwave radiative budget. Transition between these states can be forced via lateral heat fluxes. During the transition from the ice covered to the open water stable state the ice albedo feedback effects are manifested as an increased warming rate of the ice cover together with enhanced seasonal energy oscillations. In the current model realization seasonal ice cover is present as a transient state only. Furthermore, the model exhibits hysteresis between the ice covered and the open water state when varying the lateral atmospheric (or oceanic) heat intake. Once the ice-ocean layer has transitioned from the ice covered to the open water stable state significant cooling (reduction of lateral fluxes) is necessary to return to the ice covered stable state. We also find that ocean heat fluxes are more efficient than atmospheric heat fluxes to melt Arctic sea ice; only small portions of heat entering from the bottom of the ice-ocean layer induce already a transition to the stable asymptotic state with perennial open water. This indicates that ocean currents, understood as heat conveyors, can play a significant role in melting continuous ice covers. This is consistent with the findings of Shimada et al. for the Canada basin [4]. References: [1] S. Bony et al., How well do we understand and evaluate climate change feedback processes?, J of Climate 19, 3445 (2006). [2]I. Eisenman and J.S. Wettlaufer, Nonlinear threshold behavior during the loss of Arctic sea ice, PNAS 106, 28 (2009). [3]A.S. Thorndike, A Toy Model Linking Atmospheric and Thermal Radiation and Sea Ice Growth, JGR 97, 9401 (1992). [4] K. Shimada et al., Paci[|#12#|]c Ocean inflow: Influence on catastrophic reduction of sea ice cover in the Arctic Ocean, GRL 33, L08605 (2006).

SIZE AND SURFACE AREA OF ICY DUST AGGREGATES AFTER A HEATING EVENT AT A PROTOPLANETARY NEBULA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sirono, Sin-iti

2013-03-01

The activity of a young star rises abruptly during an FU Orionis outburst. This event causes a temporary temperature increase in the protoplanetary nebula. H{sub 2}O icy grains are sublimated by this event, and silicate cores embedded inside the ice are ejected. During the high-temperature phase, the silicate grains coagulate to form silicate core aggregates. After the heating event, the temperature drops, and the ice recondenses onto the aggregates. I determined numerically the size distribution of the ice-covered aggregates. The size of the aggregates exceeds 10 {mu}m around the snow line. Because of the migration of the ice to largemore » aggregates, only a small fraction of the silicate core aggregate is covered with H{sub 2}O ice. After the heating event, the surface of an ice-covered aggregate is totally covered by silicate core aggregates. This might reduce the fragmentation velocity of aggregates when they collide. It is possible that the covering silicate cores shield the UV radiation field which induces photodissociation of H{sub 2}O ice. This effect may cause the shortage of cold H{sub 2}O vapor observed by Herschel.« less

Ontic Engineering and Manufacturing Overcharged the Defense Logistics Agency for Sole Source Spare Parts (REDACTED)

DTIC Science & Technology

2014-09-15

Motor3 ~ Total Markup 1 For 20 of the 21 parts, Ontic’s contract unit prices to DLA included royalty fees . Ontic’s contract unit price to DLA for...the Refrigeration Heat Interchanger part did not include royalty fees . 2 Minor inconsistencies in the percent differences may occur due to rounding...historical price analysis for fluid filter covers and alternating current motors was not sufficient to identifyOntic’s overcharges of royalty fees . Ontic’s

29 CFR 1915.54 - Welding, cutting and heating of hollow metal containers and structures not covered by § 1915.12.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Welding, cutting and heating of hollow metal containers and... STANDARDS FOR SHIPYARD EMPLOYMENT Welding, Cutting and Heating § 1915.54 Welding, cutting and heating of... which have contained flammable substances shall, before welding, cutting, or heating is undertaken on...

29 CFR 1915.54 - Welding, cutting and heating of hollow metal containers and structures not covered by § 1915.12.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 7 2011-07-01 2011-07-01 false Welding, cutting and heating of hollow metal containers and... STANDARDS FOR SHIPYARD EMPLOYMENT Welding, Cutting and Heating § 1915.54 Welding, cutting and heating of... which have contained flammable substances shall, before welding, cutting, or heating is undertaken on...

29 CFR 1915.54 - Welding, cutting and heating of hollow metal containers and structures not covered by § 1915.12.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 7 2012-07-01 2012-07-01 false Welding, cutting and heating of hollow metal containers and... STANDARDS FOR SHIPYARD EMPLOYMENT Welding, Cutting and Heating § 1915.54 Welding, cutting and heating of... which have contained flammable substances shall, before welding, cutting, or heating is undertaken on...

29 CFR 1915.54 - Welding, cutting and heating of hollow metal containers and structures not covered by § 1915.12.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 7 2013-07-01 2013-07-01 false Welding, cutting and heating of hollow metal containers and... STANDARDS FOR SHIPYARD EMPLOYMENT Welding, Cutting and Heating § 1915.54 Welding, cutting and heating of... which have contained flammable substances shall, before welding, cutting, or heating is undertaken on...

29 CFR 1915.54 - Welding, cutting and heating of hollow metal containers and structures not covered by § 1915.12.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 7 2014-07-01 2014-07-01 false Welding, cutting and heating of hollow metal containers and... STANDARDS FOR SHIPYARD EMPLOYMENT Welding, Cutting and Heating § 1915.54 Welding, cutting and heating of... which have contained flammable substances shall, before welding, cutting, or heating is undertaken on...

Low thermal resistance power module assembly

DOEpatents

Hassani, Vahab; Vlahinos, Andreas; Bharathan, Desikan

2007-03-13

A power module assembly with low thermal resistance and enhanced heat dissipation to a cooling medium. The assembly includes a heat sink or spreader plate with passageways or openings for coolant that extend through the plate from a lower surface to an upper surface. A circuit substrate is provided and positioned on the spreader plate to cover the coolant passageways. The circuit substrate includes a bonding layer configured to extend about the periphery of each of the coolant passageways and is made up of a substantially nonporous material. The bonding layer may be solder material which bonds to the upper surface of the plate to provide a continuous seal around the upper edge of each opening in the plate. The assembly includes power modules mounted on the circuit substrate on a surface opposite the bonding layer. The power modules are positioned over or proximal to the coolant passageways.

Solar pond

NASA Technical Reports Server (NTRS)

Miller, C. G.; Stephens, J. B. (Inventor)

1978-01-01

Shallow pools of liquid to collect low-temperature solar generated thermal energy are described. Narrow elongated trenches, grouped together over a wide area, are lined with a heat-absorbing black liner. The heat-absorbing liquid is kept separate from the thermal energy removing fluid by means such as clear polyethylene material. The covering for the pond may be a fluid or solid. If the covering is a fluid, fire fighting foam, continuously generated, or siloons are used to keep the surface covering clean and insulated. If the thermal energy removing fluid is a gas, a fluid insulation layer contained in a flat polyethlene tubing is used to cover the pond. The side of the tube directed towards the sun is treated to block out ultraviolet radiation and trap in infrared radiation.

Variation and significance of surface heat after the mechanical sand control of Qinghai-Tibet Railway was covered with sandy sediments

NASA Astrophysics Data System (ADS)

Xie, Shengbo; Qu, Jianjun; Mu, Yanhu; Xu, Xiangtian

Mechanical control of drifting sand used to protect the Qinghai-Tibet Railway from sand damage inevitably results in sand deposition, and the change in radiation and heat flux after the ground surface is covered with sandy sediments remains unclear. These variations were studied in this work through field observations along with laboratory analyses and tests. After the ground surface was covered with sandy sediments produced by the mechanical control of sand in the Qinghai-Tibet Railway, the reflectivity increased, and the annual average reflectivity on the surface covered with sandy sediments was higher than that without sandy sediments, with the value increasing by 0.043. Moreover, the surface shortwave radiation increased, whereas the surface net radiation decreased. The annual average value of the surface shortwave radiant flux density on the sandy sediments was higher than that without sandy sediments, with the value increasing by 7.291 W·m-2. The annual average value of the surface net radiant flux density on the sandy sediments decreased by 9.639 W·m-2 compared with that without sandy sediments. The soil heat flux also decreased, and the annual average value of the heat flux in the sandy sediments decreased by 0.375 W·m-2 compared with that without sandy sediments. These variations caused the heat source on the surface of sandy sediments underground to decrease, which is beneficial for preventing permafrost from degradation in the section of sand control of the railway.

Thermal-envelope field measurements in an energy-efficient office/dormitory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christian, J.E.

1982-01-01

A 345 m/sup 2/ earth-covered structure located at the Oak Ridge National Laboratory is the focus of a DOE sponsored building-envelope research project. To heat the office/dormitory building over the 1981-1982 heating season would cost $1.70/m/sup 2/ ($0.16/ft/sup 2/), assuming $0.07/kWh. The thermal-integrity factor is 0.016 kWh/m/sup 2/ /sup 0/C (2.8 Btu/ft/sup 2/ /sup 0/F). A preliminary DOE-II model estimates the monthly electric energy needs for heating within 5% of field data derived estimates. DOE-II building simulations suggest that this earth-covered/passively heated office dormitory saves 30% for space heating and 26% for cooling compared to an energy efficient above grademore » structure. A preliminary winter energy balance has been generated from data collected in February and March providing a fractional breakdown of thermal losses and gains. A number of the energy-conserving component performances have been isolated; earth-covered roof, bermed wall, and nonvented trombe wall. The earth-covered roof system showed an overall thermal transmittance of 0.18 W/m/sup 2///sup 0/C (R=31 hr ft/sup 2/ /sup 0/F/Btu). The thermocouple wells located in the earth surrounding the building indicate the additional energy savings of burying over berming. For one week in February the trombe wall produced a 50% greater net thermal gain to the building then south facing windows per equivalent unit area.« less

29 CFR 1926.354 - Welding, cutting, and heating in way of preservative coatings.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Welding, cutting, and heating in way of preservative... Welding and Cutting § 1926.354 Welding, cutting, and heating in way of preservative coatings. (a) Before welding, cutting, or heating is commenced on any surface covered by a preservative coating whose...

29 CFR 1926.354 - Welding, cutting, and heating in way of preservative coatings.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 8 2012-07-01 2012-07-01 false Welding, cutting, and heating in way of preservative... Welding and Cutting § 1926.354 Welding, cutting, and heating in way of preservative coatings. (a) Before welding, cutting, or heating is commenced on any surface covered by a preservative coating whose...

29 CFR 1926.354 - Welding, cutting, and heating in way of preservative coatings.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 8 2014-07-01 2014-07-01 false Welding, cutting, and heating in way of preservative... Welding and Cutting § 1926.354 Welding, cutting, and heating in way of preservative coatings. (a) Before welding, cutting, or heating is commenced on any surface covered by a preservative coating whose...

29 CFR 1926.354 - Welding, cutting, and heating in way of preservative coatings.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 8 2011-07-01 2011-07-01 false Welding, cutting, and heating in way of preservative... Welding and Cutting § 1926.354 Welding, cutting, and heating in way of preservative coatings. (a) Before welding, cutting, or heating is commenced on any surface covered by a preservative coating whose...

29 CFR 1926.354 - Welding, cutting, and heating in way of preservative coatings.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 8 2013-07-01 2013-07-01 false Welding, cutting, and heating in way of preservative... Welding and Cutting § 1926.354 Welding, cutting, and heating in way of preservative coatings. (a) Before welding, cutting, or heating is commenced on any surface covered by a preservative coating whose...

Estimation of genetic parameters for heat stress, including dominance gene effects, on milk yield in Thai Holstein dairy cattle.

PubMed

Boonkum, Wuttigrai; Duangjinda, Monchai

2015-03-01

Heat stress in tropical regions is a major cause that strongly negatively affects to milk production in dairy cattle. Genetic selection for dairy heat tolerance is powerful technique to improve genetic performance. Therefore, the current study aimed to estimate genetic parameters and investigate the threshold point of heat stress for milk yield. Data included 52 701 test-day milk yield records for the first parity from 6247 Thai Holstein dairy cattle, covering the period 1990 to 2007. The random regression test day model with EM-REML was used to estimate variance components, genetic parameters and milk production loss. A decline in milk production was found when temperature and humidity index (THI) exceeded a threshold of 74, also it was associated with the high percentage of Holstein genetics. All variance component estimates increased with THI. The estimate of heritability of test-day milk yield was 0.231. Dominance variance as a proportion to additive variance (0.035) indicated that non-additive effects might not be of concern for milk genetics studies in Thai Holstein cattle. Correlations between genetic and permanent environmental effects, for regular conditions and due to heat stress, were - 0.223 and - 0.521, respectively. The heritability and genetic correlations from this study show that simultaneous selection for milk production and heat tolerance is possible. © 2014 Japanese Society of Animal Science.

Thermal Technology Development Activities at the Goddard Space Flight Center - 2001

NASA Technical Reports Server (NTRS)

Butler, Dan

2002-01-01

This presentation provides an overview of thermal technology development activities carried out at NASA's Goddard Space Flight Center during 2001. Specific topics covered include: two-phase systems (heat pipes, capillary pumped loops, vapor compression systems and phase change materials), variable emittance systems, advanced coatings, high conductivity materials and electrohydrodynamic (EHD) thermal coatings. The application of these activities to specific space missions is also discussed.

New textile composite materials development, production, application

NASA Technical Reports Server (NTRS)

Mikhailov, Petr Y.

1993-01-01

New textile composite materials development, production, and application are discussed. Topics covered include: super-high-strength, super-high-modulus fibers, filaments, and materials manufactured on their basis; heat-resistant and nonflammable fibers, filaments, and textile fabrics; fibers and textile fabrics based on fluorocarbon poylmers; antifriction textile fabrics based on polyfen filaments; development of new types of textile combines and composite materials; and carbon filament-based fabrics.

RTO Technical Publications: A Quarterly Listing

NASA Technical Reports Server (NTRS)

2004-01-01

This is a listing of recent unclassified RTO technical publications for April 1, 2004 through June 30, 2004, processed by the NASA Center for AeroSpace Information. Topics covered include: heat transfer and cooling in propulsion and power systems; assessment of operator functional state; microwaves; aerodynamics in solid rocket propulsion; command, control, communications and intelligence modeling; personal protective equipment against anti-personnel mine blast; and data fusion and visualization.

Evaluation of an urban canopy model in a tropical city: the role of tree evapotranspiration

NASA Astrophysics Data System (ADS)

Liu, Xuan; Li, Xian-Xiang; Harshan, Suraj; Roth, Matthias; Velasco, Erik

2017-09-01

A single layer urban canopy model (SLUCM) with enhanced hydrologic processes, is evaluated in a tropical city, Singapore. The evaluation was performed using an 11 month offline simulation with the coupled Noah land surface model/SLUCM over a compact low-rise residential area. Various hydrological processes are considered, including anthropogenic latent heat release, and evaporation from impervious urban facets. Results show that the prediction of energy fluxes, in particular latent heat flux, is improved when these processes were included. However, the simulated latent heat flux is still underestimated by ∼40%. Considering Singapore’s high green cover ratio, the tree evapotranspiration process is introduced into the model, which significantly improves the simulated latent heat flux. In particular, the systematic error of the model is greatly reduced, and becomes lower than the unsystematic error in some seasons. The effect of tree evapotranspiration on the urban surface energy balance is further demonstrated during an unusual dry spell. The present study demonstrates that even at sites with relatively low (11%) tree coverage, ignoring evapotranspiration from trees may cause serious underestimation of the latent heat flux and atmospheric humidity. The improved model is also transferable to other tropical or temperate regions to study the impact of tree evapotranspiration on urban climate.

Methods Used in EnviroAtlas to Assess Urban Natural ...

EPA Pesticide Factsheets

Previous studies have positively correlated human exposures to natural features with health promoting outcomes such as increased physical activity, improved cognitive function, increased social engagement, and reduced ambient air pollution. When using remotely-sensed data to investigate these relationships, researchers must first identify an appropriate spatial resolution to characterize exposures. However, metric development has often been limited by the lack of fine-scale land cover data, especially across multiple communities. As a result, researchers commonly use coarse resolution imagery. EnviroAtlas, a U.S. Environmental Protection Agency web-based ecosystem services mapping tool, has developed 1-meter resolution land cover data across 16 diverse U.S. Census Urban Areas using aerial photography and supplemental data. Research maps derived from these foundational data include percent tree cover along busy roads, percent tree cover and green space along walkable streets, and percent natural vegetation bordering water bodies. EnviroAtlas has also developed multiple smoothed “heat maps” of proximity to specific types of features at every 1m point; these include total green space, tree cover, and water within 50m, 500m, and 1,000m buffers; walking distance to the nearest park entrance; and intersection density as an indicator of neighborhood walkability.EnviroAtlas variables are available to external researchers, public health professionals and planners t

New Approach for Thermal Protection System of a Probe During Entry

NASA Technical Reports Server (NTRS)

Yendler, Boris; Poffenbarger, Nathan; Patel, Amisha; Bhave, Ninad; Papadopoulos, Periklis

2005-01-01

One of the biggest challenges for any thermal protection system (TPS) of a probe is to provide a sufficient barrier for heat generated during descent in order to keep the temperature inside of the probe low enough to support operational temperature of equipment. Typically, such a goal is achieved by having the ceramic tiles and blankets like on the Space Shuttle, silicon based ablators, or metallic systems to cover the probe external surface. This paper discusses the development of an innovative technique for TPS of the probe. It is proposed to use a novel TPS which comprises thermal management of the entry vehicle. It includes: a) absorption of the heat during heat pick load by a Phase Change Material (PCM), b) separation of the compartment which contains PCM from the rest of the space vehicle by a gap with a high thermal resistance, c) maintaining temperature of the internal wall of s/c cabin temperature by transfer heat from the internal wall to the "cold" side of the vehicle and to reject heat into the space during the flight and on a ground, d) utilization of an advanced heat pipe, so called Loop Heat Pipe to transfer heat from the cabin internal wall to the cold side of the s/c and to reject the heat into environment outside of the vehicle. A Loop Heat Pipe is capable of transferring heat against gravity

Hydromechanics and heat and mass exchange in weightlessness (Russian book): Table of contents

NASA Technical Reports Server (NTRS)

Avduyevskiy, V. S.; Poleshayev, V. I.

1983-01-01

The table of contents is given for a book on hydromechanics and heat and mass exchange in weightlessness. The book covers such subjects as hydromechanics, convection and heat and mass exchange, and technological experiments and complicated systems.

Surface-restrained growth of vertically aligned carbon nanotube arrays with excellent thermal transport performance.

PubMed

Ping, Linquan; Hou, Peng-Xiang; Liu, Chang; Li, Jincheng; Zhao, Yang; Zhang, Feng; Ma, Chaoqun; Tai, Kaiping; Cong, Hongtao; Cheng, Hui-Ming

2017-06-22

A vertically aligned carbon nanotube (VACNT) array is a promising candidate for a high-performance thermal interface material in high-power microprocessors due to its excellent thermal transport property. However, its rough and entangled free tips always cause poor interfacial contact, which results in serious contact resistance dominating the total thermal resistance. Here, we employed a thin carbon cover to restrain the disorderly growth of the free tips of a VACNT array. As a result, all the free tips are seamlessly connected by this thin carbon cover and the top surface of the array is smoothed. This unique structure guarantees the participation of all the carbon nanotubes in the array in the heat transport. Consequently the VACNT array grown on a Cu substrate shows a record low thermal resistance of 0.8 mm 2 K W -1 including the two-sided contact resistances, which is 4 times lower than the best result previously reported. Remarkably, the VACNT array can be easily peeled away from the Cu substrate and act as a thermal pad with excellent flexibility, adhesive ability and heat transport capability. As a result the CNT array with a thin carbon cover shows great potential for use as a high-performance flexible thermal interface material.

Projected Impact of Climate Change on the Energy Budget of the Arctic Ocean by a Global Climate Model

NASA Technical Reports Server (NTRS)

Miller, James R.; Russell, Gary L.; Hansen, James E. (Technical Monitor)

2001-01-01

The annual energy budget of the Arctic Ocean is characterized by a net heat loss at the air-sea interface that is balanced by oceanic heat transport into the Arctic. The energy loss at the air-sea interface is due to the combined effects of radiative, sensible, and latent heat fluxes. The inflow of heat by the ocean can be divided into two components: the transport of water masses of different temperatures between the Arctic and the Atlantic and Pacific Oceans and the export of sea ice, primarily through Fram Strait. Two 150-year simulations (1950-2099) of a global climate model are used to examine how this balance might change if atmospheric greenhouse gases (GHGs) increase. One is a control simulation for the present climate with constant 1950 atmospheric composition, and the other is a transient experiment with observed GHGs from 1950 to 1990 and 0.5% annual compounded increases of CO2 after 1990. For the present climate the model agrees well with observations of radiative fluxes at the top of the atmosphere, atmospheric advective energy transport into the Arctic, and surface air temperature. It also simulates the seasonal cycle and summer increase of cloud cover and the seasonal cycle of sea-ice cover. In addition, the changes in high-latitude surface air temperature and sea-ice cover in the GHG experiment are consistent with observed changes during the last 40 and 20 years, respectively. Relative to the control, the last 50-year period of the GHG experiment indicates that even though the net annual incident solar radiation at the surface decreases by 4.6 W(per square meters) (because of greater cloud cover and increased cloud optical depth), the absorbed solar radiation increases by 2.8 W(per square meters) (because of less sea ice). Increased cloud cover and warmer air also cause increased downward thermal radiation at the surface so that the net radiation into the ocean increases by 5.0 Wm-2. The annual increase in radiation into the ocean, however, is compensated by larger increases in sensible and latent heat fluxes out of the ocean. Although the net energy loss from the ocean surface increases by 0.8 W (per square meters), this is less than the interannual variability, and the increase may not indicate a long-term trend. The seasonal cycle of heat fluxes is significantly enhanced. The downward surface heat flux increases in summer (maximum 2 of 19 W per square meters or 23% in June) while the upward heat flux increases in winter (maximum of 16 W per square meters or 28% in November). The increased downward flux in summer is due to a combination of increases in absorbed solar and thermal radiation and smaller losses of sensible and latent heat. The increased heat loss in winter is due to increased sensible and latent heat fluxes, which in turn are due to reduced sea-ice cover. On the other hand, the seasonal cycle of surface air temperature is damped, as there is a large increase in winter temperature but little change in summer.

Effect of ploidy on scale-cover pattern in linear ornamental (koi) common carp Cyprinus carpio.

PubMed

Gomelsky, B; Schneider, K J; Glennon, R P; Plouffe, D A

2012-09-01

The effect of ploidy on scale-cover pattern in linear ornamental (koi) common carp Cyprinus carpio was investigated. To obtain diploid and triploid linear fish, eggs taken from a leather C. carpio female (genotype ssNn) and sperm taken from a scaled C. carpio male (genotype SSnn) were used for the production of control (no shock) and heat-shocked progeny. In heat-shocked progeny, the 2 min heat shock (40° C) was applied 6 min after insemination. Diploid linear fish (genotype SsNn) demonstrated a scale-cover pattern typical for this category with one even row of scales along lateral line and few scales located near operculum and at bases of fins. The majority (97%) of triploid linear fish (genotype SssNnn) exhibited non-typical scale patterns which were characterized by the appearance of additional scales on the body. The extent of additional scales in triploid linear fish was variable; some fish had large scales, which covered almost the entire body. Apparently, the observed difference in scale-cover pattern between triploid and diploid linear fish was caused by different phenotypic expression of gene N/n. Due to incomplete dominance of allele N, triploids Nnn demonstrate less profound reduction of scale cover compared with diploids Nn. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Method and apparatus for extracting tritium and preparing radioactive waste for disposal

DOEpatents

Heung, Leung K.

1994-01-01

Apparatus for heating an object such as a nuclear target bundle to release and recover hydrogen and contain the disposable residue for disposal. The apparatus comprises an inverted furnace, a sleeve/crucible assembly for holding and enclosing the bundle, conveying equipment for placing the sleeve onto the crucible and loading the bundle into the sleeve/crucible, a lift for raising the enclosed bundle into the furnace, and hydrogen recovery equipment including a trap and strippers, all housed in a containment having negative internal pressure. The crucible/sleeve assembly has an internal volume that is sufficient to enclose and hold the bundle before heating; the crucible's internal volume is sufficient by itself to hold and enclose the bundle's volume after heating. The crucible can then be covered and disposed of; the sleeve, on the other hand, can be reused.

Precision heat forming of tetrafluoroethylene tubing

NASA Technical Reports Server (NTRS)

Ruiz, W. V.; Thatcher, C. S. (Inventor)

1981-01-01

An invention that provides a method of altering the size of tetrafluoroethylene tubing which is only available in limited combination of wall thicknesses and diameter are discussed. The method includes the steps of sliding the tetrafluoroethylene tubing onto an aluminum mandrel and clamping the ends of the tubing to the mandrel by means of clamps. The tetrafluorethylene tubing and mandrel are then placed in a supporting coil which with the mandrel and tetrafluorethylene tubing are then positioned in a insulated steel pipe which is normally covered with a fiber glass insulator to smooth out temperature distribution therein. The entire structure is then placed in an event which heats the tetrafluorethylene tubing which is then shrunk by the heat to the outer dimension of the aluminum mandrel. After cooling the aluminum mandrel is removed from the newly sized tetrafluorethylene tubing by a conventional chemical milling process.

Advances in refrigeration and heat transfer engineering

DOE PAGES

Bansal, Pradeep; Cremaschi, Prof. Lorenzo

2015-05-13

This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO 2 may perhaps have beenmore » the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).« less

Advances in refrigeration and heat transfer engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Pradeep; Cremaschi, Prof. Lorenzo

This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO 2 may perhaps have beenmore » the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).« less

Study of magnetic notions in the solar photosphere and their implications for heating the solar atmosphere

NASA Technical Reports Server (NTRS)

Noyes, Robert W.

1995-01-01

This progress report covers the first year of NASA Grant NAGw-2545, a study of magnetic structure in the solar photosphere and chromosphere. We have made significant progress in three areas: (1) analysis of vorticity in photospheric convection, which probably affects solar atmospheric heating through the stresses it imposes on photospheric magnetic fields; (2) modelling of the horizontal motions of magnetic footpoints in the solar photosphere using an assumed relation between brightness and vertical motion as well as continuity of flow; and (3) observations and analysis of infrared CO lines formed near the solar temperature minimum, whose structure and dynamics also yield important clues to the nature of heating of the upper atmosphere. Each of these areas are summarized in this report, with copies of those papers prepared or published this year included.

Review of subcooled flow boiling critical heat flux (CHF) and its application to fusion energy system components part II: microconvective, experimental and correlational aspects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyd, R.D.

This paper reviews the present understanding of critical heat flux (CHF) in subcooled flow boiling and outlines research directions which will permit the accommodation of higher heat fluxes. This survey, which covers the last 30 years, is concerned only with CHF in the subcooled flow boiling regime and unless otherwise noted, all references to CHF will be confined to that regime. This paper (Part II) summarizes microconvective, instability, experimental and correlational aspects of CHF. Section II covers microconvection and instabilities, section III covers representative experimental work, and section IV summarizes and compares selected CHF correlations. Section V documents previous flowmore » visualization work and section VI contains conclusions and recommendations concerning problem areas and suggested research directions essential to the HHFCDP, which involves extending steady state and transient CHF towards 30 kW/cm/sup 2/.« less

Solar Energy School Heating Augmentation Experiment. Sections I, II, and III.

ERIC Educational Resources Information Center

InterTechnology Corp., Warrenton, VA.

An experimental solar heating system heats five modular classrooms at the Fauquier County High School in Warrenton, Virginia. The present report covers the operation, maintenance, and modifications to the system over the 1974-75 and 1975-76 heating seasons. The solar system has shown the capability of providing essentially 100 percent of the…

Balancing the Energy Pendulum.

ERIC Educational Resources Information Center

MacKinnon, Sharon

1987-01-01

The city of Kitchener, Ontario, has installed a heat recovery loop in one indoor pool, all indoor swimming pools use pool covers, and two have solar heating. Energy is saved in two ice arenas by low-emissivity ceilings, and in the largest arena by a heat recovery system. (MLF)

Solar power plant and still

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, W.P.

This patent describes a solar energy system. It comprises: a water pond which is heated by solar energy; a cover above the pond which transmits solar energy; an air space between the pond and the cover through which warm air and vaporized water move; a chimney which induces the rapid flow of warm humid air into its lower end and delivers such air at its upper end; a fresh water heat sink which receives condensed vapor from the chimney-induced flow; a heat energy driven engine, the power output of which is a function of the temperature difference between higher andmore » lower temperature levels; a first heat exchanger in the engine connected to the top of the chimney, and arranged to convert the vapor condensation energy into the higher temperature level of th engine; a second heat exchanger in the engine arranged to provide the lower temperature of the engine by connection to the heat sink; and power transfer means driven by the temperature differential energy of the engine.« less

The Effect of Seasonal Variability of Atlantic Water on the Arctic Sea Ice Cover

NASA Astrophysics Data System (ADS)

Ivanov, V. V.; Repina, I. A.

2018-01-01

Under the influence of global warming, the sea ice in the Arctic Ocean (AO) is expected to reduce with a transition toward a seasonal ice cover by the end of this century. A comparison of climate-model predictions with measurements shows that the actual rate of ice cover decay in the AO is higher than the predicted one. This paper argues that the rapid shrinking of the Arctic summer ice cover is due to its increased seasonality, while seasonal oscillations of the Atlantic origin water temperature create favorable conditions for the formation of negative anomalies in the ice-cover area in winter. The basis for this hypothesis is the fundamental possibility of the activation of positive feedback provided by a specific feature of the seasonal cycle of the inflowing Atlantic origin water and the peaking of temperature in the Nansen Basin in midwinter. The recently accelerated reduction in the summer ice cover in the AO leads to an increased accumulation of heat in the upper ocean layer during the summer season. The extra heat content of the upper ocean layer favors prerequisite conditions for winter thermohaline convection and the transfer of heat from the Atlantic water (AW) layer to the ice cover. This, in turn, contributes to further ice thinning and a decrease in ice concentration, accelerated melting in summer, and a greater accumulation of heat in the ocean by the end of the following summer. An important role is played by the seasonal variability of the temperature of AW, which forms on the border between the North European and Arctic basins. The phase of seasonal oscillation changes while the AW is moving through the Nansen Basin. As a result, the timing of temperature peak shifts from summer to winter, additionally contributing to enhanced ice melting in winter. The formulated theoretical concept is substantiated by a simplified mathematical model and comparison with observations.

Instantaneous and daily values of the surface energy balance over agricultural fields using remote sensing and a reference field in an arid environment

USGS Publications Warehouse

Kustas, William P.; Moran, M.S.; Jackson, R. D.; Gay, L.W.; Duell, L.F.W.; Kunkel, K.E.; Matthias, A.D.

1990-01-01

Remotely sensed surface temperature and reflectance in the visible and near infrared wavebands along with ancilliary meteorological data provide the capability of computing three of the four surface energy balance components (i.e., net radiation, soil heat flux, and sensible heat flux) at different spatial and temporal scales. As a result, under nonadvective conditions, this enables the estimation of the remaining term (i.e., the latent heat flux). One of the practical applications with this approach is to produce evapotranspiration (ET) maps for agricultural regions which consist of an array of fields containing different crops at varying stages of growth and soil moisture conditions. Such a situation exists in the semiarid southwest at the University of Arizona Maricopa Agricultural Center, south of Phoenix. For one day (14 June 1987), surface temperature and reflectance measurements from an aircraft 150 m above ground level (agl) were acquired over fields from zero to nearly full cover at four times between 1000 MST and 1130 MST. The diurnal pattern of the surface energy balance was measured over four fields, which included alfalfa at 60% cover, furrowed cotton at 20% and 30% cover, and partially plowed what stubble. Instantaneous and daily values of ET were estimated for a representative area around each flux site with an energy balance model that relies on a reference ET. This reference value was determined with remotely sensed data and several meteorological inputs. The reference ET was adjusted to account for the different surface conditions in the other fields using only remotely sensed variables. A comparison with the flux measurements suggests the model has difficulties with partial canopy conditions, especially related to the estimation of the sensible heat flux. The resulting errors for instantaneous ET were on the order of 100 W m-2 and for daily values of order 2 mm day-1. These findings suggest future research should involve development of methods to account for the variability of meteorological parameters brought about by changes in surface conditions and improvements in the modeling of sensible heat transfer across the surface-atmosphere interface for partial canopy conditions using remote sensing information. ?? 1990.

Modelling The Energy And Mass Balance Of A Black Glacier

NASA Astrophysics Data System (ADS)

Grossi, G.; Taschner, S.; Ranzi, R.

A distributed energy balance hydrologic model has been implemented to simulate the melting season of the Belvedere glacier, situated in the Anza river basin (North- Western Italy) for a few years. The Belvedere Glacier is an example of SblackS glacier, ´ since the ablation zone is covered by a significant debris layer. The glacierSs termi- nus has an altitude of 1785 m asl which is very unusual for the Southern side of the European Alps. The model accounts for the energy exchange processes at the inter- face between the atmospheric boundary layer and the snow/ice/debris layer. To run the model hydrometeorological and physiographic data were collected, including the depth of the debris cover and the tritium (3H) concentration in the glacial river. Mea- surements of the soil thermal conductivity were carried out during a field campaign organised within the glaciers monitoring GLIMS project, at the time of the passage of the Landsat and the Terra satellites last 15 August 2001. A comparison of the different energy terms simulated by the model assigns a dominant role to the shortwave radia- tion, which provides the highest positive contribution to the energy available for snow- and ice-melt, while the sensible heat turns out to be the second major source of heat. Longwave radiation balance and latent heat seem to be less relevant and often nega- tive. The role of the debris cover is not negligible, since its thermal insulation causes, on average, a decrease in the ice melt volume. One of the model variables is the tem- perature of the debris cover, which can be a useful information when a black glacier is to be monitored through remote sensing techniques. The visible and near infrared radi- ation data do not always provide sufficient information to detect the glaciers' margins beneath the debris layer. For this reason the information of the different thermal sur- face characteristics (pure ice, debris covered ice, rock), proved by the energy balance model results was applied for the glacierSs classification with a Landsat-TM image. Taking into account also the thermal infrared band leads to an improved classification result.

Mathematical modeling of high and low temperature heat pipes

NASA Technical Reports Server (NTRS)

Chi, S. W.

1971-01-01

Mathematical models are developed for calculating heat-transfer limitations of high-temperature heat pipes and heat-transfer limitations and temperature gradient of low temperature heat pipes. Calculated results are compared with the available experimental data from various sources to increase confidence in the present math models. Complete listings of two computer programs for high- and low-temperature heat pipes respectively are appended. These programs enable the performance of heat pipes with wrapped-screen, rectangular-groove or screen-covered rectangular-groove wick to be predicted.

MODIS land cover uncertainty in regional climate simulations

NASA Astrophysics Data System (ADS)

Li, Xue; Messina, Joseph P.; Moore, Nathan J.; Fan, Peilei; Shortridge, Ashton M.

2017-12-01

MODIS land cover datasets are used extensively across the climate modeling community, but inherent uncertainties and associated propagating impacts are rarely discussed. This paper modeled uncertainties embedded within the annual MODIS Land Cover Type (MCD12Q1) products and propagated these uncertainties through the Regional Atmospheric Modeling System (RAMS). First, land cover uncertainties were modeled using pixel-based trajectory analyses from a time series of MCD12Q1 for Urumqi, China. Second, alternative land cover maps were produced based on these categorical uncertainties and passed into RAMS. Finally, simulations from RAMS were analyzed temporally and spatially to reveal impacts. Our study found that MCD12Q1 struggles to discriminate between grasslands and croplands or grasslands and barren in this study area. Such categorical uncertainties have significant impacts on regional climate model outputs. All climate variables examined demonstrated impact across the various regions, with latent heat flux affected most with a magnitude of 4.32 W/m2 in domain average. Impacted areas were spatially connected to locations of greater land cover uncertainty. Both biophysical characteristics and soil moisture settings in regard to land cover types contribute to the variations among simulations. These results indicate that formal land cover uncertainty analysis should be included in MCD12Q1-fed climate modeling as a routine procedure.

Urban heat island effect: A systematic review of spatio-temporal factors, data, methods, and mitigation measures

NASA Astrophysics Data System (ADS)

Deilami, Kaveh; Kamruzzaman, Md.; Liu, Yan

2018-05-01

Despite research on urban heat island (UHI) effect has increased exponentially over the last few decades, a systematic review of factors contributing to UHI effect has scarcely been reported in the literature. This paper provides a systematic and overarching review of different spatial and temporal factors affecting the UHI effect. UHI is a phenomenon when urban areas experience a higher temperature than their surrounding non-urban areas and is considered as a critical factor contributing to global warming, heat related mortalities, and unpredictable climatic changes. Therefore, there is a pressing need to identify the spatio-temporal factors that contribute to (or mitigate) the UHI effect in order to develop a thorough understanding of their causal mechanism so that these are addressed through urban planning policies. This paper systematically identified 75 eligible studies on UHI effect and reviews the nature and type of satellite images used, the techniques applied to classify land cover/use changes, the models to assess the link between spatio-temporal factors and UHI effect, and the effects of these factors on UHI. The review results show that: a) 54% of the studies used Landsat TM images for modelling the UHI effect followed by Landsat ETM (34%), and MODIS (28%); b) land cover indices (46%), followed by supervised classification (17%) were the dominant methods to derive land cover/use changes associated with UHI effect; c) ordinary least square regression is the most commonly applied method (68%) to investigate the link between different spatio-temporal factors and the UHI effect followed by comparative analysis (33%); and d) the most common factors affecting the UHI effect as reported in the reviewed studies, include vegetation cover (44%), season (33%), built-up area (28%), day/night (25%), population density (14%), water body (12%) together with others. This research discusses the findings in policy terms and provides directions for future research.

Multicompartment Liquid-Cooling/Warming Protective Garments

NASA Technical Reports Server (NTRS)

Koscheyev, Victor S.; Leon, Gloria R.; Dancisak, Michael J.

2005-01-01

Shortened, multicompartment liquid-cooling / warming garments (LCWGs) for protecting astronauts, firefighters, and others at risk of exposure to extremes of temperature are undergoing development. Unlike prior liquid-circulation thermal-protection suits that provide either cooling or warming but not both, an LCWG as envisioned would provide cooling at some body locations and/or heating at other locations, as needed: For example, sometimes there is a need to cool the body core and to heat the extremities simultaneously. An LCWG garment of the type to be developed is said to be shortened because the liquid-cooling and - heating zones would not cover the whole body and, instead, would cover reduced areas selected for maximum heating and cooling effectiveness. Physiological research is under way to provide a rational basis for selection of the liquid-cooling and -heating areas. In addition to enabling better (relative to prior liquid-circulation garments) balancing of heat among different body regions, the use of selective heating and cooling in zones would contribute to a reduction in the amount of energy needed to operate a thermal-protection suit.

Fundamentals of Solar Heating. Correspondence Course.

ERIC Educational Resources Information Center

Sheet Metal and Air Conditioning Contractors National Association, Vienna, VA.

This course is designed for the use of employees of the air conditioning industry, and offers supervised correspondence instruction about solar technology. The following aspects of applied solar technology are covered: solar heating and cooling, solar radiation, solar collectors, heat storage control devices and specialty items, sizing solar…

Stable "Waterbelt" climates controlled by tropical ocean heat transport: A nonlinear coupled climate mechanism of relevance to Snowball Earth

NASA Astrophysics Data System (ADS)

Rose, Brian E. J.

2015-02-01

Ongoing controversy about Neoproterozoic Snowball Earth events motivates a theoretical study of stability and hysteresis properties of very cold climates. A coupled atmosphere-ocean-sea ice general circulation model (GCM) has four stable equilibria ranging from 0% to 100% ice cover, including a "Waterbelt" state with tropical sea ice. All four states are found at present-day insolation and greenhouse gas levels and with two idealized ocean basin configurations. The Waterbelt is stabilized against albedo feedback by intense but narrow wind-driven ocean overturning cells that deliver roughly 100 W m-2 heating to the ice edges. This requires three-way feedback between winds, ocean circulation, and ice extent in which circulation is shifted equatorward, following the baroclinicity at the ice margins. The thermocline is much shallower and outcrops in the tropics. Sea ice is snow-covered everywhere and has a minuscule seasonal cycle. The Waterbelt state spans a 46 W m-2 range in solar constant, has a significant hysteresis, and permits near-freezing equatorial surface temperatures. Additional context is provided by a slab ocean GCM and a diffusive energy balance model, both with prescribed ocean heat transport (OHT). Unlike the fully coupled model, these support no more than one stable ice margin, the position of which is slaved to regions of rapid poleward decrease in OHT convergence. Wide ranges of different climates (including the stable Waterbelt) are found by varying the magnitude and spatial structure of OHT in both models. Some thermodynamic arguments for the sensitivity of climate, and ice extent to OHT are presented.

Theory of stability, and regulation and control of ecological system in oasis

NASA Astrophysics Data System (ADS)

Pan, Xiaoling; Chao, Jiping

2003-06-01

Starting with analysis on the evolving course of oasis and the characteristics and evolution of transitional zone between oasis and desert, in consideration of ecological elements including plant stomata resistance, area covered by vegetation, and physical elements including albedo of vegetation and bare soil, atmosphere temperature, and humidity, under the condition of the balance among net radiation flux, latent heat flux, and sensible heat flux, the following are calculated: temperatures of vegetation and bare soil in different conditions, as well as the evapotranspiration rate of ecosystem. Analysis on evapotranspiration rate indicates that it depends on both the climate of environment and the physiological and ecological conditions of plants. On certain conditions, the evapotranspiration rate of transitional zone between oasis and desert (i.e. area covered by vegetation less than 20%), in some parameter domains, appears in bifurcation or multiequilibrium state. Meanwhile, in such area, ecosystem is extremely unstable. Any minor change to the balance will cause either increase or reduction of area covered by vegetation in ecosystem, on the basis of discussion on the emergency of these phenomena. This paper is attempting to propose an effective way of destruction and rebuilt ecosystem in transitional zone. The way is to control the evaporation of plant through selecting anti-drought country plant with big stomata resistance, and modify the roughness of the underlying surface in ecosystem by establishing rational interspace structure of plant community, so as to put the degenerative ecosystem into the natural succession track. This primary theory is being verified through observation and analysis on historical data.

Process gas hear recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, W.M.; Thurner, R.P.

1977-01-01

In considering the use of regenerative and recuperative heat exchangers for process-gas heat recovery general information regarding heat-exchanger effectiveness versus initial capital investment and operating costs is discussed. Specific examples for preheating combustion air for process furnaces and for using primary and secondary heat exchangers in conjunction with an air-pollution-control system for drying and curing ovens cover basic heat-exchanger design and application considerations as well as investment-payback factors.

Data use investigations for applications Explorer Mission A (Heat Capacity Mapping Mission): HCMM's role in studies of the urban heat island, Great Lakes thermal phenomena and radiometric calibration of satellite data. [Buffalo, Syracuse, and Rochester New York and Lake Ontario

NASA Technical Reports Server (NTRS)

Schott, J. R. (Principal Investigator); Schimminger, E. W.

1981-01-01

The utility of data from NASA'a heat capacity mapping mission satellite for studies of the urban heat island, thermal phenomena in large lakes and radiometric calibration of satellite sensors was assessed. The data were found to be of significant value in all cases. Using HCMM data, the existence and microstructure of the heat island can be observed and associated with land cover within the urban complex. The formation and development of the thermal bar in the Great Lakes can be observed and quantitatively mapped using HCMM data. In addition, the thermal patterns observed can be associated with water quality variations observed both from other remote sensing platforms and in situ. The imaging radiometer on-board the HCMM satellite is shown to be calibratible to within about 1.1 C of actual surface temperatures. These findings, as well as the analytical procedures used in studying the HCMM data, are included.

Analysis of the Intra-City Variation of Urban Heat Island and its Relation to Land Surface/cover Parameters

NASA Astrophysics Data System (ADS)

Gerçek, D.; Güven, İ. T.; Oktay, İ. Ç.

2016-06-01

Along with urbanization, sealing of vegetated land and evaporation surfaces by impermeable materials, lead to changes in urban climate. This phenomenon is observed as temperatures several degrees higher in densely urbanized areas compared to the rural land at the urban fringe particularly at nights, so-called Urban Heat Island. Urban Heat Island (UHI) effect is related with urban form, pattern and building materials so far as it is associated with meteorological conditions, air pollution, excess heat from cooling. UHI effect has negative influences on human health, as well as other environmental problems such as higher energy demand, air pollution, and water shortage. Urban Heat Island (UHI) effect has long been studied by observations of air temperature from thermometers. However, with the advent and proliferation of remote sensing technology, synoptic coverage and better representations of spatial variation of surface temperature became possible. This has opened new avenues for the observation capabilities and research of UHIs. In this study, "UHI effect and its relation to factors that cause it" is explored for İzmit city which has been subject to excess urbanization and industrialization during the past decades. Spatial distribution and variation of UHI effect in İzmit is analysed using Landsat 8 and ASTER day & night images of 2015 summer. Surface temperature data derived from thermal bands of the images were analysed for UHI effect. Higher temperatures were classified into 4 grades of UHIs and mapped both for day and night. Inadequate urban form, pattern, density, high buildings and paved surfaces at the expanse of soil ground and vegetation cover are the main factors that cause microclimates giving rise to spatial variations in temperatures across cities. These factors quantified as land surface/cover parameters for the study include vegetation index (NDVI), imperviousness (NDISI), albedo, solar insolation, Sky View Factor (SVF), building envelope, distance to sea, and traffic space density. These parameters that cause variation in intra-city temperatures were evaluated for their relationship with different grades of UHIs. Zonal statistics of UHI classes and variations in average value of parameters were interpreted. The outcomes that highlight local temperature peaks are proposed to the attention of the decision makers for mitigation of Urban Heat Island effect in the city at local and neighbourhood scale.

Modification of the continuous flow diffusion chamber for use in zero-gravity. [atmospheric cloud physics lab

NASA Technical Reports Server (NTRS)

Keyser, G.

1978-01-01

The design philosophy and performance characteristics of the continuous flow diffusion chamber developed for use in ground-based simulation of some of the experiments planned for the atmospheric cloud physics laboratory during the first Spacelab flight are discussed. Topics covered include principle of operation, thermal control, temperature measurement, tem-powered heat exchangers, wettable metal surfaces, sample injection system, and control electronics.

Thermal Barrier Coating Workshop, 1997

NASA Technical Reports Server (NTRS)

Brindley, William J. (Compiler)

1998-01-01

This document contains papers from the 1997 Thermal Barrier Coatings Workshop, sponsored by the TBC Interagency Coordination Committee. The Workshop was held in Fort Mitchell, Kentucky, May 19-21, 1997. The papers cover the topics of heat transfer and conductivity of thermal barrier coatings, failure mechanisms and characterization of the coatings as well as characterization of coating deposition methods. Speakers included research, development and user groups in academia, industry and government.

Sealing ducts to save energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siuru, B.

1996-07-01

Large amounts of energy are wasted when heat leaks through ductwork located in uninsulated spaces. The Electric Power Research INstitute recently did a study that accurately measured these losses, then substantially reduced them by sealing the leaky ductwork. Six homes in the Pacific Northwest with significant duct leakage to the outside were selected for the study. The homes had electric resistance or heat pump, forced-air heating systems with a major portion of the supply and return ductwork in crawl spaces, attics, garages, etc. Measurements of duct leakage and heating system efficiency were done on all the homes before starting themore » duct sealing. Retrofitting included finding holes, gaps, cracks and disconnected joints in supply and return ducts as well as in plenums. When necessary, plenums were cut open for repairs. Leaks were sealed with Latex mastic and fiberglass tape. Outside ducts were covered or wrapped with insulation. Unducted returns were sealed with duct board. In some cases, leakage was corrected by merely reconnecting ducts and boots.« less

Dengue fever in the San Juan Bay Estuary: Evaluating the ...

EPA Pesticide Factsheets

Dengue is transmitted by Aedes aegypti, a species that thrives in cities. Here we ask which elements within the urban environment could be managed to reduce the potential for Dengue occurrence. In particular, we study the potential of wetlands in the SJBE to buffer from vector proliferation. Wetlands provide ecosystem services such as heat and water hazard mitigation, water purification and habitat for a diversity of species, all of which are factors that have been shown to affect Dengue vectors. As such, we hypothesize that within coastal neighborhoods in the SJBE wetlands, ecosystem services lead to lower Dengue occurrence. We test this hypothesis using Dengue data from 2010-2013, which includes the largest epidemic in PR history. Our analytical model includes relevant socio-economic factors and environmental controls that may also affect Dengue dynamics. Results indicated a negative effect of neighborhood mangrove cover and a positive effect of percent flood area on Dengue prevalence. Moreover, heat hazards were positively correlated with dengue prevalence and negatively correlated with neighborhood mangrove cover. Dengue prevalence did not correlate with herbaceous wetlands, or with the ecosystem services of water quality or vertebrate species richness. Mosquito borne diseases are an increasingly important health concern, which pose great challenges for safe and sustainable control and eradication. This reality calls for management approaches that consider m

Characterization of the mechanical and physical properties of TD-NiCr (Ni-20Cr-2ThO2) alloy sheet

NASA Technical Reports Server (NTRS)

Fritz, L. J.; Koster, W. P.; Taylor, R. E.

1973-01-01

Sheets of TD-NiCr processed using techniques developed to produce uniform material were tested to supply mechanical and physical property data. Two heats each of 0.025 and 0.051 cm thick sheet were tested. Mechanical properties evaluated included tensile, modulus of elasticity, Poisson's Ratio, compression, creep-rupture, creep strength, bearing strength, shear strength, sharp notch and fatigue strength. Test temperatures covered the range from ambient to 1589K. Physical properties were also studied as a function of temperature. The physical properties measured were thermal conductivity, linear thermal expansion, specific heat, total hemispherical emittance, thermal diffusivity, and electrical conductivity.

Novel Natural Convection Heat Sink Design Concepts From First Principles

DTIC Science & Technology

2016-06-01

NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited NOVEL NATURAL ...COVERED Master’s Thesis 4. TITLE AND SUBTITLE NOVEL NATURAL CONVECTION HEAT SINK DESIGN CONCEPTS FROM FIRST PRINCIPLES 5. FUNDING NUMBERS 6...geometric structures that incorporate the principles of the stack effect to improve the heat transfer capability of a heat sink under natural convection

Study Guide for Fundamentals of Solar Heating: A Correspondence Course for the Airconditioning Industry.

ERIC Educational Resources Information Center

Sheet Metal and Air Conditioning Contractors National Association, Vienna, VA.

This study guide groups eleven lessons into four study units. The first unit discusses the development and basic concepts of solar heating. The second unit deals with the nomenclature of the solar heating system. The third study unit covers sizing of the solar heating system to meet demand and discusses the operation of the total system. The…

A Global Assessment of Oceanic Heat Loss: Conductive Cooling and Hydrothermal Redistribution of Heat

NASA Astrophysics Data System (ADS)

Hasterok, D. P.; Chapman, D. S.; Davis, E. E.

2011-12-01

A new dataset of ~15000 oceanic heat flow measurements is analyzed to determine the conductive heat loss through the seafloor. Many heat flow values in seafloor younger than 60 Ma are lower than predicted by models of conductively cooled lithosphere. This heat flow deficit is caused by ventilated hydrothermal circulation discharging at crustal outcrops or through thin sedimentary cover. Globally filtering of heat flow data to retain sites with sediment cover >400 m thick and located >60 km from the nearest seamount minimizes the effect of hydrothermal ventilation. Filtered heat flow exhibit a much higher correlation coefficient with seafloor age (up to 0.95 for filtered data in contrast to 0.5 for unfiltered data) and lower variability (reduction by 30%) within an age bin. A small heat flow deficit still persists at ages <25 Ma, possibly as a result of global filtering limitations and incomplete thermal rebound following sediment burial. Detailed heat flow surveys co-located with seismic data can identify environments favoring conductive heat flow; heat flow collected in these environments is higher than that determined by the global dataset, and is more consistent with conductive cooling of the lithosphere. The new filtered data analysis and a growing number of site specific surveys both support estimates of global heat loss in the range 40-47 TW. The estimated hydrothermal deficit is consistent with estimates from geochemical studies ~7 TW, but is a few TW lower than previous estimates derived from heat flow determinations.

Development and application of a generic CFD toolkit covering the heat flows in combined solid-liquid systems with emphasis on the thermal design of HiLumi superconducting magnets

NASA Astrophysics Data System (ADS)

Bozza, Gennaro; Malecha, Ziemowit M.; Van Weelderen, Rob

2016-12-01

The main objective of this work is to develop a robust multi-region numerical toolkit for the modeling of heat flows in combined solid-liquid systems. Specifically heat transfer in complex cryogenic system geometries involving super-fluid helium. The incentive originates from the need to support the design of superconductive magnets in the framework of the HiLumi-LHC project (Brüning and Rossi, 2015) [1]. The intent is, instead of solving heat flows in restricted domains, to be able to model a full magnet section in one go including all relevant construction details as accurately as possible. The toolkit was applied to the so-called MQXF quadrupole magnet design. Parametrisation studies were used to find a compromise in thermal design and electro-mechanical construction constraints. The cooling performance is evaluated in terms of temperature margin of the magnets under full steady state heat load conditions and in terms of maximal sustainable load. We also present transient response to pulse heat loads of varying duration and power and the system response to time-varying cold source temperatures.

Basic Comfort Heating Principles.

ERIC Educational Resources Information Center

Dempster, Chalmer T.

The material in this beginning book for vocational students presents fundamental principles needed to understand the heating aspect of the sheet metal trade and supplies practical experience to the student so that he may become familiar with the process of determining heat loss for average structures. Six areas covered are: (1) Background…

Satellite remotely-sensed land surface parameters and their climatic effects for three metropolitan regions

USGS Publications Warehouse

Xian, George

2008-01-01

By using both high-resolution orthoimagery and medium-resolution Landsat satellite imagery with other geospatial information, several land surface parameters including impervious surfaces and land surface temperatures for three geographically distinct urban areas in the United States – Seattle, Washington, Tampa Bay, Florida, and Las Vegas, Nevada, are obtained. Percent impervious surface is used to quantitatively define the spatial extent and development density of urban land use. Land surface temperatures were retrieved by using a single band algorithm that processes both thermal infrared satellite data and total atmospheric water vapor content. Land surface temperatures were analyzed for different land use and land cover categories in the three regions. The heterogeneity of urban land surface and associated spatial extents were shown to influence surface thermal conditions because of the removal of vegetative cover, the introduction of non-transpiring surfaces, and the reduction in evaporation over urban impervious surfaces. Fifty years of in situ climate data were integrated to assess regional climatic conditions. The spatial structure of surface heating influenced by landscape characteristics has a profound influence on regional climate conditions, especially through urban heat island effects.

Energy feedbacks of northern high-latitude ecosystems to the climate system due to reduced snow cover during 20th century warming

USGS Publications Warehouse

Euskirchen, E.S.; McGuire, A.D.; Chapin, F.S.

2007-01-01

The warming associated with changes in snow cover in northern high-latitude terrestrial regions represents an important energy feedback to the climate system. Here, we simulate snow cover-climate feedbacks (i.e. changes in snow cover on atmospheric heating) across the Pan-arctic over two distinct warming periods during the 20th century, 1910-1940 and 1970-2000. We offer evidence that increases in snow cover-climate feedbacks during 1970-2000 were nearly three times larger than during 1910-1940 because the recent snow-cover change occurred in spring, when radiation load is highest, rather than in autumn. Based on linear regression analysis, we also detected a greater sensitivity of snow cover-climate feedbacks to temperature trends during the more recent time period. Pan-arctic vegetation types differed substantially in snow cover-climate feedbacks. Those with a high seasonal contrast in albedo, such as tundra, showed much larger changes in atmospheric heating than did those with a low seasonal contrast in albedo, such as forests, even if the changes in snow-cover duration were similar across the vegetation types. These changes in energy exchange warrant careful consideration in studies of climate change, particularly with respect to associated shifts in vegetation between forests, grasslands, and tundra. ?? 2007 Blackwell Publishing Ltd.

Snow distribution and heat flow in the taiga

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sturm, M.

1992-05-01

The trees of the taiga intercept falling snow and cause it to become distributed in an uneven fashion. Around aspen and birch, cone-shaped accumulations form. Beneath large spruce trees, the snow cover is depleted, forming a bowl-shaped depression called a tree well. Small spruce trees become covered with snow, creating cavities that funnel cold air to the snow/ground interface. The depletion of snow under large spruce trees results in greater heat loss from the ground. A finite difference model suggests that heat flow from tree wells can be more than twice that of undisturbed snow. In forested watersheds, this increasemore » can be a significant percentage of the total winter energy exchange.« less

Observations of elevated Atlantic water heat fluxes at the boundary of the Arctic Basin.

NASA Astrophysics Data System (ADS)

Lincoln, Benjamin; Rippeth, Tom; Lenn, Yueng; Bacon, Sheldon

2014-05-01

The well documented decline in Arctic Sea Ice cover over the past 30 years has outpaced global models as warming in Polar Regions occurs faster than the global mean. The thermohaline circulation brings warm water from the Atlantic Ocean into the Arctic basin. This Atlantic water circulates at depth and contains sufficient heat to melt the sea ice cover several times over. Recent studies have shown that this Atlantic water has warmed and shoaled over recent decades (Polyakov et al, 2010). The stability of the upper Arctic Ocean has also changed, with stratification reduced in the Eurasian basin but increased in the Canada basin. Along with an increased availability of heat the reduction in sea ice cover allows greater potential for wind to input energy to the ocean to vertically mix heat to the surface and further melt sea ice. Direct measurements of vertical mixing rates across the Arctic are essential to understanding the changes in this supply of heat from below, but are scarce due to the challenges of making such measurements in the harsh Arctic environment. We present measurements of turbulent kinetic energy dissipation (ɛ) within the top 500 m of the water column using microstructure measurements made both in open water and under ice during 4 different years. Mean rates of dissipation in the Atlantic water thermocline are calculated and compared for data collected in the European, Siberian and Canadian Arctic, including measurements from 2007 and 2012 when record minimum sea ice extents were recorded. Diapycnal heat fluxes from the mean Atlantic water dissipation rates were calculated from these mean dissipation rates and show significant variation across the Arctic Basin. Profiles in the deep basin generally revealed very low rates of dissipation were low ɛ<10-9Wkg-1 and as such heat fluxes of AW were correspondingly low Fh=0.1-0.5Wm-2. However double diffusive staircases were present in all such casts and so vertical transfer of heat may be increased by diffusive fluxes. Dissipation rates were enhanced by up to 3 orders of magnitude at the boundaries of the Arctic basin with the highest rates North of Svalbard and decreasing ɛ anticlockwise around the basin with low ɛ in the Canada basin. Enhanced heat fluxes at the boundaries ranged from 10-100 Wm-2 north of Svalbard decreasing to 2-5 Wm-2 along the Laptev shelf slope and less than 0.5 Wm-2 along the East Siberian slope and Lomonosov ridge. In the Canada basin heat fluxes at the boundary were less than 0.2 Wm-2. --- Arctic Ocean Warming Contributes to Reduced Polar Ice Cap Igor V. Polyakov, Leonid A. Timokhov, Vladimir A. Alexeev, Sheldon Bacon, Igor A. Dmitrenko, Louis Fortier, et al. in Journal of Physical Oceanography (2010)

A comparison of fuzzy logic and cluster renewal approaches for heat transfer modeling in a 1296 t/h CFB boiler with low level of flue gas recirculation

NASA Astrophysics Data System (ADS)

Błaszczuk, Artur; Krzywański, Jarosław

2017-03-01

The interrelation between fuzzy logic and cluster renewal approaches for heat transfer modeling in a circulating fluidized bed (CFB) has been established based on a local furnace data. The furnace data have been measured in a 1296 t/h CFB boiler with low level of flue gas recirculation. In the present study, the bed temperature and suspension density were treated as experimental variables along the furnace height. The measured bed temperature and suspension density were varied in the range of 1131-1156 K and 1.93-6.32 kg/m3, respectively. Using the heat transfer coefficient for commercial CFB combustor, two empirical heat transfer correlation were developed in terms of important operating parameters including bed temperature and also suspension density. The fuzzy logic results were found to be in good agreement with the corresponding experimental heat transfer data obtained based on cluster renewal approach. The predicted bed-to-wall heat transfer coefficient covered a range of 109-241 W/(m2K) and 111-240 W/(m2K), for fuzzy logic and cluster renewal approach respectively. The divergence in calculated heat flux recovery along the furnace height between fuzzy logic and cluster renewal approach did not exceeded ±2%.

Conference on Occupational Health Aspects of Advanced Composite Technology in the Aerospace Industry Held in Dayton, Ohio on 6-9 February 1989. Volume 1. Executive Summary

DTIC Science & Technology

1989-03-01

skins and fiber glass covers. Processing or curing (the application of heat and pressure to consolidate the laminate and cross-link the matrix) was...stabilizer skins and fiberglass covers. Processing or curing (the application of heat and pressure to consolidate the laminate and cross-link the matrix) is...high stiffness fibers to develop a common understanding of advanced . -nposites. Areas addressed were applications , materials manufacturing and use

The phonon theory of liquid thermodynamics

PubMed Central

Bolmatov, D.; Brazhkin, V. V.; Trachenko, K.

2012-01-01

Heat capacity of matter is considered to be its most important property because it holds information about system's degrees of freedom as well as the regime in which the system operates, classical or quantum. Heat capacity is well understood in gases and solids but not in the third main state of matter, liquids, and is not discussed in physics textbooks as a result. The perceived difficulty is that interactions in a liquid are both strong and system-specific, implying that the energy strongly depends on the liquid type and that, therefore, liquid energy can not be calculated in general form. Here, we develop a phonon theory of liquids where this problem is avoided. The theory covers both classical and quantum regimes. We demonstrate good agreement of calculated and experimental heat capacity of 21 liquids, including noble, metallic, molecular and hydrogen-bonded network liquids in a wide range of temperature and pressure. PMID:22639729

Method and apparatus for extracting tritium and preparing radioactive waste for disposal

DOEpatents

Heung, L.K.

1994-03-29

Apparatus is described for heating an object such as a nuclear target bundle to release and recover hydrogen and contain the disposable residue for disposal. The apparatus comprises an inverted furnace, a sleeve/crucible assembly for holding and enclosing the bundle, conveying equipment for placing the sleeve onto the crucible and loading the bundle into the sleeve/crucible, a lift for raising the enclosed bundle into the furnace, and hydrogen recovery equipment including a trap and strippers, all housed in a containment having negative internal pressure. The crucible/sleeve assembly has an internal volume that is sufficient to enclose and hold the bundle before heating; the crucible's internal volume is sufficient by itself to hold and enclose the bundle's volume after heating. The crucible can then be covered and disposed of; the sleeve, on the other hand, can be reused. 4 figures.

Milliwatt Generator Project

NASA Astrophysics Data System (ADS)

Latimer, T. W.; Rinehart, G. H.

1992-05-01

This report covers progress on the Milliwatt Generator Project from April 1986 through March 1988. Activities included fuel processing and characterization, production of heat sources, fabrication of pressure-burst test units, compatibility studies, impact testing, and examination of surveillance units. The major task of the Los Alamos Milliwatt Generator Project is to fabricate MC2893A heat sources (4.0 W) for MC2730A radioisotope thermoelectric generators (RTG's) and MC3599 heat sources (4.5 W) for MC3500 RTG's. The MWG Project interfaces with the following contractors: Sandia National Laboratories, Albuquerque (designer); E.I. du Pont de Nemours and Co. (Inc.), Savannah River Plant (fuel); Monsanto Research Corporation, Mound Facility (metal hardware); and General Electric Company, Neutron Devices Department (RTG's). In addition to MWG fabrication activities, Los Alamos is involved in (1) fabrication of pressure-burst test units, (2) compatibility testing and evaluation, (3) examination of surveillance units, and (4) impact testing and subsequent examination of compatibility and surveillance units.

Climate Sensitivity to Realistic Solar Heating of Snow and Ice

NASA Astrophysics Data System (ADS)

Flanner, M.; Zender, C. S.

2004-12-01

Snow and ice-covered surfaces are highly reflective and play an integral role in the planetary radiation budget. However, GCMs typically prescribe snow reflection and absorption based on minimal knowledge of snow physical characteristics. We performed climate sensitivity simulations with the NCAR CCSM including a new physically-based multi-layer snow radiative transfer model. The model predicts the effects of vertically resolved heating, absorbing aerosol, and snowpack transparency on snowpack evolution and climate. These processes significantly reduce the model's near-infrared albedo bias over deep snowpacks. While the current CCSM implementation prescribes all solar radiative absorption to occur in the top 2 cm of snow, we estimate that about 65% occurs beneath this level. Accounting for the vertical distribution of snowpack heating and more realistic reflectance significantly alters snowpack depth, surface albedo, and surface air temperature over Northern Hemisphere regions. Implications for the strength of the ice-albedo feedback will be discussed.

Preliminary measurements on heat balance in pneumatic tires

NASA Technical Reports Server (NTRS)

Nybakken, G. H.; Collart, D. Y.; Staples, R. J.; Lackey, J. I.; Clark, S. K.; Dodge, R. N.

1973-01-01

A variety of tests was undertaken to determine the nature of heat generation associated with a pneumatic tire operating under various conditions. Tests were conducted to determine the magnitude and distribution of internally generated heat caused by hysteresis in the rubber and ply fabric in an automobile tire operating under conditions of load, pressure, and velocity representative of normal operating conditions. These included tests at various yaw angles and tests with braking applied. In other tests, temperature sensors were mounted on a road to measure the effect of a tire rolling over and an attempt was made to deduce the magnitude and nature of interfacial friction from the resulting information. In addition, tests were performed using the scratch plate technique to determine the nature of the motion between the tire and road. Finally, a model tire was tested on a roadwheel, the surface covering which could be changed, and an optical pyrometer was used to measure rubber surface temperatures.

Regular network model for the sea ice-albedo feedback in the Arctic.

PubMed

Müller-Stoffels, Marc; Wackerbauer, Renate

2011-03-01

The Arctic Ocean and sea ice form a feedback system that plays an important role in the global climate. The complexity of highly parameterized global circulation (climate) models makes it very difficult to assess feedback processes in climate without the concurrent use of simple models where the physics is understood. We introduce a two-dimensional energy-based regular network model to investigate feedback processes in an Arctic ice-ocean layer. The model includes the nonlinear aspect of the ice-water phase transition, a nonlinear diffusive energy transport within a heterogeneous ice-ocean lattice, and spatiotemporal atmospheric and oceanic forcing at the surfaces. First results for a horizontally homogeneous ice-ocean layer show bistability and related hysteresis between perennial ice and perennial open water for varying atmospheric heat influx. Seasonal ice cover exists as a transient phenomenon. We also find that ocean heat fluxes are more efficient than atmospheric heat fluxes to melt Arctic sea ice.

Observational evidence for cloud cover enhancement over western European forests.

PubMed

Teuling, Adriaan J; Taylor, Christopher M; Meirink, Jan Fokke; Melsen, Lieke A; Miralles, Diego G; van Heerwaarden, Chiel C; Vautard, Robert; Stegehuis, Annemiek I; Nabuurs, Gert-Jan; de Arellano, Jordi Vilà-Guerau

2017-01-11

Forests impact regional hydrology and climate directly by regulating water and heat fluxes. Indirect effects through cloud formation and precipitation can be important in facilitating continental-scale moisture recycling but are poorly understood at regional scales. In particular, the impact of temperate forest on clouds is largely unknown. Here we provide observational evidence for a strong increase in cloud cover over large forest regions in western Europe based on analysis of 10 years of 15 min resolution data from geostationary satellites. In addition, we show that widespread windthrow by cyclone Klaus in the Landes forest led to a significant decrease in local cloud cover in subsequent years. Strong cloud development along the downwind edges of larger forest areas are consistent with a forest-breeze mesoscale circulation. Our results highlight the need to include impacts on cloud formation when evaluating the water and climate services of temperate forests, in particular around densely populated areas.

Observational evidence for cloud cover enhancement over western European forests

PubMed Central

Teuling, Adriaan J.; Taylor, Christopher M.; Meirink, Jan Fokke; Melsen, Lieke A.; Miralles, Diego G.; van Heerwaarden, Chiel C.; Vautard, Robert; Stegehuis, Annemiek I.; Nabuurs, Gert-Jan; de Arellano, Jordi Vilà-Guerau

2017-01-01

Forests impact regional hydrology and climate directly by regulating water and heat fluxes. Indirect effects through cloud formation and precipitation can be important in facilitating continental-scale moisture recycling but are poorly understood at regional scales. In particular, the impact of temperate forest on clouds is largely unknown. Here we provide observational evidence for a strong increase in cloud cover over large forest regions in western Europe based on analysis of 10 years of 15 min resolution data from geostationary satellites. In addition, we show that widespread windthrow by cyclone Klaus in the Landes forest led to a significant decrease in local cloud cover in subsequent years. Strong cloud development along the downwind edges of larger forest areas are consistent with a forest-breeze mesoscale circulation. Our results highlight the need to include impacts on cloud formation when evaluating the water and climate services of temperate forests, in particular around densely populated areas. PMID:28074840

Development of Fire Resistant/Heat Resistant Sewing Thread

DTIC Science & Technology

2016-03-01

Final 3. DATES COVERED (From - To) October 2014 – June 2015 4. TITLE AND SUBTITLE DEVELOPMENT OF FIRE RESISTANT /HEAT RESISTANT SEWING THREAD 5a...core to sheath ratio of 70:30 will offer a high performance, low cost sewing thread with required fire resistant /heat resistant properties. 15...Properties ............................................................................... 18        1      DEVELOPMENT OF  FIRE   RESISTANT /HEAT

Modeling the Thickness of Perennial Ice Covers on Stratified Lakes of the Taylor Valley, Antarctica

NASA Technical Reports Server (NTRS)

Obryk, M. K.; Doran, P. T.; Hicks, J. A.; McKay, C. P.; Priscu, J. C.

2016-01-01

A one-dimensional ice cover model was developed to predict and constrain drivers of long term ice thickness trends in chemically stratified lakes of Taylor Valley, Antarctica. The model is driven by surface radiative heat fluxes and heat fluxes from the underlying water column. The model successfully reproduced 16 years (between 1996 and 2012) of ice thickness changes for west lobe of Lake Bonney (average ice thickness = 3.53 m; RMSE = 0.09 m, n = 118) and Lake Fryxell (average ice thickness = 4.22 m; RMSE = 0.21 m, n = 128). Long-term ice thickness trends require coupling with the thermal structure of the water column. The heat stored within the temperature maximum of lakes exceeding a liquid water column depth of 20 m can either impede or facilitate ice thickness change depending on the predominant climatic trend (temperature cooling or warming). As such, shallow (< 20 m deep water columns) perennially ice-covered lakes without deep temperature maxima are more sensitive indicators of climate change. The long-term ice thickness trends are a result of surface energy flux and heat flux from the deep temperature maximum in the water column, the latter of which results from absorbed solar radiation.

Apprentice Heating Systems Specialist, 11-1. Military Curriculum Materials for Vocational and Technical Education.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus. National Center for Research in Vocational Education.

This military-developed text consists of four volumes of materials for use by those studying to become apprentice heating system specialists. Covered in the individual volumes are the following topics: related subjects (basic electricity, electrical controls, pipe and copper tubing, the principles of heating, fuels, and fuel systems); heating…

Air Conditioning, Heating, and Ventilating: Construction, Supervision, and Inspection. Course of Study.

ERIC Educational Resources Information Center

Messer, John D.

This course of study on air conditioning, heating, and ventilating is part of a construction, supervision, and inspection series, which provides instructional materials for community or junior college technical courses in the inspection program. Material covered pertains to: piping and piping systems; air movers; boilers; heat exchangers; cooling…

Papers presented to the Conference on Heat and Detachment in Crustal Extension on Continents and Planets

NASA Technical Reports Server (NTRS)

1985-01-01

Several topics relative to heat and detachment in crustal extension on continents and planets are discussed. Rifting on Venus, heat flow and continental breakup, magnetism, the mountains and tectonic processes of Io, and the ductile extension of planetary lithospheres are among the topics covered.

Sun Heats, Cools Columbus Tech.

ERIC Educational Resources Information Center

American School and University, 1980

1980-01-01

Solar energy heats and cools the newest building on the campus of Columbus Technical Institute in Ohio. A solar demonstration project grant from the Department of Energy covered about 77 percent of the solar cost. (Author/MLF)

What land covers are effective in mitigating a heat island in urban building rooftop?

NASA Astrophysics Data System (ADS)

Lee, S.; Ryu, Y.

2014-12-01

Since the 20th century, due to the rapid urbanization many urban environment problems have got blossomed and above all heat island has been recognized as an important issue. There are several causes of urban heat island, but land cover change occupies the largest portion of them. Owing to urban expansion, vegetation is changed into asphalt pavements and concrete buildings, which reduces latent heat flux. To mitigate the problems, people enlarge vegetation covers such as planting street trees, making rooftop gardens and constructing parks or install white roofs that feature high albedo on a building. While the white roofs reflect about 70% of solar radiation and absorb less radiation, vegetation has low albedo but cools the air through transpiration and fixes carbon dioxide through photosynthesis. There are some studies concerning which one is more effective to mitigate heat island between the green roof and white roof. This study compares the green roof and white roof and additionally considers carbon fixation that has not been treated in other studies. Furthermore, this study ascertains an efficiency of solar-cell panel that is used for building roof recently. The panel produces electric power but has low albedo which could warm the air. The experiment is conducted at the rooftop in Seoul, Korea and compares green roof (grass), white roof (painted cover), black roof (solar panel) and normal painted roof. Surface temperature and albedo are observed for the four roof types and incoming shortwave, outgoing longwave and carbon flux are measured in green roof solely. In the case of solar panels, the electricity generation is calculated from the incoming radiation. We compute global warming potentials for the four roof types and test which roof type is most effective in reducing global warming potential.

What Is the Use of Elephant Hair?

PubMed Central

Myhrvold, Conor L.; Stone, Howard A.; Bou-Zeid, Elie

2012-01-01

The idea that low surface densities of hairs could be a heat loss mechanism is understood in engineering and has been postulated in some thermal studies of animals. However, its biological implications, both for thermoregulation as well as for the evolution of epidermal structures, have not yet been noted. Since early epidermal structures are poorly preserved in the fossil record, we study modern elephants to infer not only the heat transfer effect of present-day sparse hair, but also its potential evolutionary origins. Here we use a combination of theoretical and empirical approaches, and a range of hair densities determined from photographs, to test whether sparse hairs increase convective heat loss from elephant skin, thus serving an intentional evolutionary purpose. Our conclusion is that elephants are covered with hair that significantly enhances their thermoregulation ability by over 5% under all scenarios considered, and by up to 23% at low wind speeds where their thermoregulation needs are greatest. The broader biological significance of this finding suggests that maintaining a low-density hair cover can be evolutionary purposeful and beneficial, which is consistent with the fact that elephants have the greatest need for heat loss of any modern terrestrial animal because of their high body-volume to skin-surface ratio. Elephant hair is the first documented example in nature where increasing heat transfer due to a low hair density covering may be a desirable effect, and therefore raises the possibility of such a covering for similarly sized animals in the past. This elephant example dispels the widely-held assumption that in modern endotherms body hair functions exclusively as an insulator and could therefore be a first step to resolving the prior paradox of why hair was able to evolve in a world much warmer than our own. PMID:23071700

Thermal envelope field measurements in an energy-efficient office and dormitory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christian, J.E.

1983-04-01

A 345-m/sup 2/ earth-covered structure located at Oak Ridge National Laboratory is the focus of a DOE-sponsored building envelope research project. Based on field-measured data, heating the office and dormitory building over the 1981-1982 heating season cost $1.70/m/sup 2/ ($0.16/ft/sup 2/), assuming the cost of electricity to be $0.057/kWh. The building's thermal integrity factor is 0.016 kWh/m/sup 2/ /sup 0/C (2.8 Btu/ft/sup 2/ /sup 0/F). A preliminary DOE-2 model estimates the monthly electric energy needs for heating to be within 5% of our field data-derived estimates. DOE-2 building simulations suggest that this earth-covered, passively solar heated office dormitory saves 30%more » of the space heating and 26% of the cooling costs of an energy-efficient above grade structure. A preliminary winter energy balance has been generated from data collected in February and March and provides a fractional breakdown of thermal losses and gains. Performances have been isolated for several of the energy-conserving components: the earth-covered roof, the bermed wall, and the nonvented Trombe wall. The earth-covered roof system showed an overall thermal transmittance of 0.18 W/m/sup 2/ /sup 0/C (R = 31 h ft/sup 2/ /sup 0/F Btu/sup -1/). The thermocouple wells in the earth surrounding the building indicate that burying a wall is more energy efficient than berming. During one week in February, the Trombe wall produced a 50% greater net thermal gain to the building than an equivalent area of south-facing windows.« less

Tables of critical-flow functions and thermodynamic properties for methane and computational procedures for both methane and natural gas

NASA Technical Reports Server (NTRS)

Johnson, R. C.

1972-01-01

Procedures for calculating the mass flow rate of methane and natural gas through nozzles are given, along with the FORTRAN 4 subroutines used to make these calculations. Three sets of independent variables are permitted in these routines. In addition to the plenum pressure and temperature, the third independent variable is either nozzle exit pressure, Mach number, or temperature. A critical-flow factor that becomes a convenient means for determining the mass flow rate of methane through critical-flow nozzles is tabulated. Other tables are included for nozzle throat velocity and critical pressure, density, and temperature ratios, along with some thermodynamic properties of methane, including compressibility factor, enthalpy, entropy, specific heat, specific-heat ratio, and speed of sound. These tabulations cover a temperature range from 120 to 600 K and pressures to 3 million N/sq m.

Mercury concentration in phytoplankton in response to warming of an autumn - winter season.

PubMed

Bełdowska, Magdalena; Kobos, Justyna

2016-08-01

Among other climate changes in the southern Baltic, there is a tendency towards warming, especially in autumn-winter. As a result, the ice cover on the coastal zone often fails to occur. This is conducive to the thriving of phytoplankton, in which metals, including mercury, can be accumulated. The dry deposition of atmospheric Hg during heating seasons is more intense than in non-heating seasons, owing to the combustion of fossil fuels for heating purposes. This has resulted in studies into the role of phytoplankton in the introduction of Hg into the first link of trophic chain, as a function of autumn and winter warming in the coastal zone of the lagoon. The studies were conducted at two stations in the coastal zone of the southern Baltic, in the Puck Lagoon, between December 2011 and May 2013. The obtained results show that, in the estuary region, the lack of ice cover can lead to a 30% increase and during an "extremely warm" autumn and winter an increase of up to three-fold in the mean annual Hg pool in phytoplankton (mass of Hg in phytoplankton per liter of seawater). The Hg content in phytoplankton was higher when Mesodinium rubrum was prevalent in the biomass, while the proportion of dinoflagellates was small. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of heat stress on age at first calving of Japanese Black cows in Okinawa.

PubMed

Oikawa, Takuro

2017-03-01

Calving records from birth certificates of cows were analyzed to investigate the effect of heat stress on age at first calving (AFC) of Japanese Black cows. The data set covered 20 years (1990-2009) of calving records. Total number of records was 9279. Daily weather information from weather stations in the vicinity of the farms was used. Temperature-humidity index (THI) fitted to a linear model covered 30 days pre-insemination to 61 days post-insemination. Statistical analysis was conducted with procedures of SAS/STAT. Preliminary analysis showed that THI of the lowest temperature and humidity was most conducive to AFC. Covariance analysis, including main effect of sire, farm and year of insemination and covariates of THI on days showed that regression coefficients of THI on day -7, day -2 and day +31 were statistically significant. The estimated piecewise regression line showed different responses of AFC to THI on days: roof-shasped downward trend on day -7, hockey-stick shaped upward trend on day -2 and day +31. The difference among the estimated regression lines may be caused by direct and indirect factors on reproduction: indirect effect of reduced feed intake, failure of conception at previous insemination, direct effect of heat stress on oocyte and embryo development. © 2016 Japanese Society of Animal Science.

Understanding land use change impacts on microclimate using Weather Research and Forecasting (WRF) model

NASA Astrophysics Data System (ADS)

Li, Xia; Mitra, Chandana; Dong, Li; Yang, Qichun

2018-02-01

To explore potential climatic consequences of land cover change in the Kolkata Metropolitan Development area, we projected microclimate conditions in this area using the Weather Research and Forecasting (WRF) model driven by future land use scenarios. Specifically, we considered two land conversion scenarios including an urbanization scenario that all the wetlands and croplands would be converted to built-up areas, and an irrigation expansion scenario in which all wetlands and dry croplands would be replaced by irrigated croplands. Results indicated that land use and land cover (LULC) change would dramatically increase regional temperature in this area under the urbanization scenario, but expanded irrigation tended to have a cooling effect. In the urbanization scenario, precipitation center tended to move eastward and lead to increased rainfall in eastern parts of this region. Increased irrigation stimulated rainfall in central and eastern areas but reduced rainfall in southwestern and northwestern parts of the study area. This study also demonstrated that urbanization significantly reduced latent heat fluxes and albedo of land surface; while increased sensible heat flux changes following urbanization suggested that developed land surfaces mainly acted as heat sources. In this study, climate change projection not only predicts future spatiotemporal patterns of multiple climate factors, but also provides valuable insights into policy making related to land use management, water resource management, and agriculture management to adapt and mitigate future climate changes in this populous region.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rose, Brian E. J.; Cronin, Timothy W.; Bitz, Cecilia M., E-mail: brose@albany.edu

Planetary obliquity determines the meridional distribution of the annual mean insolation. For obliquity exceeding 55°, the weakest insolation occurs at the equator. Stable partial snow and ice cover on such a planet would be in the form of a belt about the equator rather than polar caps. An analytical model of planetary climate is used to investigate the stability of ice caps and ice belts over the widest possible range of parameters. The model is a non-dimensional diffusive Energy Balance Model, representing insolation, heat transport, and ice−albedo feedback on a spherical planet. A complete analytical solution for any obliquity ismore » given and validated against numerical solutions of a seasonal model in the “deep-water” regime of weak seasonal ice line migration. Multiple equilibria and unstable transitions between climate states (ice-free, Snowball, or ice cap/belt) are found over wide swaths of parameter space, including a “Large Ice-Belt Instability” and “Small Ice-Belt Instability” at high obliquity. The Snowball catastrophe is avoided at weak radiative forcing in two different scenarios: weak albedo feedback and inefficient heat transport (favoring stable partial ice cover), or efficient transport at high obliquity (favoring ice-free conditions). From speculative assumptions about distributions of planetary parameters, three-fourths to four-fifths of all planets with stable partial ice cover should be in the form of Earth-like polar caps.« less

A one- and two-layer model for estimating evapotranspiration with remotely sensed surface temperature and ground-based meteorological data over partial canopy cover

NASA Technical Reports Server (NTRS)

Kustas, William P.; Choudhury, Bhaskar J.; Kunkel, Kenneth E.

1989-01-01

Surface-air temperature differences are commonly used in a bulk resistance equation for estimating sensible heat flux (H), which is inserted in the one-dimensional energy balance equation to solve for the latent heat flux (LE) as a residual. Serious discrepancies between estimated and measured LE have been observed for partial-canopy-cover conditions, which are mainly attributed to inappropriate estimates of H. To improve the estimates of H over sparse canopies, one- and two-layer resistance models that account for some of the factors causing poor agreement are developed. The utility of the two models is tested with remotely sensed and micrometeorological data for a furrowed cotton field with 20 percent cover and a dry soil surface. It is found that the one-layer model performs better than the two-layer model when a theoretical bluff-body correction for heat transfer is used instead of an empirical adjustment; otherwise, the two-layer model is better.

Low thermal resistance power module assembly

DOEpatents

Hassani, Vahab; Vlahinos, Andreas; Bharathan, Desikan

2010-12-28

A power module assembly (400) with low thermal resistance and enhanced heat dissipation to a cooling medium. The assembly includes a heat sink or spreader plate (410) with passageways or openings (414) for coolant that extend through the plate from a lower surface (411) to an upper surface (412). A circuit substrate (420) is provided and positioned on the spreader plate (410) to cover the coolant passageways. The circuit substrate (420) includes a bonding layer (422) configured to extend about the periphery of each of the coolant passageways and is made up of a substantially nonporous material. The bonding layer (422) may be solder material which bonds to the upper surface (412) of the plate to provide a continuous seal around the upper edge of each opening (414) in the plate. The assembly includes power modules (430) mounted on the circuit substrate (420) on a surface opposite the bonding layer (422). The power modules (430) are positioned over or proximal to the coolant passageways.

Advective and Conductive Heat Flow Budget Across the Wagner Basin, Northern Gulf of California

NASA Astrophysics Data System (ADS)

Neumann, F.; Negrete-Aranda, R.; Contreras, J.; Müller, C.; Hutnak, M.; Gonzalez-Fernandez, A.; Harris, R. N.; Sclater, J. G.

2015-12-01

In May 2015, we conducted a cruise across the northern Gulf of California, an area of continental rift basin formation and rapid deposition of sediments. The cruise was undertaken aboard the R/V Alpha Helix; our goal was to study variation in superficial conductive heat flow, lateral changes in the shallow thermal conductivity structure, and advective transport of heat across the Wagner basin. We used a Fielax heat flow probe with 22 thermistors that can penetrate up to 6 m into the sediment cover. The resulting data set includes 53 new heat flow measurements collected along three profiles. The longest profile (42 km) contains 30 measurements spaced 1-2 km apart. The western part of the Wagner basin (hanging wall block) exhibit low to normal conductive heat flow whereas the eastern part of the basin (foot wall block) heat flow is high to very high (up to 2500 mWm-2). Two other short profiles (12 km long each) focused on resolving an extremely high heat flow anomaly up to 15 Wm-2 located near the intersection between the Wagner bounding fault system and the Cerro Prieto fault. We hypothesize that the contrasting heat flow values observed across the Wagner basin are due to horizontal water circulation through sand layers and fault pathways of high permeability. Circulation appears to be from west (recharge zone) to east (discharge zone). Additionally, our results reveal strong vertical advection of heat due to dehydration reactions and compaction of fine grained sediments.

Wetland Restoration Response Analysis using MODIS and Groundwater Data

PubMed Central

Melesse, Assefa M.; Nangia, Vijay; Wang, Xixi; McClain, Michael

2007-01-01

Vegetation cover and groundwater level changes over the period of restoration are the two most important indicators of the level of success in wetland ecohydrological restoration. As a result of the regular presence of water and dense vegetation, the highest evapotranspiration (latent heat) rates usually occur within wetlands. Vegetation cover and evapotranspiration of large areas of restoration like that of Kissimmee River basin, South Florida will be best estimated using remote sensing technique than point measurements. Kissimmee River basin has been the area of ecological restoration for some years. The current ecohydrological restoration activities were evaluated through fractional vegetation cover (FVC) changes and latent heat flux using Moderate Resolution Imaging Spectroradiometer (MODIS) data. Groundwater level data were also analyzed for selected eight groundwater monitoring wells in the basin. Results have shown that the average fractional vegetation cover and latent heat along 10 km buffer of Kissimmee River between Lake Kissimmee and Lake Okeechobee was higher in 2004 than in 2000. It is evident that over the 5-year period of time, vegetated and areas covered with wetlands have increased significantly especially along the restoration corridor. Analysis of groundwater level data (2000-2004) from eight monitoring wells showed that, the average monthly level of groundwater was increased by 20 cm and 34 cm between 2000 and 2004, and 2000 and 2003, respectively. This change was more evident for wells along the river. PMID:28903205

Heat transfer in a cover-plate preswirl rotating-disk system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pilbrow, R.; Karabay, H.; Wilson, M.

1999-04-01

In most gas turbines, blade-cooling air is supplied from stationary preswirl nozzles that swirl the air in the direction of rotation of the turbine disk. In the cover-plate system, the preswirl nozzles are located radially inward of the blade-cooling holes in the disk, and the swirling air flows radially outward in the cavity between the disk and a cover-plate attached to it. In this combined computational and experimental paper, an axisymmetric elliptic solver, incorporating the Launder-Sharma and the Morse low-Reynolds-number {kappa}-{epsilon} turbulence models, is used to compute the flow and heat transfer. The computed Nusselt numbers for the heated turbinemore » disk are compared with measured values obtained from a rotating-disk rig. Comparisons are presented, for a wide range of coolant flow rates, for rotational Reynolds numbers in the range 0.5 {times} 10{sup 6} to 1.5 {times} 10{sup 6}, and for 0.9 < {beta}{sub p} < 3.1, where {beta}{sub p} is the preswirl ratio (or ratio of the tangential component of velocity of the cooling air at inlet to the system to that of the disk). Agreement between the computed and measured Nusselt numbers is reasonably good, particularly at the larger Reynolds numbers. A simplified numerical simulation is also conducted to show the effect of the swirl ratio and the other flow parameters on the flow and heat transfer in the cover-plate system.« less

What are hot and what are not in an urban landscape: quantifying and explaining the land surface temperature pattern in Beijing, China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuang, Wenhui; Liu, Yue; Dou, Yinyin

Understanding how landscape components affect the urban heat islands is crucial for urban ecological planning and sustainable development. The purpose of this research was to quantify the spatial pattern of land surface temperatures (LSTs) and associated heat fluxes in relation to land-cover types in Beijing, China, using portable infrared thermometers, thermal infrared imagers, and the moderate resolution imaging spectroradiometer. The spatial differences and the relationships between LSTs and the hierarchical landscape structure were analyzed with in situ observations of surface radiation and heat fluxes. Large LST differences were found among various land-use/land-cover types, urban structures, and building materials. Within themore » urban area, the mean LST of urban impervious surfaces was about 6–12°C higher than that of the urban green space. LSTs of built-up areas were on average 3–6°C higher than LSTs of rural areas. The observations for surface radiation and heat fluxes indicated that the differences were caused by different fractions of sensible heat or latent heat flux in net radiation. LSTs decreased with increasing elevation and normalized difference vegetation index. Variations in building materials and urban structure significantly influenced the spatial pattern of LSTs in urban areas. By contrast, elevation and vegetation cover are the major determinants of the LST pattern in rural areas. In summary, to alleviate urban heat island intensity, urban planners and policy makers should pay special attention to the selection of appropriate building materials, the reasonable arrangement of urban structures, and the rational design of landscape components.« less

What are hot and what are not in an urban landscape: quantifying and explaining the land surface temperature pattern in Beijing, China

DOE PAGES

Kuang, Wenhui; Liu, Yue; Dou, Yinyin; ...

2014-12-06

Understanding how landscape components affect the urban heat islands is crucial for urban ecological planning and sustainable development. The purpose of this research was to quantify the spatial pattern of land surface temperatures (LSTs) and associated heat fluxes in relation to land-cover types in Beijing, China, using portable infrared thermometers, thermal infrared imagers, and the moderate resolution imaging spectroradiometer. The spatial differences and the relationships between LSTs and the hierarchical landscape structure were analyzed with in situ observations of surface radiation and heat fluxes. Large LST differences were found among various land-use/land-cover types, urban structures, and building materials. Within themore » urban area, the mean LST of urban impervious surfaces was about 6–12°C higher than that of the urban green space. LSTs of built-up areas were on average 3–6°C higher than LSTs of rural areas. The observations for surface radiation and heat fluxes indicated that the differences were caused by different fractions of sensible heat or latent heat flux in net radiation. LSTs decreased with increasing elevation and normalized difference vegetation index. Variations in building materials and urban structure significantly influenced the spatial pattern of LSTs in urban areas. By contrast, elevation and vegetation cover are the major determinants of the LST pattern in rural areas. In summary, to alleviate urban heat island intensity, urban planners and policy makers should pay special attention to the selection of appropriate building materials, the reasonable arrangement of urban structures, and the rational design of landscape components.« less

Elimination of Acid Cleaning of High Temperature Salt Water Heat Exchangers: Redesigned Pre-Production Full-Scale Heat Pipe Bleed Air Cooler for Shipboard Evaluation

DTIC Science & Technology

2011-11-01

Cleaning of High Temperature Salt Water Heat Exchangers ESTCP WP-200302 Subtitle: Redesigned Pre-production Full-Scale Heat Pipe Bleed Air Cooler For...FINAL 3. DATES COVERED (From - To) 1-Jan-2003 – 1-Oct-2009 4. TITLE AND SUBTITLE Elimination of Acid Cleaning of High Temperature Salt Water Heat...6-5 Figure 6- 6 HP-BAC Tube Sheet Being Immersed in Ultrasonic Cleaning Tank ..................................... 6-6 Figure 6- 7 Heat Pipe

Chapter 5: Residential Furnaces and Boilers Evaluation Protocol. The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurnik, Charles W.; Jacobson, David

The high-efficiency boiler and furnace measure produces gas heating savings resulting from installation of more energy-efficient heating equipment in a residence. Such equipment, which ranges in size from 60 kBtu/hr to 300 kBtu/hr, is installed primarily in single-family homes and multifamily buildings with individual heating systems for each dwelling unit. This protocol does not cover integrated heating and water heating units which can be used in lieu of space heating only equipment.

Optimization of design parameters of low-energy buildings

NASA Astrophysics Data System (ADS)

Vala, Jiří; Jarošová, Petra

2017-07-01

Evaluation of temperature development and related consumption of energy required for heating, air-conditioning, etc. in low-energy buildings requires the proper physical analysis, covering heat conduction, convection and radiation, including beam and diffusive components of solar radiation, on all building parts and interfaces. The system approach and the Fourier multiplicative decomposition together with the finite element technique offers the possibility of inexpensive and robust numerical and computational analysis of corresponding direct problems, as well as of the optimization ones with several design variables, using the Nelder-Mead simplex method. The practical example demonstrates the correlation between such numerical simulations and the time series of measurements of energy consumption on a small family house in Ostrov u Macochy (35 km northern from Brno).

Ionospheres of the terrestrial planets

NASA Astrophysics Data System (ADS)

Schunk, R. W.; Nagy, A. F.

1980-11-01

The theory and observations relating to the ionospheres of the terrestrial planets Venus, the earth, and Mars are reviewed. Emphasis is placed on comparing the basic differences and similarities between the planetary ionospheres. The review covers the plasma and electric-magnetic field environments that surround the planets, the theory leading to the creation and transport of ionization in the ionospheres, the relevant observations, and the most recent model calculations. The theory section includes a discussion of ambipolar diffusion in a partially ionized plasma, diffusion in a fully ionized plasma, supersonic plasma flow, photochemistry, and heating and cooling processes. The sections on observations and model calculations cover the neutral atmosphere composition, the ion composition, the electron density, and the electron, ion, and neutral temperatures.

[Temporal and spatial change of climate resources and meteorological disasters under climate change during winter crop growing season in Guangdong Province, China.

PubMed

Wang, Hua; Chen, Hui Hua; Tang, Li Sheng; Wang, Juan Huai; Tang, Hai Yan

2018-01-01

Trend analysis method was applied to analyze the general variation characteristics of the climate resources and meteorological disasters of growing season of the winter planting in Guangdong before (1961-1996) and after climate warming (1997-2015). Percentile method was employed to determine thresholds for extreme cold and drought in major planting regions, and the characteristics of extreme disasters since climate warming were analyzed. The results showed that, by comparing 1997-2015 with 1961-1996, the heat value in winter growing season increased significantly. The belt with a higher heat value, where the average temperature was ≥15 ℃ and accumulated temperature was ≥2200 ℃·d, covered the main winter production regions as Shaoguan, Zhanjiang, Maoming, Huizhou, Meizhou and Guangzhou. Meanwhile, the precipitation witnessed a slight increase. The regions with precipitations of 250-350 mm included Zhanjiang, Maoming, Huizhou, Guangzhou and Meizhou. Chilling injury in the winter planting season in the regions decreased, the belt with an accumulated chilling of <2 ℃·d covered the major geographic parts of the involved regions as Zhanjiang, Maoming, Guangzhou and Huizhou; and the belt with an accumulated chilling of 8-16 ℃·d covered the major geographic parts of Shaoguan and Meizhou. Meanwhile, the drought days decreased, the belt with drought days ≥50 included the major geographic parts of Zhanjiang, Maoming, Huizhou, Guangzhou and the belt with drought days <50 included the major geographic parts of Shaoguan. The typical case of the extreme disasters showed that the extreme chilling injury and drought in the main producing regions should not be overlooked. Maoming, Huizhou and Meizhou were at higher risk of extreme chilling injury, followed by Shaoguan and Guangzhou. Zhanjiang and Maoming faced the highest risk of extreme drought, Huizhou and Guangzhou took the second place, Shaoguan and Meizhou went last. During 1997-2015, the heat of winter season increased significantly, the trend of chilling and drought decreased, however, the extreme disasters occurred frequently and the risks were higher in winter production areas. It was suggested that the winter planting should be closely integrated with climate resources and the occurrence law of meteorological disasters in growing season.

Radiant Heat Test Facility (RHTF): User Test Planning Guide

NASA Technical Reports Server (NTRS)

DelPapa, Steven

2011-01-01

Test process, milestones and inputs are unknowns to first-time users of the RHTF. The User Test Planning Guide aids in establishing expectations for both NASA and non- NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their test engineering personnel in test planning and execution. Material covered includes a roadmap of the test process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, test article interfaces, and inputs necessary to define test scope, cost, and schedule are included as an appendix to the guide.

Sensitivities Affecting Heat and Urban Heat Island Effect on Local Scale Projected to Neighborhood Scale in Baltimore, Maryland

NASA Astrophysics Data System (ADS)

Sze, C.; Zaitchik, B. F.; Scott, A.

2015-12-01

Urban regions are often impacted more by heat than adjacent rural areas, which is a phenomenon known as the urban heat island (UHI) effect. Urban areas are also highly heterogeneous and notoriously difficult to monitor using standard meteorological protocols—the hottest microclimates within a city often occur in locations that lack open, representative installation sites that are an adequate distance from buildings and direct heat sources. To investigate the challenges of monitoring urban heat, this study examines the sensitivity of temperature and humidity sensors currently used in a Baltimore UHI monitoring network to differences in sun exposure, material on which the data collecting instrument is attached, and land cover class of the vicinity. Sensitivity to sun exposure and attachment site can be interpreted as sources of uncertainty for urban heat monitoring, while sensitivity to land cover may reflect a true source of local temperature and humidity variability. In this study, we present results from a test deployment designed to assess the sensitivity of heat measurements to each of these three factors. We then apply these results to interpret measurements taken across the entire Baltimore UHI monitoring network. These results can then be used to improve heat measurements and more accurately represent and quantify the UHI effect on a broader scale, such as in neighborhoods or urban centers.

Martian thermal boundary layers: Subhourly variations induced by radiative-conductive heat transfer within the dust-laden atmosphere-ground system

NASA Technical Reports Server (NTRS)

Pallmann, A. J.; Dannevik, W. P.; Frisella, S. P.

1973-01-01

Radiative-conductive heat transfer has been investigated for the ground-atmosphere system of the planet Mars. The basic goal was the quantitative determination of time dependent vertical distributions of temperature and static stability for Southern-Hemispheric summer season and middle and polar latitudes, for both dust-free and dust-laden atmospheric conditions. The numerical algorithm which models at high spatial and temporal resolution the thermal energy transports in the dual ground-atmosphere system, is based on solution of the applicable heating rate equation, including radiative and molecular-conductive heat transport terms. The two subsystems are coupled by an internal thermal boundary condition applied at the ground-atmosphere interface level. Initial data and input parameters are based on Mariner 4, 6, 7, and 9 measurements and the JPL Mars Scientific Model. Numerical experiments were run for dust-free and dust-laden conditions in the midlatitudes, as well as ice-free and ice-covered polar regions. Representative results and their interpretation are presented. Finally, the theoretical framework of the generalized problem with nonconservative Mie scattering and explicit thermal-convective heat transfer is formulated, and applicable solution algorithms are outlined.

Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage

DTIC Science & Technology

2017-03-21

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Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage (EW-201135)

DTIC Science & Technology

2017-03-01

recommendation, or favoring by the Department of Defense. Page Intentionally Left Blank REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704... FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 03-21-2017 2. REPORT TYPE Final Report 3. DATES COVERED (From - To) 09/2011-03/2017 4...91 19b. TELEPHONE NUMBER (include area code) 478-405-8301 Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39.18 Page

Experiments On Transparent Conductive Films For Spacecraft

NASA Technical Reports Server (NTRS)

Perez-Davis, Marla E.; Rutledge, Sharon K.; De Groh, Kim K.; Hung, Ching-Cheh; Malave-Sanabria, Tania; Hambourger, Paul; Roig, David

1995-01-01

Report describes experiments on thin, transparent, electrically conductive films made, variously, of indium tin oxide covered by magnesium fluoride (ITO/MgF2), aluminum-doped zinc oxide (AZO), or pure zinc oxide (ZnO). Films are candidates for application to such spacecraft components, including various optoelectronic devices and window surfaces that must be protected against buildup of static electric charge. On Earth, such films useful on heat mirrors, optoelectronic devices, gas sensors, and automotive and aircraft windows.

Evolution of Heat Flow with Age on the Southern Flank of the Costa Rica Rift

NASA Astrophysics Data System (ADS)

Kolandaivelu, K. P.; Harris, R. N.; Lowell, R. P.; Wilson, D. J.; Hobbs, R. W.

2017-12-01

Analysis of 67 new conductive heat flow measurements at five sites ranging between ≈ 1.6 and 5.7 Ma on the southern flank of the Costa Rica Rift yields insight into factors that influence hydrothermal circulation in young oceanic crust. The heat flow measurements were collocated with a high-resolution multi-channel seismic line, extending from the ridge axis to ODP hole 504B. The mean conductive heat flow, qobs, 80 mWm-2, is ≈ 25% of the mean lithospheric heat flux, qth, predicted by half-space conductive cooling model. The ratio qobs/qth varies significantly from site to site indicating that advective heat loss may be influenced by the presence of high-angle, ridge-ward dipping normal faults, surface topography, and sediment thickness, which vary significantly along the profile. The 1.6 Ma heat flow site, which is located between two outcrops separated by 2 km and has thin sediment cover, yields qobs/qth » 0.08. The advective heat loss indicates a mass flux of 3 x 10-5 kgm-2s-1 and upper crustal permeabilities of 4 x 10-11 and 3 x 10-9 m2 for 1000 m and 100 m aquifer thicknesses, respectively. At the 2.6 Ma site with 75 m sediment cover, qobs/qth » 0.18 and heat flow is uniformly low, except for one high value near a fault. At the 3.5 Ma site, qobs/qth » 0.15. The heat flow deficit results from outcrop to outcrop flow, but subcritical cellular convection driven by local basement topography produces small heat flow highs and lows superimposed on the overall trend. At the 4.5 Ma site, qobs/qth » 0.06. The heat flow distribution indicates that discharge occurs through a large, thinly-sedimented topographical high, where estimated mass flux is 3 x 10-5 kgm-2s-1. At the oldest site of 5.7 Ma, qobs/qth » 1, but some heat flow values greater than qth occur near sparsely-sedimented basement outcrops, suggesting redistribution of heat by subsurface convection controlled by basement topography, similar to ODP Hole 504B. That qobs/qth » 1 at a much younger age than indicated by global data suggests that basement burial under a thick sediment cover inhibits advective heat loss through the crust. These data were collected as part of a major interdisciplinary NERC and NSF-funded collaboration entitled: Oceanographic and Seismic Characterization of heat dissipation and alteration by hydrothermal fluids at an Axial Ridge (OSCAR).

Heat strain and heat stress for workers wearing protective suits at a hazardous waste site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paull, J.M.; Rosenthal, F.S.

1987-05-01

In order to evaluate the effects of heat stress when full body protective suits are worn, heart rates, oral temperatures and environmental parameters were measured for five unacclimatized male workers (25-33 years of age) who performed sampling activities during hazardous waste clean-up operations. The protective ensembles included laminated PVC-Tyvec chemical resistant hood suits with rubber boots, gloves, full facepiece dual cartridge respirators and hard hats. For comparison, measurements also were performed when the men worked at a similar level of activity while they wore ordinary work clothes. A comparison of the heart rates for the men working with and withoutmore » suits indicated that wearing the suits imposed a heat stress equivalent to adding 6/sup 0/ to 11/sup 0/C (11/sup 0/ to 20/sup 0/F) to the ambient WBGT index. A similar result was obtained by calculating the WBGT in the microclimate inside the suits and comparing it to the ambient WBGT. These results indicate the following: 1) there exists a significant risk of heat injury during hazardous waste work when full body protective clothing is worn, and 2) threshold limit values for heat stress established by the ACGIH must be lowered substantially before extending them to cover workers under these conditions.« less

Simulation of Rocket-Grade Kerosene Flowing in an Electrically Heated Experimental Apparatus

DTIC Science & Technology

2015-07-01

Technical Paper 3. DATES COVERED (From - To) July 2015-July 2015 4. TITLE AND SUBTITLE Simulation of Rocket Kerosene Flowing in an Electrically Heated...rocket-grade kerosene (RP-2) flowing in an electrically heated tube is simulated. The model and boundary conditions are selected so as to simulate an...and Astronautics 1 Simulation of Rocket-Grade Kerosene Flowing in an Electrically Heated Experimental Apparatus Ananda Himansu1 and Matthew C

Polaron effects on the performance of light-harvesting systems: a quantum heat engine perspective

NASA Astrophysics Data System (ADS)

Xu, Dazhi; Wang, Chen; Zhao, Yang; Cao, Jianshu

2016-02-01

We explore energy transfer in a generic three-level system, which is coupled to three non-equilibrium baths. Built on the concept of quantum heat engine, our three-level model describes non-equilibrium quantum processes including light-harvesting energy transfer, nano-scale heat transfer, photo-induced isomerization, and photovoltaics in double quantum-dots. In the context of light-harvesting, the excitation energy is first pumped up by sunlight, then is transferred via two excited states which are coupled to a phonon bath, and finally decays to the reaction center. The efficiency of this process is evaluated by steady state analysis via a polaron-transformed master equation; thus the entire range of the system-phonon coupling strength can be covered. We show that the coupling with the phonon bath not only modifies the steady state, resulting in population inversion, but also introduces a finite steady state coherence which optimizes the energy transfer flux and efficiency. In the strong coupling limit, the steady state coherence disappears and the efficiency recovers the heat engine limit given by Scovil and Schultz-Dubois (1959 Phys. Rev. Lett. 2 262).

Forced convective melting at an evolving ice-water interface

NASA Astrophysics Data System (ADS)

Ramudu, Eshwan; Hirsh, Benjamin; Olson, Peter; Gnanadesikan, Anand

2015-11-01

The intrusion of warm Circumpolar Deep Water into the ocean cavity between the base of ice shelves and the sea bed in Antarctica causes melting at the ice shelves' basal surface, producing a turbulent melt plume. We conduct a series of laboratory experiments to investigate how the presence of forced convection (turbulent mixing) changes the delivery of heat to the ice-water interface. We also develop a theoretical model for the heat balance of the system that can be used to predict the change in ice thickness with time. In cases of turbulent mixing, the heat balance includes a term for turbulent heat transfer that depends on the friction velocity and an empirical coefficient. We obtain a new value for this coefficient by comparing the modeled ice thickness against measurements from a set of nine experiments covering one order of magnitude of Reynolds numbers. Our results are consistent with the altimetry-inferred melting rate under Antarctic ice shelves and can be used in climate models to predict their disintegration. This work was supported by NSF grant EAR-110371.

Management of heat in laser tissue welding using NIR cover window material.

PubMed

Sriramoju, Vidyasagar; Savage, Howard; Katz, Alvin; Muthukattil, Ronex; Alfano, Robert R

2011-12-01

Laser tissue welding (LTW) is a novel method of surgical wound closure by the use of laser radiation to induce fusion of the biological tissues. Molecular dynamics associated with LTW is a result of thermal and non-thermal mechanisms. This research focuses exclusively on better heat management to reduce thermal damage of tissues in LTW using a near infrared laser radiation. An infrared continuous-wave (CW) laser radiation at 1,450 nm wavelength corresponding to the absorption band from combination vibrational modes of water is used to weld together ex vivo porcine aorta. In these studies we measured the optimal laser power and scan speed, for better tensile strength of the weld and lesser tissue dehydration. Significant amount of water loss from the welded tissue results in cellular death and tissue buckling. Various thermally conductive optical cover windows were used as heat sinks to reduce thermal effects during LTW for the dissipation of the heat. The optimal use of the method prevents tissue buckling and minimizes the water loss. Diamond, sapphire, BK7, fused silica, and IR quartz transparent optical cover windows were tested. The data from this study suggests that IR-quartz as the material with optimal thermal conductivity is ideal for laser welding of the porcine aorta. Copyright © 2011 Wiley Periodicals, Inc.

Pretest parametric calculations for the heated pillar experiment in the WIPP In-Situ Experimental Area

DOE Office of Scientific and Technical Information (OSTI.GOV)

Branstetter, L.J.

Results are presented for a pretest parametric study of several configurations and heat loads for the heated pillar experiment (Room H) in the Waste Isolation Pilot Plant (WIPP) In Situ Experimental Area. The purpose of this study is to serve as a basis for selection of a final experiment geometry and heat load. The experiment consists of a pillar of undisturbed rock salt surrounded by an excavated annular room. The pillar surface is covered by a blanket heat source which is externally insulated. A total of five thermal and ten structural calculations are described in a four to five yearmore » experimental time frame. Results are presented which include relevant temperature-time histories, deformations, rock salt stress component and effective stress profiles, and maximum stresses in anhydrite layers which are in close proximity to the room. Also included are predicted contours of a conservative post-processed measure of potential salt failure. Observed displacement histories are seen to be highly dependent on pillar and room height, but insensitive to other geometrical variations. The use of a tensile cutoff across slidelines is seen to produce more accurate predictions of anhydrite maximum stress, but to have little effect on rock salt stresses. The potential for salt failure is seen to be small in each case for the time frame of interest, and is only seen at longer times in the center of the room floor.« less

Heating and Ventilating II, 11-3. Military Curriculum Materials for Vocational and Technical Education.

ERIC Educational Resources Information Center

Army Engineer School, Fort Belvoir, VA.

This second course in a four-course series on heating and ventilating for the secondary/postsecondary level is one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. The five lessons in the course cover these topics: (1) Principles of Heating,…

Heat Capacity of Room-Temperature Ionic Liquids: A Critical Review

NASA Astrophysics Data System (ADS)

Paulechka, Yauheni U.

2010-09-01

Experimental data on heat capacity of room-temperature ionic liquids in the liquid state were compiled and critically evaluated. The compilation contains data for 102 aprotic ionic liquids from 63 literature references and covers the period of time from 1998 through the end of February 2010. Parameters of correlating equations for temperature dependence of the heat capacities were developed.

Red but not dead: examining microbial and plant recovery in severely burned soils

Treesearch

Marie Oliver; Jane Smith; Cassie Hebel

2010-01-01

Soil exposed to prolonged intense heat during a wildfire turns a distinctive red color. The heat volatilizes soil nutrients and kills subterranean microbial communities. Patches of severely burned red soil are found most frequently in areas that were heavily covered with down, dead wood before the fire. It has long been thought that exposure to such heat sterilized...

Heating and Ventilating III, 11-4. Military Curriculum Materials for Vocational and Technical Education.

ERIC Educational Resources Information Center

Army Engineer School, Fort Belvoir, VA.

This third course in a four-course series on heating and ventilating for the secondary/postsecondary level is one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. The three lessons in the course cover these topics: (1) Warm-Air Heating, (2)…

Timonium Elementary School Solar Energy Heating and Cooling Augmentation Experiment. Final Engineering Report. Executive Summary.

ERIC Educational Resources Information Center

AAI Corp., Baltimore, MD.

This report covers a two-year and seven-month solar space heating and cooling experiment conducted at the Timonium Elementary School, Timonium, Maryland. The system was designed to provide a minimum of 50 percent of the energy required during the heating season and to determine the feasibility of using solar energy to power absorption-type…

Protrusion of the tongue in bodies burned after death: Two cases of arson to cover homicide.

PubMed

Nikolić, Slobodan; Živković, Vladimir

2015-10-01

In the forensic assessment of burned bodies, the question of whether the victim was exposed to fire before or after death is of crucial importance. Many authors consider tongue protrusion in cases of burned bodies to be a post-mortem phenomenon. Deep-heating effects of fire are sufficient to cook muscle. The muscle becomes shortened by dehydration and protein denaturation. Exposure to heat causes flexion of the extremities on the contraction of muscles and tendons - heat rigour. The flexors, being bulkier than the extensors, contract more and force the limbs into the position of general flexion. The genioglossus is the major muscle of the tongue and is responsible for protruding or sticking out the tongue: by means of its inferior fibres, it draws the root of the tongue forward and protrudes the apex from the mouth. Similar to the action of limb flexors exposed to heat and the appearance of post-mortem general flexion of a burned body due to heat rigour, perhaps the geniglossus could be shortened by heat, causing post-mortem tongue protrusion to appear as heat rigour of the tongue. In this paper, we present two such cases of protrusion of the tongue in bodies burned after death - cases of arson to cover homicide. © The Author(s) 2014.

High Spatial Resolution Thermal Infrared Remote Sensing Data for Analysis of the Atlanta, Georgia, Urban Heat Island Effect and Its Impacts on the Environment

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.

2007-01-01

The twenty-first century is the first "urban century" according to the United Nations Development Program. The focus of cities reflects awareness of the growing percentage of the world's population that lives in urban areas. In environmental terms, cities are the original producers of many of the global problems related to waste disposal, air and water pollution, and associated environmental and ecological challenges. Expansion of cities, both in population and areal extent, is a relentless process. In 2000, approximately 3 billion people representing about 40% of the global population, resided in urban areas. Urban population will continue to rise substantially over the next several decades according to UN estimates, and most of this growth will Occur in developing countries. The UN estimates that by 2025, 60% of the world's population will live in urban areas. As a consequence, the number of"megacities" (those cities with populations of 10 million inhabitants or more) will increase by 100 by 2025. Thus, there is a critical need to understand urban areas and what their impacts are on environmental, ecological and hydrologic resources, as well as on the local, regional, and even global climate. One of the more egregious side effects of urbanization is the increase in surface and air temperatures that lead to deterioration in air quality. In the United States, under the more stringent air quality guidelines established by the U.S. Environmental Protection Agency in 1997, nearly 300 counties in 34 states will not meet these new air quality standards for ground level ozone. Mitigation of the urban heat island (UHI) effect is actively being evaluated as a possible way to reduce ground ozone levels in cities and assist states in improving air quality. Foremost in the analysis of how the UHI affects air quality and other environmental factors is the use of remote sensing technology and data to characterize urban land covers in sufficient detail to quantifiably measure the impact of increased urban heating on air quality. The urban landscape impacts surface thermal energy exchanges that determine development of the UHI. This paper will illustrate how we are using high spatial remote sensing data collected over the Atlanta, Georgia metropolitan area in conjunction with other geographic information, to perform a detailed urban land cover classification and to determine the contribution of these land covers to the urban heat island effect. Also, the spatial arrangement of the land covers and the impact on urban heating from these selected patterns of development are evaluated. Additionally, this paper will show how these data are being used as inputs to improve air quality modeling for Atlanta, including potential benefits from UHI mitigation.

The impact of changing the land surface scheme in ACCESS(v1.0/1.1) on the surface climatology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kowalczyk, Eva A.; Stevens, Lauren E.; Law, Rachel M.

The Community Atmosphere Biosphere Land Exchange (CABLE) model has been coupled to the UK Met Office Unified Model (UM) within the existing framework of the Australian Community Climate and Earth System Simulator (ACCESS), replacing the Met Office Surface Exchange Scheme (MOSES). Here we investigate how features of the CABLE model impact on present-day surface climate using ACCESS atmosphere-only simulations. The main differences attributed to CABLE include a warmer winter and a cooler summer in the Northern Hemisphere (NH), earlier NH spring runoff from snowmelt, and smaller seasonal and diurnal temperature ranges. The cooler NH summer temperatures in canopy-covered regions aremore » more consistent with observations and are attributed to two factors. Firstly, CABLE accounts for aerodynamic and radiative interactions between the canopy and the ground below; this placement of the canopy above the ground eliminates the need for a separate bare ground tile in canopy-covered areas. Secondly, CABLE simulates larger evapotranspiration fluxes and a slightly larger daytime cloud cover fraction. Warmer NH winter temperatures result from the parameterization of cold climate processes in CABLE in snow-covered areas. In particular, prognostic snow density increases through the winter and lowers the diurnally resolved snow albedo; variable snow thermal conductivity prevents early winter heat loss but allows more heat to enter the ground as the snow season progresses; liquid precipitation freezing within the snowpack delays the building of the snowpack in autumn and accelerates snow melting in spring. Altogether we find that the ACCESS simulation of surface air temperature benefits from the specific representation of the turbulent transport within and just above the canopy in the roughness sublayer as well as the more complex snow scheme in CABLE relative to MOSES.« less

The impact of changing the land surface scheme in ACCESS(v1.0/1.1) on the surface climatology

DOE PAGES

Kowalczyk, Eva A.; Stevens, Lauren E.; Law, Rachel M.; ...

2016-08-23

The Community Atmosphere Biosphere Land Exchange (CABLE) model has been coupled to the UK Met Office Unified Model (UM) within the existing framework of the Australian Community Climate and Earth System Simulator (ACCESS), replacing the Met Office Surface Exchange Scheme (MOSES). Here we investigate how features of the CABLE model impact on present-day surface climate using ACCESS atmosphere-only simulations. The main differences attributed to CABLE include a warmer winter and a cooler summer in the Northern Hemisphere (NH), earlier NH spring runoff from snowmelt, and smaller seasonal and diurnal temperature ranges. The cooler NH summer temperatures in canopy-covered regions aremore » more consistent with observations and are attributed to two factors. Firstly, CABLE accounts for aerodynamic and radiative interactions between the canopy and the ground below; this placement of the canopy above the ground eliminates the need for a separate bare ground tile in canopy-covered areas. Secondly, CABLE simulates larger evapotranspiration fluxes and a slightly larger daytime cloud cover fraction. Warmer NH winter temperatures result from the parameterization of cold climate processes in CABLE in snow-covered areas. In particular, prognostic snow density increases through the winter and lowers the diurnally resolved snow albedo; variable snow thermal conductivity prevents early winter heat loss but allows more heat to enter the ground as the snow season progresses; liquid precipitation freezing within the snowpack delays the building of the snowpack in autumn and accelerates snow melting in spring. Altogether we find that the ACCESS simulation of surface air temperature benefits from the specific representation of the turbulent transport within and just above the canopy in the roughness sublayer as well as the more complex snow scheme in CABLE relative to MOSES.« less

Air quality measurements and monitoring network in the Republic of Latvia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grinman, A.; Lyulko, J.; Dubrovskaja, R.

1996-12-31

The territory of Latvia is covered with a wide environmental monitoring network, that falls under 2 main categories: (1) regional network featuring the region and involved in international monitoring programs, including EMEP, GAW, IM; (2) state network providing for local pollution monitoring of the atmosphere (19 posts), precipitation (5 station) and radioactivity (46 station). In 1994, measurements were made at 20 stationary posts located in Daugavpils (2), Jekabpils (2), Jurmala, (2), Liepaja (2), Nigrande (1), Olaine (1), Rezekne (1), Riga (5), Valn-dera (2), Ventspils (2). This atmospheric air observation network covers mostly towns densely populated with industrial objects and othermore » pollutant emitting sources. Thus, the observation programs encompass measurements of pollutants that have higher concentrations in the ambient air. Results indicate that the annual pollution dynamics are closely connected with concentration fluctuations in the seasons. The sulfur dioxide and nitrogen dioxide concentrations increased during the heating season in Jekabpils, Jurmala and Valmiera, i.e., in the town that have many small heating installations. The data obtained allow to trace a dependence of measurement values upon the location of the observational posts vis-a-vis the pollutant emitting sources.« less

Upper tropospheric cloud systems determined from IR Sounders and their influence on the atmosphere

NASA Astrophysics Data System (ADS)

Stubenrauch, Claudia; Protopapadaki, Sofia; Feofilov, Artem; Velasco, Carola Barrientos

2017-02-01

Covering about 30% of the Earth, upper tropospheric clouds play a key role in the climate system by modulating the Earth's energy budget and heat transport. Infrared Sounders reliably identify cirrus down to an IR optical depth of 0.1. Recently LMD has built global cloud climate data records from AIRS and IASI observations, covering the periods from 2003-2015 and 2008-2015, respectively. Upper tropospheric clouds often form mesoscale systems. Their organization and properties are being studied by (1) distinguishing cloud regimes within 2° × 2° regions and (2) applying a spatial composite technique on adjacent cloud pressures, which estimates the horizontal extent of the mesoscale cloud systems. Convective core, cirrus anvil and thin cirrus of these systems are then distinguished by their emissivity. Compared to other studies of tropical mesoscale convective systems our data include also the thinner anvil parts, which make out about 30% of the area of tropical mesoscale convective systems. Once the horizontal and vertical structure of these upper tropospheric cloud systems is known, we can estimate their radiative effects in terms of top of atmosphere and surface radiative fluxes and by computing their heating rates.

Climate change and heat waves in Paris and London metropolitan areas

NASA Astrophysics Data System (ADS)

Dousset, B.

2010-12-01

Summer warming trends in Western and Central Europe and in Mediterranean regions are increasing the incidence, intensity, and duration of heat waves. Those extreme events are especially deadly in large cities, owing to high population densities, surface characteristics, heat island effects, anthropogenic heat and pollutants. In August 2003, a persistent anticyclone over Western Europe generated a heat wave of exceptional strength and duration with an estimated death toll of 70,000, including 4678 in the Paris region. A series of NOAA-AVHRR satellite thermal images over the Paris and London metropolitan areas, were used to analyze Land Surface Temperature (LST) and its related mortality. In the Paris region, LSTs were merged with land use and cover data to identify risk areas, and thermal indicators were produced at the addresses of ~ 500 elderly people to assess diurnal heat exposure. Results indicate: (i) contrasting night time and daytime heat island patterns related to land use and surface characteristics; (ii) the relation between night-time heat islands and heat waves intensity; (iii) the impact of elevated minimal temperatures on excess mortality, with a 0.5 °C increase doubling the risk of death, (in the temperature range of the heatwave); iv) the correlation between the spatial distribution of highest night-time LSTs and that of highest mortality ratios; and v) the significant impact of urban parks in the partitioning between latent and sensible surface heat fluxes, despite a prior warm and dry spring. Near-real time satellite monitoring of heat waves in urban areas improve our understanding of the LST processes and spatial variability, and of the related heat stress and mortality. These observations provide criteria for warning systems, contingency policies and planning, and climate adaptation and mitigation strategies.

Preparation of MgO/B₂O₃ coatings by plasma spraying on SUS304 surface and effects of heat-resistant.

PubMed

Song, Bo; Zhou, Ningning; Ju, Dongying

2013-12-01

This study mainly deals with the preparation of MgO/B2O3 coatings by plasma spraying on the SUS304 surface and the effects of heat-resistant. The power materials of low thermal conductivity were selected to control the heat divergent performance of high temperature parts. The reticular micro-structure between the cover thermal layer and the substrate was prepared by using the plasma spraying method. The powder mixture of MgO and B2O3 were selected as spraying materials and the SUS304 was used as the substrate material. The MgO/B2O3 coating was prepared on the surface of the SUS304 to provide better cover thermal performance. The properties of the microstructures and the morphologies were studied by Optical Microscope, Scanning Electron Microscope, Electron Probe Microanalyzer, and X-ray Diffraction. The results showed that the cover thermal performance has been improved. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

10 CFR 431.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... defined in § 431.12; commercial heating, ventilating, and air conditioning, and water heating product... distributor of the covered equipment being evaluated. ISO means International Organization for Standardization... territory or possession of the United States. State regulation means a law or regulation of a State or...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

A collection of quarterly and monthly reports from Elcam, Inc., covering progress made from January 1, 1978, through September 30, 1978, is presented. Elcam, is developing two solar-heated hot water prototype systems and two heat exchangers. This effort consists of development, manufacture, installation, maintenance, problem resolution, and system evaluation.

Combined Active and Passive Solar Space Heating and Solar Hot Water Systems for an Elementary School in Boise, Idaho.

ERIC Educational Resources Information Center

Smull, Neil A.; Armstrong, Gerald L.

1979-01-01

Amity Elementary School in Boise, Idaho, features a solar space heating and domestic hot water system along with an earth covering to accommodate the passive aspects of energy conservation. (Author/MLF)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourham, Mohamed A.; Gilligan, John G.

Safety considerations in large future fusion reactors like ITER are important before licensing the reactor. Several scenarios are considered hazardous, which include safety of plasma-facing components during hard disruptions, high heat fluxes and thermal stresses during normal operation, accidental energy release, and aerosol formation and transport. Disruption events, in large tokamaks like ITER, are expected to produce local heat fluxes on plasma-facing components, which may exceed 100 GW/m{sup 2} over a period of about 0.1 ms. As a result, the surface temperature dramatically increases, which results in surface melting and vaporization, and produces thermal stresses and surface erosion. Plasma-facing componentsmore » safety issues extends to cover a wide range of possible scenarios, including disruption severity and the impact of plasma-facing components on disruption parameters, accidental energy release and short/long term LOCA's, and formation of airborne particles by convective current transport during a LOVA (water/air ingress disruption) accident scenario. Study, and evaluation of, disruption-induced aerosol generation and mobilization is essential to characterize database on particulate formation and distribution for large future fusion tokamak reactor like ITER. In order to provide database relevant to ITER, the SIRENS electrothermal plasma facility at NCSU has been modified to closely simulate heat fluxes expected in ITER.« less

Numerical Modeling of Coupled Water Flow and Heat Transport in Soil and Snow

NASA Astrophysics Data System (ADS)

Kelleners, T.

2015-12-01

A numerical model is developed to calculate coupled water flow and heat transport in seasonally frozen soil and snow. Both liquid water flow and water vapor flow are included. The effect of dissolved ions on soil water freezing point depression is included by combining an expression for osmotic head with the Clapeyron equation and the van Genuchten soil water retention function. The coupled water flow and heat transport equations are solved using the Thomas algorithm and Picard iteration. Ice pressure is always assumed zero and frost heave is neglected. The new model is tested using data from a high-elevation rangeland soil that is subject to significant soil freezing and a mountainous forest soil that is snow-covered for about 8 months of the year. Soil hydraulic parameters are mostly based on measurements and only vegetation parameters are fine-tuned to match measured and calculated soil water content, soil & snow temperature, and snow height. Modeling statistics for both systems show good performance for temperature, intermediate performance for snow height, and relatively low performance for soil water content, in accordance with earlier results with an older version of the model.

Diagnostic examination of thermally abused high-power lithium-ion cells

NASA Astrophysics Data System (ADS)

Abraham, D. P.; Roth, E. P.; Kostecki, R.; McCarthy, K.; MacLaren, S.; Doughty, D. H.

The inherent thermal instability of lithium-ion cells is a significant impediment to their widespread commercialization for hybrid-electric vehicle applications. Cells containing conventional organic electrolyte-based chemistries are prone to thermal runaway at temperatures around 180 °C. We conducted accelerating rate calorimetry measurements on high-power 18650-type lithium-ion cells in an effort to decipher the sequence of events leading to thermal runaway. In addition, electrode and separator samples harvested from a cell that was heated to 150 °C then air-quenched to room temperature were examined by microscopy, spectroscopy, and diffraction techniques. Self-heating of the cell began at 84 °C. The gases generated in the cell included CO 2 and CO, and smaller quantities of H 2, C 2H 4, CH 4, and C 2H 6. The main changes on cell heating to 150 °C were observed on the anode surface, which was covered by a thick layer of surface deposits that included LiF and inorganic and organo-phosphate compounds. The sources of gas generation and the mechanisms leading to the formation of compounds observed on the electrode surfaces are discussed.

Experimental validation of energy parameters in parabolic trough collector with plain absorber and analysis of heat transfer enhancement techniques

NASA Astrophysics Data System (ADS)

Bilal, F. R.; Arunachala, U. C.; Sandeep, H. M.

2018-01-01

The quantum of heat loss from the receiver of the Parabolic Trough Collector is considerable which results in lower thermal efficiency of the system. Hence heat transfer augmentation is essential which can be attained by various techniques. An analytical model to evaluate the system with bare receiver performance was developed using MATLAB. The experimental validation of the model resulted in less than 5.5% error in exit temperature using both water and thermic oil as heat transfer fluid. Further, heat transfer enhancement techniques were incorporated in the model which included the use of twisted tape inserts, nanofluid, and a combination of both for further enhancement. It was observed that the use of evacuated glass cover in the existing setup would increase the useful heat gain up to 5.3%. Fe3O4/H2O nanofluid showed a maximum enhancement of 56% in the Nusselt number for the volume concentration of 0.6% at highest Reynolds number. Similarly, twisted tape turbulators (with twist ratio of 2) taken alone with water exhibited 59% improvement in Nusselt number. Combining both the heat transfer augmentation techniques at their best values revealed the Nusselt number enhancement up to 87%. It is concluded that, use of twisted tape with water is the best method for heat transfer augmentation since it gives the maximum effective thermal efficiency amongst all for the range of Re considered. The first section in your paper

Development of a microwave clothes dryer. Interim report II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, R.D.; Gerling, J.E.

The objective of the project is to investigate the microwave drying of clothes and to produce a database for use by interested parties, including appliance manufacturers, in designing and developing microwave clothes dryers. This is an interim report covering 1992 activities. Performance of a research model of a microwave dryer was compared to that of a conventional (top-of-the-line) electric dryer. Drying time was reduced by 58%; superior fabric care was demonstrated on fine fabrics because of the low drying temperatures; and efficiency was increased 18%. Microwaves penetrate the clothes and heat the water molecules directly while conventional heat energy mustmore » be conducted through the clothes to heat the water. A flow of heated air conducts the water vapor away from the clothes. Conventional metal buttons and zippers do not heat greatly in the 2,450 MHz microwave field but bobby pins, bread ties and nails heat enough to damage clothes. That heating has been eliminated by switching to the 915-MHz microwave frequency. Metallized threads may still constitute a heating problem. Based upon results from tests of the research model, a prototype has been designed and three units have been constructed. One unit is retained for laboratory testing while the other two will be shipped to two major appliance manufacturers for evaluations in their laboratories. Consumer panels generally liked the high speed, fabric care and improved efficiency of the microwave dryer but were concerned about the higher first cost.« less

Comparison of forced-air warming systems with upper body blankets using a copper manikin of the human body.

PubMed

Bräuer, A; English, M J M; Steinmetz, N; Lorenz, N; Perl, T; Braun, U; Weyland, W

2002-09-01

Forced-air warming with upper body blankets has gained high acceptance as a measure for the prevention of intraoperative hypothermia. However, data on heat transfer with upper body blankets are not yet available. This study was conducted to determine the heat transfer efficacy of eight complete upper body warming systems and to gain more insight into the principles of forced-air warming. Heat transfer of forced-air warmers can be described as follows: Qdot;=h. DeltaT. A, where Qdot;= heat flux [W], h=heat exchange coefficient [W m-2 degrees C-1], DeltaT=temperature gradient between the blanket and surface [ degrees C], and A=covered area [m2]. We tested eight different forced-air warming systems: (1) Bair Hugger and upper body blanket (Augustine Medical Inc. Eden Prairie, MN); (2) Thermacare and upper body blanket (Gaymar Industries, Orchard Park, NY); (3) Thermacare (Gaymar Industries) with reusable Optisan upper body blanket (Willy Rüsch AG, Kernen, Germany); (4) WarmAir and upper body blanket (Cincinnati Sub-Zero Products, Cincinnati, OH); (5) Warm-Gard and single use upper body blanket (Luis Gibeck AB, Upplands Väsby, Sweden); (6) Warm-Gard and reusable upper body blanket (Luis Gibeck AB); (7) WarmTouch and CareDrape upper body blanket (Mallinckrodt Medical Inc., St. Luis, MO); and (8) WarmTouch and reusable MultiCover trade mark upper body blanket (Mallinckrodt Medical Inc.) on a previously validated copper manikin of the human body. Heat flux and surface temperature were measured with 11 calibrated heat flux transducers. Blanket temperature was measured using 11 thermocouples. The temperature gradient between the blanket and surface (DeltaT) was varied between -8 and +8 degrees C, and h was determined by linear regression analysis as the slope of DeltaT vs. heat flux. Mean DeltaT was determined for surface temperatures between 36 and 38 degrees C, as similar mean skin surface temperatures have been found in volunteers. The covered area was estimated to be 0.35 m2. Total heat flow from the blanket to the manikin was different for surface temperatures between 36 and 38 degrees C. At a surface temperature of 36 degrees C the heat flows were higher (4-26.6 W) than at surface temperatures of 38 degrees C (2.6-18.1 W). The highest total heat flow was delivered by the WarmTouch trade mark system with the CareDrape trade mark upper body blanket (18.1-26.6 W). The lowest total heat flow was delivered by the Warm-Gard system with the single use upper body blanket (2.6-4 W). The heat exchange coefficient varied between 15.1 and 36.2 W m-2 degrees C-1, and mean DeltaT varied between 0.5 and 3.3 degrees C. We found total heat flows of 2.6-26.6 W by forced-air warming systems with upper body blankets. However, the changes in heat balance by forced-air warming systems with upper body blankets are larger, as these systems are not only transferring heat to the body but are also reducing heat losses from the covered area to zero. Converting heat losses of approximately 37.8 W to heat gain, results in a 40.4-64.4 W change in heat balance. The differences between the systems result from different heat exchange coefficients and different mean temperature gradients. However, the combination of a high heat exchange coefficient with a high mean temperature gradient is rare. This fact offers some possibility to improve these systems.

The energy crisis and energy from the sun; Proceedings of the Symposium on Solar Energy Utilization, Washington, D.C., April 30, 1974

NASA Technical Reports Server (NTRS)

Thekaekara, M. P.

1974-01-01

Papers on the state of the art and future prospects of solar energy utilization in the United States are included. Research and technologies for heating and cooling of buildings, solar thermal energy conversion, photovoltaic conversion, biomass production and conversion, wind energy conversion and ocean thermal energy conversion are covered. The increasing funding of the National Solar Energy Program is noted. Individual items are announced in this issue.

Mechanisms of HSP72 release.

PubMed

Asea, Alexzander

2007-04-01

Currently two mechanisms are recognized by which heat shock proteins (HSP) are released from cells; a passive release mechanism, including necrotic cell death, severe blunt trauma, surgery and following infection with lytic viruses, and an active release mechanism which involves the non classical protein release pathway. HSPs are released both as free HSP and within exosomes. This review covers recent findings on the mechanism by which stress induces the release of HSP72 into the circulation and the biological significance of circulating HSP72 to host defense against disease.

Understanding land use change impacts on microclimate using Weather Research and Forecasting (WRF) model

DOE PAGES

Li, Xia; Mitra, Chandana; Dong, Li; ...

2017-02-02

In order to explore potential climatic consequences of land cover change in the Kolkata Metropolitan Development area, we projected microclimate conditions in this area using the Weather Research and Forecasting (WRF) model driven by future land use scenarios. Specifically, we considered two land conversion scenarios including an urbanization scenario that all the wetlands and croplands would be converted to built-up areas, and an irrigation expansion scenario in which all wetlands and dry croplands would be replaced by irrigated croplands. Our results indicated that land use and land cover (LULC) change would dramatically increase regional temperature in this area under themore » urbanization scenario, but expanded irrigation tended to have a cooling effect. In the urbanization scenario, precipitation center tended to move eastward and lead to increased rainfall in eastern parts of this region. Increased irrigation stimulated rainfall in central and eastern areas but reduced rainfall in southwestern and northwestern parts of the study area. Our study also demonstrated that urbanization significantly reduced latent heat fluxes and albedo of land surface; while increased sensible heat flux changes following urbanization suggested that developed land surfaces mainly acted as heat sources. In this study, climate change projection not only predicts future spatiotemporal patterns of multiple climate factors, but also provides valuable insights into policy making related to land use management, water resource management, and agriculture management to adapt and mitigate future climate changes in this populous region.« less

Understanding land use change impacts on microclimate using Weather Research and Forecasting (WRF) model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xia; Mitra, Chandana; Dong, Li

In order to explore potential climatic consequences of land cover change in the Kolkata Metropolitan Development area, we projected microclimate conditions in this area using the Weather Research and Forecasting (WRF) model driven by future land use scenarios. Specifically, we considered two land conversion scenarios including an urbanization scenario that all the wetlands and croplands would be converted to built-up areas, and an irrigation expansion scenario in which all wetlands and dry croplands would be replaced by irrigated croplands. Our results indicated that land use and land cover (LULC) change would dramatically increase regional temperature in this area under themore » urbanization scenario, but expanded irrigation tended to have a cooling effect. In the urbanization scenario, precipitation center tended to move eastward and lead to increased rainfall in eastern parts of this region. Increased irrigation stimulated rainfall in central and eastern areas but reduced rainfall in southwestern and northwestern parts of the study area. Our study also demonstrated that urbanization significantly reduced latent heat fluxes and albedo of land surface; while increased sensible heat flux changes following urbanization suggested that developed land surfaces mainly acted as heat sources. In this study, climate change projection not only predicts future spatiotemporal patterns of multiple climate factors, but also provides valuable insights into policy making related to land use management, water resource management, and agriculture management to adapt and mitigate future climate changes in this populous region.« less

Understanding land use change impacts on microclimate using Weather Research and Forecasting (WRF) model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xia; Mitra, Chandana; Dong, Li

To explore potential climatic consequences of land cover change in the Kolkata Metropolitan Development area, we projected microclimate conditions in this area using the Weather Research and Forecasting (WRF) model driven by future land use scenarios. Specifically, we considered two land conversion scenarios including an urbanization scenario that all the wetlands and croplands would be converted to built-up areas, and an irrigation expansion scenario in which all wetlands and dry croplands would be replaced by irrigated croplands. Results indicated that land use and land cover (LULC) change would dramatically increase regional temperature in this area under the urbanization scenario, butmore » expanded irrigation tended to have a cooling effect. In the urbanization scenario, precipitation center tended to move eastward and lead to increased rainfall in eastern parts of this region. Increased irrigation stimulated rainfall in central and eastern areas but reduced rainfall in southwestern and northwestern parts of the study area. This study also demonstrated that urbanization significantly reduced latent heat fluxes and albedo of land surface; while increased sensible heat flux changes following urbanization suggested that developed land surfaces mainly acted as heat sources. In this study, climate change projection not only predicts future spatiotemporal patterns of multiple climate factors, but also provides valuable insights into policy making related to land use management, water resource management, and agriculture management to adapt and mitigate future climate changes in this populous region. (C) 2017 Elsevier Ltd. All rights reserved.« less

A physically based analytical spatial air temperature and humidity model

NASA Astrophysics Data System (ADS)

Yang, Yang; Endreny, Theodore A.; Nowak, David J.

2013-09-01

Spatial variation of urban surface air temperature and humidity influences human thermal comfort, the settling rate of atmospheric pollutants, and plant physiology and growth. Given the lack of observations, we developed a Physically based Analytical Spatial Air Temperature and Humidity (PASATH) model. The PASATH model calculates spatial solar radiation and heat storage based on semiempirical functions and generates spatially distributed estimates based on inputs of topography, land cover, and the weather data measured at a reference site. The model assumes that for all grids under the same mesoscale climate, grid air temperature and humidity are modified by local variation in absorbed solar radiation and the partitioning of sensible and latent heat. The model uses a reference grid site for time series meteorological data and the air temperature and humidity of any other grid can be obtained by solving the heat flux network equations. PASATH was coupled with the USDA iTree-Hydro water balance model to obtain evapotranspiration terms and run from 20 to 29 August 2010 at a 360 m by 360 m grid scale and hourly time step across a 285 km2 watershed including the urban area of Syracuse, NY. PASATH predictions were tested at nine urban weather stations representing variability in urban topography and land cover. The PASATH model predictive efficiency R2 ranged from 0.81 to 0.99 for air temperature and 0.77 to 0.97 for dew point temperature. PASATH is expected to have broad applications on environmental and ecological models.

Active thermography and post-processing image enhancement for recovering of abraded and paint-covered alphanumeric identification marks

NASA Astrophysics Data System (ADS)

Montanini, R.; Quattrocchi, A.; Piccolo, S. A.

2016-09-01

Alphanumeric marking is a common technique employed in industrial applications for identification of products. However, the realised mark can undergo deterioration, either by extensive use or voluntary deletion (e.g. removal of identification numbers of weapons or vehicles). For recovery of the lost data many destructive or non-destructive techniques have been endeavoured so far, which however present several restrictions. In this paper, active infrared thermography has been exploited for the first time in order to assess its effectiveness in restoring paint covered and abraded labels made by means of different manufacturing processes (laser, dot peen, impact, cold press and scribe). Optical excitation of the target surface has been achieved using pulse (PT), lock-in (LT) and step heating (SHT) thermography. Raw infrared images were analysed with a dedicated image processing software originally developed in Matlab™, exploiting several methods, which include thermographic signal reconstruction (TSR), guided filtering (GF), block guided filtering (BGF) and logarithmic transformation (LN). Proper image processing of the raw infrared images resulted in superior contrast and enhanced readability. In particular, for deeply abraded marks, good outcomes have been obtained by application of logarithmic transformation to raw PT images and block guided filtering to raw phase LT images. With PT and LT it was relatively easy to recover labels covered by paint, with the latter one providing better thermal contrast for all the examined targets. Step heating thermography never led to adequate label identification instead.

Urban Forest Ecosystem Service Optimization, Tradeoffs, and Disparities

NASA Astrophysics Data System (ADS)

Bodnaruk, E.; Kroll, C. N.; Endreny, T. A.; Hirabayashi, S.; Yang, Y.

2014-12-01

Urban land area and the proportion of humanity living in cities is growing, leading to increased urban air pollution, temperature, and stormwater runoff. These changes can exacerbate respiratory and heat-related illnesses and affect ecosystem functioning. Urban trees can help mitigate these threats by removing air pollutants, mitigating urban heat island effects, and infiltrating and filtering stormwater. The urban environment is highly heterogeneous, and there is no tool to determine optimal locations to plant or protect trees. Using spatially explicit land cover, weather, and demographic data within biophysical ecosystem service models, this research expands upon the iTree urban forest tools to produce a new decision support tool (iTree-DST) that will explore the development and impacts of optimal tree planting. It will also heighten awareness of environmental justice by incorporating the Atkinson Index to quantify disparities in health risks and ecosystem services across vulnerable and susceptible populations. The study area is Baltimore City, a location whose urban forest and environmental justice concerns have been studied extensively. The iTree-DST is run at the US Census block group level and utilizes a local gradient approach to calculate the change in ecosystem services with changing tree cover across the study area. Empirical fits provide ecosystem service gradients for possible tree cover scenarios, greatly increasing the speed and efficiency of the optimization procedure. Initial results include an evaluation of the performance of the gradient method, optimal planting schemes for individual ecosystem services, and an analysis of tradeoffs and synergies between competing objectives.

Plant engineers solar energy handbook. [Includes glossaries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1978-01-21

This handbook is to provide plant engineers with factual information on solar energy technology and on the various methods for assessing the future potential of this alternative energy source. The following areas are covered: solar components and systems (collectors, storage, service hot-water systems, space heating with liquid and air systems, space cooling, heat pumps and controls); computer programs for system optimization local solar and weather data; a description of buildings and plants in the San Francisco Bay Area applying solar technology; current Federal and California solar legislation; standards, codes, and performance testing information; a listing of manufacturers, distributors, and professionalmore » services that are available in Northern California; and information access. Finally, solar design checklists are provided for those engineers who wish to design their own systems. (MHR)« less

Modeling Studies of the Effects of Winds and Heat Flux on the Tropical Oceans

NASA Technical Reports Server (NTRS)

Seager, R.

1999-01-01

Over a decade ago, funding from this NASA grant supported the development of the Cane-Zebiak ENSO prediction model which remains in use to this day. It also supported our work developing schemes for modeling the air-sea heat flux in ocean models used for studying climate variability. We introduced a succession of simple boundary layer models that allow the fluxes to be computed internally in the model and avoid the need to specify the atmospheric thermodynamic state. These models have now reached a level of generality that allows modeling of the global, rather than just tropical, ocean, including sea ice cover. The most recent versions of these boundary layer models have been widely distributed around the world and are in use by many ocean modeling groups.

Role of fuel chemical properties on combustor radiative heat load

NASA Technical Reports Server (NTRS)

Rosfjord, T. J.

1984-01-01

In an attempt to rigorously study the fuel chemical property influence on combustor radiative heat load, United Technologies Research Center (UTRC) has conducted an experimental program using 25 test fuels. The burner was a 12.7-cm dia cylindrical device fueled by a single pressure-atomizing injector. Fuel physical properties were de-emphasized by selecting injectors which produced high-atomized, and hence rapidly-vaporizing sprays. The fuels were specified to cover the following wide ranges of chemical properties; hydrogen, 9.1 to 15- (wt) pct; total aromatics, 0 to 100 (vol) pct; and naphthalene, 0 to 30 (vol) pct. They included standard fuels, specialty products and fuel blends. Fuel naphthalene content exhibited the strongest influence on radiation of the chemical properties investigated. Smoke point was a good global indicator of radiation severity.

Factors which influence the development of a low-level jet and coastal cyclogenesis

NASA Technical Reports Server (NTRS)

Uccellini, Louis W.; Petersen, Ralph A.; Kocin, Paul J.; Brill, Keith F.; Tuccillo, James J.

1986-01-01

Mesoscale model simulations were run to examine the mechanisms which generate a low-level jet (LLJ) and the sea-level pressure decrease (SLPD) associated with secondary cyclogenesis along the East Coast of the U.S. Data collected during the Presidents' Day cyclone of February 18-19, 1979 are reviewed, including the behavior of the LLJ preceding cyclogenesis. The simulations covered adiabatic conditions, the absence and presence of latent heating, and the inclusion of all physical parameters with and without computations of boundary layer phenomena, 60-km grid-scale precipitation, and convective precipitation. The results indicate that synergistic reactions among the LLJ, latent heat release, jet-induced circulation, and boundary layer processes are necessary to account for secondary cyclogenesis and the accompanying rapidly evolving mass, momentum and moisture fields.

Temperature and heat flux scaling laws for isoviscous, infinite Prandtl number mixed heating convection

NASA Astrophysics Data System (ADS)

Vilella, Kenny; Deschamps, Frédéric

2018-07-01

Thermal evolution of terrestrial planets is controlled by heat transfer through their silicate mantles. A suitable framework for modelling this heat transport is a system including bottom heating (from the core) and internal heating, for example, generated by secular cooling or by the decay of radioactive isotopes. The mechanism of heat transfer depends on the physical properties of the system. In systems where convection is able to operate, two different regimes are possible depending on the relative amount of bottom and internal heating. For moderate internal heating rates, the system is composed of active hot upwellings and cold downwellings. For large internal heating rates, the bottom heat flux becomes negative and the system is only composed of active cold downwellings. Here, we build theoretical scaling laws for both convective regimes following the approach of Vilella & Kaminski (2017), which links the surface heat flux and the temperature jump across both the top and the bottom thermal boundary layer (TBL) to the Rayleigh number and the dimensionless internal heating rate. Theoretical predictions are then verified against numerical simulations performed in 2-D and 3-D Cartesiangeometry, and covering a large range of the parameter space. Our theoretical scaling laws are more successful in predicting the thermal structure of systems with large internal heating rates than that of systems with no or moderate internal heating. The differences between moderate and large internal heating rates are interpreted as differences in the mechanisms generating thermal instabilities. We identified three mechanisms: conductive growth of the TBL, instability impacting, and TBL erosion, the last two being present only for moderate internal heating rates, in which hot plumes are generated at the bottom of the system and are able to reach the surface. Finally, we apply our scaling laws to the evolution of the early Earth, proposing a new model for the cooling of the primordial magma ocean that reconciles geochemical observations and magma ocean dynamics.

Temperature and heat flux scaling laws for isoviscous, infinite Prandtl number mixed heating convection.

NASA Astrophysics Data System (ADS)

Vilella, Kenny; Deschamps, Frederic

2018-04-01

Thermal evolution of terrestrial planets is controlled by heat transfer through their silicate mantles. A suitable framework for modelling this heat transport is a system including bottom heating (from the core) and internal heating, e.g., generated by secular cooling or by the decay of radioactive isotopes. The mechanism of heat transfer depends on the physical properties of the system. In systems where convection is able to operate, two different regimes are possible depending on the relative amount of bottom and internal heating. For moderate internal heating rates, the system is composed of active hot upwellings and cold downwellings. For large internal heating rates, the bottom heat flux becomes negative and the system is only composed of active cold downwellings. Here, we build theoretical scaling laws for both convective regimes following the approach of Vilella & Kaminski (2017), which links the surface heat flux and the temperature jump across both the top and bottom thermal boundary layer (TBL) to the Rayleigh number and the dimensionless internal heating rate. Theoretical predictions are then verified against numerical simulations performed in 2D and 3D-Cartesian geometry, and covering a large range of the parameter space. Our theoretical scaling laws are more successful in predicting the thermal structure of systems with large internal heating rates than that of systems with no or moderate internal heating. The differences between moderate and large internal heating rates are interpreted as differences in the mechanisms generating thermal instabilities. We identified three mechanisms: conductive growth of the TBL, instability impacting, and TBL erosion, the last two being present only for moderate internal heating rates, in which hot plumes are generated at the bottom of the system and are able to reach the surface. Finally, we apply our scaling laws to the evolution of the early Earth, proposing a new model for the cooling of the primordial magma ocean that reconciles geochemical observations and magma ocean dynamics.

Subcooled forced convection boiling of trichlorotrifluoroethane

NASA Technical Reports Server (NTRS)

Dougall, R. S.; Panian, D. J.

1972-01-01

Experimental heat-transfer data were obtained for the forced-convection boiling of trichlorotrifluoroethane (R-113 or Freon-113) in a vertical annular test annular test section. The 97 data points obtained covered heat transfer by forced convection, local boiling, and fully-developed boiling. Correlating methods were obtained which accurately predicted the heat flux as a function of wall superheat (boiling curve) over the range of parameters studied.

49 CFR Appendix B to Part 238 - Test Methods and Performance Criteria for the Flammability and Smoke Emission Characteristics of...

Code of Federal Regulations, 2012 CFR

2012-10-01

... Flammability of Flexible Cellular Materials Using a Radiant Heat Energy Source. (v) ASTM E 119-00a, Standard... Method for Surface Flammability of Materials Using a Radiant Heat Energy Source. (vii) ASTM E 648-00, Standard Test Method for Critical Radiant Flux of Floor-Covering Systems Using a Radiant Heat Energy Source...

49 CFR Appendix B to Part 238 - Test Methods and Performance Criteria for the Flammability and Smoke Emission Characteristics of...

Code of Federal Regulations, 2013 CFR

2013-10-01

... Flammability of Flexible Cellular Materials Using a Radiant Heat Energy Source. (v) ASTM E 119-00a, Standard... Method for Surface Flammability of Materials Using a Radiant Heat Energy Source. (vii) ASTM E 648-00, Standard Test Method for Critical Radiant Flux of Floor-Covering Systems Using a Radiant Heat Energy Source...

49 CFR Appendix B to Part 238 - Test Methods and Performance Criteria for the Flammability and Smoke Emission Characteristics of...

Code of Federal Regulations, 2011 CFR

2011-10-01

... Flammability of Flexible Cellular Materials Using a Radiant Heat Energy Source. (v) ASTM E 119-00a, Standard... Method for Surface Flammability of Materials Using a Radiant Heat Energy Source. (vii) ASTM E 648-00, Standard Test Method for Critical Radiant Flux of Floor-Covering Systems Using a Radiant Heat Energy Source...

49 CFR Appendix B to Part 238 - Test Methods and Performance Criteria for the Flammability and Smoke Emission Characteristics of...

Code of Federal Regulations, 2014 CFR

2014-10-01

... Flammability of Flexible Cellular Materials Using a Radiant Heat Energy Source. (v) ASTM E 119-00a, Standard... Method for Surface Flammability of Materials Using a Radiant Heat Energy Source. (vii) ASTM E 648-00, Standard Test Method for Critical Radiant Flux of Floor-Covering Systems Using a Radiant Heat Energy Source...

The Mystery of Io's Warm Polar Regions: Implications for Heat Flow

NASA Technical Reports Server (NTRS)

Matson, D. L.; Veeder, G. J.; Johnson, T. V.; Blaney, D. L.; Davies, A. G.

2002-01-01

Unexpectedly warm polar temperatures further support the idea that Io is covered virtually everywhere by cooling lava flows. This implies a new heat flow component. Io's heat flow remains constrained between a lower bound of (approximately) 2.5 W m(exp -2) and an upper bound of (approximately) 13 W m(exp -2). Additional information is contained in the original extended abstract.

Contamination sampling device

NASA Technical Reports Server (NTRS)

Delgado, Felix A. (Inventor); Stern, Susan M. (Inventor)

1998-01-01

A contamination sample collection device has a wooden dowel with a cotton swab at one end, the cotton being covered by a nylon cloth and the wooden dowel being encapsulated by plastic tubing which is heat shrunk onto the dowel and onto a portion of the cotton swab to secure the cotton in place. Another plastic tube is heat shrunk onto the plastic that encapsulates the dowel and a portion of the nylon cloth to secure the nylon cloth in place. The device may thereafter be covered with aluminum foil protector. The device may be used for obtaining samples of contamination in clean room environments.

Evapotranspiration Cycles in a High Latitude Agroecosystem: Potential Warming Role

PubMed Central

Ruairuen, Watcharee

2015-01-01

As the acreages of agricultural lands increase, changes in surface energetics and evapotranspiration (ET) rates may arise consequently affecting regional climate regimes. The objective of this study was to evaluate summertime ET dynamics and surface energy processes in a subarctic agricultural farm in Interior Alaska. The study includes micrometeorological and hydrological data. Results covering the period from June to September 2012 and 2013 indicated consistent energy fractions: LE/R net (67%), G/R net (6%), H/R net (27%) where LE is latent heat flux, R net is the surface net radiation, G is ground heat flux and H is the sensible heat flux. Additionally actual surface evapotranspiration from potential evaporation was found to be in the range of 59 to 66%. After comparing these rates with those of most prominent high latitude ecosystems it is argued here that if agroecosystem in high latitudes become an emerging feature in the land-use, the regional surface energy balance will significantly shift in comparison to existing Arctic natural ecosystems. PMID:26368123

Evapotranspiration Cycles in a High Latitude Agroecosystem: Potential Warming Role.

PubMed

Ruairuen, Watcharee; Fochesatto, Gilberto J; Sparrow, Elena B; Schnabel, William; Zhang, Mingchu; Kim, Yongwon

2015-01-01

As the acreages of agricultural lands increase, changes in surface energetics and evapotranspiration (ET) rates may arise consequently affecting regional climate regimes. The objective of this study was to evaluate summertime ET dynamics and surface energy processes in a subarctic agricultural farm in Interior Alaska. The study includes micrometeorological and hydrological data. Results covering the period from June to September 2012 and 2013 indicated consistent energy fractions: LE/Rnet (67%), G/Rnet (6%), H/Rnet (27%) where LE is latent heat flux, Rnet is the surface net radiation, G is ground heat flux and H is the sensible heat flux. Additionally actual surface evapotranspiration from potential evaporation was found to be in the range of 59 to 66%. After comparing these rates with those of most prominent high latitude ecosystems it is argued here that if agroecosystem in high latitudes become an emerging feature in the land-use, the regional surface energy balance will significantly shift in comparison to existing Arctic natural ecosystems.

Design Construction and Operation of a Supercritical Carbon Dioxide (sCO 2) Loop for Investigation of Dry Cooling and Natural Circulation Potential for Use in Advanced Small Modular Reactors Utilizing sCO 2 Power Conversion Cycles.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Middleton, Bobby D.; Rodriguez, Salvador B.; Carlson, Matthew David

This report outlines the work completed for a Laboratory Directed Research and Development project at Sandia National Laboratories from October 2012 through September 2015. An experimental supercritical carbon dioxide (sCO 2 ) loop was designed, built, and o perated. The experimental work demonstrated that sCO 2 can be uti lized as the working fluid in an air - cooled, natural circulation configuration to transfer heat from a source to the ultimate heat sink, which is the surrounding ambient environment in most ca ses. The loop was also operated in an induction - heated, water - cooled configuration that allows formore » measurements of physical parameters that are difficult to isolate in the air - cooled configuration. Analysis included the development of two computational flu id dynamics models. Future work is anticipated to answer questions that were not covered in this project.« less

Synthetic-rubber extrusions form low cost roll-on solar collector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smay, V.E.

1979-06-01

Synthetic rubber extrusions composed of ethylene propylene diene monomer (EPDM) have been developed in 4.4-inch-wide mats as solar absorbers that are light weight and simple to install. The mats, which come in rolls up to 600 ft long, have 6 small tubes alternating with thin webbing. EPDM has a lifespan of 30-50 yrs and maintains its flexibility within a temperature range of -80 to 375/sup 0/F. The mats are laid over rigid insulation and covered with glazing, detailed assembly instructions are provided. EPDM is not subject to corrosion and is not damaged by freezing water, a second EPDM extrusion ismore » used for glazed solar collectors. The efficiency of the design is attributed to the greater surface-to-mass ratio, permitting more heat collection, and the smaller mass of the synthetic rubber, which allows faster heat-up. The total cost for a complete, installed solar heating system of this type, including pumps, tanks, and plumbing, is about $12/ft/sup 2/.« less

30 CFR 56.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... anticipated, will ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat... covering is one means for making the conductor insulated. Insulation means a dielectric substance offering... flammable vapors when subjected to fire or heat. Concrete, masonry block, brick, and steel are examples of...

Effects of the inclination angle on the performance of flat plate solar collector

NASA Astrophysics Data System (ADS)

Ambarita, H.; Siregar, R. E. T.; Ronowikarto, A. D.; Setyawan, E. Y.

2018-03-01

Double glasses cover is typically used in a flat plate solar collector to decrease heat losses to ambient. The working principal of the cover is to allow the solar irradiation hit the plate absorber and blocks it using natural convection mechanism in the enclosure between the glasses. The performance of the enclosure to block the heat loss to the surrounding affected by the inclination angle of the collector. The objective of this study is to explore the effect of the inclination angle to the performance of the solar collector. Numerical simulation using commercial code Computational Fluid Dynamic (CFD) has been carried out to explore the fluid flow and heat transfer characteristics in the enclosure. In the result, streamline, vector velocity, and contour temperature are plotted. It was shown that the inclination angle strongly affects the performance of the collector. The average heat transfer coefficient decreases with increasing inclination angle. This fact suggests that too high inclination angle is not recommended for solar collector.

Chemical heat pump

DOEpatents

Greiner, Leonard

1980-01-01

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer. The heat pump part of the system heats or cools a house or other structure through a combination of evaporation and absorption or, conversely, condensation and desorption, in a pair of containers. A set of automatic controls change the system for operation during winter and summer months and for daytime and nighttime operation to satisfactorily heat and cool a house during an entire year. The absorber chamber is subjected to solar heating during regeneration cycles and is covered by one or more layers of glass or other transparent material. Daytime home air used for heating the home is passed at appropriate flow rates between the absorber container and the first transparent cover layer in heat transfer relationship in a manner that greatly reduce eddies and resultant heat loss from the absorbant surface to ambient atmosphere.

The Urban Heat Island Impact in Consideration of Spatial Pattern of Urban Landscape and Structure

NASA Astrophysics Data System (ADS)

Kim, J.; Lee, D. K.; Jeong, W.; Sung, S.; Park, J.

2015-12-01

Preceding study has established a clear relationship between land surface temperature and area of land covers. However, only few studies have specifically examined the effects of spatial patterns of land covers and urban structure. To examine how much the local climate is affected by the spatial pattern in highly urbanized city, we investigated the correlation between land surface temperature and spatial patterns of land covers. In the analysis of correlation, we categorized urban structure to four different land uses: Apartment residential area, low rise residential area, industrial area and central business district. Through this study, we aims to examine the types of residential structure and land cover pattern for reducing urban heat island and sustainable development. Based on land surface temperature, we investigated the phenomenon of urban heat island through using the data of remote sensing. This study focused on Daegu in Korea. This city, one of the hottest city in Korea has basin form. We used high-resolution land cover data and land surface temperature by using Landsat8 satellite image to examine 100 randomly selected sample sites of 884.15km2 (1)In each land use, we quantified several landscape-levels and class-level landscape metrics for the sample study sites. (2)In addition, we measured the land surface temperature in 3 year hot summer seasons (July to September). Then, we investigated the pattern of land surface temperature for each land use through Ecognition package. (3)We deducted the Pearson correlation coefficients between land surface temperature and each landscape metrics. (4)We analyzed the variance among the four land uses. (5)Using linear regression, we determined land surface temperature model for each land use. (6)Through this analysis, we aims to examine the best pattern of land cover and artificial structure for reducing urban heat island effect in highly urbanized city. The results of linear regression showed that proportional land cover of grass, tree, water and impervious surfaces well explained the temperature in apartment residential areas. In contrast, the changes in the pattern of water, grass, tree and impervious surfaces were the best to determine the temperature in low rise residential area, central business district and industrial area.

Supersonic/Hypersonic Laminar Heating Correlations for Rectangular and Impact-Induced Open and Closed Cavities

NASA Technical Reports Server (NTRS)

Everhart, Joel L.

2008-01-01

Impact and debris damage to the Space Shuttle Orbiter Thermal Protection System tiles is a random phenomenon, occurring at random locations on the vehicle surface, resulting in random geometrical shapes that are exposed to a definable range of surface flow conditions. In response to the 2003 Final Report of the Columbia Accident Investigation Board, wind tunnel aeroheating experiments approximating a wide range of possible damage scenarios covering both open and closed cavity flow conditions were systematically tested in hypersonic ground based facilities. These data were analyzed and engineering assessment tools for damage-induced fully-laminar heating were developed and exercised on orbit. These tools provide bounding approximations for the damaged-surface heating environment. This paper presents a further analysis of the baseline, zero-pressure-gradient, idealized, rectangular-geometry cavity heating data, yielding new laminar correlations for the floor-averaged heating, peak cavity endwall heating, and the downstream decay rate. Correlation parameters are derived in terms of cavity geometry and local flow conditions. Prediction Limit Uncertainty values are provided at the 95%, 99% and 99.9% levels of significance. Non-baseline conditions, including non-rectangular geometries and flows with known pressure gradients, are used to assess the range of applicability of the new correlations. All data variations fall within the 99% Prediction Limit Uncertainty bounds. Importantly, both open-flow and closed-flow cavity heating are combined into a single-curve parameterization of the heating predictions, and provide a concise mathematical model of the laminar cavity heating flow field with known uncertainty.

Vacuum packaging of InGaAs focal plane array with four-stage thermoelectric cooler

NASA Astrophysics Data System (ADS)

Mo, De-feng; Liu, Da-fu; Yang, Li-yi; Xu, Qin-fei; Li, Xue

2013-09-01

The InGaAs focal plane array (FPA) detectors, covering the near-infrared 1~2.4 μm wavelength range, have been developed for application in space-based spectroscopy of the Earth atmosphere. This paper shows an all-metal vacuum package design for area array InGaAs detector of 1024×64 pixels, and its architecture will be given. Four-stage thermoelectric cooler (TEC) is used to cool down the FPA chip. To acquire high heat dissipation for TEC's Joule-heat, tungsten copper (CuW80) and kovar (4J29) is used as motherboard and cavity material respectively which joined by brazing. The heat loss including conduction, convection and radiation is analyzed. Finite element model is established to analyze the temperature uniformity of the chip substrate which is made of aluminum nitride (AlN). The performance of The TEC with and without heat load in vacuum condition is tested. The results show that the heat load has little influence to current-voltage relationship of TEC. The temperature difference (ΔT) increases as the input current increases. A linear relationship exists between heat load and ΔT of the TEC. Theoretical analysis and calculation show that the heat loss of radiation and conduction is about 187 mW and 82 mW respectively. Considering the Joule-heat of readout circuit and the heat loss of radiation and conduction, the FPA for a 220 K operation at room temperature can be achieved. As the thickness of AlN chip substrate is thicker than 1 millimeter, the temperature difference can be less than 0.3 K.

Design and Testing of a Thermal Storage System for Electric Vehicle Cabin Heating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Mingyu; WolfeIV, Edward; Craig, Timothy

Without the waste heat available from the engine of a conventional automobile, electric vehicles (EVs) must provide heat to the cabin for climate control using energy stored in the vehicle. In current EV designs, this energy is typically provided by the traction battery. In very cold climatic conditions, the power required to heat the EV cabin can be of a similar magnitude to that required for propulsion of the vehicle. As a result, the driving range of an EV can be reduced very significantly during winter months, which limits consumer acceptance of EVs and results in increased battery costs tomore » achieve a minimum range while ensuring comfort to the EV driver. To minimize the range penalty associated with EV cabin heating, a novel climate control system that includes thermal energy storage has been designed for use in EVs and plug-in hybrid electric vehicles (PHEVs). The system uses the stored latent heat of an advanced phase change material (PCM) to provide cabin heating. The PCM is melted while the EV is connected to the electric grid for charging of the electric battery, and the stored energy is subsequently transferred to the cabin during driving. To minimize thermal losses when the EV is parked for extended periods, the PCM is encased in a high performance insulation system. The electrical PCM-Assisted Thermal Heating System (ePATHS) was designed to provide enough thermal energy to heat the EV s cabin for approximately 46 minutes, covering the entire daily commute of a typical driver in the U.S.« less

Multiple layer insulation cover

DOEpatents

Farrell, James J.; Donohoe, Anthony J.

1981-11-03

A multiple layer insulation cover for preventing heat loss in, for example, a greenhouse, is disclosed. The cover is comprised of spaced layers of thin foil covered fabric separated from each other by air spaces. The spacing is accomplished by the inflation of spaced air bladders which are integrally formed in the cover and to which the layers of the cover are secured. The bladders are inflated after the cover has been deployed in its intended use to separate the layers of the foil material. The sizes of the material layers are selected to compensate for sagging across the width of the cover so that the desired spacing is uniformly maintained when the cover has been deployed. The bladders are deflated as the cover is stored thereby expediting the storage process and reducing the amount of storage space required.

Application of High-Resolution Thermal Infrared Remote Sensing and GIS to Assess the Urban Heat Island Effect

NASA Technical Reports Server (NTRS)

Lo, C. P.; Quattrochi, D. A.; Luvall, J. C.

1997-01-01

Day and night airborne thermal infrared image data at 5 m spatial resolution acquired with the 15-channel (0.45 micron - 12.2 micron) Advanced Thermal and Land Applications Sensor (ATLAS) over Alabama, Huntsville on 7 September, 1994 were used to study changes in the thermal signatures of urban land cover types between day and night. Thermal channel number 13 (9.6 micron - 10.2 micron) data with the best noise-equivalent temperature change (NEAT) of 0.25 C after atmospheric corrections and temperature calibration were selected for use in this analysis. This research also examined the relation between land cover irradiance and vegetation amount, using the Normalized Difference Vegetation Index (NDVI), obtained by ratioing the difference and the sum of the red (channel number 3: 0.60-0.63 micron) and reflected infrared (channel number 6: 0.76-0.90 micron) ATLAS data. Based on the mean radiance values, standard deviations, and NDVI extracted from 351 pairs of polygons of day and night channel number 13 images for the city of Huntsville, a spatial model of warming and cooling characteristics of commercial, residential, agricultural, vegetation, and water features was developed using a GIS approach. There is a strong negative correlation between NDVI and irradiance of residential, agricultural, and vacant/transitional land cover types, indicating that the irradiance of a land cover type is greatly influenced by the amount of vegetation present. The predominance of forests, agricultural, and residential uses associated with varying degrees of tree cover showed great contrasts with commercial and services land cover types in the center of the city, and favors the development of urban heat islands. The high-resolution thermal infrared images match the complexity of the urban environment, and are capable of characterizing accurately the urban land cover types for the spatial modeling of the urban heat island effect using a GIS approach.

Glove and mitten protection in extreme cold weather: an Antarctic study.

PubMed

Iserson, Kenneth V

2016-01-01

Background Myths, misconceptions and a general lack of information surround the use of gloves and mittens in extreme cold environments. Objective This study assessed how well an assortment of gloves and mittens performed in a very cold environment. Methods A convenience sample of gloves and mittens were tested in Antarctica during the winter of 2016 using a calibrated thermometer (range: -148°F to +158°F/-100°C to +70°C) three times over a 0.5-mile distance (~20 minutes). A small sensor on a 10-foot-long cable was taped to the radial surface of the distal small finger on the non-dominant hand. The tested clothing was donned over the probe, the maximum temperature inside the glove/mitten was established near a building exit (ambient temperature approximately 54°F/12°C), and the building was exited, initiating the test. The hand was kept immobile during the test. Some non-heated gloves were tested with chemical heat warmers placed over the volar or dorsal wrist. Results The highest starting (96°F/36°C) and ending (82°F/28°C) temperatures were with electrically heated gloves. The lowest starting temperature was with electrically heated gloves with the power off (63°F/17°C). Non-heated gloves with an inserted chemical hand warmer had the lowest minimum temperature (33°F/1°C). Maximum temperatures for gloves/mittens did not correlate well with their minimum temperature. Conclusions Coverings that maintained finger temperatures within a comfortable and safe range (at or above 59°F/15°C) included the heated gloves and mittens (including some with the power off) and mittens with liners. Mittens without liners (shell) generally performed better than unheated gloves. Better results generally paralleled the item's cost. Inserting chemical heat warmers at the wrist increased heat loss, possibly through the exposed area around the warmer.

Glove and mitten protection in extreme cold weather: an Antarctic study.

PubMed

Iserson, Kenneth V

2016-01-01

Myths, misconceptions and a general lack of information surround the use of gloves and mittens in extreme cold environments. This study assessed how well an assortment of gloves and mittens performed in a very cold environment. A convenience sample of gloves and mittens were tested in Antarctica during the winter of 2016 using a calibrated thermometer (range: -148°F to +158°F/-100°C to +70°C) three times over a 0.5-mile distance (~20 minutes). A small sensor on a 10-foot-long cable was taped to the radial surface of the distal small finger on the non-dominant hand. The tested clothing was donned over the probe, the maximum temperature inside the glove/mitten was established near a building exit (ambient temperature approximately 54°F/12°C), and the building was exited, initiating the test. The hand was kept immobile during the test. Some non-heated gloves were tested with chemical heat warmers placed over the volar or dorsal wrist. The highest starting (96°F/36°C) and ending (82°F/28°C) temperatures were with electrically heated gloves. The lowest starting temperature was with electrically heated gloves with the power off (63°F/17°C). Non-heated gloves with an inserted chemical hand warmer had the lowest minimum temperature (33°F/1°C). Maximum temperatures for gloves/mittens did not correlate well with their minimum temperature. Coverings that maintained finger temperatures within a comfortable and safe range (at or above 59°F/15°C) included the heated gloves and mittens (including some with the power off) and mittens with liners. Mittens without liners (shell) generally performed better than unheated gloves. Better results generally paralleled the item's cost. Inserting chemical heat warmers at the wrist increased heat loss, possibly through the exposed area around the warmer.

Saving Energy. Managing School Facilities, Guide 3.

ERIC Educational Resources Information Center

Department for Education and Employment, London (England). Architects and Building Branch.

This guide offers information on how schools can implement an energy saving action plan to reduce their energy costs. Various low-cost energy-saving measures are recommended covering heating levels and heating systems, electricity demand reduction and lighting, ventilation, hot water usage, and swimming pool energy management. Additional…

Heat resistant protective hand covering

NASA Technical Reports Server (NTRS)

Tschirch, R. P.; Sidman, K. R.; Arons, I. J. (Inventor)

1984-01-01

A heat-resistant aromatic polyamide fiber is described. The outer surface of the shell is coated with a fire-resistant elastomer and liner. Generally conforming and secured to the shell and disposed inwardly of the shell, the liner is made of a felt fabric of temperature-resistant aromatic polymide fiber.

School Designed To Use 80 Percent Less Energy

ERIC Educational Resources Information Center

American School and University, 1975

1975-01-01

The new Terraset Elementary School in Reston, Virginia, uses earth as a cover for the roof area and for about 80 percent of the wall area. A heat recovery system will be used with solar collectors playing a primary role in heating and cooling. (Author/MLF)

Machinist's Mate 1 and C: Rate Training Manual.

ERIC Educational Resources Information Center

Naval Training Command, Pensacola, FL.

The rate training manual covers the duties required to efficiently operate and maintain ship propulsion machinery and associated equipment and to maintain applicable records and reports. Chapters cover: turbines; reduction gears; steam-driven generators; heat exchangers and air ejectors; pumps; piping and valves; distilling plants; refrigeration…

THERMAL-INERTIA MAPPING IN VEGETATED TERRAIN FROM HEAT CAPACITY MAPPING MISSION SATELLITE DATA.

USGS Publications Warehouse

Watson, Ken; Hummer-Miller, Susanne

1984-01-01

Thermal-inertia data, derived from the Heat Capacity Mapping Mission (HCMM) satellite, were analyzed in areas of varying amounts of vegetation cover. Thermal differences which appear to correlate with lithologic differences have been observed previously in areas of substantial vegetation cover. However, the energy exchange occurring within the canopy is much more complex than that used to develop the methods employed to produce thermal-inertia images. Because adequate models are lacking at present, the interpretation is largely dependent on comparison, correlation, and inference. Two study areas were selected in the western United States: the Richfield, Utah and the Silver City, Arizona-New Mexico, 1 degree multiplied by 2 degree quadrangles. Many thermal-inertia highs were found to be associated with geologic-unit boundaries, faults, and ridges. Lows occur in valleys with residual soil cover.

Minimum mass design of large-scale space trusses subjected to thermal gradients

NASA Technical Reports Server (NTRS)

Williams, R. Brett; Agnes, Gregory S.

2006-01-01

Lightweight, deployable trusses are commonly used to support space-borne instruments including RF reflectors, radar panels, and telescope optics. While in orbit, these support structures are subjected to thermal gradients that vary with altitude, location in orbit, and self-shadowing. Since these instruments have tight dimensional-stability requirements, their truss members are often covered with multi-layer insulation (MLI) blankets to minimize thermal distortions. This paper develops a radiation heat transfer model to predict the thermal gradient experienced by a triangular truss supporting a long, linear radar panel in Medium Earth Orbit (MEO). The influence of self-shadowing effects of the radar panel are included in the analysis, and the influence of both MLI thickness and outer covers/coatings on the magnitude of the thermal gradient are formed into a simple, two-dimensional analysis. This thermal model is then used to size and estimate the structural mass of a triangular truss that meets a given set of structural requirements.

[Study on composing prescription laws of treating aplastic anemia by Chinese medicine using applying data mining technique].

PubMed

Xiang, Yang; Yu, Jing-Wei; Cheng, Yu-Bin; Li, Hai-Xi; Chang, Xiao-Hui; Zhou, Da-Wei; Sun, Feng; Fang, Yong-Guang

2013-07-01

To explore composing prescription laws of treating aplastic anemia (AA) by Chinese medicine (CM). The literatures on treating AA by CM were recruited from various medical periodicals at home from 1979 to 2009 including China National Knowledge Infrastructure (CNKI), VIP information network, and Wangfang data knowledge service platform. The database correlated to CM features was established using the technique of computer data bank. The data mining (DM) technique was applied to analyze drugs sorts, frequency of drug application, and association degree. Three hundred and eleven pertinent literatures including 677 prescriptions and 254 Chinese herbs (CHs) were screened. There were 69 CHs for invigorating deficiency, 42 for heat clearing, 20 for promoting blood circulation and removing blood stasis, 16 for arresting bleeding, and 16 for relieving exterior syndrome, which occupied the top 5. The frequency of drug application of 254 CHs amounted to 7 547, in which the frequency of drug application of Mongolian milkvetch root, Rehmannia root, Suberect spatholobus stem, Hairyvein agrimonia herb, and Chinese thorowax root were 379, 248, 167, 85, and 13 respectively, and they occupied the first place of CHs for invigorating deficiency, heat clearing, promoting blood circulation and removing blood stasis, arresting bleeding, and relieving exterior syndrome, respectively. The number of the prescriptions containing 12, 10, and 11 CHs was occupied the top 3. The coverage rate of the prescription including Mongolian milkvetch root and Chinese angelica was 60%, and thus 4 core drugs groups were established covering invigorating qi and enriching the blood, reinforcing Shen and supporting yang, replenishing yin to tonify Shen, tonifying Shen to replenish essence, and invigorating qi and enriching blood respectively. Summarized were six potential composing prescription laws covering invigorating qi and enriching blood, reinforcing Shen and supporting yang, replenishing yin to tonify Shen, strengthening Pi and harmonizing Wei, tonifying the blood and promoting blood circulation, clearing away heat and toxic materials, and removing heat from the blood to stop bleeding. Applying DM technique, the fundamental core drugs groups consisting of Mongolian milkvetch root and Chinese angelica were discovered. The 4 core drugs groups established were in accordance with the realization of modern CM for the pathomechanism of AA. The 6 composing prescription laws summarized revealed the rules of drug application.

Adverse Impact of Electromagnetic Radiation on Urban Environment and Natural Resources using Optical Sensors

NASA Astrophysics Data System (ADS)

Kumar, Pawan; Katiyar, Swati; Rani, Meenu

2016-07-01

We are living in the age of a rapidly growing population and changing environmental conditions with an advance technical capacity.This has resulted in wide spread land cover change. One of the main causes for increasing urban heat is that more than half of the world's population lives in a rapidly growing urbanized environment. Satellite data can be highly useful to map change in land cover and other environmental phenomena with the passage of time. Among several human-induced environmental and urban thermal problems are reported to be negatively affecting urban residents in many ways. The built-up structures in urbanized areas considerably alter land cover thereby affecting thermal energy flow which leads to development of elevated surface and air temperature. The phenomenon Urban Heat Island implies 'island' of high temperature in cities, surrounded by relatively lower temperature in rural areas. The UHI for the temporal period is estimated using geospatial techniques which are then utilized for the impact assessment on climate of the surrounding regions and how it reduce the sustainability of the natural resources like air, vegetation. The present paper describes the methodology and resolution dynamic urban heat island change on climate using the geospatial approach. NDVI were generated using day time LANDSAT ETM+ image of 1990, 2000 and 2013. Temperature of various land use and land cover categories was estimated. Keywords: NDVI, Surface temperature, Dynamic changes.

Why wrapping premature neonates to prevent hypothermia can predispose to overheating.

PubMed

Agourram, Bouchra; Bach, Véronique; Tourneux, Pierre; Krim, Gérard; Delanaud, Stéphane; Libert, Jean-Pierre

2010-06-01

Wrapping low-birth-weight neonates in a plastic bag prevents body heat loss. A bonnet can also be used, since large amounts of heat can be lost from the head region, but may provide too much thermal insulation, thus increasing the risk of overheating. We assessed the time required to reach warning body temperature (t38 degrees C), heat stroke (t40 degrees C), or extreme value (t43 degrees C) in a mathematical model that involved calculating various local body heat losses. Simulated heat exchanges were based on body surface temperature distribution measured in preterm neonates exposed to 33 degrees C air temperature (relative air humidity: 35%; air velocity: <0.1 m/s) and covered (torso and limbs) or not with a transparent plastic bag. We also compared metabolic heat production with body heat losses when a bonnet (2 or 3.5 mm thick) covered 10%, 40%, or 100% of the head. Wrapping neonates in a bag (combined or not with a bonnet) does not induce a critical situation as long as metabolic heat production does not increase. When endogenous heat production rises, t38 degrees C ranged between 75 and 287, t40 degrees C between 185 and 549, and t43 degrees C between 287 and 702 min. When this increase was accompanied by a fall in skin temperature, overheating risk was accentuated (37

Planform structure and heat transfer in turbulent free convection over horizontal surfaces

NASA Astrophysics Data System (ADS)

Theerthan, S. Ananda; Arakeri, Jaywant H.

2000-04-01

This paper deals with turbulent free convection in a horizontal fluid layer above a heated surface. Experiments have been carried out on a heated surface to obtain and analyze the planform structure and the heat transfer under different conditions. Water is the working fluid and the range of flux Rayleigh numbers (Ra) covered is 3×107-2×1010. The different conditions correspond to Rayleigh-Bénard convection, convection with either the top water surface open to atmosphere or covered with an insulating plate, and with an imposed external flow on the heated boundary. Without the external flow the planform is one of randomly oriented line plumes. At large Rayleigh number Ra and small aspect ratio (AR), these line plumes seem to align along the diagonal, presumably due to a large scale flow. The side views show inclined dyelines, again indicating a large scale flow. When the external flow is imposed, the line plumes clearly align in the direction of external flow. The nondimensional average plume spacing, Raλ1/3, varies between 40 and 90. The heat transfer rate, for all the experiments conducted, represented as RaδT-1/3, where δT is the conduction layer thickness, varies only between 0.1-0.2, showing that in turbulent convection the heat transfer rates are similar under the different conditions.

Thermodynamic data for biomass conversion and waste incineration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Domalski, E.S.; Jobe, T.L. Jr; Milne, T.A.

1986-09-01

The general purpose of this collection of thermodynamic data of selected materials is to make property information available to the engineering community on chemical mixtures, polymers, composite materials, solid wastes, biomass, and materials not easily identifiable by a single stoichiometric formula. More than 700 materials have been compiled covering properties such as specific heat, gross heat of combustion, heat of fusion, heat of vaporization, and vapor pressure. The information was obtained from the master files of the NBS Chemical Thermodynamics Data Center, the annual issues of the Bulletin of Chemical Thermodynamics, intermittent examinations of the Chemical Abstracts subject indexes, individualmore » articles by various authors, and other general reference sources. The compilation is organized into several broad categories; materials are listed alphabetically within each category. For each material, the physical state, information as to the composition or character of the material, the kind of thermodynamic property reported, the specific property values for the material, and citations to the reference list are given. In addition, appendix A gives an empirical formula that allows heats of combustion of carbonaceous materials to be predicted with surprising accuracy when the elemental composition is known. A spread sheet illustrates this predictability with examples from this report and elsewhere. Appendix B lists some reports containing heats of combustion not included in this publication. Appendix C contains symbols, units, conversion factors, and atomic weights used in evaluating and compiling the thermodynamic data.« less

Solar/Geothermal Saves Energy in Heating and Cooling of Greenhouses

NASA Astrophysics Data System (ADS)

Sanders, Matthew; Thompson, Mark; Sikorski, Yuri

2010-04-01

The steady increase in world population and problems associated with conventional agricultural practices demand changes in food production methods and capabilities. Locally grown food minimizes the transportation costs and gas emissions responsible for Global Warming. Greenhouses have the potential to be extremely ecologically friendly by greatly increasing yields per year and facilitating reduced pesticide use. Globally, there are 2.5 million acres of greenhouse cover, including 30,640 acres in North America. In Europe, greenhouses consume 10% of the total energy in agriculture. Most of that energy is utilized for heating. Heating and cooling amount to 35% of greenhouse production costs. This high percentage value can be partially attributed to currently poor insulation values. In moderate-to-cold climate zones, it can take up to 2,500 gallons of propane, currently costing around 5,000, to keep a 2,000 sq. ft. greenhouse producing all winter. Around 350 tons of CO2 per acre per year are released from these structures, contributing to global climate change. Reducing the energy needs of a greenhouse is the first step in saving money and the environment. Therefore, an efficient and environmentally friendly heating and cooling system selection is also crucial. After selecting appropriate energy sources, the next major concern in a greenhouse would be heat loss. Consequently, it is critically important to understand factors contributing to heat loss.

Structural Mineral Physics at Extreme Conditions

NASA Astrophysics Data System (ADS)

Chariton, S.; Dubrovinsky, L. S.; Dubrovinskaia, N.

2017-12-01

Laser heating techniques in diamond anvil cells (DACs) cover a wide pressure-temperature range - above 300 GPa and up to 5000 K. Recent advantages in on-line laser heating techniques resulted in a significant improvement of reliability of in situ X-ray powder diffraction studies in laser-heated DACs, which have become routine at a number of synchrotron facilities including specialized beam-lines at the 3rd generation synchrotrons. However, until recently, existing DAC laser-heating systems could not be used for structural X-ray diffraction studies aimed at structural refinements, i.e. measuring of the diffraction intensities, and not only at determining of lattice parameters. The reason is that in existing DAC laser-heating facilities the laser beam enters the cell at a fixed angle, and a partial rotation of the DAC, as required in monochromatic structural X-ray diffraction experiments, results in a loss of the target crystal and may be even dangerous if the powerful laser light starts to scatter in arbitrary directions by the diamond anvils. In order to overcome this problem we have develop a portable laser heating system and implement it at different diffraction beam lines. We demonstrate the application of this system for simultaneous high-pressure and high-temperature powder and single crystal diffraction studies using examples of studies of chemical and phase relations in the Fe-O system, transition metals carbonates, and silicate perovskites.

A Changing Arctic Sea Ice Cover and the Partitioning of Solar Radiation

NASA Astrophysics Data System (ADS)

Perovich, D. K.; Light, B.; Polashenski, C.; Nghiem, S. V.

2010-12-01

Certain recent changes in the Arctic sea ice cover are well established. There has been a reduction in sea ice extent, an overall thinning of the ice cover, reduced prevalence of perennial ice with accompanying increases in seasonal ice, and a lengthening of the summer melt season. Here we explore the effects of these changes on the partitioning of solar energy between reflection to the atmosphere, absorption within the ice, and transmission to the ocean. The physical changes in the ice cover result in less light reflected and more light absorbed in the ice and transmitted to the ocean. These changes directly affect the heat and mass balance of the ice as well as the amount of light available for photosynthesis within and beneath the ice cover. The central driver is that seasonal ice covers tend to have lower albedo than perennial ice throughout the melt season, permitting more light to penetrate into the ice and ocean. The enhanced light penetration increases the amount of internal melting of the ice and the heat content of the upper ocean. The physical changes in the ice cover mentioned above have affected both the amount and the timing of the photosynthetically active radiation (PAR) transmitted into the ice and ocean, increasing transmitted PAR, particularly in the spring. A comparison of the partitioning of solar irradiance and PAR for both historical and recent ice conditions will be presented.

Use of a turboexpander in steam power units for heat energy recovery in heat supply systems

NASA Astrophysics Data System (ADS)

Sadykov, R. A.; Daminov, A. Z.; Solomin, I. N.; Futin, V. A.

2016-05-01

A method for raising the efficiency of a boiler plant by installing a unit operating by the organic Rankine cycle is presented. Such units allow one to generate electricity to cover the auxiliaries of a heat source at a heat-transfer fluid temperature of no more than 130°C. The results of commissioning tests of boilers revealed that their efficiency is maximized under a load that is close or corresponds to the nominal one. If this load is maintained constantly, excess heat energy is produced. This excess may be used to generate electric energy in a steam power unit with a turboexpander. A way to insert this unit into the flow diagram of a boiler plant is proposed. The results of analysis of turbine types (turboexpanders included) with various capacities are presented, and the optimum type for the proposed flow diagram is chosen. The methodology for the design of turboexpanders and compressors used in the oil and gas industry and their operational data were applied in the analysis of a turboexpander. The results of the thermogasdynamic analysis of a turboexpander and the engineered shape of an axial-radial impeller are presented. Halocarbon R245fa is chosen as the working medium based on its calorimetric properties.

Projected changes in atmospheric heating due to changes in fire disturbance and the snow season in the western Arctic, 2003-2100

Treesearch

E.S. Euskirchen; A.D. McGuire; T.S. Rupp; F.S. Chapin; J.E. Walsh

2009-01-01

In high latitudes, changes in climate impact fire regimes and snow cover duration, altering the surface albedo and the heating of the regional atmosphere. In the western Arctic, under four scenarios of future climate change and future fire regimes (2003-2100), we examined changes in surface albedo and the related changes in regional atmospheric heating due to: (1)...

Sunlight, Sea Ice, and the Ice Albedo Feedback in a Changing Arctic Sea Ice Cover

DTIC Science & Technology

2013-09-30

Sea Ice , and the Ice Albedo Feedback in a...COVERED 00-00-2013 to 00-00-2013 4. TITLE AND SUBTITLE Sunlight, Sea Ice , and the Ice Albedo Feedback in a Changing Arctic Sea Ice Cover 5a...during a period when incident solar irradiance is large increasing solar heat input to the ice . Seasonal sea ice typically has a smaller albedo

Nondestructive corrosion detection in concrete through integrated heat induction and IR thermography

NASA Astrophysics Data System (ADS)

Kwon, Seung-Jun; Xue, Henry; Feng, Maria Q.; Baek, Seunghoon

2011-04-01

Steel corrosion in concrete is a main cause of deterioration and early failure of concrete structures. A novel integration of electromagnetic heat induction and infrared (IR) thermography is proposed for nondestructive detection of steel corrosion in concrete, by taking advantage of the difference in thermal characteristics of corroded and non-corroded steel. This paper focuses on experimental investigation of the concept. An inductive heater is developed to remotely heat the steel rebar from concrete surface, which is integrated with an IR camera. Bare rebar and concrete samples with different cover depths are prepared. Each concrete sample is embedded with a single steel rebar in the middle, resulting an identical cover depth from the front and the back surfaces, which enables heat induction from one surface and IR thermogrphay from the other simultaneously. The impressed current method is adopted to induce accelerated corrosion on the rebar. IR video images are recorded during both heating and cooling periods. The test results demonstrate a clear difference in thermal characteristics between corroded and non-corroded samples. The corroded samples show higher rates of heating and cooling as well as a higher peak IR intensity than those of the non-corroded samples. This study demonstrates a potential for nondestructive detection of rebar corrosion in concrete.

Effects of soil water and heat relationship under various snow cover during freezing-thawing periods in Songnen Plain, China.

PubMed

Fu, Qiang; Hou, Renjie; Li, Tianxiao; Jiang, Ruiqi; Yan, Peiru; Ma, Ziao; Zhou, Zhaoqiang

2018-01-22

In this study, the spatial variations of soil water and heat under bare land (BL), natural snow (NS), compacted snow (CS) and thick snow (TS) treatments were analyzed. The relationship curve between soil temperature and water content conforms to the exponential filtering model, by means of the functional form of the model, it was defined as soil water and heat relation function model. On this basis, soil water and heat function models of 10, 20, 40, 60, 100, and 140 cm were established. Finally, a spatial variation law of the relationship effect was described based on analysising of the differences between the predicted and measured results. During freezing period, the effects of external factors on soil were hindered by snow cover. As the snow increased, the accuracy of the function model gradually improved. During melting period, infiltration by snowmelt affected the relationship between the soil temperature and moisture. With the increasing of snow, the accuracy of the function models gradually decreased. The relationship effects of soil water and heat increased with increasing depth within the frozen zone. In contrast, below the frozen layer, the relationship of soil water and heat was weaker, and the function models were less accurate.

Method and apparatus for implementing material thermal property measurement by flash thermal imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Jiangang

A method and apparatus are provided for implementing measurement of material thermal properties including measurement of thermal effusivity of a coating and/or film or a bulk material of uniform property. The test apparatus includes an infrared camera, a data acquisition and processing computer coupled to the infrared camera for acquiring and processing thermal image data, a flash lamp providing an input of heat onto the surface of a two-layer sample with an enhanced optical filter covering the flash lamp attenuating an entire infrared wavelength range with a series of thermal images is taken of the surface of the two-layer sample.

Turbulent Supersonic/Hypersonic Heating Correlations for Open and Closed Cavities

NASA Technical Reports Server (NTRS)

Everhart, Joel L.; Greene, Francis A.

2009-01-01

Supersonic/hypersonic laminar heating correlations that were developed for damage assessment analysis of atmospheric re-entry vehicles have been modified and extended to cover fully-turbulent conditions over rectangular cavity geometries that are aligned with the local velocity. Turbulent boundary layer properties were computationally determined and used to develop the cavity geometry parametrics and to correlate experimental closed cavity heating data to yield new relationships for the floor-averaged and centerline endwall peak-heating augmentation. With the form of the closed-cavity correlations established, historical data were used to develop new correlations for turbulent open-cavity heating.

40 CFR 264.1031 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... with or without the application of heat to the liquid. Packed towers, spray towers, and bubble-cap.... Condenser means a heat-transfer device that reduces a thermodynamic fluid from its vapor phase to its liquid... means flanged fittings that are not covered by insulation or other materials that prevent location of...

40 CFR 264.1031 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... with or without the application of heat to the liquid. Packed towers, spray towers, and bubble-cap.... Condenser means a heat-transfer device that reduces a thermodynamic fluid from its vapor phase to its liquid... means flanged fittings that are not covered by insulation or other materials that prevent location of...

40 CFR 264.1031 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... with or without the application of heat to the liquid. Packed towers, spray towers, and bubble-cap.... Condenser means a heat-transfer device that reduces a thermodynamic fluid from its vapor phase to its liquid... means flanged fittings that are not covered by insulation or other materials that prevent location of...

40 CFR 264.1031 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... with or without the application of heat to the liquid. Packed towers, spray towers, and bubble-cap.... Condenser means a heat-transfer device that reduces a thermodynamic fluid from its vapor phase to its liquid... means flanged fittings that are not covered by insulation or other materials that prevent location of...

Insulator (Heat and Frost). Occupational Analyses Series.

ERIC Educational Resources Information Center

McRory, Aline; Ally, Mohamed

This analysis covers tasks performed by an insulator, an occupational title some provinces and territories of Canada have also identified as heat and frost insulator. A guide to analysis discusses development, structure, and validation method; scope of the occupation; trends; and safety. To facilitate understanding the nature of the occupation,…

How to Save Money by Saving Energy.

ERIC Educational Resources Information Center

Department of Energy, Washington, DC.

This pamphlet presents energy conservation tips to help consumers save money. Conservation measures suggested here cover topics such as: (1) insulation; (2) space heating and cooling; (3) hot water heating; (4) cooking; (5) laundry; (6) lighting; (7) electrical appliances; (8) buying or building a home; and (9) buying, maintaining and driving a…

40 CFR 264.1031 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... with or without the application of heat to the liquid. Packed towers, spray towers, and bubble-cap.... Condenser means a heat-transfer device that reduces a thermodynamic fluid from its vapor phase to its liquid... means flanged fittings that are not covered by insulation or other materials that prevent location of...

Solar heated beehives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hardin, B.

1985-02-01

A new translucent plastic cover for bee hives is described which will serve as a passive solar collector and insulator. Scientists at the USDA-ARS designed the cover to maintain bees in cold weather. It should be of interest to beekeepers in northern states who have had to destroy colonies to avoid overwintering costs.

The dry-heat loss effect of melt-spun phase change material fibres.

PubMed

Tjønnås, Maria Suong; Færevik, Hilde; Sandsund, Mariann; Reinertsen, Randi E

2015-01-01

Phase change materials (PCM) have the ability to store latent heat when they change phases, a property that gives clothing that incorporates PCM its cooling effect. This study investigated the effect of dry-heat loss (cooling) of a novel melt-spun PCM fibre on the basis of the area covered, mass, the latent heat of fusion and melting temperature, compared to a known PCM clothing product. PCM fibres with melting temperatures of 28.4 and 32.0°C and PCM packs with melting temperatures of 28.0 and 32.0°C were studied. The results showed that the PCM fibres had a larger initial peak cooling effect than that of the PCM packs. The duration of the cooling effect of PCM fibres was primarily dependent on the PCM mass and the latent heat of fusion capacity, and secondly on the covered area and melting temperature of the PCM. This study investigates the cooling effect of PCM fibres on a thermal manikin. The PCM fibres had a high but short-lasting cooling effect. This study contributes to the knowledge of how the body's temperature regulation may be affected by the cooling properties of clothing that incorporates PCM.

Droplet-surface Impingement Dynamics for Intelligent Spray Design

NASA Technical Reports Server (NTRS)

VanderWal, Randy L.; Kizito, John P.; Tryggvason, Gretar; Berger, Gordon M.; Mozes, Steven D.

2004-01-01

Spray cooling has high potential in thermal management and life support systems by overcoming the deleterious effect of microgravity upon two-phase heat transfer. In particular spray cooling offers several advantages in heat flux removal that include the following: 1. By maintaining a wetted surface, spray droplets impinge upon a thin fluid film rather than a dry solid surface 2. Most heat transfer surfaces will not be smooth but rough. Roughness can enhance conductive cooling, aid liquid removal by flow channeling. 3. Spray momentum can be used to a) substitute for gravity delivering fluid to the surface, b) prevent local dryout and potential thermal runaway and c) facilitate liquid and vapor removal. Yet high momentum results in high We and Re numbers characterizing the individual spray droplets. Beyond an impingement threshold, droplets splash rather than spread. Heat flux declines and spray cooling efficiency can markedly decrease. Accordingly we are investigating droplet impingement upon a) dry solid surfaces, b) fluid films, c) rough surfaces and determining splashing thresholds and relationships for both dry surfaces and those covered by fluid films. We are presently developing engineering correlations delineating the boundary between splashing and non-splashing regions.

Two-phase gas-liquid flow characteristics inside a plate heat exchanger

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nilpueng, Kitti; Wongwises, Somchai

In the present study, the air-water two-phase flow characteristics including flow pattern and pressure drop inside a plate heat exchanger are experimentally investigated. A plate heat exchanger with single pass under the condition of counter flow is operated for the experiment. Three stainless steel commercial plates with a corrugated sinusoidal shape of unsymmetrical chevron angles of 55 and 10 are utilized for the pressure drop measurement. A transparent plate having the same configuration as the stainless steel plates is cast and used as a cover plate in order to observe the flow pattern inside the plate heat exchanger. The air-watermore » mixture flow which is used as a cold stream is tested in vertical downward and upward flow. The results from the present experiment show that the annular-liquid bridge flow pattern appeared in both upward and downward flows. However, the bubbly flow pattern and the slug flow pattern are only found in upward flow and downward flow, respectively. The variation of the water and air velocity has a significant effect on the two-phase pressure drop. Based on the present data, a two-phase multiplier correlation is proposed for practical application. (author)« less

Design and Operation of the RHIC 80-K Cooler

NASA Astrophysics Data System (ADS)

Nicoletti, A.; Reuter, A.; Sidi-Yekhlef, A.; Talty, P.; Quimby, E.

2004-06-01

A stand-alone cryogenic system designed to maintain the magnets of the Relativistic Heavy Ion Collider (RHIC) at between 80 and 100 K during accelerator shutdown periods has been conceived and designed at Brookhaven National Laboratory and built by PHPK Technologies of Columbus, Ohio. Since most thermal contraction occurs above this temperature, this unit, referred to as the 80-K Cooler, will eliminate the stresses associated with thermal cycling. The cooling system will provide the necessary refrigeration by circulating cooled helium gas at approximately 1500 kPA through the RHIC heat shields and magnets. This helium is cooled by heat exchange with liquid nitrogen and circulated via three cold centrifugal pumps. The nominal delivered cooling capacity required to maintain the magnets at temperature is approximately 36 kW, primarily intercepted at the heat shield. The system also has separate heat exchangers for use as a pre-cooler from room temperature to 82 K. Selection of sextant or sextants for pre-cooling is designed into the RHIC cryogenic distribution system. Topics covered include Cooler design decisions, details of the Cooler as built, integration into the existing RHIC cryogenic system and initial operating experience.

Behavior of a tapered hub flange with a bolted flat cover in transient temperature field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sawa, T.; Nakagomi, Y.; Hirose, T.

1996-02-01

When bolted flange connections with gaskets are used in mechanical structures such as pipe connections, bolted covers of casks, and pressure vessels in nuclear and chemical plants and cylinder heads in internal combustion engines, they are usually subjected to transient thermal conditions. An experimental and analytical study was made on a bolted connection subjected to thermal loading. The connection consists of an aluminum alloy tapered hub flange and a flat cover, including a gasket fastened by steel bolts and nuts. Temperature distribution in the connection was measured with thermocouples, and the axial bolt force, the maximum bolt stress, and themore » hub stress were measured by strain gages under a thermal condition that the inner surface of the flanges was heated and the outer surfaces of the flanges and the cover were held at room temperature. Finite difference analysis was made to obtain the temperature distributions in the connection due to a transient thermal condition. This paper demonstrates the method for obtaining an increment in axial bolt force and the maximum bolt stress. In all cases, the analytical results were fairly consistent with the experimental results.« less

Radiative Forcing by Contrails

NASA Technical Reports Server (NTRS)

Meerkoetter, R.; Schumann, U.; Doelling, D. R.; Nakajima, T.; Tsushima, Y.

1999-01-01

A parametric study of the instantaneous radiative impact of contrails is presented using three different radiative transfer models for a series of model atmospheres and cloud parameters. Contrails are treated as geometrically and optically thin plane parallel homogeneous cirrus layers in a static atmospheres The ice water content is varied as a function of ambient temperature. The model atmospheres include tropical, mid-latitude, and subarctic summer and winter atmospheres Optically thin contrails cause a positive net forcing at top of the atmosphere. At the surface the radiative forcing is negative during daytime. The forcing increases with the optical depth and the amount of contrail cover. At the top of the atmosphere a mean contrail cover of 0.1% with average optical depth of 0.2 to 0.5 causes about 0.01 to 0.03 W/m(exp 2)a daily mean instantaneous radiative forcing. Contrails cool the surface during the day and heat the surface during the night, and hence reduce the daily temperature amplitude The net effect depends strongly on the daily variation of contrail cloud cover. The indirect radiative forcing due to particle changes in natural cirrus clouds may be of the same magnitude as the direct one due to additional cover.

Thermal characteristics of the 12-gigahertz, 200-watt output stage tube for the communications technology satellite

NASA Technical Reports Server (NTRS)

Curren, A. N.

1978-01-01

A description of the methods used to measure component temperatures and heat-rejection rates in a simulated space environment on output stage tubes (OST's) developed for the Communications Technology Satellite is presented along with summaries of experimentally determined values. The OST's were operated over the entire anticipated operating drive range, from the dc beam (zero drive) condition to the 6-db overdrive condition. The baseplate temperature was varied from -10 to 58 C with emphasis placed on the testing done at 45 C, the normal anticipated operating temperature. The heat-rejection rate of the OST baseplate ranged from 7.6 W at the dc beam condition to 184.5 W at the 6-db overdrive condition; the heat-rejection rate of the multistage depressed collector (MDC) cover ranged from 192.2 to 155.9 W for the same conditions. The maximum OST temperature measured on the MDC cover was 227 C during a dc beam test. The minimum temperature measured, also on the MDC cover, was -67.5 C at the end of an extended simulated eclipse test period. No effects were observed on the OST thermal characteristics due to vibration testing or temperature-reversal cycle testing.

High Temperature Latent Heat Thermal Energy Storage to Augment Solar Thermal Propulsion for Microsatellites

DTIC Science & Technology

2014-03-01

Charts 3. DATES COVERED (From - To) Mar 2014- May 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER In-House High Temperature Latent Heat Thermal ...Energy Storage to Augment Solar Thermal Propulsion for Microsats 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER...High Temperature Latent Heat Thermal Energy Storage to Augment Solar Thermal Propulsion for Microsatellites Presentation Subtitle Matthew R. Gilpin

Heat resistant protective hand covering

NASA Technical Reports Server (NTRS)

Sidman, K. R.; Arons, I. J. (Inventor)

1984-01-01

The heat resistant, protective glove is made up of first and second shell sections which define a palm side and a backside, respectively. The first shell section is made of a twill wave fabric of a temperature-resistant aromatic polyamide fiber. The second shell section is made of a knitted fabric of a temperature-resistant aromatic polyamide fiber. The first and second shell sections are secured to one another, e.g., by sewing, to provide the desired glove configuration and an opening for insertion of the wearer's hand. The protective glove also includes a first liner section which is secured to and overlies the inner surface of the first shell section and is made of a felt fabric of a temperature-resistant aromatic polyamide fiber and has a flame resistant, elastomenic coating on the surface facing and overlying the inner surface of the first shell section.

A review and analysis of boundary layer transition data for turbine application

NASA Technical Reports Server (NTRS)

Gaugler, R. E.

1984-01-01

A symposium on transition in turbines was held at the NASA Lewis Research Center. One recommendation of the working groups was the collection of existing transition data to provide standard cases against which models could be tested. A number of data sets from the open literature that include heat transfer data in apparently transitional boundary layers, with particular application to the turbine environment, were reviewed and analyzed to extract transition information from the heat transfer data. The data sets reviewed cover a wide range of flow conditions, from low speed, flat plate tests to full scale turbine airfoils operating at simulated turbine engine conditions. The results indicate that free stream turbulence and pressure gradient have strong, and opposite, effects on the location of the start of transition and on the length of the transition zone.

A review and analysis of boundary layer transition data for turbine application

NASA Technical Reports Server (NTRS)

Gaugler, R. E.

1985-01-01

A symposium on transition in turbines was held at the NASA Lewis Research Center. One recommendation of the working groups was the collection of existing transition data to provide standard cases against which models could be tested. A number of data sets from the open literature that include heat transfer data in apparently transitional boundary layers, with particular application to the turbine environment, were reviewed and analyzed to extract transition information from the heat transfer data. The data sets reviewed cover a wide range of flow conditions, from low speed, flat plate tests to full scale turbine airfoils operating at simulated turbine engine conditions. The results indicate that free stream turbulence and pressure gradient have strong, and opposite, effects on the location of the start of transition and on the length of the transition zone.

Design, fabrication, testing and delivery of a solar collector

NASA Technical Reports Server (NTRS)

Sims, W. H.; Ballheim, R. W.; Bartley, S. M.; Smith, G. W.

1976-01-01

A two phase program encompassing the redesign and fabrication of a solar collector which is low in cost and aesthetically appealing is described. Phase one work reviewed the current collector design and developed a low-cost design based on specific design/performance/cost requirements. Throughout this phase selected collector component materials were evaluated by testing and by considering cost, installation, maintainability and durability. The resultant collector design was composed of an absorber plate, insulation, frame, cover, desiccant and sealant. In Phase two, three collector prototypes were fabricated and evaluated for both nonthermal and thermal characteristics. Tests included static load tests of covers, burst pressure tests of absorber plates, and tests for optical characteristics of selective absorber plate coatings. The three prototype collectors were shipped to Marshall Space Flight Center for use in their solar heating and cooling test facility.

Fuel change possibilities in small heat source

NASA Astrophysics Data System (ADS)

Durčanský, Peter; Kapjor, Andrej; Jandačka, Jozef

2017-09-01

Rural areas are characterized by a larger number of older family houses with higher fuel consumption for heating. Some areas are not gasified, which means that the fuel base for heating the buildings is very limited. Heating is mainly covered by solid fuels with high emissions and low efficiency. But at the same time, the amount of energy in the form of biowaste can be evaluated and used further. We will explore the possibilities to convert biogas to heat of using a gas burner in a small heat source. However, the heat produced can be used other than for heating or hot water production. The added value for heat generation can be the production of electricity, in the use of heat energy through cogeneration unit with unconventional heat engine. The proposed solution could economically benefit the entire system, because electricity is a noble form of energy and its use is versatile.

A review on boiling heat transfer enhancement with nanofluids

PubMed Central

2011-01-01

There has been increasing interest of late in nanofluid boiling and its use in heat transfer enhancement. This article covers recent advances in the last decade by researchers in both pool boiling and convective boiling applications, with nanofluids as the working fluid. The available data in the literature is reviewed in terms of enhancements, and degradations in the nucleate boiling heat transfer and critical heat flux. Conflicting data have been presented in the literature on the effect that nanofluids have on the boiling heat-transfer coefficient; however, almost all researchers have noted an enhancement in the critical heat flux during nanofluid boiling. Several researchers have observed nanoparticle deposition at the heater surface, which they have related back to the critical heat flux enhancement. PMID:21711794

Urban heat island-induced increases in evapotranspirative demand

NASA Astrophysics Data System (ADS)

Zipper, Samuel C.; Schatz, Jason; Kucharik, Christopher J.; Loheide, Steven P.

2017-01-01

Although the importance of vegetation in mitigating the urban heat island (UHI) is known, the impacts of UHI-induced changes in micrometeorological conditions on vegetation are not well understood. Here we show that plant water requirements are significantly higher in urban areas compared to rural areas surrounding Madison, WI, driven by increased air temperature with minimal effects of decreased air moisture content. Local increases in impervious cover are strongly associated with increased evapotranspirative demand in a consistent manner across years, with most increases caused by elevated temperatures during the growing season rather than changes in changes in growing season length. Potential evapotranspiration is up to 10% higher due to the UHI, potentially mitigating changes to the water and energy balances caused by urbanization. Our results indicate that local-scale land cover decisions (increases in impervious cover) can significantly impact evapotranspirative demand, with likely implications for water and carbon cycling in urban ecosystems.

Thermoelectric as recovery and harvesting of waste heat from portable generator

NASA Astrophysics Data System (ADS)

Mustafa, S. N.; Kamarrudin, N. S.; Hashim, M. S. M.; Bakar, S. A.; Razlan, Z. M.; Harun, A.; Ibrahim, I.; Faizi, M. K.; Saad, M. A. M.; Zunaidi, I.; Wan, W. K.; Desa, H.

2017-10-01

Generation of waste heat was ineluctable especially during energy producing process. Waste heat falls into low temperature grade make it complicated to utilize. Thermoelectric generator (TEG) offers opportunity to harvest any temperature grade heat into useful electricity. This project is covered about recovery and utilizing waste heat from portable electric generator by using a TEG which placed at exhaust surface. Temperature difference at both surfaces of TEG was enhanced with supplying cold air from a wind blower. It is found that, even at low air speed, the TEG was successfully produced electricity with aid from DC-DC booster. Results shows possibility to harvest low temperature grade heat and still exist areas for continual improvement.

Modeling of Thermal Performance of Multiphase Nuclear Fuel Cell Under Variable Gravity Conditions

NASA Technical Reports Server (NTRS)

Ding, Z.; Anghaie, S.

1996-01-01

A unique numerical method has been developed to model the dynamic processes of bulk evaporation and condensation processes, associated with internal heat generation and natural convection under different gravity levels. The internal energy formulation, for the bulk liquid-vapor phase change problems in an encapsulated container, was employed. The equations, governing the conservation of mass, momentum and energy for both phases involved in phase change, were solved. The thermal performance of a multiphase uranium tetra-fluoride fuel element under zero gravity, micro-gravity and normal gravity conditions has been investigated. The modeling yielded results including the evolution of the bulk liquid-vapor phase change process, the evolution of the liquid-vapor interface, the formation and development of the liquid film covering the side wall surface, the temperature distribution and the convection flow field in the fuel element. The strong dependence of the thermal performance of such multiphase nuclear fuel cell on the gravity condition has been revealed. Under all three gravity conditions, 0-g, 10(exp -3)-g, and 1-g, the liquid film is formed and covers the entire side wall. The liquid film covering the side wall is more isothermalized at the wall surface, which can prevent the side wall from being over-heated. As the gravity increases, the liquid film is thinner, the temperature gradient is larger across the liquid film and smaller across the vapor phase. This investigation provides valuable information about the thermal performance of multi-phase nuclear fuel element for the potential space and ground applications.

Thermal Investigation in the Cappadocia Region, Central Anatolia-Turkey, Analyzing Curie Point Depth, Geothermal Gradient, and Heat-Flow Maps from the Aeromagnetic Data

NASA Astrophysics Data System (ADS)

Bilim, Funda; Kosaroglu, Sinan; Aydemir, Attila; Buyuksarac, Aydin

2017-12-01

In this study, curie point depth (CPD), heat flow, geothermal gradient, and radiogenic heat production maps of the Cappadocian region in central Anatolia are presented to reveal the thermal structure from the aeromagnetic data. The large, circular pattern in these maps matches with previously determined shallow (2 km in average) depression. Estimated CPDs in this depression filled with loose volcano-clastics and ignimbrite sheets of continental Neogene units vary from 7 to 12 km, while the geothermal gradient increases from 50 to 68 °C/km. Heat flows were calculated using two different conductivity coefficients of 2.3 and 2.7 Wm-1 K-1. The radiogenic heat production was also obtained between 0.45 and 0.70 μW m-3 in this area. Heat-flow maps were compared with the previous, regional heat-flow map of Turkey and significant differences were observed. In contrast to linear heat-flow increment through the northeast in the previous map in the literature, produced maps in this study include a large, caldera-like circular depression between Nevsehir, Aksaray, Nigde, and Yesilhisar cities indicating high geothermal gradient and higher heat-flow values. In addition, active deformation is evident with young magmatism in the Neogene and Quaternary times and a large volcanic cover on the surface. Boundaries of volcanic eruption centers and buried large intrusions are surrounded with the maxspots of the horizontal gradients of magnetic anomalies. Analytic signal (AS) map pointing-out exact locations of causative bodies is also presented in this study. Circular region in the combined map of AS and maxspots apparently indicates a possible caldera.

Satellite-based detection of global urban heat-island temperature influence

USGS Publications Warehouse

Gallo, K.P.; Adegoke, Jimmy O.; Owen, T.W.; Elvidge, C.D.

2002-01-01

This study utilizes a satellite-based methodology to assess the urban heat-island influence during warm season months for over 4400 stations included in the Global Historical Climatology Network of climate stations. The methodology includes local and regional satellite retrievals of an indicator of the presence green photosynthetically active vegetation at and around the stations. The difference in local and regional samples of the normalized difference vegetation index (NDVI) is used to estimate differences in mean air temperature. Stations classified as urban averaged 0.90??C (N. Hemisphere) and 0.92??C (S. Hemisphere) warmer than the surrounding environment on the basis of the NDVI-derived temperature estimates. Additionally, stations classified as rural averaged 0.19??C (N. Hemisphere) and 0.16??C (S. Hemisphere) warmer than the surrounding environment. The NDVI-derived temperature estimates were found to be in reasonable agreement with temperature differences observed between climate stations. The results suggest that satellite-derived data sets can be used to estimate the urban heat-island temperature influence on a global basis and that a more detailed analysis of rural stations and their surrounding environment may be necessary to assure that temperature trends derived from assumed rural environments are not influenced by changes in land use/land cover. Copyright 2002 by the American Geophysical Union.

Characterization of post-fire surface cover, soils, and burn severity at the Cerro Grande Fire, New Mexico, using hyperspectral and multispectral remote sensing

USGS Publications Warehouse

Kokaly, R.F.; Rockwell, B.W.; Haire, S.L.; King, T.V.V.

2007-01-01

Forest fires leave behind a changed ecosystem with a patchwork of surface cover that includes ash, charred organic matter, soils and soil minerals, and dead, damaged, and living vegetation. The distributions of these materials affect post-fire processes of erosion, nutrient cycling, and vegetation regrowth. We analyzed high spatial resolution (2.4??m pixel size) Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) data collected over the Cerro Grande fire, to map post-fire surface cover into 10 classes, including ash, soil minerals, scorched conifer trees, and green vegetation. The Cerro Grande fire occurred near Los Alamos, New Mexico, in May 2000. The AVIRIS data were collected September 3, 2000. The surface cover map revealed complex patterns of ash, iron oxide minerals, and clay minerals in areas of complete combustion. Scorched conifer trees, which retained dry needles heated by the fire but not fully combusted by the flames, were found to cover much of the post-fire landscape. These scorched trees were found in narrow zones at the edges of completely burned areas. A surface cover map was also made using Landsat Enhanced Thematic Mapper plus (ETM+) data, collected September 5, 2000, and a maximum likelihood, supervised classification. When compared to AVIRIS, the Landsat classification grossly overestimated cover by dry conifer and ash classes and severely underestimated soil and green vegetation cover. In a comparison of AVIRIS surface cover to the Burned Area Emergency Rehabilitation (BAER) map of burn severity, the BAER high burn severity areas did not capture the variable patterns of post-fire surface cover by ash, soil, and scorched conifer trees seen in the AVIRIS map. The BAER map, derived from air photos, also did not capture the distribution of scorched trees that were observed in the AVIRIS map. Similarly, the moderate severity class of Landsat-derived burn severity maps generated from the differenced Normalized Burn Ratio (dNBR) calculation had low agreement with the AVIRIS classes of scorched conifer trees. Burn severity and surface cover images were found to contain complementary information, with the dNBR map presenting an image of degree of change caused by fire and the AVIRIS-derived map showing specific surface cover resulting from fire.

Assessing the relationship between surface urban heat islands and landscape patterns across climatic zones in China.

PubMed

Yang, Qiquan; Huang, Xin; Li, Jiayi

2017-08-24

The urban heat island (UHI) effect exerts a great influence on the Earth's environment and human health and has been the subject of considerable attention. Landscape patterns are among the most important factors relevant to surface UHIs (SUHIs); however, the relationship between SUHIs and landscape patterns is poorly understood over large areas. In this study, the surface UHI intensity (SUHII) is defined as the temperature difference between urban and suburban areas, and the landscape patterns are quantified by the urban-suburban differences in several typical landscape metrics (ΔLMs). Temperature and land-cover classification datasets based on satellite observations were applied to analyze the relationship between SUHII and ΔLMs in 332 cities/city agglomerations distributed in different climatic zones of China. The results indicate that SUHII and its correlations with ΔLMs are profoundly influenced by seasonal, diurnal, and climatic factors. The impacts of different land-cover types on SUHIs are different, and the landscape patterns of the built-up and vegetation (including forest, grassland, and cultivated land) classes have the most significant effects on SUHIs. The results of this study will help us to gain a deeper understanding of the relationship between the SUHI effect and landscape patterns.

Proceedings of the International Congress (12th), Corrosion Control for Low-Cost Reliability, Held in Houston, Texas on September 19 -24, 1993. Volume 1. Coatings

DTIC Science & Technology

1993-09-24

3]) Gas-cooled reactors were first developed in Europe and have been built since 1956. HTGR , equipped with the core of ceramic coated particle fuels ...demands must also be covered by nuclear energy in not so long future. Programs on developing the process heating HTGR have been promoted mainly in Germany...Material programs for HTGR have been promoted in several countries since late 1960’s which include the tasks of developing and qualifying materials, eg

Advances in drying: Volume 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mujumdar, A.S.

1987-01-01

Topics covered in this volume include recent thoughts in modeling of drying phenomena, use of computers in rational design of drying particulates, recent advances in drying of wood, and heat/mass transfer phenomena in drying of solids. As the readers will no doubt notice, special effort is made to ensure the truly international nature of the contents of this serial publication. As existing knowledge on drying and dryers becomes more widely and readily accessible, it is expected that more and more dryers will be designed rationally rather than built solely with the benefit of empiricism.

Selected technology for the gas industry

NASA Technical Reports Server (NTRS)

1975-01-01

A number of papers were presented at a conference concerned with the application of technical topics from aerospace activities for the gas industry. The following subjects were covered: general future of fossil fuels in America, exploration for fossil and nuclear fuels from orbital altitudes, technology for liquefied gas, safety considerations relative to fires, explosions, and detonations, gas turbomachinery technology, fluid properties, fluid flow, and heat transfer, NASA information and documentation systems, instrumentation and measurement, materials and life prediction, reliability and quality assurance, and advanced energy systems (including synthetic fuels, energy storage, solar energy, and wind energy).

Conversion of Low Quality Waste Heat to Electric Power with Small-Scale Organic Rankine Cycle (ORC) Engine/Generator Technology

DTIC Science & Technology

2016-08-01

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1...urrendy valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) , 2. REPORT TYPE 3. DATES COVERED (From...NUMBER (Include area code) 919-282-1050 Standard Form 298 (Rev. 8198) Pntscnbed by ANSI Std. Z39.18 Cost & Performance Report 58XX i COST

Gold ink coating of thermocouple sheaths

DOEpatents

Ruhl, H. Kenneth

1992-01-01

A method is provided for applying a gold ink coating to a thermocouple sheath which includes the steps of electropolishing and oxidizing the surface of the thermocouple sheath, then dipping the sheath into liquid gold ink, and finally heat curing the coating. The gold coating applied in this manner is highly reflective and does not degrade when used for an extended period of time in an environment having a temperature over 1000.degree. F. Depending on the application, a portion of the gold coating covering the tip of the thermocouple sheath is removed by abrasion.

10 CFR 431.408 - Preemption of State regulations for covered equipment other than electric motors and commercial...

Code of Federal Regulations, 2014 CFR

2014-01-01

... conservation standard, or water conservation standard (in the case of commercial prerinse spray valves or... other than electric motors and commercial heating, ventilating, air-conditioning and water heating products. 431.408 Section 431.408 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM...

49 CFR 176.305 - General stowage requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., protected from sources of heat, and away from potential sources of ignition. (b) Except as otherwise... following conditions exists: (i) The bulkhead or deck is covered with at least 8 cm (3 inches) of insulation on the entire area subject to heat; (ii) A temporary wooden bulkhead at least 5 cm (2 inches) thick...

49 CFR 176.305 - General stowage requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., protected from sources of heat, and away from potential sources of ignition. (b) Except as otherwise... following conditions exists: (i) The bulkhead or deck is covered with at least 8 cm (3 inches) of insulation on the entire area subject to heat; (ii) A temporary wooden bulkhead at least 5 cm (2 inches) thick...

A Self-Contained Cold Plate Utilizing Force-fed Evaporation for Cooling of High flux Electronics

DTIC Science & Technology

2007-01-01

additional improvement. The second advanced heat sink to be covered was developed and studied by Sung and Mudawar [27]. They created a hybrid jet...cooling by using manifold microchannel heat sinks.” Advanced Electronic Packaging. 2 (1997) 1837-1842. [27] Sung, M. K. & Mudawar , I

Schedules, technical status, and program activities in the development of a single family solar space heating system

NASA Technical Reports Server (NTRS)

1978-01-01

A collection of three quarterly reports are given covering the development of two prototype solar heating systems consisting of the following subsystems: collector, storage, control, transport, and site data acquisition. The two systems are being installed at York, Pennsylvania, and Manchester, New Hampshire.

A heat vulnerability index to improve urban public health management in San Juan, Puerto Rico.

PubMed

Méndez-Lázaro, Pablo; Muller-Karger, Frank E; Otis, Daniel; McCarthy, Matthew J; Rodríguez, Ernesto

2018-05-01

Increased frequency and length of high heat episodes are leading to more cardiovascular issues and asthmatic responses among the population of San Juan, the capital of the island of Puerto Rico, USA. An urban heat island effect, which leads to foci of higher temperatures in some urban areas, can raise heat-related mortality. The objective of this research is to map the risk of high temperature in particular locations by creating heat maps of the city of San Juan. The heat vulnerability index (HVI) maps were developed using images collected by satellite-based remote sensing combined with census data. Land surface temperature was assessed using images from the Thermal Infrared Sensor flown on Landsat 8. Social determinants (e.g., age, unemployment, education and social isolation, and health insurance coverage) were analyzed by census tract. The data were examined in the context of land cover maps generated using products from the Puerto Rico Terrestrial Gap Analysis Project (USDA Forest Service). All variables were set in order to transform the indicators expressed in different units into indices between 0 and 1, and the HVI was calculated as sum of score. The tract with highest index was considered to be the most vulnerable and the lowest to be the least vulnerable. Five vulnerability classes were mapped (very high, high, moderate, low, and very low). The hottest and the most vulnerable tracts corresponded to highly built areas, including the Luis Munoz International Airport, seaports, parking lots, and high-density residential areas. Several variables contributed to increased vulnerability, including higher rates of the population living alone, disabilities, advanced age, and lack of health insurance coverage. Coolest areas corresponded to vegetated landscapes and urban water bodies. The urban HVI map will be useful to health officers, emergency preparedness personnel, the National Weather Service, and San Juan residents, as it helps to prepare for and to mitigate the potential effects of heat-related illnesses.

A heat vulnerability index to improve urban public health management in San Juan, Puerto Rico

NASA Astrophysics Data System (ADS)

Méndez-Lázaro, Pablo; Muller-Karger, Frank E.; Otis, Daniel; McCarthy, Matthew J.; Rodríguez, Ernesto

2018-05-01

Increased frequency and length of high heat episodes are leading to more cardiovascular issues and asthmatic responses among the population of San Juan, the capital of the island of Puerto Rico, USA. An urban heat island effect, which leads to foci of higher temperatures in some urban areas, can raise heat-related mortality. The objective of this research is to map the risk of high temperature in particular locations by creating heat maps of the city of San Juan. The heat vulnerability index (HVI) maps were developed using images collected by satellite-based remote sensing combined with census data. Land surface temperature was assessed using images from the Thermal Infrared Sensor flown on Landsat 8. Social determinants (e.g., age, unemployment, education and social isolation, and health insurance coverage) were analyzed by census tract. The data were examined in the context of land cover maps generated using products from the Puerto Rico Terrestrial Gap Analysis Project (USDA Forest Service). All variables were set in order to transform the indicators expressed in different units into indices between 0 and 1, and the HVI was calculated as sum of score. The tract with highest index was considered to be the most vulnerable and the lowest to be the least vulnerable. Five vulnerability classes were mapped (very high, high, moderate, low, and very low). The hottest and the most vulnerable tracts corresponded to highly built areas, including the Luis Munoz International Airport, seaports, parking lots, and high-density residential areas. Several variables contributed to increased vulnerability, including higher rates of the population living alone, disabilities, advanced age, and lack of health insurance coverage. Coolest areas corresponded to vegetated landscapes and urban water bodies. The urban HVI map will be useful to health officers, emergency preparedness personnel, the National Weather Service, and San Juan residents, as it helps to prepare for and to mitigate the potential effects of heat-related illnesses.

A heat vulnerability index to improve urban public health management in San Juan, Puerto Rico

NASA Astrophysics Data System (ADS)

Méndez-Lázaro, Pablo; Muller-Karger, Frank E.; Otis, Daniel; McCarthy, Matthew J.; Rodríguez, Ernesto

2017-02-01

Increased frequency and length of high heat episodes are leading to more cardiovascular issues and asthmatic responses among the population of San Juan, the capital of the island of Puerto Rico, USA. An urban heat island effect, which leads to foci of higher temperatures in some urban areas, can raise heat-related mortality. The objective of this research is to map the risk of high temperature in particular locations by creating heat maps of the city of San Juan. The heat vulnerability index (HVI) maps were developed using images collected by satellite-based remote sensing combined with census data. Land surface temperature was assessed using images from the Thermal Infrared Sensor flown on Landsat 8. Social determinants (e.g., age, unemployment, education and social isolation, and health insurance coverage) were analyzed by census tract. The data were examined in the context of land cover maps generated using products from the Puerto Rico Terrestrial Gap Analysis Project (USDA Forest Service). All variables were set in order to transform the indicators expressed in different units into indices between 0 and 1, and the HVI was calculated as sum of score. The tract with highest index was considered to be the most vulnerable and the lowest to be the least vulnerable. Five vulnerability classes were mapped (very high, high, moderate, low, and very low). The hottest and the most vulnerable tracts corresponded to highly built areas, including the Luis Munoz International Airport, seaports, parking lots, and high-density residential areas. Several variables contributed to increased vulnerability, including higher rates of the population living alone, disabilities, advanced age, and lack of health insurance coverage. Coolest areas corresponded to vegetated landscapes and urban water bodies. The urban HVI map will be useful to health officers, emergency preparedness personnel, the National Weather Service, and San Juan residents, as it helps to prepare for and to mitigate the potential effects of heat-related illnesses.

Remote Sensing of Urban Thermal Landscape Characteristics and Their Affects on Local and Regional Meteorology and Air Quality: An Overview of NASA EOS-IDS Project Atlanta

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.; Luvall, Jeffrey C.; Estes, Maurice G., Jr.

1999-01-01

As an entity, the city is a manifestation of human "management" of the land. The act of city-building, however, drastically alters the biophysical environment, which ultimately, impacts local and regional land-atmosphere energy exchange processes. Because of the complexity of both the urban landscape and the attendant energy fluxes that result from urbanization, remote sensing offers the only real way to synoptically quantify these processes. One of the more important land-atmosphere fluxes that occurs over cities relates to the way that thermal energy is partitioned across the heterogeneous urban landscape. The individual land cover and surface material types that comprise the city, such as pavements and buildings, each have their own thermal energy regimes. As the collective urban landscape, the individual thermal energy responses from specific surfaces come together to form the urban heat island phenomena, which prevails as a dome of elevated air temperatures over cities. Although the urban heat island has been known to exist for well over 150 years, it is not understood how differences in thermal energy responses for land covers across the city interact to produce this phenomenon, or how the variability in thermal energy responses from different surface types drive its development. Additionally, it can be hypothesized that as cities grow in size through time, so do their urban heat islands. The interrelationships between urban sprawl and the respective growth of the urban heat island, however, have not been investigated. Moreover, little is known of the consequential effects of urban growth, land cover change, and the urban heat island as they impact local and regional meteorology and air quality.

The Racial/Ethnic Distribution of Heat Risk–Related Land Cover in Relation to Residential Segregation

PubMed Central

Morello-Frosch, Rachel; Cushing, Lara

2013-01-01

Objective: We examined the distribution of heat risk–related land cover (HRRLC) characteristics across racial/ethnic groups and degrees of residential segregation. Methods: Block group–level tree canopy and impervious surface estimates were derived from the 2001 National Land Cover Dataset for densely populated urban areas of the United States and Puerto Rico, and linked to demographic characteristics from the 2000 Census. Racial/ethnic groups in a given block group were considered to live in HRRLC if at least half their population experienced the absence of tree canopy and at least half of the ground was covered by impervious surface (roofs, driveways, sidewalks, roads). Residential segregation was characterized for metropolitan areas in the United States and Puerto Rico using the multigroup dissimilarity index. Results: After adjustment for ecoregion and precipitation, holding segregation level constant, non-Hispanic blacks were 52% more likely (95% CI: 37%, 69%), non-Hispanic Asians 32% more likely (95% CI: 18%, 47%), and Hispanics 21% more likely (95% CI: 8%, 35%) to live in HRRLC conditions compared with non-Hispanic whites. Within each racial/ethnic group, HRRLC conditions increased with increasing degrees of metropolitan area-level segregation. Further adjustment for home ownership and poverty did not substantially alter these results, but adjustment for population density and metropolitan area population attenuated the segregation effects, suggesting a mediating or confounding role. Conclusions: Land cover was associated with segregation within each racial/ethnic group, which may be explained partly by the concentration of racial/ethnic minorities into densely populated neighborhoods within larger, more segregated cities. In anticipation of greater frequency and duration of extreme heat events, climate change adaptation strategies, such as planting trees in urban areas, should explicitly incorporate an environmental justice framework that addresses racial/ethnic disparities in HRRLC. PMID:23694846

Infra-red and vibration tests of hybrid ablative/ceramic matrix technological breadboards for earth re-entry thermal protection systems

NASA Astrophysics Data System (ADS)

Barcena, Jorge; Garmendia, Iñaki; Triantou, Kostoula; Mergia, Konstatina; Perez, Beatriz; Florez, Sonia; Pinaud, Gregory; Bouilly, Jean-Marc; Fischer, Wolfgang P. P.

2017-05-01

A new thermal protection system for atmospheric earth re-entry is proposed. This concept combines the advantages of both reusable and ablative materials to establish a new hybrid concept with advanced capabilities. The solution consists of the design and the integration of a dual shield resulting on the overlapping of an external thin ablative layer with a Ceramic Matrix Composite (CMC) thermo-structural core. This low density ablative material covers the relatively small heat peak encountered during re-entry the CMC is not able to bear. On the other hand the big advantage of the CMC based TPS is of great benefit which can deal with the high integral heat for the bigger time period of the re-entry. To verify the solution a whole testing plan is envisaged, which as part of it includes thermal shock test by infra-red heating (heating flux up to 1 MW/m2) and vibration test under launcher conditions (Volna and Ariane 5). Sub-scale tile samples (100×100 mm2) representative of the whole system (dual ablator/ceramic layers, insulation, stand-offs) are specifically designed, assembled and tested (including the integration of thermocouples). Both the thermal and the vibration test are analysed numerically by simulation tools using Finite Element Models. The experimental results are in good agreement with the expected calculated parameters and moreover the solution is qualified according to the specified requirements.

Heat Production as a Tool in Geothermal Exploration

NASA Astrophysics Data System (ADS)

Rhodes, J. M.; Koteas, C.; Mabee, S. B.; Thomas, M.; Gagnon, T.

2012-12-01

Heat flow data (together with knowledge, or assumptions, of stratigraphy, thermal conductivity and heat production) provide the prime parameter for estimating the potential of geothermal resources. Unfortunately this information is expensive to obtain as it requires deep boreholes. Consequently it is sparse or lacking in areas not traditionally considered as having geothermal potential. New England (and most of the northeastern U.S.A.) is one such area. However, in the absence of volcano-derived hydrothermal activity with its attendant high heat flow, granitic plutons provide an alternative geothermal resource. Compared with other crustal rocks, granites contain higher concentrations of heat-producing elements (K, U, Th). Additionally, they are relatively homogeneous, compared to surrounding country rock, allowing for stimulation through hydro-fracking of large (>1 km3) geothermal reservoirs. Consequently we have adopted a different approach, obtaining heat production data rather then relying on the very sparse heat flow data. Birch and colleagues long since recognized the relationship between heat flow and heat production as an integral part of their concept of Heat Flow Provinces. Heat production is readily determined in the laboratory by measuring the density of a sample and the concentrations of its heat-producing elements potassium, uranium and thorium. We have determined the heat production for 570 samples from most of the major granitic and gneissic bodies in Massachusetts and Connecticut. We have also measured these parameters for 70 sedimentary rocks that cover granites and gneiss in the Connecticut and Narragansett Basins. This data is being used to calculate inferred heat flow data for these localities. Comparison of these inferred heat flow values with the sparse number of those measured directly in boreholes in the two States is encouraging, indicating that this approach has merit. We have also measured thermal conductivity on all of these samples. This, together with the measured heat production and the inferred heat flow allow the calculation of inferred temperature - depth profiles for these localities, from which we have produced maps showing the distribution of heat production, thermal conductivity, inferred heat flow and inferred temperatures at depths of 2, 4 and 6 km in the two States. We believe that this is a rapid and relatively cheap approach for evaluating the geothermal potential of a region lacking in heat flow data allowing identification of areas that warrant more detailed investigation which would include geophysical surveys and drilling. In Massachusetts and Connecticut such areas include the Fitchburg pluton, Permian granites and the Narragansett and Hartford Basins, where gneiss and granites are buried beneath Carboniferous and Triassic sediments respectively. This project is funded by the Department of Energy through an award to the Association of American State Geologists.

Development and Evaluation of Active Thermal Management System for Lithium-Ion Batteries using Solid-State Thermoelectric Heat Pump and Heat Pipes with Electric Vehicular Applications

NASA Astrophysics Data System (ADS)

Parekh, Bhaumik Kamlesh

Lithium-Ion batteries have become a popular choice for use in energy storage systems in electric vehicles (EV) and Hybrid electric vehicles (HEV) because of high power and high energy density. But the use of EV and HEV in all climates demands for a battery thermal management system (BTMS) since temperature effects their performance, cycle life and, safety. Hence the BTMS plays a crucial role in the performance of EV and HEV. In this paper, three thermal management systems are studied: (a) simple aluminum as heat spreader material, (b) heat pipes as heat spreader, and (c) advanced combined solid state thermoelectric heat pump (TE) and heat pipe system; these will be subsequently referred to as Design A, B and C, respectively. A detailed description of the designs and the experimental setup is presented. The experimental procedure is divided into two broad categories: Cooling mode and Warming-up mode. Cooling mode covers the conditions when a BTMS is responsible to cool the battery pack through heat dissipation and Warming-up mode covers the conditions when the BTMS is responsible to warm the battery pack in a low temperature ambient condition, maintaining a safe operating temperature of the battery pack in both modes. The experimental procedure analyzes the thermal management system by evaluating the effect of each variable like heat sink area, battery heat generation rate, cooling air temperature, air flow rate and TE power on parameters like maximum temperature of the battery pack (T max), maximum temperature difference (DeltaT) and, heat transfer through heat sink/cooling power of TE (Q c). The results show that Design C outperforms Design A and Design B in spite of design issues which reduce its efficiency, but can still be improved to achieve better performance.

Microwave power transmission system studies. Volume 2: Introduction, organization, environmental and spaceborne systems analyses

NASA Technical Reports Server (NTRS)

Maynard, O. E.; Brown, W. C.; Edwards, A.; Haley, J. T.; Meltz, G.; Howell, J. M.; Nathan, A.

1975-01-01

Introduction, organization, analyses, conclusions, and recommendations for each of the spaceborne subsystems are presented. Environmental effects - propagation analyses are presented with appendices covering radio wave diffraction by random ionospheric irregularities, self-focusing plasma instabilities and ohmic heating of the D-region. Analyses of dc to rf conversion subsystems and system considerations for both the amplitron and the klystron are included with appendices for the klystron covering cavity circuit calculations, output power of the solenoid-focused klystron, thermal control system, and confined flow focusing of a relativistic beam. The photovoltaic power source characteristics are discussed as they apply to interfacing with the power distribution flow paths, magnetic field interaction, dc to rf converter protection, power distribution including estimates for the power budget, weights, and costs. Analyses for the transmitting antenna consider the aperture illumination and size, with associated efficiencies and ground power distributions. Analyses of subarray types and dimensions, attitude error, flatness, phase error, subarray layout, frequency tolerance, attenuation, waveguide dimensional tolerances, mechanical including thermal considerations are included. Implications associated with transportation, assembly and packaging, attitude control and alignment are discussed. The phase front control subsystem, including both ground based pilot signal driven adaptive and ground command approaches with their associated phase errors, are analyzed.

Near-surface air temperature lapse rate in a humid mountainous terrain on the southern slopes of the eastern Himalayas

NASA Astrophysics Data System (ADS)

Kattel, Dambaru Ballab; Yao, Tandong; Panday, Prajjwal Kumar

2018-05-01

Based on climatic data from 18 stations on the southern slopes of the eastern Himalayas in Bhutan for the period from 1996 to 2009, this paper investigates monthly characteristics of the near-surface air temperature lapse rate (TLR). The station elevations used in this study range from 300 to 2760 m a. s. l. TLRs were evaluated using a linear regression model. The monthly values of maximum TLRs were always smaller than those of the minimum TLRs, which is in contrast to results from the surrounding mountainous regions. In this study, annual patterns of TLRs were somewhat consistent, particularly in the summer; during the other seasons, patterns contrasted to results from the southeastern Tibetan Plateau (China) and were almost comparable to results from Nepal. The shallowest observed values for TLRs in summer are due to intense latent heating at the higher elevation, associated with water vapor condensation from moist convection and evapotranspiration, and decreasing sensible heating at lower elevation, due to heavier rainfall, cloud, and forest cover. When compared to summer, the steeper TLRs in the non-monsoon season are due to sensible heating at the lower elevations, corresponding to dry and clear weather seasons, as well as increasing cooling at higher elevations, particularly in winter due to snow and cloud cover. Owing to lower albedo and higher aerodynamic roughness of forested areas, the TLRs were considerably reduced in daytime because of the dissipation of sensible heat to the atmospheric boundary layer. The distinct variation in diurnal TLR range is due to the diurnal variation in net radiation associated with reduced turbulent heating in the day and increased turbulent heating in the night, in addition to the effect of moisture and cloud cover. The shallower values of TLRs in this study when compared with the surrounding mountainous regions are due to high humidity, as well as the differing elevations and local climates.

Global map of heat flow on a 2 degree grid - digitally available

NASA Astrophysics Data System (ADS)

Davies, J. Huw

2014-05-01

A global map of surface heat flow is developed on a 2° by 2° equal area grid, and is made available digitally. It is based on a global heat flow data set of over 38,000 measurements, very similar to that used in Davies & Davies (2010). The map consists of three components. Firstly, in regions of young ocean crust (<67.7Ma) the model estimate uses a half-space conduction model based on the age of the oceanic crust, using parameters of Jaupart et al., (2007). This is done since it is well known that raw data measurements are frequently influenced by significant hydrothermal circulation. Secondly in other regions of data coverage the estimate is based on data measurements. At the map resolution these two categories (young ocean, data covered) cover 65% of Earth's surface. The estimate has been developed in two different ways. In one way the mean value is used and in the second the median is used. The median estimate might be expected to be less sensitive to outliers. Thirdly, for all other regions the estimate is based on the assumption that there is a correlation between heat-flow and geology. This is undertaken using the CCGM (2000) digital geology map. This assumption is assessed and the correlation is found to provide a minor improvement over assuming that heat flow would be represented by the global average. The estimate for Antarctica is guided by proxy measurements. All the work is undertaken using GIS methods. Estimates are made of the errors for all components. The results have been made available as digital files, including shapefiles and tab-delimited and csv ASCII files. In addition to the equal area grid, the results are also available on an equal longitude grid. The map has been published -Davies (2013). The digital files are available in the supplementary information of the publication. Commission for the Geological Map of the World (2000), Geological Map of the World at 1:25000000, UNESCO/CCGM, Paris. Davies, JH, (2013) A global map of solid Earth surface heat flow, Geochemistry, Geophysics and Geosystems, 14, 4608-4622, doi 10.1002/ggge.20271. Davies JH & Davies DR, (2010) Earth's surface heat flux, Solid Earth, 1, 5-24, www.solid-earth.net/1/5/2010/. Jaupart C, Labrosse S, Mareschal J-C, (2007) Temperatures, heat and energy in the mantle of the Earth, in Treatise on Geophysics, v7 Mantle Convection, ed D. Bercovici, 253-303, Elsevier, Amsterdam

Adhesion of Silicone Elastomer Seals for NASA's Crew Exploration Vehicle

NASA Technical Reports Server (NTRS)

deGroh, Henry C., III; Miller, Sharon K. R.; Smith, Ian M.; Daniels, Christopher C.; Steinetz, Bruce M

2008-01-01

Silicone rubber seals are being considered for a number of interfaces on NASA's Crew Exploration Vehicle (CEV). Some of these joints include the docking system, hatches, and heat shield-to-back shell interface. A large diameter molded silicone seal is being developed for the Low Impact Docking System (LIDS) that forms an effective seal between the CEV and International Space Station (ISS) and other future Constellation Program spacecraft. Seals between the heat shield and back shell prevent high temperature reentry gases from leaking into the interface. Silicone rubber seals being considered for these locations have inherent adhesive tendencies that would result in excessive forces required to separate the joints if left unchecked. This paper summarizes adhesion assessments for both as-received and adhesion-mitigated seals for the docking system and the heat shield interface location. Three silicone elastomers were examined: Parker Hannifin S0899-50 and S0383-70 compounds, and Esterline ELA-SA-401 compound. For the docking system application various levels of exposure to atomic oxygen (AO) were evaluated. Moderate AO treatments did not lower the adhesive properties of S0899-50 sufficiently. However, AO pretreatments of approximately 10(exp 20) atoms/sq cm did lower the adhesion of S0383-70 and ELA-SA-401 to acceptable levels. For the heat shield-to-back shell interface application, a fabric covering was also considered. Molding Nomex fabric into the heat shield pressure seal appreciably reduced seal adhesion for the heat shield-to-back shell interface application.

Numerical and experimental analysis of a thin liquid film on a rotating disk related to development of a spacecraft absorption cooling system

NASA Technical Reports Server (NTRS)

Faghri, Amir; Swanson, Theodore D.

1989-01-01

The numerical and experimental analysis of a thin liquid film on a rotating and a stationary disk related to the development of an absorber unit for a high capacity spacecraft absorption cooling system, is described. The creation of artificial gravity by the use of a centrifugal field was focused upon in this report. Areas covered include: (1) One-dimensional computation of thin liquid film flows; (2) Experimental measurement of film height and visualization of flow; (3) Two-dimensional computation of the free surface flow of a thin liquid film using a pressure optimization method; (4) Computation of heat transfer in two-dimensional thin film flow; (5) Development of a new computational methodology for the free surface flows using a permeable wall; (6) Analysis of fluid flow and heat transfer in a thin film in the presence and absence of gravity; and (7) Comparison of theoretical prediction and experimental data. The basic phenomena related to fluid flow and heat transfer on rotating systems reported here can also be applied to other areas of space systems.

[A method of temperature measurement for hot forging with surface oxide based on infrared spectroscopy].

PubMed

Zhang, Yu-cun; Qi, Yan-de; Fu, Xian-bin

2012-05-01

High temperature large forging is covered with a thick oxide during forging. It leads to a big measurement data error. In this paper, a method of measuring temperature based on infrared spectroscopy is presented. It can effectively eliminate the influence of surface oxide on the measurement of temperature. The method can measure the surface temperature and emissivity of the oxide directly using the infrared spectrum. The infrared spectrum is radiated from surface oxide of forging. Then it can derive the real temperature of hot forging covered with the oxide using the heat exchange equation. In order to greatly restrain interference spectroscopy through included in the received infrared radiation spectrum, three interference filter system was proposed, and a group of optimal gap parameter values using spectral simulation were obtained. The precision of temperature measurement was improved. The experimental results show that the method can accurately measure the surface temperature of high temperature forging covered with oxide. It meets the requirements of measurement accuracy, and the temperature measurement method is feasible according to the experiment result.

Recent Basal Melting of a Mid-Latitude Glacier on Mars

NASA Astrophysics Data System (ADS)

Butcher, Frances E. G.; Balme, M. R.; Gallagher, C.; Arnold, N. S.; Conway, S. J.; Hagermann, A.; Lewis, S. R.

2017-12-01

Evidence for past basal melting of young (late Amazonian-aged), debris-covered glaciers in Mars' mid-latitudes is extremely rare. Thus, it is widely thought that these viscous flow features (VFFs) have been perennially frozen to their beds. We identify an instance of recent, localized wet-based mid-latitude glaciation, evidenced by a candidate esker emerging from a VFF in a tectonic rift in Tempe Terra. Eskers are sedimentary ridges deposited in ice-walled meltwater conduits and are indicative of glacial melting. We compare the candidate esker to terrestrial analogues, present a geomorphic map of landforms in the rift, and develop a landsystem model to explain their formation. We propose that the candidate esker formed during a transient phase of wet-based glaciation. We then consider the similarity between the geologic setting of the new candidate esker and that of the only other candidate esker to be identified in association with an existing mid-latitude VFF; both are within tectonic graben/rifts proximal to volcanic provinces. Finally, we calculate potential basal temperatures for a range of VFF thicknesses, driving stresses, mean annual surface temperatures, and geothermal heat fluxes, which unlike previous studies, include the possible role of internal strain heating. Strain heating can form an important additional heat source, especially in flow convergence zones, or where ice is warmer due to elevated surface temperatures or geothermal heat flux. Elevated geothermal heat flux within rifts, perhaps combined with locally-elevated strain heating, may have permitted wet-based glaciation during the late Amazonian, when cold climates precluded more extensive wet-based glaciation on Mars.

Local Climate Changes Forced by Changes in Land Use and topography in the Aburrá Valley, Colombia.

NASA Astrophysics Data System (ADS)

Zapata Henao, M. Z.; Hoyos Ortiz, C. D.

2017-12-01

One of the challenges in the numerical weather models is the adequate representation of soil-vegetation-atmosphere interaction at different spatial scales, including scenarios with heterogeneous land cover and complex mountainous terrain. The interaction determines the energy, mass and momentum exchange at the surface and could affect different variables including precipitation, temperature and wind. In order to quantify the long-term climate impact of changes in local land use and to assess the role of topography, two numerical experiments were examined. The first experiment allows assessing the continuous growth of urban areas within the Aburrá Valley, a complex terrain region located in Colombian Andes. The Weather Research Forecast model (WRF) is used as the basis of the experiment. The basic setup involves two nested domains, one representing the continental scale (18 km) and the other the regional scale (2 km). The second experiment allows drastic topography modification, including changing the valley configuration to a plateau. The control run for both experiments corresponds to a climatological scenario. In both experiments the boundary conditions correspond to the climatological continental domain output. Surface temperature, surface winds and precipitation are used as the main variables to compare both experiments relative to the control run. The results of the first experiment show a strong relationship between land cover and the variables, specially for surface temperature and wind speed, due to the strong forcing land cover imposes on the albedo, heat capacity and surface roughness, changing temperature and wind speed magnitudes. The second experiment removes the winds spatial variability related with hill slopes, the direction and magnitude are modulated only by the trade winds and roughness of land cover.

Economics of installation of solar heating plants

NASA Astrophysics Data System (ADS)

Popel, O. S.; Frid, S. Y.; Shpiltayn, E. E.

1984-04-01

An engineering-economic analysis of solar heating plants for determination of their cost effectiveness involves calculating the maximum economically feasibile extra capital investment on their installation and calculating the fraction of the total heat demand covered by such a plant which makes replacement of conventional heating plant maximally economical. The annual economic effect of solar heating is calculated in terms of normalized cost differential, as criterion for its competitiveness with conventional heating. Plant performance characteristics, namely dependence of both the percent demand coverage and the annual cost differential on the area of solar radiation collectors is then considered. Analysis of the cost equation, assuming that the extra fixed cost is proportional to the collector area, reveals the necessary and sufficient condition for decrease of annual operating cost.

Pool boiling on surfaces with mini-fins and micro-cavities

NASA Astrophysics Data System (ADS)

Pastuszko, Robert; Piasecka, Magdalena

2012-11-01

The experimental studies presented here focused on pool boiling heat transfer on mini-fin arrays, mini-fins with perforated covering and surfaces with micro-cavities. The experiments were carried out for water and fluorinert FC-72 at atmospheric pressure. Mini-fins of 0.5 and 1 mm in height were uniformly spaced on the base surface. The copper foil with holes of 0.1 mm in diameter (pitch 0.2/0.4 mm), sintered with the fin tips, formed a system of connected perpendicular and horizontal tunnels. The micro-cavities were obtained through spark erosion. The maximal depth of the craters of these cavities was 15 - 30 μm and depended on the parameters of the branding-pen settings. At medium and small heat fluxes, structures with mini-fins showed the best boiling heat transfer performance both for water and FC-72. At medium and high heat fluxes (above 70 kW/m2 for water and 25 kW/m2 for FC-72), surfaces with mini-fins without porous covering and micro-cavities produced the highest heat transfer coefficients. The surfaces obtained with spark erosion require a proper selection of geometrical parameters for particular liquids - smaller diameters of cavities are suitable for liquids with lower surface tension (FC-72).

The effect of reduced gravity on cryogenic nitrogen boiling and pipe chilldown.

PubMed

Darr, Samuel; Dong, Jun; Glikin, Neil; Hartwig, Jason; Majumdar, Alok; Leclair, Andre; Chung, Jacob

2016-01-01

Manned deep space exploration will require cryogenic in-space propulsion. Yet, accurate prediction of cryogenic pipe flow boiling heat transfer is lacking, due to the absence of a cohesive reduced gravity data set covering the expected flow and thermodynamic parameter ranges needed to validate cryogenic two-phase heat transfer models. This work provides a wide range of cryogenic chilldown data aboard an aircraft flying parabolic trajectories to simulate reduced gravity. Liquid nitrogen is used to quench a 1.27 cm diameter tube from room temperature. The pressure, temperature, flow rate, and inlet conditions are reported from 10 tests covering liquid Reynolds number from 2,000 to 80,000 and pressures from 80 to 810 kPa. Corresponding terrestrial gravity tests were performed in upward, downward, and horizontal flow configurations to identify gravity and flow direction effects on chilldown. Film boiling heat transfer was lessened by up to 25% in reduced gravity, resulting in longer time and more liquid to quench the pipe to liquid temperatures. Heat transfer was enhanced by increasing the flow rate, and differences between reduced and terrestrial gravity diminished at high flow rates. The new data set will enable the development of accurate and robust heat transfer models of cryogenic pipe chilldown in reduced gravity.

The effect of reduced gravity on cryogenic nitrogen boiling and pipe chilldown

PubMed Central

Darr, Samuel; Dong, Jun; Glikin, Neil; Hartwig, Jason; Majumdar, Alok; Leclair, Andre; Chung, Jacob

2016-01-01

Manned deep space exploration will require cryogenic in-space propulsion. Yet, accurate prediction of cryogenic pipe flow boiling heat transfer is lacking, due to the absence of a cohesive reduced gravity data set covering the expected flow and thermodynamic parameter ranges needed to validate cryogenic two-phase heat transfer models. This work provides a wide range of cryogenic chilldown data aboard an aircraft flying parabolic trajectories to simulate reduced gravity. Liquid nitrogen is used to quench a 1.27 cm diameter tube from room temperature. The pressure, temperature, flow rate, and inlet conditions are reported from 10 tests covering liquid Reynolds number from 2,000 to 80,000 and pressures from 80 to 810 kPa. Corresponding terrestrial gravity tests were performed in upward, downward, and horizontal flow configurations to identify gravity and flow direction effects on chilldown. Film boiling heat transfer was lessened by up to 25% in reduced gravity, resulting in longer time and more liquid to quench the pipe to liquid temperatures. Heat transfer was enhanced by increasing the flow rate, and differences between reduced and terrestrial gravity diminished at high flow rates. The new data set will enable the development of accurate and robust heat transfer models of cryogenic pipe chilldown in reduced gravity. PMID:28725740

Investigation of heat transfer in cereal-based foam from a micro-scale perspective using the lattice Boltzmann method

NASA Astrophysics Data System (ADS)

Mack, Simone; Hussein, Mohamed A.; Becker, Thomas

2011-12-01

Foam materials are multicomponent and multiphase systems, where under the influence of heat several temperature-dependent processes occur. In cereal-based foams these processes include protein denaturation, starch gelatinization, phase changes such as water evaporation, and structural changes covering bubble expansion and coalescence. This research focuses on modeling heat transfer processes in cereal foams under thermal treatment from a microstructural point of view. The complex thermo-fluidic processes inside the foam are considered for the solid and the gaseous phase, respectively. Additionally, the microstructural foam characteristics are modified to establish their effect on the overall heat transfer rate, and the micro-scale dynamics are introduced by means of lattice Boltzmann methods (LBM). The objective of this study is to deliver sophisticated insight into the impact of structural properties, due to the fact that optimized parameters would help to improve the bakery industry by means of reduction in baking time, energy, and costs. The results show that altering the porosity and/or the interconnectivity of gas pores in bread crumb influences the overall heat transfer. In comparison to foams having a porosity of 55% and discrete pores, the impact of coalescence exhibits a reduction of baking time of about 2 min. Increasing the porosity about 20% results in reducing the baking time about 7 min.

[Clothing and heat disorder].

PubMed

Satsumoto, Yayoi

2012-06-01

The influence of the clothing material properties(like water absorbency and rapid dryness, water vapor absorption, water vapor permeability and air permeability) and the design factor of the clothing(like opening condition and fitting of clothing), which contributed to prevent heat disorder, was outlined. WBGT(wet-bulb globe temperature) is used to show a guideline for environmental limitation of activities to prevent heat disorder. As the safety function is more important than thermal comfort for some sportswear and protective clothing with high cover area, clothing itself increases the risk of heat disorder. WBGT is corrected by CAF (clothing adjustment factor) in wearing such kind of protective clothing.

Pilot Test of Hot Gas Decontamination of Explosives-Contaminated Equipment at Hawthorne Army Ammunition Plant (HWAAP), Hawthorne, Nevada. Appendices. Revision

DTIC Science & Technology

1990-06-01

was used to spike the following items of equipment: 0 powder boxes o steam-heated risers o steam-heated discharge valves o steel pipe o aluminum pipe...expose it to the internal surfaces. For pipe ( aluminum and steel), one end of the pipe section was covered with parafilm wax. Spike solution was added...spike the following items of equipment: "o powder box "o steam-heated riser "o steam-heated discharge valve "O steel pipe "o aluminum pipe Prior to

Turbulent Supersonic/Hypersonic Heating Correlations for Open and Closed Cavities

NASA Technical Reports Server (NTRS)

Everhart, Joel L.; Greene, Francis A.

2009-01-01

Supersonic/hypersonic laminar heating correlations that were developed for damage assessment analysis of atmospheric re-entry vehicles have been modified and extended to cover fully-turbulent conditions over rectangular cavity geometries that are aligned with the local velocity. Turbulent boundary layer properties were computationally determined and used to develop the cavity geometry parametrics and to correlate experimental closed cavity heating data to yield new relationships for the floor-averaged and centerline endwall peakheating augmentation. With the form of the closed-cavity correlations established, historical data were used to develop new correlations for turbulent open-cavity heating.

Aluminum runway surface as possible aid to aircraft braking

NASA Technical Reports Server (NTRS)

Miller, C. D.; Pinkel, I. I.

1973-01-01

Several concepts are described for use singly or in combination to improve aircraft braking. All involve a thin layer of aluminum covering all or part of the runway. Advantage would derive from faster heat conduction from the tire-runway interface. Heating of tread surface with consequent softening and loss of friction coefficient should be reduced. Equations are developed indicating that at least 99 percent of friction heat should flow into the aluminum. Preliminary test results indicate a coefficient of sliding friction of 1.4, with predictably slight heating of tread. Elimination of conventional brakes is at least a remote possibility.

Heat Flow and Hydrothermal Circulation of the Lucky Strike Segment, Mid Atlantic Ridge

NASA Astrophysics Data System (ADS)

Bonneville, A.; Escartin, J.; Lucazeau, F.; Cannat, M.; Gouze, P.; von Herzen, R. P.; Adam, C.; Le Bars, M.; Monoury, E.; Vidal, V.

2003-12-01

In June 2003, expedition Luckyflux aboard the R/V Poseidon conducted a heat flow survey of a zone centred on the Lucky Strike segment of the Mid Atlantic ridge south of the Azores between ˜35° N and 39° N. Using a 5 m-long lance with 7 outrigger thermal probes, about 150 successful thermal gradient measurements were obtained, 140 of these with in-situ thermal conductivity. Measurements were made at ˜1 mile intervals along several profiles, where adequately sedimented sites were identified using 6-channel and 3.5 kHz seismic data from the previous Sudazores'98 cruise. We conducted heat flow measurements in two areas: a near axis region within the V-shaped ridge of overthickened crust that emanated from the Azores hotspot between ˜14 and 4 Ma, and an off-axis region East of the V-shaped ridge. The off-axis region is characterized by an homogeneous sediment cover, 300-400 m thick, and crustal ages varying between ˜6 and >10 Ma. Long wavelength (tens of km) low heat flow anomalies can be identified but the mean of 160 mWm-2 is comparable to the conductive heat flow expected for a crust of that age. Along two 80-km profiles perpendicular to the ridge, we observed coherent but different patterns. On the first profile, low heat flow values of 20-50 mWm-2 are observed at the base of the V-shaped ridge. These values are 100 mWm-2 below the profile average, showing that hydrothermal circulations can also affect oceanic crust beneath a thick and relatively impermeable sediment cover. On the other profile, heat flow generally decreases from west to east. On both profiles, higher than average values of heat flow are also present, associated on one of them with a nearly outcropping basement elevation. These contrasting overall heat flow patterns in similar geological context indicate that the likely pattern of hydrothermal circulations is mainly 3D, and not driven only by the presence of basement outcrops. In the near-axis region, where the tectonic structure is more complicated and the sediment cover heterogeneous, heat flow data show no clear spatial variation and their mean value, 60 to 90 mWm-2, is systematically lower than theoretical conductive values for young seafloor. These heat flow differences will be used to estimate the importance of advection in the heat budget. This characterization of the regional thermal state around a slow-spreading segment will provide the basis for future long-term studies on the structure, thermal evolution and the hydrothermal systems within the MOMAR (MOnitoring the Mid Atlantic Ridge) project.

Commercial Buildings Energy Consumption Survey 2012 - Detailed Tables

EIA Publications

2016-01-01

The 2012 CBECS consumption and expenditures detailed tables are comprised of Tables C1-C38, which cover overall electricity, natural gas, fuel oil and district heat consumption, and tables E1-E11, which disaggregate the same energy sources by end use (heating, cooling, lighting, etc.). All of the detailed tables contain extensive row categories of building characteristics.

Energy fluxes estimation in a juniper tree area of the Donana biological reserve through TSEB method and Landsat-5TM imagery

USDA-ARS?s Scientific Manuscript database

Energy fluxes computing (actual evapotranspiration, net radiation, sensible heat and soil heat flux) are essential to improve the knowledge of the hydrological cycle, especially in natural vegetation covers. In this paper we present the first results of the energy fluxes modeling by means of the TSE...

49 CFR 176.305 - General stowage requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and be stowed away from all sources of heat and ignition. (b) Except as otherwise provided in § 176.76... following conditions exists: (i) The bulkhead or deck is covered with at least 8 cm (3 inches) of insulation on the entire area subject to heat; (ii) A temporary wooden bulkhead at least 5 cm (2 inches) thick...

49 CFR 176.305 - General stowage requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... and be stowed away from all sources of heat and ignition. (b) Except as otherwise provided in § 176.76... following conditions exists: (i) The bulkhead or deck is covered with at least 8 cm (3 inches) of insulation on the entire area subject to heat; (ii) A temporary wooden bulkhead at least 5 cm (2 inches) thick...

49 CFR 176.305 - General stowage requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and be stowed away from all sources of heat and ignition. (b) Except as otherwise provided in § 176.76... following conditions exists: (i) The bulkhead or deck is covered with at least 8 cm (3 inches) of insulation on the entire area subject to heat; (ii) A temporary wooden bulkhead at least 5 cm (2 inches) thick...

Principles of Refrigeration. Automotive Mechanics. Air Conditioning. Instructor's Guide [and] Student Guide.

ERIC Educational Resources Information Center

Spignesi, B.

This instructional package, one in a series of individualized instructional units on automobile air conditioning, consists of a student guide and an instructor guide dealing with the principles of refrigeration. Covered in the module are defining the term heat, defining the term British Thermal Unit (BTU), defining the term latent heat, listing…

75 FR 6013 - Energy Conservation Program for Consumer Products: Decision and Order Granting a Waiver to...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-05

... heating exceeds the high-stage compressor capacity for cooling. Finally, the test procedure must account... test method to cover Hallowell's three-capacity compressor. The two (of three potential) active stages... pumps for the heating mode as follows: a. Conduct one Maximum Temperature Test (H0 1 ), two High...

The long-term effect of urbanization and anthropogenic heat release on climate across China

NASA Astrophysics Data System (ADS)

Wang, Y.; Feng, J.

2013-12-01

The human activities impact on the urban heat island (UHI) is directly through anthropogenic heat release, and indirectly through the land use configuration. In this paper, the Weather Research and Forecasting (WRF) model coupled with the Urban Canopy Model (UCM) is employed to simulate the regional impacts on climate under the two scenarios in China: the underlying surface changes due to urbanization (USCU), and anthropogenic heat release (AHR). Three experiments were performed from January 2000 to February 2010. USCU decreases the summer and winter low cloud cover over most east China, and almost the energy flux increase except that the latent heat and the up solar wave, summer temperature increases obviously, particularly in the Beijing-Tianjin-Hebei and Yangtze River Delta region with an increase of 1.13°C and 1.22°C; AHR increases the variable change including the low cloud cover and all the energy flux and temperatures; the most striking winter temperature change region occurs also in the Yangtze River Delta region added by 0.63°C. USCU has the greatest impact on the summer precipitation in the Beijing-Tianjin-Hebei region, which has reduced amplitude value of 20.43 percent. The USCU decreases the surface soil humidity and increases the surface soil temperature in most east China. In the three urban agglomerations, summer surface wind increases apparently but winter surface wind reduce obviously affected by USCU. The low pressure level is the south wind with the amplitude less than 1m/s and the two cyclonic vorticity exists in the summer, there is the same wind direction in the winter, but without the apparent cyclonic vorticity and small wind speed under the USCU. In the AHR, the prevailing wind direction is north wind and two rise circulation between 30°N and 40°N in the summer, the principal winter wind direction is south with the same two rise circulation nearby former two latitude. The summer index almost increases under the USCU scenario, but AHR make it decrease.

Modelling the variation of land surface temperature as determinant of risk of heat-related health events

PubMed Central

2011-01-01

Background The evaluation of exposure to ambient temperatures in epidemiological studies has generally been based on records from meteorological stations which may not adequately represent local temperature variability. Here we propose a spatially explicit model to estimate local exposure to temperatures of large populations under various meteorological conditions based on satellite and meteorological data. Methods A general linear model was used to estimate surface temperatures using 15 LANDSAT 5 and LANDSAT 7 images for Quebec Province, Canada between 1987 and 2002 and spanning the months of June to August. The images encompassed both rural and urban landscapes and predictors included: meteorological records of temperature and wind speed, distance to major water bodies, Normalized Differential Vegetation Index (NDVI), land cover (built and bare land, water, or vegetation), latitude, longitude, and week of the year. Results The model explained 77% of the variance in surface temperature, accounting for both temporal and spatial variations. The standard error of estimates was 1.42°C. Land cover and NDVI were strong predictors of surface temperature. Conclusions This study suggests that a statistical approach to estimating surface temperature incorporating both spatially explicit satellite data and time-varying meteorological data may be relevant to assessing exposure to heat during the warm season in the Quebec. By allowing the estimation of space- and time-specific surface temperatures, this model may also be used to assess the possible impacts of land use changes under various meteorological conditions. It can be applied to assess heat exposure within a large population and at relatively fine-grained scale. It may be used to evaluate the acute health effect of heat exposure over long time frames. The method proposed here could be replicated in other areas around the globe for which satellite data and meteorological data is available. PMID:21251286

Micrometeorological simulations to predict the impacts of heat mitigation strategies on pedestrian thermal comfort in a Los Angeles neighborhood

NASA Astrophysics Data System (ADS)

Taleghani, Mohammad; Sailor, David; Ban-Weiss, George A.

2016-02-01

The urban heat island impacts the thermal comfort of pedestrians in cities. In this paper, the effects of four heat mitigation strategies on micrometeorology and the thermal comfort of pedestrians were simulated for a neighborhood in eastern Los Angeles County. The strategies investigated include solar reflective ‘cool roofs’, vegetative ‘green roofs’, solar reflective ‘cool pavements’, and increased street-level trees. A series of micrometeorological simulations for an extreme heat day were carried out assuming widespread adoption of each mitigation strategy. Comparing each simulation to the control simulation assuming current land cover for the neighborhood showed that additional street-trees and cool pavements reduced 1.5 m air temperature, while cool and green roofs mostly provided cooling at heights above pedestrian level. However, cool pavements increased reflected sunlight from the ground to pedestrians at a set of unshaded receptor locations. This reflected radiation intensified the mean radiant temperature and consequently increased physiological equivalent temperature (PET) by 2.2 °C during the day, reducing the thermal comfort of pedestrians. At another set of receptor locations that were on average 5 m from roadways and underneath preexisting tree cover, cool pavements caused significant reductions in surface air temperatures and small changes in mean radiant temperature during the day, leading to decreases in PET of 1.1 °C, and consequent improvements in thermal comfort. For improving thermal comfort of pedestrians during the afternoon in unshaded locations, adding street trees was found to be the most effective strategy. However, afternoon thermal comfort improvements in already shaded locations adjacent to streets were most significant for cool pavements. Green and cool roofs showed the lowest impact on the thermal comfort of pedestrians since they modify the energy balance at roof level, above the height of pedestrians.

Thermal Properties and Energy Fluxes in Pre-monsoon Season of 2016 at the Ponkar Debris-Covered Glacier, Manang, Nepal Himalaya

NASA Astrophysics Data System (ADS)

Chand, M. B.; Kayastha, R. B.; Armstrong, R. L.

2016-12-01

Himalayan glaciers are characterized by the presence of extensive debris cover in ablation areas. It is essential to understand the thermal properties and assess the effect of debris in glacier ice melt rate in debris-covered glaciers. Meteorological conditions are recorded on the lower ablation zone of the debris-covered Ponkar Glacier, Bhimthang, Manang, Nepal during pre-monsoon season of 2016. Debris temperature at different depths is monitored for winter and pre-monsoon season to estimate the effective heat conduction. Similarly, melt under the debris is also measured for pre-monsoon season. The incoming and outgoing shortwave radiations are measured at 2 m above the surface and other variables including air temperature, humidity, wind speed, and precipitation are used to estimate surface energy balance. Energy flux is dominated by net shortwave radiation as the foremost source of melting, where contribution of net longwave radiation, sensible, latent, and conductive heat flux is low. The daily average temperature gradients of the debris layer from surface to 30 cm below for winter and pre-monsoon seasons are 0.04 oC cm-1 and 0.23 oC cm-1, respectively. Debris thermal conductivities are 0.30 W m-1 K-1 and 1.69 W m-1 K-1 for the winter and pre-monsoon season, respectively. The higher value of conductivity during pre-monsoon season is due to the higher air temperature and increased precipitation compared to the winter months. The daily mean measured ice melt under a debris layer of 11-20 cm ranges from 0.6 to 1.1 cm. Estimation of melt at a few points can be used to estimate the general melting pattern for the glacier surface, which can be improved by using the spatial distribution of debris thickness and surface temperature.

A New Discrete Element Sea-Ice Model for Earth System Modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, Adrian Keith

Sea ice forms a frozen crust of sea water oating in high-latitude oceans. It is a critical component of the Earth system because its formation helps to drive the global thermohaline circulation, and its seasonal waxing and waning in the high north and Southern Ocean signi cantly affects planetary albedo. Usually 4{6% of Earth's marine surface is covered by sea ice at any one time, which limits the exchange of heat, momentum, and mass between the atmosphere and ocean in the polar realms. Snow accumulates on sea ice and inhibits its vertical growth, increases its albedo, and contributes to pooledmore » water in melt ponds that darken the Arctic ice surface in the spring. Ice extent and volume are subject to strong seasonal, inter-annual and hemispheric variations, and climatic trends, which Earth System Models (ESMs) are challenged to simulate accurately (Stroeve et al., 2012; Stocker et al., 2013). This is because there are strong coupled feedbacks across the atmosphere-ice-ocean boundary layers, including the ice-albedo feedback, whereby a reduced ice cover leads to increased upper ocean heating, further enhancing sea-ice melt and reducing incident solar radiation re ected back into the atmosphere (Perovich et al., 2008). A reduction in perennial Arctic sea-ice during the satellite era has been implicated in mid-latitude weather changes, including over North America (Overland et al., 2015). Meanwhile, most ESMs have been unable to simulate observed inter-annual variability and trends in Antarctic sea-ice extent during the same period (Gagne et al., 2014).« less

Electricity storage using a thermal storage scheme

NASA Astrophysics Data System (ADS)

White, Alexander

2015-01-01

The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater demand for large-scale electricity storage schemes. For example, the expanding fraction of electricity produced by wind turbines will require either backup or storage capacity to cover extended periods of wind lull. This paper describes a recently proposed storage scheme, referred to here as Pumped Thermal Storage (PTS), and which is based on "sensible heat" storage in large thermal reservoirs. During the charging phase, the system effectively operates as a high temperature-ratio heat pump, extracting heat from a cold reservoir and delivering heat to a hot one. In the discharge phase the processes are reversed and it operates as a heat engine. The round-trip efficiency is limited only by process irreversibilities (as opposed to Second Law limitations on the coefficient of performance and the thermal efficiency of the heat pump and heat engine respectively). PTS is currently being developed in both France and England. In both cases, the schemes operate on the Joule-Brayton (gas turbine) cycle, using argon as the working fluid. However, the French scheme proposes the use of turbomachinery for compression and expansion, whereas for that being developed in England reciprocating devices are proposed. The current paper focuses on the impact of the various process irreversibilities on the thermodynamic round-trip efficiency of the scheme. Consideration is given to compression and expansion losses and pressure losses (in pipe-work, valves and thermal reservoirs); heat transfer related irreversibility in the thermal reservoirs is discussed but not included in the analysis. Results are presented demonstrating how the various loss parameters and operating conditions influence the overall performance.

[Monitoring early toxicity of heavy metals including Hg using a HSE-SEAP reporter gene].

PubMed

Yu, Zhan-Jiang; Yang, Qin; Yang, Xiao-Da; Wang, Kui

2006-08-01

To develop a cellular assay based on heat shock signal pathway and secreted alkaline phosphatase (SEAP) reporter gene for investigating/predicting the early toxicity of heavy metals on HeLa cells in Chinese traditional medicine (TCM). The pHSE-SEAP plasmid was transfected into HeLa cells to build a HSE-SEAP-HeLa cell model. For validation of the model, the transfected cells were treated by either heating at 42 degrees C for 1 h or incubated with 5 mol x L(-1) CdCl2 for 4 h. Then the cells were covered in complete DMEM culture medium for 48 h and the activity of SEAP (reflecting the cellular level of heat shock protein) in cultural supernatants was measured; meanwhile, cell viability was determined by MTT assays. In addition, the cells were treated by four mercury compounds, HgCl2, merthilate sodium, HgS and cinnabar at the sub-lethal concentrations (determined by MTT assays). Then the heat shock response was detected likewise. Significant level of secreted alkaline phosphatase (SEAP) was found in pHSE-SEAP transfected HeLa cells treated either by heating (42 degrees C) or incubating with CdCl2. The heat shock protein was induced by CdCl2 before decrease of cell viability was observed. All four mercury compounds induced heat shock response in both time and concentration-dependant manner. However, there were big differences among the mercury compounds, suggesting potential differences for early-stage toxicity in vivo. The pHSE-SEAP transfected HeLa cells respond effectively to heat shock and metal stresses, and therefore provide a practical and repeatable assay for investigating/predicting the early toxicity of heavy metals and mineral-containing drugs in TCM.

Radiative energy balance of the Venus mesosphere

NASA Astrophysics Data System (ADS)

Haus, R.; Goering, H.

1990-03-01

An accurate radiative transfer model for line-by-line gaseous absorption, as well as for cloud absorption and multiple scattering, is used in the present calculation of solar heating and thermal cooling rates for standard temperature profiles and temperatures yielded by the Venera 15 Fourier Spectrometer Experiment. A strong dependency is noted for heating and cooling rates on cloud-structure variations. The Venus mesosphere is characterized by main cloud-cover heating and overlying-haze cooling. These results are applicable to Venus atmosphere dynamical models.

Building heating and cooling applications thermal energy storage program overview

NASA Technical Reports Server (NTRS)

Eissenberg, D. M.

1980-01-01

Thermal energy storage technology and development of building heating and cooling applications in the residential and commercial sectors is outlined. Three elements are identified to undergo an applications assessment, technology development, and demonstration. Emphasis is given to utility load management thermal energy system application where the stress is on the 'customer side of the meter'. Thermal storage subsystems for space conditioning and conservation means of increased thermal mass within the building envelope and by means of low-grade waste heat recovery are covered.

The Role and Variability of Ocean Heat Content in the Arctic Ocean: 1948-2009

DTIC Science & Technology

2014-06-01

moved from the Bering Sea past the Bering Strait into the Beaufort Sea (Logerwell 2008). However, besides the risks of ocean acidification and...VARIABILITY OF OCEAN HEAT CONTENT IN THE ARCTIC OCEAN : 1948–2009 by Dominic F. DiMaggio June 2014 Thesis Co-Advisors: Wieslaw Maslowski...COVERED Master’s Thesis 4. TITLE AND SUBTITLE THE ROLE AND VARIABILITY OF OCEAN HEAT CONTENT IN THE ARCTIC OCEAN : 1948–2009 5. FUNDING NUMBERS 6

Waste heat generation: A comprehensive review.

PubMed

Yeşiller, Nazli; Hanson, James L; Yee, Emma H

2015-08-01

A comprehensive review of heat generation in various types of wastes and of the thermal regime of waste containment facilities is provided in this paper. Municipal solid waste (MSW), MSW incineration ash, and mining wastes were included in the analysis. Spatial and temporal variations of waste temperatures, thermal gradients, thermal properties of wastes, average temperature differentials, and heat generation values are provided. Heat generation was influenced by climatic conditions, mean annual earth temperatures, waste temperatures at the time of placement, cover conditions, and inherent heat generation potential of the specific wastes. Time to onset of heat generation varied between months and years, whereas timelines for overall duration of heat generation varied between years and decades. For MSW, measured waste temperatures were as high as 60-90°C and as low as -6°C. MSW incinerator ash temperatures varied between 5 and 87°C. Mining waste temperatures were in the range of -25 to 65°C. In the wastes analyzed, upward heat flow toward the surface was more prominent than downward heat flow toward the subsurface. Thermal gradients generally were higher for MSW and incinerator ash and lower for mining waste. Based on thermal properties, MSW had insulative qualities (low thermal conductivity), while mining wastes typically were relatively conductive (high thermal conductivity) with ash having intermediate qualities. Heat generation values ranged from -8.6 to 83.1MJ/m(3) and from 0.6 to 72.6MJ/m(3) for MSW and mining waste, respectively and was 72.6MJ/m(3) for ash waste. Conductive thermal losses were determined to range from 13 to 1111MJ/m(3)yr. The data and analysis provided in this review paper can be used in the investigation of heat generation and thermal regime of a wide range of wastes and waste containment facilities located in different climatic regions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of a solar receiver for an organic Rankine cycle engine

NASA Astrophysics Data System (ADS)

Haskins, H. J.; Taylor, R. M.; Osborn, D. B.

A prototype power conversion assembly (PCA) developed by an American aerospace company is considered. The PCA will be mounted at the focal point of a 12 meter parabolic dish and will produce approximately 20 kW of 3 kHz ac power to a ground-mounted rectifier. The PCA includes a cavity receiver coupled to an organic Rankine cycle engine. The engine working fluid is toluene. The performance goals of the receiver design are to maximize both the thermal efficiency and the heat capacity of the core. The latter goal is desired for stabilizing the PCA operation during intermittent cloud cover. The receiver design is based upon the utilization of a direct-heated copper shell. It was necessary to develop a feasible manufacturing process for assuring a good braze joint between the stainless steel, containing the toluene, and the copper shell.

Development of a solar receiver for an organic Rankine cycle engine

NASA Technical Reports Server (NTRS)

Haskins, H. J.; Taylor, R. M.; Osborn, D. B.

1981-01-01

A prototype power conversion assembly (PCA) developed by an American aerospace company is considered. The PCA will be mounted at the focal point of a 12 meter parabolic dish and will produce approximately 20 kW of 3 kHz ac power to a ground-mounted rectifier. The PCA includes a cavity receiver coupled to an organic Rankine cycle engine. The engine working fluid is toluene. The performance goals of the receiver design are to maximize both the thermal efficiency and the heat capacity of the core. The latter goal is desired for stabilizing the PCA operation during intermittent cloud cover. The receiver design is based upon the utilization of a direct-heated copper shell. It was necessary to develop a feasible manufacturing process for assuring a good braze joint between the stainless steel, containing the toluene, and the copper shell.

Space imaging of a 300 years old cooling magma chamber: Timanfaya volcano (Lanzarote, Canary Islands)

NASA Astrophysics Data System (ADS)

Gonzalez, P. J.; Tiampo, K. F.

2010-12-01

Multitemporal space radar interferometry analysis between 1992 and 2000 revealed significantly deforming areas with a magnitude of 4-6 mm/yr of lengthening in the radar line of sight at Timanfaya volcano (Lanzarote, Canary Island). Timanfaya volcano erupted almost 300 years ago (1730-1736), along a 15 km-long fissure-feeding magmatic system, resulting in the longest and largest historical eruption of the Canarian archipelago to date, with >1 km3 of erupted basaltic lavas covering 200 km2. High surficial temperature (600 degrees-C at 13 m) and high heat flux measurements (150 mW/m2) suggest that the remnants of the magmatic chamber that fed the 1730-1736 are still partly molten. Here, we present preliminary models of the subsidence taking into account all available data, including geophysical data (heat flux, seismic, magnetotelluric and gravity), the geochemistry of freshly erupted lavas, upper mantle and crustal xenoliths, and structural geology.

Computer modeling of thermoelectric generator performance

NASA Technical Reports Server (NTRS)

Chmielewski, A. B.; Shields, V.

1982-01-01

Features of the DEGRA 2 computer code for simulating the operations of a spacecraft thermoelectric generator are described. The code models the physical processes occurring during operation. Input variables include the thermoelectric couple geometry and composition, the thermoelectric materials' properties, interfaces and insulation in the thermopile, the heat source characteristics, mission trajectory, and generator electrical requirements. Time steps can be specified and sublimation of the leg and hot shoe is accounted for, as are shorts between legs. Calculations are performed for conduction, Peltier, Thomson, and Joule heating, the cold junction can be adjusted for solar radition, and the legs of the thermoelectric couple are segmented to enhance the approximation accuracy. A trial run covering 18 couple modules yielded data with 0.3% accuracy with regard to test data. The model has been successful with selenide materials, SiGe, and SiN4, with output of all critical operational variables.

Preliminary evaluation of glass resin materials for solar cell cover use. [on spacecraft

NASA Technical Reports Server (NTRS)

Marsik, S. J.; Swartz, C. K.; Baraona, C. R.

1978-01-01

Silicon solar cells and silicon wafers coated with a heat-curable resin consisting of alternating Si-O atoms were subjected to three tests to evaluate the potential utility of this coating in space environments. These included UV irradiation in vacuum at an intensity of 10 air mass zero UV energy-equivalent solar constants for 728 hours followed by a long thermal cycle; 15 thermal shock cycles between 100 C and minus 196 C; and high temperature and humidity (65 C at 90% relative humidity). The UV tests resulted in a 8 to 24% loss in short-circuit current and darkening of the covers. Modification of the resin to provide a better match between the coefficients of expansion of the resin and silicon improved resistance to thermal shock, but also increased the darkening effect under UV irradiation. Silicon wafers coated with the resin were not adversely affected by the temperature/humidity test.

International contributions to IAEA-NEA heat transfer databases for supercritical fluids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leung, L. K. H.; Yamada, K.

2012-07-01

An IAEA Coordinated Research Project on 'Heat Transfer Behaviour and Thermohydraulics Code Testing for SCWRs' is being conducted to facilitate collaboration and interaction among participants from 15 organizations. While the project covers several key technology areas relevant to the development of SCWR concepts, it focuses mainly on the heat transfer aspect, which has been identified as the most challenging. Through the collaborating effort, large heat-transfer databases have been compiled for supercritical water and surrogate fluids in tubes, annuli, and bundle subassemblies of various orientations over a wide range of flow conditions. Assessments of several supercritical heat-transfer correlations were performed usingmore » the complied databases. The assessment results are presented. (authors)« less

Modeling of transient heat pipe operation

NASA Technical Reports Server (NTRS)

Colwell, Gene T.

1987-01-01

The use of heat pipes is being considered as a means of reducing the peak temperature and large thermal gradients at the leading edges of reentry vehicles and hypersonic aircraft and in nuclear reactors. In the basic cooling concept, the heat pipe covers the leading edge, a portion of the lower wing surface, and a portion of the upper wing surface. Aerodynamic heat is mainly absorbed at the leading edge and transported through the heat pipe to the upper and lower wing surface, where it is rejected by thermal radiation and convection. Basic governing equations are written to determine the startup, transient, and steady state performance of a haet pipe which has initially frozen alkali-metal as the working fluid.

Nonlinear Gravitational and Radiation Aspects in Nanoliquid with Exponential Space Dependent Heat Source and Variable Viscosity

NASA Astrophysics Data System (ADS)

Gireesha, B. J.; Kumar, P. B. Sampath; Mahanthesh, B.; Shehzad, S. A.; Abbasi, F. M.

2018-05-01

The nonlinear convective flow of kerosene-Alumina nanoliquid subjected to an exponential space dependent heat source and temperature dependent viscosity is investigated here. This study is focuses on augmentation of heat transport rate in liquid propellant rocket engine. The kerosene-Alumina nanoliquid is considered as the regenerative coolant. Aspects of radiation and viscous dissipation are also covered. Relevant nonlinear system is solved numerically via RK based shooting scheme. Diverse flow fields are computed and examined for distinct governing variables. We figured out that the nanoliquid's temperature increased due to space dependent heat source and radiation aspects. The heat transfer rate is higher in case of changeable viscosity than constant viscosity.

Nonlinear Gravitational and Radiation Aspects in Nanoliquid with Exponential Space Dependent Heat Source and Variable Viscosity

NASA Astrophysics Data System (ADS)

Gireesha, B. J.; Kumar, P. B. Sampath; Mahanthesh, B.; Shehzad, S. A.; Abbasi, F. M.

2018-02-01

The nonlinear convective flow of kerosene-Alumina nanoliquid subjected to an exponential space dependent heat source and temperature dependent viscosity is investigated here. This study is focuses on augmentation of heat transport rate in liquid propellant rocket engine. The kerosene-Alumina nanoliquid is considered as the regenerative coolant. Aspects of radiation and viscous dissipation are also covered. Relevant nonlinear system is solved numerically via RK based shooting scheme. Diverse flow fields are computed and examined for distinct governing variables. We figured out that the nanoliquid's temperature increased due to space dependent heat source and radiation aspects. The heat transfer rate is higher in case of changeable viscosity than constant viscosity.

Improved silicon carbide for advanced heat engines

NASA Technical Reports Server (NTRS)

Whalen, Thomas J.

1987-01-01

This is the second annual technical report entitled, Improved Silicon Carbide for Advanced Heat Engines, and includes work performed during the period February 16, 1986 to February 15, 1987. The program is conducted for NASA under contract NAS3-24384. The objective is the development of high strength, high reliability silicon carbide parts with complex shapes suitable for use in advanced heat engines. The fabrication methods used are to be adaptable for mass production of such parts on an economically sound basis. Injection molding is the forming method selected. This objective is to be accomplished in a two-phase program: (1) to achieve a 20 percent improvement in strength and a 100 percent increase in Weibull modulus of the baseline material; and (2) to produce a complex shaped part, a gas turbine rotor, for example, with the improved mechanical properties attained in the first phase. Eight tasks are included in the first phase covering the characterization of the properties of a baseline material, the improvement of those properties and the fabrication of complex shaped parts. Activities during the first contract year concentrated on two of these areas: fabrication and characterization of the baseline material (Task 1) and improvement of material and processes (Task 7). Activities during the second contract year included an MOR bar matrix study to improve mechanical properties (Task 2), materials and process improvements (Task 7), and a Ford-funded task to mold a turbocharger rotor with an improved material (Task 8).

A new stereo topographic map of Io: Implications for geology from global to local scales

NASA Astrophysics Data System (ADS)

White, Oliver L.; Schenk, Paul M.; Nimmo, Francis; Hoogenboom, Trudi

2014-06-01

We use Voyager and Galileo stereo pairs to construct the most complete stereo digital elevation model (DEM) of Io assembled to date, controlled using Galileo limb profiles. Given the difficulty of applying these two techniques to Io due to its anomalous surface albedo properties, we have experimented extensively with the relevant procedures in order to generate what we consider to be the most reliable DEMs. Our final stereo DEM covers ~75% of the globe, and we have identified a partial system of longitudinally arranged alternating basins and swells that correlates well to the distribution of mountain and volcano concentrations. We consider the correlation of swells to volcano concentrations and basins to mountain concentrations, to imply a heat flow distribution across Io that is consistent with the asthenospheric tidal heating model of Tackley et al. (2001). The stereo DEM reveals topographic signatures of regional-scale features including Loki Patera, Ra Patera, and the Tvashtar Paterae complex, in addition to previously unrecognized features including an ~1000 km diameter depression and a >2000 km long topographic arc comprising mountainous and layered plains material.

Dual-frequency ultrasound focal therapy for MRI-guided transurethral treatment of the prostate: Study in gel phantom

NASA Astrophysics Data System (ADS)

N'Djin, W. Apoutou; Mougenot, Charles; Kobelevskiy, Ilya; Ramsay, Elizabeth; Bronskill, Michael; Chopra, Rajiv

2012-11-01

Ultrasound thermal therapy of localized prostate cancer offers a minimally-invasive non-ionizing alternative [1-3] to surgery and radiotherapy. MRI-controlled transurethral ultrasound prostate therapy [4-6] has previously been investigated in a pilot human feasibility study [7], by treating a small sub-volume of prostate tissue. In this study, the feasibility of transurethral dual-frequency ultrasound focal therapy has been investigated in gel phantom. A database of pelvic anatomical models of human prostate cancer patients have been created using MR clinical images. The largest prostate boundary (47 cm3) was used to fabricate an anatomical gel phantom which included various MR characteristics to mimic prostate tissues, 4 localized tumors and surrounding prostate tissues. A 9-element transurethral ultrasound applicator working in dual-frequency mode (f = 4.6/14.5 MHz) was evaluated to heat: (i) the entire prostate volume (Full prostate treatment strategy), (ii) a prostate region restricted to tumors (Focal therapy). Acoustic power of each element and rotation rate of the device were adjusted in realtime based on MR-thermometry feedback control (nine thermal slices updated every 6.2s). Experiments have been performed using dual-frequency ultrasound exposures (surface Pmax: 20W.cm-2). (i) For full prostate heating, 7 elements of the device were used to cover the entire prostate length. The heating process was completed within 35 min. Ultrasound exposures at the fundamental frequency allowed full heating of the largest prostate radii (>18 mm), while exposures at the 3rd harmonic ensured homogeneous treatment of the smallest radii. Undertreated and overtreated regions represented respectively 2% and 17% of the prostate volume. (ii) For focal therapy, the target region was optimized to maintain safe regions in the prostate and to cover all tumor-mimics. Only 5 ultrasound elements were used to treat successfully all tumor-mimics within 26 min. Undertreated and overtreated regions each represented 7% of the prostate volume. MRI-guided transurethral ultrasound procedure enables full treatment and focal therapy in human prostate geometry. Prostate volume heating was fast compared to standard HIFU prostate treatments. Dual-frequency ultrasound exposures allowed optimal heat deposition in all prostate regions. The focal therapy strategy is promising as regard to safety and could contribute to enhance the post-treatment autonomy of the patient.

Evaluation of Hybrid Power Plants using Biomass, Photovoltaics and Steam Electrolysis for Hydrogen and Power Generation

NASA Astrophysics Data System (ADS)

Petrakopoulou, F.; Sanz, J.

2014-12-01

Steam electrolysis is a promising process of large-scale centralized hydrogen production, while it is also considered an excellent option for the efficient use of renewable solar and geothermal energy resources. This work studies the operation of an intermediate temperature steam electrolyzer (ITSE) and its incorporation into hybrid power plants that include biomass combustion and photovoltaic panels (PV). The plants generate both electricity and hydrogen. The reference -biomass- power plant and four variations of a hybrid biomass-PV incorporating the reference biomass plant and the ITSE are simulated and evaluated using exergetic analysis. The variations of the hybrid power plants are associated with (1) the air recirculation from the electrolyzer to the biomass power plant, (2) the elimination of the sweep gas of the electrolyzer, (3) the replacement of two electric heaters with gas/gas heat exchangers, and (4) the replacement two heat exchangers of the reference electrolyzer unit with one heat exchanger that uses steam from the biomass power plant. In all cases, 60% of the electricity required in the electrolyzer is covered by the biomass plant and 40% by the photovoltaic panels. When comparing the hybrid plants with the reference biomass power plant that has identical operation and structure as that incorporated in the hybrid plants, we observe an efficiency decrease that varies depending on the scenario. The efficiency decrease stems mainly from the low effectiveness of the photovoltaic panels (14.4%). When comparing the hybrid scenarios, we see that the elimination of the sweep gas decreases the power consumption due to the elimination of the compressor used to cover the pressure losses of the filter, the heat exchangers and the electrolyzer. Nevertheless, if the sweep gas is used to preheat the air entering the boiler of the biomass power plant, the efficiency of the plant increases. When replacing the electric heaters with gas-gas heat exchangers, the efficiency of the plant increases, although the higher pressure losses of the flue-gas path increase the requirements of the air compressor. Finally, replacing the two heat exchangers of the electrolyzer unit with one that uses extracted steam from the biomass power plant can lead to an overall decrease in the operating and investment costs of the plant.

Joint observations of solar corona in space projects ARKA and KORTES

NASA Astrophysics Data System (ADS)

Vishnyakov, Eugene A.; Bogachev, Sergey A.; Kirichenko, Alexey S.; Reva, Anton A.; Loboda, Ivan P.; Malyshev, Ilya V.; Ulyanov, Artem S.; Dyatkov, Sergey Yu.; Erkhova, Nataliya F.; Pertsov, Andrei A.; Kuzin, Sergey V.

2017-05-01

ARKA and KORTES are two upcoming solar space missions in extreme ultraviolet and X-ray wavebands. KORTES is a sun-oriented mission designed for the Russian segment of International Space Station. KORTES consists of several imaging and spectroscopic instruments that will observe the solar corona in a number of wavebands, covering EUV and X-ray ranges. The surveillance strategy of KORTES is to cover a wide range of observations including simultaneous imaging, spectroscopic and polarization measurements. ARKA is a small satellite solar mission intended to take highresolution images of the Sun at the extreme ultraviolet wavelengths. ARKA will be equipped with two high-resolution EUV telescopes designed to collect images of the Sun with approximately 150 km spatial resolution in the field of view of about 10'×10'. The scientific results of the mission may have a significant impact on the theory of coronal heating and may help to clarify the physics of small-scale solar structures and phenomena including oscillations of fine coronal structures and the physics of micro- and nanoflares.

Reconstructed Historical Land Cover and Biophysical Parameters for Studies of Land-Atmosphere Interactions within the Eastern United States

NASA Technical Reports Server (NTRS)

Steyaert, Louis T.; Knox, Robert G.

2007-01-01

The local environment where we live within the Earth's biosphere is often taken for granted. This environment can vary depending on whether the land cover is a forest, grassland, wetland, water body, bare soil, pastureland, agricultural field, village, residential suburb, or an urban complex with concrete, asphalt, and large buildings. In general, the type and characteristics of land cover influence surface temperatures, sunlight exposure and duration, relative humidity, wind speed and direction, soil moisture amount, plant life, birds, and other wildlife in our backyards. The physical and biological properties (biophysical characteristics) of land cover help to determine our surface environment because they directly affect surface radiation, heat, and soil moisture processes, and also feedback to regional weather and climate. Depending on the spatial scale and land use intensity, land cover changes can have profound impacts on our local and regional environment. Over the past 350 years, the eastern half of the United States, an area extending from the grassland prairies of the Great Plains to the Gulf and Atlantic coasts, has experienced extensive land cover and land use changes that began with land clearing in the 1600s, led to extensive deforestation and intensive land use practices by 1920, and then evolved to the present-day landscape. Determining the consequences of such land cover changes on regional and global climate is a major research issue. Such research requires detailed historical land cover data and modeling experiments simulating historical climates. Given the need to understand the effects of historical land cover changes in the eastern United States, some questions include: - What were the most important land cover transformations and how did they alter biophysical characteristics of the land cover at key points in time since the mid-1600s? - How have land cover and land use changes over the past 350 years affected the land surface environment including surface weather, hydrologic, and climatic variability? - How do the potential effects of regional human-induced land cover change on the environment compare to similar changes that are caused by the natural variations of the Earth's climate system? To help answer these questions, we reconstructed a fractional land cover and biophysical parameter dataset for the eastern United States at 1650, 1850, 1920, and 1992 time-slices. Each land cover fraction is associated with a biophysical parameter class, a suite of parameters defining the biophysical characteristics of that kind of land cover. This new dataset is designed for use in computer models of land-atmosphere interactions, to understand and quantify the effects of historical land cover changes on the water, energy, and carbon cycles

Comparison of forced-air warming systems with lower body blankets using a copper manikin of the human body.

PubMed

Bräuer, A; English, M J M; Lorenz, N; Steinmetz, N; Perl, T; Braun, U; Weyland, W

2003-01-01

Forced-air warming has gained high acceptance as a measure for the prevention of intraoperative hypothermia. However, data on heat transfer with lower body blankets are not yet available. This study was conducted to determine the heat transfer efficacy of six complete lower body warming systems. Heat transfer of forced-air warmers can be described as follows:[1]Qdot;=h.DeltaT.A where Qdot; = heat transfer [W], h = heat exchange coefficient [W m-2 degrees C-1], DeltaT = temperature gradient between blanket and surface [ degrees C], A = covered area [m2]. We tested the following forced-air warmers in a previously validated copper manikin of the human body: (1) Bair Hugger and lower body blanket (Augustine Medical Inc., Eden Prairie, MN); (2) Thermacare and lower body blanket (Gaymar Industries, Orchard Park, NY); (3) WarmAir and lower body blanket (Cincinnati Sub-Zero Products, Cincinnati, OH); (4) Warm-Gard(R) and lower body blanket (Luis Gibeck AB, Upplands Väsby, Sweden); (5) Warm-Gard and reusable lower body blanket (Luis Gibeck AB); and (6) WarmTouch and lower body blanket (Mallinckrodt Medical Inc., St. Luis, MO). Heat flux and surface temperature were measured with 16 calibrated heat flux transducers. Blanket temperature was measured using 16 thermocouples. DeltaT was varied between -10 and +10 degrees C and h was determined by a linear regression analysis as the slope of DeltaT vs. heat flux. Mean DeltaT was determined for surface temperatures between 36 and 38 degrees C, because similar mean skin temperatures have been found in volunteers. The area covered by the blankets was estimated to be 0.54 m2. Heat transfer from the blanket to the manikin was different for surface temperatures between 36 degrees C and 38 degrees C. At a surface temperature of 36 degrees C the heat transfer was higher (between 13.4 W to 18.3 W) than at surface temperatures of 38 degrees C (8-11.5 W). The highest heat transfer was delivered by the Thermacare system (8.3-18.3 W), the lowest heat transfer was delivered by the Warm-Gard system with the single use blanket (8-13.4 W). The heat exchange coefficient varied between 12.5 W m-2 degrees C-1 and 30.8 W m-2 degrees C-1, mean DeltaT varied between 1.04 degrees C and 2.48 degrees C for surface temperatures of 36 degrees C and between 0.50 degrees C and 1.63 degrees C for surface temperatures of 38 degrees C. No relevant differences in heat transfer of lower body blankets were found between the different forced-air warming systems tested. Heat transfer was lower than heat transfer by upper body blankets tested in a previous study. However, forced-air warming systems with lower body blankets are still more effective than forced-air warming systems with upper body blankets in the prevention of perioperative hypothermia, because they cover a larger area of the body surface.

Urban surface energy fluxes based on remotely-sensed data and micrometeorological measurements over the Kansai area, Japan

NASA Astrophysics Data System (ADS)

Sukeyasu, T.; Ueyama, M.; Ando, T.; Kosugi, Y.; Kominami, Y.

2017-12-01

The urban heat island is associated with land cover changes and increases in anthropogenic heat fluxes. Clear understanding of the surface energy budget at urban area is the most important for evaluating the urban heat island. In this study, we develop a model based on remotely-sensed data for the Kansai area in Japan and clarify temporal transitions and spatial distributions of the surface energy flux from 2000 to 2016. The model calculated the surface energy fluxes based on various satellite and GIS products. The model used land surface temperature, surface emissivity, air temperature, albedo, downward shortwave radiation and land cover/use type from the moderate resolution imaging spectroradiometer (MODIS) under cloud free skies from 2000 to 2016 over the Kansai area in Japan (34 to 35 ° N, 135 to 136 ° E). Net radiation was estimated by a radiation budget of upward/downward shortwave and longwave radiation. Sensible heat flux was estimated by a bulk aerodynamic method. Anthropogenic heat flux was estimated by the inventory data. Latent heat flux was examined with residues of the energy budget and parameterization of bulk transfer coefficients. We validated the model using observed fluxes from five eddy-covariance measurement sites: three urban sites and two forested sites. The estimated net radiation roughly agreed with the observations, but the sensible heat flux were underestimated. Based on the modeled spatial distributions of the fluxes, the daytime net radiation in the forested area was larger than those in the urban area, owing to higher albedo and land surface temperatures in the urban area than the forested area. The estimated anthropogenic heat flux was high in the summer and winter periods due to increases in energy-requirements.

Using state variables to model the response of tumour cells to radiation and heat: a novel multi-hit-repair approach.

PubMed

Scheidegger, Stephan; Fuchs, Hans U; Zaugg, Kathrin; Bodis, Stephan; Füchslin, Rudolf M

2013-01-01

In order to overcome the limitations of the linear-quadratic model and include synergistic effects of heat and radiation, a novel radiobiological model is proposed. The model is based on a chain of cell populations which are characterized by the number of radiation induced damages (hits). Cells can shift downward along the chain by collecting hits and upward by a repair process. The repair process is governed by a repair probability which depends upon state variables used for a simplistic description of the impact of heat and radiation upon repair proteins. Based on the parameters used, populations up to 4-5 hits are relevant for the calculation of the survival. The model describes intuitively the mathematical behaviour of apoptotic and nonapoptotic cell death. Linear-quadratic-linear behaviour of the logarithmic cell survival, fractionation, and (with one exception) the dose rate dependencies are described correctly. The model covers the time gap dependence of the synergistic cell killing due to combined application of heat and radiation, but further validation of the proposed approach based on experimental data is needed. However, the model offers a work bench for testing different biological concepts of damage induction, repair, and statistical approaches for calculating the variables of state.

Survey report: study of information/educational discussions with private industries and public institutions on the direct-heat utilization of geothermal energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davey, J.V.

1977-03-01

Results of a study of private and public institutions' responses to the proposed use of geothermal energy in the form of direct heat are summarized. This heat energy would be used as an alternate or supportive source for their process or other heat requirements. The summary includes information from over 75 personal contacts with firms in several categories. No attempt is made to reference specific data to any particular company. Although not necessarily confidential, some financial information concerning energy costs to profits was considered sensitive and is respected as such. The companies contacted are in the following categories: food processing--canning,more » drying, dehydration; chemicals; paper/wood-pulp processing; food machinery; horticulture; and dairy. The area covered in the study was from Seattle, Washington, to San Diego, California, during mid-1976. Industry's response varied from mild interest, as with corporations that had little or no knowledge of geothermal energy (and regard it as a new unproven science), to enthusiasm from corporations that employ their own energy departments. The study clearly indicated the need for a basic educational/promotional program and an operating demonstration project (industrial park) to prove economic feasibility and instill confidence in the potential of geothermal energy.« less

Low Cost Nuclear Thermal Rocket Cermet Fuel Element Environment Testing

NASA Technical Reports Server (NTRS)

Bradley, David E.; Mireles, Omar R.; Hickman, Robert R.

2011-01-01

Deep space missions with large payloads require high specific impulse (Isp) and relatively high thrust in order to achieve mission goals in reasonable time frames. Conventional, storable propellants produce average Isp. Nuclear thermal rockets (NTR) capable of high Isp thrust have been proposed. NTR employs heat produced by fission reaction to heat and therefore accelerate hydrogen which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high temperature hydrogen exposure on fuel elements is limited. The primary concern is the mechanical failure of fuel elements which employ high-melting-point metals, ceramics or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. It is not necessary to include fissile material in test samples intended to explore high temperature hydrogen exposure of the structural support matrices. A small-scale test bed designed to heat fuel element samples via non-contact RF heating and expose samples to hydrogen is being developed to assist in optimal material and manufacturing process selection without employing fissile material. This paper details the test bed design and results of testing conducted to date.

Compact Fuel Element Environment Test

NASA Technical Reports Server (NTRS)

Bradley, D. E.; Mireles, O. R.; Hickman, R. R.; Broadway, J. W.

2012-01-01

Deep space missions with large payloads require high specific impulse (I(sub sp)) and relatively high thrust to achieve mission goals in reasonable time frames. Conventional, storable propellants produce average I(sub sp). Nuclear thermal rockets (NTRs) capable of high I(sub sp) thrust have been proposed. NTR employs heat produced by fission reaction to heat and therefore accelerate hydrogen, which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3,000 K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high-temperature hydrogen exposure on fuel elements are limited. The primary concern is the mechanical failure of fuel elements that employ high melting point metals, ceramics, or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. It is not necessary to include fissile material in test samples intended to explore high-temperature hydrogen exposure of the structural support matrices. A small-scale test bed designed to heat fuel element samples via noncontact radio frequency heating and expose samples to hydrogen for typical mission durations has been developed to assist in optimal material and manufacturing process selection without employing fissile material. This Technical Memorandum details the test bed design and results of testing conducted to date.

Prediction of a thermodynamic wave train from the monsoon to the Arctic following extreme rainfall events

NASA Astrophysics Data System (ADS)

Krishnamurti, T. N.; Kumar, Vinay

2017-04-01

This study addresses numerical prediction of atmospheric wave trains that provide a monsoonal link to the Arctic ice melt. The monsoonal link is one of several ways that heat is conveyed to the Arctic region. This study follows a detailed observational study on thermodynamic wave trains that are initiated by extreme rain events of the northern summer south Asian monsoon. These wave trains carry large values of heat content anomalies, heat transports and convergence of flux of heat. These features seem to be important candidates for the rapid melt scenario. This present study addresses numerical simulation of the extreme rains, over India and Pakistan, and the generation of thermodynamic wave trains, simulations of large heat content anomalies, heat transports along pathways and heat flux convergences, potential vorticity and the diabatic generation of potential vorticity. We compare model based simulation of many features such as precipitation, divergence and the divergent wind with those evaluated from the reanalysis fields. We have also examined the snow and ice cover data sets during and after these events. This modeling study supports our recent observational findings on the monsoonal link to the rapid Arctic ice melt of the Canadian Arctic. This numerical modeling suggests ways to interpret some recent episodes of rapid ice melts that may require a well-coordinated field experiment among atmosphere, ocean, ice and snow cover scientists. Such a well-coordinated study would sharpen our understanding of this one component of the ice melt, i.e. the monsoonal link, which appears to be fairly robust.

The Sensitivity of West African Squall Line Water Budgets to Land Cover

NASA Technical Reports Server (NTRS)

Mohr, Karen I.; Baker, R. David; Tao, Wei-Kuo; Famiglietti, James S.; Starr, David OC. (Technical Monitor)

2001-01-01

This study used a two-dimensional coupled land/atmosphere (cloud-resolving) model to investigate the influence of land cover on the water budgets of squall lines in the Sahel. Study simulations used the same initial sounding and one of three different land covers, a sparsely vegetated semi-desert, a grassy savanna, and a dense evergreen broadleaf forest. All simulations began at midnight and ran for 24 hours to capture a full diurnal cycle. In the morning, the latent heat flux, boundary layer mixing ratio, and moist static energy in the boundary layer exhibited notable variations among the three land covers. The broadleaf forest had the highest latent heat flux, the shallowest, moistest, slowest growing boundary layer, and significantly more moist static energy per unit area than the savanna and semi-desert. Although all simulations produced squall lines by early afternoon, the broadleaf forest had the most intense, longest-lived squall lines with 29% more rainfall than the savanna and 37% more than the semi-desert. The sensitivity of the results to vegetation density, initial sounding humidity, and grid resolution was also assessed. There were greater differences in rainfall among land cover types than among simulations of the same land cover with varying amounts of vegetation. Small changes in humidity were equivalent in effect to large changes in land cover, producing large changes in the condensate and rainfall. Decreasing the humidity had a greater effect on rainfall volume than increasing the humidity. Reducing the grid resolution from 1.5 km to 0.5 km decreased the temperature and humidity of the cold pools and increased the rain volume.

Measure Guideline. Steam System Balancing and Tuning for Multifamily Residential Buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Jayne; Ludwig, Peter; Brand, Larry

2013-04-01

This guideline provides building owners, professionals involved in multifamily audits, and contractors insights for improving the balance and tuning of steam systems. It provides readers an overview of one-pipe steam heating systems, guidelines for evaluating steam systems, typical costs and savings, and guidelines for ensuring quality installations. It also directs readers to additional resources for details not included here. Measures for balancing a distribution system that are covered include replacing main line vents and upgrading radiator vents. Also included is a discussion on upgrading boiler controls and the importance of tuning the settings on new or existing boiler controls. Themore » guideline focuses on one-pipe steam systems, though many of the assessment methods can be generalized to two-pipe steam systems.« less

Thermal diode utilizing asymmetric contacts to heat baths.

PubMed

Komatsu, Teruhisa S; Ito, Nobuyasu

2010-01-01

We propose a simple thermal diode passively acting as a rectifier of heat current. The key design of the diode is the size asymmetry of the areas in contact with two distinct heat baths. The heat-conducting medium is liquid, inside of which gaslike regions are induced depending on the applied conditions. Simulating nanoscale systems of this diode, the rectification of heat current is demonstrated. If the packing density of the medium and the working regime of temperature are properly chosen, the heat current is effectively cut off when the heat bath with narrow contact is hotter, but it flows normally under opposite temperature conditions. In the former case, the gaslike region is induced in the system and it acts as a thermal insulator because it covers the entire narrow area of contact with the bath.

Geospatial Strategy for Adverse Impact of Urban Heat Island in upper atmospheres of the earth Mountain Areas using LANDSAT ETM+ Sensors

NASA Astrophysics Data System (ADS)

Kumar, Amit; Vandana, Vandana

2016-07-01

We are living in the age of the rapidly growing population and changing environmental conditions with advanced technical capacity. This has been resulting in widespread land cover change. Among several human-induced environmental and urban thermal problems are reported to be negatively affecting urban residents in many ways. Urban Heat Islands exist in many large cities especially metropolitan cities and can significantly affect the permafrost layer in mountain areas. The adverse effect of urban heat island has become the subject of numerous studies in recent decades and is reflected in many major mountain cities around the world. The built-up structures in urbanized areas considerably alter land cover thereby affecting thermal energy flow which leads to the development of elevated surface and air temperature. The phenomenon Urban Heat Island implies 'island' of high temperature in cities, surrounded by relatively lower temperature in rural areas. The Urban Heat Island for the temporal period is estimated using geospatial techniques which are then utilized for the impact assessment of the climate of the surrounding regions and how it reduce the sustainability of the natural resources like air, vegetation. The knowledge of surface temperature is important for the study of urban climate and human health. The rapid growth of industries in peri-urban areas results in excessive warming and variations in weather conditions. It leads to soil degradation in frozen areas due to high temperature which leads to melting of snow in mountain areas Remotely sensed data of thermal infrared band in the region of 10.4-12.5 µm of EMR spectrum, available from LANDSAT- ETM+ is proved to be very helpful to identify urban heat islands. Thermal infrared data acquired during the daytime and night time can be used to monitor the heat island associated with urban areas as well as atmospheric pollution. The present paper describes the methodology and resolution dynamic urban heat island change on climate and soil using geospatial approach for Haridwar district of Uttrakhand. NDVI were generated using daytime LANDSAT ETM+ image of November 1990, 2000 and 2015. The temperature of various land use and land cover categories was estimated. In Haridwar district, the temperature is inversely related and negatively correlated with NDVI value. The paper considers this dimension and calculated UHI at multiple scales through surface conditions such as vegetation. The major part of the field were conceded out in moderate summer conditions due to rainfall, yet the heat island intensities obtained in the study were comparable to those observed in earlier studies. Moreover, very high UHI was observed in the later phase of the experiments when usual summer conditions were restored. Also, the present study has showed that heat island effect need not be limited to a particular temperature epoch which signals towards the increasing dominance of anthropogenic heat emissions in rapidly developing cities such as Haridwar District in Uttrakhand, India. The use of the technological resources should be such that it does not affect the sustainability of natural resources. For compensation of the adverse effect of UHI, the urban built up cover should be reduced to an extent but in real, it is not possible due to the proclivity of the human towards urbanization. A thick subsurface layer of soil that remains below freezing point throughout the year, occurring chiefly in polar regions.

The Atlanta Urban Heat Island Mitigation and Air Quality Modeling Project: How High-Resoution Remote Sensing Data Can Improve Air Quality Models

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.; Estes, Maurice G., Jr.; Crosson, William L.; Khan, Maudood N.

2006-01-01

The Atlanta Urban Heat Island and Air Quality Project had its genesis in Project ATLANTA (ATlanta Land use Analysis: Temperature and Air quality) that began in 1996. Project ATLANTA examined how high-spatial resolution thermal remote sensing data could be used to derive better measurements of the Urban Heat Island effect over Atlanta. We have explored how these thermal remote sensing, as well as other imaged datasets, can be used to better characterize the urban landscape for improved air quality modeling over the Atlanta area. For the air quality modeling project, the National Land Cover Dataset and the local scale Landpro99 dataset at 30m spatial resolutions have been used to derive land use/land cover characteristics for input into the MM5 mesoscale meteorological model that is one of the foundations for the Community Multiscale Air Quality (CMAQ) model to assess how these data can improve output from CMAQ. Additionally, land use changes to 2030 have been predicted using a Spatial Growth Model (SGM). SGM simulates growth around a region using population, employment and travel demand forecasts. Air quality modeling simulations were conducted using both current and future land cover. Meteorological modeling simulations indicate a 0.5 C increase in daily maximum air temperatures by 2030. Air quality modeling simulations show substantial differences in relative contributions of individual atmospheric pollutant constituents as a result of land cover change. Enhanced boundary layer mixing over the city tends to offset the increase in ozone concentration expected due to higher surface temperatures as a result of urbanization.

Mitigation of Short-Lived Climate Pollutants from Residential Coal Heating and Combined Heating/Cooking Stoves: Impacts on the Cryosphere, Policy Options, and Co-benefits

NASA Astrophysics Data System (ADS)

Chafe, Z.; Anenberg, S.; Klimont, Z.; Kupiainen, K.; Lewis, J.; Metcalfe, J.; Pearson, P.

2017-12-01

Residential solid fuel combustion for cooking, heating, and other energy services contributes to indoor and outdoor air pollution, and creates impacts on the cryosphere. Solid fuel use often occurs in colder climates and at higher elevations, where a wide range of combustion emissions can reduce reflectivity of the snow- and ice-covered surfaces, causing climatic warming. Reducing short-lived climate pollutants (SLCPs), such as black carbon (BC), could have substantial climate and health co-benefits, especially in areas where emissions influence the cryosphere. A review of existing literature and emissions estimates, conducted as part of the Warsaw Summit on BC and Other Emissions from Residential Coal Heating Stoves and Combined Cooking/Heating Stoves, found little nationally-representative data on the fuels and technologies used for heating and combined cooking/heating. The GAINS model estimates that 24 million tonnes of coal equivalent were combusted by households for space heating globally in 2010, releasing 190 kilotons (kt) BC. Emissions from combined cooking/heating are virtually unknown. Policy instruments could mitigate cryosphere-relevant emissions of SLCPs from residential heating or cooking. These include indoor air quality guidelines, stove emission limits, bans on the use of specific fuels, regulatory codes that stipulate when burning can occur, stove changeout programs, and voluntary public education campaigns. These measures are being implemented in countries such as Chile (fuelwood moisture reduction campaign, energy efficiency, heating system improvements), Mongolia (stove renovation, fuel switching), Peru (improved stove programs), Poland (district heating, local fuel bans), United States (stove emission regulation) and throughout the European Community (Ecodesign Directive). Few, if any, of these regulations are likely to reduce emissions from combined cooking/heating. This research team found no global platform to create and share model standards, policies, regulatory instruments, or fiscal approaches that could reduce cryosphere impacts. There has been little coordination between the cookstove and heating stove communities; better communication and success sharing could harmonize efforts and lead to greater mitigation of cryosphere-relevant emissions.

Patterns of Seasonal Heat Uptake and Release Over the Arctic Ocean Between 1979-2016

NASA Astrophysics Data System (ADS)

Helmberger, M. N.; Serreze, M. C.

2017-12-01

As the Arctic Ocean loses its sea ice cover, there is a stronger oceanic heat gain from the surface fluxes throughout the spring and summer; ultimately meaning that there is more energy to transfer out of the ocean to the atmosphere and outer space in the autumn and winter. Recent work has shown that the increased oceanic heat content at the end of summer in turn delays autumn ice growth, with implications for marine shipping and other economic activities. Some of the autumn and winter heat loss to the atmosphere is represented by evaporation, which increases the atmospheric water vapor content, and there is growing evidence that this is contributing to increases in regional precipitation. However, depending on patterns of seasonal sea ice retreat and weather conditions, the spring-summer heat uptake and autumn-winter heat loss can be highly variable from year to year and regionally. Here, we examine how the seasonality in upper ocean heat uptake and release has evolved over the past 37 years and the relationships between this seasonal heat gain and loss and the evolution of sea ice cover. We determine which regions have seen the largest increases in total seasonal heat uptake and how variable this uptake can be. Has the timing at which the Arctic Ocean (either as a whole or by region) transitions from an atmospheric energy sink to an atmospheric energy source (or from a source to a sink) appreciably changed? What changes have been observed in the seasonal rates of seasonal heat uptake and release? To begin answering these questions, use is made of surface fluxes from the ERA-Interim reanalysis and satellite-derived sea ice extent spanning the period 1979 through the present. Results from ERA-Interim will be compared to those from other reanalyses and satellite-derived flux estimates.

Ice patterns and hydrothermal plumes, Lake Baikal, Russia - Insights from Space Shuttle hand-held photography

NASA Technical Reports Server (NTRS)

Evans, Cynthia A.; Helfert, Michael R.; Helms, David R.

1992-01-01

Earth photography from the Space Shuttle is used to examine the ice cover on Lake Baikal and correlate the patterns of weakened and melting ice with known hydrothermal areas in the Siberian lake. Particular zones of melted and broken ice may be surface expressions of elevated heat flow in Lake Baikal. The possibility is explored that hydrothermal vents can introduce local convective upwelling and disrupt a stable water column to the extent that the melt zones which are observed in the lake's ice cover are produced. A heat flow map and photographs of the lake are overlaid to compare specific areas of thinned or broken ice with the hot spots. The regions of known hydrothermal activity and high heat flow correlate extremely well with circular regions of thinned ice, and zones of broken and recrystallized ice. Local and regional climate data and other sources of warm water, such as river inlets, are considered.

Introduction to Heating, Ventilation and Air Conditioning (HVAC). Introduction to Construction Series. Instructor Edition.

ERIC Educational Resources Information Center

Associated General Contractors of America, Washington, DC.

This module on introductory heating, ventilating, and air conditioning (HVAC) is one of a series of modules designed to teach basic skills necessary for entry-level employment in this field. The module contains four instructional units that cover the following topics: (1) HVAC materials; (2) HVAC tools; (3) HVAC layout; and (4) HVAC basic skills.…

Heating and Ventilating IV, 11-5. Military Curriculum Materials for Vocational and Technical Education.

ERIC Educational Resources Information Center

Army Engineer School, Fort Belvoir, VA.

This fourth course in a four-course series on heating and ventilating for the secondary/postsecondary level is one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. The four lessons in the course cover these topics: (1) Feed-Water, Condensate,…

Colonization by Cladosporium spp. of painted metal surfaces associated with heating and air conditioning systems

NASA Technical Reports Server (NTRS)

Ahearn, D. G.; Simmons, R. B.; Switzer, K. F.; Ajello, L.; Pierson, D. L.

1991-01-01

Cladosporium cladosporioides and C. hebarum colonized painted metal surfaces of covering panels and register vents of heating, air conditioning and ventilation systems. Hyphae penetrated the paint film and developed characteristic conidiophores and conidia. The colonies were tightly appressed to the metal surface and conidia were not readily detectable via standard air sampling procedures.

Energy Smart Guide to Campus Cost Savings: Today's Trends in Project Finance, Clean Fuel Fleets, Combined Heat& Power, Emissions Markets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2003-07-01

The Energy Smart Guide to Campus Cost Savings covers today's trends in project finance, combined heat& power, clean fuel fleets and emissions trading. The guide is directed at campus facilities and business managers and contains general guidance, contact information and case studies from colleges and universities across the country.

THE SCHOOL PLANT GUIDE FOR PLANNING SCHOOL PLANTS OF PENNSYLVANIA. ARCHITECTURAL DESIGN REQUIREMENTS AND GENERAL, ELECTRIC, HEATING AND VENTILATING, AND PLUMBING STANDARDS.

ERIC Educational Resources Information Center

Pennsylvania State Dept. of Public Instruction, Harrisburg.

A GUIDE COVERING ARCHITECTURAL DESIGN REQUIREMENTS, ELECTRIC, HEATING AND VENTILATING, AND PLUMBING STANDARDS AS APPROVED BY THE STATE BOARD OF EDUCATION IN 1966. THE FOLLOWING MINIMUM STANDARD FOR NEW BUILDING, ALTERATIONS, AND ADDITIONS ARE OUTLINED--(1) SPATIAL ENVIRONMENTAL FACTORS, SUCH AS CEILING HEIGHTS, INTERIOR SANITARY FACILITIES, ROOMS…

Plug into a Great Outlet for Creativity

ERIC Educational Resources Information Center

Skophammer, Karen

2009-01-01

Is there beauty in the wall socket that people plug their appliances into daily? Can one find beauty in the grate covering the heat vent in his classroom? The author posed these very questions to her third-grade students. She had the students take a good look at the outlet cover (or plate) on the wall. After thinking and discussing the outlets,…

Sensitivity of Great Lakes Ice Cover to Air Temperature

NASA Astrophysics Data System (ADS)

Austin, J. A.; Titze, D.

2016-12-01

Ice cover is shown to exhibit a strong linear sensitivity to air temperature. Upwards of 70% of ice cover variability on all of the Great Lakes can be explained in terms of air temperature, alone, and nearly 90% of ice cover variability can be explained in some lakes. Ice cover sensitivity to air temperature is high, and a difference in seasonally-averaged (Dec-May) air temperature on the order of 1°C to 2°C can be the difference between a low-ice year and a moderate- to high- ice year. The total amount of seasonal ice cover is most influenced by air temperatures during the meteorological winter, contemporaneous with the time of ice formation. Air temperature conditions during the pre-winter conditioning period and during the spring melting period were found to have less of an impact on seasonal ice cover. This is likely due to the fact that there is a negative feedback mechanism when heat loss goes toward cooling the lake, but a positive feedback mechanism when heat loss goes toward ice formation. Ice cover sensitivity relationships were compared between shallow coastal regions of the Great Lakes and similarly shallow smaller, inland lakes. It was found that the sensitivity to air temperature is similar between these coastal regions and smaller lakes, but that the absolute amount of ice that forms varies significantly between small lakes and the Great Lakes, and amongst the Great Lakes themselves. The Lake Superior application of the ROMS three-dimensional hydrodynamic numerical model verifies a deterministic linear relationship between air temperature and ice cover, which is also strongest around the period of ice formation. When the Lake Superior bathymetry is experimentally adjusted by a constant vertical multiplier, average lake depth is shown to have a nonlinear relationship with seasonal ice cover, and this nonlinearity may be associated with a nonlinear increase in the lake-wide volume of the surface mixed layer.

Experimental Performance of a Micromachined Heat Flux Sensor

NASA Technical Reports Server (NTRS)

Stefanescu, S.; DeAnna, R. G.; Mehregany, M.

1998-01-01

Steady-state and frequency response calibration of a microfabricated heat-flux sensor have been completed. This sensor is batch fabricated using standard, micromachining techniques, allowing both miniaturization and the ability to create arrays of sensors and their corresponding interconnects. Both high-frequency and spatial response is desired, so the sensors are both thin and of small cross-sectional area. Thin-film, temperature-sensitive resistors are used as the active gauge elements. Two sensor configurations are investigated: (1) a Wheatstone-bridge using four resistors; and (2) a simple, two-resistor design. In each design, one resistor (or pair) is covered by a thin layer (5000 A) thermal barrier; the other resistor (or pair) is covered by a thick (5 microns) thermal barrier. The active area of a single resistor is 360 microns by 360 microns; the total gauge area is 1.5 mm square. The resistors are made of 2000 A-thick metal; and the entire gauge is fabricated on a 25 microns-thick flexible, polyimide substrate. Heat flux through the surface changes the temperature of the resistors and produces a corresponding change in resistance. Sensors were calibrated using two radiation heat sources: (1) a furnace for steady-state, and (2) a light and chopper for frequency response.

Solar heating and hot water system installed at Southeast of Saline, Unified School District 306, Mentor, Kansas

NASA Technical Reports Server (NTRS)

1979-01-01

The solar system, installed in a new building, was designed to provide 52 percent of the estimated annual space heating load and 84 percent of the estimated annual potable hot water requirement. The liquid flat plate collectors are ground-mounted and cover a total area of 5125 square feet. The system will provide supplemental heat for the school's closed-loop water-to-air heat pump system and domestic hot water. The storage medium is water inside steel tanks with a capacity of 11,828 gallons for space heating and 1,600 gallons for domestic hot water. The solar heating facility is described and drawings are presented of the completed system which was declared operational in September 1978, and has functioned successfully since.

Solar dynamic heat rejection technology. Task 2: Heat pipe radiator development

NASA Technical Reports Server (NTRS)

League, Mark; Alario, Joe

1988-01-01

This report covers the design, fabrication, and test of several dual slot heat pipe engineering development units. The following dual-slot heat pipes were fabricated and tested: two 6-ft. aluminum heat pipes; a 20-ft. aluminum heat pipe; and a 20-ft. aluminum heat pipe with a four-leg evaporator section. The test results of all four test articles are presented and compared to the performance predicted by the design software. Test results from the four-leg article are incomplete. The methodology for fabricating stainless steel dual slot heat pipes was also studied by performing a tool life test with different single point cutters, and these results are also presented. Although the dual-slot heat pipe has demonstrated the potential to meet the requirements for a high capacity radiator system, uncertainties with the design still exist. The startup difficulties with the aluminum test articles must be solved, and a stainless steel/methanol heat pipe should be built and tested.

Summer temperature variability across four urban neighborhoods in Knoxville, Tennessee, USA

NASA Astrophysics Data System (ADS)

Ellis, Kelsey N.; Hathaway, Jon M.; Mason, Lisa Reyes; Howe, David A.; Epps, Thomas H.; Brown, Vincent M.

2017-02-01

The urban heat island (UHI) is a well-documented effect of urbanization on local climate, identified by higher temperatures compared to surrounding areas, especially at night and during the warm season. The details of a UHI are city-specific, and microclimates may even exist within a given city. Thus, investigating the spatiotemporal variability of a city's UHI is an ongoing and critical research need. We deploy ten weather stations across Knoxville, Tennessee, to analyze the city's UHI and its differential impacts across urban neighborhoods: two each in four neighborhoods, one in more dense tree cover and one in less dense tree cover, and one each in downtown Knoxville and Ijams Nature Center that serve as control locations. Three months of temperature data (beginning 2 July 2014) are analyzed using paired-sample t tests and a three-way analysis of variance. Major findings include the following: (1) Within a given neighborhood, tree cover helps negate daytime heat (resulting in up to 1.19 ∘C lower maximum temperature), but does not have as large of an influence on minimum temperature; (2) largest temperature differences between neighborhoods occur during the day (0.38-1.16 ∘C difference), but larger differences between neighborhoods and the downtown control occur at night (1.04-1.88 ∘C difference); (3) presiding weather (i.e., air mass type) has a significant, consistent impact on the temperature in a given city, and lacks the differential impacts found at a larger-scale in previous studies; (4) distance from city center does not impact temperature as much as land use factors. This is a preliminary step towards informing local planning with a scientific understanding of how mitigation strategies may help minimize the UHI and reduce the effects of extreme weather on public health and well-being.

Turbulent Surface Flux Measurements over Snow-Covered Sea Ice

NASA Astrophysics Data System (ADS)

Andreas, E. L.; Fairall, C. W.; Grachev, A. A.; Guest, P. S.; Jordan, R. E.; Persson, P. G.

2006-12-01

Our group has used eddy correlation to make over 10,000 hours of measurements of the turbulent momentum and heat fluxes over snow-covered sea ice in both the Arctic and the Antarctic. Polar sea ice is an ideal site for studying fundamental processes for turbulent exchange over snow. Both our Arctic and Antarctic sites---in the Beaufort Gyre and deep into the Weddell Sea, respectively---were expansive, flat areas with continuous snow cover; and both were at least 300 km from any topography that might have complicated the atmospheric flow. In this presentation, we will review our measurements of the turbulent fluxes of momentum and sensible and latent heat. In particular, we will describe our experiences making turbulence instruments work in the fairly harsh polar, marine boundary layer. For instance, several of our Arctic sites were remote from our main camp and ran unattended for a week at a time. Besides simply making flux measurements, we have been using the data to develop a bulk flux algorithm and to study fundamental turbulence processes in the atmospheric surface layer. The bulk flux algorithm predicts the turbulent surface fluxes from mean meteorological quantities and, thus, will find use in data analyses and models. For example, components of the algorithm are already embedded in our one- dimensional mass and energy budget model SNTHERM. Our fundamental turbulence studies have included deducing new scaling regimes in the stable boundary layer; examining the Monin-Obukhov similarity functions, especially in stable stratification; and evaluating the von Kármán constant with the largest atmospheric data set ever applied to such a study. During this presentation, we will highlight some of this work.

The Urban Heat Island Behavior of a Large Northern Latitude Metropolitan Area

NASA Astrophysics Data System (ADS)

Twine, T. E.; Snyder, P. K.; Hertel, W.; Mykleby, P.

2012-12-01

Urban heat islands (UHIs) occur when urban and suburban areas experience elevated temperatures relative to their rural surroundings because of differences in vegetation cover, buildings and other development, and infrastructure. Most cities in the United States are warming at twice the rate of the outlying rural areas and the planet as a whole. Temperatures in the urban center can be 2-5°C warmer during the daytime and as much as 10°C at night. Urban warming is responsible for excessive energy consumption, heat-related health effects, an increase in urban pollution, degradation of urban ecosystems, changes in the local meteorology, and an increase in thermal pollution into urban water bodies. One mitigation strategy involves manipulating the surface energy budget to either reduce the amount of solar radiation absorbed at the surface or offset absorbed energy through latent cooling. Options include using building materials with different properties of reflectivity and emissivity, increasing the reflectivity of parking lots, covering roofs with vegetation, and increasing the amount of vegetation overall through tree planting or increasing green space. The goal of the Islands in the Sun project is to understand the formation and behavior of urban heat islands and to mitigate their effects through sensible city engineering and design practices. As part of this project, we have been characterizing the UHI of the Twin Cities Metropolitan Area (TCMA), a 16,000 square kilometer urban and suburban region located in east central Minnesota that includes the two cities of Minneapolis and Saint Paul, and evaluating mitigation strategies for reducing urban warming. Annually, the TCMA has a modest 2-3°C UHI that is especially apparent in winter when the urban core can be up to 5-6°C warmer than the surrounding countryside. We present an analysis of regional temperature variations from a dense network of sensors located throughout the TCMA. We focus on the diurnal and seasonal behavior of the TCMA UHI with an emphasis on the contribution of different land use types on the UHI. We also present a comparison of thermal and radiative properties of two different roofing materials with data collected from the roof of the Science Museum of Minnesota in Saint Paul, MN. The impact of the TCMA UHI on thermal pollution into local water bodies is also investigated.

Impact of future fuel properties on aircraft engines and fuel systems

NASA Technical Reports Server (NTRS)

Rudey, R. A.; Grobman, J. S.

1978-01-01

The effect of modifications in hydrocarbon jet fuels specifications on engine performance, component durability and maintenance, and aircraft fuel system performance is discussed. Specific topics covered include: specific fuel consumption; ignition at relight limits; exhaust emissions; combustor liner temperatures; carbon deposition; gum formation in fuel nozzles, erosion and corrosion of turbine blades and vanes; deposits in fuel system heat exchangers; and pumpability and flowability of the fuel. Data that evaluate the ability of current technology aircraft to accept fuel specification changes are presented, and selected technological advances that can reduce the severity of the problems are described and discussed.

Orion Splashdown Recovery

NASA Image and Video Library

2014-12-05

NASA's Orion spacecraft floats in the Pacific Ocean after splashdown from its first flight test in Earth orbit. The spacecraft completed a two-orbit, four-and-a-half-hour mission in Earth orbit. NASA, the U.S. Navy and Lockheed Martin are coordinating efforts to recover Orion, the forward bay cover and main parachutes. Orion will be towed in and secure in the well deck of the nearby USS Anchorage. Orion's mission tested systems critical to crew safety, including the launch abort system, the heat shield and the parachute system. The Ground Systems Development and Operations Program is leading the recovery efforts.

Production of porous coating on a prosthesis

DOEpatents

Sump, Kenneth R.

1987-01-01

Preselected surface areas of a prosthesis are covered by a blend of matching primary metallic particles and expendable particles. The particles are compressed and heated to assure that deformation and metallurgical bonding occurs between them and between the primary particles and the surface boundaries of the prosthesis. Porosity is achieved by removal of the expendable material. The result is a coating including discrete bonded particles separated by a network of interconnected voids presenting a homogeneous porous coating about the substrate. It has strength suitable for bone implant usage without intermediate adhesives, and adequate porosity to promote subsequent bone ingrowth.